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Hello
I've just had a pair of Altec Stonehenge I and I find the sound poor, without bass and relief, I took off the loudspeakers and they are OK the screwdriver recognizes the magnet. I tried 414 without crossover and it runs better with more punch... I saw two small self in the crossover and I need the schematics to know how to let the 414 cuts HF alone (as 4312 JBL).
Best regards
Philippe
France
- The "screwdriver test" is pretty basic and doesn't really tell one much of anything . The magnet on that woofer is ferrite / not alnico .Quote:
Originally Posted by nazca
- The cabinet for the Stonehenge I is very attractive. If it was mine, I'd be inclined to throw away most of the original components / using the cabinet ( & maybe the 414 woofer ) for a DIY project with a compression driver/horn loaded midrange and top end.
- One could make a nice looking "vertical" Model 14 ( with a 931 horn & 902 compression driver up top / or some other replacements ) . A "reconditioned" JBL le14a would work very nicely in that size of enclosure for the woofer .
- Which model of 414 do you have ? The 8 ohm or 16 ohm version ?Quote:
Originally Posted by nazca
- There's definately a language problem here / I don't understand what you mean by "two small self" ( 2 small parts ? ) .Quote:
Originally Posted by nazca
- Anyways, I doubt if anyone has schematics for this obscure Altec speaker.
- You might be better off to remove a crossover and take some closeup pictures of the components so that someone can get an idea of just how simple or complicated it is .
- Installing a 414 will require you to come up with your own solution to cross into that big tweeter ( ie ; the schematics for the original network aren't going to help you very much )
<> :)
ps : So you know, I can't conitnue to reply to this thread / since I leave for a Xmas get away within a few hours .
- Some pictures of your Stonehenge One would be nice for all to see .
You can see the marketing specs here: http://www.lansingheritage.org/image...ome/page09.jpg from the 1976 Altec Home catalog - in French, too.
I remember selling these. We had a pair on the floor for quite some time before they found a home. Size was the issue - not the sonics - for its lack of sale. I'm quite pleased that a pair surfaced in Europe. I have had the perception that Altec did not have much of a retail consumer electronics presence there some 30+ years ago.
Crossover was at 1800hz to a phenolic ring tweeter on the Series I. These tweeters were quite common in many speakers of this era, BTW, mostly made by CTS, I believe. They may well need attention if the speakers were driven hard at some point in their life.
As to the problem at hand, I'd suggest a look to see if the woofers are wired correctly and that the crossover's wires are connected. This will have to be traced through the crossover. Seems to me those have been posted here before but I didn't take time to search.
I'd suspect the caps need swapping but that wouldn't address the woofer's lack of bass.....(a thought here) unless the woofer is getting the tweeter's signal?
These big boys can sound great. I can still remember the Altec demo record we used with them. One cut with Rita Coolidge's seductive voice on it still stands out as she seemed to be in the room with me on these guys.
If I had a set of Stonehenge cabinets, I'd use them for some projects:
- A set of the Stonehenge I or II models and replace the drivers with a 12" coaxial and bi-amp them with an active crossover. I always thought the form factor of the Stonehenge was excellent for a bigger speaker used in a residential environment. Would take some dinking around with the tuning ports though.
- A set of Stonehenge IIIs but add a sub/helper woofer on the back of the cabinet to be out of sight (pretty much like a UREI 813 but in a smaller cabinet), retune the port and bi-amp the 604 coaxial.
Apologies for pushing this post off-topic.....just doing a brain dump.
Cheers,
David
I think that he is trying to say that the XO might not be working properly.Quote:
Originally Posted by nazca
The caps values might have shifted more than 5% over 30 years.
Now were these firts or second order XO ???
It would be a cinch to build new ones .
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The 414 woofer, if in original condition, worked quite well in these boxes. We have to remember that they may have been reconed with less than appropriate aftermarket cones and therefore may not sound right.
The tweeter was actually made by ALTEC, it was a larger, bigger magnet version of a common Phenolic ring tweeter. It was built on a cast aluminum frame, early ones had an alnico magnet, later ones, a ferrite magnet. For what it was, it worked OK, as did the common phenolic ring tweeter, although this one was more efficient.
I would concur with the elvaluations of the above posters, the crossover probably needs new capacitors, the originals were simple 50 volt electrolytics, probably now wanting, although the inductors are likely fine.
The cabinets were exquisite, well worth the effort to upgrade them. Changing the tweeter to the horn/driver out of the Model 14 would be a great idea, but the crossover may or may not work. The model 14 crossover would not work either, it was very simple, the 414 has much better mid response. We here at Iconic have this on our to do list, just have not got there yet. Have fun with your Stonehenges, JIM