Calling those with multiple subwoofers - Page 2 - AVS Forum
View Poll Results: Why did you incorporate multiple subwoofers in your home theater?
To even-out the bass response in the room 26 33.33%
To increase overall SPL 2 2.56%
To even-out bass response and increase overall SPL 50 64.10%
Voters: 78. You may not vote on this poll

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post #31 of 77 Old 05-16-2014, 06:21 AM
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Okay so if you listening area is close to the TV & speakers then it doesn't matter if your room is small or large, that's good to know.

How are people using 4 subwoofers, aren't most receivers only .2?
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post #32 of 77 Old 05-16-2014, 06:34 AM
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Quote:
Originally Posted by whatupdet View Post

Okay so if you listening area is close to the TV & speakers then it doesn't matter if your room is small or large, that's good to know.

How are people using 4 subwoofers, aren't most receivers only .2?

http://www.minidsp.com/products/minidsp-in-a-box/minidsp-2x4
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post #33 of 77 Old 05-16-2014, 06:38 AM
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^^ that or Y cable splitters.
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post #34 of 77 Old 05-16-2014, 07:03 AM
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I use 4 subs...2 in front and 2 in back, with y-splitters. I use the pre-amp to time-align the front pair vs the back pair, since they are different distances.

In a closed rectangular room, a sub in each corner plus room EQ is a great way to go, IMO. Optimal combination of room gain, pretty flat and consistent frequency response, and lack of nulls.
(Your mileage may very. Every room is different.)
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post #35 of 77 Old 05-16-2014, 07:17 AM
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Quote:
Originally Posted by Kain View Post

Some questions...

Does having more subwoofers produce bass that sounds "larger" or "bigger"? Just like how bigger speakers, generally, produce a larger sound, does having more subwoofers produce bass that sounds more "expansive"?

If I have 4 subwoofers placed in the 4 corners of the room (well not exactly the corners, more like 4/5th of the wall's length towards the corners), and calibrate each subwoofer individually to 75 dB and then run all 4 together, how hot would my bass end up being? Is this what most do or do they calibrate to 75 dB with all subwoofers operating together resulting in greater headroom as each subwoofer will be working less?
I actually consider an expansive sound from subs to be undesirable. Ideally, it should sound like the subs don't exist, and that great bass is coming from your speakers. For the lowest frequencies, it should feel like you are really there. If it sounds like the upper bass is coming from everywhere, it may mean that the crossover frequency is too high or that the subs have high distortion.

If your main speakers are small and need a higher crossover point, that can be the best compromise, all things considered. On the other hand, a crossover point that's too low means you miss out on the ability to use sub placement to cancel out room modes. For me, 80hz was the optimal compromise.
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post #36 of 77 Old 05-16-2014, 10:07 AM
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The room has the same number of modes. The bass mode are spaced out more the lower the frequency.

Klipsch RF 7 based HT 7.4, Pioneer SC 35, Acurus Five 200 amp, Chase SS 18.2(2), VS 18.1(2), Samsung BDP F 7500, Asus/My Book Live HPC 4 TB

Yaquin VK 2100 amp, McIntosh XR 5 speakers, Samsung BDP F 7500
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post #37 of 77 Old 05-16-2014, 10:17 AM
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After reading the Harman White Papers, that's what convinced me to go with multiple subs. http://www.harman.com/en-us/ourcompany/innovation/pages/whitepapers.aspx

I quickly went from 2 to 4 subs, and recently renovated my room so I can utilize the 4 subs at each wall midpoint, which is suppose to be an ideal setup.

I have a couple pieces of furniture to get rid of before I can place the 4th sub at the back midwall, but even with a sub at 3 midwalls the results are impressive, and without correction or eq at this point.

 
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post #38 of 77 Old 05-16-2014, 01:34 PM - Thread Starter
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According to the Harman White Papers, they say that 4 subwoofers at the midpoints of the walls leads to the smoothest "natural" response but "hurts" low frequency response. 4 subwoofers in each of the corners leads to the best low frequency response but does not offer the smoothest "natural" response. Does this mean if you want the best low frequency response, you should place the 4 subwoofers in the corners and let the pre/pro smooth out the response?
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post #39 of 77 Old 05-16-2014, 02:31 PM
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Quote:
Originally Posted by Kain View Post

According to the Harman White Papers, they say that 4 subwoofers at the midpoints of the walls leads to the smoothest "natural" response but "hurts" low frequency response. 4 subwoofers in each of the corners leads to the best low frequency response but does not offer the smoothest "natural" response. Does this mean if you want the best low frequency response, you should place the 4 subwoofers in the corners and let the pre/pro smooth out the response?

