Which subwoofer should I use

[DrWho]

One more comment....

I would purchase the Plus over the Plus/2. Adding more drivers into the

same cabinet increases the max SPL by 6dB, but vastly reduces the LF

handling capability (notice that the plus digs flat below 20Hz versus

26Hz on the plus/2).

But I would still take two sub-12's over a single plus.

[mike stehr]

A pair of 15" Tumults, each in 7ft3 cabinets @16.5Hz. Power is 5.2Kw.

Room is about 18x30 and is almost completely open to the kitchen on one side.

133 db at like 6" from the port.

I don't think alot of people know what a true 120+ db at 20Hz is like in a house.

[strutter]

i think for my situation 1 sub will be all i can deal with right now. I only have 1 corner available that may be the best place for one but I'll just have to try it when i get it. really don't want to stack 2 subs. and if i got 2 for the balanced image ...i think it would be awfully difficult to calibrate as 1 would be on carpet in a corner and the other would most likely be on the hardwood without a corner.

Can you recommend some music that has a lot of bass guitar in it so i can check out the sub-12 and see just how musical it is? thats if BB will let me play my music with only the sub and no mains.

by the way my mind is not made up yet. i am still open to suggestions for my situation.

i am in the process of diagramming the area to send to SVS to see what they recommend.

[DrWho]

You really need to listen to the sub-12 with a pair of mains running...especially if you're going for musicality.

As far as music, pick something that you are familiar with. Afterall, you're going to be the one that has to listen to it []

[strutter]

this is what i was told and it sounds right to me that is why i said what i said.

A good test to see how musical a subwoofer is, is to play some good music that has an actual bass guitar in it and unplug your mains. A bad sub will go "thunk - thunk-thunk" and a good sub will go "boing-boing-boing". In other words, a musical subwoofer will have a more "round sound" and will not be "one note" or plodding. It will sound more like an instrument and less like a speaker.

but that doesn't really matter now , except as information. you see, today i noticed the sub-12 on sale at BB for $484.49 + a free $50 gift card. i thought that was a good deal. and thought what have i got to loose. it has to be better than what i have. so i played around with their floor model a bit until someone showed up. i tried to get him(he was a manager,dress shirt and tie, no blue shirt) to throw in a free monster sub cable and even after i walked away and out the door he wouldn't. so i went back after getting a bite to eat and purchased the sub. haven't set it up or anything yet, just took it out of the box.

first impression is that it looks as well made as the rest of the synergy line, not as heavy as i had thought it would be, kind of disappointed it doesn't have the black wood grain that the F-3's have. (the BB web site said it did). also, why in the world don't they put more information in their user guides?

I'll post back when i get it plugged and placed and let you know my thoughts on the sound. and of course if i have any problems i know where to come.

by the way, have you any idea if the phase should be 0 or 180 to match the rest of the synergy line? or is it just a whatever sounds best thing?

[DrWho]

it's a whatever sounds best thing...

you want the subwoofer to be in phase with your mains. You will notice

when it isn't in phase because you will have cancellation of the

frequencies in the crossover region. The best way to set it is to have

a friend flip the switch back and forth while you sit in your chair

listening to some bass heavy music...go with the setting that sounds

the loudest (and back down on the gain if you feel that its too loud).

Since we're on the subject, I thought I'd mention that a lot of mains

are almost 90 degrees out of phase in the typical 80Hz crossover

region. The cornwall and heresy for example are both 90 degrees out of

phase at 70Hz. This brings up an interesting point that a 180 degree

phase switch on a subwoofer would pretty much have no audible

difference between positions! (as you will still be 90 degrees out of

phase either direction). In a way I suppose it's a good thing because

it helps dummy proof setup. Also, the subwoofer and mains won't be

summing their signal either so you'll have to boost the sub's gain by

3dB to compensate.

[strutter]

i tried flipping the switch by myself, maybe something was lost during my movement from chair to sub, but i couldn't tell a difference. I'll get help later.

so on one thats 90 degree out of phase, the switch (0 or 180)is useless. nothing can be done?

also , i just set it up by ear (no spl meter) with music. I don't have much to compare it to but i think i have to agree that this is a musical sub. i played a Gene Simmons bass guitar solo, iron maiden, and some rap. sounded very good. except for the rattle of nick knacks. my son walked outside, across the road into the neighbors yard(about 75 yards) he said he could still hear it. I fear for the side neighbors, the houses are only about 30 feet apart . gain is set just a little past 12 o'clock. receiver volume at -10 (gotta love it loud) have not watched a movie with it yet. maybe tonight I'll pop in war of the worlds. it's got some ungodly low frequencies in it.

as far as set up. on the receiver i tried with the mains set on small and large. i tried with the sub set to normal and plus mains.and all variations of the previous. as far as for music i think i like it best with mains at large and plus mains. but then again i may have to move the sub around some and play with the gain some. i tried lowering the sub volume on the receiver in 1 decibel increments from -0 to off. thinking this would free up some power in the receiver and just let the sub amp do all the work. dang if i didn't learn something. off really means off ,as in sub no sound. so i left it at -0 as well as the mains.

"Also, the sub woofer and mains won't be summing their signal either so you'll have to boost the sub's gain by 3dB to compensate."

please explain, do you mean sub + main = 3db less. or are you assuming i would set the receiver to sub normal, not plus mains. sub normal sends everything below the crossover to the sub only. plus main includes those frequencies in the mains as well.

well .....got to go play some more.

