I know this is not the right place for this, but does anyone have an idea how the enclosures we are talking about might compare to, say, a THAM 15? I wonder if there is a cost-effective sub that might be used in a THAM 15 (or THAM 12) - just curious.
I've got WT3 - "think" but not sure that those T-S are ballpark (will test soon) - Marshall Leach used that dvc MCM in a sub-sat project A Three-Way Satellite Loudspeaker System
johngalt's 47 measured TS for MCM-12inch DVC_55-1465
Hi All,
Be aware of probably unreliable TS parameters.
http://www.diyaudio.com/forums/subwoofers/76466-mcm-55-1465-a.html#post2944659
http://www.diyaudio.com/forums/subwoofers/76466-mcm-55-1465-a.html
b🙂
Hi All,
Be aware of probably unreliable TS parameters.
http://www.diyaudio.com/forums/subwoofers/76466-mcm-55-1465-a.html#post2944659
http://www.diyaudio.com/forums/subwoofers/76466-mcm-55-1465-a.html
b🙂
That would be a fun experiment! I would still need to go over my sketch and add some details and verify that all measurements fit properly ...
Im not sure what mic you are using with the Driverack (might be good , you will have to look it up) , but i use the Dayton EMM6 with HolmImpulse (free) or sometimes TrueRTA to get my relative/comparative readings.....
I usually take my comparative measurements at very close proximity indoors (for the sake of convenience), but of course in order to avoid the influence of your room's particular acoustical quirks it is ideal to measure outdoors without any nearby boundaries (except for the ground) ........ I just never do, even when i probably should, call me lazy 😛
I have found that at very close proximity the room's influence upon your measurements are minimized, but taken to the extreme with overly intimate placement (such as mic-in-terminus) you get a sort of "proximity effect" where the bottom end of the cabinet's effective range measures a little on the optimistic side ...
So keep it apples-to-apples if you know what I mean in regards to measuring technique when doing comparisons, otherwise the results are meaningless...
Yes ... I sound like Captain Obvious, i know, but if it helps a few lurkers avoid making the same mistakes i made when i first started measuring speakers then it was worth mentioning .... .
By the way guys, CHECK THIS OUT
, this proximity effect also applies on smaller scales with midrange horns and even high frequency horns! .... For fun and demonstration purposes i will attach an overlaid response graph screenshot that i took the other day when i was doing an experiment with a cheap Piezo 1016 tweeter horn .... The red trace is the tweeter mounted in a cardboard baffle placed 1 meter away from the mic on-axis, and then the brown trace was with the mic placed right in front of the horn's mouth, no more than an inch away from the mouth ........ Of course room effects do not apply here, so it was interesting to see how the proximity effect only seemed to alter the bottom end of the device's range , everything else matched up surprisingly well ! 
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Those are good Tapped Horn cabinets and well suited to drivers like Luuker's B&C 12TBX100 which are costly , but he will get 125db out of such a combination............ Affordable alternatives ($100 or less) to use in a horn like that might be something like the Dayton PA-310 , or it even looks like the Pioneer TS-W1200 Pro might even have the right specs ( someone would have to get one and test it to to be sure) , but unfortunately even with those well chosen drivers you end up with roughly 120 decibels from a 100 liter 40hz tuned cabinet because they are limited by their excursion ratings, in other words they are physically limited not electrically ........ Integrating some sort of DCR feature into a cabinet design might help these physically limited drivers meet their full potential .....
On that note , you can put an Alpine SWE-10S4 into a 100 liter Tapped Horn tuned to 40hz with 3:1 compression ratio and get 120db out of it without going into overexcursion , and at $50 cost for that driver it is a good deal for sure! , HOWEVER I can also put two of those same drivers into a 100 liter 8th order Transflex sort of cab and get 125db output down to 40hz! now THAT is an extraordinary decibel-per-dollar deal! 😀
Hello Bjorno !
Your statement is so true! I have purchased a pair of 55-2981s and also a set of 4 55-2992s , and the specs were all far different than published .... Lower VAS , higher FS , much higher Qes/Qts all seemed to be the trend ........ I understand that this is also the case with the 55-2982s (some BFM guys bought some and tested some).....
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The favorite budget 8in sub driver by MCM 55-2421 seems to measure fairly close though - as reported somewhere on this forum. I usually look at the size of the ferrite magnet (you can't tell based on size of Nd). If it has Qts below 0.35, it better have a fat magnet. 2421 indeed has a fat magnet.
I would certainly be willing to build a THAM 12 - if I can find a driver that is priced right.
Laserpaddy ,
That driver has a VAS figure of over 300 liters, so it would likely need a large cabinet if you want it to play the deeper bass notes effectively, but if you don't mind that then it could be made to work ..... It's xmax rating is 4mm so if you wanted to be able to get it anywhere near it's power rating then you also might want to consider the DCR feature ..... I am working on a DC-TL concept that is pretty simple and straightforward .....
