Bi-Amping

But I do not understand why the pre-amp needs to be cranked all the way up just to get nearly the same sound (dB) I had previously, using a single amplifier in bi-wire mode and yet the pre-amp would allow the amp to clip if I drove it to hard- (around +2 on the display) this would would be at ear spliting levels. Now, with the present set up, I can not clip the amps, even with the volume turn up as far as it will go. Mind you the B&K uses a digital volume control, and I have it set to it's maxium output of +8dB.

This is what I believe to be my problem. The specs for the B&K state 8volts max output, I wonder if this is indeed the problem?

Good grief.......

I missed this first time out.........

You have an 8" bass, 6.5" midbass, and a 3" dome midrange?

There is the clue why you don't like the sound. I won't even touch on the mish-mash of crossover points and slopes.

Go ahead......hate me.

After you get over hating me, seriously consider going active. I suspect that you will enjoy twidling with an active crossover. Much easier, and therefore more gratifying, than twiddling with caps and coils.

Cheaper in the long run, also.

I have built custom made crossovers, but they were all "twiddle-proof". It is too tempting to twiddle with them, and one can waste a lot of time twiddling and making things worse. Lots of fun, but not always a step in the right direction.

LOL, well I am not one to hate anyone, I appreciate your.....comments. However, you can, and may, snub your nose at my set up- but I would challenge you to a listen before you condem what I have built. With that aside, I enjoy the sound, as do every friend I have, some have better systems and say mine sounds better. But again, as previously stated, I believe the power output is limited due to the B&K's 8volt output. One listen to Rush's Red Barchetta, or Tchaikovsky's 1812 Overture, or Yanni Live at the Accropolis will instuct you as to the performance of a multi driver, extreamly low bass, done right system that can only be recreated using many drivers, not your typical 2 or 3 way system, but then the experts over at Wilson Audio have no clue why they use multi driver systems do they?

I have verified the problem - finally - I borrowed a Luxman pre from a friend that has a pre level sub out @75Hz- I believe, and I can now cause the amps to reach full power and clip, while the B&K sounds better, the Luxman gets much louder.

While I am no fan of bleeding ears, I am going to call B&K and see what can be done, if anything. Maybe I have a defective pre amp, who knows? (as of yet)

Again thanks for your comments.

8 volts should be enough to drive any amp or pair of amps into clipping. Take a look at the amp's sensitivity rating; it's usually around 2V for full output.

Kal

You can hate me.......it won't hurt my feelings! Some of my ex-coworkers will tell you that I made a career of getting people (mainly bosses) to hate me. Ah......the good ol' days.

Anyway.

Seriously, if you are going to try that many drivers, with that combo of crossovers, you MUST use some fancy measuring stuff to know that it is done right. In which case, you would know for certain what the problem is.

I'm not saying that multiple drivers, etc. won't work. I am saying that you can't guess what works and what doesn't. I think it is a safe guess that you do not presently have the gear to do such. Ergo, you don't know why you have a gain problem.

OK, back to your problem.

8 V out of a preamp is enough to melt any amp. Most amps have 26 dB of gain. A few dB either side, maybe.

As for drive, it should be able to drive 2 amps. Most amps are at least 10K input Z. That is not likely to be the problem. 5k is not that hard of a load to drive, which is probably a safe guess for worst case. A mismatch in gain more likely is.

As for your setup............you may want to try 4th order Linkwitz-Riley. That many drivers, with crossover points so close together, can be a nightmare. Not only do you have to take into account the phase of the crossover, but also that of the drivers. Heh, heh.....

One of my famous audio designer buddies had a very expensive multiple driver systen, made by a very well-known designer. I showed him how it had a nasty comb filter effect, depending on whether you were a short guy like me sitting down, or a really tall guy like him standing up. And everything in between.

He very quietly put them up for sale 2 weeks later.