Blueprint 1203 comapared to Mass 2012 (1 Viewer)

[Jack Gilvey]

Jack, what would one way xmas be?

One way Xmas? Is that when you only get gifts?

Half of 45mm, so 22.5mm Xmax(again, assuming specs are dead-on. For the sake of discussion). Multiply the 45mm p-p by 1217 cm^2 Sd, that's about 5.5 liters of linear displacement. That's about 2.6 Mass12's, and compares rather favorably with the 3.3L linear of the HE15, for $229. Total air moved, if we look at the 80mm Xmech spec, is almost 10 liters. Real tough to bottom this thing.
Here's to hoping the numbers stick.
I measured carefully this morning, and there's no way I can fit an 18" driver manifold-mounted in my IB, barely 18" of depth to work with in the first place. Ah, well. The pure SPL of a vented EBS look very alluring.
[Edited last by Jack Gilvey on August 18, 2001 at 01:15 PM]

 

[Seungsoo Hwang]

So then I guess us people waiting for DUMAX #'s gotta wait until past the pre-order date....oh well, the price difference should be worth it for verfied numbers.

 

[Julian Data]

Hmm.. I wonder if is he is willing to send all his drivers to DLC for DUMAX Testing???
As for Xmaxp-p, IIRC yuo can theoretically cut the p-p value in half to the "one-way" reading but I don't go by that for the reason that you can have more excursion via "outward" vs "inward". Take the above example:
45mm p-p
Theoretical one-way: 22.5mm
Yet, it also can be see as forward one-way: 24mm outward and 21mm inward.
I edited the values
[Edited last by Julian Data on August 18, 2001 at 10:53 PM]

 

[Jack Gilvey]

That's interesting, Julian, I thought they just doubled the Xmax spec. to give "total displacement", or peak-to-peak.
In this case, all that's reported is the peak-to-peak #.
[Edited last by Jack Gilvey on August 18, 2001 at 04:55 PM]

 

[Jack Gilvey]

Imagine this thing in 12 ft.^3 tuned to 18hz with an 8" port driven by this ? Yee-haa. Unibox gives me 116db @ 20Hz anechoic. With a little room gain, we're already above reference, and not even close to Xmax.
[Edited last by Jack Gilvey on August 18, 2001 at 05:08 PM]

 

[Seungsoo Hwang]

Yea I was thinking of replacing my DVC15 with this driver which is essntially in that box you descrbed....just a minor port replacement and cutout widening.....drool..

 

[Julian Data]

JG:
I edited the post just a bit a go. I noticed the flaw after several hours when I posted it.
You really can't IMHO, some motor designs aren't as symmetrical. There's something about at the diysubwoofers.org site.
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[Mark Hayenga]

Just some quickies:
The frame looks like the standard cast unit used by TC Sounds, Eminence, Lambda, etc. Here's a pic of my Lambda 15" PHPHN for comparison (the eighteen just tacks on two more spokes):
Link Removed).
Oh well, it's late, so there's my .02
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Mark Hayenga
www.hayenga.com
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"My standards are so high, most of them are double."

 

[Rick Chwiendacz]

Guys.. for all who haven't read it yet. Link Removed
I also remember reading, somewhere... out there... that the p-p xmax number given by Blueprint is simply (VC length - gap height)/2.
I wish. If this were the case, the REAL xmax would end up being close to 40mm one way. Long magnetic gap topologies tend to have WAY more usable xmax than simple (VC length -gap height)/2 would indicate. The BPD '03 series motors have a 32mm magnetic gap, which is one of the reasons why their xmax is so huge. According to Pat at BPD, their xmax values are derived EXACTLY the same way Dumax derives theirs. the -3dB point of the BL product.
My discussion with him was about the 1503, and this was before the 1803 was born. They share the same motor design though, so most of what is said in my e-mail will apply to the 1803. One thing to note is that while the 1203 and the 1503 make do with a single spider, the 1803 does have the dual spiders, which should help keep eveything under control at large excursions. The 2nd spider might sacrifice a few millimeters of xsus/xmech though. Even so, Pat said that the 1503 had 80mm peak-peak xmech - so the design really had excursion to burn anyway. a few mm shaved off that wouldn't be anything to worry about.
Also, just to keep things in perspective, I've yet to see ANY manufacturer other than Dayton (Parts express) actually post the Dumax result sheet for their drivers. While Adire, Stryke/Lambda, and the like may have had their drivers tested, since they don't post the raw response sheets for us, we have no way of telling if they're actually posting the correct specs (as Tom Vodhanel pointed out to Dan Wiggins in a somewhat roundabout way awhile back.) I happen to know for a fact that there is at least one manufacturer who has had their drivers dumax tested and "selectively" updated their specs with the dumax ones where it suited them. For example, the specs posted would have the Fs and xmax from the dumax test as the Fs was lower and the xmax was higher than the previous non-dumax specs, which is good for marketing, but the Qes was higher as well, which indicates a lower motor, and those specs were ignored and left as they were before. This is very bad for the end user, because without the full Dumax response sheet to look at, manufacturers can "cherry pick" specs from various measurements taken on different drivers and using different methods, and try to pass them off as indicative of the driver design as a whole - which they won't be. In the real world, the specs won't add up, and it will be the end user who suffers.
Just in case anyone feels like asking, I'm not going to tell you who does this. It may in fact be an accident on their part and not intentional, so I've talked to them and am waiting on a response - I'd rather not put them in a negative light if it was a simple misunderstanding and not malicious in any way.
So anyway, how about it Adire, Stryke, Lambda, and everybody else? If you *have* the Dumax driver report, why the heck don't you people scan it and make it available on your website for the benefit of your customers?
- Rick

