Installed new LSiW sub last night - broken 2nd time I used it

[bbeacham]

Yesterday my LSiW sub-woofer arrived and last night I replaced the PSW404 with it. After hooking it up I turned it on with the power switch set to "AUTO". I turned on my amp and as soon as audio started the sub's LED went from red to green and everything was fine.

Since I had other things to do I turned the amp off and returned a couple of hours later. At this point the sub's LED was red, which is what I expected since it is suppossed to turn off if no audio signal is detected. I then turned on the amp and DVD to continue watching (again) season 2 of the Sopranos.

At this point I thought that something didn't sound right and looked at the sub. The LED was still red. It din't detect audio and turn on. I reached behind the sub and flipped the switch to "ON" and the LED went green and everything was then fine.

I guess I can live with having to manually turn the sub on/off everytime, but it would have been nice if it worked longer than a few hours before it broke.

Of course what do you expect for $900? :)

On another note, although this is subjective I think that overall the audio sounds "better" with this sub. It is wired inline with my LSi15s.

[Dr. Spec]

If the auto on circuit is a little "sleepy", try boosting the sub level at the AVR or pre/pro and then recalibrate by lowering the sub level at the plate amp.

If it still doesn't work, take it back, or have Polk send you a new amp. I heard two others were bad at Tweeter stores, and couldn't be demo'd (see comments in another thread).

[bbeacham]

Since I posted this I have learned a bit more about this sub.

It appears that "Auto" does not quite work the way the manual describes how it should work. The manual says the sub will turn on after it detects a signal and turn off about 15 minutes after it no longer detects a signal.

First, the signal that the LSiW detects must be a low-freq signal. The sub will not turn on if, for example, only a conversation is playing.

Second, the sub turns off after what appears to be 2-3 minutes after the last low-freq signal went through the sub.

Personally, I would prefer it just turned on once any signal was present, rather than switching off/on/off/on/off/on during a DVD.

[Frank Z]

Try getting in touch with Ken at Polk Customer Service. He'll get ya fixed up.

[Dr. Spec]

Second, the sub turns off after what appears to be 2-3 minutes after the last low-freq signal went through the sub.

Personally, I would prefer it just turned on once any signal was present, rather than switching off/on/off/on/off/on during a DVD.

Again, if the auto on circuit is "sleepy", boost the sub level at the AVR or pre/pro and then recalibrate by lowering the sub level at the plate amp.

[bbeacham]

Dr. Spec prescribes:

"boost the sub level at the AVR or pre/pro and then recalibrate by lowering the sub level at the plate amp."

I cannot boost the sub-level at the amp. As I said in the original post "It is wired inline with my LSi15s." Polk does not recommend using the LFE to drive a sub and I have to agree.

Since this sub has pre-amp inputs I will be trying this method since my amp has pre-amp output connections. Maybe then it will come on and stay on.

[Kenneth Swauger]

Hello,
Both the line level signal and the speaker level signal are frequency dependant for the auto on/off function. This would mean there wouldn't be anything gained from switching to a pre-amp level signal. One thing to examine, however. Make sure the positive to positive and negative to negative polarity is maintained between the amplifier that is providing the signal and the corresponding connections on the sub-woofer.
Another consideration would be to use a filtered signal coming from the sub-out, of the pre-amp, to the LFE input on the sub-woofer, then activate the sub-out function in your pre-amp. In other words, you can provide both a speaker level signal and a filtered sub-out signal. The LFE input is not frequency dependant, it would allow the auto function to remain on irregardless of the signal's content.
Regards, Ken

[danger boy]

my SVS 20-39 is "sleepy" too. it takes a pretty good LFE signal to wake it up.. heavy sleeper. i'm sure it's fine.. but it just takes more umph to wake it up i guess.



I raise the LFE on my receiver till it wakes up.. then reset it again to the proper level. not a big problem. just would be nice if it woke up by itself instead.

[fireshoes]

I know you've read the manual, but I just want to make sure since you are using the speaker wire method, that the sub out on the receiver is set to off and the front speakers are set to no. If sub out were set to on, the receiver wouldn't be sending as much low frequency information through the speaker wire, therefor your sub might not turn on as easily.

Also as another option, just leave the sub on all the time. It's not going to hurt anything. I leave both my subs on all the time. Problem solved, no big deal.

[bbeacham]

fireshoes states: "Also as another option, just leave the sub on all the time. It's not going to hurt anything. I leave both my subs on all the time. Problem solved, no big deal."

Actually, I was wondering about that option. Just what is the differance between Auto/Standby and an amp that is "on" but has no input signal?

[bknauss]

More or less, you're using up more power. Its not much at all, but its something.