|
Audio Asylum Thread Printer Get a view of an entire thread on one page |
For Sale Ads |
In Reply to: Re: Euphonic Compression posted by RandyB on November 13, 2002 at 17:30:51:
Might be zobel/notch filter time for your crossover strategy. TC
Follow Ups:
Hi, TC:Thanks for the Zobel / notch filter ideas . ..
When I started this project, I was just going to use a cap on the tweeter, let the woofers run full range . . .. design creep has added attenuating resistors on the tweeter, a coil on the woofers, 3rd order for the Ravens, possibly zener diodes, now I'm considering Zobel and notch filter . . . . Maybe I'll call the final design "Topsy", it just grew . . . . . .
Your still here? You reveal more of your project every post which is helpful since
I don't know you. :) I would have presumed the Zobel was all ready in place.
That would have been my second move. The first being SPL check for HF beaming
which is obvious at higher volumes. I know the Alpha 6 tends to have a rising response
and will beam around 4k. It also needs a Zobel to stabilize it.
A recessed dome has beaming written all over it. :).
I found this very annoying with near field listening. In my own design, I prefer the slot dispersion
like a Selenium 320 for near field, with a carefully calculated Zobel, will have smooth Hi
end no matter how loud it is. Then issues of electrical phasing and step baffle come next.
The people over at HI Efficiency Asylum and PI forum deal with this all the time. Maybe
post there since this is the rant forum so far :) Later, Art
Hi, Art:I have been posting on Hi-Efficiency forum in the beginning stages, now I'm down to the 2nd and 3d order design issues, the basic designs are completed and I'm refining things, so I thought I'd see what the Propeller Heads think about a few issues, to get a fresh take on things . ...
Euphonic compression is used by several tube amplifier manufacturers to produce a "retro" sound, I was interested in finding out if I could put in just a little compression to get a "fat" sound, with the added benefit of maintaining a flat frequency response between the woofer and tweeter on the 1-2% of the loudest transient peaks.
I didn't want to use Zobels in this project, since these loudspeakers are designed to be used with flea-powered tube amps (and ss up to 100 watt rms), and I want to minimize power loss in the crossover. I originally wanted to use just a cap on the tweeter, and let the woofers run full range, but high frequency cone breakup and too much overlap forced me to add a coil on the woofers . .. I'm concerned that if I add a Zobel, it will suck too much life out of the few watts available on the lowest-powered SET amps, like 2A3, 300B, PX25, for example.
Hello Randy, I found that the Zobel is very much needed in hi efficiency just to
stabilize the impedance so the x-over can operate properly. Its like taming the beast.
hi efficiency is the only way to go in my opinion but the raw drivers are a bit ruff and
need some tlc to integrate them with each other. The stabilized impedance I would see
as an advantage for low power set, because set seems vunerable to impedance shifts.
Just MHO. Others know more...
Hi, Art:Thanks for the info re Zobel benefits, I'll definitely include Zobel topologies in the iterative design process, see if it leaves enough "life" with flea-powered amps . .. and how it improves driver integration and overall presentation . ... could be a desirable trade-off, fer sher!
If anyone out there has used a Zobel with flea-powered amps, please let me know results, if this can be done without making things too "polite", and if so, best practices for implementation . ..
This post is made possible by the generous support of people like you and our sponsors: