Top Ten Reasons Why Subwoofers and B&W Loudspeakers Don't Mix Musically... Usually

[Kobus]

Help me understand this please, and I hope that I can put my question across understandably.

First, I assume that the SMS-1 address the base from the sub only and not that of your full range mains. If I am wrong, then this post can be ignored.

Say, as an example, I set the crossover at 50 Hz. Now the base below 50 will get “modified” to suit the room and the base above that will not.

From a music perspective that can not be right or good, surely. Or am I missing something.

Am I making myself clear!

Kobus

[Karma]

It doesn't pertain to the topic of B&W loudspeakers and subwoofers specifically. And yes I am partially guilty.

Now you do. :T

HI,
Yes, I agree about the time element. We must understand that the listening experience and audio nirvana are moving targets. Two basic things are in constant change and they interact in very complex ways.

First, the equipment is changing. Usually, but not always, equipment is getting better. This means that sonics that were previously obscured are now audible. A good example is imaging and sound staging. If you listen to older equipment they always lack modern pin point imaging and normally don't precisely define a sound stage. Another example is detail. Fine textures and very low level sounds are always missing in action with older equipment.

Next, since we have never heard the changed sonics before, except hopefully with live music, we must adapt to them and learn. Some folks, those that are into vintage equipment, never adapt and continue to prefer the older sound. That's fine for them. But for those of use that are entranced with the learning experience, we must and will adapt. But this takes time. While the learning is going on we are developing our sonic tastes.

With a lot of experience we realize what our general sonic goals and tastes are. To complicate the matter further, no two people physically hear exactly the same way. Thus, we are almost totally on our own. This is good. It is this that makes the listening experience fundamentally creative. It's what we live for.

I have said, and believe, that it may take a lifetime to come to an understanding of our personal listening experience. And experience is the only tool we have.

There are no shortcuts.

Sparky

[hifiguymi]

I do understand where RebelMan is coming from with this thread and used to think the same things. In an ideal world he's right, but most peoples room are far from ideal. Treating a room to compensate for frequency response problems does not work for a lot of people. As good as some room treatments look; they still look out of place in most homes. I'm talking generally here, not all of the time. If an individual can treat their listening room then great, more power to them. If you can't, then use what tools you have available to enjoy the music and/or music you like the way you like to hear it in your room. All of this is about fun and if someone enjoys their system more by having an EQ in their system, then so be it.

Not everyone has the ability to purchase full range speakers and the amps to drive them so a sub with and EQ is better than a sub without that sounds bad. The argument that RebelMan has made, that someone is changing what was intended by the artist by adding an EQ is bad, but the reason we choose the products we do is because of the sound they make. Every speaker company, every electronics company, and every video display company all believe that their product is the most true to the original source material. The truth is all of them change it in some way. Let me say it again, they all change it in some way. That is, in itself, a version of an EQ. If an EQ is used correctly to compensate for room problems with the goal of better sound then there is nothing wrong with that in my opinion. As I stated before, this is all about having fun, so do what you like as long as you have fun in the end.

I stopped trying to save the world from bad Hi-Fi long ago and just got down to having fun with it for my customer’s sake and mine. So add a subwoofer, and an EQ if you would like, and enjoy your systems.

One other thing. More than once the word for the low frequency audio range has been spelled base. It's bass if it's referring to the low frequency band in music.

Eric

[yannparis]

Help me understand this please, and I hope that I can put my question across understandably.

First, I assume that the SMS-1 address the base from the sub only and not that of your full range mains. If I am wrong, then this post can be ignored.

Say, as an example, I set the crossover at 50 Hz. Now the base below 50 will get “modified” to suit the room and the base above that will not.

From a music perspective that can not be right or good, surely. Or am I missing something.

Am I making myself clear!

Kobus

Hi
I use a Velodyne DD18 with my 802d. (SSP600/bi-amp 5100).

I agree with the fact that is useless to modify the behaviour of the main speaker between 200 Hz (depending of your room) and above.
Using a DSP on this frequency band change the ‘sound’ you have bought. It is useful only if you want to generate effects (like ‘Horn sound’ for movies, optimizing a 5.1 system with calculated virtual speaker) or if you have a complex room.

Above this frequency, it is very different. A 802d is an intelligent trade-off but a trade-off between efficiency, size, price, marketing, design and bass quality.
The main reason is that the ratio between bass wave lengths and the size of the loudspeaker reduces the efficiency of a woofer and its SPL capacity. The usual solution is to use a resonance, like a bass reflex to increase the efficiency. The price to pay is a degraded transient response (delay), a non linear response (meaning Harmonic Distorsion) and a bad behaviour below the port tuning frequency (i.e. a free air like). Simply look at the THD vs. frequency figures of the 801 or 800.
A good subwoofer uses generally a sealed enclosure, a large long throw loudspeaker and a powerful amplifier. As bass sounds are slow, it is also easy to had a servo to reduce further non linearity induces by the motor, air compression and the loudspeaker suspension.
The result is a better transient response and less unwanted harmonics and or new frequency generated by non linearity (intermodulation).

It takes a long times to optimize the 802D +DD18 + Room system.
DD18 parameters allow having a soft transition between the main loudspeaker and the sub (the phase parameter is a delay and allows that). I have calculated the resonance of my room (You have to calculate the resonance frequencies to find a good placement for the sub to reduce them before any equalisation. Equalization is not magic)
I have also put a filled sock in the B&W port.
Deep bass are realistic, clean and powerful. You could not notice any transition. Upper bass are also upgraded are there is no longer any harmonic covering them. The sound is more dynamic.
The bonus is that as the DD18 takes a large part of the signal energy, it reduces the main amplifier work and required power and current

Regards,

Yann, Paris

[dmccombs]

Kobus,

You are correct. The SMS-1 only corrects signals sent to the sub, and will not modify the signal to the mains.

