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View Full Version : Altec 807-8A HF driver and 811B Horn Question



Twinhit
03-27-2012, 06:54 AM
Hi,
New here,
I have a pair of Altec 811B horns, one with the 807-8A HF driver.

No cabs, no woofers... nothing beyond that.



What I'd like to be able to do is build a versatile test-bed cabinet system
using these horns and drivers.

Applications: Musical instrument amplification and HiFi stereo

I understand the driver was targeted toward musicians.
I think I read that the Symbiotik diaphragm is no longer avail but can be replaced
with an aluminum diaphragm.
I also understand that it is rated 30 watts RMS. I don't know if the aluminum diaphragm
reduces this rating or not.

This also leads me to be mindful of amplifier's watt output per channel. I certainly don't want
to cook the driver.

My question is how to go about making a crossover for this driver
I understand there is high pass filter, a low pass filter and bandpass filter, which I believe
are used in the 3-way crossover systems, while there is only a high and low pass for two-way systems.
I could be wrong.

I believe a basic passive crossover's components would include:

Capacitors
Inductors
Resistors
L-pads

Values unknown.

Anyway, I guess I am asking for directions to where I can find way to integrate this driver system
to a variety of amplifier power output ranges and... the crossover that protects the driver yet is well balanced
with whatever LF drivers that I may choose.

Is there such a thing as a filter that simply cuts frequency off at a certain point so this horn could be hooked
up to almost any LF speaker combination? ala a simple filter that prevents any audio below 800Hz from reaching
the driver, yet the LF side is not necessarily hooked up to a speaker as the horn is tapped off the main speaker?

Sorry I wish I knew what to ask. Still learning.
:confused:

louped garouv
03-27-2012, 10:35 AM
altec networks are generally pretty "textbook" like affairs from what i've read...

that being said, you can likely build clones with new components for
about as much as a vintage set of xovers would cost -- maybe less? :dont-know:

are you confortable with a soldering iron? how about reading schematics?

alternatively, if you have some spare amps and an electronic crossover sitting around,
you could use them --
and possibly have quite a bit more flexibility in your test bed scenario....

if using the 811 horn, I personally would try starting with somthing around a 1200 Hz XO point, like Altec did with the model 19 -- i'm personally not sure how the 807 and 802 response differs though....


WRT the diaphragms -- current offerings from GPA (great plains audio) include pascalite and AL -- the pascalite has the higher power rating...

good luck on your project!

rudy sesztak
03-27-2012, 12:03 PM
the 807 driver has a symbiotik voice coil diaphragm assembly. it handles more power, but the high end response is poor. there are newer voice coil assemblys with better highs,or you can add a super tweeter like a jbl 2405,or 077. the 811b horn sounds much better at a 1200 crossover.-RUDY

Twinhit
03-29-2012, 11:14 PM
Ok, thank you, guys.

Yes I know how to use a solder iron and understand blueprints, though I may need some help on some symbology at times.

Twinhit
04-03-2012, 12:35 AM
altec networks are generally pretty "textbook" like affairs from what i've read...

that being said, you can likely build clones with new components for
about as much as a vintage set of xovers would cost -- maybe less? :dont-know:

are you confortable with a soldering iron? how about reading schematics?

alternatively, if you have some spare amps and an electronic crossover sitting around,
you could use them --
and possibly have quite a bit more flexibility in your test bed scenario....

if using the 811 horn, I personally would try starting with somthing around a 1200 Hz XO point, like Altec did with the model 19 -- i'm personally not sure how the 807 and 802 response differs though....


WRT the diaphragms -- current offerings from GPA (great plains audio) include pascalite and AL -- the pascalite has the higher power rating...

good luck on your project!


What I have for amplifiers are as follows:

Two Stereo Amps:
a mid 60s Admiral tube console 2x12 (1 per channel) and 4 3"(?) speakers (2 per channel) Wattage unknown, presumed to be very low power via single ended design using 1 EL84 per channel.

2005 Sony STR-DE598 A/V Reciever 6.1 90W per channel
Two Guitar amps: 25W SS and 40W 6L6 tube

All amps are labeled as 8ohms.

Starting out:
What I would like to do is to be able to run these horns with different amplifiers and speaker combinations.

I'd like to be able to do is use Fender Blues Deluxe amp has a 50W Celestion Gold
12" speaker in it which is good for 70Hz-5000Hz.

Then use the Admiral


My thought was build something of an overgrown 2.1 "surround" system of sorts or....
a pair of two way or three way system with a separate subwoofer for the ultra lows..

I also have a Mackie 802-VLZ3 mixer that I would be using as well.

Can I do this with the equipment I have?

Future plans would be to use either an Altec 416-8A or 416-8B for the LF driver.

I am concerned about too much power or too little power.
And want to know how I can go about balancing the variety out.

louped garouv
04-09-2012, 03:33 PM
Starting out:
What I would like to do is to be able to run these horns with different amplifiers and speaker combinations.


can you elaborate, specifically?
maybe a diagram would help me see what you are typing...

:)
i'm dense sometimes, sorry