MT121 top end ideas?
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=18295
Printed Date: 26 March 2026 at 8:43pm
Software Version: Web Wiz Forums 12.08 - https://www.webwizforums.com
Topic: MT121 top end ideas?
Posted By: studio45
Subject: MT121 top end ideas?
Date Posted: 14 July 2008 at 10:17pm
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Hi guys, i'm building a pair of mt121. Have got the 12" horns done and am thinking about what's going above.
Has anyone actually built a cab containing the MT wooden flare, another small wooden flare for a 6 or an 8" cone, and a 1" comp on a horn? Have seen nuff discussion about this but no actual pics or plans. Would expect more pleasant sound from paper cone in say 600-5k range than prescribed solution of 2" comp crossed at 800 which i would need to use bullets or slots with to fill in 10-20k. Could then use DE250 above 6"/8" which seems to be noted as a pleasant and smooth sounding comp driver going up to 20k. Have priced up 12"/2"/bullets and 12"/8inch/DE250 and cost is very similar. It also seems likely I could mount the DE250 in the horn mouth of the 12" although I suppose I'd really want the 6/8 in there to get the whole vocal range in one place. My boxes have come out with 535x295mm space above the 12" flare, 670mm depth. I know the correct solution is probably to get some software and design summat, but I'm on a Mac and it's a battle! Could someone let me know an approximate horn length and mouth area needed for horn loading down to 500Hz, a suitable throat area, and whether a simple straight flare will be suitable for the MT121 box in terms of dispersion? Or inform me kindly that horn design doesn't work this way :) it discombobulates me somewhat.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Replies:
Posted By: colinmono
Date Posted: 16 July 2008 at 10:06am
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You may have already considered this, but if not have a look at the Limmer 042 package http://www.speakerstore.nl/index.php?l=en&pg=25 - http://www.speakerstore.nl/index.php?l=en&pg=25 6" horn and 1" horn designed for the DE250. I've got no experience with this, but I know Dom built a single Porn Horn 12" section + Limmer box and was pleased with it, so I would have thought a single MT12 + Limmer 042 could be a good combo. I think Boycey has built some Limmer 042 boxes too recently, see thread over on freespeakerplans. |
Posted By: josh
Date Posted: 16 July 2008 at 12:45pm
| the dispersion on the limmper is much wider than the porn or mt122 if i remember rightly? |
Posted By: colinmono
Date Posted: 16 July 2008 at 2:54pm
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I believe from what I've read that the dispersion for both the Porn and the MT122 are determined largely by the HF horn; the 12" section is less directional. Add to this the fact that the limmer becomes more directional as frequency increases (the 6" is at -6dB at about 45 degrees at 800Hz, the 1" is at -6dB at 45 degrees from 2kHz or so upwards) and to me, on paper, they look like they would work. I've only looked at the plots and studied the figures though, someone with first hand experience may be able to tell you more. I found Limmer polars here: http://www.loudspeakers.de/daten/limmer/lim-042i.jpg - http://www.loudspeakers.de/daten/limmer/lim-042i.jpg Porn horn polars are on the pro audio parts site. Try searching here for Dom's posts about the limmer + porn combo too, here's one to get you started: http://www.speakerplans.com/forum/forum_posts.asp?TID=2179&PN=203 - http://www.speakerplans.com/forum/forum_posts.asp?TID=2179&PN=203 |
Posted By: studio45
Date Posted: 16 July 2008 at 3:00pm
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and it's the wrong size and layout, but cheers anyway :) reckon i could cut it in half allowing me to put the 2 horns side by side rather than having the 1 above the 6?
What horn parameter/s affects dispersion? throat size and shape mostly? or does every variable have an effect? and presumably my earlier request for basic design parameters can't be met? Do I need to decide on a driver first? come on lads let's push things forward (i build my boxes with wheels on innit  )------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: ceharden
Date Posted: 16 July 2008 at 3:24pm
| Use one of Mykey's M8 or XT8 flares above the 12" then mount a 1" inside the 12" flare as you suggested before..... |
Posted By: sKs01
Date Posted: 16 July 2008 at 4:01pm
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id say a 6" or dual 6" with a phase bung and bullets atop that would sound super nice, and was thinking of that myself for the future 8 & 12 i wouldve taught would have a lot of still usable frequency band which they both covered so a 6" would be more suitable and play higher meaning no comp necessary and you can just go straight to bullets, think HBL has a rough plan of this so might be worth asking him though finding a 6" you like the look of i would've said was priority 1 ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 16 July 2008 at 7:47pm
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Sounds good sks. i'd like to use wood for the flare if possible for cost reasons rather than buying a fibreglass moulded thing. so a good six like a Ciare 6mr8 on a short flare with a phase plug will get up to 10k you reckon? don't think I've got room for two really.