Regards,
Darrell

Help me understand this please, and I hope that I can put my question across understandably.

First, I assume that the SMS-1 address the base from the sub only and not that of your full range mains. If I am wrong, then this post can be ignored.

Say, as an example, I set the crossover at 50 Hz. Now the base below 50 will get “modified” to suit the room and the base above that will not.


Kobus

[RebelMan]

Every speaker company, every electronics company, and every video display company all believe that their product is the most true to the original source material. The truth is all of them change it in some way. Let me say it again, they all change it in some way. That is, in itself, a version of an EQ.

Yes, it could be viewed that way. However, as I see it, the philosophies are (in general) quite different. The difference meaning that one philosophy attempts to avoid signal alterations while the other promotes it. Like you said, and which I pointed out at the beginning of this thread, people should do what provides them with the most satisfaction. This comes with the understanding that a modified Honda Civic can offer great fun too but it is no McLaren F1. It's only a modified Honda Civic.

[RebelMan]

HI,
Yes, I agree about the time element. We must understand that the listening experience and audio nirvana are moving targets. Two basic things are in constant change and they interact in very complex ways.

First, the equipment is changing. Usually, but not always, equipment is getting better. This means that sonics that were previously obscured are now audible. A good example is imaging and sound staging. If you listen to older equipment they always lack modern pin point imaging and normally don't precisely define a sound stage. Another example is detail. Fine textures and very low level sounds are always missing in action with older equipment.

Next, since we have never heard the changed sonics before, except hopefully with live music, we must adapt to them and learn. Some folks, those that are into vintage equipment, never adapt and continue to prefer the older sound. That's fine for them. But for those of use that are entranced with the learning experience, we must and will adapt. But this takes time. While the learning is going on we are developing our sonic tastes.

With a lot of experience we realize what our general sonic goals and tastes are. To complicate the matter further, no two people physically hear exactly the same way. Thus, we are almost totally on our own. This is good. It is this that makes the listening experience fundamentally creative. It's what we live for.

I have said, and believe, that it may take a lifetime to come to an understanding of our personal listening experience. And experience is the only tool we have.

There are no shortcuts.

Sparky

Nicely put Sparky.

[dknightd]

I think perhaps one of the causes for disagreement in this thread might be one of money.

James Dean seems to have lots of money and is happy to to let the speaker manufacturer EQ his speakers for him. Others have to get more bang for their buck,
and are willing to spend a little time trying to reproduce the sound they want using
cheaper alternatives.

Let me ask you one thing Mr Dean, what were you using for speakers 5 years ago?

Of course, I could be wrong, and no disrespect is intended.

[beden1]

This comes with the understanding that a modified Honda Civic can offer great fun too but it is no McLaren F1. It's only a modified Honda Civic.

I'm not sure I follow this statement. Are you comparing your system and setup to a McLaren F1? The McLaren F1 would be considered by most car enthusiasts to be the near nirvana of sport automobiles. I thought I read that you felt your system was not nirvana?

[RebelMan]

I think perhaps one of the causes for disagreement in this thread might be one of money.

Of course, I could be wrong, and no disrespect is intended.

I am just a run-of-the-mill Systems Engineer working for a Fortune 100 company in the IT industry and not as affluent as you might think. My good fortune came with the deal I made.

In some ways I prefer my previous 803S over the 800D that I have now. The all veneer cabinet that blankets the 803S is visually flawless. The 800D is strikingly beautiful but the plinth is esthetically crippled. My HTM3S mated seamlessly with the 803S. My 800D has no center to mate with. Maneuvering the 803S can be effortless. The 800D can be stubborn to move.

Regarding performance, clearly the 803S are out gunned by the 800D, no question. What does this imply? That the 800D is superior or that the 803S is inferior? The outcome could be either or neither or both.

When a friend came by to evaluate my B&W and Rotel based system more than a year ago he was please with the results but not completely free from certain criticisms, to which I agreed. Later he and I were extended an invitation to a private viewing of a top-of-the-line state-of-the-art McIntosh system.

My system consisted of a pair of 803S and HTM3S a pair of SCMS an ASW-825 an RCD-1072, RDV-1050, an RB-1080 and RSX-1056. The McIntosh system included four XRT2K an XCS2K an MDA1000 and MCD1000 a C1000 a pair of MC2KW and seven MC1201s. The retail price of my system was around $17K, the retail price of the McIntosh system was around $400K. My room: average size and partially treated, the McIntosh room: considerable size and fully treated. Neither system was augmented with subwoofers or any EQ’s for stereo playback.

The feedback from my friend was, and I quote… “I think I like the sound of your system a little better overall.” Putting this all into perspective goes to show that a system needn’t be expensive to perform well. It only needs to be well put together. :T

[RebelMan]

I'm not sure I follow this statement. Are you comparing your system and setup to a McLaren F1? The McLaren F1 would be considered by most car enthusiasts to be the near nirvana of sport automobiles. I thought I read that you felt your system was not nirvana?

LOL, the translation is this... some products are designed (from the ground up) to make the most of every drop of fuel and some products aren't. :W

[Gump]

I do understand where RebelMan is coming from with this thread and used to think the same things. In an ideal world he's right, but most peoples room are far from ideal. Treating a room to compensate for frequency response problems does not work for a lot of people. As good as some room treatments look; they still look out of place in most homes. I'm talking generally here, not all of the time. If an individual can treat their listening room then great, more power to them. If you can't, then use what tools you have available to enjoy the music and/or music you like the way you like to hear it in your room. All of this is about fun and if someone enjoys their system more by having an EQ in their system, then so be it.

