2 subwoofers v.s. 1 subwoofer

In my set up i use one MJ acoustics reference one subwoofer. This sub can go down to 10 Hz and it works flawless in my Hauptwerk setup.
It's already a bit older sub and often on the second hand market i can buy these great musical subs very reasonably priced. Is it worth to ad a second identical sub to create true stereo front channels also for the lower frequencys.
Does it have advantages for standing waves elimination? or other advantages like more pressure in the subbas area.
Any suggestions? experiences ?

Regards Jan

A second sub will not help the stereo image since those low frequencies are essentially not directional.
I think a second one being different and having a different frequency result would cause all sorts of peaks and nulls with respect to the other one. At least that's my guess.

2 subs can help the stereo image a bit if your mains are not full range and the crossover is above 60Hz or so. If your mains are full range and the sub crossover is a 40 Hz or below, I agree that 2 subs won't be noticeable and can be VERY hard to set up in a way that you don't get cancelling or reinforcing nodes where it sounds worse than a single sub.

If you just need MORE POWER, you could put 2 subs right next to each other -- but you'd need a very large room to require that.

There would be reduced cone excursions with two subs which could reduce distortion a lot if you are listening at high levels. There will be a slightly smoother response as pedal samples, like higher pitched samples, will vary with one channel stronger that another for different notes. I'd thing the standing wave issue would not be much better or worse in most cases. On balance I don't see a lot of justification for the added expense unless the price for the duplicate unit on eBay is really attractive.

If you just need MORE POWER, you could put 2 subs right next to each other -- but you'd need a very large room to require that.

I second that emotion. Place them right together, doubles the output.
Also provides a little more very low frequency output.

Hello,

I use two large RTR-25 full range speakers in my HW multiple speaker system. These big guys have a 25" subwoofer each. They reproduce very big 32' pitches.

Here are two reasons I like to have the two subs.:

I can route the subbass 16' and diapason 16' (etc.) to different subs. When using both Pedal ranks together the sound is cleaner than when all lows go through the same speakers. I can separate the low Pedal ranks to right and left in theatre organs---mainly an improvement in clarity.

The other thing I've found to be better with two subs is with a few organs that have a resultant 32' rank, where the 16' rank is separate from the 10-2/3' rank. I was amazed at how huge the sound of this combination was on the Litomysl organ. The resultant pitch is heard as it mixes in the room air, rather than electronically. Really a very full and huge sound!

Leo Chris.

I finally got my two Sonotube subs working. It takes me forever to complete a project. Now I just need to figure out what to cover the sonotubes with.

Anyway I did alot of reading on subwoofers before building these and found that more than one sub is recommended to help control standing waves etc. My subs work great and I'm pleased with the results of two. I eventually plan to build two more to put in the rear corners for the surround. I have a fairly large room. The subs stand 6 1/2' tall and are 24" in dia. with 18" drivers. They really shake things down to 16 Hz no problem. Only problem is my Behringer amplifier has a loud fan. I plan to locate the amp in the basement. At some point I'll try and add a couple pictures.

Eric

In my set up i use one MJ acoustics reference one subwoofer. This sub can go down to 10 Hz and it works flawless in my Hauptwerk setup.
It's already a bit older sub and often on the second hand market i can buy these great musical subs very reasonably priced. Is it worth to ad a second identical sub to create true stereo front channels also for the lower frequencys.
Does it have advantages for standing waves elimination? or other advantages like more pressure in the subbas area.
Any suggestions? experiences ?

Regards Jan

[quote="Eric Sagmuller"]I finally got my two Sonotube subs working. It takes me forever to complete a project. Now I just need to figure out what to cover the sonotubes with.

Anyway I did alot of reading on subwoofers before building these and found that more than one sub is recommended to help control standing waves etc. My subs work great and I'm pleased with the results of two. I eventually plan to build two more to put in the rear corners for the surround. I have a fairly large room. The subs stand 6 1/2' tall and are 24" in dia. with 18" drivers. They really shake things down to 16 Hz no problem. Only problem is my Behringer amplifier has a loud fan. I plan to locate the amp in the basement. At some point I'll try and add a couple pictures.

Eric-quote]



I would love to see some pics and hear more about your plans on the build of these!

