Halo C2 Bass management

[T()()L]

Hello.

Just wondering where the bass goes if you select "no" in the set-up menu for the subwoofer,does not state anything clearly in the manual : (

Hopefully to L and R main speakers,does anyone have a clue?



Nick

[Peter Nielsen]

It goes to all speakers marked as LARGE. (If you set subwoofer to NO and all speakers to SMALL, then you have an invalid setup).

Peter

[T()()L]

Thanks Peter.

Nick

[Chetk]

It goes to all speakers marked as LARGE. (If you set subwoofer to NO and all speakers to SMALL, then you have an invalid setup).

Peter

Peter,

Is that the only difference between large and small in the settings? If I have "large" set and a subwoofer, do the lower frequencies only go to the subwoofer?

[Chris D]

Chet, that's the basic premise of the "large/small" setting in every receiver and processor. If you chose "large", the entire range of frequencies contained in a particular channel goes to that channel's speaker. If you select "small" for that channel, it will send all frequencies below a specified cutoff to the subwoofer, and leave all other sounds in the channel speaker. Typically the cutoff is 80Hz, but some processors allow you to select the cutoff, like Parasound.

For ALL speakers other than the very, very, very best and biggest (which almost none of us have) I always recommend people select "small" for all their speakers. I adhere to the basic premise that bass should be sent to the place that was designed to reproduce it, and that's the sub.

[Savannah]

but doesn't E-Bass also compensate for this by allowing you to set your speakers on Large but still send everything to the sub too?

[Peter Nielsen]

Peter,

Is that the only difference between large and small in the settings? If I have "large" set and a subwoofer, do the lower frequencies only go to the subwoofer?

The LFE audio channel always goes to the subwoofer. (If the subwoofer is disabled, LFE will go to all speakers marked as LARGE).

If you set a speaker to LARGE, then none of the sound for that speaker channel goes to the subwoofer. (Unless EBASS is enabled).

If you set a speaker to SMALL, bass below the crossover frequency for that speaker channel will go to the subwoofer.

If you enable EBASS, then all speaker channels with LARGE speakers will also go to the subwoofer.

Hope this explains it.

Peter

[Chris D]

Yes, as Peter says, ebass doubles up the bass. (if selected)

[Savannah]

how do you connect multiple subwoofers to the 7100. I know that you use a
Y cable for two but if you wanted to use more than two. Would there be a signal loss reaching each sub or any degradation in the sound. Is there any other way to connect these subs
Thanks

[Peter Nielsen]

how do you connect multiple subwoofers to the 7100. I know that you use a
Y cable for two but if you wanted to use more than two. Would there be a signal loss reaching each sub or any degradation in the sound. Is there any other way to connect these subs
Thanks

Use multipe Y cables, or a 3-tap Y cable...

It's not trivial to get multiple subs to sound good together. If your subs have level and phase adjutment controls, it will help...

Peter

[Wadsbrau]

Chris,

I have a related question if you dont mind. Kind of a what if?
In the 7100, if I have "subwoofer" set to Yes, but "sub filter" = off (because I like the xover in the sub better), how does the 7100 handle the bass management? Esp for LFE and for "small" spkrs. With this setup.

Does anyone know what the subwoofer crossover slope is for the 7100?

Thank you
Darren

[Peter Nielsen]

I have a related question if you dont mind. Kind of a what if? In the 7100, if I have "subwoofer" set to Yes, but "sub filter" = off (because I like the xover in the sub better), how does the 7100 handle the bass management? Esp for LFE and for "small" spkrs. With this setup.

The Parasound "Subwoofer filter" setting is not integrated with the bass management. It is quite simply a digital LP filter that is applied to the subwoofer output. (It is not a "smart" filter that is integrated with the bass management and redirects higher frequencies to other channels). Frequencies above the filter threshold are simply dropped when this filter is used. Of course the same happens when the subs internal filter is used, so no difference there.

The sub filter in the 7100 should be disabled if your sub has an internal LP filter, since the sub's own filter is more than likely a better match. The 7100/C1/C2 setting is there only for subs that do not have a builtin LP filter.

Does anyone know what the subwoofer crossover slope is for the 7100?

That's a good question... Might be worth calling Parasound for an answer! (My guess is that it is a pretty steep digital filter, probably 12dB/octave).

Peter

[Chetk]

This is an interesting dicussion. Thanks for the info Peter and Chris.