This winISD 7 version that some of the other guys suggested is pretty cool ... Better looking interface compared to the one i was using before .. .
Cool looking to maybe mount it under the floor between the floor joists vent into room...or not...but the main use no matter the enclosure type, size etc.. Is the LFE output . Going to start my design phase in about a week or so...a large cabinet that has MDF or plywood main box and some real nice hard wood exterior that way my wife won't freak out...if I don't do it that way its under the floor between the joists for sure.....
I had issues with winISD on windows 8 pro 64 bit- I couldn't save the new driver n the sheet without a corruption warning and then values were partially gone..
Any good cheap purchase type packages? Eminence seems easy...
Anyone got suggestions?
I had issues with winISD on windows 8 pro 64 bit- I couldn't save the new driver n the sheet without a corruption warning and then values were partially gone..
Any good cheap purchase type packages? Eminence seems easy...
Anyone got suggestions?
regarding the MCM DVC woofer (MCM Part #: 55-1465) , with a jumper between coils and twisted to terminals (not soldered) - I get hand holding the thing: Re= 3.057, fs = 26.92Hz, qes = 0.3568, qms= 3.208. qts = 0.3209 and Le = 0.8907mH - IIRC that's not real far off from what Marshall Leach measured years back.
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Laser ,
Ok then , So you are cool with a larger box and are reproducing LFE, a lower tune could be in the cards for you 🙂 You also wont really need to be concerned with extended bandwidth on the top end ...
What is your driver budget? and what sort of amp will you be using to drive it?
Freddi,
What sort of tuning are you shooting for? 35hz to 40hz like most of the designs in this discussion or something different?
something small and punchy - a LF corner a bit below 50 would probably suffice. When that MCM 12 was mounted in a Karlson 12 with its 1.3 cubic foot rear chamber vent sealed, it gave the following in-room response with the mic on the floor and 20" away. I didn't try fill in the rear chamber but that probably could give qtc ~0.7 if desired (and if that applies to BP4 types)
An externally hosted image should be here but it was not working when we last tested it.
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I have the eminence 15 beta on hand, but doesn't really need to be "the" driver. I would run a crown 1500 at least.
I was actually planning the 15beta with 2 8" mids and a horn for a center channel, and then I found this thread...
So if I were to get another driver I would go with 2 12's and the xl1500 , I have a Polk 660wi now but I am not impressed I had a dvc 10" cerwin Vega sub in a mustang in 1987 that kicked the crap out of this Polk, so my options are open cheap is good but quality is key so usually I find a happy place.
Hi Y'all,
What a week. Looks like I can't keep up w/ all the different builds being discussed here. 🙂
I just would like to point out, that the Infinity Reference 1262 W can be used as a replacement for the LAB12 in a lot of the large and low home oriented designs. (In my opinion not for PA.) It is still available at Sonic Electronix for US $61.95 ea., $110.00 for a 2 pack, free shipping (and I'm out of shelf space).
Infinity 1262W Reference Series 1200W 12" Subwoofer
Pair of Infinity Reference 1262W (REF1262W) 12" Dual 4 ohm Subs
Question for freddi: Are the T/S parameters for the MCM 55-1465 in Post #832 from a recent buy, or from a driver that has been around for a while? And, have you seen the data on the MCM 55-2962? That would be one heck of a driver for $23.69 ea., or 4 pieces @ $20.99 ea.; I even has a respectable looking spec sheet. Oh well, paper is patient.
MCM Audio Select 12'' Die Cast Woofer with Paper Cone and Cloth Surround - 175W RMS 8ohm | 55-2962 (552962) | MCM Audio Select
Regards,
What a week. Looks like I can't keep up w/ all the different builds being discussed here. 🙂
I just would like to point out, that the Infinity Reference 1262 W can be used as a replacement for the LAB12 in a lot of the large and low home oriented designs. (In my opinion not for PA.) It is still available at Sonic Electronix for US $61.95 ea., $110.00 for a 2 pack, free shipping (and I'm out of shelf space).
Infinity 1262W Reference Series 1200W 12" Subwoofer
Pair of Infinity Reference 1262W (REF1262W) 12" Dual 4 ohm Subs
Question for freddi: Are the T/S parameters for the MCM 55-1465 in Post #832 from a recent buy, or from a driver that has been around for a while? And, have you seen the data on the MCM 55-2962? That would be one heck of a driver for $23.69 ea., or 4 pieces @ $20.99 ea.; I even has a respectable looking spec sheet. Oh well, paper is patient.
MCM Audio Select 12'' Die Cast Woofer with Paper Cone and Cloth Surround - 175W RMS 8ohm | 55-2962 (552962) | MCM Audio Select
Regards,
