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View Full Version : 421-8H & 511B/808-8A horns



JBLTEC
07-20-2006, 08:01 PM
Hi all,

It's been a while since I posted here. I'm trying to maximize my enjoyment of a recent purchase. I picked up a set of homemade A7's with the driver compliment in the thread title. They were primarily used as PA sound renforcement and bi-amped. Thus there is no crossover. I understand that the 511B/808-8A is capable down to 500Hz?????? Should I choose a crossover based on that or maybe go a bit higher? I am even more curious about the woofer. It's primary intent was as an instrument speaker. How is its reputation for hi-fi? Can it be reconed to be equivalent to something more suitable for hi-fi listening? Thanks for the help guys.

moldyoldy
07-20-2006, 08:34 PM
Hi all,
....... Should I choose a crossover based on that or maybe go a bit higher? I am even more curious about the woofer. It's primary intent was as an instrument speaker. How is its reputation for hi-fi? Can it be reconed to be equivalent to something more suitable for hi-fi listening? Thanks for the help guys.

The stock XO is a second order Butterworth with a pad, 500Hz, 12dB/oct. No need or room to go lower. The highest XO in them was 1200, mainly to protect HF drivers for livesound apps.

The 421-8H takes full advantage of the ~120Hz-800Hz horn, as it has peaked response there anyway (which is why it's not considered HiFi). The HO mid matches the larger 808 well with little padding. Just don't look for any extreme bass (it's the cab, not the 421), but a little added bracing and some port tuning will help. I'll get flamed for saying it, but I think if you added something else for the last musical octave (40-80), you'd be very impressed for HiFi.

Don't recone as anything else, there's lots of us that still love 'em in MI cabs.:band:

JBLTEC
07-21-2006, 06:32 AM
Thanks for the response. I had to use what I had laying around to give them a test run. A 2 way Radio Shack X-over @ 2K. I didn't dare run them without one. I pushed a good 30 to 40 watts through them with my H/K Citation amps and was fairly pleased. The goal is to use them with my tube setup. I want things to be right before I try it though. I thought maybe someone would tell me the horn does more for the sound than the actual driver. Just leave the woofer alone?????? Anybody here make crossovers to suit my application or recommend a specific one?

louped garouv
07-21-2006, 03:40 PM
if you want the stock altec 500Hz 8 Ohm ones, i have a pair that i am not using.... :D

JBLTEC
07-21-2006, 05:56 PM
if you want the stock altec 500Hz 8 Ohm ones, i have a pair that i am not using.... :D

Thanks for the offer. After much thought and a talk with a very helpful gentleman @ Great Plains Audio, I'm gonna go with at least an 800Hz crossover. I believe I've located a pair already.