Check out this new 12" driver (2 Viewers)

[Kyle Richardson]

Seth, nothing wrong with the Adire PR15's at all, but I think almost everybody here would agree with me when I say that when you get above 2 pr's it better to go with larger PR's like the 18" Stryke's. Much cheaper too!

 

[Seth_L]

Seth, nothing wrong with the Adire PR15's at all, but I think almost everybody here would agree with me when I say that when you get above 2 pr's it better to go with larger PR's like the 18" Stryke's. Much cheaper too!

Perhaps so, but when I already have 4 of the Adire PR15x radiators sitting in my closet that I got for $50 each, I'd tend to think that using what I have is a better idea than spending more money.

Seth

 

[John E Janowitz]

Anthony, this is a standard overhung design, but has a very long coil and short gap. As a result there is a good amount of flat area at the center of the BL curve. It is basically a scaled down version of the new HE15 or UE15 motor that dumaxed at 31mm. You can see the DUMAX report for this driver here:
http://www.stryke.com/UE15DUMAX.doc
The curve will look very similar. What you really need to look at is the BLUE measured data, and not the pink curve fit. If you look at the pink curve, you see that it is more peaky like a standard overhung woofer. The BLUE data is measured from the actual woofer though and is more accurate. This driver is mechanically a little off center, so the curve is shifted slightly to the to the right. You can see that to about 20mm to the right, and 25mm to the left, the BL drops very little, to about 22.5 Tm from it's peak of 25.25Tm at the center. In the properly centered version it will have 22.5mm each direction and BL will still be at 90%. The bumpyness in the BL curve is due to some problems that DUMAX has in their methods with measuring very high excursion woofers.
In any case, scaling this down to the AV12 and AV15, we should see that out to about 20mm we'll still be at 90% of the peak BL value. Then from 20mm to 25mm it will drop to 70%, thus giving 25mm of Xmag.
Pictures will be up tonight. The sample has the 4 spoke Venezuela basket that will be replaced by the 12 spoke MTX for the production version. I'll hopefully have a pic of the raw 12 spoke basket to put up also.
John

 

[Kyle Richardson]

Very true Seth. If you got em might as well use em and at $50ea you are sitting good

 

[ChristopherW]

John,

what would be the best amount of power to send to the AV12 in the PR alignment? I was thinking about your plate amp that puts out 350 watts.

 

[Jack Gilvey]

At this rate, we'll be up to about 30mm each way before the pre-order ends. Good work!

 

[Anthony_Gomez]

Pretty soon the 15" drivers will need a pair of 24" PRs

 

[John E Janowitz]

Well, we're done at about 25mm Xmax. Can't do anymore. sorry to disappoint everyone, but 25mm is all you get.
Originally the design called for a .5" gap plate and 2" long coil. This gave 19mm overhang and when we add 15% which is on average what we should get from a DUMAX or Klippel number we had 22mm. Then Thilo informed me the coil was actually 2.1" long. That gives an extra 1.3mm at each end, 23.3mm. Now Thilo told me that the gap plate was .375", and not .5". That gives 22mm of overhang, and DUMAX of Klippel should verify 25mm at 70% of the peak BL value.
We now have 2.5L Vd for the 12" and 4L for the 15". For comparisons to see how these compare to other well known drivers now, check out the website.
Pics are coming in a few hours.
John

 

[Anthony_Gomez]

Got one for you John (or anyone else).
Lets say that money isn't the issue.
Lets assume a Linkwitz transformed or EQed sealed enclosure (that is all I run ) and enough power to reach x-max.
Brahma-12 or the AV-12
..and why. (Dan, feel free to chime in here too )
Just trying to get a feel for where this driver stands.

 

[Anthony_Gomez]

Also, do the AV drivers used a cupped spider? ..oh ...and how did you get around any problems with potential tinsel lead slap

 

[Rick Chwiendacz]

I talked to John last night - he said that the AV12/15, like all TC drivers, use the spiders with the tinsel leads woven into them, like the MASS 2012, et al. If they're the same as the ones in the MASS, they follow more of a linear (parabolic kms curve) law than a true progresive spider (which would be higher order - relatively flat near center, and dropping fast once you hit its limits.)

