Home Theater Forum  ›  Forums  ›  Home Theater  ›  Basics  ›  different subs?
Forum Nav More Forums | All New Posts | New Thread

different subs?

#1
Rating: 0
11/26/08 at 5:48pm
  • Joined: November 2008
  • Post Count: 5
I own an Energy ES-12 12" powered subwoofer and was considering getting another one for my home theatre. I was offered an Energy EXLS 12 subwoofer for a reasonable price but was worried that two different subs paired together might not be a good idea. Thoughts? My receiver has a single "sub out (RCA)" connection

Also, my room is approximately 17x19. No sound escapes the room but I as wondering, would acoustic panelling imrpove the quality of sound?
Export to Wiki
#2
Rating: 0
11/27/08 at 1:42am
  • Joined: July 1997
  • Location: Amsterdam, Holland
  • Post Count: 16,286

Re: different subs?

Hello Sunny,

Welcome to the forum.

Generally speaking, it's a bit tricky to use two speaker boxes to produce sound from the same source. The dreaded word is: interference. Sound travels at a certain speed and the result could be that the same wave that is sent by one of the speakers lowers the air pressure at the place of the other speaker at the exact time the other speaker is trying to increase the pressure. It is frequency dependent and has bad effects on the quality of the sound.


That said: the lowest bass waves are generally very long. More than several feet, so in your room they will not exhibit a wave form: the subs will just higher or lower the pressure in your whole room at any given moment.

Now interference is still possible, when the subs are of a different design. But many people greatly enhance their deep bass reproduction by having to (or even more) subs in one room.
So, you are proposing to add another sub of the same brand: that could be fine. You must take extreme care to drive them "in phase" (make sure to connect the same receiver output wire to the poles marked "+" or "-" on both subs). If you don't, one sub will be increasing the pressure in your room (cone moves "out") at the exact moments the other lowers it by moving in, and vice versa.
In case of doubt listen carefully if the bass increases if you add a second sub's sound.

Preferably, place both subs close together.

Another option would be to find out how much it costs to replace your existing sub by an even bigger one (and bigger than the one you consider to add). It might save you some headaches when placing, but it will empty out your wallet a bit more.


Good luck with your decision!


Cees
HTF Rules (uhm ... and has Rules)
Export to Wiki
#3
Rating: 0
11/27/08 at 6:52pm
  • Joined: November 2008
  • Post Count: 5

Re: different subs?

Thanks for the advice.

Can you offer me any words of wisdom on my second question about acoustic panelling?

Thanks again!
Export to Wiki
#4
Rating: 0
11/28/08 at 7:16am
  • Joined: July 1997
  • Location: Amsterdam, Holland
  • Post Count: 16,286

Re: different subs?

Sunny,

If it's not acoustic insulation you're after, the sound inside the room could be improved by acoustic panelling if one or more of your walls (and floor and ceiling) are hard sound reflecting surfaces. Often, there's a carpet on the floor, so that one doesn't need to be dealt with and the ceiling (if not terribly bad) isn't as sensitive.
For a moment you can also forget about the front wall, unless it's absolutely terrible (see below).


That leaves you with the two side-walls and the back. If those are hard, smooth surfaces (test: stand 5 feet away from each of them, facing the wall and say words like "pet" and "crook" and "hello" and "ha, ha" aloud; you should not be getting the feeling you really hear your own voice back from that wall), then yes, it may improve your general sound quality if you cover large parts of them with some fabric.


Cees
HTF Rules (uhm ... and has Rules)
Export to Wiki
#5
Rating: 0
11/28/08 at 6:22pm
  • Joined: November 2008
  • Post Count: 5

Re: different subs?

Thanks! You've been a great help.
Export to Wiki
Forum Nav More Forums | All New Posts | New Thread