I don't know if these have been mentioned, but I have been totally amazed by the sound of these babies:
Graetz BV8070
I use them Open Baffle with a Fostex bullet tweeter and a pair of powered Goodman woofers below 400hz.
They sound utterly modern and balanced. I had to add galvanizing rubber treatment to the bi-cone ring to treat a small amount of midrange peakyness but other than that they cross over with a simple cap to the fostex. A cheap and excellent field coil driver which I daresay would better many €1000.00 modern offering.
Shoog
Graetz BV8070
I use them Open Baffle with a Fostex bullet tweeter and a pair of powered Goodman woofers below 400hz.
They sound utterly modern and balanced. I had to add galvanizing rubber treatment to the bi-cone ring to treat a small amount of midrange peakyness but other than that they cross over with a simple cap to the fostex. A cheap and excellent field coil driver which I daresay would better many €1000.00 modern offering.
Shoog
I repaired a pair of those for a friend. I must say I didn't like them much at all, very old fashioned sounding to my ear.
Shoog
If supporting with a 15" 0 OB or otherwise, I'd be inclined to a smaller FR - as small as 4", but that's just me - always been a fan of the upper mids and top end of that size range.
IIRC, the FA22RCZ needed a much smaller enclosure than the A12P's SuperPensils - I'm not sure where the former now reside.
Bob - care to share the details of your final BSC filter for the 1772? Running them raw could explain what I didn't care for with them - in both a small OB and a mid sized BLH - both designed by a non forum enthusiast.
IIRC, the FA22RCZ needed a much smaller enclosure than the A12P's SuperPensils - I'm not sure where the former now reside.
Bob - care to share the details of your final BSC filter for the 1772? Running them raw could explain what I didn't care for with them - in both a small OB and a mid sized BLH - both designed by a non forum enthusiast.
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Tysen has them. I have a new set here now that need to be worked thru. Something like 60 L sealed (IIRC) for the SEAS, we had them in more like 45 L (recycled KEF Calinda). SuperPensil is about 90 L.
dave
I also like the sound of my 1772, but they do indeed need help. I went the DSP way instead of playing with a bunch of hard to get components in my corner of the world. They can surprisingly handle a wide range of music styles.
If you look at the on-axis FR from Visaton, you see a maximum of about 100 dB up high and just under 90 dB at 500 Hz or so. If you listen to a set off-axis you are asking "these are good, but i wonder what a tweeter would add", listen on-axis and it is "ouch, those are hot, too hot".
Adding the phase plug disperses that rise in response, they have a much wider, smoother, even HF response (you can go from side to side behind the listening couch in my room and the top changes little).
The measured sensitivity is 89-90 dB.
dave
Adding the phase plug disperses that rise in response, they have a much wider, smoother, even HF response (you can go from side to side behind the listening couch in my room and the top changes little).
The measured sensitivity is 89-90 dB.
dave
Attachments
Cheers Dave
What I was looking for is a before & after mod in room frequency sweep. The only before & after measurement of the effect of those dimples I have seen is by Bob Brines. He measured that there was a shift in the fundamental peak of a non linearity in FR. That it altered the sound subjectively a little more than the measurements would indicate. Using completely different methodology and dammar goo Troels Graveson came to similar conclusions with his coating experiments. My own experiments with urethane, solvent, beeswax coatings on a pair of vintage 8in Plessey extended range bass/mid. Concluded the sonic signature was altered and measured better. Lower Fs and smoother & lower top end roll off but didn't sound subjectively much better. My point here is that until people like yourself actually start measuring the before & after effect of these mods not only on Frequency reponse & TS perameters to see if some measurable pattern of response alteration emerges that is predictable across the myriad of driver sizes and cone materials not to mention suspension types and total moving mass we will continue to be flying in the dark. And people will continue to challenge the veracity of the conclusions reached.
Cheers
What I was looking for is a before & after mod in room frequency sweep. The only before & after measurement of the effect of those dimples I have seen is by Bob Brines. He measured that there was a shift in the fundamental peak of a non linearity in FR. That it altered the sound subjectively a little more than the measurements would indicate. Using completely different methodology and dammar goo Troels Graveson came to similar conclusions with his coating experiments. My own experiments with urethane, solvent, beeswax coatings on a pair of vintage 8in Plessey extended range bass/mid. Concluded the sonic signature was altered and measured better. Lower Fs and smoother & lower top end roll off but didn't sound subjectively much better. My point here is that until people like yourself actually start measuring the before & after effect of these mods not only on Frequency reponse & TS perameters to see if some measurable pattern of response alteration emerges that is predictable across the myriad of driver sizes and cone materials not to mention suspension types and total moving mass we will continue to be flying in the dark. And people will continue to challenge the veracity of the conclusions reached.
Cheers
I measure T/S all the time (what i use to do pair matching) -- changes are consistently less than the unit-to-unit variations. FR plots will show little or no change from the spots, i do not yet know of a measure that shows what that does, but blind tests do show a real difference.
A FR plot would show the difference with the phase plugs. I don't have any.
dave
A FR plot would show the difference with the phase plugs. I don't have any.
dave
Thanks for the reply Dave.
This is the last response I'm posting re this subject as it is getting off topic. I know that any measurements you may have will only be relevant to your methodology & listening environment but is there a chance you might let the rest of us see them? Lastly any link to the method/results of those blind tests?
Cheers Mark
This is the last response I'm posting re this subject as it is getting off topic. I know that any measurements you may have will only be relevant to your methodology & listening environment but is there a chance you might let the rest of us see them? Lastly any link to the method/results of those blind tests?
Cheers Mark
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