One sub or two?

Two subs are better. No question about it. I've tried it both ways.

Just bought 2 M&K 150 watt 8'' subs. 2 will spread throught the room better. And, at 190.00 each, the deal was good. Sometimes I use just 1 for AB comparison, but I'm glad I got 2 small subs instead of 1 big sub, at lease for 2 channel.

If you cross over to the subs very high (>100hz to 150hz), there are 3 very clear POTENTIAL benefits to a pair of subs vs. a single sub. However, the key word is "potential" and the ability to realize that potential will depend upon - among a few other things - what device you use to effect the crossover.

1) At a sufficiently high x-over points (per above) you can maintain stereo integrity.

However...

At some point - people seem to debate exactly what point - the crossover frequency is low enough that bass becomes monophonic and this benefit does not persist, per Phasecorrect.

2) Careful placement of a pair of subs will provide MUCH!!!! smoother FR in most rooms. Not even close. This is IMHO the biggest benefit of a pair of subs BY FAR. IME, a subwoofer almost always interacts with the room to create peaks and dips that will exceed +/- 10db at the listening position. A pair of carefully placed subs can reduce that to +/- 3 or 4 db. This is an immediately audible difference.

However....

If your x-over is effected with a PrePro that has Audyssey, ARC or similar digital room correction ("DRC"), or stand-alone correction/x-over like the Velodyne SMS-1, you can get to the same place by EQing a single sub.

3) You will always get more clean output potential from a pair of subs than from a single sub (assuming that the subs in question are the same model).

However...

A single high output sub may cost less than a pair of lower output subs.

Bottom line:

#2 is the key. If you are using DRC, a second subwoofer is a nice luxury. If you are not, a second subwoofer will almost always provide VASTLY smoother bass response.

All IME. However, ME is now up to 5 years of continuously tweaking subs in my system, so I feel pretty good about this advice. I really doubt that YMMV.

Marty

I went from dual NHT subs with an NHT X2 sub crossover to a single REL Storm III using speaker level connections. In my room, the Storm III was a nice improvement. But it must be said that I am lucky enough to not have any nasty room modes and I am crossing over quite low at 40Hz. And damn do the REL subs integrate well with speakers.

I just added one sub to my analog system. I can't locate it or specifically hear it. However, if I turn it off, I notice it and the missing LF. I have a fair sized room 17d x 35w w/14ftcathedral ceilings, a 8ft wall behind and another 17 x 35 kitchen/dining room on the other side. The sub is set about half way. It's a NSM 15EXP with a10in driver. Plenty of bass for me. Mated with C & C Abby's.