Biamp 603s1

[Hakka69]

I have a pair of 603s1 mains, I would like to experiment with passive biamping. I have Rotel RB-1070 and RMB-1075 amps.

The 603 series 1 have a passive bass driver, unlike the later models which are powered. They have a 3khz crossover, there are 2 pairs of speaker connectors on the back, one for the tweeter and one for the midrange. (I assume the series 3 have one set for the tweeter/mid and one for the bass.)

The way I understood biamping was to connect one amp to the tweeter/mid and the other to the bass driver.

Woud I see any gains from biamping? How would I go about balancing the levels between the tweeter and the midrange? Is it safe to connect a 130w amp to a tweeter?

Thanks.

Harry.

[Kal Rubinson]

1. I doubt it.
2. If the amps have identical gain figures, you are OK. If not, you will need to add an attenuator at the input to the more sensitive amp.
3. Actually, with passive bi-amping, you are connecting it to the tweeter and its crossover. That means that the crossover protects the tweeter from out-of-bandwidth signals and, as long as your balance is right (see #2), you are probably OK.

Kal

[Hakka69]

I have a Rotel RMB-1075 and RB-1070, I was planning to use 4 channels of the 1075, so my amps are identical, but wouldn't the driver sensitiviites be different betweent the tweeter and the mid/bass?

[Kal Rubinson]

I have a Rotel RMB-1075 and RB-1070, I was planning to use 4 channels of the 1075, so my amps are identical, but wouldn't the driver sensitiviites be different betweent the tweeter and the mid/bass?

No. If they are, you would have the same imbalance problems with a single amp.

Kal

[Hakka69]

Now that I think about it that makes sense, I might give it a try later today.
Thanks for the advice Kal.

Harry.