Simplified MT121 Plans
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=16270
Printed Date: 27 March 2026 at 4:06am
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: Simplified MT121 Plans
Posted By: levyte357
Subject: Simplified MT121 Plans
Date Posted: 16 April 2008 at 10:44pm
For those of us who weren't aware they were here.
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Three-Bee wrote:
Replies:
Posted By: Jake_Fielder
Date Posted: 16 April 2008 at 11:20pm
| Well done lev, it took me a while to find that plan when i was looking for it the other day actually. |
Posted By: Jake_Fielder
Date Posted: 21 April 2008 at 12:11pm
| Where did it go three-bee? |
Posted By: levyte357
Date Posted: 28 April 2008 at 1:12pm
|
Next question.
Can someone put up hornresp data for this?
Plans say it will go upto 1.6khz, but I'm sure its starts falling off sharply at approx 900hz.
My initial guestimations,
Horn length=47.8cm, Vrc = approx 11 litres, S1=360 sqcm, S2=1911cm2.
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Mark James
Date Posted: 28 April 2008 at 1:45pm
|
horn response wont model well after about 400hz iirc. 800hz seems to be the usual crossover point according to users. maybey the mods would make it play heigher??? I doubt it that much though to be honest.
------------- insert silly sentence here |
Posted By: levyte357
Date Posted: 28 April 2008 at 2:25pm
OK.. Just what I was thinking...
Gonna be a bit cheeky here
 , and ask peeps to estimate what size chamber, throat, horn length would be needed for 15" straight horn to fit below MT121 section in same cab? The 15" section would ideally handle 90-160. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Mark James
Date Posted: 28 April 2008 at 2:46pm
|
could maybey extend the selenium horns from the pas series??? they only do 120hz though...
------------- insert silly sentence here |
Posted By: levyte357
Date Posted: 28 April 2008 at 2:54pm
No pulling the wool over your eyes mate, thats exactly what and why I'm asking!!!!
The Selenium plan alledges 120-300hz, I guess it would require larger chamber/throat and longer horn to drop top 80hz. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Mark James
Date Posted: 28 April 2008 at 3:32pm
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I cant see why what your asking cant be done, might end up a bit bigger than youd have hoped for but I cant see any reason it couldnt be done lol. markk ------------- insert silly sentence here |
Posted By: Heathrow_B_line
Date Posted: 28 April 2008 at 6:50pm
|
why not start from scratch?
you have moved away from the original design anyway ------------- Produce a killer sound. Take no prisoners. |
Posted By: levyte357
Date Posted: 28 April 2008 at 7:18pm
Yes, but I guess it will stil be compromise on the 15" section; 25cm deep rear chamber + 60cm horn, and we are already talking cab depth over 80cm. If I knew exactly how to sim the Selenium 15+12 trap, it would be much easier design from there. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: TDA-Audio
Date Posted: 28 April 2008 at 9:13pm
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\\\\\\\The 15" section would ideally handle 90-160.\\\\\\\ yez (60-80 -- 140-160) \\\\Selenium 15\\\\\\ no - not work 60-80 hz... smoll mouth. and short horn... hd-15 may be... ------------- horns plans http://photofile.ru/users/tda-audio/ |
Posted By: boycey
Date Posted: 30 April 2008 at 12:02pm
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the dispersion quoted is identical to the original plan, has that been tested? (scientifically or otherwise?) i was under the impression that this is what will change with the simplified plan.
------------- the only thing more dangerous than a person who doesn't give a f**k is a person who gives a sh*t. |
Posted By: levyte357
Date Posted: 30 April 2008 at 12:30pm
|
Personally, I think easiest scenario is cab that comprises the following
2" Driver 900 -> 10Khz
MT121 160->900hz
1/2 USB 80->160Hz
Unfortunately, will be square cab due to unmodified USB section, similiar to following,
 Will need bullets/supertweeters to get that 12k-20khz sizzle, or very expensive Beyma 1.4" 755 series.
Anyone fancy drawing this up? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: josh
Date Posted: 30 April 2008 at 3:06pm
| i was thinking about this lev and i think with a bit of thought it could easily be made trapezoidal. however im not going to bother wiht it, i prefer the idea of the midtop and the mickbins being seperate, them being together will probably result in a lot of wasted space too. |
Posted By: Tekasis
Date Posted: 25 June 2008 at 12:00am
Any update on this idea ?
------------- **Heavy Weight-Line** A home without books is like a body with no soul. |
Posted By: mylesound
Date Posted: 25 June 2008 at 2:05am
|
Im also intrested in this 3 way.
