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Integrating 4 sealed subs in 1 room

466 Views 15 Replies 11 Participants Last post by derrickdj1, Mar 15, 2015

LowellG

Discussion Starter · Mar 13, 2015

I currently have 2 PSA XS30s. I have owned them for a little over a year now and have never been able to get a good curve with REW. Please don't ask for my graphs. I have tried at least 50 different positions, tried the Audessey sub distance tweak, etc. The best I have been able to do is get a +/- graph with about 7db drops in multiple places, it all depends on where the subs are placed with where the dips are at. However with the highs and lows it can go about 14 db between some ranges. I.E. It may start at 90 DB at 15Hz, but go up to 97db at 40Hz and down to 83db at 50hz. Then it will stay up between 60 -80 and drop at 90 again. And I see a similar curve no matter where I place the subs, all that changes in the frequency range.

So, my latest config has one XS30 behind left and front right. However, I have found I really like the bass in back supporting the surrounds, it brings a whole new sound and feel, but it's still not perfect. The XS30 is a little tight in my back area too, so I thought about moving it back in front and adding 2 SVS SB2000s in back. I figure the front subs would run off of sub 1 out with a Y-splitter and the rear subs would run off sub 2 with a Y-splitter. Currently a Denon X4000.

Too see my room specifics, just click on my link.

Will I have integration problems? Any advice would be greatly appreciated.

Thanks,

1 - 16 of 16 Posts

Alan P

· #2 · Mar 13, 2015

Not quite sure what you're complaining about Lowell.

Or, has your graph changed since you posted this in your HT thread?

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LowellG

Discussion Starter · #3 · Mar 13, 2015

Alan P said:
Not quite sure what you're complaining about Lowell.

Or, has your graph changed since you posted this in your HT thread?

It's changed. I haven't been able to repeat that.

Kini62

· #4 · Mar 14, 2015

LowellG said:
It's changed. I haven't been able to repeat that.

Can't you put the subs back to where they were when you ran this graph?

Maybe there is something wrong with your mic.

As for a pair of SB2000s, if you try it and don't like it, it costs you nothing.

I run two very different subs, with the lesser sub sort of nearfield in the back left corner and my good sub in the front right. Adding the SC8000 in the back did wonders to fill out the sound field.

I don't want to measure anything, it sounds great to me and I prefer to be oblivious to any nulls and peaks.

Sometimes not knowing is better than knowing and obsessing over it.

Reactions: 2

Hopinater

· #5 · Mar 14, 2015

Kini62 said:
Can't you put the subs back to where they were when you ran this graph?

Maybe there is something wrong with your mic.

As for a pair of SB2000s, if you try it and don't like it, it costs you nothing.

I run two very different subs, with the lesser sub sort of nearfield in the back left corner and my good sub in the front right. Adding the SC8000 in the back did wonders to fill out the sound field.

I don't want to measure anything, it sounds great to me and I prefer to be oblivious to any nulls and peaks.

Sometimes not knowing is better than knowing and obsessing over it.

This is very wise advice. The key is if you are happy with it than that's all that matters.

Having said that I wasn't happy so I ran REW and when I saw my graphs I realized why I wasn't happy so I moved things around (a lot, over and over) and finally got some decent graphs and things sound better.

Lowell have you ever considered getting a minidsp and lower the peaks a bit? The $100 or so on a minidsp is a lot less than the cost of two SB2000s. Just a thought. Oops, never mind. Just saw your post below mine and you already ordered the new subs.

LowellG

Discussion Starter · #6 · Mar 14, 2015

Kini62 said:
Can't you put the subs back to where they were when you ran this graph?

Maybe there is something wrong with your mic.

As for a pair of SB2000s, if you try it and don't like it, it costs you nothing.

I run two very different subs, with the lesser sub sort of nearfield in the back left corner and my good sub in the front right. Adding the SC8000 in the back did wonders to fill out the sound field.

I don't want to measure anything, it sounds great to me and I prefer to be oblivious to any nulls and peaks.

Sometimes not knowing is better than knowing and obsessing over it.

I just ordered them.

I am taking your approach on nothing to lose, plus I I got the dual discount plus a 5% military discount on top of it. I really want the deep base of both XS30s in the front corners and now I like the base with the rears. It just changes the overall sound.

tvuong

· #7 · Mar 14, 2015

^^ why not trying with a pair of XS15's?

BassThatHz

· #8 · Mar 14, 2015 (Edited)

I think you are running into the limits of your bass management.