 

[Rick Chwiendacz]

By the way, Mark:
Link Removed
There's your impedance graph. I love the fact that google caches everything. I wonder what kind of ungodly huge storage array they must have?
- Rick

 

[Jack Gilvey]

Thanks for the excellent thoughts, guys. Every time I start to feel I've got a handle on this stuff, someone comes along to disabuse me.
I got an e-mail from Pat last night in response to my voicing our collective interest in seeing some Dumax results. Here's part of his response (quoted with permission):
quote: Well, we haven't had but one other question regarding Dumax and our drivers. So we were putting it of until we could pull an 1803 from the product batch and not a sample. But, if this is the case (we only follow a couple of net forums) then we should get at least the 1503 out so that Dumax can at least verify the Xmax of the driver (as it seems that this is the magic number). I will talk to David and have him get in touch with DLC and get a driver out to them. Hopefully this will put some of the questions to rest.[/quote]
[Edited last by Jack Gilvey on August 19, 2001 at 06:43 AM]

 

[James W. Johnson]

Until the 31st four of them would only be $844 instead of $1000 , thats a $150 savings.
I wish I new for sure that these drivers are going to
live up to their hype.
I really came close to purchasing two of the HE15s but after purchasing the PRs needed the cost would be well
over a grand, furthermore I would have needed much more amplification.
Imagine what 4 of these things and a few thousand watts would be like!

Don't think I won't build a sub bigger than the 'Big Pig'!

 

[Jack Gilvey]

James, Pat mentioned to me that they may extend the sale because of the delays in getting the online store operational. In regards to those who are waiting on Dumax, he had this to say:

Well, we will see about extending the sale for those who are concerend. We
would like to have them at ease with their purchase. Im sure that we can
figure something out.

I'm sure if you're buying four you can "figure something out".
Of course, if the specs are right, you'd probably need just one to have pig-style SPL. 2 in the same size cab would be insane.

 

[Tom Vodhanel]

if dumax confirmation is a worry,
ask blueprint to put up a public disclaimer on the website saying you can return the driver for a full refund + all associated shipping costs if the dumax report isn't within a reasonable window of their claims.(say 10%?)
if they claim 22+ xmax...they should deliver 19.8 dummaxed or else then.
TV

 

[Julian Data]

Great idea TV!

I rather just sit and wait for other reviews from ppl.
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[Rick Chwiendacz]

Just an FYI... Blueprint has posted a message on their website (Link Removed
- Rick

 

[Jack Gilvey]

Ahh, the power of e-mail. That's very stand-up. I have to say, I'm liking this company more and more.
quote: I rather just sit and wait for other reviews from ppl. [/quote]
I was rather hoping you'd take the leap, Julian.
[Edited last by Jack Gilvey on August 20, 2001 at 10:23 PM]

 

[Julian Data]

I was rather hoping you'd take the leap, Julian.
Me?
Currently, I am unable to devote anytime to audio testing at this point in time. Heck, I still have my dual 15 PR box uncompleted.

Right now, I am concentrating on my web business.
I do have six 15" drivers sitting here though. If I have time, I might just cut some baffles for 18" drivers.
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