If I use a plug, (which i'd have to turn on an electric drill probably) there is no need to restrict the horn throat further, right? so inside diameter of back of horn will be about six inches and inside edges are flush with cone surround? Considering a construction of bendy MDF.....if i get going on this i'll post up some comedy pictures of "prototypes" (cockups) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 16 July 2008 at 7:56pm
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all things considered that sounds like a great idea now where did deadbeat post that bit on bungs... http://www.speakerplans.com/forum/forum_posts.asp?TID=13054&PN=4, better explanation than i could give on exactly this idea... good luck and when your done ill have to acquire the plans off you 
------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 21 July 2008 at 6:28pm
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update: bendy mdf isn't bendy enough to form a 6" radius. i've just brok two sheets into little pieces. Cockfeathers! Another square flare it is then....and more bright orange reciepts in me wallet... I'm gonna start with the largest mouth/longest flare that fits in the box, and hopefully that'll be tuned too low and I can make it a bit smaller. Of course this means the phase bung's got to be more square too. New sander belts please!
So first horn length's going to be about 55cm and mouth area about 1062 cm^2. Throat area about....about too difficult for me to work out when I think about the phase plug! But the area of a 15.5cm dia (6") cone speaker is about 754.7cm^2 so i could say about half that? ie about 377cm^2? Comments from horn experts much appreciated :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 21 July 2008 at 6:39pm
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pics:
the front of the cab as it is now 
with its lid off showing where this new little horn has to fit 
side view 
BREAKING WOOD MAKES MATT ANGRY. VERY ANGRY!!!!  ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 21 July 2008 at 7:53pm
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did you ever get a chance to see how tony ASS made the flare for the mx 600 looks like it might be a good way to go about it, a square ish phase plug and flare just dowsnt seem like it will take to playing up high really sweetly http://www.freespeakerplans.com/forum/forum_posts.asp?TID=355&PN=2 scroll down a fair way and theirs a photo and description, im sure if you asked him he could go into more detail though thats for a 12" flare im sure the theory can be used in this instance ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 31 July 2008 at 6:52pm
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right i've bashed something together. Just tested it for 1st time now. I'm a happy man though it's not there yet :)
the small upper mid horn: 
Based on dimensions of Limmer 042 6" section, with dressed polyester filler compound in the corners a la MX600. Didn't even take that long. witness the ruffness 
The front of the cab as it is now. The piezo horn isn't staying, but crossed in at 7k, actually isn't bad at all. 
The full stack, including 184Sub. 
No drastic gaps in frequency response i can hear...Have yet to measure it. Driver list: (dons asbestos jumper) Sub PD184 18" Mid bass Skytronic 902.442 12" Hi mid Maplin 55w 6.5" "Shielded Bass/Mid Woofer" Tweeter Maplin wide dispersion piezo horn Yeah yeah they're not what you'd want but they're what i've got :) Amps: Sub: CAudio Pulse 650 (650w @ 4r) Mid bass/ hi mid: Crest 4000 (300w @ 8r) Tweeter: Arcam Alpha (30w @ 8r) Crossing at 120hz, 500hz and 7kHz actively with delay and EQ using mi laptop and a clever bit of software, i can achieve a fair level of crispness. That's where i'm at with it....more progress to come...firstly getting a good 1" instead of that piezo :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: colinmono
Date Posted: 31 July 2008 at 7:16pm
Looks great, that's some proper diy horn skills you've got going there  . I reckon Tony will be proud of you if he sees this!
