Performance of PSW350

Impalass

I have a PSW350 and lately i'm having issues with it at volume. When I get a movie in DSP, and with intense low frequency scenes (i.e. War of the Worlds), the sub will vibrate excessively, making a "clipping" sound. I'm currently using a Monster cable from the sub out of my Denon receiver into the left and right RCA jacks in the sub, using a Y-splitter it came with.
The rest of my speakers are RT800i front, R10 rear, CS245i center front, & CS175i center rear.
I've got all the speakers set to large and the SW to on. If I turn the SW off, the drivers in the other speakers flutter in a scary way. The only way to avoid the nasty sound is to turn the entire system down (unthinkable) or adjust the SW output down -12 db (it still does not go away, it is just reduced).
Any thoughts from those of you that know these systems better than I? Is it a connection issue, set-up issue, enclosure issue?
Thanks in advance.
Mike

unc2701

Do you have the sub cranked way up in the Denon's settings? If so, cut it back some and adjust the volume up on the the subwoofer. Otherwise, you probably just have too small of a sub for the room it's in.

Impalass

I have started with all the speaker settings at 0 db and have been trying to tweak the SW output to about -10 to -12 db. The volume setting on the sub is less than 1/2 way up.
The sound emitted during the movie is a loud clicking or rattling sound and the driver is moving wildly in and out.
In the Denon manual, it states that during DSP playback, larger signals are sent and the SW settings may need to be reduced, but I thought that 1/2 setting on both the sub and receiver weren't going to tax the systems much.
I was questioning the Monster cable via sub out connection vs. the "Polk" way of using speaker cable in and out.
Thanks.

Early B.

Impalass wrote:

The sound emitted during the movie is a loud clicking or rattling sound and the driver is moving wildly in and out.

Sounds like something's wrong with the sub. Contact Polk Customer Service.

Ron Temple

Not sure what you mean by DSP, do you mean DTS? DTS does send a full range signal. WOTW stresses most subs. There's been a ton of threads all over about it. You are probably bottoming out. The only cure is to dial it back. You should probably set your mains to small for this movie too. Lot's of sub 20hz content. Running a single XSub at -23 in my 18x14x8 room was right on the edge for me. Also, louder than ****. I doubt if the 350 hits much below 30hz, but it's trying.

Just to be sure, I'd contact Polk. Especially if it's doing it on less demanding content.

Impalass

Yeah, I did mean DTS...I must have had too much cough syrup today.
Thanks for all the good input. I'll give Polk a call and see what else to try too, just to make sure the unit is in good operating condition.

Impalass

Would any of you have suggestions on set points on the PSW350? I'm a bit confused on the low pass filter setting and the phase setting. What is the purpose of each?

jgido759

The PSW350 cannot handle the low frequencies of War Of The Worlds at reference level. I don't know of any 10" sub that can. You have 2 options, turn your master volume down or upgrade your sub.

Dr. Spec

You are badly overdriving the subwoofer. That sound is the voice coil former striking the backplate (aka "bottoming out"). Continued bottoming out will wreck the subwoofer.

Also, none of your speakers (including the RT800i) have any legitimate low bass capability, so set them all to small with an 80 Hz crossover frequency in your Denon AVR.

Use the LFE Direct input on the PSW350 (no y splitter needed), which bypasses the low pass filter. You don't need the low pass filter because you are already filtering at the receiver (digital bass mangement).

Set the phase to 0 if the subwoofer is on the front stage near the mains, and then set the subwoofer distance in the Denon.

Calibrate the entire system with Avia's Guide to HT and a sound meter. If you use DVE, there is a special technique for the subwoofer because the disc has an error so get back to us if that is the case.

Strongly consider a much larger and more powerful subwoofer to avoid bottoming, output compression, and other audible artifacts like chuffing, cone flutter, farting, etc.

Few subwoofer systems can truly handle WOTW cleanly and they are rather expensive, so don't feel too badly. Save your pennies and get ready to upgrade.