9846 Biamp upgrade

[arawak1969]

Well I found a pair of 1224 Biamps on epay last week and thought I would go ahead and remove the 771's and run seperate external amps and a crossover. This will give should greater flexibility and alow me to place the speakers futher away from the source.
I pulled the horns and drivers and repainted the boxes black. I also installed panel from 3/4" MDF to cover the holes left by the removal of the biamps.
Moldy has been really helpful and built me a few attenuators to replace the originals which had gone off over time. They sound great.

These speakers will be going to my sister un VA for her H/T mains. She presently has electrostats and was disappointed with them when she got them home. Sounded great in the store but never quite cut it at home.

[Earl K]

Nice

More and more I'm enjoying the look of those oversize horns dominating a single 15" woofer .

http://www.lansingheritage.org/images/altec/specs/pro-systems/9846-8a/page02.jpg

A couple of notes ;

(i) This model has aligned ( at the crossover point ) the two components' acoustic centers / as opposed to simply aligning the mechanical centers ( ie ; vertically aligning the voice coils )

(ii) I'm sure it sounds great .
- Do you feel the horn driver is replicating the curve I just showed ?

:)

[arawak1969]

My Dad had a pair of these when I was a kid and I grew up listening to them daily. I have had several speakers including L100's and ESS AMT-1d's and decided last year to build a pair. I found a pair of Santiago's before I could get the components together and just listened to them for awhile. I lucked in to this pair back in November and they had 806 drivers and 2225 woofers in the cabs with the n501-8A crossovers. It sounded okay beside the the 878's but it sounded muddy. The efficiency diff between the 806 with the Attenuators and the 2225 was off and I had no way to control them independently.
I pulled the woofers and put 411-8a's in along with 808/802 dia drivers and Moldy chipped in with new attenuators to replace the old ones and KABOOM.......... I was blown away. Things got even better when I dug out my Dad's 771 biamps and installed those. They have been a pain with one overheating and the other has a hum that I can't figure out.

I really think that these are well worth every penny.
I have heard several JBL speakers over the years as my Dad and his buddies had several go through their hands and I still keep coming back to these old units.
I really enjoy these old things.:cheers:

[arawak1969]

I have EQ'd for the roll off and it sounds pretty damned good since I added that.

[Earl K]

Thanks for the update ! It's much appreciated . :)

Hopefully one day I'll run into a pair of affordable, local, 511e(s) for my 288(s) ;)

[arawak1969]

Thanks for the update ! It's much appreciated . :)

Hopefully one day I'll run into a pair of affordable, local, 511e(s) for my 288(s) ;)
How far away is Hamilton from you?
I have family there and may be able to ge a pair of 511B's tp you if you are interested.

[Earl K]

Hi ,

That's a very generous offer but I'm looking for 511e horns ( with the 1.4" entrance ) to fit up to 288 drivers. Plus, I would be chopping them up so that I could copy them in wood / so / you don't want to get your horns involved in this sort of massacre . :p


How far away is Hamilton from you?

- Only about 50 miles .

:)

[moldyoldy]

Glad your new biamps worked out, Peter, and that you're back in high cotton. :)


...I'm looking for 511e horns ( with the 1.4" entrance ) to fit up to 288 drivers. Plus, I would be chopping them up so that I could copy them in wood ...

Geez, Earl, I thought I might be alone in the desire to chop up valuable stuff to see what makes it tick or to clone it! The last few "E"s I've seen brought $6-700/pr, expensive fodder for the grinder.

I've been wanting to do the same for a long time, only my resources suggest 'glass instead of wood clones. Been eying an unused "B" with a broken flange as a candidate, and expect I'll do it as soon as a few other things get cleared. Hafta extrapolate the length diff., but that appears to be fairly easy. Plans are to make a full length foam plug mold, then separate the halves to extract the mold and go from there. Will gladly share the results. Any suggestions/requests welcomed.

[spkrman57]

Earl,

They are a thicker cast aluminum horn with aquaplas coating and don't ring like the 511B/811B type.

I'm not sure if the 511E is of the same construction as the 811/511 type. I talked to Bill H. at Great Plains and he mentioned they took off about 1.5" of a 511B to mate the 1.4" throat.

I have 311-60 horns and they are 60 degree vice the 90 degree dispersion of the 311-90 horns.

Regards, Ron


Hi ,

That's a very generous offer but I'm looking for 511e horns ( with the 1.4" entrance ) to fit up to 288 drivers.

:)

[Earl K]

moldyoldy,

- I mispoke & therefore gave the wrong impression / if I had 511e horns I wouldn't be cutting em up / I would only butcher 511b horns .
- I want wood horns .

Ron,

- I could live with the size of the 511 but not the 311 .
- I have here, a 60° RCA radial. It's a fair duplicate of the 311 ( without the vanes ) .

:)