cornscala driver Altec VS Atlas

[Jcricket]

Hey folks, I was hoping some of you folks could give me an opinion on some drivers. As you know I am starting to build a set of Cornscalas. I have Bob Crites crossover. It has crossover points at 400 and 4500. The cornscala design uses the k400 horn and the atlas driver from the lascala or Khorn. It is a 16ohm driver if I understand correctly.
I tested the crites crossover with a set of Altec 811 horns and a set of 806a drivers(also 16 ohms) for the mids and used a set of selenium d210ti drivers and h25 selenium horns for the highs. it was incredible.

So the question, Can I use the altecs in place of the klipsch k400 and atlas. The concern would be the crossover point. I think 400hz is considerably lower than the altec drivers can handle. Thoughts?

Also, I then have to question what the specs are on the atlas drivers.

Mark

 

[dc270]

I would use the 811 above 1K personally, maybe even 1.2k!
DC

 

[dc270]

The long throat and general horn design of the K400 horn allows it to xover much lower than the 811- I like the dispersion of the 811 much better!
DC

 

[Jcricket]

The long throat and general horn design of the K400 horn allows it to xover much lower than the 811- I like the dispersion of the 811 much better!
DC

I agree, the 806's on the 811's seemed a bit more open and less harsh. So I guess it is a matter of finding a suitable woofer now and then building a crossover. HINT HINT
Thanks DC
I'll see if I can get the woffer measure thingy from PE ordered tomorrow.

 

[Bonder]

Another option is to use a 511B horn, it can be loaded down to 400hz if that's where you're trying to cross.

511B is quite a bit bigger than a 811 but certainly works well in a Cornscalla

 

[Jcricket]

Another option is to use a 511B horn, it can be loaded down to 400hz if that's where you're trying to cross.

511B is quite a bit bigger than a 811 but certainly works well in a Cornscalla

that is an idea. Would the 806 drivers go that low? I think they bottom out at 500hz

 

[DanO55]

Ditto on the 811s. I run my split at 1200hz on my valencia 846bs and it sounds great to me. I believe Altec had a multiple crossovers unit with switchable 500, 800, and 1200hz built in. Right?

 

[Bonder]

that is an idea. Would the 806 drivers go that low? I think they bottom out at 500hz

I don't believe they'd go that low based on what I've read, considering Bob's crossover is 1st order I wouldn't run the risk... You'd be safer to cross at 600 HZ which would require a capacitor change in your crossover.

 

[AFP1]

cornscala

Try an EV SM120a horn. It loads to 400hz quite nicely and sounds far better than the k-400. Andrew.

 

[bowtie427ss]

Would the 806 drivers go that low? I think they bottom out at 500hz

Provided they have a proper acoustic load in front of them, 806 can be run full range and were indeed used this way in "special" applications.

The lower cut off point is limited by diaphragm excursion which will increase significantly when the frequency goes below the horn's minimum recommended cut off frequency.

Guys running flea power can get away with low crossover points like 400hz on a 511 because they're staying within the physical excursion limits of the diaphragm. I can assure you that a 511 offers no meaningful acoustic load at 400hz. However, the driver can still tolerate this until over excursion occurs.

 

[mhardy6647]

The Atlas is a PA driver.

Another option is to use a 511B horn, it can be loaded down to 400hz if that's where you're trying to cross.

Please discuss. Driver, XO topology, power handling and output below 500 Hz?

 

[Jcricket]

I think it would be a great design to make a psuedo cornscala with the 811/806 combo and a tweet, and a suitable woofer. Xovers at 800 and mabye 6400.

 

[Jcricket]

The Atlas is a PA driver.



Please discuss. Driver, XO topology, power handling and output below 500 Hz?

The atlas may be a pa driver, but klipsch uses them on the khorns and the lascalas(others too I think).

PLUS ONE on driver/xover characteristics - if possible - please!

 

[mhardy6647]

The atlas may be a pa driver, but klipsch uses them on the khorns and the lascalas(others too I think).

Yeah, I know... as a former Cornwall owner. I also had a spare (working) pair of the Atlas drivers I found on the scrap metal pile at the dump -- kept 'em as spares for the Cornies, but later swapped 'em for a whole bunch of 6p14p-ev tubes.

The Atlas drivers are pretty uninspiring.

 

[Bonder]

The Atlas is a PA driver.



Please discuss. Driver, XO topology, power handling and output below 500 Hz?

To clarify, there are multiple folks on the Klipsch forum who run 511B horns with either the Atlas driver or a Altec 902 successfully at 400 hz with 1st order networks at loud volumes. I can't say that I've read that this has been done with an 806 driver, apologies for any confusion. Here's a link regarding the loading of a 511B horn.

http://forums.klipsch.com/forums/t/57602.aspx?PageIndex=2

I've measured my GPA 902 driver via test tones and a rat shack meter and if doesn't seem to go lower than 700 hz, driver is only 2 years old and hasn't been abused so trying to get an Altec driver to reach 400 HZ isn't a given even if someone else has done so... as they say YMMV :thmbsp:

 

[theebadone]

:worthless:

 

[Zilch]

The diaphragm material in the Atlas is what?

 

[GordonW]

The diaphragm material in the Atlas is what?

Phenolic, IIRC.

Regards,
Gordon.

 

[mhardy6647]

Phenolic, IIRC.

Regards,
Gordon.

It is so.

 

[Jcricket]

pics coming soon.

Okay, if the atlas is uninspiring, and I need a driver taht goes down to 400hz or a little lower, what do you suggest - also needs to be 16 ohms to work with the crites xover.