NHT SW2P not enough?

Having a problem with my NHT sub . . . . for soundtracks and music, it sounds fine -- tight, solid, plenty of oomph. But when it comes to HT transients, like explosions, the impact just isn't there. I've played around some with positioning, but not a lot. I do have a pretty large room, and the SW2P is only a 10" driver with an 80 watt amp.

Do I need a) a sub with more power, b) a sub with better extension, or c) a lesson in subwoofer placement?

Any help appreciated!
Consider adding another SW2P if room permits.
What main speakers are you using the SW2P with? How big is your room? How loud are you listening in home theater? I have an SW2P also with the MA1 amp (80 wpc). I recently thought of upgrading to another NHT amp such as the MA3 with 250 wpc, but NHT said the SW2P wouldn't take that much power, but I could add a second woofer, however their current models would not match the driver in the SW2P. I also don't have the room for a second sub.I bought a used REL from a friend instead. I received an article explaining why 2 subs are better than one. Do you have the room to use 2 subs? If you do, that would be an option to explore. I may put up my SW2P for sale on Audiogon if I don't use it in my kids playroom soundsystem.
Howard (docradman@aol.com)
Or sell your current one and buy a bigger, badder one altogether. However, subs are the perfect first time diy endeavor if that's an option and/or of any interest. (A driver + an amp + a box). But if you want "impact" for "HT transients" from the aftermarket crowd something like the Sunfire might be more up your alley (if your bank account will permit).

2 subs will give you the luxury of stereo bass (whether or not is audible depends on the room somewhat) and it will help smooth out frequency response--both good things. But you seem to be more interested in the output/spl department. In an article in Audio years ago there was an experiment with the use of two subs and what best way to position them within a variety of rooms in relation to stereo bass audibility and spl levels attained. The author's findings, and its been along time since I've read it and I don't know where the article is so I may be a little wrong, was that 1) within there tests with pure test tones down in the deep bass territory, no one could reliably localize the sounds origin (now if your room is 70feet wide its different story) 2) they got the greatest output in most of their rooms placing both subs in one (the same) corner. Someone else may know of something new, more academic, or definitive on the stereo bass issue. But if you mains can go pretty low, one better sub might give you everything 1)low end ooomph 2)the stereo thing won't be an issue. (I can't recall the article addressing room nodes and multiple subs.)

I used to own the SW2P, it wasn't much--the amp was pretty cheap having inspected it, but the cabinets were pretty dense. Obviously if you buy another sub for stereo it'll be and SW2P, I couldn't see running two different models of subs in one room.
Here are my specs:

Room size is about 12' x 25', give or take, but it's also open on one side (to the kitchen and hallway). Ceilings are 9 1/2 feet.

I've got lots of space in the room for a second sub, but not much up with the other gear -- my 51" TV, dual centers, L/R mains, and rack have taken up most of that 12' in width.

My main L/R speakers are NHT 2.3As, centers are a pair of 1.3As wired in parallel. They've been being driven by an older Denon receiver, but as of the end of this week they will be feeding off of a Rotel 985 MKII.

I don't listen at earthshattering levels, but when something explodes you should feel it . . . .

I originally had the sub located in the front right corner of the room, but I got horrible resonances from the walls of the room -- just that kind of humming that you feel going right through your sinuses ;-0). So I moved it out from both walls, and it now sounds much cleaner and tighter, just not enough slam for HT stuff.

I've heard lots of different things about two subs -- it's good, it's bad . . . . I'd certainly appreciate any opinions on that, too -- SW2Ps are certainly cheap enough used.

Thanks for all the opinions so far!!
"I've heard lots of different things about two subs -- it's good, it's bad . ."

Its never bad, you won't create problems. Lots of professionals have setups with stereo subwoofers. Question is just "what's best for your setup and wanting more output?"

I won't recommend alot, but maybe look around this site some www.adireaudio.com

and this specific model seemed designed for what you want.


If you could get an audition with a return policy ir would be a sure-fire way to know if its your thing. The prices are very reasonable and maybe within your budget (1/2 the price of sunfire). Alot of DIY'er love'm and you could email for there experiences/opinions.
Actually, as it turns out, the problem has taken care of itself. I hooked up the Rotel 985 to my 2.3A front speakers today, and miraculously an extra 40-50Hz of bass appeared! (Guess I should have expected that.) With the front speakers now putting out a healthy amount of low frequency energy, I have plenty of bass with just the one sub.

Thanks for all the suggestions, though!