How much bass is best for a center channel: 2-way or 3-way?

[kgveteran]

What did you say :B Alright...My sound is calibrated by Audyssey.I'm thinking 0dbMV is 75db. It really isn't uncomfortable to listen in my room at these levels.I am always asking company after a movie if they felt that the sound was shreaky,too loud,distorted in anyway.They alway say how clean and clear it sounds, and never too loud.

I think a well treated room will allow you to listen at these levels also.

As to my personal fantasy of 15's flanking a Nat P...nutz to you all. One of you eggheads will design a XO for it too.You know you will.

I don't know how good I have it sometimes.Listening to "Iron Man" at 0dbMV with no hint of stress to the system is wonderful.Never reaching for the remote during dynamic scenes "Priceless".

Back to OP, threeway

[kgveteran]

Yeah, if kgveteran is distorting them, I wonder if he's listening louder than what might be healthy.

kgveteran-
Presumably, you were in the military. What did you do? I know a veteran who was an artillery guy. After firing shells for 8 years, he can barely hear anything. If you don't have any hearing loss, you might want to turn things down. Otherwise you may end up with hearing loss. Then again, 0 db could be a meaningless number if it's not calibrated to a true 0 db (which is, what, something like 85 db?). You could actually be listening at 70 db or 90 db or anything in between.

I was an M88 operator, "The Hook". I cross trained in repairs to the M-1 Abrams from the old M-60's. The M88 had a V-12 twin Turbo (continental). 33mph down hill, and at 60tons it had a damn smooth ride.

[jquin]

Heck, I don’t know. That’s why I asked the original question: How much bass should we design into a center channel? If you’re right, then we want center channels that are run full range and can play down to ~30 or 40 Hz. But most people run them with a sub. In which case there’s no major need to design them for ~30 hz output. I guess. Not sure, though. Hence this thread. (And hey, what’s the latest with your M8ta’s?)

My M8ta's have stalled a bit due to family commitments. (The kids have been driving me so mad, the family was thinking of having me committed)
I finished one, but then ThomasW said it was broken, *sniff*. I've done a quick fix on it but haven't had the time to test it, or progress the other one.
I will probably soon retrofit one of my Modula MT's with a SS6600. It will eventually become my center. I'm not sure about the RS28 that is currently in the Modula MT, I might have one of the busted ones.

I haven't gotten around to doing any distortion tests yet. I haven't seen a real detailed description yet of how it's done. It another one of those lots of assumed knowledge things. Probably because newbie don't typically do distortion tests.

Anyhow I'm more interested in whether a sub is needed at all in a surround system. I want to measure the LFE channel and see how low it goes. Hmmm I might try that. I'm currently without my Shiva driver and want to see if it is worth rebuilding.

[JonW]

I was an M88 operator, "The Hook". I cross trained in repairs to the M-1 Abrams from the old M-60's. The M88 had a V-12 twin Turbo (continental). 33mph down hill, and at 60tons it had a damn smooth ride.

So are they loud? :W

I've never seen those machines up close while running. Must be cool.

What did you say :B

:lol: :

Alright...My sound is calibrated by Audyssey.I'm thinking 0dbMV is 75db. It really isn't uncomfortable to listen in my room at these levels.I am always asking company after a movie if they felt that the sound was shreaky,too loud,distorted in anyway.They alway say how clean and clear it sounds, and never too loud.

I think a well treated room will allow you to listen at these levels also.

As to my personal fantasy of 15's flanking a Nat P...nutz to you all. One of you eggheads will design a XO for it too.You know you will.

I don't know how good I have it sometimes.Listening to "Iron Man" at 0dbMV with no hint of stress to the system is wonderful.Never reaching for the remote during dynamic scenes "Priceless".

Back to OP, threeway

Oh OK. If it's only 75 db you're probably fine. And like you say, if the room is treated, that absorbs some sound and makes you turn up the volume a bit. So it sounds like you're good. :T

[JonW]

My M8ta's have stalled a bit due to family commitments. (The kids have been driving me so mad, the family was thinking of having me committed)
I finished one, but then ThomasW said it was broken, *sniff*. I've done a quick fix on it but haven't had the time to test it, or progress the other one.
I will probably soon retrofit one of my Modula MT's with a SS6600. It will eventually become my center. I'm not sure about the RS28 that is currently in the Modula MT, I might have one of the busted ones.

I haven't gotten around to doing any distortion tests yet. I haven't seen a real detailed description yet of how it's done. It another one of those lots of assumed knowledge things. Probably because newbie don't typically do distortion tests.

Anyhow I'm more interested in whether a sub is needed at all in a surround system. I want to measure the LFE channel and see how low it goes. Hmmm I might try that. I'm currently without my Shiva driver and want to see if it is worth rebuilding.

Sorry to hear about the delays. But I totally understand. My recently finished MT project took 1.5+ years. 8O Work kind of got in the way pretty often.

For what it's worth, I'm not sure distortion tests are something you can do unless you invest in a decent measurement setup. I've got a microphone and a few other little things like LspCAD but cannot measure distortion.

Could the SS 6600 really be a drop-in replacement for the RS28 in the Modula MT? My guess is no, but I haven't looked into it carefully. My new MT uses the 6600 and I can tell you that it's great. As is the SS 18W/8531 that went along with it. A really, really nice combo. :B

[jquin]

Sorry to hear about the delays. But I totally understand. My recently finished MT project took 1.5+ years. 8O Work kind of got in the way pretty often.

For what it's worth, I'm not sure distortion tests are something you can do unless you invest in a decent measurement setup. I've got a microphone and a few other little things like LspCAD but cannot measure distortion.

Could the SS 6600 really be a drop-in replacement for the RS28 in the Modula MT? My guess is no, but I haven't looked into it carefully. My new MT uses the 6600 and I can tell you that it's great. As is the SS 18W/8531 that went along with it. A really, really nice combo. :B

Jon Marsh seems to think it will go ok as a substitue, so I'm happy.
As far as distortion tests I dont see whats hard apart from a notch filter if it is used.

[JonW]

If you've got the Jon Marsh seal of approval on the 6600, you're good to go. :T In which case I bet you like it. It's very nice.

I have no idea how to take distortion measurements. I thought you needed some fancy gear and software setup. Maybe not. I've kind of been trying not to learn about it. Otherwise I can see myself sliding down the slippery slope of buying and testing lots of drivers to try and find the ones I like best for any given project. And then I might turn into one of those crazy people who test lots of drivers. Scary stuff. So I'm trying to stay ignorant here. :W :B

[chasw98]

Otherwise I can see myself sliding down the slippery slope of buying and testing lots of drivers to try and find the ones I like best for any given project. And then I might turn into one of those crazy people who test lots of drivers. Scary stuff. So I'm trying to stay ignorant here. :W :B

Wuss!

[jquin]

Well I am surprised. :E :E :E :E :E
I have been tinkering with things for a bit now changing Lpads and the like but last night I made a change that had far more effect that I expected.
I upgraded my Modula MT to have a 6600 so for the first time I had both front speakers with 6600.
So one speaker is an M8ta and the other the Modula MT.
It was very surprising how much better it sounded. I have heard that it is worth while upgrading to a HQ tweeter but I was expecting only a marginal improvement.
Nope not marginal. Everything seems balanced and listening fatigue had almost disappeared.
I think there is still plenty of linear distortion in my system but I think I reduced the non-linear and made things better.
Looks like it's true what they say about making sure the center is matched to the mains. :T

[Hdale85]

So you redesigned the crossover for it? I don't recall John ever posting a Modula Mt crossover with the 6600.

[---k---]

Dougie:

Jon Marsh seems to think it will go ok as a substitue, so I'm happy.

[Hdale85]

Ah awesome

[kgveteran]

So, last but not least. Build a center and mains that reproduce low enough frequencies so your options are open with respect to XO to the sub. Nuf said

[JonW]

Well I am surprised. :E :E :E :E :E
I have been tinkering with things for a bit now changing Lpads and the like but last night I made a change that had far more effect that I expected.
I upgraded my Modula MT to have a 6600 so for the first time I had both front speakers with 6600.
So one speaker is an M8ta and the other the Modula MT.
It was very surprising how much better it sounded. I have heard that it is worth while upgrading to a HQ tweeter but I was expecting only a marginal improvement.
Nope not marginal. Everything seems balanced and listening fatigue had almost disappeared.
I think there is still plenty of linear distortion in my system but I think I reduced the non-linear and made things better.
Looks like it's true what they say about making sure the center is matched to the mains. :T

That's excellent. :T :B Glad you like the upgrade.

I must admit that I would not have guessed the 6600 (or any other tweeter) to be a drop-in replacement in the Modula MT. Although I have built a pair, I have not looked at the design carefully enough to see, recently. But it doesn't matter. If you say it's better, that's all that counts.

So now how about upgrading that woofer... :W

Wuss!

Who you callin' wuss, wuss? : :W

So, last but not least. Build a center and mains that reproduce low enough frequencies so your options are open with respect to XO to the sub. Nuf said

Yup. That's the plan. I was just trying to get some specifics for what "enough" is. Although with this crowd i know that there's no such thing as "enough."

[kgveteran]

Yup. That's the plan. I was just trying to get some specifics for what "enough" is. Although with this crowd i know that there's no such thing as "enough."

I think alot of the emphissis we strive for is related to headroom. 90% of the time an upgrade is needed because the builders' needs have changed in regards to SPL at the listening position. There is nothing worse than finishing a build and not being able to get the right SPL at the listening position. All the designs here will satisfy as far as SQ. Now if that sound quality can remain the same at the listening position in regards to SPL, then you won. My upgrades were always related to getting a balanced sound at the listening position.

Since my receiver is calibrated at 75db/MV0bd then listening at 0db is easy and comfortable for the viewers. There is tons of headroom, which eliminates the volume up and down during demanding scenes, which is a mood breaker during a show.

A friend at work was saying to me that he had to adjust his sub level during Iron Man repeatidly. Thats what i've eliminated with having enough headroom. All this advice will begin to build a check list of sorts for you. Once you begin to hear the same advice over and over you know that you've hit on most of the issues. Then you can take a look at your needs and sound requirements and see if the build suits your them.

It would be really helpful to get a listen to someone's system in your area to hear what all this stuff means to you in person.

KG

[jquin]

That's excellent. :T :B Glad you like the upgrade.

I must admit that I would not have guessed the 6600 (or any other tweeter) to be a drop-in replacement in the Modula MT. Although I have built a pair, I have not looked at the design carefully enough to see, recently. But it doesn't matter. If you say it's better, that's all that counts.

So now how about upgrading that woofer... :W

Well now let me temper some comments made about the 6600 being a drop in replacement.

I don't want to mis-quote Jon M.

I don't believe the idea for using the 6600 came from myself alone.
I believe that it was put forward in a post as one of a number of possible replacements for the RS28A.
I have looked for this original post but have not been able to find it as yet.

I do have a personal email from Jon Marsh that says out of all the current xo designs for the M8ta the RS28 one matches the 6600 the best.

That said I like the sound of the 6600 much better than the RS28 in the Modula MT.

I think it may be largely due to a strong preference for soft dome tweeters. Either that or the RS28's I had are poor examples of the RS28.

As far as upgrading the woofer are concerned. Jon said that he prefered the RS225 to the seas W22.
I've very happy with the RS225. The mid/bass in both the Modula MT and M8ta seem wonderful with the Daytons.
I see no reason to upgrade, esp when value for money is bought into the equation.

[JonW]

I think alot of the emphissis we strive for is related to headroom. 90% of the time an upgrade is needed because the builders' needs have changed in regards to SPL at the listening position. There is nothing worse than finishing a build and not being able to get the right SPL at the listening position. All the designs here will satisfy as far as SQ. Now if that sound quality can remain the same at the listening position in regards to SPL, then you won. My upgrades were always related to getting a balanced sound at the listening position.

Since my receiver is calibrated at 75db/MV0bd then listening at 0db is easy and comfortable for the viewers. There is tons of headroom, which eliminates the volume up and down during demanding scenes, which is a mood breaker during a show.

A friend at work was saying to me that he had to adjust his sub level during Iron Man repeatidly. Thats what i've eliminated with having enough headroom. All this advice will begin to build a check list of sorts for you. Once you begin to hear the same advice over and over you know that you've hit on most of the issues. Then you can take a look at your needs and sound requirements and see if the build suits your them.

It would be really helpful to get a listen to someone's system in your area to hear what all this stuff means to you in person.

KG-

I totally understand where you're coming from. But it's interestingly different than where I'm at. You want lots of output/SPL. And I'm after clarity. Having things really crisp and precise. Of course, both things are related. But I think it's interesting how we are all sometimes after different things from a speaker. That's got to be at least part of why there are so many different design approaches out there.

Well now let me temper some comments made about the 6600 being a drop in replacement.

I don't want to mis-quote Jon M.

I don't believe the idea for using the 6600 came from myself alone.
I believe that it was put forward in a post as one of a number of possible replacements for the RS28A.
I have looked for this original post but have not been able to find it as yet.

I do have a personal email from Jon Marsh that says out of all the current xo designs for the M8ta the RS28 one matches the 6600 the best.

That said I like the sound of the 6600 much better than the RS28 in the Modula MT.

I think it may be largely due to a strong preference for soft dome tweeters. Either that or the RS28's I had are poor examples of the RS28.

As far as upgrading the woofer are concerned. Jon said that he prefered the RS225 to the seas W22.
I've very happy with the RS225. The mid/bass in both the Modula MT and M8ta seem wonderful with the Daytons.
I see no reason to upgrade, esp when value for money is bought into the equation.

Got it. I'm glad to hear that you're happy with the 6600. I certainly like mine a lot as well. I've got 2 speakers in the house- my regular RS28 Modula MT's and my Scanspeak 6600/18W design. I haven't put the 6600 in the Modula MT's and I probably won't bother. I do really like the 6600 mated with the 18W. Of course the 2 speakers have very different designs. But my guess is that you might notice an equally large difference when stepping up from an RS180 to an 18W. Which is not to say that you should swap the RS180 and 18W in the Modula MT. Just speaking in general, I think there is a big improvement to also be had in the woofers. But once you mention "value" Scanspeaks usually drop out of the conversation. They're pretty expensive.

[kgveteran]

And I'm after clarity. Having things really crisp and precise 

Thats the best byproduct of headroom, linearity within it's it's bandwidth! If that bandwidth is 100hz-14khz, so be it, it's linearity all the way.

Most people visiting are suprised at how cleanly these HT Guide designs play at highish levels (75-90db). I know high SPL's have a bad rap, but if the headroom is there....use it!! It's when distortion creeps in that high SPL sounds bad.

I think there's a guy in this forum who has twelve(12) drivers in his IB....sounds like headroom to me :T

[---k---]

KG, I agree with you. But, when you hear the Scanspeak drivers, you're eyes will be open even further. Someday, I would like to hear a well executed WMTMW with all Scan drivers!

[kgveteran]

KG, I agree with you. But, when you hear the Scanspeak drivers, you're eyes will be open even further. Someday, I would like to hear a well executed WMTMW with all Scan drivers!

I know it's hard to put into words, but what would the improvement be with a scanspeak system ?

Sorry about the hitchhike. Kg

[JonW]

kg,

I agree that more headroom is a good thing and that it will help clarity. But I’m with Ryan here. Headroom, alone, will not get all the clarity that, at least for me, is so important. To my ears there’s a big difference in the clarity of my Dayton RS28/RS180 (Modula MT) versus my Scanspeak 6600/18W. Both are MT designs of about the same size. So the headroom is likely to be similar. But I think that the clarity is not similar. I don’t know if others would agree. We may find out soon in Iowa. Ryan is the only other one to have heard the Scanspeak MT.

How to describe the difference? Idunno… I’ll try: Clearer, more precise. Definitely more airiness. No veil covering things up. Relatively speaking, the Dayton MT sounds muddier. You know, the typical audiophile babble. But it seems like a significant difference to me. Ask Ryan. He’s less biased about it than I am. I have too much wrapped up in the design of that speaker to be objective, although I do try.

Someday, I would like to hear a well executed WMTMW with all Scan drivers!

Me too. I’ve got 3 future speaker designs I’m kicking around in my head. All use some or all Scanspeak drivers. One is a WTMW center channel and another is an all-out 3-way (regular, not center channel) in a TMWW configuration.

[---k---]

I know it's hard to put into words, but what would the improvement be with a scanspeak system ?
Kg

I don't think that anyone is arguing that the RS drivers are good, but the Scans are better. I believe they measure flatter and with less distortion. Better drivers, better sound. Less expensive drivers can overcome distortion by using multiple to keep them in a more linear area and avoid distortion, but think what multiple expensive Scans could sound like. It's hard to describe, but easier to hear. Someday....

[Hdale85]

I've heard from several people that the Scanspeaks are the best mids they had ever heard. I think going big bucks on something like mids is not a horrible idea and then going with something cheaper for the woofers where distortion isn't as BIG of an issue although generally still important but something like the RS180 is quite low distortion so should work nicely. My thoughts anyways

[Curt C]

How to describe the difference? Idunno… I’ll try: Clearer, more precise. Definitely more airiness. No veil covering things up. Relatively speaking, the Dayton MT sounds muddier. You know, the typical audiophile babble. But it seems like a significant difference to me. Ask Ryan. He’s less biased about it than I am. I have too much wrapped up in the design of that speaker to be objective, although I do try.

When I replaced the RS180/RS28 in my Exclamations! with the C92/OWIII, I found the most obvious improvement was in the midrange frequencies, with much better resolution of low level detail. Perhaps you will be willing to comment on them when you hear them at Iowa DIY next weekend.

C

[JonW]

I've heard from several people that the Scanspeaks are the best mids they had ever heard. I think going big bucks on something like mids is not a horrible idea and then going with something cheaper for the woofers where distortion isn't as BIG of an issue although generally still important but something like the RS180 is quite low distortion so should work nicely. My thoughts anyways

Yeah, I was also guessing that if you want to cheap out on drivers somewhere, the woofers of a 3-way might be the best place for that. I’m not really sure, though. Haven’t tried that out.

