Advice welcome ;-)

[Steviewunda]

Hi - I'm a new user of REW with 5.2 speakered Denon receiver, MiniDSP 2x4 HD, 2 x different but similar 12" sealed subs. I would really appreciate anyone checking out my attached .mdat file and advising me how to improve on the result I currently have. The subs have been gain-matched, time-aligned and eq'd in REW then sent to the MiniDSP, and I'm hoping someone more experienced can suggest a way to boost the 20 - 100hz region, and to smooth the curve more. And i'd be grateful if someone could explain how to do a full range measurement using ASIO drivers instead of Java - the Asio drivers are easier to use for sub measurements (I dont have to raise crossovers, etc on the receiver), but I can't see how to do a full-range measurement using ASIO drivers. (You'll see that I changed to Java for the last 2 full-range measurements). All suggestions gratefully received
Cheers
Steve

 

[jtalden]

The EQ'ed response of measurement 5 in the mdat looks very good. It is not likely that that there is much improvement to be made. What is the concern?

I do see that the 2 SW are current setup with opposite polarity. If you are starting over with a new setup then I suggest you reverse one of them. The max SPL output will be higher and the smoother initial SPL will require less EQ in order to smooth the response, i.e., more headroom. The chart below shows the smoother SPL of the combined SWs when one has its polarity reversed prior to EQ. Measurement 3 (purple) is the current setup prior to EQ and Measurement 8 (green) is with the polarity reversal of one of them.

 

[Steviewunda]

Thank you very much for your reply! I don't have any particular concerns, just being new to REW and MiniDSP I was after reassurance that I was using it correctly. I'm surprised about the polarity thing - I thought I had made sure they had the same polarity. How can you tell they don't?

 

[jtalden]

The overlay step response chart can be used. The initial rise of the step response is in different directions with the current polarities.

Current polarities:

Reversed polarity on f SW (blue):

The overlay phase chart is the better indicator, but takes a little more experience to understand it well. Basically close phase tracking throughout most of the bandpass range indicates the most favorable polarity relationship between the 2 SWs.

Current Polarities are tracking 180° apart through the 25-120 Hz range:

Reversed polarity on f SW (blue) now tracking closely throughout the 25-120 Hz range: