ALTEC A-7 cabinets built like ****!! - diyAudio
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Old 19th May 2007, 03:21 PM   #1
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Default ALTEC A-7 cabinets built like ****!!

Thought I might share my ongoing nightmare with you all.

Save any who might fall into this black pit of endless bottomless dispair from my fate!!

The short version: Altec A-7 cabinets are built so badly by modern standards that they are almost worthless, imho! Bringing them up to a reasonable level of solidity of construction is as much or more work than building from scratch! True.

It is amazing that they were able to be thrown about on the road as much as these "venerable old warhorses" are/were, without just shattering and falling apart.

Well, actually they did - based on the angle bracket repairs to one of the two cabinets that fell into my unlucky lap!

Cheesy plywood, low grade, nails, insufficient glue and tiny almost worthless glue blocks between cabinet walls. That's an A-7 stock.

The walls are too thin and unstiff - they have to be stiffened.
The cabinet leaks.
The speaker mounting throat does not fit flush to the "horn".
The horn is made of thin, kerf'd plywood, and is unstiff and undamped.
Everything rings, and is undamped.
The corners of "roaded" boxes are shot and beaten.
The bottoms are so bad they need to be replaced.
The outside is beaten into submission, no repairs to the finish is possible.
The strips that hold the back cover are riddled with holes and since they are nailed and lightly glued to second rated, now delaminating plywood, are almost not connected to the box.
The quality of the wood used where wood was used is laughable - one box even had wood stips with bark still on it!
And on and on and on...

More to come...

_-_-bear
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Old 19th May 2007, 04:26 PM   #2
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Howdy Bear, Did you ever consider that the whole A-7 sound people go nuts for is a direct result of there shoddy construction? Thin panels resonate adding acoustic energy to the room. It's not accurate but it may be part and parcel to that " dynamic vintage sound" people love so much. If you like that sound(not my cup of tea by the way) you might want to reproduce the cabinet using better quality construction yet keep the thin panels of the original. It's a dirty little secret that many of the classic speakers from the "golden age of audio" were slaped together like tree forts!
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Old 19th May 2007, 05:21 PM   #3
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Bear,

Is this the first pair you have become intimate with? Between the cabinets humming and the horns ringing you'd think they wouldn't sell at all, let alone for thousands of dollars.

They remind me of the old E series Jags. Some people love them. I'm happen to one of them. The day the empty cabinets arrived from Seattle I just about peed myself because as a lad I had grown up idolizing them. Just goes to show you the effect something "so bad" can have on you.

After all is said and done, there's just something magical about that box.
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Old 19th May 2007, 05:30 PM   #4
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Could have been worse. They could have used hot glue to put them together. The hot glue applications on most consumer speakers of that era would have had more secure bonds if the assemblers had used genuine authentic, hand picked snot.

Uhhh, that IS hot glue in these old speakers yes?

I have four authentic original Altec A-7 cabinets and they are under built for sure. At least mine came from theater installs and were not beaten up. Because these throw a good ways and sound best 25-30+ feet out front where the phase clearly comes into alignment one does not hear the cabinet issues. I never found them to be listenable in the near field, as in a average living room.
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Old 19th May 2007, 05:40 PM   #5
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Quote:
Originally posted by rcavictim
sound best 25-30+ feet out front where the phase clearly comes into alignment one does not hear the cabinet issues. I never found them to be listenable in the near field, as in a average living room.
Very well put.
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Old 19th May 2007, 07:34 PM   #6
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Quote:
Originally posted by rcavictim
Could have been worse. They could have used hot glue to put them together. The hot glue applications on most consumer speakers of that era would have had more secure bonds if the assemblers had used genuine authentic, hand picked snot.

Uhhh, that IS hot glue in these old speakers yes?


By "hot glue"', do you mean hot melt glue, or hide glue, which is melted in a heated pot for application?

Top notch musical instruments are still built with hide glue, and some believe that you can't get good tone from anything else. Maybe that was Altecs secret?
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Old 19th May 2007, 07:46 PM   #7
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Dear Lousy, I think rcavictim was referring to that glop that comes out of a glue gun. No way to treat a nice speaker!
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Old 19th May 2007, 08:18 PM   #8
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Hey Bear - I know what you mean!

Here is a pair I rebuilt about 20 years ago on Paris.
Click the image to open in full size.

These are still the reference system at the Magazine "Revue du Son."



This pair was in pretty good shape, I think they had come out of a cinema. The work consisted of:
  • Doubling up most of the walls. Done with 18 or 20mm Nantex marine plywood. The heaviest, densest, hardest wood I've ever seen! Extremely difficult to cut and drill. More like working with iron than wood. IIRC, the new panels were added on the inside, but I could be wrong.
  • Cross bracing added inside, of course. Same wood.
  • Tar added to the back of the kerfed horn. Some non-drying stuff that came in a can.
  • Corners reinforced inside.
  • Port size reduced.
  • Wool felt used for damping
The list above makes it sound easy, but is was not. A lot of hard work.

Results? Pure magic. Still my favorite speakers.
The bass is big, but has NO box sound. The only cabinets I've ever heard that don't. This goes a loooong way to making them sound like real music. And they do, they nail it. Plus they do all that 3D imaging stuff amazingly well - but that's the horns, I suppose.

The box design is a good one, a great one. But they were poorly made. As I understand it, many were built locally in the country they were sold in. Maybe some Altec guys can confirm that.

Older sound guys would look at me and chuckle when I told them my favorite speaker is an A7. But they never got to hear one like this.
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Old 19th May 2007, 11:24 PM   #9
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Lousy,

Yes. I was referring to hot melt LDPE that is dispensed from an electrically heated gun, usually onto stone cold surfaces which cool it solid before the surfaces can wet. The pieces are pressed together making a poorly bonded joint which has a lump of frozen LDPE in it preventing the pieces to be tightly fitted together.
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Old 20th May 2007, 06:08 AM   #10
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Quote:
Originally posted by rcavictim
Lousy,

Yes. I was referring to hot melt LDPE that is dispensed from an electrically heated gun, usually onto stone cold surfaces which cool it solid before the surfaces can wet. The pieces are pressed together making a poorly bonded joint which has a lump of frozen LDPE in it preventing the pieces to be tightly fitted together.

Ugh. Hot melt has its place, but that ain't it!
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