PR's for the Blueprint 1803? (1 Viewer)

[Jack Gilvey]

Playing with more sims, it seems that fitting adequate porting in even a large box to do justice to the Link Removed is going to be difficult. I've not used them, but this is the point people usually start reaching for passive radiators.
Which ones, in a group of 3 (the other sides of the box) would handle that kind of displacement? The only one I can think of is that 18" from Stryke.
I'm picturing this project as a monster SPL machine for the ht room, as not as the last word in SQ.
[Edited last by Jack Gilvey on September 06, 2001 at 08:59 PM]

 

[Brian Steeves]

I'm picturing this project as a monster SPL machine for the ht room, as not as the last word in SQ.

You aren't kidding! That thing is a monster!
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BPS Designs Home Page

 

[BryanJ]

Jack why do you care so much about bass ?, is that all you care about when watching a movie ???
Dont you allready have a few subwoofers ???
I think one sub is good for you in your small room.

 

[Jack Gilvey]

Thanks for the suggestions, Ty. Maybe I should try one of those imaginary subs.

[Edited last by Jack Gilvey on September 09, 2001 at 09:43 PM]

 

[BryanJ]

Message removed, account suspended
[Edited last by Rob Gillespie on September 10, 2001 at 07:35 AM]

 

[Geoff L]

Bigger, better, louder, faster, junkys and our fix... It's all good!
Ground beef is good ~ steaks better, Why, just cause.
Some like the boogie man.
Reasoning can sometimes be so confusing.. But I understand.
The bigger the monster, better the bite. You surely understand (why) now, right.

 

[Jack Gilvey]

Anyway, I received this info. from Pat at Blueprint regarding any PR they might be introducing:
quote: We have had parts for the our PRs on order for a few months now. We are not
holding our breath anymore. The cones are carbon fiber/nomex honeycomb
composites with rubber surrounds. They are quite impressive in their
excursion as well. We just can't get a straight answer (in dealing with
overseas) as to when we will get them. So we are not posting anything on
our sight until we get a more concrete answer.
200 liters with 3 18" PRs and 2500 grams on each should do quite nicely in
room. BUT, I hate to recommend anything until I have actually heard it
play. This is only a computer model with averaged room transfer functions.[/quote]
There goes one possibility.
[Edited last by Jack Gilvey on September 10, 2001 at 10:58 AM]

 

[Greg Monfort]

There's the Contrabass PRs:
Sp = .129 m^2 (199.95"^2)
Qmp = 3
Mms = 1300 Grams
Cms = 400 uM/N
Fp = 4.8 Hz
Xmax = 28.5mm = 2.25" peak-to-peak
GM
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Loud is beautiful, if it's clean

 

[Jack Gilvey]

Thanks, Greg, those look killer. Are they available seperate from the sub, and what do they run? I didn't find any info. on the Servo-drive page.

 

[Greg Monfort]

Part #88-1301, though I don't know the price. I imagine you'd have to order them through a SD distributor such as Link Removed
GM
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Loud is beautiful, if it's clean

 

[Geoff L]

Certainly did not mean to offend anyone. Many of us enjoy our hobby to great extreams and love the DIY thing. Very rewarding!
Was simply makeing light of it in response to anothers not so friendly post.
Good luck Jack with the possible new BP monster. It would look to be an spl giant.
Geoff

 

[Jack Gilvey]

Geoff, you certainly didn't offend me, your intent was exactly how I took it.
Greg, thanks, I e-mailed them at earlym.com for info.
[Edited last by Jack Gilvey on September 10, 2001 at 07:00 PM]

 

[Greg Monfort]

JG, pls let me know as I'm curious now too. I haven't been keeping up lately, so what's the big deal with this new 'monster SPL machine'? Sims indicate it's outgunned by the Tempest (on less power), though it doesn't need nearly as large a cab.
GM
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Loud is beautiful, if it's clean

 

[Jack Gilvey]

The one I'm referring to is the 1803, an 18". They also make the 1503, maybe this is the one to compare to the Tempest? I do find that, outside of an eq'd box (where the higher Fs of the driver wouldn't come into play, but the 45 P-P Xmax would), like a Linkwitz transform, the Tempest models better than the 1503. Certainly in an install like an IB, the Tempest is the clear winner. The Vas of the 1503 is much lower, as you noted.
I'm only going by the published specs on the 1803, but with an Sd of 1217 cm^2 and an Xmax of 45mm P-P, it's got a Vd of about 5.5 liters for $249 ($229 pre-order). This compares rather favorably with the 3.3 liters of the HE15. Supposedly, the Xmech is in the neighborhood of 80mm. The Qts is low, and the Fs is listed at 25Hz, so it needs a pretty good size ported box to flatten things down to 20Hz.
Even in 12ft.^3, an 8" port is 30" long with an Fb of 18Hz, and port speed still creeps higher than I'd like, so I figured PRs might be the way to go. That's where I stalled.
Have a gander and tell me what you think:
Link Removed
I would be interested in your thoughts on that comparison, of course.
p.s. Based on your recommendation of last February, I finally got hold of some 3/4" marine ply, which is sitting nice 'n flat in my garage.

