2. amps-preamps
  3. 165566-22261

PASSIVE SUBWOOFER DRIVEN by a 2 CHANNEL PRE-AMP + MONOBLOCK ?

I’m hoping someone can advise me so a sub question
I have an 18 inch Passive subwoofer , the Wilson Benesch Torus

for some reason the engineers sell it with an external amp/crossover module . Inside is a 200 watt class Ab amp. To add insult to injury, I noted some made in China capacitors . A disgrace at this price point LOL

ive never been game to run it loud because I don’t think the amplifier has enough juice

if I experimented , say , using a stereo preamplifier and a 600 watt bryston monoblock and run my XLR cable from the subwoofer out on my home theatre processor —-> to my all analog stereo pre amplifier then only 1 channel on the preamp is being used . Of course the preamp then connect to my Bryston monoblock via an XLR plug



am I potentially doing damage to my preamp by only using one of its channels ?

200 watts seems a tall order to move an 18 inch cone at 20 hz at 80 decibels . I’ve spoken to several techs who feel most of the made in China subwoofer plate amplifiers are rubbish so I’m trying to avoid class D Chinese amps.

the Torus is a good  sub for 2 channel duties I remember reading it’s not that good for home theatre. Thank you if anyone has input.
wt4158

Showing 1 response by vanson1

vanson1
126 posts
 
I agree with your approach.  I had a plate amplifier die and then bypassed it and ran directly into the woofer from a amp connected to the sub out.

Worked fine. 

Keep experimenting until you are either out of ideas or out of money. 😁

I eventually built a 15 inch with dual passive radiators driven by a McIntosh amp in bridged mode. 

A non vented box gives a smoother frequency curve but not as strong a bass. A tradeoff. Certainly requires more power which is why almost all active subwoofers are vented. 

Vented boxes will have a peak resonance. This can be tuned by changing the length of the port insert tube. 

Experiment and have fun. 
More to discover