I have the S-150PKTHX ULTRA Self Powered System located at the top of this page. Each THX speaker is set to have their own 80Hz crossover. So, do you think it's best to set all speakers to large, set the C1 subwoofer to THX Ultra 2 and turn off EBASS? Of course, the subwoofer is set to on.

I figure, by using those settings, the speakers do all of the crossing over.

Edit: Actually, my sub is different from the one shown there. Here is my actual sub. Also, although I mentioned above that the crossover is set to 80Hz, I'm simply using the THX filter settings on the speakers. I believe that THX's crossover point is 80Hz.

[Chetk]

One last note: With all of my settings listed above, I'm still VERY unsure of when to activate THX Cinema mode on the C1. So far, I have only been activating it on THX certified movies, but I know there's a deeper meaning to this mode. I just haven't been able to understand it yet. I've even viewed the manual (granted it was long ago when I first set up my system). I will go back and brush up on my reading.

Here is what the C1 manual says about the THX modes:

THX: In modes where it is available, THX processing is controlled by the THX key on the Master remote’s
first C1/C2 page, not by the remote’s Mode keys or the SURROUND button on the C 1. The varieties of
THX processing are described below:

• THX Cinema: This is the basic THX processing mode. (To save space, it is shown only as “THX” on the
C 1’s front-panel display.) When activated from mono or stereo mode (or Direct mode, with Dolby 2/0 signals),
this processing includes only re-equalization (to compensate for differences between home and theater
acoustics, which would otherwise make movie soundtracks sound too bright) and timbre matching (to
maintain frequency balance between front and surround channels); see page 60 (or see my next post). THX processing is also
unavailable if no surround speakers are selected in “Speaker setup/Size”, except in mono and stereo modes.

• THX Surround EX: A THX-enhanced version of Dolby EX for movie soundtracks; it is available only in systems
with one or more surround back speakers in addition to L and R surround speakers. To select it,
press the THX key once or twice (depending on Setup entries and the input signal) while in Direct mode.

• THX Ultra2 Cinema: A version of THX designed for playback of 5.1-channel digital soundtracks over a 7.1-channel
system. It is engaged by pressing the THX key again while in THX Surround EX mode.

• THX MusicMode: Similar to THX Ultra2 Cinema, but for 7.1-channel listening with 5.1-channel music recordings,
which are mixed differently than movie soundtracks. With a full 7.1-channel speaker setup, it provides a
wide, stable rear soundstage, placing surround sounds to best suit music playback. It is reached by pressing
the THX key yet again while in THX Ultra2 Cinema mode.

I'm still very confused on how this corresponds to the speaker setup. :cry:

[Chetk]

Also from the C1 manual:

THX® Processing
When THX modes are selected for an incompatible source or speaker setup, the C 1 will remember the selection and will automatically apply it when the setup is changed or when a compatible source is selected.

Pressing the THX key on the Master remote turns on THX signal enhancements that work in conjunction with most of the C 1 listening modes. The exceptions are music modes that generate surround signals from two-channel source material, such as PL II Music, Neo: 6 Music, Natural, Party, Club, and Concert.

THX processing has several parts and modes:

• Re-Equalization, which is patented by Lucasfilm, adjusts the frequency response of movie soundtracks to compensate for the acoustical differences between home theaters and commercial movie theaters; without it, movie soundtracks would sound overly bright and fatiguing. It is applied to the front channels and, in THX Surround EX mode, to the surround back channels, but not to the side surrounds. Re-Equalization is not used in the THX MusicMode.

• Timbre Matching compensates for a characteristic of the human hearing that changes the apparent frequency balance for identical sounds coming from different angles and directions. Because the main speakers are at the front and surround speakers are at the sides, this hearing characteristic would make voices and other sounds change as they moved from the front to the surround channels, or vice versa. Timbre matching alters the frequency balance in the side surround channels to compensate for this.

• Adaptive Decorrelation functions with Dolby Pro Logic to add a greater sense of spaciousness and to enlarge the listening “Sweet spot.” It accomplishes this by altering the mono surround information so that the left and right surround speakers receive different, rather than identical, signals. It
does not apply when the surround channels already differ from each other, as is usually the case with such discrete digital surround systems as Dolby Digital and DTS.

• THX Surround EX decodes information for the surround back channels from signals matrixed into the surround side channels. It is not available for non-surround signals or for those which, like DTS-ES Discrete, carry back surround information as a separate digital signal. To activate THX Surround EX, press the THX key on the Master remote while in Direct mode. THX surround EX will be selected automatically if a Dolby Digital soundtrack includes the digital “flag” that identifies it as carrying this information. THX Surround EX is available only when the presence of at least one surround back speaker has been noted on the Speaker Setup/Size menu.

