WTM Center Channel

[fuzz092888]

It's certainly not a bad profession Assuming you can get a job........

 

[Adam]

Assuming you can get a job........

Getting a job would be easier than dealing with those internet filters. That must be how the Dark Ages felt...

 

[fuzz092888]

That M86 filter is insane. The dumbest part is that all teachers and students have logins so they could easily disable the filter for teachers, but are either too lazy or too incompetent to do so.

Then there's me. A substitute, who can't even get into the building in the morning because all the doors are locked. I need to move I do have a friend in Arizona. Maybe I'll move there and peek in your window in person instead of hiring someone with a video camera.

 

[fuzz092888]

The JW driver had a very strong niche following from 1959 to 1979. The company was sold to volt who did nothing with it and sold the name to musical instrument retailer. I have tried to buy the name back with the help of my brother who is an attorney. However the owners want a ridiculous amount of money.

The driver had a very strong following and sales in the Far East where the driver has always had "cult" status.

Mark Audio of Taiwan have basically copied/developed the driver and it is available from Madisound.

It is the Mark Audio ALP 10. It says it is 6" however they are counting the surround. The diaphragm of this driver and the JW is 88 sq cm. The driver is currently out of stock.

The driver has a standard suspension and not the unique suspension of the JW.

The JW MK II.

The MK III at the end of production has a cone with rolled rubber surround.

The T/S parameters of the Mark Audio ALP 10 and the JW are almost identical.

Both have an F3 of just below 90 Hz in a .25 cu.ft box and an F3 of 47 Hz in a 0.5 cu.ft vented box.

The JW is a slightly lower Qts driver and sealed the Qtc of the JW is 0.5 and essentially non resonant. The ALP 10 is 0.615.

The ALP has twice the power handling, but is 2 db less sensitive.

I have been tempted to buy a pair of Mark Audio ALP 10s out of curiosity, but never got round to it. The driver is however highly regarded.

I forgot to ask, does this require any type of filters or resistors at all in the sealed box you mentioned or does it get wired directly to the binding posts?

Thanks again.

 

[TLS Guy]

I forgot to ask, does this require any type of filters or resistors at all in the sealed box you mentioned or does it get wired directly to the binding posts?

Thanks again.

Directly to the binding posts. No electrical components at all.

 

[alphaiii]

I'm guessing the Markaudio Alpair-7 is just too small of a cone to work in this case.

 

[fuzz092888]

I'm guessing the Markaudio Alpair-7 is just too small of a cone to work in this case.

I guess it would just depend. It's listed as a 4" driver, but if you look at the measurements it's really like a 2-3" cone. I'm guessing it wouldn't be nearly big enough to provide enough SPL's for a medium-large space or take a lot of power. As always I defer to TLS for the final word.

 

[alphaiii]

I guess it would just depend. It's listed as a 4" driver, but if you look at the measurements it's really like a 2-3" cone. I'm guessing it wouldn't be nearly big enough to provide enough SPL's for a medium-large space or take a lot of power. As always I defer to TLS for the final word.

Good point. Plus it seems the useable excursion on any of these drivers is limited, and they are not to be driven to rated Xmax continuously...

Some interesting discussion about the Alpair-10 here...
Measuring Mark Audio Alpair-10 gen-2

 

[fuzz092888]

I wonder if the JW module has the same limitations as the MA drivers. There are a lot of "you must do this or your warranty is void" for those drivers. I'm guessing a lot of those issues wouldn't be as big of a deal in a center speaker since it would mainly be used for voices.

 

[TLS Guy]

I wonder if the JW module has the same limitations as the MA drivers. There are a lot of "you must do this or your warranty is void" for those drivers. I'm guessing a lot of those issues wouldn't be as big of a deal in a center speaker since it would mainly be used for voices.

Interesting. That 4" diaphragm ALP 10 does not look as good as the original JW.

We never marketed the JW module in the USA as this has long been a rock driven high spl market.

The module was not limited by the suspension excursion and compliance. It always was limited by the physical properties of the cone, which will "oil can" if you drive them hard with a constant thump, thump, thump. The cones are basically foil and if allowed to fall in the air, they fall like a feather.

I suspect the Mark Audio has a somewhat tougher cone, as it has a rise in output above 8 K and is ragged. The JW has a slight gentle roll off above 6 kHz. It does sound a little recessed, but is the only full ranger I know that is not shouty.

One used as a center in my system at Eagan has plenty of power to do the job as a center in that environment crossed over at 90 Hz, which substantially reduces the chance of "oil canning'". My measured sensitivity is 88.5 db 1 watt 1 meter. There are no crossover losses, so this is very reasonable sensitivity.

If used sensibly however you can get a lot of uncolored bass from these drivers. I put a 2.0 system together for Afterlife 2 after he was wiped out by Sandy. I was playing some choir and organ music through a pair in 0.5 cu.ft. ported enclosures, and an organ peddle suddenly made the windows rattle.

I noted in vinyl news he has been posting about all the vinyl he has been buying, so I figured he was putting the system to good use.

This is his impression of the speakers with one 4" cone per enclosure.

I truly am enjoying it TLS. The speakers sound so real and not colored like a lot of speakers made today. The only thing I want to add Is a sub and I'm sure it will shine even more.

Basically the speakers were developed to compete with the Quad EL 57, which shook the foundations of audio, being the first truly tonally accurate speaker.

I regard the JW module introduced in 1959 as the first truly accurate moving coil driver.

The spl. generated by a pair of JW modules was very comparable to the Quad ESL 57.

I won't deny that both had reliability issues when pushed. To get lasting pleasure from both required a degree of that rare commodity, common sense.