freq. response charts

[samandnoah]

I have one, alot of rooms I have set subs up in have that dip. Don't know why, they just do.

SheepStar

I'm late in reading this thread, but I'll venture a guess as to why so many rooms have a dip ~ 60Hz: ROOM DIMENSIONS!

The wavelength of 60 Hz is approx 18'10" (using speed of sound of about 1,130 ft/sec, you divide it by the frequency to get the wavelength). If you have two wavelengths of the same frequency, but out of phase (i.e. 1/2 wavelength apart) you get cancellation.

So, if you have a dip around 60Hz, you're looking for 1/2 wavelength dimension, which in this case would be around 9' 5". You also have the potential of getting this kind of cancellation if the center of the woofer driver is ~ 1/4 of wavelength (or 1/8, etc.) from room surfaces, especially if two or more. So if the sub is in a corner, but out a couple of feet you can get this as well.

I learned this lesson the hard way with some speakers (not sub) that I mounted.

Good luck.

Oh, MikeC -- nice looking room. And nice bass traps, but I thought those were *ss traps?!

Rich

 

[cyberbri]

Here's the frequency response I got when I measured at my LP with 1/3 octave tones through my HTPC, bass coming through both Ascend 340SE mains and HSU VTF-3 Mk2 sub.

(here's the gallery with a bunch of pics of my new Ascend/HSU toys)

I plan on getting some room treatments to hopefully smooth that out and tighten up the bass (although the Ascends and HSU are already incredibly tight and musical) - GIK bass traps or 244s at the least for the front corners. There's probably not much I can do about first reflection points, as I have a chair and window/blinds along the right wall, and fireplace on the left wall.

Thanks Buckeye_Nut for recommending them. I have seen their website before, along with a few other companies. But GIK seems to have good stuff for reasonable prices (and custom colors).

 

[mike c]

I took to heart the comments that my room is bright as hell ... area rug to follow ...

 

[Mark Seaton]

Hi Mike,

Indeed, couches, and especially a row of them, can have a significant impact on the low frequency response. I once had to go back out to a friend's house to re-adjust the subwoofer when he added a large couch to the back row. He was surprised that the sound had changed a good bit when he changed the seats and the measurements clearly explained why.