It doesn't sound like you could go wrong with any of the recommended placements.

"One subwoofer at each wall midpoint is the best in terms of
Std, Max-ave and Max-min but does not support low
frequencies particularly well. Two subwoofers, at opposing
wall midpoints, performs very nearly as well as four at the
midpoints and gives a much better LF factor. One
subwoofer in each corner also has good low frequency
support, but does not perform quite as well as one
subwoofer at each wall midpoint, in terms of Std, Max-ave
and Max-min."


In my case I have more sub than my room can handle and I value smooth response over max spl, so that's why I chose wall midpoint locations for my subs.

If I were running 4 smaller subs with less output than perhaps corner placement would be the right move.

 
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post #40 of 77 Old 05-16-2014, 03:57 PM
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Quote:
Originally Posted by Kain View Post

Here is a quick diagram of my room:

ZtIfU4c.jpg

Basically, I have 4 subwoofers in each corner of the home theater with the left/right front speakers and the left/right surround speakers placed on top of the subwoofers. The surround speakers will be angled towards the seating position. Even though I have not illustrated it, the front left/right speakers will also be slightly toed-in.

The subwoofers will be the SubMersive HPi+ (all with amplifiers and none as slaves so that I can EQ each one separately).
Pre/pro could be the Datasat RS20i.
I don't have any experience measuring rooms so if I do it this time, it will be my first time.
Four Submersives in a room slightly larger than 1,00 cubic feet... will be the dictionary definition of overkill. Not that there's anything wrong with that. smile.gif Whether you place them in the corners or the midwalls, you'll have so much headroom that output won't be an issue. With a DataSat RS20i to set delays and EQ, you'll be able to correct for any possible FR or time domain issues.

Having said that, if you plan to do the installation and integration yourself, you'll definitely want to learn how to use measurement gear. Spending that kind of money on equipment absolutely deserves proper setup. Either hire someone to do it for you, or learn how to do it properly yourself.

One comment about your diagram...

In a 5.1 system, the "surrounds" should be at 90 to 110 degrees. Where your surrounds are placed in your diagram is where the rear surrounds would be placed in a 7.1 system:






Here is THX's recommendation:





If you can, try to move the surrounds to the more appropriate locations. You can leave the subs in the corners and just move the speakers. They should be slightly above ear level.

What speakers do you plan to pair with the SubM's and the DataSat? Do you have any plans for acoustic treatments?

Craig

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post #41 of 77 Old 05-16-2014, 04:11 PM - Thread Starter
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Quote:
Originally Posted by craig john View Post

Four Submersives in a room slightly larger than 1,00 cubic feet... will be the dictionary definition of overkill. Not that there's anything wrong with that. smile.gif Whether you place them in the corners or the midwalls, you'll have so much headroom that output won't be an issue. With a DataSat RS20i to set delays and EQ, you'll be able to correct for any possible FR or time domain issues.

Having said that, if you plan to do the installation and integration yourself, you'll definitely want to learn how to use measurement gear. Spending that kind of money on equipment absolutely deserves proper setup. Either hire someone to do it for you, or learn how to do it properly yourself.

One comment about your diagram...

In a 5.1 system, the "surrounds" should be at 90 to 110 degrees. Where your surrounds are placed in your diagram is where the rear surrounds would be placed in a 7.1 system:






Here is THX's recommendation:





If you can, try to move the surrounds to the more appropriate locations. You can leave the subs in the corners and just move the speakers. They should be slightly above ear level.

What speakers do you plan to pair with the SubM's and the DataSat? Do you have any plans for acoustic treatments?

Craig

Planning on this:

LCR: 3 x Seaton Sound Catalyst 12C
Surrounds: 2 x Seaton Sound Catalyst 8C
Subwoofers 4 x Seaton Sound SubMersive HPi+ (all with amplifiers and none as slaves)
Pre/pro: Datasat RS20i

I will be using acoustic treatments but haven't really planned anything out just yet.

