amazing lady friend (!!!!) and devastatingly beautiful "swan song" - here's one singer whom I've enjoyed who for whatever reasons still doesn't seem to be widely known https://www.youtube.com/watch?v=RN4NlLixr-A https://www.youtube.com/watch?v=ful-5_v9gh4 - here's a gal with some presence - ask your friend to sing this https://www.youtube.com/watch?v=uj4Xob9ON-o
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My daughter loves PF. Colleen has seen them in concert more than once. To say I love PF is an understatement.
Keith Jarrett, Charlie Hayden and Paul Motian " Take me back ". That shows things off. Also countless of the same people. Charlie Hayden " For a Free Portugal ". That has the master touch of A&M records rather than DGG/ECM. Joni Mitchel Blue was very magical.
I forgot to say. Bonding the ply and MDF made it slightly concave towards the drive units ( 1 inch or prehaps less ) . The PVA was applied generously and four 5 gallon US water filled buckets as weights to bond it. It might just help ? Both are the same as if planned that way.
Keith Jarrett, Charlie Hayden and Paul Motian " Take me back ". That shows things off. Also countless of the same people. Charlie Hayden " For a Free Portugal ". That has the master touch of A&M records rather than DGG/ECM. Joni Mitchel Blue was very magical.
I forgot to say. Bonding the ply and MDF made it slightly concave towards the drive units ( 1 inch or prehaps less ) . The PVA was applied generously and four 5 gallon US water filled buckets as weights to bond it. It might just help ? Both are the same as if planned that way.
"Muddy Waters Sings Big Bill Broonzy" has been for 30+ years one of my tests for speakers (did discover it til late) - how come many modern recordings don't sound as good as this made in 1960? - even after digitizing and data compression its good
https://www.youtube.com/watch?v=TOw41UhmYzk
https://www.youtube.com/watch?v=TOw41UhmYzk
FWIW, my Fane Sov. Pro 12-500s have "Made in England" on the back. I suspect the frame is OEM, though - very similar to Eminence Delta Pro units.
Got them in some old Tannoy cabs (also made in the UK). Just EQ'd them flat and things are sounding very good.
Chris
Edit - Freddi, the post with 3 YouTube links all sounded broken. Overloaded/knackered vocal mics much?
Got them in some old Tannoy cabs (also made in the UK). Just EQ'd them flat and things are sounding very good.
Chris
Edit - Freddi, the post with 3 YouTube links all sounded broken. Overloaded/knackered vocal mics much?
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I bought a Briggs and Stratton powered lawnmower. I suspect it is made in China and put together in the USA. The 12 Lta could be the same.
Here is the 15 inch bass unit used. I took a gamble. It is a spare part for a very low grade plastic box speaker. The photo is slightly wrong as the magnet is larger. It's spec is very like the Alpha 15 sold by Parts Express USA. Matt Farley a DIY member sold me the 12 Lta's and measured the QTX902.539 for me. I will post if I find the results. Pano who put me on to Matt said a Qts over 1 is required for the easiest build. At 1.2 I was lucky, 12 Lta about 0.5. Big thanks to Matt, I don't live far from him and have promised to take my Dynaco A25's for him to try. Matt loves the Snell speaker, I suspect the A25 is a related product. Thanks to Pano also for giving me so much advice. The best bit was the 12 Lta almost don't need a tweeter. The tweeter I bought almost sounds as if it isn't doing anything. If that is true why was I so aware when I didn't have one? I know why but still surprised. The tweeter I chose avoids needing a bespoke amplifier to drive it. Not all can go as loud even if money no object.
15in Driver for QT15 (178.412UK) by QTX, Part Number 902.539UK
Here is the 15 inch bass unit used. I took a gamble. It is a spare part for a very low grade plastic box speaker. The photo is slightly wrong as the magnet is larger. It's spec is very like the Alpha 15 sold by Parts Express USA. Matt Farley a DIY member sold me the 12 Lta's and measured the QTX902.539 for me. I will post if I find the results. Pano who put me on to Matt said a Qts over 1 is required for the easiest build. At 1.2 I was lucky, 12 Lta about 0.5. Big thanks to Matt, I don't live far from him and have promised to take my Dynaco A25's for him to try. Matt loves the Snell speaker, I suspect the A25 is a related product. Thanks to Pano also for giving me so much advice. The best bit was the 12 Lta almost don't need a tweeter. The tweeter I bought almost sounds as if it isn't doing anything. If that is true why was I so aware when I didn't have one? I know why but still surprised. The tweeter I chose avoids needing a bespoke amplifier to drive it. Not all can go as loud even if money no object.
