Subwoofer I get sound from my 5+1 speaker setup but no base frequency. I tried the subwoofer volume and frequency crossover jacks without success.

I would suggest your crossover unit has failed in the speaker cabinet. The crossover circuit board separates the low and high frequency content of your stereos audio signal. The low frequencies go to the bass unit (woofer) and the high frequencies go to the tweeter speaker. If the capacitor on the crossover goes open or near open circuit then noise is introduced into the sound system. Replace either the capacitor or crossover unit.

Hi,

How to Connect 2 Subwoofers to One Receiver

Subwoofers produce the deep bass sounds that give home theater the realism of being at the movies. A good subwoofer can rattle the walls during action sequences, while adding depth to recorded music and a heightened sense of feeling in the midst of a televised sporting event. Because most home theater receivers are equipped with a single subwoofer jack, connecting a second subwoofer requires a simple audio adapter available at electronics stores. Self-powered subwoofers have their own built-in amplifiers to drive the bass speakers, so they cannot drain power on the main receiver in a system and thus pose no danger to the equipment, even when an extra subwoofer is connected.

Things You'll Need:

Home theater receiver
Y-adapter with RCA jacks on two ends and an RCA plug on the other, available at electronics stores.
2 RCA subwoofer cables
2 subwoofers


Instructions


Plug the Y-adapter into the home theater receiver's "Subwoofer OUT" jack.


Connect an RCA subwoofer cable to each jack on the Y adapter and route the cables to the subwoofers in the room. Because subwoofers deliver an omnidirectional sound, the boxes can be placed anywhere they won't get in the way, but within reach of an electrical outlet..


Plug an RCA cable into the "Sub IN" jack on the back of each subwoofer.


Connect the subwoofers to wall outlets and turn on each unit by pressing the power button, typically located on the back panel.


Adjust the volume and crossover settings on each subwoofer as desired. The crossover adjustment knob tells the subwppfer which low-end frequencies to reproduce from the audio signal, such as a movie on DVD. All frequencies higher than the crossover setting will be transferred to the other speakers connected to the receiver.



Tips & Warnings

Use subwoofers that are closely matched in power, as rated in watts, when using two subwoofers in a home theater setup.

Disconnect the subwoofers from the power supply while making the audio connections.


Have a nice day...

There are several things you can do, but taking the simplest things first into consideration.

Wiring. If you have any loose speaker terminal connections at either end, or any stray strand wire near the receiver chassis it can cause this problem. It's likely that this is actually NOT the case in your particular situation as it appears to be volume control related, but this condition will also cause an overload message as well.

Speakers...lack of efficiency/sensitivity, high or otherwise unstable Ohm rating will require more power. Ohm ratings are based on a nominal impedance (resistance) of a specified input voltage by industry standards, and can vary considerably with signal frequency. Higher impedance occurs as input frequency is decreased...more on this later.

System setup. How many speakers are connected? Each terminal is designed for one channel connection. If you have multiple speakers, i.e.; spliced in series such as with separate enclosures that have multiple drivers, this increases the resistance and power consumption dramatically.

After the above considerations are addressed and resolved but you are still experiencing the problem, do one or all of the following;

Check your audio configuration. If your system has an equalizer, loudness control or "bass boost", turn them off. More bass requires more power from the amplifier, thus can be a cause of the overload you are experiencing.

Adjust your crossover. If you are using an active subwoofer, increase the crossover frequency point in the speaker setup menu of the receiver. You may or may not have to set your other speakers' setting to "small" to enable the digital crossover feature, but setting them to small is preferred in your case. This will allow the subwoofer (if an active one) to handle a broader spectrum of the bass frequencies, rather than the speakers that are being powered by the receivers' amplifier that is currently being overloaded. It will also improve the sound quality. You however, do not have to have connected nor use a subwoofer to do this type of setup, simply increasing the crossover point will omit some of the lower frequencies that are putting higher demand on the amplifier. Alternatively, you may also increase the crossover frequency at the source material, such as your CD or other player instead of in the receiver.

