Altec Lansing 605A Duplex speakers in A20 Cabinet

[gdmoore28]

OP's cabinets are not an Altec product, and they ring like a drum head when he taps various panels suggesting that no soul with seasoned speaker construction experience was present for the build.

Those were never commercially installed in a theater. Likely the pet project of a serious audio enthusiast. 605 is not performing optimally in them. Minimally, the ringing panels need to be braced and damped.

The concept is fantastic, they're a very handsome corner cabinet faithful to the style of the period.

Altec didn't make an "820 cabinet"

820 refers to a system of components which the 821 cabinet was part of.

The "A20" tag is some kind of inventory control for a moving/storage company.

& & & & & & & & &


I'm waaaay late to the party on this post as I somehow managed to not see it.

Those are some very nice and classy looking cabinets, and I suspect (strongly) that, as usual, you've nailed the story in every respect. The only aspect that I might have a hesitation on is "that no soul with seasoned speaker construction experience was present for the build." Considering the cabinets that we have before us, I think that the builder did indeed have cabinet construction experience as testified to by the veneer orientation and generally robust material used. But the strongest indication that the builder knew what he was doing is best expressed in the oddball looking walls of the bass chamber - whatever the design was intended to be. Those panels took some head-scratchin' calculations and precise measurements and fitting to line up properly in that box. You are absolutely correct, though, that the by-then common concerns for cabinet rigidity seem to escaped some much-needed attention. Thank goodness, easily and cheaply done if the current owner finds them necessary.

Which brings me to my question to you, Bowtie. Do you have any idea what the builder used as a pattern for the port dimensions and panel orientation in these boxes? Seems that I've seen the arrangement used before, but I'm drawing a blank as to where. What name would have been used for that kind of arrangement?

GeeDeeEmm

 

[bowtie427ss]

Which brings me to my question to you, Bowtie. Do you have any idea what the builder used as a pattern for the port dimensions and panel orientation in these boxes? Seems that I've seen the arrangement used before, but I'm drawing a blank as to where. What name would have been used for that kind of arrangement?

It's an individual's flight of fancy based on A production cabinet, most likely a 606.

Were it built from published documentation, or any kind of established design, that information would have most likely been posted by now.

Seems that I've seen the arrangement used before

I think that amounts to the builder's inspiration, something he'd seen before.

Cosmetically, they are well executed, certainly somebody with serious cabinet making skills. But, i highly doubt they had anything to do with a speaker company. Visual appearance was obviously important. It's my WAG that the double ports were an exercise in symmetry, keeping them balanced, visually. Symmetry is often a component of beauty.

Acoustically, that it has 2 ports that large is the work of a pivot man, if you get where i'm going..

No data, lotta wank...

 

[bowtie427ss]

Most curious to me is the A20 tag. Seems like an inventory tag from an institution of sorts. The kind of place that would be under the control of a board of trustees.