15in Driver for QT15 (178.412UK) by QTX, Part Number 902.539UK
hi Nigel, Goldwood's GW1858 should be suitable (other than disproportionate cost imo vs materials) and is kinda like a scaled version of your 15" woofer - I've run GW1858 in H-frame - moving mass is pretty low and the spider is stiff enough to keep it alright on hip-hop
Goldwood GW-1858 18" Pro Woofer
Goldwood GW-1858 18" Pro Woofer
An externally hosted image should be here but it was not working when we last tested it.
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I didn't find the file I was looking for. This came up with a similar file name. I did it to prove how a high grade amp can be built on tagstrip. The simplicity means it is likely to be stable as it is built eactly as it is drawn. This is real and not simulation. Alas I broke it up as I need the parts.
Even at 20 kHz this is a very low distortion amp. It has a number of special features. The input is bootstraped so as to ride on the ouput of my Quad 33 without the load causing a specification change. The silly bit of this story is I will build a pre amp for a friend at the drop of a hat and use a Quad 33 for myself. The main reason is I can never make my mind up how I would want it to work. I recently did a bit of work on the 33 and find it much better than it should be. Peter Walker had one problem. He was unable to speak with confidence and make people feel they bought the right thing. Instead Quad were a bit snooty. Never with me, even though I gave them a hard time. I was always treated with great respect. A Quad 33/303 with a little bit of care is OK. Denon DL 110 works if gain is boosted. No hiss when doing so! The weak spot of the Quad is HF overload. The DL110 with it's 45 kHz output should be a match made in hell. It very much isn't. It almsot works into M1 setting. I have boosted the gain on mine, it now clips at about 8 ot of 10 and 10 for DGG recordings. The Quad FM3 about 7 out of 10.
I find a two pole filter is not requied. What is good here is the amp has been purpose designed to be unity gain stable if required. I would guess that unique in power amps? The VAS bootstrap might not be needed in this application, nor the input . What I hate about most hi fi engineers is they are lazy to an extreme. Rather than define what they need they add a few op amps and a off the shelf power amp and call it job done. I do it myself 90% of the time. What I don't do is pretend it is Premier Cru. Here in this circuit all that is needed is done inside the amp itself. As a power amp is an op amp why buy an op amp ?
Before I am 80 and I build my preamp the output stage will be also able to drive headphones. A simple complimentary feedback pair output stage using BD 135/136 and 136/135 perhaps? If the heat sink is big enough this should also power speakers up to 16 watts 4 ohms. This will drive any number of power amps. I can also have a more direct route to the output stage loosing the output dumpers if I choose. OPA2604 worked well when I did some tests on this. If I can avoid op amps I will as regardless of what anyone says a simple class A circuit always sounds more real. The Quad is a dreadful circuit. That is until it comes to music. It can be overloaded at the drop of a hat or underloaded. That is the clue. You have to gain set it to what you need. Here is the bad news, To do that you have to use your ears. Some refuse to do this. This includes the feedback capacitor for best bandwidth. BTW. The quality of that capacitor is 10 % the end result. 90 % is it is the right value. Basically go as low at the bass end as you can. Often it passes a point and sounds worse. If 5 Hz is OK or even 0.1 Hz then that is a result. Sometimes it will be 30 Hz. Use nonpolar caps when you can. The higher voltage types are the best. When they don't see 0.4 V the can be Premier Cru over expensive caps. Nikkai and Panasonic.
Freddi. My dream to have an 18 inch. I built these speakers for Colleen. I know she will never have them. I might buy a very cheap large house in Limogues France at about $30 000. If so these will have a home. These speakers are starting to beat hi end stuff. They were built for $300 at retail prices. The speaker that inspired me was by FAL Japan. I am sort of his friend although neither speaks a word of the others langauge. His cost $50 000. His friend says he and I have almost identical engineering histories. I once repaired one of his drive units at a hi fi show. Some German guy said Nige will be the one to do it. Through this I met Lab47 amps. Now that's a product I love . The reason his cost so much is he is no businessman. His 2A3 amplifer is the best amplifier I ever heard and very powerful through his speakers. Better than his friend Kondo when he was alive. How we met is he thrust the circuit for the amp into my hands and smilled. His English speaking friend said " He doesn't count himself as an amplifer designer ". He somehow knew I would know.
I just wanted to add a bit. After repairing the FAL ( re-centering ) we listened. Some other German guy said " Don't bother the measurements are not hi fi." . To which I said " If you shut up and listen you will for once in your life hear about 800 people in the crowd and not just the band. When did you ever hear that before " ? His eyes turned to the sky and he walked away. His big problem was he was 6 foot ? tall and towered 4 feet above the speaker. As in Japan you have to sit on your bottom on the floor if the ready made FAL design. This was the cheapest model, it is very special. When with Heil tweeter it is remarkable. These speakers were for me. I lent them to my Hungarian friend, he died soon after. I never did get to hear them at home. I did get to hear Lab 47 through him.
