I am rebuilding some speakers from a modified/damaged Altec cabinets by a previous owner.
My idea is to reinstall boomer and tweeters in a new enclosure maintaining the dimensions of the original.
However, a few particular points concern me because I wouldn't want to change the "sound" of the speaker.
I would like to have your advice on assessing the degre of impact of modifications:
- Currently the original Altec enclosure is made of plywood for the back and sides and chipboard for the top and bottom. What would be the consequences of a single choice of materials?
- There are edges of around 2cm in which a protective strip was inserted like for formica furniture from the 60s. The removal of these edges does not affect the internal volume of the enclosure, but does it have consequences on the cabinet resonance?
- One of the diffractor cones on the tweeter is missing. Is it possible to reconstruct it using a 3D printer? What are the key points to watch out for?
thanks for help.
My idea is to reinstall boomer and tweeters in a new enclosure maintaining the dimensions of the original.
However, a few particular points concern me because I wouldn't want to change the "sound" of the speaker.
I would like to have your advice on assessing the degre of impact of modifications:
- Currently the original Altec enclosure is made of plywood for the back and sides and chipboard for the top and bottom. What would be the consequences of a single choice of materials?
- There are edges of around 2cm in which a protective strip was inserted like for formica furniture from the 60s. The removal of these edges does not affect the internal volume of the enclosure, but does it have consequences on the cabinet resonance?
- One of the diffractor cones on the tweeter is missing. Is it possible to reconstruct it using a 3D printer? What are the key points to watch out for?
thanks for help.
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Nice looking old speakers. Obviouslt used for small PA duty.
What tells you they are Altec? They don't resemble any Altec cabinet I have seen. Different style of construction. Those scream DIY.
Same with the horns, Do they have any markings on them? Or the drivers?
What tells you they are Altec? They don't resemble any Altec cabinet I have seen. Different style of construction. Those scream DIY.
Same with the horns, Do they have any markings on them? Or the drivers?
i highly doubt that the small changes to the cabinet your suggesting would impact the sound in an audible way.
the missing phase plug...now that's another story.
not that you would know but it looks as though there was swivel/turning bracket fitted to the top...perhaps they where hung somewhere but had the ability to be aimed ,maybe?
the missing phase plug...now that's another story.
not that you would know but it looks as though there was swivel/turning bracket fitted to the top...perhaps they where hung somewhere but had the ability to be aimed ,maybe?
Thanks for the pics.
The markings on the bottom corners were likely the original feet and the hole in the center looks to be where a pole mount receiver went.
As far as the phase plugs go, you could turn a couple of those on a wood lathe.
The 417's make a great MI mid bass and couple these units with a bass box and you have a decent very portable system.
Like turks says, you're not gaining a whole lot by going wild with the cabinet this is not for critical listening. Just make it look new again.
The markings on the bottom corners were likely the original feet and the hole in the center looks to be where a pole mount receiver went.
As far as the phase plugs go, you could turn a couple of those on a wood lathe.
The 417's make a great MI mid bass and couple these units with a bass box and you have a decent very portable system.
Like turks says, you're not gaining a whole lot by going wild with the cabinet this is not for critical listening. Just make it look new again.
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legs and a pole mount, that makes more sense i thought i was looking at the top...the opening is the port and not horn cutout...doh.
Hi fellows, happy New Year 🍾
The last owner made a hole for a pole mount and installed wheels. For my part, I prefer a rig with a clean fixing like in picture and no wheels !
I wonder why Altec chose two types of wood for its speaker. What are the benefits?
For the thingamabob at tweeter output, I wonder what it's for? To increase the angle of diffucsion of the treble? How do you reconstruct one?
That's the idea while avoiding doing worse! Not having any knowledge of acoustics, I prefer to ask for advice.
The last owner made a hole for a pole mount and installed wheels. For my part, I prefer a rig with a clean fixing like in picture and no wheels !
I wonder why Altec chose two types of wood for its speaker. What are the benefits?
For the thingamabob at tweeter output, I wonder what it's for? To increase the angle of diffucsion of the treble? How do you reconstruct one?
