Altec 802D Crossover help

[cogito]

A while ago, I purchased a pair of Altec speakers. They are designed to have an external crossover.


Specs:


Woofer: 411-8A
Horn: 511B
Driver: 802D


All the components seem to be working fine. Spec sheet for the 802D driver calls for crossover at 500Hz with N-500E crossover network. Could not find the spec sheet for the N-500E, not I could find them on the web. However, there are a couple of N-500D crossover networks on sale on Ebay.


Anyone know the difference between N-500E and N-500D?

[Ed Kreamer]

Greetings form the Peoples Democratic Republic of Washington State

If your 802d is 8ohm you can use either the N501 or the N801 crossover. You don't state in your post that you have the attenuator EQ unit that altec made for that system. It really is a must if you want accurate reproduction as it tames the mid range and extends the HF in the drivers. I think the part number is 80904. If the 802 is 16 ohm you will probably have to build your own crossover. Altec's crossovers in those dark days were fairly straight forward 2nd order units if I remember correctly. ( a big If). Be sure you insert an L-pad for the 802 or it will run away from the 411..I think the 500e was a high power pro crossover. The d I don't know. Great Plains audio might have info on that. Oh one more thing, be sure to bolt the 511 to some wood to dampen the ringing.

Have fun, I hope this helps

Ed

[Earl K]

( Thanks Ed! ) .

Here's a similar thread for reference ! (http://www.audioheritage.org/vbulletin/showthread.php?37735-My-Winter-Project-Altec-Build)

Here's one way to go ( among others ).

http://images109.fotki.com/v779/photos/6/111916/12628482/AltecN5018a-vi.jpg

Here's the midrange suppression circuit ( that Ed is referencing ).

http://i653.photobucket.com/albums/uu255/Altec_Best/a4bd1a22.jpg

:)

PS; BTW. Art uses the same components, I think ( all 8 ohms ).

[cogito]

Greetings form the Peoples Democratic Republic of Washington State

If your 802d is 8ohm you can use either the N501 or the N801 crossover. You don't state in your post that you have the attenuator EQ unit that altec made for that system. It really is a must if you want accurate reproduction as it tames the mid range and extends the HF in the drivers. I think the part number is 80904. If the 802 is 16 ohm you will probably have to build your own crossover. Altec's crossovers in those dark days were fairly straight forward 2nd order units if I remember correctly. ( a big If). Be sure you insert an L-pad for the 802 or it will run away from the 411..I think the 500e was a high power pro crossover. The d I don't know. Great Plains audio might have info on that. Oh one more thing, be sure to bolt the 511 to some wood to dampen the ringing.

Have fun, I hope this helps

Ed

Thx Ed.

When I got them from an antique store, I was expecting the crossover inside the box. Read so much about Altec Horns, I am all confused now. To make the matters worse, I am on tour, so dont have access to the material from a few days ago.

Connected both the horn and bass sections without a crossover. Mid range was thin and little distorted and the HF were bright. Then read somewhere when used in A7 sealed box, the polarity of the Horn section needs to be reversed. They do sound lot better with the polarity reversed, HF brightness reduced significantly. Mid is still little thin. Remember reading somewhere that the HF needs to attenuated by 3dB. You mention Mids need to be tamed. This is what causing the confusion. Could it be because the box configuration?

I believe they are 8ohm drivers.

Couple of questions:
Any recommendations for the crossover frequency for 511B paired with 411? 500Hz or 800Hz?
N-500D and N-501 crossovers come with a HF attenuator built in. Do I still need a separate attenuator?

I will call Great Plains Audio.

[Ed Kreamer]

Thank you Earl

Cogito ( ergo sum?):

An antique store? Interesting and a good find. The 411 can be crossed over with good results at either 500 or 800 Hz. DO NOT RUN THE 802 WITHOUT A CROSSOVER!!! If you are going to be running the unit at VERY high levels use 800, for monitoring or Hi-Fi use 500Hz. This is what Altec did for their studio monitors or home speakers. 500 Hz I mean. I would definitely use the out board EQ unit especially if you are listening to classical music. Use the N501-8a that Earl referenced in his post.
They are readily available, and not too expensive.

It might interest you to know that in oh around 1974 I built a pair of monsters using 2 416's the 802/511 and n501-8's with the EQ gadget. (the 416's were 16 ohm wired for 8 ohms) They were glorious, but huge 11ft3. look up a photo of the Altec A-6 and you'll get an idea of it. I had a friend who later built the Altec 9848 using 2 411's ans the 288 Hf driver rather than the 416's. very similar sound but could go lower.

Have Fun

Ed

[cogito]

Ed,

You are right about the mid-range. I go these about 4+ years ago and they were sitting in the basement since then. When I powered them on last week, highs were harsh and mid-range was thin and distorted. Played a few hours since then, harshness in the highs is gone and the mids blossomed. Yes, mids need to be tamed quite a bit.

Ordered N-500-D crossover from ebay.
http://www.ebay.com/itm/Altec-N-500-D-Crossover-Networks-Pair-/252453173086?_trksid=p2047675.l2557&ssPageName=STRK%3AMEBIDX%3AIT&nma=true&si=lZxeiDgyTsSc6iYID3IYL9Hr%252B64%253D&orig_cvip=true&rt=nc

I will build the attenuator per the circuit Earl posted in this thread.

[cogito]

( Thanks Ed! ) .

Here's a similar thread for reference ! (http://www.audioheritage.org/vbulletin/showthread.php?37735-My-Winter-Project-Altec-Build)

Here's one way to go ( among others ).

http://images109.fotki.com/v779/photos/6/111916/12628482/AltecN5018a-vi.jpg

Here's the midrange suppression circuit ( that Ed is referencing ).

http://i653.photobucket.com/albums/uu255/Altec_Best/a4bd1a22.jpg

:)

PS; BTW. Art uses the same components, I think ( all 8 ohms ).

Thanks Earl for the circuit. It did make a significant difference for the better in the mid-range. Highly recommended.

[Earl K]

You're welcome! Glad to hear it's all working.

:)