• Advanced Speaker Array (ASA), available only in systems with dual surround back speakers, compensates for the effect of different speaker spacings on the size of the listening “sweet spot.” When it is active, two more modes become available:

– THX Ultra2 Cinema is designed for playback of 5.1-channel digital soundtracks over a 7.1-channel system.

– THX MusicMode is similar, but sends more sound to the surround back speakers and less to the side surrounds.

• Boundary Gain Compensation reduces excessive bass below about 35 Hz, to prevent the boominess that can occur when speakers with substantial response down to 20 Hz (including subwoofers that meet THX Ultra2 standards) are used in typical-sized home listening rooms. It should be activated in setup if you have such subwoofers, but otherwise turned off.

[Chris D]

Hi, Chet, for 95% of users, (Parasound or otherwise) including you, what I recommend to people is the following: (which is also what I use)

- Set all speakers to SMALL
- Subwoofer YES
- Subwoofer filter ON
- Subwoofer freq 80Hz
- Enhanced Bass OFF

Chet, for your subwoofer specifically, sure, you can set it to the THX Ultra sub setting in the C1/C2. It's more rare that someone actually has a THX Ultra 2 sub.

As for THX processing, to be very simplistic and bottom-line it, I would say that the rule would be that you would want to select "THX Cinema" for sources/DVD's that have NOT been equalized to THX standards. If you have a DVD stamped "THX", that's pretty obvious. Otherwise, you don't really know for sure. So me personally? I just turn it on and leave it on. If I happen to notice a movie already has THX equalizing, I might turn it off. If I forget, though? It still sounds great.

[Chetk]

See my answers/questions in red in your quote below...

- Set all speakers to SMALL Why to small? My speakers have built in THX crossovers. So doesn't this mean that, if I set them to small in the C1, I would be crossing out frequencies at the C1 and then again at the crossover in the speaker?
- Subwoofer YES
- Subwoofer filter ON Again, if the subwoofer has a built-in crossover, which should I use? The one in the sub's amp or the one in the C1?
- Subwoofer freq 80Hz
- Enhanced Bass OFF

Chet, for your subwoofer specifically, sure, you can set it to the THX Ultra sub setting in the C1/C2. It's more rare that someone actually has a THX Ultra 2 sub.

As for THX processing, to be very simplistic and bottom-line it, I would say that the rule would be that you would want to select "THX Cinema" for sources/DVD's that have NOT been equalized to THX standards. If you have a DVD stamped "THX", that's pretty obvious. Otherwise, you don't really know for sure. So me personally? I just turn it on and leave it on. If I happen to notice a movie already has THX equalizing, I might turn it off. If I forget, though? It still sounds great. Actually, I'm more into hearing things the same way the audio mixer heard them when they made the mix for DVD. After reading the descriptions I posted above, it sounds like there is some post-processing done by the THX option. I'm not so certain that's a good thing. However, I can tell you that I have listened to audio with this option on and with this option off. I can't tell the difference.

[Peter Nielsen]

Chetk,

Set the speaker to LARGE if you judge that it doesn't need help by the subwoofer.

The easy choice is when your main speakers are true full range speakers, linear from 20Hz. In this case most people will want to use these speakers as LARGE, with no help from the subwoofer.

However, if you don't have mastodon speakers like this, and your mains go down to, say 35Hz ,and your other speakers to 80Hz... What to do then? Do you want to run your mains as LARGE and miss out on any frequencies below 35Hz? Or do you want to set them to SMALL and thus let the 35-80Hz range, which they are perfectly capable of, go to waste...

This is really a matter of taste. For movies, I think the better choice is to make use of the subwoofer and not use the main speakers all the way out. However, for music listening, the mains may very well sound better by themselves, despite that you don't get the really low bass...

Ask yourself this: Are your speakers capable of really low bass, or do you personally feel that you don't want the subwoofer to help. In this case, set the speaker to LARGE. Otherwise set it to small.

What is the THX crossover in your speaker? Is it an 80Hz HP filter. In this case, you definitely should set all speakers to SMALL, and set the subwoofer crossover to the THX frequency (80Hz).

You should always use the builtin subwoofer filter. ONLY use the HALO filter if your subwoofer is crippled and does not have a filter.

Peter

P.S. Rule of thumb: If you can lift your speaker off the ground without the help of a 2nd person, set it to SMALL. If you need a 2nd person to help you move the speaker, set it to LARGE. Of course this is not always true, but it's a good starting point :B

[Peter Nielsen]

Why to small? My speakers have built in THX crossovers. So doesn't this mean that, if I set them to small in the C1, I would be crossing out frequencies at the C1 and then again at the crossover in the speaker?

In a way, yes. However, you DO NOT want the crossover to happen in the speaker. When the speaker crossover (HP filter) kicks in, frequencies are lost forever. The speaker can't direct the lost frequencies to the subwoofer.

If you set the C2 speaker setting to LARGE, then the speaker's THX filter will filter out all your bass and you lose the whole 0Hz-80Hz range for that channel! Set it to SMALL, and make sure that the C2 crossover frequency is set to 80Hz. Then the speaker will get 80Hz and above. Anything below goes to the sub.

The builtin THX in your speaker is there for use with setups that don't have an advanced controller like the C2. For instance, you could have an "el cheapo" preprocessor that runs all channels to the THX subwoofer. The subwoofer crosses at 80Hz and so does the speakers. Hence, no advanced digital processing is needed. With the C2, you don't need the THX crossovers in your speakers.

Peter

[Chris D]

Basically, what Peter said. Almost NOBODY, and I mean NOBODY, has speakers that can truly produce bass all the way down to 20Hz or below. So I do recommend that everybody other than the 5 people in the USA with $70,000 speakers set them to "SMALL" in their processor. You may not be utilizing your speaker's capability to reproduce ***some*** frequencies below the crossover, (usually 80 Hz) but you'll get much better RESULTS by letting your subwoofer produce the bass. You may have heard me say this before--essentially, I hold to the premise that bass frequencies should be sent to the thing that was designed to produce bass. And that's the subwoofer. Of course, there's little "but's" when somebody says that, but I think it's a good general principle.

As to whether to let your speaker use its crossover instead of setting the speakers to "SMALL" in the processor, would your speakers be able of outputting frequencies below the crossover to a subwoofer? If not, you're just losing the bass, and it's not being played by anything at all.

[Peter Nielsen]

Basically, what Peter said. Almost NOBODY, and I mean NOBODY, has speakers that can truly produce bass all the way down to 20Hz or below. So I do recommend that everybody other than the 5 people in the USA with $70,000 speakers set them to "SMALL" in their processor.

Yes, this always holds true if all speakers are IDENTICAL.

Also, those "5 people" will still want to set the speakers to SMALL if they are identical.

The only time you really need to mess with LARGE/SMALL is when you use speakers of radically different capacity for front/center/surrounds.

If the fronts are very different from the surrounds/center, then it may not be a good idea to set all speakers to small.

For example, my fronts go down to 22Hz, my surrounds to 34Hz and my center to 80Hz. When I was using the C2, I had my fronts set to LARGE and my center/surrounds set to small. Obviously I was never using the 34Hz-80Hz range of my surrounds, but it was still better than losing anything below 34Hz...

That said, if I had a set of five identical Magnepan 20.1s, I would set them all to SMALL and set the subwoofer crossover to 25Hz :B

Peter

[Chris D]

Good point, Peter. That's another way to skin the cat!

[Chetk]

Thanks for your replies guys. I would have replied sooner, but, for some reason, I'm not getting an e-mail notification every time someone else replies on this thread (even though I am subscribed to it). The only e-mail notification I received was from Chris' post above mine.

Nevertheless, I am so scared of setting my speakers to "small". I don't know why, but just the label of "small" makes me feel like I'll be missing out on something. I think I'm going to print out Peter's and Chris' explanations since my last post and go home and play.

• If I set the speakers to "small" in the C1, should I turn off the THX crossover in the five speakers?

I'm still really confused, but I promise to read through the above info and try to make sense of it. I'm really slow. :?? :blink: :duh: :banghead: :crazy: :scratchhead: :gah:

[Chris D]

If it makes you feel any better, Chet, I have NEVER used the "large" setting in any receiver or processor I've ever had.

Yes, I'd turn off the crossover in the speakers themselves.

[Peter Nielsen]

Nevertheless, I am so scared of setting my speakers to "small".

Think of it like this:

LARGE = Full range speaker: Does it all - needs no subwoofer help to reproduce lower frequencies (down to 20Hz and below).
SMALL = Normal speaker: Needs some subwoofer help to reproduce the lower frequencies.

