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Circlomanen
Semesterfirare
9880 Posts |
 Posted - 2005/08/13 : 20:51:17
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Steve-ponken på Decware håller på och utvecklar en ny inkarnation av Imperialhornet men mindre och med djupare bas.
Här är en liten bild. Man kan se den lite i bakgrunden.
" After a year of listening to these as subs I can safely say I've never heard better. Cleanest 20 cycle notes I've heard to date. Run them full range with no crossover in parallel with various speakers and never hear them. Also built a pure class A triode push pull sub amp just for them that runs either full range or with an 18 dB cut at 70 Hz. Both work seamlessly with every speaker I own."
Och
"I call it the Decware Imperial/SO for Sub Only. This pair is not in any way meant to be an improvement or replacement for the original Decware Imperials all over this forum. I built this pair to replace the original pair I showed at Decfest 2003. Since I knew I was going to use them as subs only and for my own personal use I decided three things were in order. 1)Lower tuning, 2) Single driver, 3) Less material.
The idea started by duplicating the WO32 where the driver front cone is loaded only a couple inches from the panel. If you are not familiar with the WO32 it is a bent horn flare that tapers down to nothing. The driver is loaded in one side of the taper as far down as possible.
This had the expected results - very fast. On PA drivers with a high FS of 45Hz and lots of midrange output to 5KHz you got a very live sound when running the driver full out with no crossover. On the same driver used in the original Decware Imperial the results were similar but with lower bass and a heavy roll off at 500Hz. I tried both of these drivers purely in the interest of science knowing they were too stiff for this design.
I wanted a low fs around 25Hz or less, with a fairly high VAS since this driver will see a sealed cavity unlike the original Imperial. I used a pair of old hi-fi woofers from a pair of 2nd order Magnavox speakers from the late 60's.
After spending some time listening to the hi-fi woofers with and without active crossover I began to realize that like the original Imperial when you crawl into the mouth of the horn you still hear traces of high frequency content above the 600 Hz point where the waves stop bending. (Especially without crossover, but even with 12dB of cut)
It dawned on me that ideally no sound above 600 Hz and in this application ideally no sound above say 90 Hz should ever live inside this horn flare. This would be largely impossible because even a 24dB crossover is only a 24 dB cut ... 120dB - 24dB, yea you can still hear some highs in the horn flare.
I then decided if the horn flare was a hemholtz resonator then it would only resonate at it's natural frequencies and nothing higher. It was at that point I removed the solid front from the new design to start testing the theory. Without the front, a slot develops next the driver (on the same plane) and the driver has much less of an idea that it's involved with a horn. The horn which begins with the slot simply resonates sympathetically from the excitation of the driver. Now crawling into the mouth of the horn you hear only pure clean low textured bass with zero high frequency content.
Taking it to another level I wanted to refine the slot and its location for better coupling and at the same time bias the wave front of the driver to become more active on the slot. The "Karson" shape is designed to manipulate the air pressure between the driver and the solid front panel to offset the taper. It also bias the wave front that escapes to blend better with the wave front exiting the mouth of the horn.
The final result did indeed take it to another level. Glass smooth, effortless deep bass where the frequency balance is tilted from a high at 20Hz to about -6dB at 80Hz. This is some of the richest bass I've ever heard."
Detta verkar väldigt intressant!
Principen bakom är ganska radikalt nytänkande och spännande.
Även om verkningsgraden inte lär vara spektakulär så bör man nog kunna få ganska spektakulär bas ur en sån.
Steve verkar ha ganska bra öga för kapabla basreproducenter, och detta lär inte vara ett undantag.
Nått jag lär prova nån gång. |
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