Yep, I read the exponent wrong for Alnico. It was aliased and looked like a -8 without zooming in. It should be:
Electrical resistivity:
Alnico: ~50e-6 ohm*cm
Neo: ~150e-6 ohm*cm
Ceramic: ~1e6 ohm*cm
Aluminum: 2.6e-6 ohm*cm
Copper: 1.7e-6 ohm*cm
So neo is only 3x more resistive than Alnico. Alnico is ~20x more resistive than aluminum.
Soongsc, I appreciate your ideas but have spent enough time with the TD15M. It's a great woofer but not best for my specific application.
The TD15M accomplishes admirably what it was designed for: high output levels at low THD and extended HF response (for a 15" woofer). The cone shape and phase plug are an integral part of this. John even made the phase plugs longer after finding that doing so yielded greater HF extension. Because of the full-length faraday sleeve, less impedance variation is seen by the amplifier than with conventional woofers.
The stout spider is part of the TD15M's over-the-top ruggedness, but it is one of several design characteristics that keep it from being right for my system.
On the other hand, I couldn't be more satisfied with the performance of the AE TD15H and PR15-700 passive radiators in the active bass enclosures. Again, they do exactly what they were designed for, an application that meets my needs.
Even without shorting rings, the GPA 416 alnico sounds fantastic in the upper boxes, so I'm all set.
Gary Dahl
The TD15M accomplishes admirably what it was designed for: high output levels at low THD and extended HF response (for a 15" woofer). The cone shape and phase plug are an integral part of this. John even made the phase plugs longer after finding that doing so yielded greater HF extension. Because of the full-length faraday sleeve, less impedance variation is seen by the amplifier than with conventional woofers.
The stout spider is part of the TD15M's over-the-top ruggedness, but it is one of several design characteristics that keep it from being right for my system.
On the other hand, I couldn't be more satisfied with the performance of the AE TD15H and PR15-700 passive radiators in the active bass enclosures. Again, they do exactly what they were designed for, an application that meets my needs.
Even without shorting rings, the GPA 416 alnico sounds fantastic in the upper boxes, so I'm all set.
Gary Dahl
Gary, I have tried to look for more data on the TD15M. Apparently lots,of people are trying to get them onto a Klippel system as Google shows, but nothing out in the open yet. Although AE seems to be listed as a Klippel user, they have not shown any data either. Could be they have different design goals not in line with home audio. Pro audio definitely need ruggedness in most applications to handle the unknown.
Henry, I didn't consider the Kappalite 3015. It does look interesting, but I noticed that it doesn't reach very low in a sealed alignment.
Speaking of Eminence, in 2003 Lynn and I did some interesting modification experiments with Klipsch Chorus speakers, which had 15" Eminence woofers. The bass performance of these speakers was very impressive, and actually provided some of the inspiration for the Beyond the Ariel project in the first place.
I definitely considered using the Chorus' woofers in the new project, but their FR was too lumpy.
Gary Dahl
Speaking of Eminence, in 2003 Lynn and I did some interesting modification experiments with Klipsch Chorus speakers, which had 15" Eminence woofers. The bass performance of these speakers was very impressive, and actually provided some of the inspiration for the Beyond the Ariel project in the first place.
I definitely considered using the Chorus' woofers in the new project, but their FR was too lumpy.
Gary Dahl
Hi Gary,
thanks for the feedback. im using a single 3012LF in vented with my 3way, fantastic bass, in a way that its like listening to pro and hifi driver blended
.
im interested to build a 2way with 15" and Mr. Le Cleach's (may he Rest in Peace) horn by Martin Seddon, as i got a chance to measure the AH-390 and its very very impressive.
The reason i asked about kappalite, shipping is not too bad to Aussie as its neo motor and I couldnt find any other neo woofer candidate (well perhaps FaitalPro) that have similar response with kappalite in vented. or can always go Sealed with multi subs
cheers
henry
thanks for the feedback. im using a single 3012LF in vented with my 3way, fantastic bass, in a way that its like listening to pro and hifi driver blended
.im interested to build a 2way with 15" and Mr. Le Cleach's (may he Rest in Peace) horn by Martin Seddon, as i got a chance to measure the AH-390 and its very very impressive.
