Most that I'm aware of were MDF, I've only seen a factory 3/4" plywood 828 in a '74 MI catalog and a single pair for sale on ebay long ago with a very early build date code: http://www.lansingheritage.org/images/altec/catalogs/1975-mi/page12.jpg
All previous 800 series cabs were 5/8" plywood.
That said, by '75 I was winding down my DIY part time speaker design/building and all future Altec gear was just demos of new stuff at the distributor and now that I think about it, the later '78? 828 w/lower cosmetic grill I demo'd was made of some sort of Luan? panel [kitchen cabinet grade 'plywood'?] and worse, had no horn flare bracing!
Looks like yours have these grills, so curious how thick your panels are, etc..
GM
All previous 800 series cabs were 5/8" plywood.
That said, by '75 I was winding down my DIY part time speaker design/building and all future Altec gear was just demos of new stuff at the distributor and now that I think about it, the later '78? 828 w/lower cosmetic grill I demo'd was made of some sort of Luan? panel [kitchen cabinet grade 'plywood'?] and worse, had no horn flare bracing!
Looks like yours have these grills, so curious how thick your panels are, etc..
GM
Yeah, really sad; worst case I've seen was an 828 ages ago on ebay that had at least its side walls made with a blond wood grain vinyl covered particleboard like used on ultra cheap furniture, etc., with no bracing, corner blocking, etc..
At least it was covered on both sides, though the paint was so thin it was just barely visible and of course except for over spray was visible in all its ingloriousness on the inside.
At the time I made my cabs ['63-'64], I reluctantly did it strictly for cost reasons with mods recommended by master craftsman relatives, though after I got to experience some factory cabs up close and personal was really glad I'd been forced to.
GM
At least it was covered on both sides, though the paint was so thin it was just barely visible and of course except for over spray was visible in all its ingloriousness on the inside.
At the time I made my cabs ['63-'64], I reluctantly did it strictly for cost reasons with mods recommended by master craftsman relatives, though after I got to experience some factory cabs up close and personal was really glad I'd been forced to.
GM
@floyd carter - I fixed the post for you, but please don’t do it again, as it’s against the Forum Rules to post in all caps.
Aren't we all! I got a virus, banned plus a bunch of 'hate'/'obscene' emails for doing it on my first internet posting on an audio BB back in '96
. No slack at all........GM
Hi Marca,
I'm seeing your post a little late in the process, but wanted to commend you on the job you've done on your build. It holds special interest to me because I just finished my own Altec build a few months ago. In my case, I moved my 416-8Z woofers, 511 horns, and 802D drivers into 6.5 cu. ft. mahogany corner cabs of my own design. I also added a Beyma CP-21F slotted super tweeter to extend the UHF range.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I think you can eliminate the frequency response anomaly you've described by inserting the Altec 30923 CD equalization circuit between the hi frequency output and L-pad of your crossover network. This network worked perfectly for me, and was designed by Altec specifically for the problem you describe.
GeeDeeEmm
Living the dream
[special=]%[/special]Hi All,
Glad I found this thread! I am a longtime Altec enthusiast based in Sydney who was brainwashed as a child by an old family friend of ours who is no longer with us, Brad Sheargold. Now in my 30’s and with money to spend, I am beginning my dream Altec build.
I have part of my dads original Altec setup - yum cha Santana style cabinets with 420-8B’s, reconed by Brad about 20 years ago when one of the voice coils was smoked. At the time dad got a hold of some 902-16B HF drivers and Mantaray horns to pair with the 420/416’s along with a crossover design Brad had written on the back of an old brochure.
I have since got my hands on and restored a pair of 511b horns and matched with a nice Vincent SV237 amp.
Even with the small sealed enclosures, the sound is ... adictive.
I need to build some new wife friendly enclosures to make the most of the 416’s and have been reading the internet over the past month or so. My shortlist at the moment is probably the Stonehenge V due to its narrow and tall profile, but am looking for some guidance on my cost-is-no-object build. The MLTL enclosures look very interesting but may be a bit on the large side for my room. I would mount the 511b on top.
Great to meet everyone and I will be definitely putting this all in a build thread as things progress.
[special=]%[/special]Hi All,
Glad I found this thread! I am a longtime Altec enthusiast based in Sydney who was brainwashed as a child by an old family friend of ours who is no longer with us, Brad Sheargold. Now in my 30’s and with money to spend, I am beginning my dream Altec build.
I have part of my dads original Altec setup - yum cha Santana style cabinets with 420-8B’s, reconed by Brad about 20 years ago when one of the voice coils was smoked. At the time dad got a hold of some 902-16B HF drivers and Mantaray horns to pair with the 420/416’s along with a crossover design Brad had written on the back of an old brochure.
I have since got my hands on and restored a pair of 511b horns and matched with a nice Vincent SV237 amp.
Even with the small sealed enclosures, the sound is ... adictive.
