Page 1 of 43 12311 ... LastLast
Results 1 to 15 of 636

Thread: Project M2 DIY Thread

  1. #1
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502

    Project M2 DIY Thread

    Since the JBL Master Reference Monitor thread is so massive I'm staring a thread that I and others can document our M2 DIY process if the. Here are some links that I was able to reference. Thank you for all of your contributions that made my and others project happen.

    Schematic of the M2 - Note: C2 in the schematic shows a value of 33.3uf, this is a typo. the correct value is 3.3uf

    DSP File

    Inside the M2

    Outside the M2

    M2 Dimensions

    Horn Mounting

    Horn Mounting pt2

  2. #2
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    Here is the photo progression of my project. Cabinets were glued with Titebond 2 and Spax MFD specific screws.

    I originally started out with using 1"x2" strips of particle board for bracing. After some recommendation I moved over to using Baltic Birch to achieve a better brace matrix. The particle boards were glued and screwed so they stayed in. With the extra volume they took up I was unable to brace exactly like the M2 in the top and bottom sections.
    Name:  IMG_3719.jpg
Views: 10057
Size:  150.2 KB

    Name:  IMG_3717.jpg
Views: 9006
Size:  132.9 KB

    Next came the primer to seal the inside. It's a 2 part epoxy primer and I sprayed 2-3 coats of it on. I taped certain sections of the cabinet and bracing I could properly glue and screw baffle on.

    Name:  IMG_3723.jpg
Views: 8565
Size:  108.8 KB

    Next came the dampening material. I was unable to locate the Owens Corning stuff POS recommended locally. I then was recommended two other options. Wrap on 16550 Bulk Roll Fiberglass or get the regular pink stuff from Home Depot and make it 1". My original plan was to use the Wrap on stuff but I realized I already had a roll of the pink stuff and figured I'd better use it since I've been storing it for this occasion.

    Name:  IMG_3732.jpg
Views: 8157
Size:  176.5 KB

    I left the horn cutout process till after the baffle was installed because I wanted to be sure the horn was in the correct place.

    Name:  IMG_3741.jpg
Views: 8144
Size:  169.8 KB

  3. #3
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    Current state, I still need to drill holes for the woofer and horn. Also I was original going to paint to standard black. Since then I've run the thought of painting it some other color, any thoughts. These will be in a dedicated room so WAF is not a problem.

    Name:  IMG_3780.jpg
Views: 8358
Size:  128.7 KB

  4. #4
    Senior Member
    Join Date
    Oct 2003
    Location
    Texas
    Posts
    1,731
    I think you'll want that fiberglass to be lining all the interior surfaces except the back of the baffle - especially behind the woofer.

  5. #5
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    That is the plan. I left it out because I was going to send it to paint. Since then it's gotten to dang cold to properly prep so I will most likely put it in so I can finally hear them and be left with an unfinished cabinet for the winter.

  6. #6
    Senior Member pos's Avatar
    Join Date
    May 2007
    Location
    Paris, France
    Posts
    2,544
    Quote Originally Posted by srm51555 View Post
    As you know the schematic in this doc has a typo: C2 should read 3.3uF instead of 33.3uF.
    If you could edit your first post to make this clear that would probably be helpful.

    Here is the correct schematic, in appendix 3: https://docs.google.com/document/d/1...h.267sxg2itu1h

  7. #7
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    Quote Originally Posted by pos View Post
    As you know the schematic in this doc has a typo: C2 should read 3.3uF instead of 33.3uF.
    If you could edit your first post to make this clear that would probably be helpful.

    Here is the correct schematic, in appendix 3: https://docs.google.com/document/d/1...h.267sxg2itu1h
    Very good, post is updated. I was waiting for confirmation before I call Parts Express and try to return these out of the 45 day policy.

  8. #8
    Senior Member
    Join Date
    Dec 2007
    Location
    wirral UK
    Posts
    650
    Quote Originally Posted by srm51555 View Post
    Current state, I still need to drill holes for the woofer and horn. Also I was original going to paint to standard black. Since then I've run the thought of painting it some other color, any thoughts. These will be in a dedicated room so WAF is not a problem.

    Name:  IMG_3780.jpg
Views: 8358
Size:  128.7 KB
    If you plan to use 'standard' fibreglass you may want to generously spray it with hairspray to fix those pesky fibres.

  9. #9
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    Thanks for the tip. Who knows, I may rip this stuff out and replace it with the wrap-on stuff, it's all pending on how sealed I can get the cabinet when painting it.

  10. #10
    Senior Member Lee in Montreal's Avatar
    Join Date
    Sep 2010
    Location
    Montréal
    Posts
    2,494
    I suggest you router all corners with a straight bit, to make them flush. It will take 5 minutes per cabinet and they will look even better. ;-)

  11. #11
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    My straight bit got plenty of use with this project. I usually set the internal cabinet depth with the bracing and shave the excess off like you recommended. It really does turn a ok cabinet into a great one. I also used it on the bracing and horn hole. After making a jig of the part I needed to make a few of all I did was rough cut with a jig saw then cleaned up with it.

  12. #12
    Member Alobar's Avatar
    Join Date
    May 2014
    Location
    Alaska
    Posts
    89
    Nice work! Should be a good thread... ! I really enjoy watching the progress on these DIY cab build projects. Makes me want to try building a speaker pair myself someday. It also shows how much goes into these projects than simply building a box or something like a kitchen cabinet. Looking forward to seeing the final result!
    L200's biamped with 2216Nd1 LF, and 077's added

  13. #13
    Senior Member srm51555's Avatar
    Join Date
    May 2013
    Location
    Wisconsin
    Posts
    502
    Quote Originally Posted by Alobar View Post
    Nice work! Should be a good thread... ! I really enjoy watching the progress on these DIY cab build projects.
    Thanks. I think we all like watching the progress of members speaker or systems, at least I do. Photo's are so much easier with camera phones.

  14. #14
    Member Fitero's Avatar
    Join Date
    Oct 2015
    Location
    Pacific Northwest
    Posts
    75
    I've been following the thread with great interest, as I too would like to start building myself a pair of M2 clones.
    Other than the dour black exterior, I want to copy the original as closely as possible

    I did some calculations of the cabinet dimensions and came up with the following;

    Volume = 147.42 Litres
    Bracing Volume = +/- 7.5 Litre
    Overall Volume = 140 Litres

    I am most puzzled by the port dimensions. The parameters provided by 4313b (JBL M2 System Simulation) and Valentin are what I have been comparing.

    Judging from the pictures, the ports flare to +/- 4" from a minimum inner diameter of approximately 44.5mm to 46.5mm. (+/- 1.75")

    I don't know squat about such things, and am unaware if JBL contemplates the Bernoulli Principle while calculating Ports. It sure appears this way to me.

    Am I missing something here?

  15. #15
    Junior Member
    Join Date
    Oct 2015
    Location
    San Antonio, TX
    Posts
    19
    Marketing Propaganda fwiw:

    M2 ENCLOSURE
    Small Footprint, Extended Bass Performance, Patented Low Frequency Port Design

    Extended low frequency performance and high SPL can be the formula for unwanted resonance. The M2 enclosure is constructed of rigid 1" MDF and with the aid of JBL’s interferometer, extensively braced for rock-solid stability at the system’s full rated power. The enclosure incorporates a JBL patented Slipstream port design with internal flares that ensure low frequency efficiency while eliminating noise caused by port turbulence. Architecturally elegant, the M2 enclosure occupies a relatively small footprint, and can be transported to various working environments.

    http://www.jblpro.com/www/jbl-story/...t#.Vmixz7-TVx4

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. JBL LN3 Project, *Official Thread
    By Nightbrace in forum Lansing Product DIY Forum
    Replies: 58
    Last Post: 07-13-2016, 03:08 PM
  2. Fundraising request; donations to Lansing Heritage Project May loudspeaker project
    By mikebake in forum Lansing Product General Information
    Replies: 7
    Last Post: 04-21-2011, 12:37 PM
  3. Project May, similar privat project?
    By Flodstroem in forum Lansing Product DIY Forum
    Replies: 14
    Last Post: 02-21-2007, 02:42 PM
  4. Fundraising for Project May Loudspeaker project
    By mikebake in forum Public Forum - Announcements
    Replies: 0
    Last Post: 02-10-2004, 07:15 AM

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •