How do I bi-wire and bi-amp?

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.

Edesilva,

Thanks for the reply to my question. I hope I wasn't misunderstood as being critical, it's just that I couldn't (can't) grasp a benefit beyond a single, larger amp. I can certainly appreciate making the most out of a couple of excellent deals. :) The bi-amping as described seems to be a method of choice for a number of audiophiles. Many things that are discussed in the forums here are beyond my experiences with this being one of them. I have so many questions and life is too short to get all the answers. There are many ways to skin the audio cat.

Patrick

Edesilva- I'm not at all familiar with your ML's, but am curious about how you cross over before the signal gets to the amps. If passive, are you able to adjust slope and balance? How do you then run speaker wire separately to the LF and HF drivers? From what you seem to be saying, you somehow do a XO before the amps, then run speaker wires to the ML's XO, which sort of sounds like a hybrid bi-amp/bi-wire arrangement. Perhaps you could describe your set-up? I have a pair of Maggies that I'm looking to experiment with bi-amping and would like to consider all options.

Patrick- One of the other advantages of bi-amping is that you can use amps with less power as both amps work more efficiently within their narrower bandwidth. Typically, the amp for HF is around half of the power of the LF amp as LF's suck alot of power. A 200 watt LF amp with a 100 watt HF amp plus the XO may outperform and play louder than one 300 watt amp.

Regards
Jim