Not everyone has the ability to purchase full range speakers and the amps to drive them so a sub with and EQ is better than a sub without that sounds bad. The argument that RebelMan has made, that someone is changing what was intended by the artist by adding an EQ is bad, but the reason we choose the products we do is because of the sound they make. Every speaker company, every electronics company, and every video display company all believe that their product is the most true to the original source material. The truth is all of them change it in some way. Let me say it again, they all change it in some way. That is, in itself, a version of an EQ. If an EQ is used correctly to compensate for room problems with the goal of better sound then there is nothing wrong with that in my opinion. As I stated before, this is all about having fun, so do what you like as long as you have fun in the end.

I stopped trying to save the world from bad Hi-Fi long ago and just got down to having fun with it for my customer’s sake and mine. So add a subwoofer, and an EQ if you would like, and enjoy your systems.

One other thing. More than once the word for the low frequency audio range has been spelled base. It's bass if it's referring to the low frequency band in music.

Eric

I know what you mean, I caught a Largemouth Base once----or was it a Bass....hmmmm?

[beden1]

LOL, the translation is this... some products are designed (from the ground up) to make the most of every drop of fuel and some products aren't. :W

RebelMan

As a car enthusiast, I was just sticking it to you a bit . . . respectfully, and all in good fun.

Actually, I'm sorry to hear that you feel your system is not close to nirvana. Except for the center channel speaker short coming (as you have mentioned), I could only hope that a setup likes yours would be pretty close to an ultimate. I think you could certainly equate your system to a Ferrari F430 (my personal dream car, although I am having to compromise with ordering a ZO6 Corvette :B ).

While I mention the center channel speaker . . . I also have a mis-match with an HTM1 along with 803D fronts. I'm having a real hard time in justifying the cost of an HTM2D as it may also be a compromise, instead of having an 803D as a center speaker. Unfortunately however, I can't see how to position a third 803D without totally butchering our living room and giving my wife more fits.

How much is lost by eliminating the center channel altogether, and just using the front 803Ds in a phantom setting? Or, is it the lesser evil of compromises?

I started a thread for this question in the B&W Forum.

[ZX10 Guy]

Let's just refocus for a bit. The point of argument and contention was about subs and integration into the overall system. I brought up the SMS EQ as a great tool to help someone dial in the sub to better integrate into one's system and to also have better bass performance taking into account the room's contribution to the sound. The issue got pulled off track by broading the aspect of using an EQ for the entire frequency range or to imply the SMS-1 does any EQ above the bass frequencies.

I have and will always promote the room to be fixed first before anything else. Also as I've said all along, the SMS-1 is a great tool to do that final bit of adjustment to deal with any resonances or room mode issues you may have that no amount of acoustical treatment could solve. The ability for you to measure your exact in room response makes the SMS worth at least part of the admission price. I doubt very many of you all have any idea how your system is performing (bass wise to keep it relevant to this thread) in your room. I dogged RebelMan about his statement that his 800Ds were performing at 32Hz with +/- 3 dB accuracy because he threw out those numbers like they were fact and he had done the measurements. I know how my system is performing bass wise in my room because I have the measurements to prove it.

Also let's get on the topic of bass and why it's a different animal than mid and high frequencies which are being lumped into this discussion. Bass being reflected in the room doesn't suffer from the echo effect that mid and high frequencies do. Depending on the room the reflected bass frequencies can sometimes combine to create standing waves that either artificially boost certain frequencies or cancel/nullify each other out. That's why bass traps are employed to help absorb some of the reflected bass frequencies. And this is also why a square room is always detrimental to bass performance. Another issue I raised about having even full range speakers produce low end bass is due to the inevitable distortion that occurs when you drive "small" woofers beyond their linear operating range. The more cone movement of the woofer, the more distortion. Period. Depending on the size of the room, having dual 10s or a large 15 won't be able to keep up. Subs are optimized to reproduce the end bass. Subs allow flexibility of placement of subs where optimal bass is reproduced which is many times not the same placement you would put your main speakers for imaging and soundstaging. The subs which many agree produces the best musicality are sealed servo controlled subs. Having a servo which monitors cone movement and adjusts for any non linearity produces great bass response with low distortion. And with anything bass related, moving air is king. Being able to use an 18" driver is a luxury that can only be done with a sub. With all the subs we are talking about, every one of them has their own amplifier. To alleviate the mains from having to reproduce low end bass has benefits I've discussed before. Those being better efficiency of the amp driving the mains and lower bass distortion as your not pushing the woofers in your mains into non-linear operation. And to make it clear, no where in my discussion has there been any talk about overboosting the bass reproduction. All my postings have been to achieve the best balanced bass response.

A side question for the purists. Any of you all run your system through a processor? Do you have settings programmed into your processor indicating how far your speakers are from your listening position? If you do, you're corrupting your signal due to the processor adding equalizing the audio to compensate for the speaker distances.

[ZX10 Guy]

RebelMan

As a car enthusiast, I was just sticking it to you a bit . . . respectfully, and all in good fun.

Actually, I'm sorry to hear that you feel your system is not close to nirvana. Except for the center channel speaker short coming (as you have mentioned), I could only hope that a setup likes yours would be pretty close to an ultimate. I think you could certainly equate your system to a Ferrari F430 (my personal dream car, although I am having to compromise with ordering a ZO6 Corvette :B ).