I was planning on buying DDS 12"&2" fiberglass mold horn and building some HD15s with longer side and rear pannels to house the 2 horns. Its almost the same thought. |
Posted By: Deadbeat
Date Posted: 25 June 2008 at 8:32am
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Hmmm... reinventing the TMS series, are we? I'll try to get drawings up by the end of the week for you guys. ------------- Away on extended leave. |
Posted By: AdiRCF
Date Posted: 25 June 2008 at 12:53pm
I'm so tired to see on this forum this cliche. " oh sh*t, we need bullets or very expensive beyma drivers " Has enyone of you tried the 2" exit driver wnd-72 from P.Audio ? I've got 4 of them and i'm verry pleased with them. they can be cut low and they go like crazy in the upper region ------------- Sughi Bughi |
Posted By: Deadbeat
Date Posted: 25 June 2008 at 1:49pm
I can get that very cheaply. But i don't. Want to know why? Because I'm of the opinion that it sounds absolutely horrible. But that's just my opinion. I always buy the BMD and SD series of comps, at a minimum. Would take a BMS (if they're in Malaysia - never seen them over here, but heard them in England), Beyma or another superior comp even if I had to import one. Besides, it is the horn + comp that counts. I could put a crap comp on an excellent horn, and it would sound decent, and i could put an expensive comp on a crappy little horn and it would sound horrible. ------------- Away on extended leave. |
Posted By: Tekasis
Date Posted: 25 June 2008 at 1:52pm
Are they new ? Can't see them on PAP website, how much are they ?
------------- **Heavy Weight-Line** A home without books is like a body with no soul. |
Posted By: Tekasis
Date Posted: 25 June 2008 at 1:59pm
It must definately be the difference in what people hear, as many on here say the BM-D series also sounds sh*t.
I keep hearing very good stuff about the Beyma CP-755Ti's, & if they're as good as they make out, the BM-D750's will have to take a back seat!
------------- **Heavy Weight-Line** A home without books is like a body with no soul. |
Posted By: AdiRCF
Date Posted: 25 June 2008 at 2:01pm
I heard only bad things about this driver. After 10 Khz it drops and it needs a bullet to take over the upper region or some serious gain with the eq. ------------- Sughi Bughi |
Posted By: Deadbeat
Date Posted: 25 June 2008 at 4:17pm
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Different ears, maybe. I don't think the WN series is available over there. Check out loudspeakersplus for the prices in USD. WN-series isn't new, I think. ------------- Away on extended leave. |
Posted By: Mark James
Date Posted: 25 June 2008 at 4:52pm
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Well, the wnd44 is available [pap have a few in stock I believe] So I am guessing the wnd72 is available. Is it any good? Might get some to go in the mx12 if so, performance above 10khz dosn't bother me much as I will be using bullets from 8khz and up anyway. ------------- insert silly sentence here |
Posted By: Tekasis
Date Posted: 03 July 2008 at 12:37pm
According to a mate of mine, these WN-D44's blow too easy & he's replaced them all with Celestions!
------------- **Heavy Weight-Line** A home without books is like a body with no soul. |
Posted By: Deadbeat
Date Posted: 03 July 2008 at 3:45pm
|
Celestion CDX-1745 are great value. Yeah, it must be different ears for the WN thing. I know some people who favour them over the SD series, but I don't like their sound at all. For budget use, I'd go with the BMD series (as I can't get the cdx at such a good price over here), but that again is personal taste (as i find is the case with most comps, anyway). ------------- Away on extended leave. |
Posted By: MarjanM
Date Posted: 03 July 2008 at 3:59pm
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I can get CDX-1745 fairly cheap but never had a chance to hear them. Can someone make a fair comparison with some other drivers that sound similar? ------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: Tekasis
Date Posted: 21 July 2008 at 7:12pm
How high do you reckon these go ?
------------- **Heavy Weight-Line** A home without books is like a body with no soul. |
Posted By: AndyWave
Date Posted: 02 August 2008 at 10:14am
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sorry, double post.....del...... Andy ------------- torturing electrons since ...... |
Posted By: AndyWave
Date Posted: 02 August 2008 at 10:17am
Exactly. I just demolished 3 sheets of luxurious birch ply. After quite hard thinking and endless calculations (1/2 year or so), I decided it's green light for better tops. Ended like this. 12PE32 in 67cm long horn with BMS 4594 in a 80x 40 waveguide. whole box measures 70 cm high, 67 wide front ,34 wide rear and 80 deep. For bigger gigs two more but with 2x12" midbass. So small setup 12+1,4, bigger 3x12"+ 1,4". With crossover 'bout 500....800Hz I can get away without phaseplugs, ok? With ported rear for 12" there will be enough smokin' midbass. Smaller setup with some bass eq lift, bigger without. Subs are 4x 34Hz tapped horns with PD LS1802 (3rd year as particle board prototypes  , promising do 'em properly next year, as allways).Crossovers 34Hz, 110Hz, 600Hz Active, 6k300 passive So can you give me some feedback.  or  , I don't mind.Andy ------------- torturing electrons since ...... |
Posted By: levyte357
Date Posted: 21 October 2008 at 7:57pm
 However, I've been a bit naughty. I've gone and bought 2x P.Audio 2380s, as I love the JBL2380, and "apparently" a lot of 2"s comps like this horn.
Problem is, how compatible is this horn with MT121? ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: MarjanM
Date Posted: 21 October 2008 at 8:56pm
|
Any pics or plans of the Tapped horns?