You have to add delay to the closest subs. So if the furthest sub is at 20ft, and the next closest is at 8ft, then you need to add 12ft of delay to the sub that is at 8ft. etc etc
If you have 4 different distances then you will need a DSP that can handle 4-independent subs, such as a: miniDSP or DCX.

Generally you want to find the 4 best spots (or if they are all clustered together, a single-best spot), you then have 4 independent EQ channels.
Then you can check the total sum of them in pairs or as a whole, and adjust the same EQ settings for all 4 channels.
At least, in-theory.

Usually the loudest spot for a sub is directly behind your head (

Reactions: 1

Teremei

· #9 · Mar 14, 2015

LowellG said:
I just ordered them. I am taking your approach on nothing to lose, plus I I got the dual discount plus a 5% military discount on top of it. I really want the deep base of both XS30s in the front corners and now I like the base with the rears. It just changes the overall sound.

Sounds pretty good. I didn't check your size room but I pretty much just have 4 placement options. 4 corners. I finally settled on the 2 larger deeper subs up front and my midbass sub at back. My sound is really full, and clean enough. Point being, need to clean up your sound? Just run a sub in each corner! If you don't mind spending the money that is.

Gorilla Killa

· #10 · Mar 14, 2015

+1 on getting a miniDSP.

LowellG

Discussion Starter · #11 · Mar 14, 2015

tvuong said:
^^ why not trying with a pair of XS15's?

I did, but there just a little to physically large.

LowellG

Discussion Starter · #12 · Mar 14, 2015

BassThatHz said:
I think you are running into the limits of your bass management.

You have to add delay to the closest subs. So if the furthest sub is at 20ft, and the next closest is at 8ft, then you need to add 12ft of delay to the sub that is at 8ft. etc etc
If you have 4 different distances then you will need a DSP that can handle 4-independent subs, such as a: miniDSP or DCX.

Generally you want to find the 4 best spots (or if they are all clustered together, a single-best spot), you then have 4 independent EQ channels.
Then you can check the total sum of them in pairs or as a whole, and adjust the same EQ settings for all 4 channels.
At least, in-theory.

Usually the loudest spot for a sub is directly behind your head (

doublewing11

· #13 · Mar 14, 2015

As fore-mentioned above............1/4 space front and back gives smoothest FR. Across seven seats, I'm only 2 db's difference from 10 Hz to 80 Hz. Granted, it's only a 48 ft square box.........but it is doable. I'm using Minidsp Open Drc so a pair of subs to each channel.................

derrickdj1

· #14 · Mar 14, 2015

The ideal of adjust the EQ in pairs is what I use with my four sub. The front two as a single unit and the rear subs as a second unit. I Also use a 4 subs asymmetrically located partly due to the room but, also for the purpose of not exciting the same mode. Some of this is just experimenting with the sub/room.

craig john

· #15 · Mar 14, 2015

derrickdj1 said:
The ideal of adjust the EQ in pairs is what I use with my four sub. The front two as a single unit and the rear subs as a second unit.

Do you, as a final step, EQ all 4 subs together? After all, when you listen to the subs, you are hearing all 4 subs together. IME, EQ'ing 2 subs as a unit, and 2 other subs as a another unit can result in flat response for each unit, but when combined, the "final" response is no longer flat.

derrickdj1 said:
I Also use a 4 subs asymmetrically located partly due to the room but, also for the purpose of not exciting the same mode. Some of this is just experimenting with the sub/room.

I run 3 subs asymmetrically placed, but I EQ all 3 subs as one unit. 2 subs are equidistant to the PLP, so they get one distance setting. The 3rd sub is closer, so it gets it's own distance setting. Then all 3 are combined and one EQ filter set is applied to all the subs.

Craig

derrickdj1

· #16 · Mar 15, 2015

craig john said:
Do you, as a final step, EQ all 4 subs together? After all, when you listen to the subs, you are hearing all 4 subs together. IME, EQ'ing 2 subs as a unit, and 2 other subs as a another unit can result in flat response for each unit, but when combined, the "final" response is no longer flat.

I run 3 subs asymmetrically placed, but I EQ all 3 subs as one unit. 2 subs are equidistant to the PLP, so they get one distance setting. The 3rd sub is closer, so it gets it's own distance setting. Then all 3 are combined and one EQ filter set is applied to all the subs.

Craig

In the end all four are EQ togethered. There are only minor differences in the PEQ between the pairs since two are vented and two are sealed. They play nice together and the FR graph looks pretty darn good.

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