View Full Version : Opinions, ideas, and suggestions for custom built cabinets for a pair of 601a Altecs

01-13-2011, 01:38 PM
Well after many years of searching, I have finally paired a 601a Duplex that I inherited from my late father. He had it paired with a 600b and since the horn on the Duplex was bad, the match was pretty close. He was no audiophile, in fact he didnt even realize what he had until I got old enough(and brave enough) to convince him to let me open the speaker boxes to see what was inside. Each cabinet had the woofer and a pair of paper 2" tweets, cabinets custom made by my uncle(I think was the story). I knew they were special drivers at the time(I was 13), just didnt know how special until I happened upon this site. They sounded pretty good, hooked up to an old Kenwood receiver (70's vintage), and he kept the system like that for more than 30 years. Sadly, one day a couple few years ago one of the speakers started buzzing(the surround on the 600b had let go)....by that time I had worked professionally in the speaker business in sales and service while going to college. I also did alot of custom car installs and home speaker projects(I guess it should be mentioned that I, like my father, and his father were all woodworkers by trade). I convinced him to shelf the speakers to prevent further damage while I searched for another 601a. After he passed away last year I decided to really start looking for a match for that Duplex feeling bad that I didnt get one while he was still around, finally found one relatively cheap a month or so ago. Catch was, it also had a bad horn.

From what I can tell not even Great Plains have the diaphragms for the horns in the 601a. This makes me very sad, but I have not given up hope. I have access to full woodworking and metalworking equipment, and if I have to buy diaphragms and modify them that is what I will do.....but that is a different story(and post). For the time being, I have several other horn options(from HLCD to 511s) to round out the sound....

On to the meat of my post(sorry for the long winded story....but I think it gives you all an idea of how committed I am to this project).

Here is what I would ideally like to do. Build a rectangular floor standing cabinet just wide enough for the driver on the front and place it at the top, slightly angled back to aim at the "seated to standing" listening position. I would also really like to have "windows" for the top section on both sides and the top, and a mirror on the back of the box. I know this is the worst thing I can do acoustically, but showing off the back of the speaker is important to me, as I feel these speakers really need to be seen. This is probably because it took me so long to get a look at the back of them when I was a kid...lol. The bottom of the box will be lined properly with fiberglass or something similar, and that is where I really need some design help.

First, I havent really been able to find many specs for the 601a, much less full T/S parameters. I assume they are designed to be "vented", I was planning of having the vent at the bottom of the speaker facing forward. I was thinking more of a slot than round ports.

Will my "windows" really make the speaker sound that bad? What would be the best material? Acrylic, or actual glass? These are going to be "forever" speakers and I dont want some plastic that will scratch or fade or turn yellow, so I was leaning toward actual glass.

Yes these speakers will be more of a conversation piece than my "reference" system, but I would still like them to sound decent. I will power them with a CJ EL34 based tube amp for now, but would really like to do some home brew SET amps designed specifically for these speakers somewhere down the road.

Any info, opinions, or ideas would be appreciated....thanks to all.....