Try this: Hook up two of the speakers to your left and right channels. Don't connect anything else. No subwoofer, no other speakers. Set the bass and treble controls to 0dB.

Are you happy with the bass playing from the two speakers only? Is the sound "heavy" enough for your taste? If indeed it is, then by all means set the speakers to large! :B

However, if you feel that the speakers could use some help from the subwoofer, set them to small. In the end, that's what it's all about...

If I set the speakers to "small" in the C1, should I turn off the THX crossover in the five speakers?

Yes, definitely! Those THX "crossovers" are probably passive HP filters. They will degrade the sound to some extent. If you can disable them, it's a VERY GOOD thing. An active crossover (as done by the C2) is MUCH better.

If you set the speakers to LARGE in the C2, then you MUST disable the crossovers in the speakers! Otherwise you have an obvious configuration error. A full range (LARGE) speaker is not supposed to filter anything out!!!

So no matter how you turn it, those speaker filters need to be disabled! :T

Peter

P.S. It sounds like this is a clear case: Your speakers are 80Hz THX standard speakers. The passive THX filter in the speaker should be disabled and the active THX filter in the C2 should be used instead. Make sure that the speakers are set to SMALL and make sure that the C2 subwoofer crossover is set to THX (=80Hz). Either use the C2 subwoofer filter (set to 80Hz) or use the filter in the subwoofer. You must use one. You must not use both. Either setting will work, but a listening test is best. If you can't hear a differece, disabling the filter in the subwoofer and using the C2 filter is a good choice.

[Chetk]

OK, I did these changes last night, but everybody else in the house was asleep so I couldn't crank it and listen to the difference. I'll try it tonight and see what I think.

However, I want to address this statement:

Those THX "crossovers" are probably passive HP filters. They will degrade the sound to some extent. If you can disable them, it's a VERY GOOD thing. An active crossover (as done by the C2) is MUCH better.

Here's what the M&K web site says about the "crossovers" in my 150P's:

M&K ACTIVE PHASE-FOCUSED CROSSOVER

M&K's exclusive Active Phase-Focused crossover, developed specifically for this speaker, further improves its performance by also optimizing more than just the speaker's on-axis response to give a very smooth response over a wide horizontal and vertical listening window.

While other crossover designers consider just frequency response on one axis (the sweet spot), we consider the speaker's response in both the time and frequency domains, at a very wide range of angles in both the vertical and horizontal planes-thus optimizing the speaker's three-dimensional response and improving its on-axis sound. This uniquely sophisticated crossover is critically tuned through both psychoacoustic listening analysis and complex computer analysis.

The benefits of the Active Phase-Focused Crossover are particularly important for multichannel playback systems, where listeners may not always be directly on the main axis of a given speaker. Our design means that regardless of where the speaker is located in the room, listeners will hear superior imaging and sound quality, with remarkable clarity both on and off axis.

After reading that, do you still think the crossover in the C1 would be better than "M&K's exclusive Active Phase-Focused crossover, developed specifically for this speaker"?

[Peter Nielsen]

After reading that, do you still think the crossover in the C1 would be better than "M&K's exclusive Active Phase-Focused crossover, developed specifically for this speaker"?

I am assuming this is the speaker you have: http://www.mksound.com/s150Pthx.htm

In order to use the speaker's THX 80Hz HP filter (crossover), you need to get a preprocessor that mixes and directs all 7 channels unmodified to the subwoofer. Then the speakers' 80Hz HP filter and the subwoofer's 80Hz LP will form the crossover and the preprocessor can be a "dumb" preprocessor that does not need to process the audio in any way. (Very convenient, indeed if you don't own a fancy processor like the C1).

However, the C1 cannot mix and direct all channels to the sub, so you don't have that option. Instead, you're supposed to direct the C1 to send frequencies below 80Hz to the sub and above 80Hz to the speakers. This is done as mentioned below.

See page 14 in the M&K S-150P manual that clearly tells to disable the crossover:

"D) 80 Hz High-Pass Filter In / Out - When this switch is in the IN position, an 12dB per octave 80 Hz High-Pass Filter is placed in line on the input stage of the monitor. This switch should be in the OUT position when used with any bass-management controller, such as an LFE-3, 4 or 5, or any other [consumer] processor that has internal 80 Hz High-Pass filters."

Thus, you should leave the switch in the OUT position. Set the C1 to SMALL (since these are "small" speakers; 80Hz and up). Set the C1 crossover to 80Hz THX.

