One big subwoofer or two weaker subwoofers?


Hello:

Do you think that, for stereo, is better to have a bigger subwoofer or a pair of weaker ones?

For example, should it better to have a pair of Rel Strata III (or the new Strata 5) or a single Stadium III?

Thank you
mavilla
Greg: My Dad's system is actually quite solid down to 35 Hz and rolls off below that. Given that he doesn't listen to pipe organ music or electronica, he'll simply have to get used to "natural" sounding bass. It may take some time, but after living with stupendously bloated "thud" for years on end, and thinking it was both "good" and "extended", it may be tough for him to deal with initially. As i've already commented though, he is well aware of the phenomenal increase in bass resolution and transient response, so i'm thinking that there is hope : )

As far as the sub goes, that will be used for HT purposes only. This specific model was rated as being -1.5 dB down at 25 Hz and is quite large. Due to using this strictly for special effects on movies, placement of the sub becomes less critical. This is in comparison to if the sub was used for stereo purposes, which would require some semblance of low frequency imaging. The speakers that he's running for mains are actually too large for the given installation in my opinion. Adding two large sub-woofers with the requisite box size required for good performance would be too much for this room and there just isn't enough space to do so. Given that his mains already have an 8" and 10" per cabinet that share the low frequency load, he's not "hurting" in this regard.

Besides all of that, i'm paying for the sub, amp and cabling, so he can't complain about "only having one sub" : )

El: The mids, tweeters and woofers that my Brother is using are Morel drivers. Given that Morel purchased technology from Dynaudio, one can see the similarities in driver design.

Having said that, i agree with your assessment. That is, even with minimal mass and big motors, these drivers just don't move air / respond like a "big boy" can. This is why i've got six 12's, four 10's, six 8's in my HT system and eight 12's in my main two channel system. Even with all of that, i can hear others saying "What ?!?!?! NO 15's, 18's or 21's ????" : )

UncleJeff: If you do some research, i think that you'll find that you'll have better luck building a sub from a kit than anything that you can buy at a brick and mortar shop for anywhere near the same amount of money. Having said that, most sub kits are PHENOMENALLY easy to put together, so don't let a lack of mechanical / electrical aptitude scare you away from attempting such a project. Sean
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PS... The pair of subs that i've got lined up for my next "project" make use of a single 12" and two 15's in large, low Q sealed cabinets. I may use these with my Ohm F's, which should help increase max spl and clean up their transient response a bit. Obviously, active crossovers would be used since passive's do horrible things to the amplifier / speaker interphase : )
Sean..What no 30 inch EV30W? Back in the old days one would install one of these monsters in the ceiling, vented to the attic. Hartley 18 inchers were second best.

If you are looking for 15" subwoofers, check out the JBL SUB 1500 drivers that Parts Express is selling at a good price. I just got three to replace the JBL LE15 that I have been using (which are good, but not really designed for the SW application). I am impressed.
El: First of all, i'm shooting for the 64" drivers that EV used to make. Who wants those "puny" 30 inch EV's when you can have the "BIG boy" : )

The JBL's at Parts Express are designed to be used in a vented system. If i was going to spend that much money on a driver, i would use one that was more optimally suited for a sealed design.

Funny that you should mention them though as the 15" that i'm using actually is a JBL. Some folks consider it the best ( or one of the best ) "audiophile type" woofers that JBL ever made. It is a model 2235 and both the driver and the cabinet that it came in are in great shape.

For those that might remember these, it is a good sized Sumo Samson subwoofer that i purchased for $40 ( yes, FOURTY ) locally. Factory specs showed a response of 25 Hz to 125 Hz +/- .5 dB ( yes, HALF a dB ), but i don't believe that one bit. This is a vented design using TWO huge ( 4" x 18.5" ) ports. Obviously, this thing was designed to move a LOT of air at low frequencies and was optimized for high spl's. Due to that tuning though, i'm quite certain that it would lack "finesse", both at lower volumes and for music use. Given that this will be strictly used for the LFE channel when watching movies, it should work out quite well. Either way, it will be FAR from stock when i'm done with it.

Given the price and the driver involved, there was NO way that i was going to pass up a deal like this. The only bad part about the whole transaction was trying to get this behemoth into a hatchback by myself. The cabinet is appr 30" x 24" x 19" and weighs 150 lbs. Needless to say, i DID break a sweat :( Sean
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You guys have to check out the Adire Tumult.I currently use two,each in a 2.5 cu.ft. cabinet.Since the F3 is about 27hz in that small of a cabinet I am going to buy two more and run a Marchand bassis to reshape the curve flat down to about F3 of 16hz.850 watt mono adcoms on each and .....oh boy I gotta go to bed.
Sean...Those JBL 1500 seem to work well in my sealed enclosures, but then they are 7.5 cubic feet. How would I know that these drivers are designed for vented use, other than the FS = 24 which is higher than some but still well below the typical 15" Prosound driver?

The only thing I can cite to match your EV 64" thing is the vibration machine that we use to test our missile GS. This machine really is a huge loudspeaker, and has a "voice coil" four feet (yes feet) in diameter, and shakes two hundred pound objects at awesome levels. Interestingly, its frequency response goes a lot higher than most subwoofers. We use it up to 1000 Hz or so (but not with flat response). I don't know what the power amp is...it's old enough to be some kind of tubes. Maybe amplidyne. I will find out. The drive is a closed-loop servo using accelerometers mounted on the test fixture (a la Velodyne).