 

[Greg Monfort]

The 1803 is the one I compared to the Tempest. 11.7ft^3/16Hz Vs 5.5ft^3/16Hz. The 1803's extra excursion is really only useful in a sealed/IB design. At $229 though, that's cheap for this much Vb reduction. And of course 18" drivers look bitchin'.
GM
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Loud is beautiful, if it's clean

 

[James W. Johnson]

Damn Jack I wish we were neighbors, we would have all sorts of fun building new subs with these Blueprint drivers!
I think I am going to stick to a basic vented design using big boxes and ports. I have never tried a PR sub before but from what I have read it seems to be a good route to go if you are limited on space. I considered sealing my 1803s but doing this takes away too much low end, I have experimented with sealed subs quite abit and have never made one that I really liked.
How about this for two 1803s with 2000watts , just add a little EQ to the low end and your all set..
Driver : Blueprint 1803
Number of drivers : 2
Box type : Vented
Box size : 20.000 ft^3
Tuning frequency : 20.00 Hz
Vent : 1 vent(s)
19.83 in length for each
10.00 x 8.00 in rectangle
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -6.25 121.87
25.00 -4.44 123.68
30.00 -3.76 124.36
35.00 -3.26 124.86
40.00 -2.82 125.30
45.00 -2.45 125.67
50.00 -2.14 125.98
55.00 -1.87 126.25
60.00 -1.65 126.47
65.00 -1.46 126.66
I have my heart set on something like this
6000 watts applied
Driver : Blueprint 1803
Number of drivers : 6
Box type : Vented
Box size : 45.000 ft^3
Tuning frequency : 22.00 Hz
Vent : 1 vent(s)
13.28 in length for each
20.00 x 10.00 in rectangle
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -8.42 129.25
25.00 -5.08 132.58
30.00 -3.67 134.00
35.00 -2.89 134.77
40.00 -2.37 135.29
45.00 -1.98 135.68
50.00 -1.68 135.98
55.00 -1.44 136.22
60.00 -1.25 136.41
65.00 -1.09 136.57

 

[Jack Gilvey]

I have my heart set on something like this
6000 watts applied
Driver : Blueprint 1803
Number of drivers : 6

Set? I think that would cause your heart to stop. If you build that, James, it's be worth a trip out there just to see it. I imagine a much shorter trip would be required to hear it.

My interest in the PR route is not so much a space issue as it is a port-length issue. My best curve came from 1 driver in 12ft.^3 tuned to 18Hz. That one looks to exceed 120db @ 20Hz with even moderate room gain, from one driver.
My problem with building such a box is moving it from my basement up two floors to the den, or even horsing it around to finish it, etc. I could never manage something like The Pig. I suppose I could go the Sonotube route, but how does such an enclosure handle those kinds of extreme pressures?
As far as sealed, the only way to use this driver would be with a Linkwitz transform. Due to the high power handling and Vd, one can achieve huge SPLs even with an Fc of 13Hz, Q = 0.577. That wouldn't be too bad from a 2' cube.

 

[Greg Monfort]

Thanks for the link! I don't understand either of ya'lls alignments as they are both underdamped, especially JJ's. Do ya'll factor in thermal compression?
GM
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Loud is beautiful, if it's clean

 

[Jack Gilvey]

I don't understand either of ya'lls alignments as they are both underdamped, especially JJ's. Do ya'll factor in thermal compression?

Nope. The only software I have that sims any non-linearity is Adire's LspCAD, and that's only for their drivers. I've really only played with it in Unibox. Honestly, I don't understand my alignments, either, I just look for a nice curve. My 12ft.^3 seems to look like something approaching an EBS, but I'm probably way off. Now, Pat's PR alignment, 200 liters with 2500g each in 3 18" PRs, seems to be an overdamped alignment.
By "underdamped", do you mean a rolloff that's less shallow than Q = .707, if we use curve-matching? What would you suggest for an optimal vented box?
I heard from Mike Early at earlym.com. Part # 88-1301 is $126 + shipping. If I'm reading the specs correctly, The Contra PR has quite a bit more Vd than the Stryke SA-PR18-2500D , but seems to hold less mass than the dual-spider Stryke. I don't know what the max is, though, I assume the Mms of 1300g is as-shipped. Which one would you prefer, and in what alignment, for the 1803?

 

[Chris Sherman]

"Imaginary subs" huh? Well you and Ty actually have a lot more in common than you would probably care to admit. You both seem to spend a lot more time talking about building subs than actually building them. Here's an idea, how about spending a little less time posting on the message boards and more time building subs and then posting some pictures. Let's see some of your handiwork.