These enigmas came back into my possession some time ago I gave them to a friend who said he no longer wanted em & do I want them back? Absolutely!
They sounded quite pleasant but the limited power handling of the paper cone tweeters were strangling the potential of the AD 7065 W4 bass/mids.
When one of the tweeters went open circuit opportunity to turn this ugly duckling into a swan was irrepressible.
On hand were a pair of AD 0160 T8 tweeters that were very similar to what they used in Philips motional feedback active studio monitors. Yup!
I had to cut out the old tweeter mounts and make a new baffle mounting plate & glue it in. Advantage being a stronger physically time aligned to the woofer baffle for the new top end. The cabinets required crossmember reinforcing re-stuffing, repainting and the real wood veneer relaquering. The woofer cutouts were back radiused to release any airflow restrictions. All sealing gaskets goo & foam was replaced. The woofers stamped metal frames were damped & 3 Neodymium backing slugs each woke them up from 40 years of slumber. I reserved 1 slug each for the back of the tweeters.
The original crossover was primitive is significant as
understatement of the year. It was thown in the bin with much rejoicing.
I had the components on hand to knock up a much better mousetrap.
Rather than drivel on with all the mods I will give some before & after photos. How does the sound compare to the original?
Well it simply doesn't. Would you compare an edison phonograph with a live concert? THAT kind of better. Always surprises me the unrealized potential hiding in these vintage drivers.
They sounded quite pleasant but the limited power handling of the paper cone tweeters were strangling the potential of the AD 7065 W4 bass/mids.
When one of the tweeters went open circuit opportunity to turn this ugly duckling into a swan was irrepressible.
On hand were a pair of AD 0160 T8 tweeters that were very similar to what they used in Philips motional feedback active studio monitors. Yup!
I had to cut out the old tweeter mounts and make a new baffle mounting plate & glue it in. Advantage being a stronger physically time aligned to the woofer baffle for the new top end. The cabinets required crossmember reinforcing re-stuffing, repainting and the real wood veneer relaquering. The woofer cutouts were back radiused to release any airflow restrictions. All sealing gaskets goo & foam was replaced. The woofers stamped metal frames were damped & 3 Neodymium backing slugs each woke them up from 40 years of slumber. I reserved 1 slug each for the back of the tweeters.
The original crossover was primitive is significant as
understatement of the year. It was thown in the bin with much rejoicing.
I had the components on hand to knock up a much better mousetrap.
Rather than drivel on with all the mods I will give some before & after photos. How does the sound compare to the original?
Well it simply doesn't. Would you compare an edison phonograph with a live concert? THAT kind of better. Always surprises me the unrealized potential hiding in these vintage drivers.
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This is a sketch of the original crossover. The current version runs no series resistor to the tweeter The bass side inductor is .82 the tweeter now .30 the resistor parallel to the tweeter is 27 Ohms 3 Neodymium backing magnets on the AD7065W4 woofers & 1 on the tweeter. Its ALIVE!, ALIVE I tell you! WOOHaaaaaHaaaaaAgh
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Yup Kevin. They are kind of born again. A brand new creature. The old hath passed away! Hallelujah! Listening to them right now with my 12 inch Pair of subs dialed in real nice. I think I will give em a run with my valve amp as I think them & low watt( 14 )triodes will make a good match.
Cheers for the encouragement.
Cheers for the encouragement.
Nice work! I enjoyed reading that. A good project seen to completion given you had a fried tweeter. 
If you didn't know, Troels Gravesen explored these lively old high Qms Danish and Norwegian woofers AND cone tweeters: BLACKCONES
He also looked at the old mylar dome philips tweeter you have used: WWDT. Mylar domes always seem have a rising response at the top end, but are quite acceptable IMO.
If you want a flat impedance for a SET amp, we did something like that here: http://www.diyaudio.com/forums/multi-way/305201-visaton-2-way-tower-monitor-audio-bronze-5-a-11.html#post5070435
I have done speakers with 2" Monacor HT-22 cone tweeters and 3/4" mylar Visaton DT94 domes. They can both work well, IMO. But sound different for obvious reasons on dispersion and the very top end response. It's a great hobby.
If you didn't know, Troels Gravesen explored these lively old high Qms Danish and Norwegian woofers AND cone tweeters: BLACKCONES
He also looked at the old mylar dome philips tweeter you have used: WWDT. Mylar domes always seem have a rising response at the top end, but are quite acceptable IMO.
If you want a flat impedance for a SET amp, we did something like that here: http://www.diyaudio.com/forums/multi-way/305201-visaton-2-way-tower-monitor-audio-bronze-5-a-11.html#post5070435
I have done speakers with 2" Monacor HT-22 cone tweeters and 3/4" mylar Visaton DT94 domes. They can both work well, IMO. But sound different for obvious reasons on dispersion and the very top end response. It's a great hobby.
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Cheers Steve
Yeah big fan of Troels & the nothern climate that keeps him snowed in and as a result enriches everybody's audio understanding. Yeah In relation to the blackcones I have a pair of 30 TV-E's that I am eager to try out
Yup Visatons were my initial choice. Typical no nonsense teutonic enginnering. But the urge to bust out & create something unique was overwhelming. The fine tuning done by ear will take a week or so & I expect more tweaks & subtle adjustments. I try to keep the XO as minimal coponent wise as possible but often in doing so you find you actually loose more than you gain. I relate passive crossovers to like walking a tightrope while juggling marbles. Change one thing and it effects everything else. Yup also agree that mylar domes have a unique sound but with these Philips AD T0160's the rise is just so smoooth & likely assists my aging hearing. Nice work BTW
Cheers
Yeah big fan of Troels & the nothern climate that keeps him snowed in and as a result enriches everybody's audio understanding. Yeah In relation to the blackcones I have a pair of 30 TV-E's that I am eager to try out
Yup Visatons were my initial choice. Typical no nonsense teutonic enginnering. But the urge to bust out & create something unique was overwhelming. The fine tuning done by ear will take a week or so & I expect more tweaks & subtle adjustments. I try to keep the XO as minimal coponent wise as possible but often in doing so you find you actually loose more than you gain. I relate passive crossovers to like walking a tightrope while juggling marbles. Change one thing and it effects everything else. Yup also agree that mylar domes have a unique sound but with these Philips AD T0160's the rise is just so smoooth & likely assists my aging hearing. Nice work BTW
Cheers
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My very first loudspeaker design was built using this* Philips tweeter. It was surprisingly good! (Slightly O/T, but...) The crossover was quite complex, complete with impedance -flattening conjugate networks and frequency-shaping equalisation.
*Reading the Troels web page, it turns out there were several variations on this model. Mine came from a B&O speaker.
*Reading the Troels web page, it turns out there were several variations on this model. Mine came from a B&O speaker.
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