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You're confusing material with size. Altec large format and small format diaphragms are made from exactly the same aluminum alloy, yet exhibit quite different performance bandwidths.Quote:
Originally Posted by robertbartsch
I find it interesting that with the exception of implantable hearing aids, where titanium has a signifigant biocompatibility edge, titanium has been of little use in microphone xdcrs. :)
Gold-sputtered polyester film is what they use on high end neuman condenser micsQuote:
Originally Posted by bfish
...which is just a minor tech advance over the metalized Mylar elements Altec developed in the '40s and continued to use for more than 30 years. :)
Aluminum is the best. Meyer is slowly converting to aluminum Talk Shop With John - The Development of Meyer Sound's High Drivers
Ev is still using titanium and so does JBL except for Their Line Array (Berylium).
Now if I wanted to go into the business again of FOH sound for small venues of 600 to 800 seats I would purchase 4 box of JBL line array for each side with Subs For each side.
Ymaha PM1D mixer one for FOH one for stage and one for broadcast.
Monitors in broadcast truck small JBL LSR and Altec Lansing 604 8HIII.
Stage monitors would be in ear
The 3 way snake splitter.
Fostex Digital 24 track recorders.
Outbord Equipment dbx compressors for low mids if I need to carry my sound further but would rather use delay towers instead and keep everything at an even 90 DB SPL.
Those Titanium phragms have got to go. I love the expression Ice Pick to the forehead.
Chow
With regard to manifolding -
Multiple drivers on the same horn require some sort of apparatus (manifold) to get them mounted up.
Early WE attempts were clumsy - I remember seeing some of them. Straight pipes screwed into threaded hole bored into a plate mounted to the throat of the horn.
Not very good - LOUD, but didn't sound good.
WE then changed over to the multiple-driver throats most here are probably familiar with, which worked pretty well.
Jensen and Magnavox, along with Harry F. Olson at RCA, all tried different approaches - some worked better than others.
The kicker is getting the waveforms to arrive in phase and combine, rather than subtract from the total SPL - in addition, out-of-phase signals sound pretty nasty.
EV tried manifolding several years ago - their "MT" series was heavily promoted and quite popular for a while. Their big problem was they forgot (if they ever knew) that you don't bend high frequencies around corners - especially at 90-degrees - and they had serious sound quality issues.
Jerry K. Hubbard, then Head of Acoustics at Altec Lansing, solved this problem - he divided the vertical diffraction slot on the MANTARAY horn throat into two parts: upper and lower. He then fed each half into the horn in a gentle, sloping manner. This eliminates the problem right angled manifolds had, and resulted in an overall increase of SPL of 4dB, instead of the theoretical 3 dB!
Sadly, this method only works with horns with straight vertical diffraction slots, like the MANTARAY, but it works REALLY WELL!
The modern approach is to use line arrays, which have all kinds of problems that have to be overcome, often using electronic trickery to accomplish it.
Barry McKinnon has an EXCELLENT article on line arrays. Read it here:
Loudspeaker Cluster Case Study
As far as my feelings on Titanium, I appear to be in good company...Meyer also says it produces distortion products.
" Titanium has good high frequency response because it is very stiff but it also has relatively high distortion and tends to fatigue quickly. Pure aluminum has a much longer life cycle but its high frequency response is not so good. Beryllium has a good blend of qualities in terms of efficiency, longevity and frequency response, but it is extremely toxic material to work with and so we ruled that out very quickly. "
I've been saying titanium makes a horrible surround for years, nice to see tests document what I hear. Most European titanium drivers copied Altec's Symbiotik idea.
Personally I find distortion a worse problem than bandwidth...a balanced system in terms of HF and LF...ie if you roll of the HF you have to do the same for LF or it will be bottom heavy...a system like that will sound better than one with a wider bandwidth and much higher distortion.
In the latter case the extra bandwidth actually makes the distortion easier to hear...
Old Guy:
The aluminum diaphragms sound more natural to me also. But, lets hope Readhead doesn't have the yard sale anytime soon, however!
If the aluminum units don't go as high, does anyone know if the "new" acquplased alumium JBL driver is coupled with a third driver - e.g a tweeter? These systems are priced in the statoshere so I haven't followed their specifics.
I always loved their 077/2405 slots and, in fact, I mated a pair to a VOTT system 30 years ago which was a good move IMO. I think they discontinued the slots when the Ti frams were developed; right?
IMHO best single item JBL ever madeQuote:
Originally Posted by robertbartsch
'zactly. Sytems that start to dump ~14-15kHz are only short ~1/2 octave of harmonics (and harmonic distortion). Take that same half octave from the bottom, and you're still at 30Hz, a challenge for most systems to play flat to.Quote:
Originally Posted by Old Guy
I'm wondering if perhaps my wife isn't one of those Titanium models. She can be a mite shrill to the ear and is virtually indestructible. Also like OG I should be top notch by now so that part of the equation isn't working apparently. :)Quote:
Originally Posted by Old Guy