Regarding the surround placement, I have another thread going on that: http://www.avsforum.com/t/1531321/surround-speakers-at-ear-level-acceptable

Basically, I cannot place the surround speakers at a 90 degree angle to the listening position because one side of the room has a large built-in closet and the other side has a door that leads to a terrace. That is why I have them positioned behind me.

Some questions regarding surround and speaker placement:

1. I will be placing the left/right front and surround speakers on a subwoofer (center will be on a stand). Will this be okay or would be better to use stands? I am asking because, in my small room, I won't have any other place to place the subwoofers if I use stands for all the speakers (unless I reduce the number of subwoofers).

2. If I end up placing the speakers on the subwoofers, will an ear-level height for the surrounds be acceptable? I've seen quite a few home theaters with ear-level surrounds but still want to make sure.

3. I think the angle for the surround speakers will be around 120-130 degrees. Is this too much?

4. I shouldn't force-in two more surrounds for 7.1, right?
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post #42 of 77 Old 05-16-2014, 04:48 PM
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Quote:
Originally Posted by Spanglo View Post

After reading the Harman White Papers, that's what convinced me to go with multiple subs. http://www.harman.com/en-us/ourcompany/innovation/pages/whitepapers.aspx

I quickly went from 2 to 4 subs, and recently renovated my room so I can utilize the 4 subs at each wall midpoint, which is suppose to be an ideal setup.

I have a couple pieces of furniture to get rid of before I can place the 4th sub at the back midwall, but even with a sub at 3 midwalls the results are impressive, and without correction or eq at this point.

I like your commitment to going multiples. It's what needs to be done to get perfect bass. I haven't done it but I seem to be slowly working my way there, I just went to two subs and find myself considering more. 

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post #43 of 77 Old 05-16-2014, 04:50 PM
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Quote:
Originally Posted by Kain View Post

Planning on this:

LCR: 3 x Seaton Sound Catalyst 12C
Surrounds: 2 x Seaton Sound Catalyst 8C
Subwoofers 4 x Seaton Sound SubMersive HPi+ (all with amplifiers and none as slaves)
Pre/pro: Datasat RS20i
That will be an incredible system. cool.gif
Quote:
Originally Posted by Kain View Post

I will be using acoustic treatments but haven't really planned anything out just yet.

I suggest GIK Acoustics. You can contact them via their webpage and they'll provide an acoustic treatment plan. Their products are great and work as advertised.
Quote:
Originally Posted by Kain View Post

Regarding the surround placement, I have another thread going on that: http://www.avsforum.com/t/1531321/surround-speakers-at-ear-level-acceptable

Basically, I cannot place the surround speakers at a 90 degree angle to the listening position because one side of the room has a large built-in closet and the other side has a door that leads to a terrace. That is why I have them positioned behind me.
I have a door where my right surround needed to go. Here's how I dealt with it:





The mount is a Pinpoint AM40 which can hold 50#. The Cat 8C's are 66# so you would need a different mount. OTOH, see my answer to Question2 below...
Quote:
Originally Posted by Kain View Post

Some questions regarding surround and speaker placement:

1. I will be placing the left/right front and surround speakers on a subwoofer (center will be on a stand). Will this be okay or would be better to use stands? I am asking because, in my small room, I won't have any other place to place the subwoofers if I use stands for all the speakers (unless I reduce the number of subwoofers).
With the complete lack of cabinet vibrations with the SubM's, placing a speaker on top of it is fine. Just put something in between to keep the cabinet finish from getting scratched.

Quote:
Originally Posted by Kain View Post

2. If I end up placing the speakers on the subwoofers, will an ear-level height for the surrounds be acceptable? I've seen quite a few home theaters with ear-level surrounds but still want to make sure.
My concern is that the surrounds will fire directly into the ears of the closest listener. That would be distracting. Raising them reduces that. If you can't do that, then the placements you have in your drawing would be a better compromise.
Quote:
Originally Posted by Kain View Post

3. I think the angle for the surround speakers will be around 120-130 degrees. Is this too much?
IMO, yes. But you may still be required to use those angles.
Quote:
Originally Posted by Kain View Post

4. I shouldn't force-in two more surrounds for 7.1, right?
IMO, no. But you could consider using Wides. If you must have the surrounds behind you, a set of Wides would fill in the "hole" between the Fronts and Surrounds. (oops, nevermind... the DataSat doesn't do Wides.)
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post #44 of 77 Old 05-16-2014, 07:10 PM
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Quote:
Originally Posted by Kain View Post