I need to build some new wife friendly enclosures to make the most of the 416’s and have been reading the internet over the past month or so. My shortlist at the moment is probably the Stonehenge V due to its narrow and tall profile, but am looking for some guidance on my cost-is-no-object build. The MLTL enclosures look very interesting but may be a bit on the large side for my room. I would mount the 511b on top.
Great to meet everyone and I will be definitely putting this all in a build thread as things progress.
Attachments
Greets!
Welcome!
MLTLs don't have to be large per se, it's the driver's specs and owner's bass performance expectations that governs size. They do have to meet a 36" minimum internal height for its 1/4 WL TL pipe action to damp the vent, otherwise it's just a high aspect ratio reflex.
'We' already assume the cab will be at least as wide/deep as the horn and if you want physical VC alignment, then a bit deeper, so all that's left is height, which is normally based on the horn's centerline being at some [averaged] seated ear height or some folk's preference of placing the woofer at this location and angling the horn as desired.
If these are too tall, then what is max height to top of horn?
GM
Welcome!
MLTLs don't have to be large per se, it's the driver's specs and owner's bass performance expectations that governs size. They do have to meet a 36" minimum internal height for its 1/4 WL TL pipe action to damp the vent, otherwise it's just a high aspect ratio reflex.
'We' already assume the cab will be at least as wide/deep as the horn and if you want physical VC alignment, then a bit deeper, so all that's left is height, which is normally based on the horn's centerline being at some [averaged] seated ear height or some folk's preference of placing the woofer at this location and angling the horn as desired.
If these are too tall, then what is max height to top of horn?
GM
Hi GM,
It is truly an honour to meet a legend such as yourself!
The main issue I want to design around is width, provided I keep a smallish footprint, say the width of the 511b’s, they should be quite versatile in terms of placement.
I have read up on most of the builds of MLTL and other types of enclosures, but the main thing I want to try and leverage is the experience of people like yourself who have been designing and building awesome Altec speakers for such a long time!
When I have a bit of time, I will definitely start a build log with good plans so others can hopefully gain from this experience. I have found a really good cabinet maker over in Western Sydney who used to make up Altec pro audio cabinets in the 70’s and 80’s so I am in pretty good hands.
I quite like the look of the Stonehenge enclosures, so was thinking about interpreting the design and leveraging MLTL characteristics like speaker placement and a slot vent at the bottom of the enclosure.
In terms of dimensions and height, the main thing for me is width, a lot of the MLTL builds I have followed online are really wide. I would be fine with them about 23”, the same *** the horns. They can be quite deep and tall to make up volume. Nice deep bass response is high on the list of positive attributes.
Very keen to hear your thoughts and feedback.
I am fairly lucky that my father inherited a lot of old altec PA gear a few years back. We have been going through it all and have a number of good 816(ish) enclosures with 421-8h and LF drivers, quite a few 511b’s, a pair of 604 duplex speakers and old compression horns like 288c’s and 290’s. Lots of the kit is well worn and in need of restoration, but it means we have kit to make up quite a few sets of nice speakers, as well as having stand-by gear for parties so our nice high end stuff doesn’t get destroyed.
As well as the dream setup for me, I am also going to build up enclosures for the 604’s.
Anyway, thank you for accepting my above mind tsunami and I definitely look forward to speaking further!
Cheers,
Christian
It is truly an honour to meet a legend such as yourself!
The main issue I want to design around is width, provided I keep a smallish footprint, say the width of the 511b’s, they should be quite versatile in terms of placement.
I have read up on most of the builds of MLTL and other types of enclosures, but the main thing I want to try and leverage is the experience of people like yourself who have been designing and building awesome Altec speakers for such a long time!
When I have a bit of time, I will definitely start a build log with good plans so others can hopefully gain from this experience. I have found a really good cabinet maker over in Western Sydney who used to make up Altec pro audio cabinets in the 70’s and 80’s so I am in pretty good hands.
I quite like the look of the Stonehenge enclosures, so was thinking about interpreting the design and leveraging MLTL characteristics like speaker placement and a slot vent at the bottom of the enclosure.
In terms of dimensions and height, the main thing for me is width, a lot of the MLTL builds I have followed online are really wide. I would be fine with them about 23”, the same *** the horns. They can be quite deep and tall to make up volume. Nice deep bass response is high on the list of positive attributes.
Very keen to hear your thoughts and feedback.
I am fairly lucky that my father inherited a lot of old altec PA gear a few years back. We have been going through it all and have a number of good 816(ish) enclosures with 421-8h and LF drivers, quite a few 511b’s, a pair of 604 duplex speakers and old compression horns like 288c’s and 290’s. Lots of the kit is well worn and in need of restoration, but it means we have kit to make up quite a few sets of nice speakers, as well as having stand-by gear for parties so our nice high end stuff doesn’t get destroyed.
As well as the dream setup for me, I am also going to build up enclosures for the 604’s.
Anyway, thank you for accepting my above mind tsunami and I definitely look forward to speaking further!
Cheers,
Christian
Last edited: