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Multiple subwoofers?

B

blind bruce

Member
I have a 20 X 30 foot carpeted listening room. I have a paradigm p1000 12incg sub between 2 paradigm p95 towers. I listen to classical music mostly and find the bass a bit thin.
My question is: would a second sub be any better than just turning up the level control on the existing sub?
How about a 15 inch sub stacked under the 12 inch sub?
These are both expensive options so I want all the information I can get before buying.
Thanks in advance,
BB
 
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I'm surprised you find those speakers don't have enough bass, even without the subwoofers, for classical. Have you tried re-positioning them?

If you're dead set on adding a second subwoofer (and I couldn't figure out which model you actually have - Paradigm made a PS1000 and a Prestige 1000SW), I'd probably try to find a sub identical to the one you've already got, and start out by putting them on the outside of the towers.

Either way, experimentation is in order to find the best position in your room, before you make any additional purchases.
 
Running two subs in stereo positioned adjacent to the mains is my preferred setup, but I get great results with my...........ahem $$$$$ single servo sub as well, it's rated within 2db down to 22hz. But again, I would certainly like to have two of those as well, my twin Dayton 12's are no match. They're rated to 25hz, but like most affordable subs no parameters are given. Don't get me wrong, I highly recommend the Dayton Sub 1200, awesome for the price, get two you won't be sorry lol.
 
Are you running the towers full range, if so I would suspect that the 3 sources, interacting with the room are canceling out some key fundamental frequencies. I doubt if you can over come those cancellations with "more power" but possibly minimize the cancellations by trying better sub placement.

Trying the Ken Kriesal idea of positioning the sub at your listening position and then "walking" the room until you find the low response sweet spot to place the sub might be helpful.
 
Is the bass thin on other music as well ?
Have you tried adjusting the phase ?
Are both subs and FS ported or sealed ?
Crossover settings of FS and sub ?
 
BTW.. I use a sealed 15 inch servo controlled Rythmik F15 subwoofer and it is very good subwoofer for music. One of the best subs for music. For HT go for their ported versions.

Rated to go down to 14hz +/- 3 dB.

Very good for Classical music :)
 
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I use two subs, works great. I run patch cords from my Yamaha 7.2 to both channels on an old HK Citation 21 pre-amp and then patch to the subs from there. Then you can use the balance and volumne control on the pre-amp to adjust your subs to your liking after setting the initial levels and crossovers on the subs themselves. I use Klipsch 12" and one 10" units with plate amps.
 
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The only real way to know whats going on with your "lack of bass" is to do a room plot.
Could be you have issues with bass cancelation etc.

By introducing more than one sub it can improve things by evening out room anomalies
if thats whats occurring.

IMO starting at the beginning "the room" is always the way to go and offten ignored.
 
Dual matching 18'' subs did not work out here. The constant fiddling of trying to get them to not bring attention to themselves wasn't worth the effort. I found it's much easier to dial in one sub in and make it disappear on the rare occasion I decide I need a bit more bottom end.
 
Don’t overlook two very important things:

1 - the theory of reciprocation (c_dk suggests above) ... put ONE sub in the listening location, play bass sweeps, crawl around the room looking for places where the sub is loudest at the lowest frequencies. Put the sub in that location and you’ll enjoy similar response at the listening position.

2 - Mutual Coupling - two subs side by side will have a greater combined output than two subs located in unique locations. Try that first - you’ll likely be racing to turn the gains DOWN.

If you do both of the above, you may find that your subs perform best located in the hallway, etc. This is putting acoustics to work for you vs utilizing aesthetically pleasing locations and trying to make that work in spite of acoustic fundamentals.

Have fun.
 
JoeESP9 said:
If your subs are dialed in properly there is no need to constantly adjust them or turn them on and off for different program material.
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That's what I'm thinkin'. And I find that two are always better than one with minimizing room modes. Especially when placed at different parts of the room.

I agree with suggestions to measure the response to assist with placement and level/xover choices.
 