While I know there are dual spiders with the tinsel leads in them, whether they're linear, progressive, or in between will have to be answered by John or Kyle.

 

[John E Janowitz]

Well, I'm sure my answer will be quite different than what most expected, but here goes....

The AV12 will have a lower F3 point in the same enclosure size as the Brahma 12. Depending on your enclosure sizes, either the Brahma or AV can have an advantage in terms of Qtc. If you're going to use an LT, or EQ, IMO you still want to start with the lowest Qtc. In a small enclosure, the Brahma has an advantage of having a lower Qtc. In 1cubic foot sealed, the Brahma has a Qtc of .665 and the AV12 Qtc of .71. In a 3 cubic foot enclosure the AV12 has a lower Qtc, .506, compared to .528. That is because of the lower overall Qts of the woofer. You can't ever get a Qtc below the Qts of the woofer. In any case, the Qtc differences are pretty minimal in either case. I don't think either is leading to any huge advantage.

The AV12 is a little more efficient. It will take less power to drive it to the same levels as the Brahma. The 3" Coil in the Brahma will allow for more overall power handling. This is where the advanage will go to the Brahma in this case.

As I said, the AV12 isn't designed to be the end all of DIY woofers. But then again you can get a pair for the price of one Brahma 12. Then the power handling edge easily goes to the pair of AV12.

Now if you compared a Brahma 15 to the HE15, then I'd have a different answer....

 

[John E Janowitz]

The drivers do have the lead wires woven into the spiders as stated by Rick. Spiders used are an 8" standard spider. They are not cupped at all. They are a flat, linear spider. I'm not a fan of progressive spiders. You run into other issues with them.

John

 

[Anthony_Gomez]

Thanks for the feedback

... the end all of DIY woofers

I WANT THAT ONE!

 

[Magnus Lindqvist]

Ok, just saw that the pictures are up at http://www.stryke.com/AVseries.html
John, will the production woofers have that logo?
//Magnus

 

[Jack Gilvey]

Hey, Rick...how've you been?

John, will the production woofers have that logo?

If so, does it come off? Looks cool otherwise.

 

[Anthony_Gomez]

as long as the cone isn't coated, it should come off with acetone with no problem.

Also, it looks like the logo was added with adobe rather than an actual logo...could be wrong though

 

[John E Janowitz]

Hello, tried to post this last night, but the forum was down for a little while. This should answer a few of the questions...
For those interested, pictures of the prototype driver are now up on the page. The prototype used a standard 4 spoke venezuela basket and a 1.75" deep magnet stack. The production verison uses the 12 spoke MTX style basket and a 2" deep magnet stack for more clearance. Also the logo on the dustcap was overlayed. It is planned to have the logo on the production drivers. If anyone who plans to order a woofer really does not care for the logo to be on their driver, let me know and I can get you one without it.
http://www.stryke.com/AVseries.html
John

 

[Anthony_Gomez]

John, the logo may be an issue for atleast 1/2 of the people. While the logo looks pretty cool for car audio (I wouldn't mind there), it sticks out like a sore thumb with the SAF for front firing. Dowfiring shouldn't really matter though Maybe itwould be more SAF friendly if the green part was not there..just have the outline.

 

[Rick Chwiendacz]

Whew - I'm 100% for no logo.
I'll be ordering mine without it.
For what it's worth - logos are fine on the back plate, on a magnet boot, or anywhere rear of the mounting flange (along the side of the basket would be fine if it's the venezuela style basket, for example. However, I've always hated logos on the dustcaps with a passion - it's actually prevented me from ordering a couple of drivers whereas if there was no logo, I'd have definitely picked them up.
Jack - I've been good, just really busy. Working almost full time and going to university full time really takes a lot out of a person (but I'm managing.)
I'm busily finishing a ~1kW subwoofer amp I'm building - once I get my AV15 + PRs, that's what I'll use to power it.
John - a couple more questions - how will the T/S params be affected by the higher magnet stack, the thinner top plate, and/or the different VC?
I know the T/S params have been static for a while, and have been the same since you quoted a .5" top plate - I'm just wondering which prototype they were measured on. If they weren't measured at all and were simulated based on the .375" top plate and 2.1" VC with the 2" magnet stack, all the better, though.