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Posted By: sKs01
Date Posted: 31 July 2008 at 7:25pm
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looks verry nice well done boss
 i wouldve thaught you could fit that 6" horn in if you put it through 90 degreese though what the dispersion would be like i would think that would be a prime location for a 1" or a couple of bullets maybe.... or bullets either side ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 01 August 2008 at 12:26am
u mean put the 6" horn inside the 12"? With the back box on it, it wouldn't fit. With a sealed 6 it could be done. Tomorrow i'm burn testing the maplin hi mid to find out what 55 watts full range reflex means between 500 and 7k sealed box...it's got a 300watt amp on it  Also don't think it's really got the power between about 2k and 7k, but measurements will tell. Shame it pissed it down today or i'd have had it out in the street for a better listen but had to make do with 15ftx15ft workshop 
Seriously though the 902.442 is a beefy beefy driver, don't think i'm gonna be blowing that before it's far too loud. Got 8 inch magnet, 4 inch voicecoil, kapton former, vented pole. Big fecking lump of steel :) ANyone used these? As cheap replacements in DJ monitors i bet ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 04 August 2008 at 6:54pm
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I have plots...Red trace is mic, green trace is reference
With pink noise 
With music program (some old school dub): 
The measurement setup: 
That's a Behringer ECM8000 measurement mic, a metre from the cab, in a totally acoustically untreated room (workshop). Dunno how this will affect readings. But it sounds pretty good once I'd used the measurements to adjust a GEQ in the processing software to get it flatter. But then , to me, it would :) SKS, come down and have a listen. Got no indoor room here big enough, and I feel like a twat stood in the street on me own blasting rave tunes :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 04 August 2008 at 7:00pm
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sounds like a plan, though i might have to bring some of my own tunes down to compare what its like to the pezio's and tens in my room, ill be building es18's most of this week and got a gig on friday at ethiocubano should be able to find sometime to come over what area of sheffield are you in? ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: Deadbeat
Date Posted: 04 August 2008 at 7:05pm
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'sealed back' I'd throw a pair of old LA6 CBMRs over to you (Emi), but that defies the standard model on several counts. But seriously, they're cheap and effective, as good as the Alpha 8MR imo. Great stuff, those mids look the business. I like your transition from circle to square! ------------- Away on extended leave. |
Posted By: studio45
Date Posted: 06 August 2008 at 1:52am
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Yeah can't seem to find them easily,only the 8" version, but i've just ordered another 902.442 and 2x 6.5" 902.423's (skytronic don't do model names ) which are cheap as chips and do 125w rms with 90db sensetivity, now i just need something in a 1" almost as good as a de250 for less money. or more piezo's :)
Had to almost disassemble the cab to day to put in nut sleeves where i'd used woodscrews on the drivers. I'll be putting them in earlier next time :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Deadbeat
Date Posted: 06 August 2008 at 4:36am
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Celestion CDX-1745 is my standard budget 1" that still sounds good reccomendation. ------------- Away on extended leave. |
Posted By: studio45
Date Posted: 17 August 2008 at 12:49pm
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Got two of those now, but CPC sez Celestion don't make the horns for 'em any more. B+C ME10 a good substitute? ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 17 August 2008 at 12:52pm
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these? Getting them anyway...
http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=330261293496&ssPageName=STRK:MEBI:IT&ih=014 - http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&rd=1&item=330261293496&ssPageName=STRK:MEBI:IT&ih=014 ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 18 August 2008 at 8:12pm
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for the drivers that are in them they do sound verry nice, definatley anticipating next weekend those 184 bandpass subs should complete the package niceley. ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 20 August 2008 at 6:12pm
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Got 4th coat of Aldcroft on em now, they are starting to look very dangerous :) Hot damn that stuff is good, but i can't help but feel there must be a cheaper alternative (even cheaper than Bluearan's Tuff Cab). It's just a good thick waterbased acrylic, right? What else is it that makes Aldcroft so suitable for cabs?
SKS, still only got one sub going, might have to borrow a bin off someone.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 20 August 2008 at 8:57pm
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arent their some upstairs in that worksop of yours ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 21 August 2008 at 1:16am
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they've only gone back to bloody wales where they were apparently from! so er...i need to borrow yer amps as well...this is the shoe string soundsystem right here.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 21 August 2008 at 1:21am
 nice one no worries, any plans for playing out once the other subs got a driver done btw------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 21 August 2008 at 2:23am
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nothing planned yet but i'm sure i can find an excuse for noisiness. Opus birthday bashment, house party or some such...i'm not trying to do big tings with it till it's properly developed! And i need to bash together 2 more subs as well really to make it a full system. And get another 3 sub drivers and 5 more k of amps and a processor and an eq and cables and a rack. One thing at a time... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 21 August 2008 at 1:48pm
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i know how you feel on that front, for quite a while ive been trying to get a suficiency of amps i actualy like the sound of to use and cables and cases, that last being top on my list at the moment, need to work out some sort of modular racks for my heavy amps, that and get them fixed.. ive now got the number of a guy but could you PM me some details about that bloke you were talking about? ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 21 August 2008 at 9:31pm
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surely can:
mo' work, mo' pics: 
i do like a nice threatening looking stack. if it can't make you deaf, it'll just eat you instead. 
