How do I bi-wire and bi-amp?


Power amps are QUAD 405 but with only one speaker output.

Suggestions gratefully received...
bigthistle
CHEAPEST great way is to buy Canare S11 starquad, and use two each of the 4 conductors for each set of connections on the back of the Quad 12 you have. THEN you can muck around with designer cables later if you wish.
If you want to bi-amp, you'll need an active cross-over and an additional amp. (stereo or a pair of mono's.) Subaruguru's response was for bi-wiring.

What speakers do you have?

Regards
Jim
Bi-wiring is just running separate speaker cables from the single terminal on your amp to the two sets of terminals present on bi-wire compatible speakers. Doesn't have to be special "bi-wire" cable--you can run two sets of normal speaker cables if you want and just stack up the spade connectors on the amp end. (There is usually a jumper plate connecting the two sets of terminals on the speakers that should be removed).

Bi-amping is running the separate terminals (generally representing the "high" drivers and the "low" drivers for the speaker) on the speaker off separate amplifiers.

In the former case, the "split" occurs after the amp and before the speaker. In the latter case, its a line level split after the preamp and before the amps. If you bi-amp, you can do it horizontally (one stereo amp for the low end, one stereo amp for the high end) or vertically (one stereo amp for the Left, one stereo amp for the right). Maybe I have that backwards, but you get the idea.

Jim, for the record, you don't necessarily *need* an active crossover to bi-amp--I'm bi-amping a pair of ML Prodigy speakers without an active crossover b/c, while MLs are set up for bi-amping, ML strongly counsels *against* active x-overs. For Bigthistle's info, there is a metaphysical debate as to whether I'm getting the full benefits of bi-amping. The debate (I'm simplifying) being balancing putting another active component in the signal path (passive bi-amping) versus allowing your amps to function better by having them only responsible for a smaller bandwidth of freqs. to deal with (active bi-amping).

I can attest, however, that I do get some benefits--I can hear them.

If you aren't using an active x-over, you need two sets of line level outs to feed the two sets of amps. Some pre-amps have two sets. For pre-amps that don't, you can get specialty line level Ys that create two. Or, you can get a funny solid metal block (for RCA connections) that turns one female RCA into two. That's what I've done.
Hi,

Could someone enlighten me a little on this subject? If one is using two amps which run independently to the high frequency drivers (ie. one amp to the highs) and one amp to the low frequency drivers, what happens to all the low frequency signal that is being fed to the high frequency drivers along with the high frequency signal? Maybe I haven't asked this correctly but someone may be able to get what it is I'm trying to ask. It seems that one bigger amplifier that is bi-wireable with speakers that are bi-wireable would be the favored approach.

I have an active crossover arrangement and know that the unwanted information for a driver is eliminated before amplification. This makes all kinds of sense to me and is a huge benefit that only the deaf could not hear. I can understand the benefits of more amplification and can see how another bunch of watts could wake things up. I can also understand doubling the ammount of speaker cable perhaps benefitting. What I'm having a hard time grasping is how more cables, power cords, etc. is better than a single, more powerful amplifier when dealing with conventional crossovers. Inquiring minds want to know.

Thanks,
Patrick
Patrick--the LF part of the signal going to the "High" input gets filtered out by the internal XO in the speaker. Same with the HF part of the signal going to the "Low" input of the speaker.

In my situation, the internal speaker XO can't be taken out of the path, nor does ML recommend use of an active XO, b/c the internal XO is really part of the ML Force Forward design. I gather there are some phase issues that go haywire with an active XO.

Perhaps I should have just bought "bigger" amps. But, I started with one that I had, and got a real good deal on the second one, so reality enters the picture (i.e., buy another VT100Mk III for $3K, or sell my one VT100MkIII for $3K and dump at least $6K beyond that on a pair of VTM200s). I can't bridge them to mono, and, even if I could have, I gather there may be bad issues with bridging resulting from halving the effective impedence seen by the amp, especially aggravated by complex low impedence loads like ESLs.

My rig sounds better now to my ears. Maybe that is because the loads presented to the two amps are easier to drive, even without bi-amping with an active XO. I have to believe the load presented by a high pass filter and an ESL panel is significantly easier for an amp to deal with than the load presented by a XO networked to an ESL and a conventional driver.