Then let's move on to your subwoofer. Page 6 in the manual:

When using the subwoofer with a THX controller, set this switch to the "THX MODE" position. When
using the subwoofer with a standard stereo system or a surround sound processor that is not THXcertified,
set this switch to either "80 Hz 24 dB/OCTAVE" or the "VARIABLE" (center) position.The THX mode bypasses the internal crossover of the subwoofer.

Consequently, disable the LP filter in the subwoofer by setting it to THX as mentioned. Then set the C1 subwoofer filter to 80Hz.

Voilà! Very straightforward...

Peter

[Chetk]

You're the man Peter! I do indeed have the 150P's.

I have been running the speakers WRONG for years! I am now confident that I understand what you're saying. Thank you for being patient with me and taking the time to look at my speakers/configuration.

What's funny is that I did read these manuals when I first bought them and the C1, but I didn't comprehend everything and this, what I would call mislabeling, of "large" and "small" really confused me. I actually reprinted the 150P manual today before you posted this. The C1 manual does a horrible job of explaining what "large" and "small" means. Just out of curiosity, how did you find out about what it really meant? Years ago, I e-mail Richard of Parasound, but his explanation was very over-simplified.

[Peter Nielsen]

The C1 manual does a horrible job of explaining what "large" and "small" means. Just out of curiosity, how did you find out about what it really meant?

I agree, those labels are not very good. IMHO "full range" (instead of large) and "sub x-over" (instead of small) would be better labels....

I think I found it out by reading the manual. It is all there, although it might be a bit tricky to understand.

Peter

[Chetk]

“Small” speakers are those with limited bass capacity; to avoid distortion, the C 1 diverts bass signals from any channels with “Small” speakers and sends them to the subwoofer; this diversion takes place at the frequency set on the “Size setup” menu (In my case, the THX standard of 80Hz.). The bass from “Large” speakers, which can handle it well, is not normally sent to the sub. If you’re not sure if you should classify your speakers as “Small” or “Large,” try both settings and see which sounds best.

I guess it was that last sentence of "try both settings" that really confused me. By that description, it is also difficult to tell that the subwoofer channel will be deprived of the lower frequencies that are getting sent to the other speakers that are set to "large".

This has been a VERY informative and useful thread. I enjoyed the discussion very much.

[Peter Nielsen]

I guess it was that last sentence of "try both settings" that really confused me.

Yeah, that very sentence is not very professional. Parasound could certainly have tried to put some more effort on explaining what a "large" and "small" speaker is, instead of telling the customer to BLINDLY try it (without even explaining what to listen for).

Peter

[Chris D]

Great, chet! Another happy club member! :banana:

[Chetk]

OK, after setting up everything as explained here and really getting a chance to sit down and listen, the main "small" speakers sound great.

However, now I'm faced with a different dilemma. I am not getting much bass from my subwoofer. I have no idea what to set other settings to now. Here are the settings I need help with:

• Audio Setup > LFE Level
  Is 0db going to give me the most volume? Anything other than 0db turns into negative db's.
  
• Speaker Setup > Size Setup > Subwoofer Filter
  Should this be set to "on" or "off"? I'm trying to figure out if this is telling me that the C1 subwoofer filter is on or off, or if it's asking me if my subwoofer's filter is on or off. Two different things.
  
• THX Audio setup > Bass limiter setup > Bass limiter
  Should this be on or off?
  if on...
  
• THX Audio setup > Bass limiter setup > Limiter level
  It's currently set to -50db.
  
• THX Audio setup > Bass limiter setup > Limiter noise
  I'm assuming this is pink noise sent to the sub for calibration purposes (perhaps for setting the limiter level.)
  
• THX Audio setup > Boundary Gain comp. > THX Ultra2 Sub
  I'm not sure what exactly this allows and doesn't allow and why. I know I can set the Boundary Gain Comp on or off if I turn on THX Ultra2 Sub., but I don't even know what that means.

Anyway, I just want to make sure I'm getting reference volume levels from my subwoofer, I'm not losing any frequencies (I would like the full range you know ), and that I'm not sending any damaging frequencies to the sub.

Also note that after I post this, I'm headed straight to the C1 manual to find the answers to those features I posted here, but I just wanted to see if you guys had anything to say about them.

[Chetk]

One last thing, if I happen to get all of this set up properly and I get my levels set to "reference", what is the proper method for getting more from the subwoofer? Is it by simply going to Speaker Setup > Level Setup and increasing the db level of the subwoofer?