I am locally well known for extreme neatness when working....yeah? Heard the 2 tops together, in mono, for 1st time just now. Loud enough to drown out a rock band practising each side of the workshop :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 24 August 2008 at 7:33pm
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today's manouevres:
tried a throat plate with Sd/4 aperture in it. 
Made a big spike in the response at 1k. Sounded awful. Tried Sd/2: 
Sounded better, but not as good as no throat plate at all. Might have to redesign horn completely if I want to get anywhere this way. So i decided to get into phase pluggage.... 
Anyone can do it this way....you just need vice, power drill, chisel, piece of wood for tool rest, M6 bolt and tee nut to mount workpiece. Can use sandpaper/file to polish it reet smooth as well. This one was a test to see of the method worked at all. It's too small for the horn and doesn't seem to do anything. Bigger ones should be a bit easier. It's even quite easy to dish-in the back accurately, if you offer up the cone from time to time to check the shape. Have yet to hear em though.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 25 August 2008 at 5:34pm
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this could take longer than expected. Have yet to hear improvement by putting anything in front of the cone. Whatever I try, it sounds better without. Also, plywood is a bitch to machine. MDF much better. But eats chisels!
A question: When I've got the plug doing what it should do, I should be able to measure more HF response compared to the horn without the plug, right? Will this come at the expense of anything else eg sensitivity or bandwidth? So far, I've only been able to either reduce HF output, or radically reduce bandwidth and introduce big peaks. These drivers I'm using have hollow pole pieces, I could bolt the plug in thru the centre of the driver. Yes, i'm going for a very poor man's Res4...... Though I'm seriously beginning to think I've got enough bandwidth without the plug. Seems to get up to 5k quite effectively, where I want it to meet the 1". However, I'm sure more difficulties will present themselves in due course. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 25 August 2008 at 6:00pm
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if you reckon the measurements of this are pretty similar to the limmer, anyone got the measurements and fixing dimensions of the phase plug on that?, that aught to be worth a go id've thought
------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: Deadbeat
Date Posted: 25 August 2008 at 6:06pm
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for attempting phase plugs, but if you do an RTA you should be able to see whether you really need them. Not broken, don't fix, I guess. Try the second one down. The restrictor plates you tried would have made the sound worse for a variety of reasons: http://www.users.bigpond.net.au/ggoodacre/centauri/diy/plugs.html - http://www.users.bigpond.net.au/ggoodacre/centauri/diy/plugs.html ------------- Away on extended leave. |
Posted By: studio45
Date Posted: 25 August 2008 at 8:05pm
Cheers deadbeat. I persevered a bit...my phases are now plugged:
it does actually sound brighter compared to the non plugged version next to it. Its just sitting in there on an m6 presently, not properly fixed yet. work on that tomorrow i think...Still waiting for bloody 1" horns!! ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 25 August 2008 at 8:14pm
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actually, i did read that page before beginning, and i suppose am going for his type 2 design. However I didn't make the throat small enough, so i'll have to put in an extra baffle, more filler n make the back box a bit bigger. also on these drivers the suspension sits proud of the gasket meaning the cone moves out of position when mounted like that. Bit of a bugger. Might have get different cones. These are also obviously Kevlar and I really wanted paper. But they were £7.99 each :) ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 28 August 2008 at 2:30pm
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i realise i'm hijacking other people's threads so i'll return to me own :)
Deadbeat, by open cell foam, you mean the eggcrate stuff used in studios as acoustic treatment? and this I fix inside the horn vertically across the mouth, so the driver is obscured by the foam? or do i attach panels of foam to the sidewalls of the horn? Todays efforts will include modifying the cheap kevlar driver to accept a thru- mounted plug, and rounding/smoothing the horn mouth right out the the edges of the cab. Come to think of it, have seen this form on a few horns. The corners kind of naturally radius out when you follow the contour with your file/paper. Always thought it was for looks not functionality! ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Deadbeat
Date Posted: 28 August 2008 at 3:18pm
You're looking for open cell 30ppi, this is found commonly as eggcrate, though you can buy the flat stuff from markie of course. I wouldn't block the woofer with it, just line the sides, and note that it is very important to extend this all the way to the mouth (work mouth backwards), as this is one of the main parts we are trying to improve. even a ring round the mouth works. Don't expect miracles, as I have said, it may sound flat, but that's because it is (in many ways)  .When you mount the plug through the driver, don't push it as hard as blocking the pole piece lowers power handling as it gets hotter quicker, as you know. here's a lovely pic of a driver custom made for the purpose of bolting anything through: (Pearl PR2, found on t-linespeakers.org in a push-push subwoofer page)  ------------- Away on extended leave. |
Posted By: studio45
Date Posted: 28 August 2008 at 3:43pm
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lovely looking....i'm just using a large washer and lots of epoxy! and it'll just become front vented, not rear vented. bit worried about getting dust in the vc, cos obviously I've had to cut a hole in the dustcap, but it's about as sealed as it was before.
