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MT121 revisited, revised

Printed From: Speakerplans.com
Category: Plans
Forum Name: MT122
Forum Description: Discussion / Questions about the MT122
URL: https://forum.speakerplans.com/forum_posts.asp?TID=49892
Printed Date: 19 July 2019 at 2:29am
Software Version: Web Wiz Forums 12.01 - http://www.webwizforums.com


Topic: MT121 revisited, revised
Posted By: pfly
Subject: MT121 revisited, revised
Date Posted: 14 March 2011 at 2:23am
As many know, MT122 plans on the main site are bit misleading and confusing.

Also I think this type of midtop doesn't necessarily need 18mm outer shell, since that's just what it is, shell or rack where real acoustic pieces are bolted into.

To kill some time I redrew the horn, this time completely from 15mm ply. This thickness will be enough for outer panels and at the same time will make tricky horn assembly a bit easier with its larger joint surfaces. It should also theoretically dampen the horn a bit more. I also removed mitre angles of over 45 degrees. To do this, I needed to make the whole thing few cm taller. This makes back chamber slightly larger. Other alteration that may have slight acoustic difference to the original is that I also replaced speaker baffle and horn throat baffle with 15mm ply, so there is sliiiightly more volume in compression chamber.

I hope I got all important dimensions covered in these pictures. Missing information can be measured from Sketchup file. Please let me know if something importand cannot be derived from dimensions already given in pictures.

I also hope this will make it easier to build more MT's as I believe these are very very nice basic mid horns for the price, only put off by their build difficulty.

Here is a ZIP file with pictures with measurements and .SKP file for Sketchup
http://dl.dropbox.com/u/9726318/mt121/mt121_15mm.zip - http://dl.dropbox.com/u/9726318/mt121/mt121_15mm.zip






Have fun
-Mikko



Replies:
Posted By: mikey bear
Date Posted: 14 March 2011 at 2:35am
cracking work! much appreciated Clap


Posted By: Aztor
Date Posted: 14 March 2011 at 1:26pm
Thanks. The revised version is easier.

Is it possible to create a phase plug for the MT121 ? 


Posted By: t.geessounds
Date Posted: 14 March 2011 at 3:10pm
am tryin to open the file but it dont want to open???


Posted By: pfly
Date Posted: 14 March 2011 at 4:03pm
It's a ZIP file, Windows XP, Vista and 7 should be able to open them by themself, but you can also use WinZip or WinRar to open zip files.

If you mean the .skp file inside .zip, it is Google Sketchup 8 file.


Posted By: MarjanM
Date Posted: 14 March 2011 at 4:28pm
You need to have Sketchup installed to be able to open it.

-------------
Marjan Milosevic
MM-Acoustics
www.mm-acoustics.com
https://www.facebook.com/pages/MM-Acoustics/608901282527713


Posted By: graftak
Date Posted: 14 March 2011 at 4:41pm
Do you have The Hr data for this with the altered rear chamber and front chamber..

Cheers, Graftak


Posted By: pfly
Date Posted: 14 March 2011 at 4:52pm
To be honest the differences are so small that HR can't show anything relevant. Difference in back chamber size is about the same as choosing between ferrite and nd magnet.


Posted By: graftak
Date Posted: 14 March 2011 at 6:37pm
thanx for your reply, ( and i could always put a little piece of extra wood in the chamber...)
 anyway bloody nice job making the cab eazier to build.

Cheers, Graftak


Posted By: graftak
Date Posted: 15 March 2011 at 1:35pm
is there any chance you could save this as an  Sketchup 7 file.

Cant find a free version of sketchup8..

Cheers


Posted By: djeddie
Date Posted: 15 March 2011 at 1:59pm
Originally posted by graftak graftak wrote:

is there any chance you could save this as an  Sketchup 7 file.

Cant find a free version of sketchup8..

Cheers


http://sketchup.google.com/download/gsu.html - Looks free to me!

You only have to pay for the "pro" version... which is bound to be on any number of 'warez' sites in the next couple of days.


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Chas n Dave : it's like Drum and Bass but with beards.             E=mc² ±3dB


Posted By: Tibor23
Date Posted: 15 March 2011 at 2:26pm
Thanks man, greta job. this is realy usefull:D




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S.O.K.


Posted By: eltron
Date Posted: 15 March 2011 at 3:05pm
djeddie beat me to it!

you can get pretty far with the free version imo. I had a one year license of the 7 pro, ended up not using most of the "pro" features - the only useful one is dwg import/export.


Posted By: graftak
Date Posted: 17 March 2011 at 1:42pm
yes but I cant open this plan in the free version, it said I need version 8. something...

Cheers, Graftak


Posted By: eltron
Date Posted: 17 March 2011 at 6:31pm
Yes, the current (yes, free) version is 8, downloadable on the site posted above.
Also it seems like you can install 8 parallel with 7 nowadays, just checked on two different systems, mac and win xp pc.


Posted By: collision
Date Posted: 08 January 2012 at 4:35pm
what driver did you adapt this plan for? would a pd123er work well in it?

thanks




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ONE LIFE. AVE IT.


Posted By: smoore
Date Posted: 08 January 2012 at 11:10pm
Yea can anyone make a list of compatible/recommended drivers for these plans? Or similiar T/S parameters would probably be more useful. I have eminence alpha 12" drivers and was looking at building.

 Top stuff anyway!


Posted By: PuppaBB
Date Posted: 09 January 2012 at 8:56am
And PD 12MH25?



