Altec A7 825 cabinets v 828 cabinets

[Robert N. Dunn]

Hi everyone, it,s great to have discoverd this resource!I got the Altec bug from a friend who talked me into building a pair of 211's.I was totally unprepared for the quality,[and quanity!!],of sound.I am now planing to build some A7's,and would like opions about any acoustic differences between 828 cab's and 825 cab's.I have plans for the 828's but cant find plans for the 825's.Thanks'Bob one

[RacerXtreme]

How did the 211's come out?

What freq. are you x-ing them over at?

Guy

[Robert N. Dunn]

Hi Guy,The 211's, when we fired them up, were a revelation! I hadnt been around any VOTT stuff and I had no clue what to expect.We crossed 421-A's at 750Hz with a elec.xover to a 603-b lens & 288-K16 drivers, they sounded great.I say sounded because they were lost in a fire.We will build some more large format horn enclousers but I'm still reseraching smaller or modified cabinets,any input? Thank's

[Altec19]

The 828's were an improvement over the 825's because of increased internal bracing, thicker plywood, and finally a change from plywood to MDF board. I think they were identical in dimension and since both cabinets had a little too much internal volume to begin with the additional bracing helped decrease that volume. I've had these two cabs side-by-side in my garage and I don't recall there being any difference in size. If you are going to build some, go 828 and add yet some more bracing. I think there may have been discussions about that in an earlier thread.

[RacerXtreme]

Hi Robert (Bob ???), I don't have any experience with the 211's but I've owned four A4's (210's) for about 20 or 25 years now. As Jim Dickenson said in his article - "there is no such thing as too much internal bracing". Did you ever try Titanium diaphragms in the 288's ? I was getting them fairly cheap from Image Communications near Chicago, and in my opinion they sounded a little "crisper" than the original aluminum diaphragms. And they were WAY cheaper.

I'm trying to stuff some JBL 2225's in my A4's 'cause the 515's just kind of run out of gas when you push them hard. Time to experiment....


Guy

[Robert N. Dunn]

Hello Guy, In my experince with the 211 speakers I noticed that they sounded muddy standing close to them but at 30-40 feet away they were very articulate and with apprx. 40 watts of input we were rocking our local football field and had comments from people 3 blocks away,[mostly favrobale]. Perhaps the 515's need a little distance to be appreciated? Bob