My first REW try.

**mjb1023** · **08-04-09, 11:09 AM**

Here is a look at the REW sweep of my Martin Logan Descent I sub using a Behringer UCA202 as my sound card and a new Radio Shaft analog SPL meter.
Since I am a Noob at this, I would appreciate any input or advice.
Name: day one, no eq.jpg
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Size: 51.3 KB

Name: day one, no eq.jpg
Views: 168
Size: 51.3 KB

**brucek** · **08-04-09, 12:19 PM**

Quote:

I would appreciate any input or advice.

Very nice response. It certainly goes low. If you're not using any external EQ, then you're quite lucky - you don't need any....

Use the standard vertical axis of 45dB-105dB using the Graph Limits button in the top right corner of REW.. You're being kind to yourself with that wide axis you're using.

brucek

**mjb1023** · **08-04-09, 06:38 PM**

Thanks brucek for the suggestion about the graph. I still might buy a BFD to smooth out the spikes at 41 and 65 hz. Here is the adjusted graph...a little more ragged looking now that it is "zoomed in".
Name: day 1, 45-105 db graph adjust.jpg
Views: 154
Size: 54.9 KB

Name: day 1, 45-105 db graph adjust.jpg
Views: 154
Size: 54.9 KB

**brucek** · **08-04-09, 07:32 PM**

Still a fairly good response though. have you tried moving the sub around at all to better the peak at 40Hz? Sometimes a small change will affect a peak.

Did you also try moving the listening position mic around a few feet at least from the sweet spot to observe changes.

brucek

**Wayne A. Pflughaupt** · **08-04-09, 07:57 PM**

Quote:

Here is a look at the REW sweep of my Martin Logan Descent I sub...

Very impressive! I wasn't aware that any major manufacturer made an off-the-shelf sub that would get below 10 Hz!

Regards,
Wayne

**mjb1023** · **08-04-09, 09:33 PM**

Yeah, I'm kind of surprised myself because Martin Logan only rates the Descent I to 18hz. The only thing I can figure is that I have adjusted the Descent's 20hz eq knob to +4db and the 50hz knob to -3db when I first set up the sub. Maybe that boost at 20hz is working some magic in the infrabase as well
I will play with REW a little more tomorrow.

**weverb** · **08-06-09, 07:53 AM**

Quote:

mjb1023 wrote:

Yeah, I'm kind of surprised myself because Martin Logan only rates the Descent I to 18hz. The only thing I can figure is that I have adjusted the Descent's 20hz eq knob to +4db and the 50hz knob to -3db when I first set up the sub. Maybe that boost at 20hz is working some magic in the infrabase as well
I will play with REW a little more tomorrow.

Is it placed in a corner? That will also help boost the low end. Other than that, I would think we should see the response naturally start to roll off and it is not.

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