Alte Cabinets: 612 vs 828

Dear Havenfolk.

I have finally gathered enough material for a first altec build: 806a and 32a horn, 416b drivers, jbl2405h tweeter.

I am trying to settle on a cabinet design and was thinking about the 612 cabinet. However, a 620 and even a 828 are not *that* much bigger. I wonder how the sonic differences between a 612 and an 828 based build could be described?

Maybe the more experienced members could drop some adjectives for me to get my mind rolling. Thanks! 🙏
How big is your room? t isn't just about the physical size of an enclosure it's way more important that it's a good fit for your space acoustically. In particular the 828 wants to breathe a bit, and even then it may not be well matched to a 32 horn.
I see the 32a is not necessarily the final horn. Thinking about an h808 by Trieu and the "let dauphin" by onken/hiraga.

My current room is too small for anything, buy that will change soon-ish, 20-30 qm2.
I agree with je2a3. I have Altec A7-MR994s, see my avatar, and when I considered building different cabs, most of what I found said the horn of the 828 was best matched to the 515-8Gs in there. I'm not a huge bass head and the A7s provided enough for my real world, non hip hop listening. My room is a basement 17' x 13' and I really enjoy the A7s down there about 13' away behind my desk.
I never used the 820 but have experience with the 416 in large reflex boxes (Model 19) and in 825 boxes. IME you'll get deeper and flatter bass from a 416 in a large reflex box--the 828 has a stepped response with the output from the horn loaded range of the 416 louder than the deeper reflex loaded range. On the other hand you might prefer the midrange of the horn loaded 416 in the 828 to direct radiating midrange of the driver in a reflex box. I found the 416 very pleasing either way.
I have a 12x13ft room with the Joseph Crowe mini onken box and it's sublime once I got a proper crossover in place.

I was afraid that I was stuffing too big of boxes and horns in my room, but its awesome and if I ever get a bigger room it will be awesome there too.

Running SET 5wpc.
Sounds like a great combination of drivers/horns, I think you‘re on what should be a fun and rewarding path. I’m currently using 416s in some modified 612 cabs and am quite happy with the combination. Bass is deep and clean and works well, IMO, with 500 - 1200 hz crossover points. I’ve settled on 500 hz, though some prefer a higher crossover point.

In my experience, 416s in 828 cabs have a little “cleaner“ midrange (midbass) but lose some low end compared to a bass reflex cabinet. Life’s all about compromises, right? Either way, I think you’ll enjoy whatever direction you choose. Looking forward to seeing how you project comes together.
Thank you for your response and encouragement and elaborating on the difference between the 828 and the 612.

Would you mind sharing how you have modified your 612 cabinet? I am thinking about integrating my jbl 2405h in the front baffle myself (uper corners).
Hello Blue_lu, these are the factory made pics of my 612 cabinets . I‘m using Altec 416 bass, the sound is very harmonic with the MK 808 wooden horn. The bass has not the power of the 828 VOTT cabinet because it had two Horns, a fronthorn and a backloaded horn, so it’s much louder than the 612.
Best regards Hififritze


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