Altec Big Red Monitors

[Claus K]

would anyone have more information on the Altec Big Red Monitors. I know they used 604 drivers and the Mastering Labs xover. I would like to know the size and whether they had an additional woofer.

Regards

Claus

[Guy L]

I own a pair.

The size of th cabinet s 30"x23"18.

The "Super red" version had an extra 15" woofer in a much bigger sealed box.

[Ar2]

And here are the speakers.

[Claus K]

Thanks Guy!

[Ar2]

If those posted images of measurement are not visible here they are as PDFs.

[toddalin]

You are running the Utahs too high.

The Mastering Labs put a big choke on it for a 1st order slope. The crossover even cost more because of the choke.



My Super Big Reds are triamped with passive eq units between the horns and their amp. This is in all probability a "one-off" created by The Mastering Labs.




These are the slopes:

HF (no passive eq added):


604 woofer:


Utah woofer (no bass boost engaged):


https://youtu.be/iGa9259pz-I

https://youtu.be/4MWmYYV1bg4

[Ar2]

You are running the Utahs too high.

The Mastering Labs put a big choke on it for a 1st order slope. The crossover even cost more because of the choke.



My Super Big Reds are triamped with passive eq units between the horns and their amp. This is in all probability a "one-off" created by The Mastering Labs.




These are the slopes:

HF (no passive eq added):


604 woofer:


Utah woofer (no bass boost engaged):


https://youtu.be/iGa9259pz-I

https://youtu.be/4MWmYYV1bg4

Thank you for your comments and details. I understand why it creates the wrong impression. I made the image when I just have finished construction. Measured curves are only for Altec. I actually run Utah's and Altec biamped through the software / hardware active digital crossover crossed pretty low - around 80 - 100 Hz. Altecs are run through the class A Nelson Pass's J2s and Utahs are driven with small 2A3 tube amps. I wanted to drive them reversed but they sound much better in the configuration I mentioned due to top end roll off on Altecs. You have a great set up !

[speakerdave]

Originally posted by Guy L
I own a pair.

I've wondered about that Mastering labs crossover. Is it sealed so that you cannot see the components and wiring?

David

[Claus K]

you can find the mastering labs crossover schematics on the soundpractices web pages under:

http://www.soundpractices.com/images/604xover.pdf

[speakerdave]

OK. Looks like one would have to make the inductor that is tapped at 10 percent.

Thanks,

David

[Claus K]

think that could be easily done by winding off a standard inductor til you get to the inductance of the lower part, apply a tap and rewind the wire.

BTW: I modeled this in SPICE and I´m pretty sure that the schematics is a bit misleading. I assume that the lower half of the tapped inductor has the lower inductance not as the picture may imply.
(which would be the other way round)

[Guy L]

Originally posted by speakerdave
I've wondered about that Mastering labs crossover. Is it sealed so that you cannot see the components and wiring?

David

The components and wiring can be seen. I'll have my camera back from service, within a week, and try to post pics.

[maxserg]

Hi Guy

so where is your camera

[hjames]

Hi Guy

so where is your camera

Well, Guy's last post has been here a while ...
01-29-2004, 05:16 PM

[Guy in WNY]

WOW! 6 years in the shop!