Subwoofer set up for two-channel

**ebenai** · **03-01-09, 03:31 PM**

Hi guys: Need some help. I have a rel strata subwoofer connected directly to the main speaker binding post (high level connectionr recommended by REL). I'm trying to measure the subwoofer response with REW and this is what I have gotten so far. Measurement was done with the sub tuned as per REL manual. The room is 14x10x9. The crossover is at about 25 and the gain about a quarter of the total. I'm a I doing something wrong o this is just poor room acoustics? I appreciate any guidance

**Wayne A. Pflughaupt** · **03-01-09, 03:39 PM**

Let's start with the basics. What seems wrong to me is that a subwoofer low passed at 25 Hz looks like it runs as high as one crossed over at 100 Hz...

Regards,
Wayne

**ebenai** · **03-01-09, 04:41 PM**

OK. Not surprised. I think the sound card was calibrated correctly. Levels were checked using the subwoofer (mains disconnected) and the SPL (digital RS) was calibrated as per the instructions. I will remeasure let's see how it goes.

**ebenai** · **03-01-09, 04:46 PM**

This is the sound card.

**ebenai** · **03-01-09, 05:46 PM**

Hy guys. I really appreciate you input. The following are measurements of the sub at 4 different rolloff frequencies: 95, 64, 43, 30. Can this subwoofer be simply to big for the available space.

**Wayne A. Pflughaupt** · **03-01-09, 06:21 PM**

Okay, it looks like your crossover is working. To answer your original question...

Quote:

I'm a I doing something wrong o this is just poor room acoustics?

...you might want to experiment with some different locations, if that's possible. This one isn't good.

P.S. make sure any graphs you post use a 45-105 dB vertical axis.

Regards,
Wayne

**Kal Rubinson** · **03-01-09, 06:22 PM**

Quote:

ebenai wrote:

Hy guys. I really appreciate you input. The following are measurements of the sub at 4 different rolloff frequencies: 95, 64, 43, 30. Can this subwoofer be simply to big for the available space.

Or the other way? Looks like the upper one has the lowest crossover.

**ebenai** · **03-01-09, 06:29 PM**

That's right. The last one has the highest crossover. Now, I experimented with some different locations, mostly along the side wall and 1-1.5 feet from the corner equidistant from both walls and the changes were minimal. I also tried to puts some home made fiberglass panels about 2 inches thicks in corners, etc but no luck.

**Wayne A. Pflughaupt** · **03-01-09, 08:14 PM**

I'd try a corner that with the longest uninterrupted wall length in both directions.

Regards,
Wayne

**ebenai** · **03-02-09, 08:09 AM**

Thanks Wayne:

I think I found a better location but it isn't the corner. I will post some measurements tonight. I'm working on the mains. Will post some graphs as well. This forum is terrific. Great place. Appreciate all your help.

**ebenai** · **03-04-09, 07:14 PM**

Hi: I took my a little way but this is the latest curve for the sub now sitting on one of the lateral walls about 3 feet in from of one of the monitors. Rollofff set at 43 htz. Then I also attached a graph of the main without the sub and main plus the subwoofer with rollof at 30 hz.. I would appreciate any input. I tried placing the monitors in vairous locations in this is one of the flatest (no too falt though!)

**ebenai** · **03-04-09, 07:21 PM**

Sorry: The attachements weren't in the appropiate format

**Wayne A. Pflughaupt** · **03-04-09, 08:26 PM**

Thanks for the graphs. To answer your original question...

Quote:

I'm a I doing something wrong o this is just poor room acoustics?

...Not sure if by "doing something wrong" you're referring to your REW graphing, or the response you're seeing. So I'll answer for both: The graph looks fine, the response is indeed the result of room acoustics.

Also, it looks like your mains are running full range. That usually isn't good.

Still think you should try a corner for the sub...

Regards,
Wayne

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