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www.facebook.com/PuppaFran www.facebook.com/CrucialRuler www.facebook.com/DUBFever


Posted By: vibez
Date Posted: 10 March 2012 at 11:31am
I have mt122's and mt121's and have tried many drivers in them but have been most happy with bms drivers, i had to alter chamber size slightly from the original design that is on this site but results were very good in my opinion. I haven't had a close look at these new dimensions but would advise anyone building mt's to check out bms available from Tony Wilkes on here.


Posted By: fat_brstd
Date Posted: 28 December 2012 at 10:47am
I would like to build some of these over summer but dont really want to have to work out how sketch up works so was wondering if anyone had a pdf of the designs and maybe a cut list so I can start working out how many sheets of ply im going to need.

-------------
Adrians Wall Sound System
Melbournes Rootical Warrior
Roots - Dub - Steppers

http://www.facebook.com/adrians.wall" rel="nofollow - facebook page


Posted By: pfly
Date Posted: 28 December 2012 at 11:33am
the .ZIP file should have all dimensions needed in JPEG format. I don't have cutlist, that you need to work out yourself.


Posted By: pfly
Date Posted: 28 December 2012 at 12:09pm
Originally posted by collision collision wrote:

what driver did you adapt this plan for? would a pd123er work well in it?

thanks

Originally posted by smoore smoore wrote:

Yea can anyone make a list of compatible/recommended drivers for these plans? Or similiar T/S parameters would probably be more useful. I have eminence alpha 12" drivers and was looking at building.

 Top stuff anyway!

Originally posted by PuppaBB PuppaBB wrote:

And PD 12MH25?


This comes a bit late apparently:

Really, differences of few cubic cm and millimetres here and there won't really make this that different to the original Rog Mogale MT122/MT121, everything said about the original applies for this redesign also, the point of my redesign was to just make it easier to build.


Posted By: UpComingSound
Date Posted: 04 January 2013 at 3:39pm
If any one can help me out, question I just purchase the B&C 12pe32 for mt121 and am using the ashley protea 4.8sp for crossover what should i set the cross over settings at ? HPF freq and LPF freq  right now I have the HPF at 150 and LPF at 2000


Posted By: LjudLahger
Date Posted: 04 January 2013 at 3:46pm
Nice work! Clap


Posted By: UpComingSound
Date Posted: 05 January 2013 at 4:35pm
If any one can help me out, question I just purchase the B&C 12pe32 for mt 121 and am using the ashley protea 4.8sp for crossover what should i set the cross over settings at ? HPF freq and LPF freq right now I have the HPF at 150 and LPF at 2000 is that a good xover setting?


Posted By: cravings
Date Posted: 05 January 2013 at 4:51pm
can't get my MT121 12" sections to go much higher than about 900hz...


Posted By: pfly
Date Posted: 06 January 2013 at 1:58pm
Slight update: I made a version with a space for horn and compression driver, the cutout I drew is for 18Sound 1,4 to 2 inch XR series horns but there is enough space for example JBL 2380 series of horns.

https://dl.dropbox.com/u/9726318/mt121/mt121_twoway.skp" rel="nofollow - https://dl.dropbox.com/u/9726318/mt121/mt121_twoway.skp






Posted By: soundchippy
Date Posted: 06 January 2013 at 2:47pm
thanks plfy! i'm going to make it my summer project to finally build and test one of these.


Posted By: scss
Date Posted: 03 April 2013 at 5:22pm
Does Anyone Know If The Fane Sov Pro 12-500 Will Fit / Work Well In This Cab?


Posted By: pfly
Date Posted: 03 April 2014 at 6:07pm
Update from other thread:

Quote
https://dl.dropboxusercontent.com/u/9726318/mt121/mt121_twoway_VK_03.skp" rel="nofollow - https://dl.dropboxusercontent.com/u/9726318/mt121/mt121_twoway_VK_03.skp

Here is our current version of MT121 with cutout for XR2064 horn and with 157mm of depth available for 12" driver. Also included is some sort of mockup of connector panel with cutouts for 4 Neutrik STX series 4 and 8 pole Speakon connectors. Even though XR2064 is made out of aluminium, we are going to also build a support panel for compression driver.



Posted By: bozhidar
Date Posted: 07 March 2016 at 6:00am
Hello! The driver I want to put inside the single MT121 (without the horn) is 155 in total depth. How can I modify the back chamber to fit it in? How much space do I need between the magnet and the backdoor? Right now there is 145 MM from the baffle to the backdoor.


Posted By: Miles
Date Posted: 19 August 2017 at 9:54am



4 mt121 bulit after the 15mm plan by forum member pfly - give thanks for providing the plan - first audio measurements and thing looking good!




Posted By: T-Bone
Date Posted: 23 August 2017 at 12:50am
The later 2 way version in 15 mm with CD top, isn't this MT121 40X25 degree dispersion? So I would need 4 per side for 160 degree splay?  I am thinking JBL 2386 2" horn with a JBL 2450 CD? 

Thanks for the input, 12PE32 is what I am going to use.





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BASS, how low can you go!


Posted By: bob
Date Posted: 30 July 2018 at 5:57pm
Hello,
can you please reupload the plan? Would be very helpful!


Posted By: Archi
Date Posted: 01 June 2019 at 8:23am
Hi all, I've been lurking here for a while and ready to build MT121 next week
Lots of pics of MT121 has been removed or gone also the zip file in previous discuss , I need more information(like flare angles) before I start it.
Could anyone send me the file? I'll thank you thousand times!



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