Received my W6520R-4 drivers!

[kenny_k]

Re: Received my W6520R-4 drivers!

WHen will these be available for sale to the filthy-unwashed?

+1

[Jeff B.]

Re: Received my W6520R-4 drivers!

Could someone with a pair take a look under the spider to see if the VC former
is metalic or not?

Also, does the former look to be 1.5" roughly?

It does appear to be 1.5" in diameter. However, it's really hard to tell what the former is made of. It's a whitish color and may be aluminum, but also looks like it is coated in something too. Judging by the amount of voice coil extending above the gap I would guess the Xmax as 6-7 mm.

So, you asked them to make a driver in 2009? You couldn't find something that would fit the bill?

[foxfire3]

Re: Received my W6520R-4 drivers!

I had the chance to break in my two drivers with my standard procedure after work tonight. Got the kids to bed and was able to take these measurements. I set my Le measurement to 10kHz instead of 1kHz. Added mass of 20.5 g for Vas measurement:

Driver A:
Re 3.911 ohm
Fs 39.03 Hz
Qts 0.4274
Qes 0.4625
Qms 5.63
Le 0.1509 mH
Mms 22.59 g
Vas 0.5861 Ft^3
SPL 85.18 dB/m

Driver B:
Re 3.867 ohm
Fs 39.14 Hz
Qts 0.4402
Qes 0.4757
Qms 5.887
Le 0.1505 mH
Mms 20.48 g
Vas 0.6466 Ft^3
SPL 85.49 dB/m

Based on the above parameters, has anyone calculated what the optimum size ported and sealed boxes would be?

[PWR RYD]

Re: Received my W6520R-4 drivers!

I'm going to cut down (saw off the original baffles) and repurpose my first RUsher enclosures. When done they should be about 18 liters net. Tuning will be around 38 Hz. I don't have the sim in front of me but I seem to remember the F3 was in the mid 30's easily taking 50 watts and producing 103 dB without exceeding 6 mm of excursion.

[johnnyrichards]

Re: Received my W6520R-4 drivers!

Mine might go sealed, have not made up the old grey matter yet. Have to establish a tweeter first.

[mattp]

Re: Received my W6520R-4 drivers!

I'm going to cut down (saw off the original baffles) and repurpose my first RUsher enclosures. When done they should be about 18 liters net. Tuning will be around 38 Hz. I don't have the sim in front of me but I seem to remember the F3 was in the mid 30's easily taking 50 watts and producing 103 dB without exceeding 6 mm of excursion.

Quick BB sim comes up with sealed .707 of .23 cubic feet, F3/F10 of 73/41 Hz. Vented is .6 tuned to 34, 6mm Xmax not exceeded with 80 watts to 30 Hz at barely over 104 dB output.

[PWR RYD]

Re: Received my W6520R-4 drivers!

Could someone with a pair take a look under the spider to see if the VC former
is metalic or not?

Also, does the former look to be 1.5" roughly?

Pete,

It looks like the voice coil is 1-1/2" diameter for sure. It also looks like the former is wrapped in something semi transparent (looks somewhat similar to rice paper) as I can see the voice coil leads heading down the former under the wrap and the actual voice coil windings wound over the wrap.

Much closer inspection indicates very nice frame quality. Nicer than than the Usher 8945's and the various RS driver's frames I have.

[Jeff B.]

Re: Received my W6520R-4 drivers!

Mine might go sealed, have not made up the old grey matter yet. Have to establish a tweeter first.

Hey Johnny, you weren't at the seminar. You must have got a special exemption, huh?;)

[johnnyrichards]

Re: Received my W6520R-4 drivers!

Hey Johnny, you weren't at the seminar. You must have got a special exemption, huh?;)

An attendee was kind enough to forward a pair to me, a late Christmas present Nice woofer, Jeff - I do not know how extensive your input was but it looks like the money was spent exactly where it needed to be spent and not one dime more. Good example of solid engineering, and (IMHO) just what the doctor ordered for the hobby.

[Jeff B.]

Re: Received my W6520R-4 drivers!

An attendee was kind enough to forward a pair to me, a late Christmas present Nice woofer, Jeff - I do not know how extensive your input was but it looks like the money was spent exactly where it needed to be spent and not one dime more. Good example of solid engineering, and (IMHO) just what the doctor ordered for the hobby.

I didn't design the woofer - the engineers at XXXXXXX did that. And Mark specified most of the general features that he wanted in the driver, so the type of cone, basket, surround, shorting rings, etc, were his call.

I got to measure samples and give some input on what I thought the best trade-offs in parameters were. I was targeting what I felt was the best general purpose woofer for smaller sealed or vented boxes that would appeal to the widest audience and still give very nice satisfying results. I felt like the combination of parameters in this driver were right where I would want them to be.

It's not a Satori or Revelator, but in the law of diminishing returns it's closer than the price would indicate. Plus, it doesn't have the mark-up a lot of those drivers have. I believe if it were coming from Europe it would probably cost twice as much, and we should take that into consideration.