Home Theater

volume - personal taste - usually just high enough that you notice the bass - try turning down until you don't notice it then turn up one notch in the switch

phase - depends on distance from other speakers - try initially setting to 0 degrees

cross-over frequency - depends on your other speakers - try setting at 60-100Hz

I don't believe this hookup is amplified; but, if you have used the regular unfiltered speaker connections from your receiver/amplifier to hookup the subwoofer, the system will pass the signal thru the outputs subject to the crossover adjustment on the back panel. You cannot get the full signal if your system is sending only the bass signal to the subwoofer. I have copied the instructions below from the manual. You would set the high freq crossover to the low end of your satellite's frequency range. The full manual is here: http://www.jbl.com/EN-US/Products/Pages/ProductSupportDetails.aspx?PID=PSW-D110

High-Pass Control
• If you hooked up your subwoofer
as shown in Hookup
3 on page 4, you also have
the capability of adjusting
the high-pass frequency.
The High-Pass control
determines the frequency at
which the main speakers
will start reproducing
sounds. If your main speakers
can comfortably reproduce
some low-frequency
sounds, also set this control
to a lower frequency
setting, between 50Hz –
100Hz. This will concentrate
the subwoofer’s
efforts to the ultradeep
bass sounds, while your
main speakers continue to
reproduce the mid-bass
information. If you are
using smaller bookshelf
speakers that do not extend
to the lower bass frequencies,
set the high-pass crossover
control to a higher setting,
between 125Hz – 180Hz.
With this setting, your main
speakers will not have the
burden of reproducing any
low-frequency sounds.
• If you hooked up your subwoofer
as shown in Hookup
1 on page 3, the high-pass
frequency is fixed at 180Hz.
• If you hooked up your subwoofer
as shown in Hookup
2 on page 4, there is no
high-pass control. Unless
your receiver/amplifier
incorporates a high-pass
crossover, your main speakers
will continue to get a
full-range signal.
Final adjustment and blending
of the low-pass and high-pass
controls may evolve over several
listening sessions. A good
starting point would be to set
both the low- and high-pass
controls to the same frequency
and adjust from that point.

It could be the setup of the speakers, but I would install a crossover equalizer for your situations. A crossover equalizer is supposed to automatically filter the necessary frequencies to the correct speakers. I have used no name and brand name XverEQs and they both worked the same for me. Along with this response I am assuming you also have Mids and Highs to go along with the woofers.

There is a huge discussion among audio enthusiast regarding subwoofer output and how you should connect your sub to your system. If sub preout is turned and on your amp/receiver and you are able to adjust the crossover frequency adjust your crossover frequency to highest setting, higher HZ number, so you don't double low pass filter your signal too much. If you can adjust crossover frequency on your receiver and your sub allows separate connection to by pass it's filter, use that instead.
There is a great article on Polk Audio website regarding Home Theater setup. You can use it as reference and tweak it to your taste.

You set it to whatever sounds good to you.

It will power off if the frequency range of the signal being sent to it is set too low, or the amplitude of the signal is too low as well.

Try increasing the subwoofer crossover frequency and/or increase the gain from the LFE/SUB of the receiver/preamp you have it connected to. Also make sure that in the setup menus of ALL of your components have an LFE channel enabled such as by selecting the output of source material of your DVD player for example, to output 5.1. Otherwise, it will not send a signal for the subwoofer to play, nor will it play the signal if the crossover frequency is set too low.

Example; the setting on your DVD player setup menu is set to two channel: result with only one exception, subwoofer will not play

Example; subwoofer/LFE level on receiver/preamp set to -10dB and/or subwoofer volume too low. Result: subwoofer will not play.

Example; subwoofer crossover point set at 35Hz. Source material playing sound at 30Hz and lower. Result: subwoofer will not play.

i had the same problem when i tried to adjust speaker output levels, distance and equalizer manually without using audessy setup..so i reset everything to factory setting (0s)..and then ran 
audessy setup..reduce volume on your subwoofer to slightly above minimum(behind the subwoofer) before running the setup..once audessy setup is completed successfully..i started changing setup
manually..changed speaker config for front speaker to small (it is set as large by audessy setup), this should automatically adjust center and other speaker configuration (if not make sure to set them to small as well), then set the cross over frequency to 120..increase the volume on your subwoofer and now you should hear it fire..if this does not help..try playing some rock music with all channel streo mode..if your subwoofer does not fire even for this..then take the system back for exchange..