Altec 290 series drivers

[Rockets]

I have limited knowledge on these (obviously), other than they're rated at 100W, phenolic diaphragm, bandwith of 300 to 8Khz, and have a 114db output.

Can anyone tell me what difference or improvements were made with each revision C thru L? Anything significant where one would want to avoid certain models? What about the impedence...is there any reason a 4 ohm, 8 ohm or 16 ohm unit won't sound essentially the same IF the proper changes are made in the cross over?


Thanks, appreciate the help.

[mbenterprizes]

Which letter series do you have? I have the "D" series with Peerless 15045A line matching transformers With the 15045A's it will go from 30 ~ 100 Watt or 70V input, With a 4 or 8 ohm out. These were obtained from a military base that were being used for out door playing of Revele and Taps. This was played in the morning and then in the evening. As for matching the cross-over, it would be more important to match amp output!

[Rockets]

Actually, I don't own any. I was looking for a driver that would go down to 300hz and these fit the bill. Problem was there are so many of this models 'family' to choose from and I don't know the differences between them.

Thanks.

[Todd W. White]

The Altec 290 drivers are all very similar - the diaphragms never changed, to my knowledge.

The differences usually followed the improvements of the 288.

The last version, the 290-L series, had a large ceramic magnet and a Tangerine radial phasing plug.

The most significant thing about the 290 is that it has the large pot casting on it, which lowers the mechanical resonance of the driver to a point below crossover. This is important, because it means you don't get a bump in the frequency response in the audible band.

Now - if you are wanting to use this in home hi-fi, it will do VERY well on the right horn (my favorite is the Altec 311 series) crossed over at 300, and going up to, say, 8 kHz. Above that, a 902-type driver, specifically the MR902-16HF, would be nice.

New drivers of this type are still available....

[Rockets]

Thanks Todd, that's what I was looking for.

Prior to my post I had an opportunity to obtain a pair of the 311-60's for $175...which is no longer there. This may or may not be a good thing. After doing some measuring, the 60's dispersion is less than optimal for my room, and the 90's are too wide for my project. I have since come across the spec's and plot of some JBL cones which will work quite well, but I really wanted HORNS!! LOL!

What to do...what to do....

Thanks again for the help.

[Todd W. White]

What dispersion pattern are you looking for?

[Rockets]

At least 90 degrees. I plan on building a modifed Lascala, with a 300hz crossover and was trying to keep the 24 inch wide cabinet.
I think I may have found another lense that may work. Unknown manufacurer, but is 24" wide, looks like a 90 X 40 Bi-radial. Unfortunately it takes a 1" driver. ( If push comes to shove, I know I could adapt it, but would rather not.

Just for S&G's how much $$$ do the 290's run new or rebuilt?

Thanks

[Todd W. White]

I don't know if you are aware of this, but there were two different models of the 311 horn: the 311-60 (60x40), and the 311-90 (90x40).

One of the best sounding sectoral horns ever designed or built, the 311-90 might be just the ticket for you...

I know a guy with a couple of pairs. One pair, if memory serves, is brand new. Of course, they never wear out, so new is not necessary, unless you just WANT new ones...

To get a 290 rebuilt by Great Plains Audio is around $85.00, as I recall, plus shipping.

New ones are in the works....

[Rockets]

The 90's would have been GREAT!, and I wish I could use them! Unfortunately, they're 28" wide. I'd have to build a cabinet almost 30" wide to accomodate them and I was really trying to stay within 24". Doing so will prevent me from reinventing the wheel on a number of issues!

Appreciate the thought though.

On another subject...and probably the wrong forum...but do you have any knowledge or thoughts about the Eminence APT-50 Super Tweeter? The plot on it is pretty **** flat, but I don't see many people using it and wondered why! They don't provide plots on harmonic distortion which may be a reason.

Thanks!

[Todd W. White]

Well, let's see...

If you are looking to use the 290 driver, but want to go down to 300 Hz, you could consider an Altec 203B, but at around 32" wide, they might be too big to fit into your width requirement...

You do have another option - have new horns custom made for you: I know of a fellow who can do them in sheet metal, just like the 203B. If you are interested, I could see what the size would be...

The 203B is a nice sounding horn, by the way...

No idea as to your question about the Eminence product.