PSW450 Subwoofer Problems

cqlink

After hearing a friends' PSW 450 sub, I had to have one. Problem is I had to turn the back volume knob up to 80% of the range to get decent bass. I also heard loud cracks or pops when played at loud volume. I normally don't play DVDs loud but the Matrix is an exception. The folks at Polk were courteous as usual but they wanted me to send in the 10" woofer. It doesn't appear to be blown, however. Anyone have any ideas?

fireshoes

How do you have your sub wired?

cqlink

Initially, I used a single RCA cable from the subwoofer jack from the back of a Denon 2802 to the LFE input of the PSW450. This is called "hook-up option #2" in the Polk manual. As mentioned, I increased volume on "Pvt. Ryan," and "Matrix" and heard the pop/crack. It didn't sound like a blown woofer. I tried "hook-up option #1" next. That is Lt. & Rt. speaker output from the receiver to the sub and then out of the sub to the speakers. I still had the cracks and pops at loud volume. In both cases, I had to turn the volume knob to the 4pm position to get decent bass. The Polk tech said I shouldn't have to go past the 12 o'clock position. After reading some threads here, I went back to the single RCA cable hook-up and placed the sub in other parts of the room for comparison. Bass seemed to inprove marginally but I'm afraid to crank it up. Thanks for your feedback. Any ideads?

mantis

OK,
the Denon avr2802 has low voltage out from LFE.It's about 6 volt's at 0db setting which its reference.You should setup your whole system with a SPl meter if you didn't from to get go.Placement is also an issue to get best performance.Most of the time,if you have a corner in the front of your room,that is a great place to start.Keep it out of the corner about 2 feet from the back wall and 2 to 3 feet from the side.Use the LFE out to the LFE in on your sub,it bipasses the internal crossover.Use good quality cable to run the sub.Now if you set the sub up to 75db with the rest of the system,you shuld have great performance out of that sub.If your room is very large,then you might need a bigger sub like the 650.Popping and clicking isn't normal for that sub,you should return it where you bought it and get another one,it sound's like somethings wrong.
I own the Denon 3801 and the Psw450 and have awesome performance.I like the combo.I never turned my sub up to 4 o clock the highest it ever got was 12 oclock.I set it at 12 oclock and then tailor it in the Denon,but if it goes more then 3 or 4 db.I try to set the sub closer to 0db in the receiver.It never got past 12 oclock.
Just make sure you break in your new sub before you start running it hard.
Dan

Indrama

Just a thought,

I had a similar encounter with my 450, I was always getting great response with it shook everything in the house, then I got the CS1000, so to make that sound great I changed the setting on my receiver so that the center channel would be set to LARGE, well did that change everything, by setting the center to LARGE it also changed the front's to LARGE and activated the "Bass Management Circuit". The sound it produced was allot like you described, when I changed it back to small, BOOOM!!! there was my bass again, maybe that will help. good luck.

Billm57

I get popping on occasion on my PSW350..does that indicate something is wrong hardware wise? I dont get it regualrly..just on occasion..some parts of Private Ryan and Phantom Menase

dylan

For what it's worth... I had the same popping problem on my 350... I think it's the DVD sending too low a signal that the 350 just can't reproduce. You'll probably only notice it on heavy duty LFE spots, like:
chest punch in the Lobby Shooting spree in The Matrix & the explosion when the helicopter hits the building, some of the explosions in Saving Private Ryan, dino's fighting in Jurassic Park III, and basically the whole Phantom Menace (especially the pod races). I think PM finally killed my driver... it ended up making a wimpy rattle during bass sequences... and I had to have Polk replace it. In my experience, the infrequent pops didn't mean damage at that point, but did eventually when the rattling started.
I did find (if you're using the speaker-level connection) lowering the crossover point helped out quite a bit, and if using the LFE, I could turn the volume to no more than 1'ish.

I wish I had a better answer, but I ended up getting the psw650 because it kept making me nervous... I really liked the 350 otherwise, enough to get the 650. I think Polk doesn't make the most earth-shattering subs, but very musical ones. I love the 650.

cqlink

I think your call is closer to what's happening. That's why I mentioned to Polk I didn't think the woofer was blown -- yet! I noticed the pops and cracks on certain DVD scenes as well

My room isn't exceptionally large, that's why I went with the 450. I'm going to ask Polk if they'll take this one back and let me upgrade to the 650. If they don't agree, it looks like I'm going to have to start sending parts back and forth. This is bad because they are in CA and I'm in MI.