I just wanted to add a bit. After repairing the FAL ( re-centering ) we listened. Some other German guy said " Don't bother the measurements are not hi fi." . To which I said " If you shut up and listen you will for once in your life hear about 800 people in the crowd and not just the band. When did you ever hear that before " ? His eyes turned to the sky and he walked away. His big problem was he was 6 foot ? tall and towered 4 feet above the speaker. As in Japan you have to sit on your bottom on the floor if the ready made FAL design. This was the cheapest model, it is very special. When with Heil tweeter it is remarkable. These speakers were for me. I lent them to my Hungarian friend, he died soon after. I never did get to hear them at home. I did get to hear Lab 47 through him.
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hi Nigel, one of the craziest things I rigged with a common Eminence 18 was in a rather small Karlson-type topped with a one inch format Smith distributed source horn - it sounded amazing on George Formby despite coming from cd and cheap solid state amp. That type bass in the 1930s plus the snap of the banjolele were great - - do you happen to listen to Formby? (on the open baffle system?)
Formby Reference System - just swiveling the wings on the wood cleats at the top to narrow the starting gap killed the magic.
Formby Reference System - just swiveling the wings on the wood cleats at the top to narrow the starting gap killed the magic.
An externally hosted image should be here but it was not working when we last tested it.
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I had a similar experiance on visiting a friend to give him an old Nakamici BX100 on Saturday. He has some Tannoy Lancasters . He had complained that the top was a bit lacking. I gave him some cheap Motorola piezo clone tweeters. The Tannoys are to my ear not unlike mine before I EQ them. He has no tone controls. I have to say the piezo clones do a good job and have very obvious ultra HF. I will make him a crossover. 6 kHz = 12R + 2u2, 10 kHz = 7R5 . There is some paralell impedance so these values are ball park. What happens is the resitance overcomes the impedance of the piezo element and makes the crossover into simple first order. As these tweeters don't like 3 kHz, it makes a big difference to remove the problem. I might try some myself and feed in at 12 to 15 kHz. Would look rather cool to have an extra unit. I paid $4 for those on special from Maplin ( Our Radio Shack ).
By pure chance the Tannoy's are driven by a similar amp to the one shown before. It is the old Hitachi design with double voltage amp stage and current mirror. Not unlike a very good tube amp. The Tannoy's themselves are very good. Strangely not better than 12 Lta! It seems with my little mod the sound of a paper cup is OK. I cheat by having a tweeter so making three units rather than two. As the brake is about 7 kHz that still is where research says it does least harm. The very weird bit is how much the cheap tweeter I am using sounds like the Tannoy!
If someone says why OB it is simply the bass has more notes and more groups of notes, this is in addition to a very detailed midband. Bass will show more depth in the mid when real music, same here. This will shock you as you think you know a recording and you don't. The most weird is I never heard this on headphones. I know why but now I have proof. I was told we do not hear below 200Hz ecept through the body. This is proof is I never heard any of this through headphones. I have heard more headphones than most have had holidays and own some Stax. What is very weird is how much more music 1928 to 1938 has. Henry Hall is quite dark in a wonderful way, enchanted is the word ( not enchanting ). Woodwind is the thing that is so wonderful. One visitor said do people buy speakers like that ? To which I said NO. The weirdest bit of this is we think we know the 1930's by the sound we usually hear . Do we ?
I showed my dad a photo on my phone. Dad taught me Audio Engineering 54 years ago aged 4. He looked and said " Do they have double voice coils " ? The fact they are baffles got past him when I said " Dad I've made some 1930's speakers ". One recording I was listening to was 35 days older than him, I pictured his mum with him onboard. Already 1931 is getting to be hi fi compared with 1926 The Willaims Sisters. Can they really be acoutic recordings ? Dad was 84 on the 4th April. He and I were out fixing my brothers Bond Bug car that day. So fitting and surely the last time dad and I do our stuff together ? My dad broke the official secrets act with most of what he taught me. Age eight I had a fair idea of how Chain Home and Centimetric Radar worked. Also how Tennis was watch on Chain Home by converting it to a TV feed ( RAF Rye - Winchelsea ). My dad as far as I know was the last person who could work CH. Now the big deal. In Audio subjective beleifs are discouraged. In the RAF my dad was selected amongst many as he could see aircraft in noise, most can not. They worked him so hard when the Iron Curtain came down he was hospitalised due to working 24 hour shifts, no doubt they didn't ask him to do that. He didn't even wear uniform or shave. The minute he was able he was back at work. They just accepted it was that way. The Soviets were testing the Radar at every point. Dad said they simply solved that by putting a transponder in our aircraft which gave codes of the day. Before that some aircraft got through. If you are German and read this my dad gave his all to prevent them getting through. He built Radar with chicken wire and whatever they had, I guess some was CH. To calibrate it they sent out our own aircraft. This meant the radar systems were not 100 %. Better that than none and built at great speed. These were replaced as soon as it was possible. Dad was pretty good in German.
By pure chance the Tannoy's are driven by a similar amp to the one shown before. It is the old Hitachi design with double voltage amp stage and current mirror. Not unlike a very good tube amp. The Tannoy's themselves are very good. Strangely not better than 12 Lta! It seems with my little mod the sound of a paper cup is OK. I cheat by having a tweeter so making three units rather than two. As the brake is about 7 kHz that still is where research says it does least harm. The very weird bit is how much the cheap tweeter I am using sounds like the Tannoy!
If someone says why OB it is simply the bass has more notes and more groups of notes, this is in addition to a very detailed midband. Bass will show more depth in the mid when real music, same here. This will shock you as you think you know a recording and you don't. The most weird is I never heard this on headphones. I know why but now I have proof. I was told we do not hear below 200Hz ecept through the body. This is proof is I never heard any of this through headphones. I have heard more headphones than most have had holidays and own some Stax. What is very weird is how much more music 1928 to 1938 has. Henry Hall is quite dark in a wonderful way, enchanted is the word ( not enchanting ). Woodwind is the thing that is so wonderful. One visitor said do people buy speakers like that ? To which I said NO. The weirdest bit of this is we think we know the 1930's by the sound we usually hear . Do we ?
I showed my dad a photo on my phone. Dad taught me Audio Engineering 54 years ago aged 4. He looked and said " Do they have double voice coils " ? The fact they are baffles got past him when I said " Dad I've made some 1930's speakers ". One recording I was listening to was 35 days older than him, I pictured his mum with him onboard. Already 1931 is getting to be hi fi compared with 1926 The Willaims Sisters. Can they really be acoutic recordings ? Dad was 84 on the 4th April. He and I were out fixing my brothers Bond Bug car that day. So fitting and surely the last time dad and I do our stuff together ? My dad broke the official secrets act with most of what he taught me. Age eight I had a fair idea of how Chain Home and Centimetric Radar worked. Also how Tennis was watch on Chain Home by converting it to a TV feed ( RAF Rye - Winchelsea ). My dad as far as I know was the last person who could work CH. Now the big deal. In Audio subjective beleifs are discouraged. In the RAF my dad was selected amongst many as he could see aircraft in noise, most can not. They worked him so hard when the Iron Curtain came down he was hospitalised due to working 24 hour shifts, no doubt they didn't ask him to do that. He didn't even wear uniform or shave. The minute he was able he was back at work. They just accepted it was that way. The Soviets were testing the Radar at every point. Dad said they simply solved that by putting a transponder in our aircraft which gave codes of the day. Before that some aircraft got through. If you are German and read this my dad gave his all to prevent them getting through. He built Radar with chicken wire and whatever they had, I guess some was CH. To calibrate it they sent out our own aircraft. This meant the radar systems were not 100 %. Better that than none and built at great speed. These were replaced as soon as it was possible. Dad was pretty good in German.
Hopefully I'll have box by Monday.
If I like it, I'm thinking of trying a box with 2 x 12", bottom driver with a 6.27mH inductor, 1 driver at the top, one driver at the bottom.
Maybe if I ran bottom driver without inductor, it would comb high enough to knock down the 1-4khz lifted region. Should leave 4khz+ alone.
Box would be 14" wide x 22" deep x 36" tall, and a wall dividing the area for each driver.
If I like it, I'm thinking of trying a box with 2 x 12", bottom driver with a 6.27mH inductor, 1 driver at the top, one driver at the bottom.
Maybe if I ran bottom driver without inductor, it would comb high enough to knock down the 1-4khz lifted region. Should leave 4khz+ alone.
Box would be 14" wide x 22" deep x 36" tall, and a wall dividing the area for each driver.
for what little its worth, in the little Karlson K12, I preferred Eminence's stage monitor 12cx to stock 12LTA - subjectively greater impact - could be the compression driver's contribution - but think partly its the more powerful motor with a bit more real xmax. (12LTA has 0.08" overhang) My weakest Eminence 12cx has a 54oz magnet, the middle which still has reasonably low mass, 80oz, and the heavy duty with 4" coil, 109oz.
Beta10cx does work well in classic K12. The Fane 12-250TC sounded very good in K12 - but Qtc must have been pretty high.
Beta10cx does work well in classic K12. The Fane 12-250TC sounded very good in K12 - but Qtc must have been pretty high.
you might take cardboard with tape and try partial wings - might not be heavy enough for higher sound levels - or add some air mass with the rear half of an "H" baffle - - - in the old days, burlap or cheesecloth would be stapled behind a driver to get the sound "tighter" - I think that was shown in the little red Sam's book where James Novak of Jensen was explaining his method of sizing reflex vs impedance gather with a test box.