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View Full Version : What Crossover should I use??



Gary L
06-13-2004, 06:26 PM
I am building a set of Altec Model 19 Clones.
I have 416-8A Woofers and 811B horns with 802-8G drivers.
I have been to Lansing heritage but can't find info about the Xovers.
Sure a set from 19s would be nice but none are listed in Ebay at this time.
I am not at all adverse to useing JBL but I just lack the info I need to buy the right crossovers.
Any suggestions with model numbers and xover frequency needs will be greatly appreciated.
Thanks for all the great info here in the forum.
Gary L

boputnam
06-13-2004, 06:29 PM
Here's what frequency the original used...

Altec Model 19, p2 (http://www.lansingheritage.org/images/altec/specs/home-systems/model-19/page2.jpg)

Gary L
06-13-2004, 06:50 PM
Thanks Bo, That page was the only one I could find with any Xover info.
It is all greek to me and I have to admit my limitations in this venture. I can build the cabinets and have had some great advice from Don and others but the electronics will be a constant sorce of info searching.
Even after I get the cabs built and speakers/horns mounted, I will be back here looking for the wireing sequence.
I saw some N8500s on ebay that were switchable between 500 and 800 Hz. There is a pair of heathkits now that are 800Hz and I have been told to search for a set of JBL 3110 or 3110As.
I just don't know what to do or what to look for at this point.
HELP!!!!!

Mr. Widget
06-13-2004, 11:45 PM
For the Model 19 the N1201-8A crossover is responsible in a huge way for it's sound quality. The 802 and 811 are equalized (tamed and response extended) through this network. If you substitute any other network you will not have the Model 19. It is a 1200Hz crossover with specialized built in equalizer circuit.

Here is a thread with a description of the Model 19 network:

http://www.audioheritage.org/vbulletin/showthread.php?s=&threadid=2554



Widget

Gary L
06-14-2004, 06:17 AM
Thanks Mr. Widget, I had just finished reading the post you directed me to when I made my thread.
I completely understood the ENGLISH but got lost with the diagram and all the electrospeak.
Evidently, I have to locate a pair of model 19 crossovers and they will be # N-1201-8A @ 1200Hz.
I have plenty of time to search and maybee someone here will chime in if they happen to have a set laying around.
I do want the specific sound of the 19 if at all possible.

Alex Lancaster
06-14-2004, 01:44 PM
Gary:

Sorry I recommended the 3110īs, I ASSumed they xovered at 800Hz, if the Altecs get difficult, JBL 3120īs are even cheaper, they do not have the bass boost, but You could equalize.

Alex.

Gary L
06-14-2004, 02:41 PM
Alex, You and I both made that same assumption and the more I get into this the more I learn.
I have not won any crossovers yet on either auction site so no problem.
I am just working on the box dimensions and useing some of your calculations to come up with inside and outside measurements.
I guess I am getting a bit lost because I am attempting to figure out the CU/FT of volume the 19s actually have and keep the volume as close as possible in my boxes.
The nearest I can tell, 19s had about 10.42 CU/FT minus what the components and bracing would take up.
Anyone out here who has some better measurements or calculations can certainly join in.
I need to make the boxes no more then 21 inches wide INSIDE.
The depth and height are negotiable and I am comming up with inside dimensions of 41" H X 21" W X 21" D. If I am figuring this right that should give me about 10.46 CU Ft.
If you are just getting into this, I am building boxes to fit the components of Altec Model 19s, 416-8A LF and 811B horns with 802-8G HF drivers. I am just trying to fit the new speakers to the wall space I have, no more then 24" each outside in width.
Height and depth are not set in stone and I need to keep the total volume of the boxes in keeping with what model 19s have.
I know alot of you would say NO WAY but I want to do this experiment and see what the end result will be.

Alex Lancaster
06-14-2004, 03:19 PM
Gary:

I donīt think the exact dimensions make a significant difference, as long as the volume remains the same; For Your volume, with a 1" baffle (speaker) board, either use a 5.125" round hole, no tube, or whatever shape gives You 21.65 sq in.

The very high compliance volume (Vas) of the 416-8B, and relatively low xmax, make for this huge box, if You were using a JBL 2235H, You would get a heck of a lot more bass with half the volume; But then, if You like them....

I would put the port near the bottom, to help with the bass.

If You need more help, that is what this forum is about; All of the above are my suggestions only.