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Is gonna tell me what a goddam MLTL is? I ask one question and I can't get an answer?
Follow Ups:
I was curious knowing that GM was keen on them.
Martin King and Bob Brines are two folks that model/build Mass Loaded Transmission Lines. Somehow I don't think you're going to be interested unless you are gonna replace those single drivers in your TV set!
Greets!A number of folks have been right pleased with the improvement MLTLs can have on 414s, 416s, 515s, 604s, etc., over traditional BR cabs, including the factory ones, not to mention JBL and other popular brand HE drivers. Indeed, they can perform as good or better than the revered Onken without all the extra woodworking, though of course they lack its distinctive looks.
GM,I realize that there are maths and theories behind all this, but the cabinets look like just a regular BR to me. I will try to digest MK's site one day. Off-hand, would you know how different the sound of the 604 would be in a MLTL cab as oppose the the 620A cabinet?
Greets!BR assumes a ~uniform particle density, but once one dimension becomes long enough to begin supporting standing waves to further load the vent it's no longer a BR per se, but a 1/4 WL transmission line in series with a 1/2 WL resonator. Obviously, there's no sharp transition, but a morphing from one to another and the easiest way to determine if it's a MLTL is when either the vent length must be shortened to maitain a given Fb or Fb shifts lower in frequency.
I've never directly compared these two, but typically a true BR such as the 620 will require much more damping material to match the MLTL's greater acoustic damping.
Are there any MLTLs done with vintage 15" drivers where the project is documented on-line?
Greets!Hmm, can't think of one at the moment other than the designs I listed in the Altec forum thread. What are you interested in?
I can get my hands on a pair of Altec 515-16g and I was thinking of using a large Onken cabinet with EQ or series resistance similar to what kevinkr from diyaudio.com has done. What is the MLTL alternative?
Hi,I saw GM's reply to SY on the thread way down... Makes me wonder though how they time/phase aligned the Fostex(?) supertweeter mounted on the main baffle, or if alignment is critical at all if xo'd ~15k?.. Anyway, it's something to aspire to with my 414s. GM has dims dims for them posted in the archives here (thanks for the building tips GM!)
fred
Greets!You're welcome! Even with a 1st order XO, if you can hear a phase shift beyond possibly being able to discern a slight tonal difference by swapping the leads, then I imagine there's scientists that would like to 'pick your brain', so to speak.
Greets!OK, how much series R and what max cab height? The A7's 42" or ?
Series R: 9 ohms to as much as 16 ohms is what I'd intended with the Onken cabinet. I think 11 ohms was what flattened the response in the cabinet size I was looking at initially: 360 litres. Eventually I intend to build an amp with the necessary output impedance rather than waste the power in a resistor.42 inches puts the centreline of the midrange horn at 56 inches which is a little too tall for seated listening. I'd prefer them to be a little shorter, but it depends on the benefits gained from a taller cabinet.
The cabinets could be both wide and deep if additional volume is required, as the midrange horn is 30" wide and 28" long. This suits the orginal 360 liter Onken size quite well.
hey GM - do ya think AJ horn's math would correlate? - driver position can be moved to somd degree
I did a bit of language editing on the AJ program--and I hope translation confusion is minimal--I can't vouch for the math, but, if I understand it, AJ treats everything from OB, BR, to BLH from the driver's point of view...so you get the loading front and rear, and AJ will give an accurate response summing the front and back loads--this is a traditional engineering perspective. IIRC, the assumptions of AJ is that ALL T/S parameters can be known/derived and that accurate response can be predicted therefrom.
Greets!Dunno, I can't remember if folks who use it have done any off-set TLs or MLTLs with it or not. I imagine they have, but can't one at the moment.
Now take it easy on Tom, he's a colorful guy. Maybe he is having trouble with regularity. If you don't play around with single driver systems you probably don't know what they are, I know I didn't for a while until I went over to the single driver forum. You have to admit he doesn't hold back his feelings, I really like him. At least he is not a stuffy shirt.
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Took me all of 3 minutes to find this with a search of the archives.
http://db.audioasylum.com/cgi/m.mpl?forum=hug&n=116658&highlight=what+is+mltl&session=
Try it sometime.
"Is gonna tell me what a goddam MLTL is?"A new wrinkle on an old wrinkle?
A tapered quarter wave pipe with a port at the terminus. Claims you can shorted it if you stuff it with a fibrous tangle.
mass loaded transmission line?
:)
Loud is Beautiful if it's Clean!
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