While I mention the center channel speaker . . . I also have a mis-match with an HTM1 along with 803D centers. I'm having a real hard time in justifying the cost of an HTM2D as it may also be a compromise, instead of having an 803D as a center speaker. Unfortunately however, I can't see how to position a third 803D without totally butchering our living room and giving my wife more fits.

How much is lost by eliminating the center channel altogether, and just using the front 803Ds in a phantom setting? Or, is it the lesser evil of compromises?

All center channel speakers are compromise. Anyone who tells you differently is misleading you. The only way to get the best performance is to run the same speaker you have for your L/R mains. If you must run a center, it's best to use a center which doesn't have the MTM arrangement which none of the 800 series center speakers has AND to have the center speaker as close in height as your mains to get the midrange and tweeter to the same height. Dropping the center and running a phantom depends on your listening habits and the setup of your main speakers. Having a phantom center would be preferable than to having your center misplaced due to aesthetic reasons.

[RebelMan]

RebelMan

As a car enthusiast, I was just sticking it to you a bit . . . respectfully, and all in good fun.

Actually, I'm sorry to hear that you feel your system is not close to nirvana. Except for the center channel speaker short coming (as you have mentioned), I could only hope that a setup likes yours would be pretty close to an ultimate. I think you could certainly equate your system to a Ferrari F430 (my personal dream car, although I am having to compromise with ordering a ZO6 Corvette :B ).

No worries about the jab and if I might add the ZO6 is a very respectable compromise. :T

If my system could equate to an F430 it would be like a Sunday afternoon cruise through the neighborhood with an occasional spin on the Interstate. LOL Still 70% of what I have presently is more than 90% of what I had previously. Eventually, I'll take it to the Autobahn!

[beden1]

No worries about the jab and if I might add the ZO6 is a very respectable compromise. :T

I'm not complaining. I always try and get the best bang for the buck. In this case, I figured it was time to replace my modified '01 Corvette. It will be my fourth Corvette and I'm looking forward to driving this beast when it comes in around the beginning of September. :nos:

[Alaric]

Just for S&Gs...

Having been to many live musical performances over the last 25 or so years-most concerts don't have the bass subwoofers produce. Maybe if I sat on the violin cello I would 'feel' it , but from the fifth row-it ain't there. I believe sub-woofers produce a wonderful effect for HT. I also believe they produce nothing but distortion and cr@p for most music. Making audible sounds that weren't on the master isn't "music"-it's electronic junk. My $.02

[ZX10 Guy]

Having been to many live musical performances over the last 25 or so years-most concerts don't have the bass subwoofers produce. Maybe if I sat on the violin cello I would 'feel' it , but from the fifth row-it ain't there. I believe sub-woofers produce a wonderful effect for HT. I also believe they produce nothing but distortion and cr@p for most music. Making audible sounds that weren't on the master isn't "music"-it's electronic junk. My $.02

That's pretty closed minded to think all live musical performance revolve around the classical performances you prefer. I've been to plenty of live jazz performances where the bass was every bit as powerfull as many movie sound tracks. The concert I attended at the Troy Music Hall where Chick Corea and the Electrik Band performed comes to mind.

And explain to me how these subs are producing these mysterious "audible sounds" when they're just producing what is being fed into them? I guess all subs have this hidden electronic junk box that just makes spurious low frequency noises for all sub lovers to just experience chest jabbing bass. :roll:

[RebelMan]

The point of argument and contention was about subs and integration into the overall system. I brought up the SMS EQ as a great tool to help someone dial in the sub to better integrate into one's system and to also have better bass performance taking into account the room's contribution to the sound. The issue got pulled off track by broading the aspect of using an EQ for the entire frequency range or to imply the SMS-1 does any EQ above the bass frequencies.

The point of this discussion revolves around subwoofers trying to produce mid-bass stereo for which they were not designed but which full-range loudspeakers were. EQ’s used in any “blending” capacity is harmful to stereo regardless of the specific instrument employed to the task, freedoms of enjoyment not withstanding.

The SMS-1 (specifically) is an expensive special-effects toy, period. Anyone that would invest in elaborate gimmickry rather than making the effort to implement the tried and true speaks volumes (pun) where priorities lie on high-end audio. Absolutely nothing wrong with that but if it looks like a duck, walks like and duck and quacks like a duck, then it must be a duck. LOL

A side question for the purists. Any of you all run your system through a processor? Do you have settings programmed into your processor indicating how far your speakers are from your listening position? If you do, you're corrupting your signal due to the processor adding equalizing the audio to compensate for the speaker distances.

I would consider myself more of an audio "truist", if there were such a word, rather than purist but the latter suits me just fine. I happily profess to using a sound processor as I see no alternatives. Besides it’s a required staple in any home theater. And I freely admit to tailoring the signal to suit the prescribed methods set forth by the powers that be including the likes of Dolby, DTS and THX.

By virtue of these actions would I be a condemned enthusiast guilty of audiophile blaspheme? Hardly. The signal is already corrupt from compression algorithms and home theater hardware appliances are specifically engineered for the purposes of extracting and recreating the special effects bred into the source program material. Given that the creators of the format intended it this way only strengthens my (our) allegiance to the creed.

[RebelMan]

Having been to many live musical performances over the last 25 or so years-most concerts don't have the bass subwoofers produce.

There was a similar point I attempted to make on post #23 but it seems to have been overlooked.

[dknightd]

I happily profess to using a sound processor as I see no alternatives. Besides it’s a required staple in any home theater.

I hope you have a way of bypassing the processing when listening to music!

