-

Jump to content



Photo
- - - - -

Would a second sub make any difference?


This topic has been archived. This means that you cannot reply to this topic.
7 replies to this topic

#1 of 8 ChuckM

ChuckM

    Stunt Coordinator

  • 132 posts
  • Join Date: Aug 12 2002

Posted December 20 2007 - 06:41 AM

I was recently offered a used Infinity PS-10 in good condition for $50. Which is a fifth of the price I paid for the PS-10 I currently own. The only thing is though I don't know if it would make any difference, positive or otherwise. The room my HT is in is somewhat small about 12x10 and the only place I could really put it is on top of the one I already own. As it is I'm pretty happy with the Infinity PS-10 . It doesn't create chest rattling base like some larger subs but it does a decent job of filling the room with bass. Would it be worth having two.

#2 of 8 John Garcia

John Garcia

    Executive Producer

  • 11,532 posts
  • Join Date: Jun 24 1999
  • Real Name:John
  • LocationNorCal

Posted December 20 2007 - 07:32 AM

On top of the one you own is actually the best place for a second one in terms of getting them to blend well in-room. What you will gain is more output at every frequency that the sub(s) produce, so yes it will help and for $50, it sounds like a good deal.
HT: Emotiva UMC-200, Emotiva XPA-3, Carnegie Acoustics CSB-1s + CSC-1, GR Research A/V-1s, Epik Empire, Oppo BDP-105, PS4, PS3,URC R-50, APC-H10, Panamax 5100 Bluejeans Cable
System Two: Marantz PM7200, Pioneer FS52s, Panasonic BD79
(stolen) : Marantz SR-8300, GR Research A/V-2s, Sony SCD-222ES SACD, Panasonic BD-65, PS3 60G (250G)

Everybody is a genius, but if you judge a fish by its ability to climb a tree, it’ll spend its whole life believing that it is stupid.” – Albert Einstein

 


#3 of 8 Philip Hamm

Philip Hamm

    Lead Actor

  • 6,885 posts
  • Join Date: Jan 23 1999

Posted December 20 2007 - 07:36 AM

How much is it worth on the market? Maybe you could buy it, sell both, and buy something else used. Posted Image

Seriously, IIRC there are sound pressure wave cancellation problems with two subs that do not exist with one. While in some situations two subs can sound good, it can be very difficult to optimize. As I understand it, putting one right on top of the other as John Garcia suggests is usually the best way to utilize such a dual-sub array.

One bigger/more powerful sub is almost always a better solution than two smaller/less powerful subs. And if you're not wanting for bass, why bother? I used a smallish sub for a long time - was I getting "Reference Level at 20Hz™"? No.* Was I getting cool bass for my house? Yes.

* While I have not measured, I think my current Infinite Baffle array and Crown amp get me pretty close to reference level at 20Hz. Posted Image
Philip Hamm
Moderator Emeritus

#4 of 8 ChuckM

ChuckM

    Stunt Coordinator

  • 132 posts
  • Join Date: Aug 12 2002

Posted December 20 2007 - 05:16 PM

How big a problem is sound wave cancellation? If sound waves are anything like mathematics for a sound wave to be canceled you must apply an inverse wave. Which would be more of a configuration problem. However, if both subs are running in phase I wouldn't think there would be much of a problem. The two subs should have excellent timber match even if one sub may be broken in more then the other. Am I wrong about this?

#5 of 8 Mendoza

Mendoza

    Agent

  • 46 posts
  • Join Date: Aug 28 2007

Posted December 20 2007 - 10:01 PM

I added a second identical 10" sub to my setup in a medium/small room (roughly 15x12) fairly recently. Each subwoofer is placed towards the front corners of the room and though I'm not a serious audiophile my system sounds much more robust now. When watching films (e.g. Transformers), the low-end is not only fuller but more transparent and less "isolated". Unless you can think of something better to spend the cash on I say go for it.

#6 of 8 Philip Hamm

Philip Hamm

    Lead Actor

  • 6,885 posts
  • Join Date: Jan 23 1999

Posted December 21 2007 - 01:08 AM

Quote:
Originally Posted by ChuckM
How big a problem is sound wave cancellation? If sound waves are anything like mathematics for a sound wave to be canceled you must apply an inverse wave. Which would be more of a configuration problem. However, if both subs are running in phase I wouldn't think there would be much of a problem. The two subs should have excellent timber match even if one sub may be broken in more then the other. Am I wrong about this?
I don't think you're wrong, I think how big a problem it is depends largely on the size of the room and where you are sitting. Low frequency sound waves are very very long, therefore if one sub is 10 feet away and the other is 6 feet away (such as different locations on the same couch), you end up with two conflicting parts of the wave hitting you at the same time causing wierd phase cancellation effects which don't happen at higher frequencies due to their different sound wave properties. At least that is how I understand it. So if the subs are right on top of each other or equadistant from the listener, you end up with no problems and big full bass. Posted Image Even with uneven long-wave phase cancellation in the room you can still end up with big full bass with two subs!
Philip Hamm
Moderator Emeritus

#7 of 8 drobbins

drobbins

    Screenwriter

  • 1,870 posts
  • Join Date: Dec 02 2004

Posted December 21 2007 - 01:50 AM

Here is a link where JBL has done a study on multisubs: http://www.harman.co...df/multsubs.pdf
In my last theater I used 2 subs. One placed front center (Sony 12" front freing) and one placed rear center (JBL 10" down freing). I used a BFD eq and was able to adjust the phase. My room was big enough (15 x 22)that there was equal distance from each sub when sitting in the "sweet spot". With this set up I could never localize where the bass was coming from and it sounded much the same in all 8 seats.
In my new theater the back row of seats is up against the wall. I also purchased a new SVS PB12-NSD. While the SVS has better oomph, especially at low frequencies, because there is only one in the front corner, I can tell where the bass is coming from. I can feel the bass stronger in the seat closest to the sub more that the seat that is furthest.
I am not an expert like others here, but I think in your size room, you wouldn't gain much. Stacking them is the best set up, but all you would gain is higher output. Then you would turn down the volume to level them off with the other speakers. I looked at the specs and your sub is rated down to 27hz. If you want more "chest rattling base", you need a sub that goes at least down to 20hz or lower. For $50 you cant go wrong buying it, but I don't think you will notice much improvement.

#8 of 8 ChuckM

ChuckM

    Stunt Coordinator

  • 132 posts
  • Join Date: Aug 12 2002

Posted December 21 2007 - 03:58 AM

Thanks guys! As always getting advice from HTF has always been my wisest choice. For 50 bucks I don't think there is much to lose. Even if it only makes the slightest impact. I don't really need chest rattling base, I have tactile transducers for that and they do respond down to 15hz. But I think with a pair I might be able to get the frequency response down to 25hz. Like most subs, I think, the PS-10 can play 20hz but it can't sustain volume at frequencies bellow 27hz. That might be different with two subs. I'll post my findings. Thanks all!