Whoa, please pardon if you even began to feel i was referring to others with that .... that would be both rude and arrogant as hell
i meant my intuitive speculations ...you know, like me trying to find ways to rationalize my beliefs...
system 7
sorry (post 70), the finch is a 6db both ways.
"This is what I call an elegant design. One inductor for the woofer, one capacitor for the tweeter. There are other components to correct the response but essentially, it’s a 1st order network."
Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab
and I had to move my cat378 maybe 2" behind the baffle for an eminence b102 10" driver, but perhaps the a26 is much shallower allowing closer to physical alignment.
sorry (post 70), the finch is a 6db both ways.
"This is what I call an elegant design. One inductor for the woofer, one capacitor for the tweeter. There are other components to correct the response but essentially, it’s a 1st order network."
Finch (Morel CAT378 + Vifa PL18W0-09-08) – AmpsLab
and I had to move my cat378 maybe 2" behind the baffle for an eminence b102 10" driver, but perhaps the a26 is much shallower allowing closer to physical alignment.
My apologies, 3 nights with about 1 hour sleep apiece is playing havoc with what passes for my mind these days...
I know the feeling, we're all looking for ways to explain impressions etc. we get when listening & adapt based on what we learn. At least, I think we are!
My apologies, 3 nights with about 1 hour sleep apiece is playing havoc with what passes for my mind these days...
I know the feeling, we're all looking for ways to explain impressions etc. we get when listening & adapt based on what we learn. At least, I think we are!
Very nice Scott, thank you
Hope whatever is taking your sleep away subsides pleasantly and quickly !
Yes I did but it seems that I missed the pictures.
Tweeter: D27TG-35-06
Mid: P13WG-00 8 ohm
Woofer: M26WR-09-08 Also Marked DAL SC-X 10"
This is the later version with all Vifa drivers.
Tweeter is now being made by Scan as Discovery D2606/9220:
ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter
The mid does not seem to be available, I'd consider these in a rough clone:
SB Acoustics SB13PFC25R-08 5" Paper Cone Woofer 8 ohm- ROUND
or: SEAS Prestige ER15RLY (H1455) 5.5" Reed Paper Cone Woofer
Very low cost, needs a notch:
Peerless 830656 5.25" Woofer
Tweeter: D27TG-35-06
Mid: P13WG-00 8 ohm
Woofer: M26WR-09-08 Also Marked DAL SC-X 10"
This is the later version with all Vifa drivers.
Tweeter is now being made by Scan as Discovery D2606/9220:
ScanSpeak Discovery D2606/9220, 1" Textile Dome Tweeter
The mid does not seem to be available, I'd consider these in a rough clone:
SB Acoustics SB13PFC25R-08 5" Paper Cone Woofer 8 ohm- ROUND
or: SEAS Prestige ER15RLY (H1455) 5.5" Reed Paper Cone Woofer
Very low cost, needs a notch:
Peerless 830656 5.25" Woofer
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No comments on the 2.8 ohm resistor in parallel with the midrange cap C4?
Those mids are driven hard.
I normally prefer a 4 - 5" mid but in this case considering how hard they are driven
I might prefer to go to a 6 - 6.5" mid.
The P17 Vifa is available under the Scan name:
ScanSpeak Classic P17WJ00 6.5" Woofer
Has anyone computed the mid and woofer enclosure volumes?
Those mids are driven hard.
I normally prefer a 4 - 5" mid but in this case considering how hard they are driven
I might prefer to go to a 6 - 6.5" mid.
The P17 Vifa is available under the Scan name:
ScanSpeak Classic P17WJ00 6.5" Woofer
Has anyone computed the mid and woofer enclosure volumes?
Seems to me that a good way to modernize designs like this would be to use a driver
like the one used in the KEF Q350 but design a linear phase crossover for the two
drivers. This is the way to fix the poor lobing of 1st order networks. Then also add
a pair of 10 or 12" woofers.
I expect that the KEF tweeter will blow with a 1st order network.
like the one used in the KEF Q350 but design a linear phase crossover for the two
drivers. This is the way to fix the poor lobing of 1st order networks. Then also add
a pair of 10 or 12" woofers.
I expect that the KEF tweeter will blow with a 1st order network.
No, normally C4 without the resistor would be a simple 1st order high pass filter and
a simple way to analyze it is to consider DC, a cap does not pass DC so there is zero
output at DC, then at very high frequency C4 acts like short to pass HF. So the
resistor forms a voltage divider with the driver input impedance, then C4 increases
the output at higher frequency. It is a shelving filter and it _does_ pass DC.
If you simply wanted to level match the mid to the system the resistor would be in
series with C4.
a simple way to analyze it is to consider DC, a cap does not pass DC so there is zero
output at DC, then at very high frequency C4 acts like short to pass HF. So the
resistor forms a voltage divider with the driver input impedance, then C4 increases
the output at higher frequency. It is a shelving filter and it _does_ pass DC.
If you simply wanted to level match the mid to the system the resistor would be in
series with C4.
A DSP active crossover might be the solution for this problem, say 1st order at
2 KHz, then 8th order at 500 Hz with an all pass phase compensation to fix the
phase error from the 500 Hz filter, or just design one of the better phase linear
DSP based designs.
