Re: Altec 511B Measurements
Posted: August 14th, 2016, 7:52 am
I have an ACO Pacific 7012 mike plus pre-amp and power supply that you can borrow as a reference. Here is a graph of the response:
Tom
Tom
DC Area Audio DIYer's Community
http://www.dcaudiodiy.com/phpBB3/
The later Altec horn drivers with those damned plastic phase plugs and compression caps have a rep for sounding like crap when compared to the originals.
Roscoe Primrose wrote:I'm fairly certain that I know less than nothing about anything. Or do I? I don't know anymore..
Roscoe
With the Hiraga crossover circuit and top performing capacitors, the overall sound has a directness, immediacy, timbre, authority, nuance, ease and musicality that engage the listener, and don't let go. Further, these speakers are capable of producing a big sound stage with great width, depth, nuance, localization of instruments and voices and a great sense of space. The Altec Lansing people knew what they were doing.
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full bodied, rich, directly engaging, punchy, present, immediate,smooth, sweet, musical, articulate, and nuanced, with a big sound stage, pin point localization of instruments, and lots of space. The sound stage lies well behind the loudspeakers.
Looking at the smoothed frequency response plot below, and noticing the shelving of frequencies above the 500 Hz. crossover point, one might suspect that raising the tweeter level about 3 dB would give a better result. It certainly would provide a flatter measurement. However the system sounds best with the tweeter set where it is.
Some pro models came with a black plastic loading cap over the back of the diaphragm, which won't make much difference at HF but will at 500hz. I made back covers with a much larger volume and really didn't think it was worth doing again but it did create a somewhat softer midrange.
Jim G wrote:Here's a link to a thread at Lansing Heritage about replacing foam with felt in older compression drivers. Has some links and photos.
http://www.audioheritage.org/vbulletin/ ... light=Felt