[dknightd]

There was a similar point I attempted to make on post #23 but it seems to have been overlooked.

There are some exceptions - big organs in cathedrals, some big drums, and some electronic music. But by and large this is true, IF you cross your sub over below about 40hz. If you use the more usual 80hz value then there is significant energy in the "subwoofer" frequencies in much live music (of course then it is not being used as a subwoofer, rather as a low woofer).

If I listened to organ music I would almost certainly have a subwoofer in my system, but I listen to mostly reggae, rock, jazz, bluegrass so feel no need -
but like I said I do consider the possibility of it being useful. . .

[ZX10 Guy]

The point of this discussion revolves around subwoofers trying to produce mid-bass stereo for which they were not designed but which full-range loudspeakers were. EQ’s used in any “blending” capacity is harmful to stereo regardless of the specific instrument employed to the task, freedoms of enjoyment not withstanding.

Subwoofers are not involved in midbass. Midbass is higher up in the frequency range and by most considered anything above 100 Hz. So your blending argument with respect to subs holds zero water. If you consider the "blending" that this EQ is doing harmfull regardless of the fact that the corrections are made based on in room response, then I can't help you as you're too blinded by the whole mystical audiophile mantra that seems to be pervasive here.

The SMS-1 (specifically) is an expensive special-effects toy, period. Anyone that would invest in elaborate gimmickry rather than making the effort to implement the tried and true speaks volumes (pun) where priorities lie on high-end audio. Absolutely nothing wrong with that but if it looks like a duck, walks like and duck and quacks like a duck, then it must be a duck. LOL

And someone who is so jaded and blinded by the mystical cult of audiophile nervosa speaks volumes when he ignores the science behind how the SMS or other room measurement based EQ is used. So I guess the people at Rives Audio don't care about audio and should just give up being credible consultants for room treatment and tuning. http://www.rivesaudio.com/PARC/PARCframe.html

I would consider myself more of an audio "truist", if there were such a word, rather than purist but the latter suits me just fine. I happily profess to using a sound processor as I see no alternatives. Besides it’s a required staple in any home theater. And I freely admit to tailoring the signal to suit the prescribed methods set forth by the powers that be including the likes of Dolby, DTS and THX.

By virtue of these actions would I be a condemned enthusiast guilty of audiophile blaspheme? Hardly. The signal is already corrupt from compression algorithms and home theater hardware appliances are specifically engineered for the purposes of extracting and recreating the special effects bred into the source program material. Given that the creators of the format intended it this way only strengthens my (our) allegiance to the creed.

I say you're a hypocrite if you don't back your surround processor out of your system based on your "purist" stance saying it's ok to leave it in for your "critical" stereo listening when it's a fact your processor alters the input signal by adding it's own delay effects.

[RebelMan]

I hope you have a way of bypassing the processing when listening to music!

I do.

[RebelMan]

Subwoofers are not involved in midbass. Midbass is higher up in the frequency range and by most considered anything above 100 Hz. So your blending argument with respect to subs holds zero water. If you consider the "blending" that this EQ is doing harmfull regardless of the fact that the corrections are made based on in room response, then I can't help you as you're too blinded by the whole mystical audiophile mantra that seems to be pervasive here.

Subwoofers shouldn't be involved but often are. The entire audible band between 20Hz and 20kHz is broken down by octaves, ten to be exact. The first octave is low bass the second mid-bass and the third upper bass. The second octave (mid-bass) is recognized as stretching between 40Hz and 80/100Hz. 100+Hz is upper bass. You are welcome to free dose of mystical mantra if you are ever in the area. :rofl:

And someone who is so jaded and blinded by the mystical cult of audiophile nervosa speaks volumes when he ignores the science behind how the SMS or other room measurement based EQ is used. So I guess the people at Rives Audio don't care about audio and should just give up being credible consultants for room treatment and tuning. http://www.rivesaudio.com/PARC/PARCframe.html

They do care, in fact, they make it very clear...

Even at Rives Audio we recommend reducing any bass anomalies as much as possible before employing the PARC; the less electrical equalization the better.

Here's a thought for the technically unaware, how about no equalization for the best performance?!!! Hmm... :roll:

I say you're a hypocrite if you don't back your surround processor out of your system based on your "purist" stance saying it's ok to leave it in for your "critical" stereo listening when it's a fact your processor alters the input signal by adding it's own delay effects.

I say you are misinformed. I don't use a surround processor for stereo only home theater. :B

[hd99yr]

This comes with the understanding that a modified Honda Civic can offer great fun too but it is no McLaren F1. It's only a modified Honda Civic.

I'll take the Bugatti Veyron! Why settle for second best and not take advantage of the latest technology for the best experience available? :W

[ZX10 Guy]

They do care, in fact, they make it very clear... Here's a thought for the technically unaware, how about no equalization for the best performance?!!! Hmm... :roll:

And they make it clear that if the attempt to correct the room with treatments doesn't work, then the use of the PARC is totally acceptable. Which is what I've been saying throughout this back and forth. :roll:

I say you are misinformed. I don't use a surround processor for stereo only home theater. :B

I don't keep tabs on your system so I can only go by the bits and pieces you post up.

[hd99yr]

Subwoofers shouldn't be involved but often are. The entire audible band between 20Hz and 20kHz is broken down by octaves, ten to be exact. The first octave is low bass the second mid-bass and the third upper bass. The second octave (mid-bass) is recognized as stretching between 40Hz and 80/100Hz. 100+Hz is upper bass. You are welcome to free dose of mystical mantra if you are ever in the area.

