Do you have anything beyond it just being described as a Yamaha Subwoofer?  A model number would be a good starting point.

My problem, is this: I have 2 subs and they seem to bottom out every time a big explosion happens. I have my Sony receiver set to 0 on the level for the subwoofer but sometimes even ther it bottoms out. What cut off frequency do other folks set on the subs? Also what volume do they set their subs to? Thanks for any help

Have you properly calibrated your audio system?

Yeah, I know. Obvious. That's where he should start before anything else.

As for cutoff frequency, that's the crossover frequency which rolls off the top end to blend better with your other speakers. If you have a crossover already set in your receiver, you don't need to set it on the sub.

Quoting davidperez:

Quote:
Nolesrule, I have not had it porperly calibrated, that is kind of were I am right now. This is what I have right now:

The 2 subs are across from each other at oposite ends of the room. The second button it set to Movie, the cut off is set to 60hz and the volume is set to 5. This is all on the subwoofer. 

On the receiver, the following related to the sub is as follows. The front speakers are set to small, I was told once to do this so that the recevier knows to send the low frequencies to the subs. The equalizer is on and the bass is set to 0. The D. Comp is set to Standard and the subwoofer level is set to -2.5. Setting to anything more that 0 will create some really bad distortion. When I switch to music with alot of bass, I have to set the level down to -5 so that the subs dont distort. Thanks for every ones help. David

Two subs oposite to each other? - Are they facing each other? - If this ist true, the setup can't work (except with a studio equalizer in front of them), since the bass waves of the two will interfere...

Anyway, did you try to use only one of them?

Concerning the Large/Small issue: if all speakers are in one line (else same problem as above) it is of no matter to the sub if the front speakers are set to large or small. It is a question of speaker capabilities and your personal preference which setting is better. I for myself prefer the large front speaker setting since the bass has more room with more speakers to deliver it...

Regards, AA

Stop using the cutoff on the sub, and use the crossover in your receiver, so you aren't missing any higher bass frequencies in your setup.

Secondly, calibrate with Video Essentials. Pick up an SPL meter at radio shack, and a copy of the VE DVD. Then calibrate so all your speakers are at 75 dB from the primary seating area, and your sub reads 83-85 dB at the primary seating area ( the SPL meter is less accurate at lower frequencies of the sub).

Another issue will be placement of the subs and phase. It's possible you may be overdriving them because they are cancelling each other out in their current positions. You could play with the phases on them to see if it makes a difference, or you could try locating them in the same corner (corners usually work best, but not always).

One trick some people use for finding ideal subwoofer placement is to put the subwoofer in the listening position, and then go around the room till you find the spot where the sound coming from it is loudest. That spot would be the ideal placement for the sub.

Stacking subs or placing them next to each other are easier to set up than subs placed across the room from each other.

Quoting davidperez:

Quote:
i dont understand how having two subs or even the placement of the subs will make them bottom out. My subs are across the room from each other. About 10 feet away from each other. How does that make them both bottom out? When I say that they are bottoming out, I mean that they sound liek they are getting tooooo much bass coming to the. Is my EQ setting ok? nolesrule said to stop using cut off on the sub, how do I do that?

This has something to do with physics, amplitudes and waves. You have two soundsources emitting exactly the same waves and now depending on the frequency, the roomsize and the distance, you have two possibilities when these waves hit, either they flatten out each other (means this part of the frequency spectrum is not to be heard) or they level up (means this part of the frequency spectrum is overproportional loud) for a subwoofer this ends with too much bass.
You can easily check this effect in your bath tub (the principle is the same, is sound)

Re-read what nolesrules said above, he had several good sugestions.