eD a7s-650 room response

[Tungsten06GT]

Hey guys,

Check out my room response for the a7s-650 (at the listening position). The attached chart was actually measurements that I took with an spl meter and sinusoidal frequencies from 10 hz to 100 hz. There's about 40 different values in between, and the far left axis represents 10 hz and the far right is 100 hz. Also, ignore the scale on the y-axis for "actual" values, it's just showing the range of dB's across the frequency range.

So, I've tried about 5 or 6 different positions in my room for the sub, and no matter what, there's that huge peak from ~40 to 60 hz. Which definitely attributes to it sounding "boomy." Anyhow, my receiver will only allow you to adjust standing waves down to 63 hz, so there goes that option.

Someone else mentioned trying the Behreinger feedback destroyer. Any thoughts there? Also, anything else I could try? I've got an isolation platform on the way, so maybe that will help too?

Thanks in advance!

 

[Below10hz]

I am also interested in the A7-650's. I am thinking about getting 2 of them to handle my bass obsession.

I would be curious about the graph you posted. I do not see a scale on the bottom that would allow us to see the frequency response. Did it get cut off? Can you repost?

Thanks

 

[Tungsten06GT]

I am also interested in the A7-650's. I am thinking about getting 2 of them to handle my bass obsession.

I would be curious about the graph you posted. I do not see a scale on the bottom that would allow us to see the frequency response. Did it get cut off? Can you repost?

Thanks

Those are actually terrible measurements; correction factors weren't accounted for with my radio shack meter. See this post here, it's true to the actual response. The graph goes from 10 to 100 Hz (stepping up 10 Hz for each axis).

http://forums.audioholics.com/forums/showthread.php?t=68920

Since going with the feedback destroyer, I've been able to get a pretty flat output down to 12 Hz using minimal equalization to correct for the room response. I definitely recommend the a7s-650

 

[GranteedEV]

can you post an unsmoothed 1/10th octave graph?

 

[Tungsten06GT]

can you post an unsmoothed 1/10th octave graph?

Well, I took manual measurements at the frequencies specified by the spreadsheet located here:
http://www.pvconsultants.com/audio/eq/peq.htm

It automatically smooths the response, and while I suppose I could take the numbers and put it into a basic spreadsheet that wouldn't smooth it, I'm feeling a bit lazy Anything in particular you're looking for?

 

[Below10hz]

Just purchased three of these beasts. I am sure they'll rock the whole neighborhood when I crank them up.

 

[Tungsten06GT]

Just purchased three of these beasts. I am sure they'll rock the whole neighborhood when I crank them up.

Wow 3?? Any reason why the odd number?

 

[GranteedEV]

Well, I took manual measurements at the frequencies specified by the spreadsheet located here:
http://www.pvconsultants.com/audio/eq/peq.htm

It automatically smooths the response, and while I suppose I could take the numbers and put it into a basic spreadsheet that wouldn't smooth it, I'm feeling a bit lazy Anything in particular you're looking for?

well yeah i thought it was pretty amazing that you had no bass nulls.

 

[Tungsten06GT]

well yeah i thought it was pretty amazing that you had no bass nulls.

Are nulls pretty common and could it be that I have some but just not at the specific frequencies I tested? Would a frequency sweep be the better way to go, sampling a ton in between?

 

[GranteedEV]

Are nulls pretty common and could it be that I have some but just not at the specific frequencies I tested? Would a frequency sweep be the better way to go, sampling a ton in between?

I think so. DO you have REW?

 

[Tungsten06GT]

I think so. DO you have REW?

I don't... I never really thought about how to set that up, I just figured a handheld spl meter would get me close enough.

Despite my measurements, here is the response after using the BFD for equalization.. It sounds good to me

 

[Below10hz]

Wow 3?? Any reason why the odd number?

Easy explanation: I could only afford three

Another reason - might not be technically justified - my Velvodine SMS - 1 has only 3 outputs. It would actually be a bit of a tight fit for 4 but I can do 3 and just have enough room.

 

[GranteedEV]

I don't... I never really thought about how to set that up, I just figured a handheld spl meter would get me close enough.

aw come on... REW is free. IMO it's worth it to tweak it... for such an expensive sub, why not?

 

[Tungsten06GT]

aw come on... REW is free. IMO it's worth it to tweak it... for such an expensive sub, why not?

Haha Even though I'm going to get blasted for this, I have it in the spot where I want it and figured I would equalize with the least amount of filters possible (all nulls aside). Seeing a more detailed plot won't make me sleep any better at night. Plus, it wasn't as expensive as it could have been (I went the DiY route -- muuuch cheaper).

 

[Rob Babcock]

That's a lot of sub! And the Feedback Destroyer is a very powerful unit when used as a parametric EQ. I used one for years to good effect.

 

[Tungsten06GT]

Thanks! Here's a couple pics of how I finished it. It was a diy gloss black, done purely with spray paint. I never would have believed I could have gotten a finish like this with spray paint, but I'm very satisfied