Biamping with 2 x identical amps, breakthrough

[Goldjazz]

Thanks I haven't done this before but I guess its easy enough to try. I don't know whether the horn sounds so much better now beacuse the caps in my passive network have drifted or if it just doesnt like caps in front of it as others have suggested. But perhaps a fresh cap with the added benefits of CC would preserve the clarity but protect
________
Peter[/QUOTE]

[loach71]

I don't use blocking caps (yeah I ride bareback) because they change the sound in my experience. IMO going active one speaker at a time is the way to go. The active speaker should be adjusted to sound as close to the original passive as possible, and then those settings cloned for the second speaker.

Shouldn't we call them prophylactic capacitors?

[audiomagnate]

Shouldn't we call them prophylactic capacitors?

Good one!

[SEAWOLF97]

Shouldn't we call them prophylactic capacitors?

do you bi-amp your F's & A's

[Ian Mackenzie]

If you search for 4343 upgrade I did a lot on crossover upgrades and the pros and cons of bi am ping.

Essentially the network was based on the 2121 , the 2420 old aluminium diaphragm and the 2405.

The drivers are fairly aggressive in that the 2121 has noticeable edge in its break up mode, the 2420 fades above 7000 and the 2405 is bought in hot to recover the detail.

There is some benefit in using more contemporary crossover capacitors however the best favour you can do is bypass the biamp switches this places contact resistance and prevailing insertion losses in the signal oath. There are post on what to do if you care to look around.

Beyond that the 2421 with the alumina diamond diaphragm is better.

The 4344 was the work of Greg Timbers and was a refinement in drivers and the network over the 4340 and 4343/b

As the active crossovers we found the Passlabs xvr1 was an audible improvement over the JBL and other pro units.

JBL did a great unit for the XP series but is NLA.

I understand Greg had used them and the Pass labs.

Pass now had have a great Firstwatt model B4 that is stunningly good, alternatively look for the Bryston unit.

The distinction is these are both discrete and operate in class A, this transforms the HiFi element into what the Japanese regard as a one of the best loudspeakers of all time.

In the Jazz bars in Tokyo the 4343 has a Cult status. I have seen Passlabs Aleph 2 pure class A power amps driving the 4343s in a bar there and the sound was really impressive.

I built my own diy Alephs and they seem to work well on the 4343 mid and highs.

The 4343 is a live hot sounding system and best served with smooth clean power amplifier

[Goldjazz]

Hi Ian thanks, yeah I've read your upgrade threads with interest. Lots of great information there I've learnt quite a bit reading it, and still learning so thanks for that contribution.

As discussed I've been playing around with quad amping (just one speaker) the past couple of days and its quite an interesting exercise as I start to understand the quirks of each driver. As discussed the biggest change was how much clearer the 2420 now sounds, so perhaps that biamp switch is partly to blame as well as you say. I do like the 2420 but it can be a harsh beast, it's just so clear and dominant and needs to be carefully blended in. I think the mosfets of my Perreaux 6000b are a little smoother on it than the harsher (but clearer) Sansui au10000 I also have. I bet a smooth quality class A amp would be the way to go as you say. I at least have a nice, smooth Class A Mark Levinson Ml-1 preamp ontop of everything.

Yes I was in Japan last year and visited many amazing Hifi stores all over the country, so witnessed their passion for the 4343 first hand. Didn't manage to see any 4343's in action in the jazz clubs this time, but will be sure to do that next time.

I am aware of the limitations of the behringer xover I'm currently using, I wasn't aware of the pass labs or firstwatt units you refer to so I'll look into those. I'm also quite interested in the Accuphase f-25. Will depend on if I continue down this quad amp approach or not.

Out of interest do you think there's merit in the quad amp approach or not?

If you search for 4343 upgrade I did a lot on crossover upgrades and the pros and cons of bi am ping.

Essentially the network was based on the 2121 , the 2420 old aluminium diaphragm and the 2405.

The drivers are fairly aggressive in that the 2121 has noticeable edge in its break up mode, the 2420 fades above 7000 and the 2405 is bought in hot to recover the detail.

There is some benefit in using more contemporary crossover capacitors however the best favour you can do is bypass the biamp switches this places contact resistance and prevailing insertion losses in the signal oath. There are post on what to do if you care to look around.

Beyond that the 2421 with the alumina diamond diaphragm is better.

The 4344 was the work of Greg Timbers and was a refinement in drivers and the network over the 4340 and 4343/b

As the active crossovers we found the Passlabs xvr1 was an audible improvement over the JBL and other pro units.

JBL did a great unit for the XP series but is NLA.

I understand Greg had used them and the Pass labs.

Pass now had have a great Firstwatt model B4 that is stunningly good, alternatively look for the Bryston unit.

The distinction is these are both discrete and operate in class A, this transforms the HiFi element into what the Japanese regard as a one of the best loudspeakers of all time.

In the Jazz bars in Tokyo the 4343 has a Cult status. I have seen Passlabs Aleph 2 pure class A power amps driving the 4343s in a bar there and the sound was really impressive.

I built my own diy Alephs and they seem to work well on the 4343 mid and highs.

The 4343 is a live hot sounding system and best served with smooth clean power amplifier

[Goldjazz]

Well, I've had a go a this and I'm pretty pleased with the result so far in terms of how it sounds, but lots more tweaking to do.

So I've got two Behringer CX3400 4-way crossovers, a Perreaux 6000b, a Perreaux 6000c, a BGW 750C, and A crown CE2000. The Crown is on the LF. Crossover at 300Hz to the BGW which takes the Midbass, then Crossover at 1250 to the 6000b, and then at 9KHz to the 6000C. Using a Musical fidelity M1 Dac, and Mark levinson ML-1 pre.

I also have a Rode NT-Usb condensor mic, and a the Room EQ QWizard software. I don't yet have a means of eq, but I'm aiming to get an anologue EQ such as a Klark Teknik DN360. All this gear is being run in a small room at the moment prob 15 feet x 15 feet . The room is partially open plan into a bigger space with effectively part of the wall behind the listener and ton the right side missing. Also One side "wall" is effectively a floor to ceiling glass sliding door, so not an ideal space.

Yeah so I assume the plots below are indicating a lot of peaks and troughs from reflections etc from the room. I've done as much with adjusting gain on the separate amps to get it as flat as possible. As I said no, eq applied yet nor any room treatments yet. Also all the amps are pretty rough, ex hire gear so I'll be going through each amp one by one recapping etc, starting with the second BGW I have.