2. amps-preamps
  3. 1051998323

Can I/Should I Bridge my power amp?

I use a 6 channel parasound amp (HCA-806) and my main speakers are Totem Rokks. I can bridge four channels to two, but the speakers' impedance are 4 ohms, and as I understand it, bridging channels effectively halves the impedance the amp is seeing, so that with 4 ohm speakers, I'd be asking my amp to drive a 2 ohm load. I'm a little worried about straining the amp and/or feeding too much power to the speakers. The Parasound is a high current amp with a plenty beefy transformer, but I don't want it to melt on me. Please help if you can with advice on whether I can safely bridge my amp.

Thanks.

D

The amp is rated as follows:

Continuous Power Output:
80 watts RMS x 6, 20 Hz - 20 kHz, 8 ohms, all channels driven
120 watts RMS x 6, 20 Hz - 20 kHz, 4 ohms, all channels driven
Continuous Power Output - Bridged
180 watts RMS, 20 Hz - 20 kHz, 8, each bridged channel, 3+4, 5+6
Current Capacity
30 amperes peak, per channel

The Speakers' specs:
� Impedance: 4 ohms
� Sensitivity: 88 dB/W/m. Maximum SPL 102 dB before dynamic compression.
� Minimum power: 20 watts at 4 ohms
� Maximum power: 80 watts
dkidknow
swampwalker's avatar
swampwalker
5,138 posts
 
Take this with a grain of salt, since I am not an electrical engineer, but I think you've got it wrong. If you run two speaker in parallel you half the impedence the amp is seeing. Bridging the amp doesn't change the speakers impedence.
sean
6,231 posts
 
When an amp is put into bridged mode, it effectively sees half of what the rated impedance of the speaker is. In this case, a nominal 4 ohm load would look like a 2 ohm load to the bridged amp. While the Parasound might drive such a load without major problems, my thoughts are that the tonal balance would be noticeably altered. You can give it a try and see how things work, but i would refrain from standing on the throttle until you were pretty sure that things were holding together and that the sonics would be something to your long-term liking. So long as you've got the proper fuses in the amp, all i can see happening is popping a fuse prior to things went into melt-down. Sean
>
dkidknow OP
60 posts
 
Thanks guys-- especially Sean. I was actually able to understand your response, which means you must understand what you're talking about. I willproceed accordingly.

D
More to discover