Am I wasting money on the theory of Bi-amping?

@asctim wrote:

With horn loading the problem is amp hiss gets highly amplified.

Indeed, but using a 16 ohm driver - if available - will help knock down hiss noticeably as well.

@btbluesky wrote:

Amp hiss, is not a normal thing. It’s a product of "too much gain in chain" + "not so good amp". I can crank up to over-concert level, and theres no distortion.

It doesn’t fall back on a "not normal thing" or a "not so good amp." High sensitivity, as has been stated just above, simply amplifies noise. If you removed the passive crossover from your JBL 4367’s and connected your amps directly to the compression drivers, I can assure you hiss would be audible to some degree - and yet your amps are the same; they didn’t suddenly get bad in the absence of passive crossovers (in fact they’d get better).

It’s great though you’ve found a good pairing amp-wise with the JBL’s.

@russbutton --

+1

Another major benefit is that you can use much, much lower powered amps when you use active crossovers. A lot of power is wasted having to push through a passive crossover. You really don’t need to push many watts into a tweeter or mid-range driver to get a lot of level out. You could even run a single ended tube amp on your tweeter, and a mid-level tube power amp on your mid-range driver, and a solid state amp for the bass driver. You have a lot of options.

Options are plentiful, yes. To me though the lesser power needed over the entire frequency range actively would be better served by spreading it out evenly, so to ideally use the same amps top to bottom, or certainly the same amp series/topology with a differentiated power approach for better coherency. To me coherency always comes first, and using similar amps is vital for this to come true in the best way.

If you removed the passive crossover from your JBL 4367’s and connected your amps directly to the compression drivers, I can assure you hiss would be audible to some degree

Nope. You are describing the scenario of what a normal system with an acceptable noise already present in the chain, but not when you are using absolute silent components. Lookup the AHB2 review from stereophile, the amp not only can adjust the sensitivity (9.8V RMS/22dBu, 4V RMS/14.2dBu, 2V RMS/8.2dBu), it has such a low distortion number, akin to the testing equipment that bench test the amp itself. If your upstream is absolutely silent, if theres noise/distortion in your horn, it's something else. Uber horn lovers pay big bucks for expensive tube amps, not just for it's tone/sound, more often it's for the silent. And they do directly connect to the compression driver with active setup.

I had my system horizontal biamped with mac275s on top and mc601s for bass. Tekton set me up with 4ohm biamp xovers. The whole house rumbles 

I would generally agree with a good number of the responses that indicate a "great deal of added expense to do it right" but yet the benefits are there if there is cost no object.

But here in "beerville", after experimenting with multiple different jumper wires between my mids and highs of Aerial 10 Mk II, I did find one that I liked substantially (Signature series, AntiCable).

Then at the suggestion of long time friend/audiophile Duane, I tried some Mosaic advanced tech speaker cables (now defunct) in a bi.wire mode .. UnBeLieVabLe the difference!

If you want similar tech .. Bionic Cables are similar yet better. I am using their entry level RCA, it is also amazing (coming from much a-b'ing on my system)

@barts - Please tell me that you also bi-wire in your tri-amp system.  I’ve often pondered what the limit might be for a complex audio system.  I would expect that the audiophiles with the most complex would also have the perspective that everything matters (why have a complex system otherwise?), so I can only imagine the challenge of optimizing cables and such, particularly every individual cable can be approached uniquely.