Small MLTL for Mark Audio Alpair 6 Drivers - Page 3 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 2nd April 2009, 05:19 AM   #21
EUVL is offline EUVL  Europe
diyAudio Member
Join Date: Oct 2003
What didn't you like precisely, if I may ask ?

  Reply With Quote
Old 2nd April 2009, 05:35 AM   #22
diyAudio Member
Join Date: Aug 2006
I thought it killed the sound, for want of a better word. Any component in the signal path is always going to sound worse than nothing at all. Also when I measured FR it didn't appear to need any BSC.
  Reply With Quote
Old 9th June 2009, 05:45 AM   #23
diyAudio Member
Join Date: Nov 2006
Default Transmission Line

The CHR 70 will do -3 db at 38hz with a transmission line enclosure. It is really an impressive driver for the price. Can not wait to get my hands on an alpair 6 in a TL and see what it can do!

  Reply With Quote
Old 15th July 2009, 08:43 PM   #24
Colin is offline Colin  United Kingdom
diyAudio Member
Join Date: Aug 2003
Location: UK
I wouldn't normally consider using a different driver for a specific enclosure design but as the Alpair 6 and Jordan JXR6HD specs are so close ...

Does Jim or anyone consider the two driver close enough to use the JXR6 in this MLTL design and if so which parameters (if any) will need adjusting?

Specs on the JXR6 pair I have are:

FO Hz - 65 Hz
Qm - 1.634
Qe - 0.71
Qt - 0.495
Re ohms - 4.498
Vas - 3.051 litres
Xmax p-p - 6.00 mm
SPL 1m 1w - 85.38

These are the standard specs for the last batch made by Mark - the F0 was measured for this pair by Ted. I initially thought the JXR6 would be unsuitable a it lacks a rear spider but I think the Alpair is the same. Is this correct?
  Reply With Quote
Old 15th July 2009, 11:29 PM   #25
diyAudio Member
Join Date: Aug 2006
No, the Alpair 6 is not the same. It does have a rear spider.
  Reply With Quote
Old 16th July 2009, 01:18 AM   #26
diyAudio Moderator
planet10's Avatar
Join Date: Oct 2001
Location: Victoria, BC, NA, Sol III
Blog Entries: 5
Default Re: Transmission Line

Originally posted by mdrake74
The CHR 70 will do -3 db at 38hz with a transmission line enclosure.

IIRC this was in reference to some plots you posted elsewhere where your measuring kit was clipping (making the measures invalid)?

community sites,, ........ commercial site planet10-HiFi
p10-hifi forum here at diyA
  Reply With Quote
Old 25th March 2013, 07:07 PM   #27
diyAudio Member
Join Date: Jun 2003
Location: Tennessee
Default Use of Generation 2 Alpair 6 Drivers

I recently did a little study to determine the functionality of Alpair 6.2 drivers in my Alpair 6.1 MLTL design. My original design used the first generation metal cone Alpair 6 drivers but only second generation drivers are currently available. The second generation drivers are the Alpair 6.2P (paper cone) and 6.2MA (metal cone).

In my simulations I use Martin King’s excellent worksheets to derive performance plots of the driver within the enclosure. In the Martin King simulations you enter the T/S specifications for the specific driver you plan to use. Next you enter an enclosure model which consists of the box length and cross-sectional area, driver location, port location, port length and diameter, and stuffing density. You then vary the box parameters and iterate until you achieve acceptable results. I usually aim to have flat frequency response down to the 3 dB corner frequency. Then I check the other performance curves to verify adequate results for impedance, phase, deflection, etc.

I re-ran my simulation model with the 6.1 driver and then plugged in Thiel/Smalle parameters for the 6.2P and 6.2MA drivers. I retained the same enclosure model for all three cases so only the T/S specs were changed for each driver. All T/S specs used were the values given on the Mark Audio and Madisound websites. For the MLTL enclosure entries I used the dimensions that I gave in the first message in this thread. Now if you compare the T/S specs for the 6.1, 6.2P, and 6.2MA drivers, there are minor differences between the three drivers. The question I had was whether the different drivers would yield similar performance results.

My MLTL Alpair 6.1 design yielded a 3 dB down point (F3) at 44 Hz with a port length of 4”. When I compared the performance curves of the three drivers, the SPL response vs. frequency plots were nearly complete overlays. The 6.1 and 6.2P drivers differ only by width of the ink lines on thier plots while the 6.2MA driver seems to have a shift of less than 0.5 dB higher SPL level vs. the other two drivers.

Thus I concluded that any of these three drivers will perform the same in my MLTL box. Of course T/S specs may differ across the production of these drivers so it is always best to measure your own drivers and rerun the simulation model to ascertain the expected results. Fortunately, most of the Mark Audio drivers are built in a single manufacturing lot so differences should be very small.

Last edited by Jim Griffin; 25th March 2013 at 07:14 PM. Reason: correction
  Reply With Quote


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
Mark Audio Alpair 10 MLTL Design Jim Griffin Full Range 210 5th April 2012 01:11 AM
Jordan JX92S from EAD or Mark Audio Alpair 10? ilwooz Full Range 56 20th March 2010 01:26 AM
Mark Audio Alpair 5/CSS SDX7 DIY Chris74 Swap Meet 4 17th February 2009 02:44 PM

New To Site? Need Help?

All times are GMT. The time now is 08:29 AM.

vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2