Thanks to all for the feedback.

juice21

i think this 'popping' people are experiencing, is actually clipping of the woofer. i had this problem on my last subwoofer, in both the matrix scenes mentioned, as well as the opening bass in toy story 2, and a few other movies, i would have to lower the sub's output to avoid this problem. in doing so though, the bass response throughout the rest of the movie was sub par. upgrading to the HSU's, i have not had anything like this, and i play these at levels that far superceed what the last sub could handle. in my case, it was simply the sub that could not handle the bass frequencies that i wanted to achieve, hence, my only option was to upgrade to a higher quality sub that could handle what i wanted to throw at it. i am not saying that the psw450 is not a quality sub, but in your case you may need something a little better to get the bass levels you want to acheive. (unless i am wrong, and there is something damaged with your sub)

Dr. Spec

There is no doubt running a sub too hard will eventually destroy it. I'm very conservative about how hard I run my subs, exactly for the reasons you guys mentioned - certain DVD's just blow out the bass. PM, Matrix, U571.

I have a 12x18 room, and I run two stacked PSW350's off the LFE with a Y-splitter. Sub volume is set just shy of 12:00 for both of them. Sub setting on the receiver is +1db. Max volume I run on the receiver (100 WPC RMS 20-20K x 5) is -25 db. At this volume, the subs REALLY shake the room on these scenes and neither is working too hard, with loads of dynamic headroom and cone excursion left.

Unless you really need the last half of the lowest octave, two 350's have more power and dynamic headroom than one 650.

I'm a firm believer in too much sub running easy vs. too little sub running close to max - the latter is a recipe for disaster.

I also heard the HSU subs really kick it out.....

Spec

juice21

Originally posted by Dr. Spec


I also heard the HSU subs really kick it out.....

Spec

they do! i get to hear it every nite...:D

Billm57

Originally posted by dylan
For what it's worth... I had the same popping problem on my 350... I think it's the DVD sending too low a signal that the 350 just can't reproduce. You'll probably only notice it on heavy duty LFE spots, like:
chest punch in the Lobby Shooting spree in The Matrix & the explosion when the helicopter hits the building, some of the explosions in Saving Private Ryan, dino's fighting in Jurassic Park III, and basically the whole Phantom Menace (especially the pod races). I think PM finally killed my driver... it ended up making a wimpy rattle during bass sequences... and I had to have Polk replace it. In my experience, the infrequent pops didn't mean damage at that point, but did eventually when the rattling started.
I did find (if you're using the speaker-level connection) lowering the crossover point helped out quite a bit, and if using the LFE, I could turn the volume to no more than 1'ish.

I wish I had a better answer, but I ended up getting the psw650 because it kept making me nervous... I really liked the 350 otherwise, enough to get the 650. I think Polk doesn't make the most earth-shattering subs, but very musical ones. I love the 650.

Yea-I even called Polk tech support before I bought the 350 and asked if I would be better off with the 450 or 650 and they said since I was buying the RM6600's that the 350 would be the best bet..I knew i should have went with the larger one as the popping is not good..it should handle any dvd I put on on in my eyes

yater

I have the popping problem with my PSW350. WIll hooking it up through LFE help IF SO?

How do I hook it up to LFE Input what kind of cord do i have to buy and can I just hook it up through the subwoofer output on my reciver.

ALSO Does Polk take trade ins on subwoofers if I upgrade.

Thanks

Email Me at yater@bigfoot.com or you can reply on here

robertgray

My 350 pops (more like rifle shots) with effects intensive DVDs (Jurassic 3, Phantom Menace, Behind Enemy Lines). Called Polk just this morning and learned that I am asking too much from the sub. The techie was great and gave me a long technical explanation for what was happening inside the sub to give the pops. I was driving to work and talking on the cell and could not write down what was said. I am going to send this post to the moderator to see if Polk can post the same technical explanation that I was given.

