Receiver is not sending any signal to the subwoofer

[jrrosas]

I am trying to tune my system, I am using the stereophile CD but no signal seems to be going to the subwoofer since it remains inactive. I have an Onkyo 705 and the subwoofer works fine if I play a movie.

My settings in the receiver are (gotten from Audyssey):
Fronts: Full Band (Polk RTi A5)
Center: Full Band (Polk CSi A4)
LFE: 80Hz

Do you have any recommendation on how to fix this?

Thanks!

[danger boy]

set your fronts to small, that way i'll send more of the bass to your subwoofer.

[djseafood]

Does the light on the subwoofer come on to indicate it is receiving signal? Not sure what kind of sub you have but many have an auto on/off circuit that automatically turns your subwoofer on when it senses a signal.

I'm not familiar with the "stereophile CD". Is this a cd with test tracks at different frequencies? Perhaps the track you are playing does not go below 80Hz?

[jrrosas]

I'll try that. Do you know by any chance the equivalent of "small" in Onkyo receivers?

[jrrosas]

And regarding the light on the back of the sub (Polk PSW202), it is in auto. I checked and it is red but as soon as I play a DVD or Blu-ray, then it turns to green.

The stereophile is a Test CD and I went through all the tests to be sure, especially the ones that are related to lower frequencies and it still didn't activate it.

[rdb2001]

And regarding the light on the back of the sub (Polk PSW202), it is in auto. I checked and it is red but as soon as I play a DVD or Blu-ray, then it turns to green.

The stereophile is a Test CD and I went through all the tests to be sure, especially the ones that are related to lower frequencies and it still didn't activate it.

Have you tried just a regular cd. I think it may be that cd. If it stays red during the cd, its not getting a signal for it to turn itself on. I would try another cd and also try that same test cd in someone elses system. IMO

[rdb2001]

And regarding the light on the back of the sub (Polk PSW202), it is in auto. I checked and it is red but as soon as I play a DVD or Blu-ray, then it turns to green.

The stereophile is a Test CD and I went through all the tests to be sure, especially the ones that are related to lower frequencies and it still didn't activate it.

Also have you did the audessy setup on the 705, did it recognize the sub when you did it?

[Face]

What mode are you using while listening to the test CD? Some modes disable the sub.

[kuntasensei]

If your mains are set to full range, nothing is sent to the subwoofer when playing CDs regardless of what listening mode you're in because there's no LFE track to be played and you aren't redirecting bass from the other channels. You need to manually set the crossovers on your 705 because Onkyo went against Audyssey's advice and used 80Hz as the threshold for "full range" instead of the 40Hz that Audyssey recommended. Damn near every speaker in Polk's product line outside of small satellites will surpass 80Hz on the low end, and thus will detect as full range in most rooms with Onkyo's implementation of Audyssey.

Your RTi A5s have a lower -3dB point of 40Hz, making them ideal for a 60Hz crossover (which will give it a half-octave transition across the crossover range and prevent gaps in the frequency response). I'm running older RTi70s on my 705, which aren't horribly different from the RTi A5s in response, so I think you'll like them at 60Hz. The CSi A4 hits -3dB at 65Hz, so you probably want to stick with an 80Hz crossover for that. You can try 70Hz if bassy voices aren't coming across with enough depth, but the lower you set the crossover point, remember that you're asking your receiver to provide more power to the speaker (since low frequencies take more power to produce). This shouldn't be an issue, however, if you're not trying to crank it to near-reference levels.

The LPF of LFE setting needs to be set to 120Hz and isn't adjusted by Audyssey's setup; it defaults to 80Hz to suit THX standards. If you don't have a subwoofer designed per THX spec, you don't need to use the 80Hz LFE low pass filter; the LFE channel is brickwall filtered at 120Hz by its very nature. The only way to accurately reproduce the LFE channel is to set this to 120Hz so the full track is passed to the subwoofer. Before anyone says it, you don't need to be concerned that this will make your subwoofer easy to localize, since mixers rarely place anything above 80Hz in the LFE track. There are, however, harmonics above 80Hz that lend the deep bass its tone, so get that low pass filter out of the way.

If you have any other questions about your 705, let me know. I wrote the Audyssey portion of the 705 FAQ over at AVS.

[Graboid]

I think Face is onto something. I have a Yamaha receiver and when you use the Pure mode nothing is sent to the subwoofer. I learned that by trial and error.

[jrrosas]

I set the speakers to 80hz and now the CD is sending signal to the subwoofer. I will now go and check kuntasensei's recommendations on the crossovers. I have an SPL Meter I was planning on using it with the Test CD but I got stuck with this problem.

Thanks everybody for the replies!