604-8H Crossover

Greetings,

It's been a while since I've been on the board, and I'm helping a friend make a pair of speakers using the Great Plains 604-8H II driver...I've tried the Yuki X-over, the Markwart X-over, and 5 or 6 variations of other crossovers, none of which rid the driver of the honk/beaming characteristics in the vocal ranges...

Have there been any advances in crossover design that smooth the 604-8H II out in that critical midrange area where the woofer crosses over to the horn? Through extensive testing and listening, it's the woofer that causing the beaming/honking, so is there a way to "notch" that out with a proper filter design? Has Has anyone been successful?

Thanks!

[QUOTE=Seadweller;1962030]Greetings,

It's been a while since I've been on the board, and I'm helping a friend make a pair of speakers using the Great Plains 604-8H II driver...I've tried the Yuki X-over, the Markwart X-over, and 5 or 6 variations of other crossovers, none of which rid the driver of the honk/beaming characteristics in the vocal ranges...

Have there been any advances in crossover design that smooth the 604-8H II out in that critical midrange area where the woofer crosses over to the horn? Through extensive testing and listening, it's the woofer that causing the beaming/honking, so is there a way to "notch" that out with a proper filter design? Has Has anyone been successful?

Seadweller scribbled..


"Through extensive testing and listening, it's the woofer that causing the beaming/honking, so is there a way to "notch" that out with a proper filter design? Has Has anyone been successful?"


Try hanging A beech towel top to bottom in the cabinet behind the 604 to help
damp internal reflections.......GC

What 604man says makes a lot more sense than might be initially obvious. Remember that Altec frequently specified in their building plans a rigid fiberglass panel running diagonally across the cabinet, top to bottom. The intention was exactly what 604man says - ridding the cab of standing waves.

And you are right about the woofer being the cause of the "beaming/honking," and relates directly to the fact that the high crossover point transfers midrange frequencies to the driver that is least ideal for reproducing them. Using one of the online crossover designers (for example: Parallel Notch Filter Designer / Calculator Help), you could easily design a parallel notch filter network as a starting point to attenuating the offending frequencies. That step alone will dramatically reduce the "honking," but will do little for the "beaming" other than making it less obvious.

Others with much, much more technical expertise than I will soon chime in with their own input.

GeeDeeEmm

A 10 ohm + 10uf Zobel on the woofer of my 605B 16 ohm Duplex helps minimize the honk. But that's a 416 derivative, possibly a Zobel tailored for a 515 might do?

JE