Mid-bass
The frequency band that occurs just above the low bass region, but below the midrange. This band runs from approximately 75-150 Hertz. :rofl:

[ZX10 Guy]

Ok. Let's cut to the chase. RebelMan, have you measured your in room response in any fashion? With your purist stance how confident are you that your system is even close to producing what is recorded on those shiny little discs?

[hd99yr]

sorry, I meant 50 to 100 Hz

so just splitting hairs

[ZX10 Guy]

Subwoofers shouldn't be involved but often are. The entire audible band between 20Hz and 20kHz is broken down by octaves, ten to be exact. The first octave is low bass the second mid-bass and the third upper bass. The second octave (mid-bass) is recognized as stretching between 40Hz and 80/100Hz. 100+Hz is upper bass. You are welcome to free dose of mystical mantra if you are ever in the area.

sorry, I meant 50 to 100 Hz

so just splitting hairs

I conceed that I had a brain fart with this.

[Russ L]

On a lighter note here is a pic of the little guy...

Great pic RebelMan. Your a lucky guy! Regards, Russ

[Aussie Geoff]

Guys

Just a gentle reminder - this is a fun hobby

And a forum we all like to keep that way... :T

Geoff

[BassThatHz]

First off I would like to state my background: I write computer software and am currently working for a wireless internet service provider (also providing VOIP/IPTV); so I would say that when it comes to anything that is digital or that needs signal processing I have at least an above average knowledge of. In fact, every workday I depend entirely on my ability to think logically and apply those thoughts within reality in order to keep my job.

Quote:
Originally Posted by dknightd
I hope you have a way of bypassing the processing when listening to music!

Posted by RebelMan
I do.

What? If you’re joking then fine, but how do you suppose you are converting the binary digits on your CD to an analog voltage without using an AD converter/processor? (Unless you listen only to vinyl in stereo with no volume control!) :W

Quote:
Originally Posted by Alaric
I also believe they produce nothing but distortion

100% distortion, Really? Then why are there so many articles measuring Velodyne (and other’s) subwoofer performance with distortions of less than 4% for signals approximately under 85db?

btw, Driver Q and Filter Q are two different things, I saw a few mixing them up.

Ok first off everything is a compromise, starting with the acoustical space and microphone’s used during the recording. They all have colorations and bandwidth limitations. Secondly (assuming you use CD’s or some other digital source) the signal bandwidth is brick-wall filtered to the Nyquist frequency (22khz for CD’s) to keep out aliasing. This also applies to lossless HD even at 192khz but at some point it becomes negligible.

These compromises continue on out until the master disc is ready for the public. At which point we are all give a mostly static copy to try and reproduce.

As far as “tools” are concerned, everything mentioned here is simply a tool used to reproduce and control sound (b&w speakers included). Choosing to convert electrical energy into acoustical energy is just another form of compromise. Of course if you can find a better approach then all the power to you. After break-in everything wears out over time, it doesn't get better. :cry:

Guess what… in general the crossover’s in all speakers are analog signal processors, filtering and therefore skewing the original recording. Of course this is necessary to avoid non-pistonic movement (intermodulation) of the drivers and is yet another compromise made. This is why The Nautilus is more than 3-way and has minimalist circuits. Same goes for the DD-1812. As the piston moves further (JL gotham 4" x-max comes to mind) the distortion must increase; hence why equally big drivers always win, up to a point of course, after which the cone mass/strength becomes a problem.

Octaves and their naming conventions aside, as long as the subwoofer driver can stay pistonic within its assigned bandwidth and the crossover integrates smoothly with the main bass drivers I see no need to sentence such units capable of such. That aside, timing and placement are the two killers.

Now what if the music source signal demands your system to play a 15hz tone (regardless of reason), if you DON’T have a subwoofer or device capable of such action, how badly (distortion wise) do you think a system would respond if it can’t even hit 25hz at -3db? I don’t know but I doubt it is what the artist intended!

You can either treat the room to reduce anomalies of the reflected sound or EQ the input/output signal (or both). It is possible to apply “acoustically transparent” cloth to the entire room surface area to avoid the ugliness of treatments. If you do EQ you will affect the direct sound as well which IS worse; however it is also much easier and cheaper to do so, in most cases. EQ boost takes up dynamic head room (digital bit depth) or increases power amp/driver compression; negative EQ increases headroom for all unaffected frequencies by simply reducing or removing the affected bandwidth.

I would find it quite interesting to see the results of a few controlled blind tests, in which well tuned subwoofer'ed systems are compared to identical full range only units; just to see if a person could spot the difference and which of the two they preferred.

Perhaps if you could somehow get a bunch of nano-bots to record and reproduce accelerations and de-acceleration of air molecules in your room you could simulate a near perfect sound reproduction system; we will be some lucky if we see that in our lifetime. :T

Chaos is easy, purification takes exponentially focused energy from an external source and so the universe naturally opposes this. :roll:

[PhotoRobot]

As a gentle reminder, I can't believe the corner Rebelman has been backed into for such a great post. His initial post is a great reference for considerations in design of a stereo (2 ch) system to enjoy music as it is recorded. I didn't see one moment in his post where he said this is reference, instead, he took many factors into consideration and described his point of view from a masterful standpoint.

While I am not an audiophile to the point where vacuum or non-vacuum states with the perfect room dictate my reasoning, I can say that his post resonates with clarity, understanding -- that are the very essence of my B&W experience. I do not value unneccesary bass, bass from different manufacturers, bass not in design with the studio recording. My little 804s in 2 channel mode produce the exact sound i'm looking for.

