# Weird bass effect, odd room.



## romnation (Mar 20, 2010)

First off, I want to state that I am actually using a Velodyne SMS-1 to do my subwoofer equalization, not REW. I figured this would probably be a good place to find good information on my issue. The SMS-1 uses a Behringer ECM8000 measurement mic and allows for equalization of a sub via the tv screen. The sweep it generates for its graph is 1/3 octave.

I have a 2 dedicated 2 channel music room. (running b&w 805s and rythmik audio 12" sub. I use an NHT-X2 external cross over, which is a 12db/octave locked crossover. i don't use any of the crossover functions on the SMS-1 ) I have my high pass filter set to 80hz, as well as my low pass. Is this how I am supposed to set it, or is there a better way to do if for better integration?

Here are some pictures of my odd room, it is not perfectly rectangular, and has a section of the wall that sticks out farther than the rest. ignore the fact that it is a mess right now:
http://i43.tinypic.com/291c1u1.jpg
http://i39.tinypic.com/140xkle.jpg

I used to have my sub placed in the "corner" behind my amps (a bit to the left of my turntable) When it was placed there I used my SMS-1 to EQ for a flat response. I had to use a very significant amount of EQ for this placement. The end result sounded pretty good but was maybe a tad "bloated"

I decided to experiment with some more placement options. I measued the response at the left corner of my room (where the sub is now) and noticed there was less peaks and dips in that spot, and it would be much easier to EQ. I flattened out the response with the SMS-1 again and threw on some cds. They sounded very good, and the bass sounded very accurate. However, on cds with heavy bass I get an odd effect in my left ear when certain bass is playing. (This is only noticable when listening to music, not in test tones) It seems as if something is vibration left eardrum, and it just feels odd, and unaturla and bothers me when listening. IT almost seems as if something is too loud and is bothering my ear. It takes away from the music. I did not have this weird effect where my sub used to be. Is this due to the fact that I'm only using one sub and I'm hearing the directionality of the subwoofer? Or maybe it's reflection off of walls? Or is it something else? Maybe the SMS-1 is missing a peak or two since it's only 1/3 octave? If it's a directionality issue, I would assume the best idea would be to add another sub. If I do that, where should I place it?

Edit: Here are all of the dimensions in my room:
http://i42.tinypic.com/mj4v94.jpg


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## arande2 (Dec 25, 2009)

I have the same problem. I couldn't tell you why, though - letting you know you're not alone. Personally, I would expect a second sub on the opposite side of the room to solve it.

Maybe others will chime in, as I would like to know, too.


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## Wayne A. Pflughaupt (Apr 13, 2006)

Moving the thread to the BFD /Equalizers Forum, since it has nothing to do with REW.

I’ve had the same problem. I’d attribute it to air pressure, but then I was sitting much closer to the speakers than it appears that you are – only 9-10 ft away. Left and right subs did the trick, kind of. I had the vibration thing in both ears, but at least things were balanced and it didn’t sound like all the bass was coming from one side of the room.

By the way, I hope you have some kind of delay on your speakers, to time-align them with the sub?

Regards,
Wayne


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## romnation (Mar 20, 2010)

Wayne A. Pflughaupt said:


> Moving the thread to the BFD /Equalizers Forum, since it has nothing to do with REW.
> 
> I’ve had the same problem. I’d attribute it to air pressure, but then I was sitting much closer to the speakers than it appears that you are – only 9-10 ft away. Left and right subs did the trick, kind of. I had the vibration thing in both ears, but at least things were balanced and it didn’t sound like all the bass was coming from one side of the room.
> 
> ...


I don't have a delay, although if I get an additional sub and place each sub next to a speaker will I even need one? I don't know how I could add a delay to my system without adding an additional component, thus harming the sound. Also I am about 6 1/2 feet from my speakers.


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## glaufman (Nov 25, 2007)

Don't want to scare you, but I would get evaluated by a Doc.


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## romnation (Mar 20, 2010)

Also I do not notice any audible delay. Is there any good way to test?


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## Wayne A. Pflughaupt (Apr 13, 2006)

romnation said:


> I don't have a delay, although if I get an additional sub and place each sub next to a speaker will I even need one?


If the subs - or even just the one - were next to the speakers, no delay would be needed.




> I don't know how I could add a delay to my system without adding an additional component, thus harming the sound.


Worse than what the delay is probably causing?




romnation said:


> Also I do not notice any audible delay. Is there any good way to test?


 Typically you'll see anomolies in response through the crossover region. Measurements with REW would verify this.

Regards,
Wayne


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