Mackie Sub Tower - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

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 26th March 2007, 01:40 PM   #1
Timtom is offline Timtom  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Los Angeles
Default Mackie Sub Tower

Hi, I posted this also on the AVS forum area but wanted to kick as may cans as possible...I am interested in some feedback on creating a "tower" stand for my HR 824's that incorporates a side loaded sub. Bully Subs did what they called the "Bully Mac" http://www.bullysubs.com/sample_sys.html but I would like to keep a slender profile. I would build a 10" wide x 30" tall 16" deep box and use either a 12" or 15" driver. I could go with a 12" & a passive like the North Creek "Thunder" design http://www.northcreekmusic.com/Thunder/ThunderInfo.htm

Driver suggestions?
Use a servo design since the mackie's are also servo controlled?
Can I use separate hi power "Pro" amps or would I be better of with a plate amp?

I envision a seamless tower profile 10w x 46t x 16d

Also should I point the side drivers towards one another for gain or way from the center....80Hz down
  Reply With Quote
Old 27th March 2007, 06:34 AM   #2
Timtom is offline Timtom  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Los Angeles
Any thoughts at all?
  Reply With Quote
Old 27th March 2007, 02:27 PM   #3
taloyd is offline taloyd  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Los Angeles, CA, USA
Default side-firing

Hello,

If you don't want an excessively large cabinet to match the width of the Mackie monitors, look into subwoofers based on the Peerless XLS and passive radiator combo (like the North Creek Thunder). You might also want to look into Rythmik Audio... they're known for top-quality bass, and their prices are VERY reasonable considering the product.

Also, their is nothing servo-controlled about the Mackie's... they're a fairly straightforward two-way monitor, with a passive radiator in back, and a controlled directivity waveguide for the tweeter.

The Rythmik Audio, however, ARE servo-controlled, and that's partially responsible for the excellent performance.

Hope this helps...

-tal
  Reply With Quote
Old 27th March 2007, 10:55 PM   #4
Timtom is offline Timtom  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Los Angeles
Hmmm, They advertize as "Servo controled" and show a "Bass servo control loop" tried to a motion detector on the layout schematic...Is this not "Servo Controlled"
  Reply With Quote
Old 28th March 2007, 12:08 AM   #5
taloyd is offline taloyd  United States
diyAudio Member
 
Join Date: Apr 2004
Location: Los Angeles, CA, USA
Default servo

Hello,

Okay, dug more into it... from:

http://mixguides.com/studiomonitors/...-monitors-498/

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The print advertisements for the HR824 make much of the direct-coupled servo loop between amplifier and speaker, from which one might infer that the HR824 features a distortion-reduction accelerometer feedback system. A look at the distortion measurement curves does not confirm this hypothesis; the distortion curves show a well-behaved characteristic but still have a conventional rise in distortion with deepening bass. Direct observation (yes, we looked inside) found only a two-wire connection to the woofer, not an accelerometer scheme. So we can assume that some sort of motional feedback/negative output impedance “servo loop” is used. The ad mentions “motional parameters,” a partial confirmation of the latter assumption.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Yamaha's YST (and the Mackie design) basically (if I understand correctly, which I may not) attempt to create a transconductance (current) amplifier out of a conventional voltage amplifier. As electromagnets (speakers) function based off of current, not voltage, having a current amplifier bypasses thermal compression and other issues tied to variable impedance, but is not exactly a servo system. In fact, a transconductance amplifier is more single-ended than a voltage, as it somewhat ignores the impedance of the load and will simply dump current into it.

In either case, I would still suggest Rythmik Audio as the best match for the Mackie's or any other 2-way speaker. They build a very well engineered product, and you would get potentially superior bass reproduction compared to a conventional subwoofer, unless you go the huge Sd/Vd route (multiple 15's, huge pro-amps, EQ to compensate for room modes, etc.). Due to the servo control of the Rythmik subwoofers, the box size is not paramount to the design. A larger box will increase transducer sensitivity, and lower power compression... however power compression is corrected for by the servo, so it affords much more leeway than a conventional subwoofer. The advantage of the Peerless XLS/radiator combo is you can have a VERY small box. But it cannot compete with the Rythmik product in terms of distortion components, etc.

Hope this helps...

-Tal Allweil
  Reply With Quote
Old 28th March 2007, 06:28 AM   #6
Timtom is offline Timtom  United States
diyAudio Member
 
Join Date: Apr 2006
Location: Los Angeles
Well, servo or not they seem to do a pretty good job at sound reproduction.

I am interested in the Rythmic subs, I have read very good reviews of them. The servo feture, that only works with their amp, correct?

I have a seperate 350w/channel that I would like to use for this project but it may not work in "servo" mode. I suppose I could implement a LT circuit but I think that can only be used with a sealed cabinet.

I suppose if I want to keep from buying another amp, the Peerless/Passive combo my be the best outlet
  Reply With Quote
Old 28th March 2007, 07:31 AM   #7
Foxx510 is offline Foxx510  Australia
diyAudio Member
 
Join Date: Nov 2006
Here is another design you could adapt using the peerless woofer Link. You would need your own sub filter/crossover though, but the suggested response curve is in the article. I've heard a small sealed 12" sub, I liked it a lot.
  Reply With Quote
Old 28th March 2007, 09:34 AM   #8
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Hmmm..........

sounds like an amplifier with (active) output resistance making it
more of a current source, this then changes the driver Qts, allowing
the box alignment to be an overdamped relatively high efficiency.

The basis of Yamaha's "air bass" system as I understand it, and
not particularly difficult to design either, if you understand it.

see http://sound.westhost.com/project56.htm

and http://www.mhsoft.nl/spk_calc.asp#newqts

/sreten.
  Reply With Quote
Old 2nd May 2007, 07:26 AM   #9
diyAudio Member
 
paulspencer's Avatar
 
Join Date: Sep 2003
Location: Melbourne, Australia
Timtom,

I have the Rythmik DS12 kit and highly recommend it!

The size you mentioned looks about right for a sealed 12" Rythmik. I was interested in the Rythmik for a long time but was put off by not being able to use my existing pro amp which has kilowatts of power! I'm now moving from two 12" drivers with a monster amp and 23mm xmax to two of this kit with 18mm xmax and 370w to each driver. The design is quite clever as it uses power more effectively than many other subs, and the servo control means much greater accuracy.
  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
Backline 600-Mackie M1400i litezoner Vendor's Bazaar 2 5th October 2008 01:51 PM
Old Mackie 1202 GORILA Power Supplies 3 9th June 2007 09:36 AM
mackie for sub amp cbecker33 Subwoofers 3 10th January 2005 04:27 AM
Mackie speaker drivers djdan Multi-Way 0 30th November 2004 06:49 PM
Mackie VLZ Pro mic pre? mhelin Instruments and Amps 3 15th July 2004 11:45 PM


New To Site? Need Help?

All times are GMT. The time now is 09:22 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