According to the Harman White Papers, they say that 4 subwoofers at the midpoints of the walls leads to the smoothest "natural" response but "hurts" low frequency response. 4 subwoofers in each of the corners leads to the best low frequency response but does not offer the smoothest "natural" response. Does this mean if you want the best low frequency response, you should place the 4 subwoofers in the corners and let the pre/pro smooth out the response?
In my rectangular room, 4 subs at 4 wall centers gave me poor response and poor power, contrary to that Harmon paper. Subs at the front and back center gave me the best response but poor power. Four corners gave me good response (no nulls) and good power. In that setup, the seat-to-seat consistency was also good, so it was easy to EQ for good response and good power. The power difference was so big that that 4 corner setup gave be much better overall sound.

(BTW, the 1/4 3/4 setup, similar to what you drew also gave good natural response for me, just not as much power as corner placement.)

Moral of the story, always good to measure.
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post #45 of 77 Old 05-16-2014, 07:17 PM
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With that calibre of equipment, you might consider a projector, rather than a TV!
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post #46 of 77 Old 05-17-2014, 01:17 AM - Thread Starter
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Thanks for the replies!

Some more questions...

1. What if I place the surrounds on stands and those stands on the subwoofers? This will allow me to have 4 subwoofers and also increase the height of the surrounds. The left/right front speakers will not on be stands but directly placed on the front subwoofers.

2. Would placing the speakers on the subwoofers (left/right fronts and surrounds) put too much physical pressure on the subwoofer cabinets? Do I need to worry about this?

3. My local IMAX theater has, I think, a 5.1 setup. There are only two surround speakers and both are located pretty much at the back wall while being slightly toed-in. Isn't this angle also far greater than the recommended 90-110 degrees?

4. I can only support a TV size of about 65" max. I don't think there is any reason to get a projector. Plus, I'll have to deal with fan noise and bulb replacements.

5. The problem with placing the surround on the door like you posted, the door is actually in the small path-way in my drawing. I would have to place the sofa/couch pretty much against the back wall for this to work. Secondly, the sliding door on the other side of the room is made of glass (I have not illustrated this door in the drawing but it is opposite to the long table-like thing in the drawing). Not going to work. The long table-like thing running in my drawing is the built-in closet. Cannot mount any speakers to it because I highly doubt it will support them.
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post #47 of 77 Old 05-17-2014, 06:50 AM
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Quote:
Originally Posted by Kain View Post

Why did you incorporate multiple subwoofers in your home theater?

Because my wife let me smile.gif
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post #48 of 77 Old 05-17-2014, 06:45 PM
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No problem placing speakers on subs.

Have you considered a false wall and an acoustically transparent screen? Whatever makes you happy, of course, but I would think that a 65" screen will seem tiny compared you the world-class audio experience you will have.
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post #49 of 77 Old 05-18-2014, 08:05 AM
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Quote:
Originally Posted by Kain View Post

Thanks for the replies!

Some more questions...

1. What if I place the surrounds on stands and those stands on the subwoofers? This will allow me to have 4 subwoofers and also increase the height of the surrounds. The left/right front speakers will not on be stands but directly placed on the front subwoofers.
I would be concerned about the stability of the speakers, especially if they are in a "traffic pattern." You don't show doors in your diagram, so I can't tell if the speakers would be in a traffic pattern or not, but if they are, I would be concerned about them getting bumped or moved or even falling off the subs. Otherwise, if that's not an issue, then you should be fine. As I said before, the SubM cabinets are completely inert, so vibrations are not an issue.

Quote:
Originally Posted by Kain View Post

2. Would placing the speakers on the subwoofers (left/right fronts and surrounds) put too much physical pressure on the subwoofer cabinets? Do I need to worry about this?
This is not an issue at all. The SubM cabinets are strong enough to hold the speakers, on stands or directly on top of the box. I initially placed my Atlantic Technology THX U2's on top of my SubM's. They didn't weigh quite as much as the Cat8's, (53# vs. 66#), but there was no problem at all. I've already sat on my SubM's during bass heavy content just to see if I could feel any vibration. I weigh 185# so 66# should be no problem.

