Originally Posted by Chirosamsung
Hey Jerry, when I did my dual subs I “think” I did what you recommend in the first part of this response (not sure).
What I did was 1st physically measure both subs to MLP to set the distance/delay and input that into the MiniDSP (was only 0.67 as they are almost same distance away from me). Then, I used REW to generate automatic EQ for the subs at that distance and then I exported that to the MiniDSP. Then I did my DIRAC room correction after that. That’s all I did and though that was all I was supposed to do.
I didn’t do your second part which is to match or align the dual subs with the mains. A couple questions:
1) at what point am I supposed to do that part in my sequence; after the MiniDSP gets the exported auto eq curves and worth the room eq still off or do that after I have done Dirac?
2) is this part very important? Am I missing something by just eqing subs and then running Dirac?
3) by mains and matching mains, do you mean just the front left and right towers or the towers and the Center channel or all my 5.1.4 speakers?
4) is there a page number in the REW quite that this instructions are? I have been going back and forth over the last month and trying to slowly learn and digest parts of REW but have to admit that at times it is daunting and takes some rereading to wrap my head around concepts
You were correct when you measured the physical distance of each sub to the MLP and set the delay in the 2x4. However, this must be verified using REW, because physical measurements are not as accurate as acoustic measurements. Refer to the section in the 2x4 Setup Guide linked in my sig, page 21, "Checking Sub Alignment using REW Impulse Response Measurement". This procedure will verify the subs are aligned with each other.
Next step is to measure the combined
sub response using REW, and using the combined response as input to REW's EQ tool. Apply the resulting PEW filters to the combined
sub signal. Do NOT measure subs individually and apply different PEQ to each sub. Summing equalized individual subs does not necessarily produce an optimized combined sub signal. Besides, we listen to the combined signal, not the individual sub signals.
Next step is to run the Dirac Live calibration.
Final step is to measure subs+mains (I typically use subs+center). Observe the flatness of the response in the crossover region. If not as flat as you would like, use the "Sub distance tweak" procedure to improve the response, as described on p. 14 of the 88A-BM Setup Guide linked in my sig.
I have never found it necessary to time-align the mains--Dirac has always done an excellent job of time alignment.