A Cautionary Tale- Particularly for BI-AMPER"S
Posted by: Geoff P on 24 January 2003
Whilst I am not currently bi-amping a brief test with two different types of amp just for fun brought an alarming discovery that would have otherwise gone unnoticed regarding the B&W CM4 speakers I use.
Since the amps were different makes I resorted to a test tone I had recorded to set the volume from each amp to the same level. To do this of course I had to drive each set of speaker terminals seperately at which point I discovered that one of the speakers was wired up the OPPOSITE WAY ROUND from the other! By this I mean the upper set of terminals on one speaker were connected to the tweeter and the lower set to the woofers. On the other speaker the upper set of terminals were connected to the woofers and the lower set to the tweeter.
If I innocently plugged in and biamped without tests each amp would have been driving alternate side high and low frequencies, which I guess would not produce the best result.
As for my own listening with a single amp, following the advised single connection to the tweeter terminals, with the terminal links in place as recommended by NAIM, and actually plugging the NACA5 into the CORRECT tweeter terminals on each speaker (which of course I had not been doing in all innocence up until then) produced a detectable improvement in delivery.
The moral is do not assume the manufacturer connected his speakers up correctly internally. Check in case you have the same situation you may have an instant audio upgrade available to you and you may feel like sending a strongly worded message to the speaker supplier aswell.
GEOFFP
Since the amps were different makes I resorted to a test tone I had recorded to set the volume from each amp to the same level. To do this of course I had to drive each set of speaker terminals seperately at which point I discovered that one of the speakers was wired up the OPPOSITE WAY ROUND from the other! By this I mean the upper set of terminals on one speaker were connected to the tweeter and the lower set to the woofers. On the other speaker the upper set of terminals were connected to the woofers and the lower set to the tweeter.
If I innocently plugged in and biamped without tests each amp would have been driving alternate side high and low frequencies, which I guess would not produce the best result.
As for my own listening with a single amp, following the advised single connection to the tweeter terminals, with the terminal links in place as recommended by NAIM, and actually plugging the NACA5 into the CORRECT tweeter terminals on each speaker (which of course I had not been doing in all innocence up until then) produced a detectable improvement in delivery.
The moral is do not assume the manufacturer connected his speakers up correctly internally. Check in case you have the same situation you may have an instant audio upgrade available to you and you may feel like sending a strongly worded message to the speaker supplier aswell.
GEOFFP