Quote:
Originally Posted by Kain View Post

3. My local IMAX theater has, I think, a 5.1 setup. There are only two surround speakers and both are located pretty much at the back wall while being slightly toed-in. Isn't this angle also far greater than the recommended 90-110 degrees?
https://www.imax.com/about/experience/sound/


quote name="Kain" url="/t/1531465/calling-those-with-multiple-subwoofers/30#post_24728745"]4. I can only support a TV size of about 65" max. I don't think there is any reason to get a projector. Plus, I'll have to deal with fan noise and bulb replacements.[/quote]
Big sound benefits from a big image. I'm just sayin'...


quote name="Kain" url="/t/1531465/calling-those-with-multiple-subwoofers/30#post_24728745"]5. The problem with placing the surround on the door like you posted, the door is actually in the small path-way in my drawing. I would have to place the sofa/couch pretty much against the back wall for this to work. Secondly, the sliding door on the other side of the room is made of glass (I have not illustrated this door in the drawing but it is opposite to the long table-like thing in the drawing). Not going to work. The long table-like thing running in my drawing is the built-in closet. Cannot mount any speakers to it because I highly doubt it will support them.[/quote]
You gotta do what you gotta do. wink.gif


Unsolicited Editorial Comment, (and even though you didn't ask...):

I have to say that the system you're planning will be MASSIVELY overwhelming to your room. You'll be able to control it with the Master Volume Control, but you are seriously paying for performance you will NEVER use... in that room. Your current room is just slightly over 1,000 cubic feet and it looks like you will be sitting about 9' from your front speakers. You could easily use Cat8's in the front and get just as good performance... and save yourself some significant coin. The 8C's are spec'd to 65 Hz and they're sealed. You could easily use an 80 or 100 Hz crossover with them, so the extra extension of the 12C's won't be utilized anyway. And with 4 subs, localization of the subs will be a total non-issue. I can see no benefit to the 12C's in your room/system. Maybe Mark Seaton has some other thoughts, and I suggest you ask him.

In terms of the subs, you probably only "need" 2, but if you must have 4, then 2 Master/Slave units will work equally well in your room as 4 separate HPi's... and once again you could save some significant money. Your room is small enough, and you'll be sitting close enough to your subs that you'll NEVER use the slight extra amp power that the separate amps provide. And with the Master?Slave units, the Master and Slave are, by definition "gain-matched" so you would only need to concern yourself with gain-matching the 2 M/S units to each other. Again, Mark may have some other thoughts, and I suggest you ask him. He's a straight shooter and he won't try to "over-sell" you.

Then take the money you save and put it towards room treatments. I can't express how important this is to your ultimate enjoyment of your system. The GIK site I linked previously has some great info on the benefits of acoustic treatment, as does the RealTraps website. Both companies will do treatment plans, and both ship internationally. If you don't want to buy from them, there are plenty of sites on the web that can provide instructions for building your own. Whatever you decide, I strongly urge you to not skip this step. Spending tons of $$$ on speakers and electronics won't guarantee you a great sounding system. Your room will have a bigger impact on what you hear than any other component in your system. Don't ignore it.

End Unsolicited Editorial Comment...

Craig

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post #50 of 77 Old 05-19-2014, 01:46 AM - Thread Starter
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Quote:
Originally Posted by rcohen View Post

No problem placing speakers on subs.

Have you considered a false wall and an acoustically transparent screen? Whatever makes you happy, of course, but I would think that a 65" screen will seem tiny compared you the world-class audio experience you will have.

I agree, but I'm sitting about 7-8 feet from the screen so a 65" should be fine. I mean, right now, with my current home theater, I have a 42" screen and sit about 11-12 feet back. This will be a huge upgrade for me. tongue.gif

Quote:
Originally Posted by craig john View Post

I would be concerned about the stability of the speakers, especially if they are in a "traffic pattern." You don't show doors in your diagram, so I can't tell if the speakers would be in a traffic pattern or not, but if they are, I would be concerned about them getting bumped or moved or even falling off the subs. Otherwise, if that's not an issue, then you should be fine. As I said before, the SubM cabinets are completely inert, so vibrations are not an issue.