[Chetk]

OK, I've read the manual and found some answers. See them below in red.

• Audio Setup > LFE Level
  Is 0db going to give me the most volume? Anything other than 0db turns into negative db's. After reading the manual, I think I should leave this at 0db. Can anyone confirm this?
  
• Speaker Setup > Size Setup > Subwoofer Filter
  Should this be set to "on" or "off"? I'm trying to figure out if this is telling me that the C1 subwoofer filter is on or off, or if it's asking me if my subwoofer's filter is on or off. Two different things. It looks like the on/off indicates whether the C1 is doing the filtering. Since I want the C1 to do the filtering and NOT the subwoofer, I'll turn this to "on" and leave the frequency at 80Hz (the THX standard.)
  
• THX Audio setup > Bass limiter setup > Bass limiter
  Should this be on or off? I'm turning this off. I don't want to limit bass as my subwoofer can handle a LOT without distorting.
  if on...
  
• THX Audio setup > Bass limiter setup > Limiter level
  It's currently set to -50db. This one no longer matters because I'm turning Bass limiting off.
  
• THX Audio setup > Bass limiter setup > Limiter noise
  I'm assuming this is pink noise sent to the sub for calibration purposes (perhaps for setting the limiter level.) Eh. I don't need to know this anymore.
  
• THX Audio setup > Boundary Gain comp. > THX Ultra2 Sub
  I'm not sure what exactly this allows and doesn't allow and why. I know I can set the Boundary Gain Comp on or off if I turn on THX Ultra2 Sub., but I don't even know what that means. I have decided NOT to set this to "on." My subwoofer doesn't have this "feature."

It looks like I've answered all of my own questions. I still would like to know the most "proper" way to get more boom from my subwoofer. Should I increase the db level under Speaker Setup > Level Setup or would you recommend turning up the Bass under Audio Setup > Tone Controls?

Oh, and thanks for letting me think out loud.

[blownrx7]

Chet,
I agree with all your findings but I still question what the "THX Ulktra2 Sub"
I don't know any subs that mention this feature so I'm baffled as to what it does.

THX Audio setup > Boundary Gain comp. > THX Ultra2 Sub
I'm not sure what exactly this allows and doesn't allow and why. I know I can set the Boundary Gain Comp on or off if I turn on THX Ultra2 Sub., but I don't even know what that means. I have decided NOT to set this to "on." My subwoofer doesn't have this "feature."

[Chetk]

blownrx7,

I read in the C1 manual that this Boundary Gain comp. feature is supposed to keep your subwoofer from being too "boomy." Here's the exact explaination:

Boundary gain comp. (compensation) tames the excessive, boomy bass that can occur when listeners are near the back wall of home theaters whose subwoofers meet THX Ultra2 standards or have flat anechoic response down to 20 Hz. If you have such a subwoofer, setting THX Ultra2 Sub to “Yes” gives you the option of turning this feature on or off (try listening to it both ways, to see which gives you more lifelike bass). If your subwoofer does not meet these standards, setting THX Ultra2 Sub to “No” will disable boundary gain compensation.

[Peter Nielsen]

It looks like I've answered all of my own questions. I still would like to know the most "proper" way to get more boom from my subwoofer. Should I increase the db level under Speaker Setup > Level Setup or would you recommend turning up the Bass under Audio Setup > Tone Controls?.

There is a difference between the two. Turning up the bass will also (slightly) affect the lower frequencies of your 150s. If you just want more sound level from your subwoofer, then the proper thing to do is to adjust the level.

How did you set the subwoofer level in the first place? Did you use the C1 autocalibrate?

Peter

[Chetk]

How did you set the subwoofer level in the first place? Did you use the C1 autocalibrate?

I did an autocalibrate with the C1 microphone. However, when I do that EVERY single speaker ends up with negative db numbers. Something like this:

• Left -2.0dB
• Center -1.5dB
• Right -2.0dB
• Right surround -3.0dB
• Right back None
• Left Back None
• Left surround -2.5dB
• Subwoofer -3.5dB

So I actually increase each one by 1.5dB's to kind of "zero" everything out. Like this:

• Left -0.5dB
• Center 0dB
• Right -0.5dB
• Right surround -1.5dB
• Right back None
• Left Back None
• Left surround -1.0dB
• Subwoofer -2.0dB

However, since I don't feel I'm still getting enough action from the subwoofer, I sometimes feel I have to crank it up to about 4.0dB or higher. :E

[Chris D]

Chet, you can see my thread about my Parasound setup files, including where I talk about my calibration settings. For me too, every speaker ends up with a negative value. (I have very efficient speakers with Klipsch) Realize that this by itself doesn't mean anything--channels could be positive, negative, or zero.

