Can an active subwoofer be connected to a receiver designed for a passive subwoofer?

You can buy an adapter to convert from speaker output to RCA output, typically they are used in car audio where a head unit does not have low level outputs. It might work, and for the $10 for a converter could be worth a shot.Just go to Wal-Mart and pick up a 2 channel LOC. Will be in the car stereo section.

For the record, I have no idea if this would work in the home. But I don't see any reason why it would not work either.

My initial thought would be no because of the power requirements between an active and passive sub. The S3400 might not be able to detect a "modified" sub output as well.

The receiver sends power to the passive sub via the speaker wires (say 25V), your older receiver simply sent a much smaller signal via the RCA (say 1V) to the active sub, that was then amplified by the sub back up to 25V or whatever it happens to provide. When you add in the adapter, you are taking that higher voltage (25V) that the new receiver is sending (the receiver still thinks it is sending it to a passive sub), the adapter converts that back down to a low voltage (1V), which your active sub reads, and amplifies back up again to 25V as if it were still connected to your old receiver.

The only thing I can think of is that you might want to try to find out the RCA voltage of the old receiver, it may be very low, and if you then send your active sub 4v, instead of say 0.5v, you could run into potential issues. In car audio you would just turn the amp gain down, but I am not sure if your sub has a gain knob.

You can't just buy an "adapter" to fix this problem...lol.

The active subwoofer has a POWER AMPLIFIER built into the cabinet! Thus you just feed it a low-level audio signal and it amplifies it and drives the subwoofer's speaker.

The passive subwoofer requires an EXTERNAL POWER AMPLIFIER of about 150 watts RMS or more to drive it. You can't just feed an unamplified signal to it. You must connect a POWER AMPLIFIER between the receiver and the subwoofer to provide the power to drive the speaker. It does not have its own amplifier; that is why it is called "passive". The box contains nothing but the speaker.

Since an amplifier is likely to cost several hundred dollars, you would probably be better off getting a suitable powered subwoofer.

You could either use your old one or buy a new one.

The Polk PSW505 may be a much better powered subwoofer than what you have, and Amazon is selling it for under $200, which is a very good deal.





Edited by commsysman - 11/28/12 at 4:00pm

This is exactly what the adapter I am talking about does, it takes a high level audio signal, and converts it to a low level audio signal for use by an amplifier. Typically they are used in car audio when someone wants to add an external amplifier to a stock head unit that does not have any low level outputs.

Now, I am not sure if it would work successfully on a home theater application, but in theory I don't see why it would not. It takes the high level signal from his amp, converts it to a low level signal to provide to the active subwoofers amplifier. Ultimately though his new receiver will still be sending the high level signal to a sub, just via a converter to an amplifier, so it is still splitting its power to all the channels.

Your welcome, don't forget you can even try to sell your old sub in the classifieds to make some of the money back on the new system.