This is not an issue at all. The SubM cabinets are strong enough to hold the speakers, on stands or directly on top of the box. I initially placed my Atlantic Technology THX U2's on top of my SubM's. They didn't weigh quite as much as the Cat8's, (53# vs. 66#), but there was no problem at all. I've already sat on my SubM's during bass heavy content just to see if I could feel any vibration. I weigh 185# so 66# should be no problem.
https://www.imax.com/about/experience/sound/

Quote:
Originally Posted by Kain View Post

4. I can only support a TV size of about 65" max. I don't think there is any reason to get a projector. Plus, I'll have to deal with fan noise and bulb replacements.
Big sound benefits from a big image. I'm just sayin'...


quote name="Kain" url="/t/1531465/calling-those-with-multiple-subwoofers/30#post_24728745"]5. The problem with placing the surround on the door like you posted, the door is actually in the small path-way in my drawing. I would have to place the sofa/couch pretty much against the back wall for this to work. Secondly, the sliding door on the other side of the room is made of glass (I have not illustrated this door in the drawing but it is opposite to the long table-like thing in the drawing). Not going to work. The long table-like thing running in my drawing is the built-in closet. Cannot mount any speakers to it because I highly doubt it will support them.
You gotta do what you gotta do. wink.gif


Unsolicited Editorial Comment, (and even though you didn't ask...):

I have to say that the system you're planning will be MASSIVELY overwhelming to your room. You'll be able to control it with the Master Volume Control, but you are seriously paying for performance you will NEVER use... in that room. Your current room is just slightly over 1,000 cubic feet and it looks like you will be sitting about 9' from your front speakers. You could easily use Cat8's in the front and get just as good performance... and save yourself some significant coin. The 8C's are spec'd to 65 Hz and they're sealed. You could easily use an 80 or 100 Hz crossover with them, so the extra extension of the 12C's won't be utilized anyway. And with 4 subs, localization of the subs will be a total non-issue. I can see no benefit to the 12C's in your room/system. Maybe Mark Seaton has some other thoughts, and I suggest you ask him.

In terms of the subs, you probably only "need" 2, but if you must have 4, then 2 Master/Slave units will work equally well in your room as 4 separate HPi's... and once again you could save some significant money. Your room is small enough, and you'll be sitting close enough to your subs that you'll NEVER use the slight extra amp power that the separate amps provide. And with the Master?Slave units, the Master and Slave are, by definition "gain-matched" so you would only need to concern yourself with gain-matching the 2 M/S units to each other. Again, Mark may have some other thoughts, and I suggest you ask him. He's a straight shooter and he won't try to "over-sell" you.

Then take the money you save and put it towards room treatments. I can't express how important this is to your ultimate enjoyment of your system. The GIK site I linked previously has some great info on the benefits of acoustic treatment, as does the RealTraps website. Both companies will do treatment plans, and both ship internationally. If you don't want to buy from them, there are plenty of sites on the web that can provide instructions for building your own. Whatever you decide, I strongly urge you to not skip this step. Spending tons of $$$ on speakers and electronics won't guarantee you a great sounding system. Your room will have a bigger impact on what you hear than any other component in your system. Don't ignore it.

End Unsolicited Editorial Comment...

Craig[/quote]

Awesome, thanks! The issue with the slave subwoofers is that you cannot EQ them separately. You need to EQ the master and slave units as one. Will this be a problem? I was under the impression that the slave units were ideal for being stacked on top of the master unit (or placed very closely to the master unit).

Secondly, are the sound characteristics of the CAT-8C the same as the CAT-12C with the 12C being able to go a bit louder? Is this the only difference or does the 12C also have other improvements over the 8C?

Thirdly, do the CAT-8C and CAT-12C move around when the volume is very high? I know the SubMersive HPi+ will not but what about the 8C and 12C?

Fourthly, the reason why I am basically going for total overkill in this room is because I play it LOUD (provided the situation at the time is right). I need something that will keep up and have headroom to spare.

Lastly, how would the Klipsch RF-7 II compare to the CAT-8C (and maybe even the CAT-12C) when hooked-up to a high-powered separate amplifier?

P.S.: Don't worry, I will be incorporating acoustic treatments in this room. smile.gif
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post #51 of 77 Old 05-19-2014, 05:53 AM
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This may help with determining screen size and what is ideal. The common advice is to figure out what angle/ratio you prefer from a commercial theater. Whatever makes you happy, of course, but it's common for people to underestimate the benefits of a big screen and want more. That said, there is a point where it gets too big.