Regardless of my limited knowledge and experience, watching these forums for years this would be one of the guys I would pay to help me design my ultimate system because we are after the same end. While we may never reach it, it is a joy to find the little cul-de-sac where clarity in reproducing something analog with digital is prevalent.

PRobot

[BassThatHz]

I don't think RebelMan intended to imply that vacuum states should dictate reasoning’s, but rather that if you could remove the room boundaries in place for a vacuum, that external influences of sounds from mother nature (thunder, earthquakes, wind etc) to the measurements being conducted against subwoofers would be minimized. He also didn’t mean that the sound would propagate through it, but that one could utilize this as an advantage to prevent that during measurements.

Anyway let's try to keep this thread focused on identifying why subwoofer’s might poorly integrate with main speakers (B&W’s to be specific). Instead of cars and wind tunnels...

[gross30]

Wow, what a great informative thread. Great responses and lots of info. Myself, I am by no means a technological "guru" when it comes to sub set ups etc. I just go with what I think sounds good, and my 801 S3 Matrix paired up with dual DD 15's keeps me smiling every time. Whether or not I need them, don't know. I just love the sound. :T

[ZX10 Guy]

As a gentle reminder, I can't believe the corner Rebelman has been backed into for such a great post. His initial post is a great reference for considerations in design of a stereo (2 ch) system to enjoy music as it is recorded. I didn't see one moment in his post where he said this is reference, instead, he took many factors into consideration and described his point of view from a masterful standpoint.

While I am not an audiophile to the point where vacuum or non-vacuum states with the perfect room dictate my reasoning, I can say that his post resonates with clarity, understanding -- that are the very essence of my B&W experience. I do not value unneccesary bass, bass from different manufacturers, bass not in design with the studio recording. My little 804s in 2 channel mode produce the exact sound i'm looking for.

Regardless of my limited knowledge and experience, watching these forums for years this would be one of the guys I would pay to help me design my ultimate system because we are after the same end. While we may never reach it, it is a joy to find the little cul-de-sac where clarity in reproducing something analog with digital is prevalent.

PRobot

Since I feel this post is indirectly directed at me, I think some words are in order here. If you look back to my original post, I took no issue with the basic premise RebelMan put up as the topic of this thread. But as we tunnelled down into the details behind why he wrote this thread there is a distinct bias that took exception to. I don't have any issues with the ideals of trying to go with a purist stance with everything. But to take things to the extreme where there is an outright bias and general dismissal of what current technology can provide to help get you closer to that audio nirvana of "being there", shows a clear agenda. The things he's said are nothing but the negatives of how a poorly setup and tuned sub will affect the ultimate sound. There was nothing about how subs can be beneficial when all the issues he points out are taken into account. I have never said a full range speaker can never provide provide proper bass reproduction, but as I've pointed out it is a challenge due to things I've pointed out in my posts. Just because I provided a counter point to his post makes me somehow the villan here. It's amazing some of the cult like followings that go on here. Because I chose to explore new ways to adjust for room issues that EVERYONE has (unless they built their house around their dedicated sound room), I've received indirect insults and statements that anyone who employs such tools don't have "real" high performance systems. I haven't made any claims about my system that I couldn't back up. In fact, I've posted my in room measurements which are backed by listening tests both by me and others to confirm that I'm on the right track. I didn't post up claims about my system's bass performance without actually measuring it. I know what my system's bass performance is...no nulls no large peaks/resonances.

I tire over what I see here as some cult like following. Hence why I don't really post up here all that often and how I now see what someone over at the AVS Forums said about why he left this forum. The blatant gang mentality that occurs when someone posts up a view non conforming to the forum's view is extremely disturbing.

[ZX10 Guy]

First off I would like to state my background: I write computer software and am currently working for a wireless internet service provider (also providing VOIP/IPTV); so I would say that when it comes to anything that is digital or that needs signal processing I have at least an above average knowledge of. In fact, every workday I depend entirely on my ability to think logically and apply those thoughts within reality in order to keep my job.

Quote:
Originally Posted by dknightd
I hope you have a way of bypassing the processing when listening to music!

Posted by RebelMan
I do.

What? If you’re joking then fine, but how do you suppose you are converting the binary digits on your CD to an analog voltage without using an AD converter/processor? (Unless you listen only to vinyl in stereo with no volume control!) :W

Quote:
Originally Posted by Alaric
I also believe they produce nothing but distortion

100% distortion, Really? Then why are there so many articles measuring Velodyne (and other’s) subwoofer performance with distortions of less than 4% for signals approximately under 85db?

btw, Driver Q and Filter Q are two different things, I saw a few mixing them up.

Ok first off everything is a compromise, starting with the acoustical space and microphone’s used during the recording. They all have colorations and bandwidth limitations. Secondly (assuming you use CD’s or some other digital source) the signal bandwidth is brick-wall filtered to the Nyquist frequency (22khz for CD’s) to keep out aliasing. This also applies to lossless HD even at 192khz but at some point it becomes negligible.

These compromises continue on out until the master disc is ready for the public. At which point we are all give a mostly static copy to try and reproduce.

As far as “tools” are concerned, everything mentioned here is simply a tool used to reproduce and control sound (b&w speakers included). Choosing to convert electrical energy into acoustical energy is just another form of compromise. Of course if you can find a better approach then all the power to you. After break-in everything wears out over time, it doesn't get better. :cry:

Guess what… in general the crossover’s in all speakers are analog signal processors, filtering and therefore skewing the original recording. Of course this is necessary to avoid non-pistonic movement (intermodulation) of the drivers and is yet another compromise made. This is why The Nautilus is more than 3-way and has minimalist circuits. Same goes for the DD-1812. As the piston moves further (JL gotham 4" x-max comes to mind) the distortion must increase; hence why equally big drivers always win, up to a point of course, after which the cone mass/strength becomes a problem.

