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Subwoofer integration into home theater set up

Jerry Sobel

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I am trying to integrate my 2 subwoofers into my home theater set up. I recently purchased a MiniDSP 8 channel set up and I have it all connected by XLR. I have 2 mains, a center, surround R/L and two subs. The dsp runs Dirac Live and I also have the bass management plug-in. I read a few different methods of getting the subs integrated and settled on the Multi Sub Optimizer program (MSO) which is a tedious process but hoping it would be worth it. I got my two subs well aligned by the program in each of three listening positions and then ran the Dirac Live set up. I went to listen to a movie last night and the bass was way way too much. I had to dial down my subs from 0 dB to -15 db and it was still not quite right. I have a Marantz 8801 AVR and everything on that has been turned off. I am not sure what I am not doing correctly but it is something. On my subs (SVS PB16 Ultras) if I want I can set multiple parameters but I would prefer that the dsp do that.

I was thinking about either running both subs from one output using a y connector or going onto REW and balancing the 2 subs to a few listening positions and taking those numbers and putting them into the bass management plug in. That is what the MSO is supposed to do but somehow something got messed up.

Any suggestions?
 

RayDunzl

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Hmm...

In my case, a pair of 15" subs flanking the mains on each side, and not separated by frequency (mains run all the way down, subs duplicate 23-100Hz or so)...

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With no correction, measure the mains on one side.

Add one sub, adjust volume on the sub and remeasure for +6dB in the bass range.

Add a second sub, adjust volume on the sub and remeasure for +9dB in the bass range.

Repeat for the other side. (Now the subs and mains are pooting forth with equal - but too much - bass)

Run the 2-channel room correction, for which I choose "flat" in the bass, which rebalances the overall bass signal levels, and reduces the output of all the bass drivers equally.

And I'm good enough. My cheezy 150W subs and the mains run at reduced power (-9dB?) and distortion, no boom, nice definition to differing bass instruments.

If it's a little ragged around the room, well, As it was in the beginning, and now, and ever shall be, cancellations without end. Amen.

At least it's not bugging me.

Even a movie rarely goes over-the-top-on-the-bottom.

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This doesn't help you, but may give you an idea or two for balance before, and to maybe help, autocorrection.

---

@dallasjustice seems to have the resident multi-driver split-dsp bass setup expertise
 
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DonH56

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Andy (MSO author) is a member of ASR though much more active on AVS where there is a thread on MSO. MSO didn't used to work well with only two subs but I think he has been working on that (not sure but he's a nice -- and very smart -- guy, ask him).

You can "Y" to the subs if they are are identical with respect to the listening position, meaning same distance and same environment around them. Other wise you'll need to adjust the phase (delay) on them to get them aligned.

I do not have a miniDSP so could offer only hand waving and there are a lot of variables. I suggest PM'ing Andy (@andyc56 ) here and asking him to check this thread since you are already on the MSO path.
 
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astr0b0y

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Are you creating an internal y-cable by sending the sub channel out to both outputs simultaneously? Even though you can select multiple channels in Dirac as tick them as subwoofers, this is not the correct way to do things. Doing it this way had unexpectedly poor results for me.
 
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Jerry Sobel

Jerry Sobel

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Are you creating an internal y-cable by sending the sub channel out to both outputs simultaneously? Even though you can select multiple channels in Dirac as tick them as subwoofers, this is not the correct way to do things. Doing it this way had unexpectedly poor results for me.
I have an external y cable but have not used it. I used MSO and then did the BM plug in set up per Austin Jerry on AVS and that means both subs out one Dirac channel so that it only sees the one sub
 

stunta

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I recently purchased a MiniDSP 8 channel set up and I have it all connected by XLR

Can you please link to the specific MiniDSP unit? I cannot find any that has 8 XLR I/O plugs. Thanks
 

stunta

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Can you please link to the specific MiniDSP unit? I cannot find any that has 8 XLR I/O plugs. Thanks
Nevermind. They have Phoenix connectors and sell adapters. I have never seen such a thing before.

XLR%20to%20male.jpg
 

bigx5murf

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IME, AVR sub output usually has a very gently sloping crossover, so even if you've set the crossover to say 80Hz. Your mains are probably still getting signal down to 60-70Hz. That might be the cause of your issue with excessive bass..
 
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Jerry Sobel

Jerry Sobel

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Can you please link to the specific MiniDSP unit? I cannot find any that has 8 XLR I/O plugs. Thanks
It is the DDRC-88A. The Phoenix plugs I had never used before either. They work great. I had one faulty one and mimiDSP sent me an entire new unit.
 

stunta

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@Jerry Sobel Did you solve the problem? I had a similar issue and realized my bass management filter settings were incorrect. There is also a section on "Gain structure" and "LFE gain alignment" in the manual that are worth reading in case you haven't already.
 
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Jerry Sobel

Jerry Sobel

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Hi, yes I did figure it all out. Thanks for asking.
 
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Jerry Sobel

Jerry Sobel

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It was a long time ago and I cannot completely remember. I think I just went ith the bass management and minidsp and did not use the separate subwoofer program.
 

stunta

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It was a long time ago and I cannot completely remember. I think I just went ith the bass management and minidsp and did not use the separate subwoofer program.

Uh, I must be losing my mind. I didn't realize this thread is almost a year old! Thanks.
 
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