Today is day 30 for my Circuit City purchase. I stopped by the store and had the manager approve a one week extension for a return. This week I intend to experiment with receiver/sub settings (Onkyo TX-SR600) to see if I can get the bass I want without having to push the sub limits. If not, I will return the 350 and get a 450.

dlew308

I listened to the psw350 at different stores with the psw450. I fell in love w/ the psw450.
I'm just happy it sounded as well as it did in the stores. The psw450 is worth it over the psw350

fort

For what the psw450 is worth, just buy the HSU VTF-2. You won't regret it. No popping problems even with U-571, Matrix, Toy Story 2, etc. Flat response down to 25 Hz (in maximum extension mode) and very musical too. Don't get me wrong. My speakers are all Polk, except for the sub.

scottvamp

Called Polk just this morning and learned that I am asking too much from the sub.

I am sure that this is the simple answer to alot of the "popping"
*during really heavy low freq. dvd soundtracks* hello
Must turn down sub. Must understand bass management. Must buy larger more powerful sub.
"I'm giving it all she's got Captian"
PSW1200 funny never heard no popping. Heeee!!!! Heee!!!!
Ya I'm a smartass!!!

jeberhart

Hey Dr. Spec,

Where did you get your Y-splitter for LFE out to subs? I have a Denon AVR 3801 and a Pok 450 sub, and I've been thinking of adding another sub. Also, since the 450s are self-amplified, shouldn't there be zero problems with the AVR running them? Does the Y splitter just send an identical signal to both subs? Does the Y splitter degrade the signal at all?

jeberhart

I'd be willing to bet there is something wrong with your sub, or something going awry in setup. I run my 450 awfully hard, and I've cranked my system during "Saving Pvt. Ryan," "U-571" and a lot of other noisy DVDs, and my sub has never popped and cracked. ONE TIME, though, I was messing around with the volume on the back, and I tilted the sub forward to get to it because the room was pretty dimly lit and I couldn't see what the hell I was doing. Bad, bad idea. Two or three enormously loud cracking noises came out of the sub, and I freaked. I put it back down on the floor, it sounded fine, but I was so wigged out that I immediately called Polk. The tech I spoke to said it was probably the LFE connection moving around, or MAYBE having the box tilted, but he really didn't know.

I DO know that I've NEVER had to turn my volume knob on the 450 up to 80 percent -- not even close. I like ALOT of bass, and mine right now is set about 1 o'clock, or a bit over 50 percent, and it's too loud for most other people who hear my system.

I wonder if your problem actually isn't in the amplifier section. The reason I say this is I used to play bass guitar, and I had a hellacious Crate head unit coupled to a 2x15 speaker enclosure. After about three years of hard playing, during which I admittedly abused the thing by also running a synth through it at times, I turned it on one day and had almost no output. It would play, but the volume was very low. The speakers were fine, according to the repair people, but I had toasted the amp. Anyway, something to consider.

Dr. Spec

Jeberhart:

I use Monster Cable subwoofer cables, and a Monster Cable Y-Splitter. I bought the Y-splitter at CC for $15. It's the same high quality construction as the sub cables, so there is no degradation of signal quality.

Splitting the signal will not result in a lower voltage as long as the tiny preamp in the LFE jack has enough juice (i.e., milliamps) to power both jacks at the same voltage, which it easily does, at least on my Kenwood.

I tested the LFE output with a voltmeter with the 44Hz test tone for the subs. The voltage output at both split jacks was identical to the voltage output from just one dedicated jack.

There is a limit as to how many times the LFE signal can be split before you exceed the current capability of the LFE preamp, but you probably won't reach that limit in a typical HT set-up.

While I have not checked it, I imagine you could probably split the LFE signal several times before you started to see a drop in the LFE signal voltage.

If you do decide to split your LFE output signal, my advice is to simply check the signal voltage before and after. If it is the same, then you are perfectly fine and fire up that second sub!

Adding a second sub will give you a 5 or 6 dB increase in output. This will allow you to turn down the volume setting on each sub and keep the same SPL you had before with one sub.

This will give you lots more amp headroom and much less cone excursion and will add a more "effortless" quality to the bass.

Or, you could just deep six the whole second sub idea and buy a Velodyne HGS-18........

Spec