pics in a bit when i've managed to get it set in the centre, magnetic field always tries to pull it out of line while glue's going off! ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 28 August 2008 at 7:43pm
right i've gone thru another gallon of elbow grease, shocking the price of it these days.
edges smoothed, some foam I found stapled on 
driver modding, used a jig int end 
how it looks now 
It definitely sounds brighter and is appreciably louder than the unmodified version now. To my ears though, still doesn't get much past 5k. But that might just be enough :) Signalscope won't run at the same time as my DSP software without causing lots of glitches in the audio stream, so can't do proper plots (it doesn't really do good plots anyway!). Don't really know how i'm going to get around that one at the minute. Might have to borrow someone else's machine. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: sKs01
Date Posted: 28 August 2008 at 9:26pm
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ohh thats looking fancy that is, might have to pop over on saturday again if your around, though im doing a freeparty tomorow so i may well be thoughroughly knackered ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 31 August 2008 at 7:02pm
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i am the impatient speaker builder. two days of testing, and the conclusion is ".....fcuk it, it'll do!"
have built and fitted a 5k passive xover between the 6 and the 1: 
and associated switch to select wheter the 1 is running off this xover, or an external one. 6 always gets its signal thru the xover. In every test, no matter how much I boosted the signal above 5k, it just wasn't happening in the 6 horn. So that's my xover point then :) 
so then....i got my fibreglass on! 
cheap as chips this stuff. Not too difficult to work with. As with everything I've tried so far, it looks harder than it is. There wasn't enough matting in the kit, so i'll have to do more layers later. Used candle wax as a release agent. Works really well. Laying it up: 
The raw mould before finishing: 
Gonna get more fibre tomorrow, and strengthen this bad boy/add flanges, also add in bracing as suggested by the infinitely knowledgable, Tony ASS. Now how do I get the effing wax off.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 06 September 2008 at 4:31pm
Just in case no-one else knew (took me until now to find out)...you can run WinISD without Windows, on an Intel Mac.
This is running in a program called CrossOver from Codeweavers which costs 25 notes (30 day free trial vibes right now though :)). Bargain i say given the amount of free software out there that's for Windows. Now i can hit up EAW for another 30 days of SMAART ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Deadbeat
Date Posted: 06 September 2008 at 4:35pm
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Brilliant stuff. this is the true spirit of DIY I'm busy trying to get Hornresp to run on my PPC.  Messing around with darwine------------- Away on extended leave. |
Posted By: darkmatter
Date Posted: 08 September 2008 at 12:34pm
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Deadbeat wrote:Posted By: studio45
Date Posted: 09 September 2008 at 2:04am
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cheers geezers. smaart doesn't seem to work with crossover, but sigview does, and does the transfer function thang etc so i'll see how that goes
my work bench fell apart today, i think i've been over straining it. now i have to stop building cabs to fix it. gah.... ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: Autograff
Date Posted: 12 March 2009 at 3:06pm
| Did you end up getting rid of the phase plugs then matt? Didn't see and @ ethio. |
Posted By: Deadbeat
Date Posted: 12 March 2009 at 6:09pm
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If you want to try phase plugs again, I'd reccomend going bigger with the same rough shape (maybe squash it a bit), turning the throat into a ring and going from there.