When you calibrate, you're not calibrating to have any particular channel set at 0. (other brands and products do this sometimes, if there are no units with the volume) Parasound and other brands, though, have units displayed with the volume, so that a high or max volume setting is "0 db" and as you turn down the volume, it shows negative db values. So with Parasound (and these other brands) you calibrate your speakers so that a test tone at your volume setting of "0 db" produces a THX reference volume from a channel--75 db measured on a SPL meter.

The Halo autocalibration feature does this for you automatically, so that once calibrated, if you watch a movie with the volume at 0 db, you're listening to it as the film studio intended; at that volume. There is no need to bump up all speakers levels afterwards. Specifically with your subwoofer, depending on how it performs in your system, you may like to bump up the sub level or turn it down. Having your sub EQ'd with something like a BFD will help smooth out the sub performance.

(note: after a system is calibrated, most people actually find listening to movies and music at THX reference levels to be too loud. I myself usually use my system at maybe -15db total volume level, but even though the overall volume is lower, the individual channels relative to each other remain approximately the same, and the system remains approximately calibrated)

[Chetk]

Chris, I fully understand what you're saying. After I do the autocalibration, if I don't adjust any individual speakers, I can only watch it at about -15dB's too. Of course, this depends on the source material. I've noticed that I can watch Blu-Ray DD 650Kbps tracks at around -7dB's. The volume needs to be higher for Blu-Ray than it does for the old DTS or DD tracks found on DVDs.

However, I also noticed that if I "zero" out the level settings (as explained in my last post), the main speakers seem more crisp. For me, it's a matter of increasing the amount of audio to each speaker, but running the main level a little lower. I suppose it's just a matter of preference, as to how these levels are set up.

So, this brings up my next question. Is it WAY outside of the ordinary to increase the subwoofer level by 4 or 5 dB's?

[Peter Nielsen]

So, this brings up my next question. Is it WAY outside of the ordinary to increase the subwoofer level by 4 or 5 dB's?

I don't consider it out of the ordinary. However, it is possible that your subwoofer is out of phase. Getting it into phase might solve the level issue.

AFAIK, the C1 cannot do phase adjustment. Does your subwoofer let you adjust the phase? If not, then any phase issue might have to be solved by relocating the sub, or getting a digital processor (Behringer) to fix it. I think Chris is using a Behringer, so he can probably better help you in this area...

Peter

[Chris D]

Yes... but most subs have at least a 180 degree phase switch on the back.

Chet, it sounds like you could use a full A/V system calibration. Do you have any setup and calibration discs, such as Avia or Video Essentials? These discs are fantastic for walking you step by step through full setup of your system, calibrating each channel for level, distance, and phase. Then it fully calibrates your video system, too, using specific criteria and test tones, to get it looking and sounding much better than any of us can get it just by eye and ear.

[Chetk]

I don't consider it out of the ordinary. However, it is possible that your subwoofer is out of phase. Getting it into phase might solve the level issue. Does your subwoofer let you adjust the phase?

Yes, Peter. The subwoofer has a phase switch and I have made certain it is in phase.

Chet, it sounds like you could use a full A/V system calibration. Do you have any setup and calibration discs, such as Avia or Video Essentials? These discs are fantastic for walking you step by step through full setup of your system, calibrating each channel for level, distance, and phase. Then it fully calibrates your video system, too, using specific criteria and test tones, to get it looking and sounding much better than any of us can get it just by eye and ear.

Chris, I have DVE and my TV is calibrated as well as it could be with my level of knowledge and equipment. I have, cleaned the lenses, got rid of red push, installed Duvetyne, and adjusted convergence, sharpness, brightness, contrast and color on my Mits RPTV. I'm good on the video side.

As far as audio, I have always used the mic autocalibration from the C1 and made sure that my sub was in phase.

[Peter Nielsen]

Yes, Peter. The subwoofer has a phase switch and I have made certain it is in phase.

Did you measure it, or how did you make sure it's in phase? (My Martin Logans have switches for 0, 90, 180, and 270 degrees phase. However, I let the preprocessor & software do the work to calculate the correct phase adjustment :B )

Peter