~Scott

Hi Scott,

Sorry, I just haven't had the time to figure out how to host pictures to link to the forum. I have a way to do it through work, but it's something I would need to figure out. I'll try and get some info. together in the near future. Thanks for the interest. If you have some specific questions, I could try and answer them.

Eric

Hi Eric,

I just wondered about the basic construction. Did you mount the driver in one end and leave the other open or closed, ported, upfiring, downfiring, that sort of stuff?

Thanks,
~Scott

Hi Eric,

I just wondered about the basic construction. Did you mount the driver in one end and leave the other open or closed, ported, upfiring, downfiring, that sort of stuff?

Thanks,
~Scott

Scott,

The driver is at the bottom and downfiring, tube is vertical. There is an 8" port on the top side tuned to 15hz.

Eric

Just to throw my 2 cents worth in here. First, I'm on the same page as Leo on this one. I recently added a second sub I'm routing anything 8' and 16' on manuals to. Can't say anything concerning the standing wave part but I have for sure noticed a much smoother / blended overall delivery of the lower end sound, no breaks or what at one time sounded more like abrupt transitions from the pedal to the manuals ranks. Technically speaking, I think a sub dedicated to every manual containing 8' and 16' would be more ideal, but this depends greatly on how many channels you're working with and how you route things.

I know Leo is up to about 80 channels now (maybe more?). For now with my 8 channels I'm at least a two sub believer, but for Leo?

Marc

I was looking at Steve Deckerts (sp) website, he is the one that invented the Housewrecker subwoofer. It is called Decware. He has some intriguing ideas!

Some that I was particularly taken by were a subwoofer called the Imperial SO, for Subwoofer Only. This one is large, maybe 5 feet tall, but extremely efficient. With the right 15" driver, he proposes that it eliminates frequencies over (about) 200 Hz, so it can be run WITHOUT a crossover! Also, it is supposed to dig deep, like to 15 Hz, and efficient, like 96db! So it can be powered by a 2 watt tube amp! On the website, they said that they would pick up frequencies from speakers placed IN FRONT of them and resonate the base, WITHOUT AN AMP HOOKED UP!

The other one is a full-range, open baffle design that is supposed to give an extremely wide soundstage. He has modified drivers that have eliminated the mid range "shout", and thus have a smooth response throughout the bandwidth. This particular speaker design includes an ingenious resonator cavity which accentuates the bass response and gives the open baffle design the depth of a closed cabinet, as well as response down to the mid 40 Hz range.

With these 2 crossover-less speakers, being allowed to naturally 'roll-off', one taking over where the other leaves off WITHOUT the interference of a crossover. I am VERY intrigued by this idea!!!

~Scott

I agree that going with a second sub, that is not identical to the first sub, sounds very risky.

This topic reminds me of the time when Walt Strony had finished voicing the Allen TO5 (with two large bass cabinets) located here in San Diego. We all sat around as he tweaked the bass channel(s). Not sure if it has one or two sub channels, but it definitely had two large sub cabinets. Although we could hear the bass, we could not feel it at all. When he turned it up so we could feel it, it was way too loud. At this point, he suggested adding a third sub to the room. He told me that subs should never have to work that hard in a room and it is best to have each bass speaker at half what the other speakers are producing. His advice sounded a little odd, but I kept my apprension to myself.

When the third sub was added to the system and regulated with everything else, it finally sounded and felt powerful. The mix was just right throughout the entire range of bass notes. It balenced well with the other divisions. And you could feel the lower octave of 16s in your body no matter where you sat in the room.

The third sub made a huge difference in the overall sound experience. The whole organ finally sounded majestic. What a lesson I learned that day.

Ted Williamson

I was looking at Steve Deckerts (sp) website, he is the one that invented the Housewrecker subwoofer. It is called Decware. He has some intriguing ideas!

With these 2 crossover-less speakers, being allowed to naturally 'roll-off', one taking over where the other leaves off WITHOUT the interference of a crossover. I am VERY intrigued by this idea!!!

~Scott

That's fine if the signal feeding the amp doesn't have alot of frequencies fed it that are out of the speaker's response band. Any speaker will roll off at a certain frequency, and as long as it isn't fed this out of band material, it doesn't need a crossover.

Eric