Octaves and their naming conventions aside, as long as the subwoofer driver can stay pistonic within its assigned bandwidth and the crossover integrates smoothly with the main bass drivers I see no need to sentence such units capable of such. That aside, timing and placement are the two killers.

Now what if the music source signal demands your system to play a 15hz tone (regardless of reason), if you DON’T have a subwoofer or device capable of such action, how badly (distortion wise) do you think a system would respond if it can’t even hit 25hz at -3db? I don’t know but I doubt it is what the artist intended!

You can either treat the room to reduce anomalies of the reflected sound or EQ the input/output signal (or both). It is possible to apply “acoustically transparent” cloth to the entire room surface area to avoid the ugliness of treatments. If you do EQ you will affect the direct sound as well which IS worse; however it is also much easier and cheaper to do so, in most cases. EQ boost takes up dynamic head room (digital bit depth) or increases power amp/driver compression; negative EQ increases headroom for all unaffected frequencies by simply reducing or removing the affected bandwidth.

I would find it quite interesting to see the results of a few controlled blind tests, in which well tuned subwoofer'ed systems are compared to identical full range only units; just to see if a person could spot the difference and which of the two they preferred.

Perhaps if you could somehow get a bunch of nano-bots to record and reproduce accelerations and de-acceleration of air molecules in your room you could simulate a near perfect sound reproduction system; we will be some lucky if we see that in our lifetime. :T

Chaos is easy, purification takes exponentially focused energy from an external source and so the universe naturally opposes this. :roll:

Thank you for putting up a well balanced post.

[Kobus]

re. the cult following.

Anybody that has been around for a while, that appears to know what they are talking about and helps you out now and then will earn a great deal of respect.

In a hobby like ours it is not possible to always agree, but we must respect each others views.

Thanks to all of you for a nice read.

Kobus

ps. my question regarding the correction of some base from a point downwards, whilst the rest remains unaltered is still not answered. Should all base not be "treated" the same. For 2ch. (I am a novice in this area)

[hd99yr]

I tire over what I see here as some cult like following. Hence why I don't really post up here all that often and how I now see what someone over at the AVS Forums said about why he left this forum. The blatant gang mentality that occurs when someone posts up a view non conforming to the forum's view is extremely disturbing.

I completely agree! But please don't let the ego of the few who can't admit when they are wrong or that there are other possibilities besides theirs to address a situation in order to enhance the listening experience.

I'm sure I speak for many more than myself when I say it would be a big loss for this Forum not Having your expertise!

[ShadowZA]

Help me understand this please, and I hope that I can put my question across understandably.

First, I assume that the SMS-1 address the base from the sub only and not that of your full range mains. If I am wrong, then this post can be ignored.

Say, as an example, I set the crossover at 50 Hz. Now the base below 50 will get “modified” to suit the room and the base above that will not.

From a music perspective that can not be right or good, surely. Or am I missing something.

Am I making myself clear!

Kobus

I have an equalizer "built in" to my DD-15 sub. My operational detail could be slightly different to having a separate SMS-1. On my sub, test sweeps are produced covering its full frequency range only (say 15Hz to 200Hz). These test sweeps are used either by the equalizer to automatically "equalize" certain frequency points to "flatten" the frequency response curve as best as possible, OR you can manually adjust the equalizer sliders yourself.

Regarding crossover setup procedure sequence, I needed to do this with my DD-15:

1. Establish crossover settings for main speakers (set in processor menu)
2. Equalize sub to fit in with main speakers
3. Adjust sub crossover (in sub system settings menu)

An idea is to take a look at the Velodyne SMS-1 manual. Download it from here:

http://www.velodyne.com/velodyne/products/manuals/SMS-1%20manual_English.pdf

You can compare this to the DD subs which have the equalizer "built in". Download the manual here:

http://www.velodyne.com/velodyne/products/manuals/63-DD%20Rev%20G_%20manual_English.pdf

Hope this helps, Kobus

[Kobus]

Thanks Shadow

For 2ch, say you set the xover at 60. So overall the bass in the room below that will get "normalised" and above that not. Just sounds odd. (pun intended).

Kobus

[ShadowZA]

Thanks Shadow

For 2ch, say you set the xover at 60. So overall the bass in the room below that will get "normalised" and above that not. Just sounds odd. (pun intended).

Kobus

For 2 channel critical music listening (using the 808 as source), an analogue signal (after already being converted from digital by source) comes into my processor via the balanced analogue inputs. I have a choice as to what to do with this input. I can either send it to the "pre-amp" in which case it only passes through a volume control before being sent to power amp. Or I can "process" it in which case I can re-route it through the processor & do stuff with it - I have not experimented thus far but I'm sure that I can send it to sub & so forth.

At present I'm only sending it to mains (full-range). No sub, no equalization, no crossover.

The digital signal from the Marantz player, on the other hand is sent to the processor, converted to analogue, processed, crossed over & sent to equalized sub. This used for movies & music videos. Sub kicks in at around 60Hz & outputs an equalized sound within the frequency range 15Hz to 60Hz. Above this frequency (crossover also set at 60Hz in processor menu), the mains, centre & surrounds kick in & are unequalized. Note that the Krell has its own built in "room correction" software too. Have not experimented with it.

Bass is usually the root of all problems when it comes to sound. Either there is too much or too little & this is the reason that equalization concentration in this area is of importance.