------------- Away on extended leave. |
Posted By: MikeHunt79
Date Posted: 12 March 2009 at 6:25pm
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Great work! Won't the phase plug add mass to the cone if fixed to the driver, or does the cone move independently and the phase plug? ------------- I'm English, and as such I crave disappointment. I actively seek it out. |
Posted By: darkmatter
Date Posted: 12 March 2009 at 7:41pm
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The dust cap on the cone is removed and the phase plug is attached to the (stationary) magnet. So moving mass ends up smaller if anything. How did you attach the pole piece mate? Did you remove the whole dust cap or just drill through the middle? I guess just drilling a hole could lead to some odd whistling sounds. Got me thinking, you could actually use it as a good way to conduct heat away from the driver. |
Posted By: sKs01
Date Posted: 13 March 2009 at 3:12pm
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as im around and we share the same work shop the phase plugged 6" used had a small hole drilled through the center of the dust cap and a long bolt going into a T nut in the back of the phase plug. the main issue that caused the phase plug to get abandoned was that the driver initially used was a skytek and really not in any way a high efficiency mid driver.
------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: darkmatter
Date Posted: 13 March 2009 at 3:23pm
| cheers mate :) i was wondering how the bolt's fixed to the magnet actually i.e. is it glued on or did he drill into the magnet? |
Posted By: sKs01
Date Posted: 13 March 2009 at 3:27pm
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the bolt was attached on with solder actualy iirc down the (for lack of correct terminology) cooling hole all the way through and out into the phase plug, hope that helps ------------- You're a big man, but you're in bad shape. With me it's a full time job. Now behave yourself. |
Posted By: studio45
Date Posted: 13 March 2009 at 3:28pm
For true! More like a little desktop sub driver! So far its replacement, the Fane Sovereign 6, has not displayed any need for a phase plug - i can flatten its response competely with minimal EQ, and it sounds fine without in the real world. If I did it again, I think i'd go for a "phase disc" as from what I've read they are nearly as effective and obvoiusly easier to make. Just a disc of MDF of an appropriate size, with some shaping on its rear side to match the dustcap and its front edge rounded over. ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: studio45
Date Posted: 13 March 2009 at 3:29pm
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oh it was glued on. not a good solution, it broke off pretty easily. couldn't solder it on, not enough heat in me iron - would have needed a little welder and probably have demagnetised the driver in the process ------------- Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA |
Posted By: darkmatter
Date Posted: 13 March 2009 at 4:47pm
| cheers, think i'll just mount mine in the horn's throat instead then. bit risky drilling into my B&Cs unless i know im gonna be able to do a proper job! |
Posted By: MikeHunt79
Date Posted: 15 March 2009 at 1:38am
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Have you guys seen the Danley unity horn? Looks pretty good, 4 x 6" drivers and shared the horn with a 1" comp I think. I was thinking a version with 2 x 6" drivers would be good, horizontally mounted for norrower vertical dispersion... ------------- I'm English, and as such I crave disappointment. I actively seek it out. |
Posted By: Deadbeat
Date Posted: 15 March 2009 at 10:52am
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The Unity is a special type of horn. He's got a line of improved ones called Synergies. As you know, they work on 1/4 WL coupling between sources... I wouldn't suggest it for this application. Mounting the drivers the other way wouldn't do a thing really either. If you wanted to build one, start from scratch. ------------- Away on extended leave. |
Posted By: MikeHunt79
Date Posted: 15 March 2009 at 11:45pm
Was just throwing it out there.. I think you're right tho going from scratch would give better results than a copy. I wasn't going to go for a straight copy, I was going to try experimenting with similar way of using 6" drivers in the same horn as the comp. I don't have the drivers or comps yet, or any experience of AKABAK (yet), so I'm a long way off! I think I'll have to get a a feel of akabak, and see how well it works out, but I have a feeling it would be easier just to have the 6" driver and 1" comp in seperate horns. ------------- I'm English, and as such I crave disappointment. I actively seek it out. |
Posted By: Deadbeat
Date Posted: 16 March 2009 at 7:39pm
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You can do it on hornresp. The drivers couple into one source, just model as conical horn. Basically, it's all in the patent and diyaudio. If you want to design one, I'll attempt to help. ------------- Away on extended leave. |
Posted By: MikeHunt79
Date Posted: 17 March 2009 at 12:35am
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Thanks, I'll give it a go when I've next got some free tune... I've spend most of today rewiring my car, so I've been pretty busy, once it's finished and my car runs again I'll have a bash at it in HR. ------------- I'm English, and as such I crave disappointment. I actively seek it out. |