Jeff

[johnnyrichards]

Re: Received my W6520R-4 drivers!

Well, hats off to Mark *and* you, sir. Maybe I will call him later and send him a high five.

[Pete Basel]

Re: Received my W6520R-4 drivers!

Pete,

It looks like the voice coil is 1-1/2" diameter for sure. It also looks like the former is wrapped in something semi transparent (looks somewhat similar to rice paper) as I can see the voice coil leads heading down the former under the wrap and the actual voice coil windings wound over the wrap.

Much closer inspection indicates very nice frame quality. Nicer than than the Usher 8945's and the various RS driver's frames I have.

Thanks Craig,
That is probably Kapton or Nomex I'd guess, and if it is semi transparent
then of course it is likely not metalic.
Edit: Mark told me earlier today that, from memory he thought it was aluminum.
I'm hoping that he is right.
I'm looking at the new Anarchy here and the former also has that same look,
holding it up to the light and it is
also semi transparent and not metal unfortunately. Anarchy has a metal
cone that could act as a heat sink if the former were also metal, it also
looks very well made. I could not convince Kevin to use a metal former.
The earlier Exodus 6.5 also has the similar rice paper look on the outside,
but it is not transparent and from the front (phase plug with no dust cap)
there is clearly a metal former.

Good to hear about the frame, it looks very familiar to me but I can't say
who else might be using it without pulling out a bunch of drivers.

[Jeff B.]

Re: Received my W6520R-4 drivers!

Thanks Craig,
That is probably Kapton or Nomex I'd guess, and if it is semi transparent
then of course it is likely not metalic. I'm looking at the new Anarchy here
and the former also has that same look, holding it up to the light and it is
also semi transparent and not metal unfortunately. Anarchy has a metal
cone that could act as a heat sink if the former were also metal, it also
looks very well made.
The earlier Exodus 6.5 also has the similar rice paper look on the outside,
but it is not transparent and from the front (phase plug with no dust cap)
there is clearly a metal former.

Good to hear about the frame, it looks very familiar to me but I can't say
who else might be using it without pulling out a bunch of drivers.

I posted a similar reply to Craig's, but holding it up to the light I would not call this former transparent. It's pretty hard to see with the way this basket is made, but I can tap on it with a probe and that's why I thought it might be aluminum. I could be wrong though. The basket is very well made, but I have never seen another driver that used one like it. Baskets are used all over the place, so it probably used somewhere else though.

[Pete Basel]

Re: Received my W6520R-4 drivers!

So, you asked them to make a driver in 2009? You couldn't find something that would fit the bill?

I had a preference for 4 ohm so that limited things a bit and I went through
a lot of 6 - 7" drivers including some 8 ohm. I spoke to Kevin also about doing
the Anarchy in 4 ohms but could not convince him. I had an Exodus 6.5" at
that time and told him all the things I didn't like about it, lol! It has a very small
spider, and Xmech is not much for such a large Xmax.

I was looking for Fs in the 30s, about 20 g moving mass, 4 ohms, and not so
large of a frame. Ushers, Scans and even Silver Flute is much more efficient in
terms of frame to cone area. I wanted as much VD as possible, of course, and
a smooth response. I also asked PE for something like the RS180 in a smooth
response soft cone that would have fit the bill - the paper cones are now out
but the moving mass is too low for what I want.
Many drivers don't come close on cone mass, GR Research (11.9g), and even
Satori (12.4g) are just a few examples that come to mind - it just means you need
a much bigger box for a low F3.

I've used phase plug drivers before for midranges but in this application, where
they are pushed hard, I could hear chuffing through the leak around the phase
plug with pure tones - anyone else notice this? I have heard that phase plugs do
not offer much acoustically in larger drivers but I've not heard the theory behind
this. I think the claim was above 5" or so. Don't want phase plugs for this app.

[Pete Basel]

Re: Received my W6520R-4 drivers!

I posted a similar reply to Craig's, but holding it up to the light I would not call this former transparent. It's pretty hard to see with the way this basket is made, but I can tap on it with a probe and that's why I thought it might be aluminum. I could be wrong though. The basket is very well made, but I have never seen another driver that used one like it. Baskets are used all over the place, so it probably used somewhere else though.

I edited my post above to include that Mark said he thought it was aluminum, so
you are probably right Jeff. I'll probably ask him to check before I buy a pair.

Mark has sold some excellent high value drivers in the past, the Eclipse line and
I've spoken to him about them - I think he was involved in the design. I
think they used some simple tricks in the motor that made them much more
linear than the average design from 10 - 20 years ago. So I have a lot of hope
for this driver. I don't know Mark well, other than they're always helpful and
polite on the phone, perhaps you know more about those old woofers?

I'd like to see this woofer, the Silver Flute, and the RS-180 klippel tested. I
believe that the Silver Flute has a very primitive motor.