With all due respect Todd, I believe John Meyer has more experience in this area and he says just the opposite. He uses 3" drivers over 1.75" drivers for lower distortion and 4" drivers over the 3" units to lower it further.Originally Posted by Todd W. White
http://www.meyersound.com/support/fo...op/drivers.htm
Widget
Well, he can take that up Wente, Thuras, Blackburn, Don Davis, Dr. Paul Veneklasen, Dr. John K. Hilliard, Alexis Badmaeff, Bill Hayes, Mark Ureda, Cliff Henrickson, Scott Leslie, Ted Uzzle, and Jerry Hubbard (just to name a few), who have made statements supporting what I said. I don't think all of these distinguished men can be wrong...
Incidentally, you may be interested in a preprint of a paper that was presented at the AES by Jerry Hubbard entitled "Subharmonic and Nonharmonic Distortions Generated by High-Frequency Compression Drivers"
Here's where you can find it: http://www.aes.org/publications/prep...nts_search.cfm
Just go there, enter "Hubbard" in the author name box, and hit enter. Fascinating reading!
For the most part those guys are dead or retired. JBL, TAD, and Meyer are all still in business and discuss in their technical papers how the larger diaphragmed drivers produce less distortion. I'll go with the living.
BTW: You can add Altec to the dead list... please take all of this as quite tongue in cheek. I doubt that we are talking about the same issue here as I doubt that there would be all that much disagreement between my group and yours. In simplest terms the large diaphragms yield lower distortion at higher SPLs since they physically move less to produce the same output. I have not yet read your link, but will.
You're not affiliated with Earl Geddes, are you?
No... but I hear he is still alive.
Widget
BTW: I tried to read Hubbard's pre-print... I am no longer an AES member and don't want to spend the $20. What was the gist?
Widget
Exactly what I've said earlier, and much more...
E-mail me your snail mail address and I'll send you a photocopy.
Why is the world still using those 4" drivers?????
I think this "theory" should be put to the test with modern testing equipment.
I don't have the necessary equipment but maybe someone on this forum would be willing to undertake this testing and end the myth's once and for all.
I would not be so stubborn on this topic, but your stubborness seems to drive my desire to put you to the test!
And I still don't understand why you and JD are pushing the issue on the Lansing forum all the while your comments seem to imply the JBL drivers are inferior.
I happen to use Altec compression drivers quite extensively, I am not a engineer or scientist. But I refuse to cut down one OR the other designs.
They are both great designs, and I like them both.
I just have a problem with your biased opinion.
I apologize in advance if you take this wrong, I am a hobbyist and like to look at the big picture with a open mind!
Regards, Ron
When did I say "JBL"????
And JBL is most well known as a major manufacturer of 4" diaphram drivers.
Or an I the only one that felt that way???????????
Ron
Thanks Zilch,
I was too lazy to dig it up. That is the technical paper from JBL I was thinking of. I have read similar things from both Meyer and TAD as I mentioned. Obviously they are all wrong though since "all of these distinguished men can be wrong..."
I imagine we are talking about different types of distortion or something along those lines, since I doubt the distinguished crowd is wrong and I doubt JBL et. al. is wrong either.
Widget
BTW: Zilch did you read the bit about 1" exit vs. 2" exit drivers as used in two-ways?
Where? Can't find it, 'cause I read selectively....BTW: Zilch did you read the bit about 1" exit vs. 2" exit drivers as used in two-ways?
[Am I good at 1.5"?}
Here you go. I hadn't read that document for quite some time. I guess it doesn't actually say "Hey Zilch, in a two-way design you should use..." Essentially it says a well made 1" exit or 2" exit will exhibit similar HF extension. It is an issue of mass break up which is a power to weight ratio issue.Where? Can't find it, 'cause I read selectively....
[Am I good at 1.5"?}
At the time of this document JBL did not make 1.5" exit 3" drivers... obviously they do now. Todd's comments not withstanding the 1.5" exit 3" drivers should have lower distortion (2nd and 3rd harmonic) than the 1" exit 1.75" drivers, but not be quite as low as the 2" exit 4" drivers. Furthermore 1.5" exit 4" drivers like the JBL 2451 or the TAD 4003 have the lowest distortion.
I have sent Todd a PM with my info and do hope to read Mr. Hubbard's AES Pre-print... it should prove interesting.
I guess we have wandered off-topic a bit, as this was essentially an announcement thread... still interesting stuff.
Todd, if you would like to lend me one of your drivers I could measure it for 2nd through 5th order harmonic distortion and compare it to the JBL 435Be 3" driver and TAD 4003 1.5" exit 4" diaphragm drivers all on the same 1.5" horn.
Widget
Is the JBL 1.5" driver throats and Altec 1.4" throats the same? Or is the .1" difference a matter of concern when mating up to the horns?
I have a pair of 311-60's(wish I had a pair of 311-90's instead but..) and using them with 288C and wondering since 1.4" Altec is the only one I have seen, are they compatible with other folks 1.5" throat horns???
I guess Altec wanted to be unique as everyone else uses 1.5".
Ron
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