Subwoofer Enigma?

steve0202

Although I am very pleased with the sound of my audio system, I never really feel as though the subwoofer is producing the clear thunderous bass I would expect. I have the subwoofer placed in a corner of the room to the side and somewhat behind the rest of my audio system. Could this be affecting its performance? When I lean over to listen to what is coming out of the sub, it always sounds kind of muffled, not crisp pounding bass. I have set the crossover frequency to 160 so as not to double filter the sound, but what about the volume dial on the back of the sub? When I turn that up to try and create more sound out of the sub, it distorts. Even with this problem, the sound is excellent and I get many compliments on it...the RTi70's with the CSi30 are just great! I''m just trying to tweak it to perfection. Could it be my PSW250 is not good enough for my system?

gatemplin

I would guess that the problem is most likely that the 250 isn't giving you what you what, or it is in the wrong position, or both. If you decide to upgrade, then go big. I found that my 202 wasn't good enough, but only bought slightly better subs which was a waste of money.

jdhdiggs

If I'm following the polk lineage correctly, the 250 should be similar to the 202 which means it will only help boost the bass that the RTi-70's are already making. Essentially, all you are doing by setting your crossover on your reciever to direct signals to the sub is to use your subs amp instead of your recievers. IMO you are not gaining any additional material in this setup than you would if you removed the sub and set the fronts to "large" or disabling the crossover.

That being said, you would not want to replace the sub with something slightly better. If you do decide to upgrade, let some of the people on the forum know your budget, room size, and subwoofer size constraints and you'll get some good ideas.

Your positioning of the sub actually sounds ideal so I doubt that would be the issue but you could try moving it a bit to coax a bit more performance from it.

End ramble...

PolkThug

The PSW250 can only do so much.

Your placement sounds fine. I would set the sub volume knob to 12 o'clock, and set the crossover to 100hz.

If you want "loud" bass, hook the speakers up the polk way (wires from receiver --> sub -->fronts).

If you want more clarity all around, use the sub output jack on the receiver and set the fronts to small. The mids will sound much better on the Rti70's.

If you are thinking of upgrading, save your money for awhile so you can jump a few steps up the sub ladder.

Regards,
PolkThug

Turbota

Not to highjack this thread ... But >
___________________________________________

... "If you want "loud" bass, hook the speakers up the polk way (wires from receiver --> sub -->fronts).

Question: I guess it could also be hooked up like this too: (wires from receiver --> sub -->rears)

I have a pair of 70s up front and 38s in the rear (2 channel system) Is there really any problem going from the sub to the rears instead of the fronts?

Ron,

gatemplin

Steve,
After re-reading your post it seems that your sub positioning is ideal for loud bass. The 250 is probably too weak for your taste and room. As jdhdiggs already mentioned, give us your budget if you want to upgrade.

Fireman99

Turbota your answer I would say no you sub will only pick up the rear ch bass. Remember your rear ch or surround only comes as a filler the surround ch is not supose to have sound all the time.
Dan

When you set your fronts to Large and shut your sub out off. I beleive the recever sends the all the bass to the front ch from your rear ch (if set to small)

Airplay355

some people run a sub in front and one in back, so it can be done but i wouldnt take your only sub and put it in the back because of issues fireman already addressed

Turbota

Fireman99 ...

I don't have a surround system. It's a vintage Pioneer pre-amp / power amp. There are speaker outputs for 2 front and 2 rear speakers, but no fade control between the front and rears. Just balance between the right and left (equally effects the front and rears).

Just your basic 70s style 2 channel amp setup for a pair of fronts or a pair of fronts and a pair of rears.

BTW, the Rava powered-sub has speaker level inputs for 2 speakers (left and right) and 2 speaker outputs for the same .. The spec sheet says it will 'high pass' the output at 125 HZ .. first order.

It just seems like it would make no difference whether the front or rear speaker wires ran through the sub.



Ron,

Fireman99

If you are running a A/B speaker set then you are correct they Both are running like Fronts. I was refering to a 5.1 type set up.
Dan

goingganzo

the tgIII has enhanced bass it adds the lfe sigonal to the main chanel outs and you get sweet centered bass.

John K.

Steve, since the best position for a sub is usually tight to the corner, that seems fine. Also, when the receiver is handling the crossover the sub crossover control should be turned up to max to get it out of the way if the sub doesn't have a LFE type input to bypass the sub crossover; so that's okay, too. I'll mention a couple points: first, no sub is "crisp" in and of itself, low bass is inherently slow and heavy. Any crispness in say, a bass drum, is due to upper harmonics which are reproduced by the mains, not the sub. Some people might be surprised by what they'd hear if they disconnected everything but the sub and then played some music, so what you heard with your ear to the sub probably wasn't anything unusual. Also, the sub shouldn't be so loud that it's heard as a separate source; the impression should be that the sub isn't working, but that the other speakers are putting out more bass. Be that as it may, there certainly are subs that play louder and lower than the 250, if you really want more extension to be given to the mains.

Dr. Spec

Originally posted by John K.
Any crispness in say, a bass drum, is due to upper harmonics which are reproduced by the mains, not the sub. Some people might be surprised by what they'd hear if they disconnected everything but the sub and then played some music

Great point, John. The transition between the mains and the sub is very important. The mains play an equally important role in determining how things like kick drum and bass guitar will sound.

Messing around with the xo, the sub location, and the sub phase to get a smooth transition is time consuming, but worth it.