I can see how the mids are important. I don’t have too much experience yet, but I’m thinking a really good tweeter is also important to have. It probably is helping the sound of my MT’s.

When I replaced the RS180/RS28 in my Exclamations! with the C92/OWIII, I found the most obvious improvement was in the midrange frequencies, with much better resolution of low level detail. Perhaps you will be willing to comment on them when you hear them at Iowa DIY next weekend.

C

Sounds excellent. Looking forward to hearing them. :T

Word on the street is that you can make 2 cans and a string sound better than most commercial speakers. So they must sound superb. In my case, I had to hide behind expensive (Scanspeak) drivers to make my first speaker design come out OK.

Lately people seem to be asking about the potential benefits of higher quality drivers. It could be educational to do a side-by-side comparison of 2 speakers of similar design but one using more popular drivers (e.g., Dayton RS) and the other using fancier ones (e.g., Acuton, Scanspeak, etc.). If both speakers are designed by the same person and relatively simple, it could be interesting to see what a bunch of people think. Perchance, are you bringing both the RS180/28 and the C92/OWIII speakers to Iowa?

[servicetech]

If your front mains are 3-way make your center a 3-way also. Otherwise you will run into phase problems around the crossover frequency between the mid/woofer. If the crossover frequency on your mains is 800HZ the woofer and mid phase response will be different than the single driver in the center covering the 800hz range. I've has this issue with my own center begin a 2-way and 3 way mains. I'll have to do 2 way mains or a 3 way center so they will all match. Not to mention a mid producing a 1500hz signal sounds quite different than a 6.5" woofer producing the same signal.

[chasw98]

Perhaps you will be willing to comment on them when you hear them at Iowa DIY next weekend.

C

Actually it would be great if YOU took the time to talk to a pair of speaker building wannabe's like Jon and myself! We might learn something! Looking forward to seeing Jim Holtz, Ryan, Dennis Murphy, and you Curt!

Chuck

[kgveteran]

If your front mains are 3-way make your center a 3-way also. Otherwise you will run into phase problems around the crossover frequency between the mid/woofer. If the crossover frequency on your mains is 800HZ the woofer and mid phase response will be different than the single driver in the center covering the 800hz range. I've has this issue with my own center begin a 2-way and 3 way mains. I'll have to do 2 way mains or a 3 way center so they will all match. Not to mention a mid producing a 1500hz signal sounds quite different than a 6.5" woofer producing the same signal.

No doubt the rule of thumb is identical mains.

[DS-21]

I use three centers WTMW.They rolloff around 50hz.I cross them over at 100hz with my receiver.

Why don't you just run them full-range? You won't lose much headroom or risk damage because of the sealed cabs' natural rolloff, and you may find the upper bass region improved. (Are your 4 Tumults still right under the screen, or have you moved them around the room?)

In my system, I've found a notable improvement in overall room response from 40-200Hz running the mains full-range with the subs at a 120Hz crossover. (LFE+Main mode in Denon-speak; subs are distributed around the room.)

Your mains have better midbass potential than mine (more Vd, more motors to spread out the heat), so you might find even better results. Especially since you're not running especially low inductance subs. (If there is an issue with the upper bass at all in your setup, it is with the upper bass performance of the Tumults.)

As for some of the other arguments, I don't think anyone here would run a different right speaker and left speaker, or put them on different types of stands at different heghts. So why a different center? It just does not make sense. I think it would be better to skip the center entirely than to deal with any deviation from identical. At least for multichannel music. There's no real concept of "high-fidelity" for movies, so I suppose that could be a different case.

[kgveteran]

Why don't you just run them full-range? You won't lose much headroom or risk damage because of the sealed cabs' natural rolloff, and you may find the upper bass region improved. (Are your 4 Tumults still right under the screen, or have you moved them around the room?)

I tryed a lower XO point and wasn't happy with taxing the dual 225's. I was watching Irom Man last night with the family and I really mis-spoke about my midbass. I'm not sure where i was going , but it's there, with loads of headroom.

I usually listen at 0dbMV. Audyssey calibrates at 75dbMV. I'm thinking that my system as a whole is running at about 50% while watching movies at 0dbMV.


After Audyssey calibrated my system I ran TrueRta. I was shoked at how it calibrated every channel the same. All the sweeps were exactly the same for all 7 channels. Leaves me wanting very little more. Audyssey did set my system to 40hz. I ran that for a WOTW demo and shut down my Outlaw M-200 mono amp which was my cente channel. I went back to 100hz and all seems fine.

Kg