9' tall and 12' wide..... Altec A1 V.O.T.T.

[RacerXtreme]

Anyone ever listen to one (or two) of these ? I've got two A2's or four A4's and have a line on another pair of cabinets. If I can pick them up for a reasonable price I'll have two A1's.........with wings.



Based on the characteristics of the exponential horn in an Altec 210 V.O.T.T. cabinet, and the internal volume of the box (which is too big), is there a way I can calculate the frequency at which the low end will start to roll off when set up in an A1 configuration - i.e...... three 210's w/ six 15" woofers per side ?


Wonder what my wife will say as I'm unloading another pair of cabinets in the driveway ?

It's not gonna go over well, but she's been a good girl lately............I think I can talk her into it.


c-ya


Guy

[GM]

Greets!

Didn't we already cover this on the Altec forum awhile back?

GM

[Cal Weldon]

Guy,

You're gonna beat that horse to death.

I say go for it. You'll be about the only guy (pardon) with six of those 210 cabinets. I'm jealous.

Have you checked with the doctor about this? Seriously though, have you got the JBL's in the other 4 yet? How did they turn out?

Cal

[RacerXtreme]

Well...........sort of. I still have some questions that didn't get answered on the Altec site. I wanted to ask here to get some different opinions.

On the Altec site, Jim Dickenson said:

" The heavy JBL woofer in the 210 horn will not produce adequate midrange performance and certainly not any speed or transparency. This is the domain of the light moving mass and underhung voice coil of the 515/165. "


How much "midrange performance" are we talking about when it's crossed over at 500 Hz ? There are times (depending on program material) that I have them crossed over at 200 Hz. Guess I just don't think of "midrange" at those frequencies.

He also said:

"An A2 has a 1M/1 watt rating of about 114 db. The mutual coupling of the 2 210 bass horns is to below 50 Hz at full level! A good 515 with a paper voice coil support handles 75 Watts AES. This gives you a max continuous SPL of about 140 at a Meter, go to 150 for peaks. The JBL unit will handle 500 watts AES, has 98 db 1 W 1M efficiency. Max Spl is about 127 at Max. 137 at peak. It would take the JBL 2000 Watts to get to the same continuous level as the A2 at 300, the speaker simply will not handle the power."

Now if I'm reading that correctly, 2000 watts into the JBL's will equate to 300 watts into the Altec 515's. Say what??? The JBL's have a sensitivity of 98 db and are rated at 400 watts. The Altec 515's are 103 db and rated at 60 - or maybe 75 as Jim stated. There is a difference in sensitivity of 5 db between the two woofers. A difference of 3 db represents a doubling of acoustic power right? If I double the rated power of the 515's (lets say 75 watts for example).........I get 150 watts. If I double that again I get 300. I doubled the power not once, but twice ............. equating to a difference of about 6 db.

So if I stick 400 watts into the JBL's I'm still not going to get the same SPL as 60 (or 75) into the 515's ?

I still don't get it. I ditched the 515's because I wanted to go with a woofer that handled more power. The JBL's obviously do, but will the 5db difference in sensitivity be that much of a factor in getting more SPL out of the system ?


Thanks,


c-ya


Guy

[RacerXtreme]

Hey Cal,....................what's happening?

No, I don't mean to beat it to death, but just want to make sure I'm doing the right thing before I dump a lot of money on 5 more(or maybe 9.....) JBL 15" woofers. Some guys on the Altec site are recommending going with a $640 (each) Iconic speaker instead of the 2225's. That's OVER 5 GRAND in woofers ..........with no boxes.......

It would be just under $7700 if I needed 12. Argh........

I've only got 3 of the 2225's so far. Haven't been messing w/ speakers much lately. Twisted my knee pretty bad. But it's getting better and it's time to start working on the cabinets.

What have you been up to? Come across any good deals lately?

Have a good one.




Guy

[Cal Weldon]

Guy,

I personally don't think the JBL's are going to be a problem in the 210 cabs but I'm no expert so...

Actually no good deals as of late, but I have put together three systems since we last talked I think. One for the bedroom and two for the sunroom. All from the ground up, no premade cabinets. Here's the low level units for the sunroom, front and back

[RacerXtreme]

Woah....

Nice.

How do they sound ?





Guy

[GM]

Greets!

OK, I just browsed the Altec forum threads and there's so much BS/misconceptions/ignorance/lack of other design considerations/whatever that I don't know where to begin, but I'll respond to it all over there as my currently limited time permits. I recommend not buying any more drivers and/or 210s till you're in a much better position to make an informed purchasing decision.

GM

[Cal Weldon]

GM,

I think you're right about the JBL's in the 210 cabinets.
Now I've never met Guy, but I think he might think a little like I do when it comes to having some raw drivers. Why not take what you have and put them in some decent boxes?

No it's not matched, you haven't really paid attention to the t/s nor the fact that the boxes are 50 year old technology, but why not just enjoy what you can. Heck, he has them on their sides underneath that awesome race car setup that I think you two have discussed.

I know you're a very learned purist, and I know it must drive you crazy to see this kind of hacking your way through things but when I listen to my PA suff which unfortunately includes only Altec boxes, no original drivers, and I hear the sound pouring out of those things, I can't help but think of your subline "Loud is beautiful if it's clean!". No one ever accused PA tweeters of being cloudy or muffled or very accurate for that matter, but I wondering if it's ok sometimes to break the rules if you are happy with the results?



Please try and forgive me.

Cal

[Cal Weldon]

Guy,

They sound great thanks. Bass is a little sloppy above 5 watts, but I'm using them for the low volume speakers. You know, they scope lousy but they sound a little like the 'loudness' button is on. That's what I was trying for. Make any kind of music sound good really low. I have the coax's and a 15" box for party time.

Cal