ALPAI 12PW - Launch - specs - diyAudio
Go Back   Home > Forums > Commercial Sector > Manufacturers > Markaudio

Markaudio Designers and builders of audiophile grade drivers

Reply
 
Thread Tools Search this Thread
Old 17th August 2014, 09:26 AM   #1
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Default ALPAI 12PW - Launch - specs

Hi Guys,
Here's the information and specifications on the Alpair 12PW. I've had to vary my time on the factory floor these last few months for reasons most of you know. As a result, Evan Yu has done much of the last minute adjustments to this driver. He's done great job. Together with Matsubara san (Farther designer of the Fe series), this driver should provide those enthusiasts intent on making larger systems with allot of "big-box" potential.

The 12PW retains the Semi-Free-To-Air single suspension design. Quite a challenge to get the rear suspension to handle the load extension. I've set its limit via the arrestor @ 8.5mm (1 way). Experienced at serious (sensible) end-users should aim to max-out the excursion at around 50% of the available mechanical extension. In a 40litre to 50litre box, this driver will make some serious bass without having to break into a sweat. I spent allot of deign time on re-tuning the PW's power-train and motor sub-assembly to get it into this operational envelope. My main goal was to retain a low-mass power train tha would remain stable under the influence of a reduced damping load. The PW has a low moving mass of under 12grams. It will be easy to driver despite its reduced SPL from its Full-Range sister.

Please remember the 12PW remains a light-duty driver. Those into "head-banging", "continuous rock-un roll" or intent on ear drum damage, the 12PW is NOT the driver for you. If however, you want to go low and get a serious audiophile quality sound where you can easily tell the audible difference between a double-bass and a bass-guitar when both instruments are oscillating at <40 cycles, this IS the driver for you.

Please pay attention to the PDF's running in and power handling advisories. This driver needs care when running-in. Its rear suspension's elastic load tolerance requires the 100 hours of low volume load to gradually get all the cross-weave fibres evenly loaded. If you give the PW a some "heavy blasts" during the run-in, you'll risk over-stretching the inner sections of the spider.

Box combinations. Dr Scott L, did some basic calculations for box volumes, which come out in the 35 litre to 50 litre range. Box alignments and port/vent tuning frequencies should reach down to the low 30's Hz. Box designers, enjoy!

Cheers
Mark.
Attached Images
File Type: jpg Alp12PW-1-id.jpg (96.0 KB, 507 views)

Last edited by markaudio; 6th September 2014 at 07:16 AM.
  Reply With Quote
Old 17th August 2014, 10:20 AM   #2
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Q & Vas are moderate, so the driver wants a larger volume than many similarly sized units. 45 litres tuned to 33Hz should do a nice job, with a lightly damped alignment.
Attached Images
File Type: png A12PW 45 litre BR.png (21.8 KB, 477 views)
File Type: gif FR.gif (33.0 KB, 464 views)
File Type: gif Impedance.gif (23.9 KB, 457 views)
File Type: gif Deflection.gif (21.5 KB, 449 views)
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com

Last edited by markaudio; 17th August 2014 at 11:44 AM. Reason: updated info
  Reply With Quote
Old 17th August 2014, 09:18 PM   #3
zman01 is online now zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
Potential for plenty of interesting designs/combinations with the A12PW... wishing you all the success with your 3 new products.

Take care.

- Zia
  Reply With Quote
Old 19th August 2014, 12:06 AM   #4
nirvana is offline nirvana  Canada
diyAudio Member
 
nirvana's Avatar
 
Join Date: Oct 2007
Location: Amos , Québec
the 7P is less efficient than the 12pw....
  Reply With Quote
Old 19th August 2014, 12:18 AM   #5
frugal-phile(tm)
diyAudio Moderator
 
planet10's Avatar
 
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Quote:
Originally Posted by nirvana View Post
the 7P is less efficient than the 12pw....
Just like one wants. Woofer should be 3-6 dB more sensitive (when you XO at the BS)

4 in 100-120 litres looka good.

dave
__________________
community sites t-linespeakers.org, frugal-horn.com, frugal-phile.com ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 19th August 2014, 12:19 AM   #6
diyAudio Member
 
Bob Brines's Avatar
 
Join Date: Jan 2003
Location: Hot Spring Village AR
Once you adjust for baffle step....

Bob
__________________
Brines Acoustics Web Site
  Reply With Quote
Old 19th August 2014, 08:45 AM   #7
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
Quote:
Originally Posted by nirvana View Post
the 7P is less efficient than the 12pw....
Is it? If you look at the FR responses you'll see they're actually about the same, hovering around the 90dB region.

The 7P is evidently designed to be a paper-cone version of the Alpair 7, i.e. it's a wideband driver capable of being run solo, not a dedicated cone tweeter. No doubt Mark could have kicked sensitivity up above 90dB, but to achieve that in a unit of this size you would almost certainly have to accept a significantly shorter VC to reduce powertrain mass, very limited suspension travel & a more powerful motor, all of which would result in a much lower Q & a higher F0, significantly limiting its wider use.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com

Last edited by Scottmoose; 19th August 2014 at 09:04 AM.
  Reply With Quote
Old 19th August 2014, 12:35 PM   #8
diyAudio Member
 
Join Date: Sep 2008
Location: Bristol
Do you think we will see a variant of the paper cone colour?

The graphite/black MAOP Alpair ones in my opinion look darn sexy!
  Reply With Quote
Old 19th August 2014, 05:08 PM   #9
chrisb is offline chrisb  Canada
diyAudio Member
 
Join Date: Aug 2002
Location: victoria BC
MAOPs in dark finish? my MAOP7s are white
__________________
you don't really believe everything you think, do you?
community sites t-linespeakers.org, frugal-horn.com commercial site planet10-HiFi
  Reply With Quote
Old 19th August 2014, 06:45 PM   #10
zman01 is online now zman01  Bangladesh
diyAudio Member
 
Join Date: Feb 2011
Location: Dhaka
IIRC Mark posted some pics of graphite/black cone variants quite a while back... or is it just our imagination?

Found it:

Post #129 at Alpair 10 Gen. MAOP Prototype TW-1

Last edited by zman01; 19th August 2014 at 06:50 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
ALPAIR 7P - launch - specs markaudio Markaudio 35 27th August 2014 03:58 AM
Product launch in the UK Waly The Lounge 13 17th February 2014 04:58 PM
Logo Launch sale! jtktam Audio Poutine 2 1st August 2013 05:51 AM
cDAC+ Launch Sale xCanadianPandax Audio Poutine 0 7th April 2013 11:07 PM
Shuttle Launch Audio - DIY? ImperfectSense Everything Else 4 6th October 2011 02:55 AM


New To Site? Need Help?

All times are GMT. The time now is 09:37 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright ©1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2