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post #52 of 77 Old 05-19-2014, 05:58 AM
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Quote:
Originally Posted by Kain View Post

Awesome, thanks! The issue with the slave subwoofers is that you cannot EQ them separately. You need to EQ the master and slave units as one. Will this be a problem? I was under the impression that the slave units were ideal for being stacked on top of the master unit (or placed very closely to the master unit).

Secondly, are the sound characteristics of the CAT-8C the same as the CAT-12C with the 12C being able to go a bit louder? Is this the only difference or does the 12C also have other improvements over the 8C?

Thirdly, do the CAT-8C and CAT-12C move around when the volume is very high? I know the SubMersive HPi+ will not but what about the 8C and 12C?
Generally, you want subwoofers to be EQ'ed as a group, not individually. You do want to be able to time-align subs separately when they are different distances from the listener. For example, I have 2 in front and 2 in back. I split the signal to the front pair and the back pair, but front vs. back have different delay.

My understanding with Cat 8 vs 12 is that output is the main difference. I can't imagine that they would move around.
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post #53 of 77 Old 05-19-2014, 06:11 AM - Thread Starter
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Quote:
Originally Posted by rcohen View Post

Generally, you want subwoofers to be EQ'ed as a group, not individually. You do want to be able to time-align subs separately when they are different distances from the listener. For example, I have 2 in front and 2 in back. I split the signal to the front pair and the back pair, but front vs. back have different delay.

My understanding with Cat 8 vs 12 is that output is the main difference. I can't imagine that they would move around.

I always thought that with multiple subwoofers, you EQ them individually first and then as a group. Is this wrong? Should I just EQ them as a group and forget EQing them individually first?
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I always thought that with multiple subwoofers, you EQ them individually first and then as a group. Is this wrong? Should I just EQ them as a group and forget EQing them individually first?
Skip EQing them individually. On an individual basis, all that matters is gain and delay. EQ them as a group.

With good placement, when they play as a group, the frequency response changes dramatically (hopefully) filling in the nulls.
Boosting the nulls individually before letting them sum together would hurt, not help.
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post #55 of 77 Old 05-19-2014, 06:21 AM
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Quote:
Originally Posted by Kain View Post

Awesome, thanks! The issue with the slave subwoofers is that you cannot EQ them separately. You need to EQ the master and slave units as one. Will this be a problem? I was under the impression that the slave units were ideal for being stacked on top of the master unit (or placed very closely to the master unit).

Secondly, are the sound characteristics of the CAT-8C the same as the CAT-12C with the 12C being able to go a bit louder? Is this the only difference or does the 12C also have other improvements over the 8C?

Thirdly, do the CAT-8C and CAT-12C move around when the volume is very high? I know the SubMersive HPi+ will not but what about the 8C and 12C?

Fourthly, the reason why I am basically going for total overkill in this room is because I play it LOUD (provided the situation at the time is right). I need something that will keep up and have headroom to spare.

Lastly, how would the Klipsch RF-7 II compare to the CAT-8C (and maybe even the CAT-12C) when hooked-up to a high-powered separate amplifier?

P.S.: Don't worry, I will be incorporating acoustic treatments in this room. smile.gif
First off, sorry I screwed up the quotes. redface.gif

As rcohen said, you don't want to EQ the subs separately. You *hear* the combined response. Therefore you want to EQ the combined response. If you place the front subs equidistant to the LP and the rear subs equidistant to the LP, (which they are in your drawing), you can place separate delays on them... and them EQ them all together. That is the optimal way to go.

In terms of the Cat12's vs. the Cat8's, there are 2 key differences: amp power and the 8" drivers vs. the 12" drivers. The Cat 12's have 1,000W-700W-300W vs. the Cat8's 500W-350W-150W. Note that the 12's have exactly double the amp power as the 8's. That equates to a 3 dB difference in max output. My point is that the 8's will have "more than enough output and the extra 3dB of the 12's won't ever be used in your room.
The other difference is the 12" drivers vs. the 8" divers. This equates a difference of an F3 of 50 vs. 65 hz. If you crossover at 80 - 100 Hz, this will make no difference.

I don't believe the Cat's will "move around" at high volumes, but someone who owns them would be better able to answer that question.

Klipsch RF-7 II vs. Cat8's? The Cat's will have more max output. The Rf-7's are "full range" speakers, so, if you cross them over to the SubM's at 80 Hz, (which you should), you'll be paying for a lot of LF extension that you won't be using.