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You see more of it in the 80's for cost cutting. It is a cheaper material.
Gold standard was dropped in 71 and the gas crisis soon took over.
So by 75 when this line came out. Interest rates and fake inflation was already becoming a problem within only 4 years
For live sound equipment or Musical instrument by the 80's not only affordable lines but " expensive lines" also used it.
Particle board and MDF are horrible to use for portable speakers and easily damaged by moisture.
If your building a new cabinet just use all plywood.
3/4" or 18/19mm plywood and you can use bracing like more advanced designs.
Sky is the limit for a new build.
To restore the cabinet the plastic molding that is missing is called T molding.
Was becoming popular in the 70's as well in the arcade/ video game industry.
Widely available now since retro gaming and restorations are popular again.
The missing side handle is popular for Guitar amps and new replacements are available.
Often called " strap handles" or sold as brand name Fender or Peavey amp handle replacements
The pole mount is factory the 1975 Altec music gear catalog shows it pole mounted.
The holes in the middle where the castor wheels where placed are also factory.
Those would have hard rubber feet. There is a metal disc molded inside for strength.
Made by a company called Penn Elcom
Far as the missing phase plug. Maybe ebay and buy a full horn unit.
Or " replace" it by removing the other one.....LOL then they match.
Here's what happened to the speakers.
Until your answer, I had not considered an identical reproduction. I have 3 pairs and only one is in original state.
So as Cal said, I was just planned to make a box, painted in black (warnex) with some corners. Now I'm thinking about the best option !
This does not solve the problem of what you call the "phase plug". But it's a starting point to learn more about this technique and how it works..
Thanks.
Until your answer, I had not considered an identical reproduction. I have 3 pairs and only one is in original state.
So as Cal said, I was just planned to make a box, painted in black (warnex) with some corners. Now I'm thinking about the best option !
This does not solve the problem of what you call the "phase plug". But it's a starting point to learn more about this technique and how it works..
Thanks.
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seems like many a phase plug has gone bye bye either by accident or intentional removal...
the phase plugs...it's hard to say whether removing them or rebuilding/replacing them gives the better result sound wise...
you say you have one pair in original condition,correct?
if you like the sound of those then yes replace them.
these are old and the "phase plugs" where likely a kludge solution to a hot on axis response...calling them phase plugs is a bit of a lark because unlike a true phase plug which would be closer to the throat of the horn these are in the mouth.
la vie d'artiste pas de peinceaux est difficile!
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Yes but like so many similar things, I just gave up and joined the crowd. Yes they are likely nothing more than you mention, a deflector to deal with a hot spot.
speaking of crowds it's a good thing we're not lemmings....would it be lemming behavior to turn the discussion into one about "phase plug shapes vs far field results"...no wait then we'd be rabbits going down holes!
is Altec9440 building a new box? or just sprucing up the old one?
if he's build a new box i'd think about turning them into trapezoidal enclosures keeping box volume and port the same.
yea or nay?
if he's build a new box i'd think about turning them into trapezoidal enclosures keeping box volume and port the same.
yea or nay?
Hi,
I need to make at least 2 pairs of new cabinets. Old ones are too scrappy. I just think to keep last pair in original state with WhiteDragon's links.
I have not any stationary machine, but have some electric tools (drills, saws...). So I'm limited only with complex assembling (specific angle cuts....etc).
Turning them into trapezoidal enclosures, is interesting idea as It's a more contemporary form. But with my lack of knowledge, I can replicate a design but not compute my own 🙁
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no real complex computation necessary...some basic math for box volume...
what are the dimensions of the current box ? i'll gladly have a go at the math for and give you plan dimensions.
the first time i had a go at converting a box this way with the same familiar driver set i was amazed at how much better they sounded, the non parallel sides reduces box resonance significantly.
worth doing imho
what are the dimensions of the current box ? i'll gladly have a go at the math for and give you plan dimensions.
the first time i had a go at converting a box this way with the same familiar driver set i was amazed at how much better they sounded, the non parallel sides reduces box resonance significantly.
worth doing imho