ultimate crossover - help

[TheoM]

I have been using an audio control richter scale crossover with my line arrays - which, among other features, have 24 BG neo 3 ribbon tweeters.

The Richter Scale is pretty good, but when I bypass it, dropping off the sub, the whole system sounds much better - except the Bass from the line arrays sounds a little mushy compared to my sealed sub. Ideally, I'd like the sub to handle 80 and below, and of course to be phase aligned with the top end. My options are, I think):
1) Use the crossover for the sub only, and hand match phase and xover point. This has the issue that I must split the signal somewhere and that could couse impedance issues. (fixable?).
2) Get a much more transparant crossover.

Any ideas out there for a much more transparant crossover? Has anyone experienced this? Is it reasonable to think I can get a large quality increment over the Audio Control - for any price? I've considered the Marchland - but I don't know if it will be better than the Audio Control.

Thanks in advance.

[LineSource]

Hi Theo,

I borrowed a Richter Scale from a dealer to try on my Apogee speakers and knew instantly that it destroyed the sound quality...veiled, poor transparency, dynamic compression, poor high frequency extension....just bad. Both the original 6db passive crossover and a 18db Krell active crossover instantly brought the magic back.

You could try replacing all of the opamps with the best reviewed here in DIYaudio that fit the PCB, and also replace any cheap capacitors in the signal path. These changes should bring it up to the same level as any opamp product like the Marchland

You could build a discrete opamp Xover like the MOX crossover in DIYaudio which clones a Nelson Pass JFET opamp.

The Richter Scale is your problem.

[TheoM]

I'll tale a look at the Krell. ted

[LineSource]

Theo,

After reading the Linkwitz info below on how DIY active filters can provide richer functionality than a Krell type which has just 3 diff amps per channel, you may decide to DIY to better match your speaker.

How to use active filters to compensate for many speaker imperfections
http://www.linkwitzlab.com/filters.htm

A rich DIYaudio discussion and discrete build...many pointers to good info
MOX - active crossover

TI's free active filter program
http://focus.ti.com/docs/toolsw/fold...filterpro.html

TI pdf chapter on active filters
http://focus.ti.com/lit/ml/sloa088/sloa088.pdf

[TheoM]

Linesource - I'm afraid I'm barely able to build passive networks - never mind the active stuff under question. I run a recording studio so my skills are... not in electrical engineering. Truth be told, I'm famously dangerous with solder. I use the Line arrays for tracking monitors. I used Bass box pro and a leap design etc. to design the LA's.

So I need something less challenging... but I can pay (don't want to but...)

I tried blocking the ports (making "leaky sealed") on the LA's and then integrating the Sub with a Parts express sub amp, and then aligning the phase with a db meter and tones generated at the -3db down point for the speakers - and that sounds better - but still, the sub sounds a bit ... disconnected from the high end. The curves don't match. If I had my druthers I'd notch out a room mode or two in the design process.

I agree about op amps - use the best or avoid them - but experimentation is ill advised for me at the moment as I have a lot of clients who depend on the sound. I love diy stuff - but I need to buy something in this case, I think.

[cixelsid]

A while back I bought a Richter Scale and returned it the sound quality was so bad.

Now I have a Marchand and a Behringer CX3400, and can't tell the difference between them. IMO both are very good