Craig

Edit: You guys covered a lot of what I was saying.. while I was typing. smile.gif

Lombardi said it:
Perfection is not attainable, but if we chase perfection we can catch excellence."

My System

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Quote:
Originally Posted by Kain View Post

I always thought that with multiple subwoofers, you EQ them individually first and then as a group. Is this wrong?
Not wrong, just difficult. A computer algorithm could figure out the right combination of EQ for each subwoofer so that their combined output would sum to the desired result, but that would be out of the scope of us hobbyists. Instead, a better solution would be...
Quote:
Originally Posted by Kain View Post

Should I just EQ them as a group and forget EQing them individually first?
Yes. Your first form of "equalization" will be placement, which is helpful AND free (doesn't cost anything to move subs around). This then leaves less for electronic equalization to do, which basically needs to clean up what placement alone couldn't do. In both cases, placement and EQ, it is the interaction between your subwoofers that you'll be hearing, not the output of each individual sub. So it is the interaction between your subs that needs to be EQ'd, not the output of each individual sub.

Sanjay
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post #57 of 77 Old 05-19-2014, 01:11 PM
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Originally Posted by sdurani View Post

Not wrong, just difficult. A computer algorithm could figure out the right combination of EQ for each subwoofer so that their combined output would sum to the desired result, but that would be out of the scope of us hobbyists. Instead, a better solution would be...
Yes. Your first form of "equalization" will be placement, which is helpful AND free (doesn't cost anything to move subs around). This then leaves less for electronic equalization to do, which basically needs to clean up what placement alone couldn't do. In both cases, placement and EQ, it is the interaction between your subwoofers that you'll be hearing, not the output of each individual sub. So it is the interaction between your subs that needs to be EQ'd, not the output of each individual sub.

I learned that the hard way when I purchased a minidsp and took the time EQ each of my 4 subs individually, and when I saw the summed response I couldn't believe how bad it was. Being new to the game I figured the next logical step would be to EQ the subs in a pairs - which again failed to my surprise. But I didn't give up, and I applied the same EQ to all 4 subs and lo and behold I got a result worth talking about.
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post #58 of 77 Old 05-19-2014, 05:56 PM
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Also, check out the rectangular room simulator in REW for quickly experimenting with different sub layouts. I found it was surprisingly accurate in my room. YMMV.
http://www.hometheatershack.com/forums/downloads-area/47460-v5-01-beta-downloads-asio-support.html
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post #59 of 77 Old 05-20-2014, 03:53 AM
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Quote:
Originally Posted by Spanglo View Post

Quote:
Originally Posted by sdurani View Post

Not wrong, just difficult. A computer algorithm could figure out the right combination of EQ for each subwoofer so that their combined output would sum to the desired result, but that would be out of the scope of us hobbyists. Instead, a better solution would be...
Yes. Your first form of "equalization" will be placement, which is helpful AND free (doesn't cost anything to move subs around). This then leaves less for electronic equalization to do, which basically needs to clean up what placement alone couldn't do. In both cases, placement and EQ, it is the interaction between your subwoofers that you'll be hearing, not the output of each individual sub. So it is the interaction between your subs that needs to be EQ'd, not the output of each individual sub.

I learned that the hard way when I purchased a minidsp and took the time EQ each of my 4 subs individually, and when I saw the summed response I couldn't believe how bad it was. Being new to the game I figured the next logical step would be to EQ the subs in a pairs - which again failed to my surprise. But I didn't give up, and I applied the same EQ to all 4 subs and lo and behold I got a result worth talking about.

This, I was surprised too at how atrocious the combined response was when each sub was EQ d separately. Combined gave me the best overall response.
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post #60 of 77 Old 05-20-2014, 10:40 AM
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This, I was surprised too at how atrocious the combined response was when each sub was EQ d separately. Combined gave me the best overall response.

Truth be told I was able to get a good response by individual EQ, but it took forever and it was only good for one seat. I thought I had nailed it by getting a good response at the MLP, but when I tested other seats the response was again atrocious. So there went hours of testing different distances, levels, phase, and EQ.

Eventually I smartened up and averaged the response across multiple couches, then global EQ, and finally Audyessy. The response at the MLP wasn't as great as before, but it was consistently good on both couches so I considered that a win.

It was a good learning experience, because now I can do in mins what took me hours to do before.

 
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