Axiom Home Page Forums General Discussion Technical Questions passive subwoofer connection

I have received various suggestions about how to connect a passive (no amp in box) sub in my home theater system. This is a quality sub, Phase Tech PC 90, and it would be nice to be able to use it. Does it need a separate amp? I have an old Crown 300A & Pre amp or can it be connected to my fronts using my Harman Kardon 700 receiver? Maybe the whole thing is a bad idea. Comments and help appreciated.

If you have an available separate amp, then by all means make use of it. Use an RCA-terminated coaxial cable to get the signal from your receiver to the amp, then use speaker wires to connect the sub to the amp.

Nothing wrong with passive subwoofers... actives came out out of convenience.

Chuck a mono amp on that sucker and let it go.

Bren R.

Garyo40,

As long as your H/K receiver has a dedicated line-level sub output, you should be able to use the Crown amp. Although you can regulate the level of the Sub output with your H/K, it's a good idea to use the preamp to give you separate control of overall volume of the subwoofer.

I'm assuming there is no passive crossover built into the Phase Tech sub. If there is, disable it or bypass it. You don't want to cascade two crossovers. You would only need to use one channel of the Crown amplifier for the sub because the dedicated LFE (subwoofer) output is a mono signal.
I have no idea whether Phase Tech subs are good, bad or mediocre. I don't recall that brand being distributed in Canada, and I've not heard one in the US.

Regards,

Alan,
Apreciate your thoughts. I need a more detailed explaination of the requred connections. Sorry for the ignorance. The PC 90 sub has rt & lft inputs & outputs & a high pass toggle switch 0db & -03db. The Crown 300A has reostat controlls fro Rt & Lft .
I connnected the rt & Lft to the Crown pre amp and an RCa from the Aux LFT to the sub out on my HK 7300 receiver. Power cord from 300A to pre amp inswitched and pre amp to HK switched. Connected the 300A to the sub Rt& Lft inputs. don't know what to do with the sub outs. hear nothing and feel nothing form the sub driver. What have I done wrong or not done? Plan to get the 500 Axiom sub but will do 2 pair of Axiom surrounds first so would like to use the PC 90 for a while. Thanks again for any help.
Gary