[mgh0001]

i have 2 power amps and 2 4ohms speakers

each power amp in normal mode can handle 4ohms rated
each power amp in btl (bridged biamping) mode can handle 8ohms rated

if i was to put one 4ohm speaker with one power amp and the other 4ohm speaker with the secong power amp. could i have each power amp on btl mode, considering it is rated at 8ohms with four set of speaker wire to two speakers per amp.

Can Anyone Help?
cheers, mike

[Reiner]

Originally Posted by mgh0001

i have 2 power amps and 2 4ohms speakers

each power amp in normal mode can handle 4ohms rated
each power amp in btl (biamping) mode can handle 8ohms rated

Sure it's biamping mode and not bridged mode (which makes sense since you mention BTL *) )?

In biamping mode there is no change to the impedance the amp can handle, but in bridge mode the impedance that the amp can handle usually doubles.

if i was to put one 4ohm speaker with one power amp and the other 4ohm speaker with the secong power amp. could i have each power amp on btl mode, considering it is rated at 8ohms with four set of speaker wire to two speakers per amp.

You can biamp the speakers using four set of wires, but the amp must not be switched to briged (BTL) mode then. Obviously for biamping you need to split the L and R input signal so they can be fed to the two amplification stages of each power amp.

*) BTL = bridge-tied load

[mgh0001]

howdo, reiner. thanks for your reply. yes btl does mean bridged. i have corrected this typing error in my starting statement
cheers, mike

[Steve.EX]

Mike.

Without going into specifics, in the case of your amps (i say this as you have stated that they say: 8 ohms minimum bridged") their internal design is such that in bridged mode the amp (for want of a better term) "see's" only half of the speakers impedance.

So it "see's" an 8 ohm speaker as a 4 ohm load
It will see a 4 ohm speaker as a 2 ohm load, which is a mighty struggle for all but the crazy American(ish) poweramps. It is also presumed that this is a nominal figure and the speaker's impedance will actually drop lower!
There are a few amps that will run @ 1 ohm continuously, but they generally have power supplies and output devices that are akin to Battersea power station.
Your amp will just give up and die in a very short space of time.
As a footnote i am not at all convinced that bridging an amp offers anything in quality terms, infact i have always been of the opinion that it is in fact marginally worse.
I would bi-amp if i were you.

Steven

[Nic Rhodes]

I am not sure I know any quality advantages re bridging. I do know several for biamping. Bridging does give more power but as Steve has explained at quite a cost. Biamping doesn't have these limitations.

[mgh0001]

thanks for all your replies. of those intrested, i use 2 "sony ta-n9000es" power amps and a "sony ta-e9000" control amp.
cheers, mike