Can't believe the responses to adding more or bigger subs?! Listening to classical with mains that reach 24 Hz. Move the mains out from the wall, use your sub closer to a corner and dial it in so it's seamless with the mains. It's classical music, not DJ Magic Mike for Christ's sake. Maybe your receiver/amp isn't a good match for the Paradigms?
 
Two different subs might work but you need to run the test to find out. Easier to match and skip the question from the start.
Hope you get happy with one or none. Parts left out cause no problems, if it works. Part #1 of post #13 sounds interesting.
 
damacman said:
Don’t overlook two very important things:

1 - the theory of reciprocation (c_dk suggests above) ... put ONE sub in the listening location, play bass sweeps, crawl around the room looking for places where the sub is loudest at the lowest frequencies. Put the sub in that location and you’ll enjoy similar response at the listening position.

2 - Mutual Coupling - two subs side by side will have a greater combined output than two subs located in unique locations. Try that first - you’ll likely be racing to turn the gains DOWN.

If you do both of the above, you may find that your subs perform best located in the hallway, etc. This is putting acoustics to work for you vs utilizing aesthetically pleasing locations and trying to make that work in spite of acoustic fundamentals.

Have fun.
Click to expand...

The other trick that can be done, is to place ONE sub by the technique in (1) above- then take the other- find the space in the room where the bass is still the weakest, after the first sub is put in- and put the second sub at that location of weak bass, and tune it where the bass in that location is as close to the same as it is in the listening position. There's a good chance that it will drastically even out the bass response all over the room. This is the "distributed bass" concept that Floyd Toole advocated many times in his career- and it CAN work very well, in some cases.

Regards,
Gordon.
 
I run dual subs, (Martin Logan Descents) and it took some work to get them both integrated well, without one cancelling the other at certain frequencies. I had to use REW and spend a weekend getting them set up properly. The most important thing I found in my system, was that having subs with Phase controls that were more than a 0*/ 180* toggle switch are needed. As soon as I did a sweep and had the phase of the subs set properly so that they worked together, instead of against one another, it was a night-and-day difference.

I'd suggest matching subs (to smooth out bass response across the room) and spending some time on setting up and using REW or have someone that lives in your area help you out with it. Co locating 2 subs together can just excite the room modes more, making things worse, rather than better.
 
All very good advice given. Quick summary: before spending money experiment with placement of both the main speakers and subwoofer. Good luck and let us know how you make out!
 
GordonW said:
The other trick that can be done, is to place ONE sub by the technique in (1) above- then take the other- find the space in the room where the bass is still the weakest, after the first sub is put in- and put the second sub at that location of weak bass, and tune it where the bass in that location is as close to the same as it is in the listening position. There's a good chance that it will drastically even out the bass response all over the room. This is the "distributed bass" concept that Floyd Toole advocated many times in his career- and it CAN work very well, in some cases.

Regards,
Gordon.
Click to expand...
Agreed. Go into any serious nightclub and they employ all three methods to ensure no dead zones on the dance floor. OTOH, most audio enthusiasts put subs where they look pleasing to the eye.
 
If you're really serious about evening out the bass response, the first thing you should do is find out what you have without subs. Download REW (free) and get a decent calibrated mic such as a UMIK-1, and run a plot on your system. REW also gives you a room simulator to help you find the room modes, and is invaluable to work out what is really going on. Make it the best you can before you add the sub in, so that you're not just chasing room modes and defeating the purpose of having a sub in the first place.

Once you have that, you can add the sub back in and see what it did to the room response. It may need to be moved or adjusted to optimize the response as well; sometimes by working with the one sub you may be able to get everything flat enough that another sub isn't needed. Or you may not be able to defeat all the room modes, and another sub could be helpful in filling them in. But until you measure, you're just chasing shadows; the ear isn't good enough at measuring amplitudes (especially at extreme low and high frequencies) to trust when optimizing your system when room modes are involved. You'll save a lot of time by working from a known situation rather than just moving the subs around and hoping to hit on a good spot by chance.
 
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