[DrWho]

The subwoofer setup will probably drive you mad for a few weeks...but that's normal []

The difference between the subwoofer being LFE+Main and just ON make no

difference for normal music listening with your mains set to large. At

least I think that's the case. However, LFE+Main will route the LFE

material to both your sub and your mains when watching a movie. You'll notice that you

can't select LFE+Main if you set your mains to small.

Whenever a crossover is used, it's not a brick wall where all

frequencies above go to one speaker and all frequencies below go to

another speaker. A crossover instead gradually rolls of the frequency

response (rolls off the lows for the HF speaker and rolls off the highs

for the LF speaker)...so there is a lot of overlap of the same

frequency being played by both speakers. It gets a bit complicated to

think about it in terms of the logarithmic dB scale, but it works to

just remember that two speakers playing the same frequency at the same

volume will result in a 3dB boost in the overall volume. In other

words, an 80Hz crossover makes both the sub and the mains -3dB at 80Hz.

But since both speakers are playing the same material at the same

volume, it sums to a total of -0dB and you have a perfectly flat

frequency response (at least in theory).

However, all that is assuming the speakers are in phase. If they are

out of phase, then you get an infinite reduction in volume. If they are

90 degrees out of phase, then you get no interaction whatsoever...which

means the -3dB from your crossover isn't getting corrected by the

drivers overlapping in frequency and therefore you don't get a

perfectly flat response in the 80Hz region. But this isn't a big deal

because you can just boost the gain of the sub by 3dB to obtain a flat

response...which will then also boost the volume at all frequencies

below 80Hz. The end result is an increase in the apparent low end of

the subwoofer. (If the subwoofer was flat down to 20Hz, then 20Hz would

now be 3dB louder than at 80Hz).

It's also not a big deal because our rooms have a +-6dB impact on the

frequency response (if not more) which means +-3dB doesn't make much of

a difference in that window.

[strutter]

yes, i fear i will soon go mad.......

I'm going to spend some time researching bass management. don't know if the info i get will lessen the madness or propagate it.

because i have never had a real subwoofer i really don't know what to listen for.

how will i know when it is right?

what does it sound like when a sub is over extending or bottoming out?

BTW, war of the worlds was awesome last night.....the wife kept looking at me and smiling...it's a totally different experience when you can feel the movie. it's the first time i could tell she was getting a lot of enjoyment out of our audio equipment.

she liked it when i went to surround sound , even though she says she cant hear the sound move from speaker to speaker or hear anything coming from the rear unless she concentrates on hearing it. she says with the surround on she can hear the dialog more clearly. But the sub had her tickled to death. best purchase i have ever made in my opinion.

[DrWho]

With your synergy sub, here is what I would do:

Set the crossover on your reciever to 80Hz and bypass the crossover on

the back of the subwoofer (put it in LFE mode if it has a switch. If

not, then set the crossover to the highest setting possible). Set the

phase on the sub to 0. Set all the speakers except the mains to small.

Go ahead and run LFE+Mains (which means mains are set to large). Now

bust out an SPL meter and play the test tones on your reciever...make

all the speakers (including the sub) match in volume. If you don't have

an SPL meter, then do your best to do it by ear, or go purchase one.

They aren't that expensive and take a ton of the guess work out.

Now go listen to some music and give it some time before you go trying

to change anything else. If you don't know what a particular setting

does, then go check out the owner's manuals or come online and ask us

(I'm sure more than one person is wondering the same thing). Do not

change a setting until you know what it does (not because you might

break something, but to keep you from shooting in the dark). Before

making a change, try to anticipate the difference it will make; then

make the change - did the sound change how you anticipated? If it did,

then great you have achieved a slight improvement. If not, then switch

back and forth to train your ears on the difference. And lastly, change

only one thing at a time (so that you know exactly what is doing what).

Keep in mind that after setting the relative volumes correctly, that

you are already 80% of the way there. If you don't have much experience

with quality subwoofer systems then you probably won't notice much

difference with the last 20%. Nothing wrong there, you'll just have to

train your ears. Heck, I've been dialing in crossovers on all sorts of

systems for many years now and I still find myself tweaking, wondering

if I can't step it up a notch. In the end I usually just end up

reverting back to the simplest method.

At first a lot of people run their subs way too hot. You'll know it's

dialed in correctly when you don't know if the sub is playing (only

when listening to music). But when you turn the subwoofer off, you

should be able to notice a huge difference in the sound (it'll feel

like the foundation just dropped out). And then when you turn it on

again, the foundation comes back, but you don't really notice that it's

playing.

[steamer]

Here is one to check out,might fit your your price range.

The Ear would be able to tell you if this is a good fit for your situation.

I think it would be,got a coulpe of them! with the same EQ/INTEGRATOR outboard and an outboard amp(mine are passive,this one has the amp/integrator onboard)

Greg

http://cgi.ebay.com/Bag-End-Infrasub-18-Powered-Subwoofer-New-Condition_W0QQitemZ7375098339QQcategoryZ47095QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

[strutter]

thanks for the info DrWho.

Will do.

Gotta get an SPL meter.. its on my list. my understanding is to get the radio shack analog one, not the digital one.

found some other useful info on the audioholics web site.

again , thanks