modified Altec Valencia crossover advice wanted

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Hello All,


My brother and I built some modified Altec Valencia speakers several years back. Woofers are 416-8a in a 10cuft vented enclosure (thanks GM). 806-8a's on 811-b's. The horns are mounted and coupled to the inside of the cabinet which quieted the ringing, and bloom, down quite a bit. We tried various dampening and we didn't find it helped nearly as much as coupling the horn, then minor dampening. Tweeter Fostex t90a. He also has my Horn Subwoofer hooked up, bought off of John Sheerin many years ago.

Crossover is stock Altec n800-8k. My brother is looking to possibly rebuild the crossover with new fresh parts. But he doesn't want to take that big Altec voice away.

I've read through hundreds of threads on Altec crossover redesign and I keep getting hung on the fact that I don't know the posters preference for music reproduction. When they say improvement I've really got to know what they like, and what they're after in sound improvement.

What he likes, and doesn't want to lose, is the big Altec live sound. When comparing my brothers system to my DIY EdgarHorn system I always thought of my stereo as being similar to a live concert sitting center room. You get the instruments, the musicians and you get the room in the presentation of the sound. On his, it's like that same live event, but sitting third row...right up front.

My abilities electronically are a could read a schematic, wire, solder, etc. I could build, just not design. We've tried changing out a few crossover points quickly in his system, putting a simple 1st order on the horns. It took all the like away. This is what I want to avoid...I don't want polite Altecs! I certainly don't want them honkey either.

I appreciate your time reading my post and look forward to any advice you have. I understand that this very topic has been done so many times before.

Any crossover recommendations are appreciated. As are component choices or crossover points that you believe will help us get to our goals


Thanks,
Dan
 

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GM

Member
Joined 2003
Greets!

Then just clean the pot [or better to replace with a fixed grid resistor assy.], any terminals and swap out the caps with good quality PIO [prefer 'motor run' caps myself] to get a bit more vintage [arguably 'more'] Altec.

Most folks migrate/recommend the M19's 1200 Hz XO, but this takes out the horn's PA/cinema 'bite' ['bark'?]/'presence', so strictly for HIFI buffs to my way of thinking.

GM
 
Hi Dan,

What's absent from your post is why either you or your brother feel there's a need to change the present status-quo.

Can you fill in those blanks please?

:)

Sure...good question


Starters, no doubt the pots are touchy. He recetly had an output stage on his amp go, taking the voice coil with it. Knowing the pots are bad, and the caps have certainly got some age on them we were looking at setting the crossovers straight. After repairing the 416's, and amp.

Thanks for asking, what are your thoughts.


Gm...yeah, that does sound like a good route to go.

Thanks,
Dan
 
Dan, you are certainly right to be cautious about "improving" the crossovers. Too many people who modify their old crossovers with modern film caps especially end up losing some of the magic of the original design. I find that modern parts can make a good first impression but you only notice the loss of musicality after using them for a while. Unfortunately most of the euphoric posts talking about how great the speakers sound with new caps are written before the new parts are even broken in.

I don't see anything wrong with experimenting with different crossover parts; just make sure you keep the old ones so you can put them back in if you end up disappointed. I would feel safe replacing old sand resistors with 12w Mills wirewound resistors of the same value. I would also feel safe about upgrading the binding posts and simplifying the wiring in the crossover. I did this with the crossover from an Altec 9849 and there were a number of jumper wires and unnecessary solder joints that I was able to eliminate through better wiring. Then I would consider swapping in a couple caps to see if you like the sound of them vs the originals. In the case of my 9849, the old Non-Polar electrolytics actually sounded pretty good; they were just a little edgy and not quite as detailed as some other caps I tried but still very musical and dynamic. After trying a couple caps, you could try replacing some of the iron as well. Again, the Altec chokes were pretty decent in the 9849 but they did add a slight edge.
 
I use modern Motor Run caps for my Altec 288-8K drivers ( on Emilar EH-500 radials ).

I like them a lot and certainly don't feel any need to change.
- FWIW, my motor-runs are made by Mallory.

Modern "Motor Runs" are typically not PIO, but are instead MPPIO ( metalized polypropylene swimming in a bath of cooling oil ).

Modern equates to this type being the norm for about the last 4 decades.

Surplus jobbers litter the eBay landscape hawking these types and usually sell at very reasonable prices.
- A lot of these caps are the domain of HVAC companies (FYI).

I would try out replacement 16ga-18ga air-core inductors ( in the HF leg of the network ) and any of the high quality ERSE 16ga laminated core inductors.

I would wait for a while to swap in new coils, first I would want to be really familiar with the sounds ( maybe differences ) caused by the new GPA recones.

New Caps & Coils are not a sure thing ( as most will say when dealing with Altec ) but instead something to be tried ( & rolled in & maybe right back out of a system ).

:)
 
Salectric, thanks for the sound advice. I really appreciate your viewpoint and will revisit the advice in this thread once we get the speaker back and everything else up and running. thanks!

EarlK, thanks, also, for the sound advice! I may have some extra motor start/run caps from putting my EdgarHorns together. If not, I'll look for some online, along with some similarly rated chokes when it comes time.

Thanks for the help all! I've got a good idea of the gameplan I plan on using when we tackle the crossover issues.
 
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