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Integration of Two Subs with miniDSP Flex

Hi All,

I have a pair of bookshelf speakers (Fritz LS7 Illuminators) and recently purchased two SVS SB 1000 Pro subs. All of these are in my dedicated audio room.

The second sub is a recent purchase.  I integrated the first sub with the mains using REW measurements and manually tweaking the phase, level, and 3 available PEQs on the SVS.

The results weren’t bad, but I had to run the sub up to 80Hz to address a null and my mains are spec’d down to 38Hz, so quite a bit of overlap.  I thought I’d get another sub as I’ve head that having two with adjustable phase and PEQs can really help smooth out the bass region.

Not having faith I could manually configure the two subs or that their included limited DSP levers could give me the best overall response for my room, I just purchased a miniDSP Flex to help integrate the subs as well as give me options to EQ for my specific room. I haven’t purchased the Dirac Live option and would like to see what I can achieve with the standard Flex features before spending more $.  I will use the Flex as my preamp as it has enough inputs for me.

I’ve read through the Flex manual once and have used the measurement options of REW already, but the recommended or best-practice process for sub integration and EQ is completely new to me.

I understand that REW has an AutoEQ option that can generate a PEQ file that can be uploaded to the Flex.

My initial questions are:
1) Do I generate an AutoEQ file for each bookshelf speaker separately? So I do a separate sweep and AutoEQ for L and R speakers individually?

2) Similar to above, do I sweep each subwoofer individually and generate an individual AutoEQ for each?

3) Even if I have experimented previously and have found an optimized phase setting for each SVS, do I sweep each sub with phase set to 0 degrees and somehow REW will compensate. . .or do I run the initial sweep with phase already set to what I believe is the best value?

4) Once I set generate AutoEQ files for all 4 speakers (L/R/Sub1/Sub2), how do I know where to set the LPF for the subs and HPF for the mains?

5) Once I load all the AutoEQ files to the Flex and set LPF and HPF, then I run a REW sweep with all 4 speakers simultaneously driving and the resulting sweep should get me close to the target curve?

6) If the resulting sweep curve above has issues, what iterative process do I go through to refine things? Or is it just manual tweaking at that point?

6) Should I not worry about FIR filters and Compression at this point?

I know Dirac Live is supposed to automate a lot of the room correction stuff, but looking at the Dirac website, it says that the Flex supports the base Room Correction module, but not the Bass Control module.  So if my initial focus is two sub integration with my mains, I’m not sure how much buying the Dirac license does for me without the use of the Bass Control module.

 

Thanks all.

captouch

Showing 2 responses by erik_squires

erik_squires
16,805 posts
 

One of the things I really like about the LS7’s that use the Illuminator mid/woofer is how fast and detailed instruments like acoustic bass get rendered.

It's true and in the right rooms you almost don't need a sub at all, but if you are going to go that route... you may be surprised just how much better your mids and even imaging will be with proper integration with the subs.

Another good source of information is the AM Acoustics room mode simulator which will help you find ideal spots for your subs, main and listening location. 

erik_squires
16,805 posts
 

You should take your REW questions to that forum, but generally speaking, sub integration is not that complicated.  miniDSP has a really good document on how to do so here.

Fritz is an excellent choice of main speaker.  Before integration though I’d suggest you consider your room acoustics.  Fritz travels with 4-6 panels in hotel rooms for a reason.  A  highly reflective room will make those speakers sound unbalanced and lack bass.  I’d strongly suggest you deal with that before making further adjustments.  

A couple of other tips is to go as high as you can with your subs. 80 Hz is great.  Measure with the speaker ports sealed.  I use 100% virgin alpaca wool from a hidden tribe in the Andes who only come out to trade with others once very 50 years.... OK, sorry, that’s a joke.  Just clean socks in the ports.  This is a tip for almost any ported speakers when you have enough subs.  It makes integration a little easier and reduces distortion a little.  Of course, it’s reversible so if you hate it you can pull the socks out. 

Unfortunately many audiophiles fall into the trap of "I bought main speakers that go down to 25 Hz so I only need a sub for 5 Hz more!"  

Seriously, eff that, especially with high pass filters via miniDSP.  Plug your mains, set the high pass filters at 80 Hz and try to do 4th order.  That will make crossing to a sub with 4th order low pass super simple. 

Good luck! 

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