Crossover - Altec Lansing Valencia 846A / Altec 511B Horns / GPA 902-8A drivers

CopperFoil

  • Jr. Member
  • Posts: 10
Hi,

I recently acquired a pair of Altec Lansing Valencia 846A speakers.  I have next to zero experience with horns, know very little about any of this vintage stuff.  I got the speakers to "play with horns", and also a much higher sensitivity setup.

The woofers are the original Altec 416-8A, but the horns have been replaced with Altec 511B horns mounted on top of the cabinets. 

The drivers in the horns are GPA 902-8A drivers. 

Supposedly they have "Zilch 19 design" crossovers, and that is something I would like to play with a bit. 

Wondering if anyone has a simple schematic for pairing this particular Great Plains Audio driver with this woofer, or similar setups. 

I'd like to try simplifying the crossover setup, remove the hi / mid potentiometers, etc.  I tried reaching out to Great Plains Audio for a basic network that would work with this horn, as I assume this is a fairly common thing?  Left a message for them but no call back. 

May try them again, but thought there may be some other examples of simple, known networks that are a good place to start.

So, I'm checking here.  Thanks for any help / advice.








FullRangeMan

  • Volunteer
  • Posts: 21757
  • Audio Transformers Consulting
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Remove volume pots will be an upgrade.
Alnico 5 always delivery great harmonics.
I would suggest copper ribbon air core inductors as Goertz etc
This horn are fiberglass ?

rooze

There was an article on the GPA website that was published by the previous ownership, but it has been removed. It's still accessible via WayBack web archive here, and it's well worth a read: https://web.archive.org/web/20200804025317/https://greatplainsaudio.com/gpa-vintage-altec-ezine/altec-lansing-valencia-improving-classic/

Basically, they recommend ditching the passive XO and going active. They used a Behringer unit and changed the XO point shifting it to the Model 19, changing the 800hz XO point to 1200hz. I did some work on this when I had Valencias and published it on my blog at https://www.audioresurgence.com/2022/03/altec-lansing-valencia-846b-restoration-project-and-review.html of course all this pertains to the 811b, but the active path is probably still the best way forward.

You can do it quite inexpensively if you've a pair of stereo power amps at your disposal. You can use a miniDSP 2x4HD which can be found for a couple hundred used, along with the UMIK-1 mic.

Otherwise if you prefer to stay passive, I can't really offer much other than 'good luck' with this fantastic speaker.


CopperFoil

  • Jr. Member
  • Posts: 10
Remove volume pots will be an upgrade.
Alnico 5 always delivery great harmonics.
I would suggest copper ribbon air core inductors as Goertz etc
This horn are fiberglass ?

Hi, the horns are cast aluminum:

https://vintagetechnologyarchive.com/audio/altec/511b-horn/


CopperFoil

  • Jr. Member
  • Posts: 10
There was an article on the GPA website that was published by the previous ownership, but it has been removed. It's still accessible via WayBack web archive here, and it's well worth a read: https://web.archive.org/web/20200804025317/https://greatplainsaudio.com/gpa-vintage-altec-ezine/altec-lansing-valencia-improving-classic/

Basically, they recommend ditching the passive XO and going active. They used a Behringer unit and changed the XO point shifting it to the Model 19, changing the 800hz XO point to 1200hz. I did some work on this when I had Valencias and published it on my blog at https://www.audioresurgence.com/2022/03/altec-lansing-valencia-846b-restoration-project-and-review.html of course all this pertains to the 811b, but the active path is probably still the best way forward.

You can do it quite inexpensively if you've a pair of stereo power amps at your disposal. You can use a miniDSP 2x4HD which can be found for a couple hundred used, along with the UMIK-1 mic.

Otherwise if you prefer to stay passive, I can't really offer much other than 'good luck' with this fantastic speaker.

Thank you!

FullRangeMan

  • Volunteer
  • Posts: 21757
  • Audio Transformers Consulting
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
Hi, the horns are cast aluminum:

https://vintagetechnologyarchive.com/audio/altec/511b-horn/
When they are working please inform us if it will have the duck voice or not.

aldcoll

  • Full Member
  • Posts: 775
  • Champagne Taste on a Water Budget
I have a friend that has tooo many to count Altec horn and woofer cabinet options to listen to. 

The Volume know is for matching/adjusting Ohms and db differences for personal choice.   Your drives appear to be Ohm matching per their part #.   It's a lot of personal preference for listening.

I do know that Great Plains is small staffed and Very Busy and a small staff.

The one thing I liked about listening to the Older Altec or even Electro Voice as I have is using a Bi Amp set up to customize the sound.

I have had to SUFFER many a hour in my friends basement over the last year or so and I have lost count of the amp speaker combinations/configurations but for me a 2A3 amp upper was my favorite.

And I will throw out the Current 416 and 604 in a Open baffle setup is a show stopper.

But what ever its a personal choice and what your ear likes.  And for what it's worth his Wife said She stays if the current Open Baffle stays.  And She is a Keeper.

Enjoy the journey.

Alan

S Clark

  • Full Member
  • Posts: 7586
  • a riot is the language of the unheard- Dr. King
A few years back I took my Altec Flamenco (nearly the same as the Valencia A) to Danny Richie for crossover work.  We also converted to open baffle, moved the crossover point down a bit, and tamed a frequency hump with a notch filter.   

FullRangeMan

  • Volunteer
  • Posts: 21757
  • Audio Transformers Consulting
    • Never go to a psychiatrist, adopt a straycat or dog. On the street they live only two years average.
On the PDF specs the Altec 416-8A can be cut til 1600Hz.

CopperFoil

  • Jr. Member
  • Posts: 10
Thanks all. 

The speakers work... I bought them from a guy who was EQ'ing them quite a bit and I knew they would be a bit of a project... but I wanted to try a horn speaker and these seemed to have special GPA drivers, so I figured why not. 

They have hints of being able to be very special, but I think the network could use a bit of work, and I am picky about what I like.  I am sure some would like them just as they are. 

My wife is not super excited about the look, and others may like them exactly because they look the way they do.  I may end up moving them along to another enthusiast if I can't come up with something fairly painless. 

S. Clark, I did see where you mentioned going to see Danny with your speaker.  I'll reach out to him about the network he did to yours - see whether he has a basic network I can throw at them to see how they respond.  Shipping one to Danny is out of the question... but I am sure he could get them "right".   

I have a big pile of caps and inductors around here.  We'll see how it goes.

Thanks all for the input - and for any additional input as well.   8)