Why do subs sound bloated or slow?

Mine are the REL B 2 (pairs) and are far to be bloated and slow ..........

Thanks for the responses so far. In the OP, I wasn't trying to suggest that all subs sound bloated or slow. I was trying to identify some reasons, WHEN subs do sound bloated or slow, WHY that is the case.

Undoubtably, some of those reasons involve the design of the subwoofer itself, as Shadorne indicated. But I have noticed that, even with a well designed sub, seamless integration into a 2 channel system is very challenging. In the OP, I was proposing a theory that explains why sub integration into 2 channel systems so often fails, namely that it tends to result in one of the following scenarios:

1. Good transient response but poor frequency response. Hence "bloated."
2. Good frequency response but poor transient response. Hence "slow."

The reason why the above scenarios are so common, I believe, is because the measures taken to optimize frequency response are often bad for transient response, while the measures taken to optimize transient response are often bad for frequency response.

Has anyone else had this experience during sub setup?

Bryon

If you have good speakers in a 2 channel system a sub is not necessary. Use it for tv.

I have $15,000 speakers in a 2 channel system and the subs make them sound much better. My RELs are in the corners, where REL recomends that they be.

I agree with Plato. I also run two channel fronts and I have a Paradigm Signature Servo subwoofer. This Paradigm sub has its own Class D amp to power the woofer and three controls knobs to control phase, cut-off and loudness.

Because I only have one sub, I also bought a Paradigm X-30 crossover unit. The X-30 has the same controls and also allows me to combine left and right channels without shorting my pre-amp Mains. I feed my main fronts off the preamp's Main 1 output to the power amp. I run my fronts straight out. I feed the X-30 off of the pre amp's Main 2. output As stated, I use the X-30 to combine the two channels into one channel for the subwoofer.

My front speakers are Paradigm Signature 8 v2. The fronts roll off at roughy 35-40HZ. Of course room placement also affects base contour. However, as a general matter, I cross the sub over at 40-50HZ. Based on my ear, that sounds about right. Too high a cross-over and the bass sounds boomy. Too low, and bass is thin.

I also adjust phase by ear. I listen for the best sounding bass response. Loudness often varies by source material, but as I got used to working with the sub controls, I don't move the adjustment controls around too much.

I understand that Paradigm's current subwoofer line-up offers a bass adjustment kit which uses a small mike to sample bass contour, phase and loudness information directly into the woofer's self contained power amp. The sub's amp does all the work and makes the necessary adjsutments. That's about as good as it gets.

Anyway, I hope this helps. For those of you whose subwoofer doesn't allow cross over, phase and loudness adjustments, I suggest buying a cross over control box like the Paradigm X-30. It really works. BIF