Of course Thiel (CS7 for example) did coax first order systems but their drivers
were not as good as the KEFs from what I remember.
Thanks for the explanation.
I have several Dunlavy speakers.
I have a pair of SM-I’s that I am attempting to make similar to Athena’s...
Built an enclosure with Scanspeak 25w/8565-00 downfiring.
So far used a 14.5 mH for low pass in a basic attempt.
I have read that the Athena, Aleetha, Corinthian, SM-IIIa used no crossover between 10” and
P17. But it seems that maybe need at least a series resistor to drop levels of SM-I.
This is a learning experience for me.
I have several Dunlavy speakers.
I have a pair of SM-I’s that I am attempting to make similar to Athena’s...
Built an enclosure with Scanspeak 25w/8565-00 downfiring.
So far used a 14.5 mH for low pass in a basic attempt.
I have read that the Athena, Aleetha, Corinthian, SM-IIIa used no crossover between 10” and
P17. But it seems that maybe need at least a series resistor to drop levels of SM-I.
This is a learning experience for me.
On another current thread, "ESS AMT.....",
a link to a Dunlavy interview was posted.
Loudspeaker designer John Dunlavy: By the Numbers... | Stereophile.com (thx ginetto61 )
I had read it before always stopping when he started talking about the past, antennas and such. Long been an admirer, way back when he was posting on other forums, and mistakenly stopped reading..
Finally wised up and read the whole thing...
Much to my surprise I learned about the Magnus project he was last undertaking.
Where he talked about using DSP for fine time alignment, very fine EQ's, and being able to separate magnitude and phase independently.....IOW, FIR.
To be used on his already excellent designs, converted to multi-channel active.
His first order designs, and their excellent impulse-step response have been a big part of my inspiration to work with linear phase
(especially since the high SPL type speakers i build don't lend themselves well to first order, and there is no other practical way to achieve first order impulse/step).
I've always wondered if he would embrace the newer DSP tools, or if he felt passive had some intrinsic sonic advantage.
Nice to have that question answered.
Oh, btw, here's a small piece of Dunlavy trivia...
....the headphones he said that he used for comparisons to his speakers...
....the everyday inexpensive sony mdr-7506.
a link to a Dunlavy interview was posted.
Loudspeaker designer John Dunlavy: By the Numbers... | Stereophile.com (thx ginetto61 )
I had read it before always stopping when he started talking about the past, antennas and such. Long been an admirer, way back when he was posting on other forums, and mistakenly stopped reading..
Finally wised up and read the whole thing...
Much to my surprise I learned about the Magnus project he was last undertaking.
Where he talked about using DSP for fine time alignment, very fine EQ's, and being able to separate magnitude and phase independently.....IOW, FIR.
To be used on his already excellent designs, converted to multi-channel active.
His first order designs, and their excellent impulse-step response have been a big part of my inspiration to work with linear phase
(especially since the high SPL type speakers i build don't lend themselves well to first order, and there is no other practical way to achieve first order impulse/step).
I've always wondered if he would embrace the newer DSP tools, or if he felt passive had some intrinsic sonic advantage.
Nice to have that question answered.
Oh, btw, here's a small piece of Dunlavy trivia...
....the headphones he said that he used for comparisons to his speakers...
....the everyday inexpensive sony mdr-7506.
SC-IV caps
Hello, acquired a pair if SC-IV recently to compliment the SC-S2 which I previously ran with a pair of 4312Mk II's . I've had wonderful results maintaining the original crossover circuitry with more modern high grade film caps and inductors on the 4312's and was wondering if anyone had been so brave as to actually tinker with a dun xover with positive results. ie.could using some mundorf, clarity or similar caps with the same specs potentially bring even more beauty to the sound ?
Hello, acquired a pair if SC-IV recently to compliment the SC-S2 which I previously ran with a pair of 4312Mk II's . I've had wonderful results maintaining the original crossover circuitry with more modern high grade film caps and inductors on the 4312's and was wondering if anyone had been so brave as to actually tinker with a dun xover with positive results. ie.could using some mundorf, clarity or similar caps with the same specs potentially bring even more beauty to the sound ?
Old 'n' cranky - I realize this was a few years back, but wondering what direction you ended up going ? what caps? resistors ? inductors did you replace and results ? Your schematic is very helpful. Also wondering if the inductor values are printed on the components or did you test for the values. I wasnt planning on messing with the DCR on mine, but normalizing with a resistor in series to maintain the original circuit. Thanks
I haven’t changed any parts in my collection of Dunlavy speakers.
I am curious about your SC-S2’s....Do yours have 2 x 12” woofers in each cabinet?
I purchased a pair of the Dunlavy spec’d Eminence woofers that were used in the SC-S2’s and built my own. I contacted Eminence and they gave me data sheets (t/s) for the woofers.
They are very similar to LAB12 but with lower fs and power handling.
Once Dunlavy was sold they had some subwoofers that shared the same model # but had different driver configurations. Such as.... an SCS2 can be found with 2x12” and also 1x15”
Very strange...