------------- Marjan Milosevic MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
Posted By: Deadbeat
Date Posted: 21 October 2008 at 9:36pm
Lev - the only way to do this at this point is to try and see. Each type and execution of a horn leaves it's own 'signature' in terms of colouration of the sound in a certain way. And to a lesser extent, compression driver phase plug types  Looking at some dispersion sims I've done for the MT12, dispersion isn't really an issue. ------------- Away on extended leave. |
Posted By: AndyWave
Date Posted: 28 October 2008 at 10:24pm
Sorry for delay, gotta work for some €€€ to spend...no more holiday (building) time  . What the hell, did rain allmost whole three weeks.....No pics yet, but the design is quite simple, with only one 180deg fold. Another 45deg actually, if you count the mouth. Kinda McCowan style laying on its side, firing outta corner of enclosure. Boring simple and works well enough to me I'll repeate myself so you can sim it yourself. S1=1138, S2=1236, S3=1368, S4=2700, L1=23, L2=187, L3=25. I've got somewhat similar results as DaveyT had with his approach. In a different shape of package thou. The package. H=635mm, W=535mm, L=1265mm, external. Made of 22mm partic.....I promised my mom not to swear and curse. I recently changed the drivers to 18sound 18W1300 (mainly because of Qt from 0.25 to 0.33 & Fs from 30Hz to 35Hz & Xmech from 19mm to 50mm..... ) and it really was worth it. Sensitivity- and sound wise. I may put some pics, plans and graphs here (or in speakerporn) in (near)future. Andy |
Posted By: AndyWave
Date Posted: 30 November 2008 at 8:07pm
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Here are some measurement results of the tapped horns. Single cabinet measured in 1p (floor-sidewall), mic corrected / level not calibrated etc. enviroment. 0,5m mic distance. http://www.speakerporn.com/displayimage.php?album=random&cat=10047&pos=-223 - http://www.speakerporn.com/displayimage.php?album= http://www.speakerporn.com/displayimage.php?album=30&pos=0 - 30&pos=0 http://www.speakerporn.com/displayimage.php?album=30&pos=0 - http://www.speakerporn.com/displayimage.php?album=30&pos=1 http://www.speakerporn.com/displayimage.php?album=random&cat=10047&pos=-223 - http://www.speakerporn.com/displayimage.php?album= http://www.speakerporn.com/displayimage.php?album=30&pos=0 - 30&pos=2 On another place me n my mate stored two of these under studio table for winter (and for some proper low frequency augmentation). About 110m2 room, 2P enviroment, but the studio table deck serves as huge 3m wide 0,8m high +1m horn extension. Nice to feel and listen to 25 Hz. Not silly loud of course, "only" 2*150W good old yamaha used. So nice not to worry about overexcursion. I've often heard the term nearfield monitors, what about nearfield subwoofer? Measured at listening position. http://www.speakerporn.com/displayimage.php?album=random&cat=10047&pos=-225 - http://www.speakerporn.com/displayimage.php?album=random&cat=10047&pos=-225 I try to lend a digicamera and take some decent looking pictures of my ugly particleboard prototypes .Must do power compression measurements and few gigs with these to finally judge 'em. So far I'm satisfied.  Starts to feel reasonble to build proper plywood enclosures for subs.I should consider moving this sub talk to its own topic. Andy PS. Life goes on/Mark N-R-G (overdrive 092-12) now pounding hard. 
|
Posted By: levyte357
Date Posted: 06 March 2009 at 5:21pm
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So has anyone tried this TDA Version with any 12s, to see if it will do 160hz to 1.6khz? Guess I should have done it by now really, seeing as 4x of em are sitting in my unit. ------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Sequence Empire:::..
Date Posted: 18 March 2009 at 2:19am
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Anyone??? Also would like to know this, about to start some woodwork.... |
Posted By: El Cheapo
Date Posted: 15 June 2009 at 8:34pm
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When building these, top and bottom slope in first, or sides. So compound mitre sides or top and bot if you know what I mean?
Ta
|
Posted By: levyte357
Date Posted: 05 May 2010 at 3:43pm
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Mods, this plan needs to be a sticky...
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: levyte357
Date Posted: 24 August 2010 at 5:28pm
------------- "Who am I? I'm the guy who does his job.. You must be the other guy". |
Posted By: Venny
Date Posted: 16 November 2012 at 2:49am
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Any chance of a cut list? Thanks
------------- Predominant Culture Sound System - Roots and Culture |
Posted By: hulkeh
Date Posted: 06 March 2013 at 12:19pm
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Just to clarify the horn and the baffles are 12mm and the outer casing is 15mm or should it be 18mm? |
Posted By: shaunhastie
Date Posted: 15 July 2014 at 2:02pm
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carnet see the link for this plan any 1 help me out lol |
Posted By: bee
Date Posted: 15 July 2014 at 2:36pm
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its an mt122, just with a straight horn, and only 1 x 12 section. The plan is on the home page for the mt122, just build it with out the second 12.... ------------- https://www.elements-audio.com |
Posted By: Dub Specialist Sound
Date Posted: 30 January 2017 at 9:47am
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Anyone got 4x boxs of this design for sale? thanks ------------- Musical Roots Reggae Vibration is Life! for music is sound...sound is vibration...vibration is energy... and energy begets life. Therein lies my passion!...MUSIC IS LIFE... |