The reason i asked about kappalite, shipping is not too bad to Aussie as its neo motor
and I couldnt find any other neo woofer candidate (well perhaps FaitalPro) that have similar response with kappalite in vented. or can always go Sealed with multi subs cheers
henry
The reason i asked about kappalite, shipping is not too bad to Aussie as its neo motor
I can relate -- you probably know that the AH-425 was designed to be the largest horn that should be shipped from Aussie to the US at reasonably low cost.
Good luck with your project and let us know how it comes out!
Gary Dahl
FWIW, even though that thread is so clumsy (I was just learning how to measure drivers!), I don't really have anything to add after a couple years of learning and still owning those woofers. Well, except maybe that I now have a better appreciation of the various problems all 15" drivers have over 1kHz.
speaking of ....... some copper over AlNiCo , ages ago
Philips 9710/
that's not the only one
I still have some ancient AlNiCo 12" philips with shorting ring in form of Al plate (around 4mm thick) glued on top of central pole/choke
Philips 9710/
that's not the only one
I still have some ancient AlNiCo 12" philips with shorting ring in form of Al plate (around 4mm thick) glued on top of central pole/choke
JBL used pure silver shorting rings on Alnico drivers decades before they switched to ceramic. In a shorting ring all that matters is the resistance of the ring. With silver you need less material than with copper or aluminum. There is nothing "magic" about the material, but "Pure silver" sounds so cool!! "24 kt. gold" rings would sound even better.
Why would gold be better when it has greater resistance? It's only advantage IMO is corrosion resistance which is why good connectors are gold plated. Sadly most are nothing more than a thin cosmetic wash which is more for cosmetic / marketing than function.
Blasted batteries are dead again, off to the store.
Heard they shutdown Indy. Wifes sisters place is -45 and parents it's -35. Looks like Alaska across the midwest. Here it's in the 50's with the temps dropping to the low thirties. Freeze risking strawberry and tomato crops. I'm sure to see a few parka's tonight. The locals can't handle the cold lol Me, sheit lived in the UP of Michigan for three winters qualifies for Siberia
Will counter the locals Brrrr it's sooooo cold out with working in temps >-135° colder, this ain't sh*t!!!
Earl and all affected, stay warm
Heard they shutdown Indy. Wifes sisters place is -45 and parents it's -35. Looks like Alaska across the midwest. Here it's in the 50's with the temps dropping to the low thirties. Freeze risking strawberry and tomato crops. I'm sure to see a few parka's tonight. The locals can't handle the cold lol Me, sheit lived in the UP of Michigan for three winters qualifies for Siberia
Will counter the locals Brrrr it's sooooo cold out with working in temps >-135° colder, this ain't sh*t!!!
Earl and all affected, stay warm
While I agree silver is better it is insignificant A few percent. Anybody who tells you otherwise is fooling themselves The only advantage silver offers is contact resistance as silver oxide is conductive. The practice of longcrystals in LCOF copper may actually make copper better against standard drawn silver wire. You will hear no difference.
What it would take
Proper miking would go a long way, regardless of what system you listen through.
My system often provides both a "you are there" and "they are here" experience, but it is highly dependent on the recording expertise and varies dramatically from one recording to the next.
On a side note, it would be enlightening to know how much money is being spent chasing this ultimate euphonic setup over the years, including time and measurement equipment, or does anyone even care??
temperature hit -4F last night here, with windchill at -25 - -30... brrrrrrrrrrrr
John L.
Proper miking would go a long way, regardless of what system you listen through.
My system often provides both a "you are there" and "they are here" experience, but it is highly dependent on the recording expertise and varies dramatically from one recording to the next.
On a side note, it would be enlightening to know how much money is being spent chasing this ultimate euphonic setup over the years, including time and measurement equipment, or does anyone even care??
temperature hit -4F last night here, with windchill at -25 - -30... brrrrrrrrrrrr
John L.
A correctly working playback system ... which means that the dynamics of the recording are rendered sufficiently accurately, at the right volume levels. Irrespective of the recording quality, a piano should come through convincingly as a piano - I noted at the recent hifi show in Sydney that there wasn't a single decent rendition of piano - those that tried it were just "wet", very limp wristed sound, no guts to it ...