HDTV Forum

Is one sub enough? I thought so, as my 15" Earthquake is quite the beast. But I recently had a second sub that I was selling for a friend and of course I hooked it right up on the other side of the room.

Now, they say the sound waves of a sub are so long that you can't really tell the direction they are coming from, but perceived or not, I thought it added balance to the room. I wish I had a third to see what that would sound like.

Cost is everything. If you do not have a budget then full range for all speakers is preferred but how many of us fit that scenario? As for not being able to tell direction with bass that is pure hogwash. As you have noted you can tell! I have always run stereo subs just for that reason. It is preferred your subs match each other just like your speakers. As for a third sub I would apply that to your center channel and possibly consider one more for the rear channels. Also, as you add these subs the amount of power and SPL required for each will reduce significantly which will also reduce your distortion. In the end you would not have more bass as much as far better bass.

It would be a real good idea to get an HAA calibrator involved in such a setup though...

I'm planning to go with dual subs in the future. Having 2 also helps fill in any dead spots from the one sub.

akirby wrote:I'm planning to go with dual subs in the future. Having 2 also helps fill in any dead spots from the one sub.

Or accentuate room problems.

2 of these would be sweet if you've got a real big room.....

http://www.axiomaudio.com/ep600_main.html

Well I was working on the long and complete answer but don't have the time to finish it... Probably will end up as an Audio Waveform piece...

The quick answer is room size is not the issue even if you increase the cabinet size. The benefit of the larger cabinet typically equates to a smoother response for the driver so it does not have to be pushed as hard. The only way to get a big driver to work in a cabinet that is not much bigger than the driver is to use EQ and force the driver to respond.

Ok then, 2 of these would be sweet in most rooms...

http://www.axiomaudio.com/ep600_gallery.html

My $.02

I subscribe to the division-of-labor, and wall-of-sound notion for use of subs. They are there to do the yeoman's job of getting you that last lower octave or two, allowing your glitzier main amps and speakers to do their job better. For that "wall-of-sound" I also like my fronts flanked by two subs as I have in both my HT system and my 2-channel music system. I also put a third lesser sub in the center-back of my HT system, driven by the same 80Hz low-pass mono LFE output as the front two and that really warmed up the rear image as well as adding soundtrack impact to the entire room. But I found that I had to flip the phase 180 degrees on that one so be aware of that.

I too am wary of subs that are too small to be true as in not much bigger than their driver. My main HT subs are small, have front-firing twin back-to-back driven 12s (isobaric?) driven by some immense internal power amp tailored to make sure they do what they're told. But I have multiple 12" solid masonery bricks stacked on top of each one, with non-skid rubber mat just to keep them coupled to the floor. Those bricks "walk" during a movie like Master and Commander (one walked off the edge before the rubber sticky mat) and must be checked and re-positioned. That's an example of too much power/cone excursion in too little space.

Well I was working on the long and complete answer but don't have the time to finish it.

Thanks Jim. That real world experience is a good example of what I was going to write about.

I recall reading somewhere, can't remember what it was, where someone was running their two subs out of phase with each other. He claimed that it gave a more natural feel to the Bass.

Sounds fishy to me, but wondering if anyone has heard of this. I never tested it since I'm still on one sub.