You are right, Steve is not going to advertise how he loaded his transformer. This entire thread is speculation (even that he used an OPT at all), even an electrical engineer cannot read Steves mind. But the concept is simple. You will not get the same results Steve did unless you use the same amp, frequency correcting transformer and modified driver that he has. Go to his site and buy it if you want exactly the same results he claims.
If you want a DIY version then all the info you need to try is right here. When it comes down to it, the concept is L, C and R in series with the speaker, nothing new or difficult to understand. Try it for yourself 😉
I'm sure that Steve will weld those caps .......... now
Your funny, probably just fry off the value 😉 But why bother, he knows that it is his custom transformer that cannot be duplicated, just as it has been with his amps.
I am not in love with the sound of dual surrounds on a driver so I must find my own path.
Decfest, great fun 😉 Steve has been working on his ZEN OB for years. Can't wait to hear his latest.
I did some fr response measurements yesterday. There is absolutely no sign of smoothing of any sort. The same peaks were there, just the response was tilted lower. For me the experimentation ends here. I have no idea how is Steve getting such ruler flat response. I do not believe his data. That fr response is so flat that even good tweeters have hard time to achieve that. Not to mention whizzer coned speakers, which has all sorts of problems there. It must be a hoax.
Before saying its a hoax, let's wait some of us to get and measure them in normal baffles or IB and see.
Must test before judgment , steve has his own way of doing things an has been at it a long time.just go to Decfest and find out.
Here's how Steve did the measurements:
"Tests were performed with 1 watt at a distance of 1 meter using a calibrated microphone and preamp. The test signal was fed to the TORII MKIII which drove the speaker under test. The speaker under test is mounted in a Zen Open Baffle." (see Audiophile Tube Amps and Tube Gear from DECWARE)
Measurements were made using his amp in his OB speaker design in his specially treated listening room and the driver has cone treatment plus a second surround added. So far from a stock driver.
The 'tuning load' is the key to modifying FR. Problem is we don't know is what he uses as the 'tuning load'. Once we understand it, we can apply that to other full range drivers.
Cheers,
Alex
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ok, so it's me against all that mumbo jumbo he writes
I do not believe you can flatten the response of that driver with passive device.
How the hell the passive device knows where the peaks and where the dips are?
I mean, just think about it, speaker is a mechanical device, unless you create something which supplies the signal with exactly the opposite response, you will not flatten out its response no mater what.
If there is such passive device, I would like to see the principle.
Yes, I want to see measurements by the independent party!
See, it does not matter if it "his" room in "his" house, or "his" amplifier and "his" microphone with "his" preamp, all those things are designed to work as linear devices, with flat fr response...all I care about is how he can get that +/-2 dB response from 1kHz to 20 kHz.
I want to see the measurement by independent party, on infinite baffle!
Untill than its a hoax.
I do not believe you can flatten the response of that driver with passive device.
How the hell the passive device knows where the peaks and where the dips are?
I mean, just think about it, speaker is a mechanical device, unless you create something which supplies the signal with exactly the opposite response, you will not flatten out its response no mater what.
If there is such passive device, I would like to see the principle.
Yes, I want to see measurements by the independent party!
See, it does not matter if it "his" room in "his" house, or "his" amplifier and "his" microphone with "his" preamp, all those things are designed to work as linear devices, with flat fr response...all I care about is how he can get that +/-2 dB response from 1kHz to 20 kHz.
I want to see the measurement by independent party, on infinite baffle!
Untill than its a hoax.
It's not even if it is "flat" or not, the real question is deviation from the curve being <some low value. That's very hard to achieve without substantial smoothing of the response in software... so, let's hope someone gets to measure a pair of Decware's offerings and see how that comes out...
_-_-bear
_-_-bear
wonder what Decware used for the transformer back in that tube? Out of curiosity of the Gizmo I've run a 6.3vct transformer controlled with a pot on the 120V winding.
http://www.diyaudio.com/forums/full-range/130679-t-bass-drive-ob-lf-drivers.html
T drive is what they call it. Is this what there using here to flatten out the response
T drive is what they call it. Is this what there using here to flatten out the response
boost circuits transform impedance downwards - some tailoring and damping change could be done with a resistor on high voltage winding and speaker in series with with a low voltage winding. Somewhere I have a few impedance measurements of the secondary for various resistances across the primary - - an optional cap can be used to lift/contour but probably not used - a half turn of the pot in this circuit made a Klipsch Heresy driven with a big solid state amp go from ~normal to mellow and kinda the sound of a classic and underdamped tube amp - it might mimic some bsc
An externally hosted image should be here but it was not working when we last tested it.
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Well, except for the fact Graham states:
"The amplifier MUST be a SS NFB type with good damping figure. It should be 4 ohm continuous rated for use when this circuit drives an 8 ohm driver on an OB, and 2 ohm continuous rated when two 8 ohm drivers are driven in parallel."
And Steve is clearly using his tube amp...
filament transformer
the speaker load would be in series with the low voltage winding. There's some reflected load control available on the high voltage winding. (cap probably not used but general effect was tested). There's some inductance in the low voltage winding.
no capacitor
no capacitor
0.1uF capacitor across the "primary"
the speaker load would be in series with the low voltage winding. There's some reflected load control available on the high voltage winding. (cap probably not used but general effect was tested). There's some inductance in the low voltage winding.
An externally hosted image should be here but it was not working when we last tested it.
no capacitor
An externally hosted image should be here but it was not working when we last tested it.
no capacitor
An externally hosted image should be here but it was not working when we last tested it.
0.1uF capacitor across the "primary"
An externally hosted image should be here but it was not working when we last tested it.
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which is phase and which is impedance?
What happens when you put a cap of 1 ufd in there, how about 10 ufd??
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What happens when you put a cap of 1 ufd in there, how about 10 ufd??
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