Small MLTL for Mark Audio Alpair 6 Drivers - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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
Reply
 
Thread Tools Search this Thread
Old 18th February 2009, 04:47 PM   #11
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Re Collin's comments on the 6HD and Alpair 6:

The "hump" is also present in the 6HD's low-mid performance, relatively similar to the alpair 6. This HD result is from a batch we made in late 2006. I can't speak for any 6HD units that may have been produced after we parted from Jordan some months later.

I didn't have the time to test the HD's that we made in sealed boxes, but maybe the variations in the lower frequencies would be damped in smaller sealed boxes for both drivers. I'd have to test an Alpair 6 in our anechoic chamber to be sure (when time permits!)

Cheers,

Mark.
Attached Images
File Type: jpg alp6_6hd_fr.jpg (52.4 KB, 1607 views)
  Reply With Quote
Old 18th February 2009, 05:01 PM   #12
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
That would be really interesting.

Mark, can you give us some hints why you would choose 3.5 litres for the AP6 in BR ?


Patrick

PS You should really go and get some sleep.
  Reply With Quote
Old 18th February 2009, 05:01 PM   #13
Colin is offline Colin  United Kingdom
diyAudio Member
 
Join Date: Aug 2003
Hi Mark

I haven't noticed any emphasis in that region with the JXR6 but it does sound more balanced when either used close to a wall or, if free standing, used with a second unit. I assume that provides the sort of balance normally achieved with BSC. Either way, very impressive driver, ideal for unobstrusive surround use. I hope to hear the Alpair 6 sometime.
  Reply With Quote
Old 18th February 2009, 10:33 PM   #14
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Hi Patrick,
I had the idea for a neat simple desktop that could also double as a small room system if needed. Really interesting to hear what can be delivered in the way of LF from a small package. Mark (L) was impressed when he listened to the 3 litre boxes.

I've had many emails saying box software thinks the Alp 6 will play well in sizes up to 6 litres.

Essentially, my thinking is that any small drivers (cone dia. around 2" - 50-60-mm ish)with reasonable excursion, Vas above 2.5 litres, and total Q in the region of .42 to .6 usually can work well in a mini sized BR.

Cheers,

Mark

Yep -I'm tuckered, surviving on 4 hours sleep, tonnes to do!
  Reply With Quote
Old 18th February 2009, 11:24 PM   #15
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Hi Collin,
Good to hear from you ((long time).
I did much work on coils in the early days. Different former materials gave varying results across the HD's range. I applied my experiences form the energy transmission industry in dealing with the factors that apply to operational relationships between drivers and their box environments. I've carried this knowledge on into my family of drivers. I've refined the technique to help reduced the need for BSC.

Here's an interesting graph from my other work show showing a flat response using 2 drivers in series in a 9 litre BR box (No BSC).

The HD's maybe benefiting from the same flattening effect, the driver's LF gain is off-setting the pneumatic inertia inside the box.

Also, the HD's suspension are very soft damped, there's no spider so pairing then helps to spread the work load. Room gain is welcomed, again reducing the need to increase the loads on each driver.

Cheers,

Mark
Attached Images
File Type: jpg 2xchr-markaudiotest-data.jpg (58.3 KB, 1568 views)
  Reply With Quote
Old 19th February 2009, 01:19 AM   #16
_henry_ is offline _henry_  Australia
diyAudio Member
 
Join Date: Jun 2002
Location: Australia
how does this apply if Alpair 10 Bass + Alpair 5 instead?

or 2 Alpair 10 Bass + Alpair 5
  Reply With Quote
Old 3rd March 2009, 10:46 PM   #17
diyAudio Member
 
markaudio's Avatar
 
Join Date: Nov 2008
Jim sent us his plan for the MLTL using the Alpair 6 (round frame) full range driver.

He's kindly given his consent to share the design to help DIY builders.

Here's Jim's suggestion on damping the box:

"The stuffing density is 0.5 pound per cubic foot. In my prototypes I used Acousta Stuf(Trademark) damping fiber but similar material will suffice. The stuffing should extend from below the driver to the top of the box. I place a coarse metal grid or screen on top of the internal brace to prevent the stuffing from falling below the brace and tease the material as I fill the cavity. No stuffing is placed below the internal brace"

PDF attached for downloading.

Cheers,

Mark.
Attached Files
File Type: pdf alpair6mltldrawing.pdf (17.1 KB, 494 views)
  Reply With Quote
Old 2nd April 2009, 12:54 AM   #18
diyAudio Member
 
Join Date: Aug 2006
I have been playing around with the Alpair 6 in a small BR box. Box volume is 5.55L and is tuned to around 62Hz. I am also working on a MLTL similar to Jim's but slightly larger. I have Augsberger's program and came up with some dimensions independantly. The MLTL is not ready yet, but I have a prototype of the BR box going. After a few hiccups, the little boxes are really singing beautifully in the lounge room. Midrange is special, close to electrostatic quality. I have an electrostatic so this is no BS. Placed close to a wall or in a corner these are special little speakers that have midrange clarity and detail I can't recall ever hearing before in a dynamic driver. They do take a long time to run in, and there is quite a big difference in the sound as they get run in - sweeter and sweeter. Mine are not fully run in yet, but the treble has certainly got a lot sweeter from the raw new driver. Not quite up to electrostatic standard, my electrostatic is definately cleaner in the treble, but the treble would beat a lot of the domes I have wasted a lot of money on. I can't hear any trace of sibilance. All in all a lovely smooth neutral sound with great clarity and detail.

These little BR boxes have vey high WAF. SHMBO loves them. I am going to make another pair from solid timber and they will be even more acceptable to the boss. In fact she said this morning - "See, you can get good sound from little speakers, don't BS me. Those electrostatics are way TOO BIG". Groan. Married blokes beware, they are cute and work best in places women like to dump speakers.

Anyway, the Alpair 6 are definately keepers. Very nice indeed, I'm impressed. When I get the MLTL up and running and the BR in solid wood I will put up some pictures.
  Reply With Quote
Old 2nd April 2009, 03:51 AM   #19
EUVL is offline EUVL  Europe
diyAudio Member
 
Join Date: Oct 2003
Did you use Baffle Step Correction in your BR ?


Patrick
  Reply With Quote
Old 2nd April 2009, 04:09 AM   #20
diyAudio Member
 
Join Date: Aug 2006
No. I tried but did not like the result. Sounded better up against a wall or in a corner without BSC.
  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
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 07:45 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