waaah
nofluid/fluid/cmaber/nochamber?
What are you all recommending? camber without fluid?
does the 6/8 ohm difference between the woofer and the tweeter pose a difference?
My xo will be a 6db lowpass with impendance correction for the woofer and a 12 highpass for the tweeter?
For now, i don't have feedback in the amp, but that's easily added. Does the wild impendance graph of a low Q driver in a tl mean i should probably add some feedback?
Sorry for all the Q's, but you are all being VERY helpful here! I am learning heaps!
Bas
nofluid/fluid/cmaber/nochamber?
What are you all recommending? camber without fluid?
does the 6/8 ohm difference between the woofer and the tweeter pose a difference?
My xo will be a 6db lowpass with impendance correction for the woofer and a 12 highpass for the tweeter?
For now, i don't have feedback in the amp, but that's easily added. Does the wild impendance graph of a low Q driver in a tl mean i should probably add some feedback?
Sorry for all the Q's, but you are all being VERY helpful here! I am learning heaps!
Bas
ok...
I cannot claim which of those two tweeters would be soundwise better, but if stability is matter, than 27tdfc version probably will be slightly better due to treating of impendance peak with fluid. Just compare their impendance curves.
I'm not expert for amps, but as far as I know tube amps are sensitive to impendance changes. However, I don't think that 8 to 6 ohms switch in bass to tweeter would be hard load for that amp. I have to admit that I have no experience with tube amps but this speaker shouldn't be hard load.
I cannot claim which of those two tweeters would be soundwise better, but if stability is matter, than 27tdfc version probably will be slightly better due to treating of impendance peak with fluid. Just compare their impendance curves.
I'm not expert for amps, but as far as I know tube amps are sensitive to impendance changes. However, I don't think that 8 to 6 ohms switch in bass to tweeter would be hard load for that amp. I have to admit that I have no experience with tube amps but this speaker shouldn't be hard load.
82dm/m? no problem! I have 82 dB/m speakers right now, and they are no problemo! 75 pure tube watts in my 4,5 by 3,5 meter student room mean that cones will fly around your ears before the amp runs out of juice.
A few things i want to mention:
The 2 meter TL....why?
The reference tables from martin king state 145-168 inch, which is eq to 370cm minimum. Mathcad simulations look better too...
On the mathcad subject: what am i looking for. i have a faily constant spl now and a faily smooth impulse response. The other graphs say little to me in their reference to audio quality..
Right now i have modeled a 2sd to 1 sd 145inch tl...
when i get the drivers, i want to start building the enclosures.
Bas
A few things i want to mention:
The 2 meter TL....why?
The reference tables from martin king state 145-168 inch, which is eq to 370cm minimum. Mathcad simulations look better too...
On the mathcad subject: what am i looking for. i have a faily constant spl now and a faily smooth impulse response. The other graphs say little to me in their reference to audio quality..
Right now i have modeled a 2sd to 1 sd 145inch tl...
when i get the drivers, i want to start building the enclosures.
Bas
you are probably doing something wrong because 370cm is way to long for a quarter wave tl which will cause less bass ouput than the 200cm long pipe.
Try simulating both,you'll see which one looks better. 370cm long pipe has almost 6db less output just after 100Hz. 200 cm long pipe is more less linear to 50Hz ,where it rolls off and has a -3dB point somewhere in 40Hz,-6 round 35 Hz. In a room of your size there will be enough output even for organ music. That is for sure.
250cm is the longest pipe I would do for that driver, but with 3-3 Sd
ratio.
Try simulating both,you'll see which one looks better. 370cm long pipe has almost 6db less output just after 100Hz. 200 cm long pipe is more less linear to 50Hz ,where it rolls off and has a -3dB point somewhere in 40Hz,-6 round 35 Hz. In a room of your size there will be enough output even for organ music. That is for sure.
250cm is the longest pipe I would do for that driver, but with 3-3 Sd
ratio.
Fortunately, i did simulate both.
Maybe i am interpreting things wrong (as i said in my last post)
qw theory relies on: quarter wave!
so my thoughts were: fs = 25Hz for this driver
33/25 =+/- 13 meter
13/4 = 3,25 meter
some say you can go about 5 hz higher:
11 meter/4 = 2,6 meter
Martin king works in inches. I assumed his tables were in inches...
Are those cm? 145 cm?
in my simulations. 145 inches produces waay smoother than 80inch (about the 200 cm you proposed) and are significantly up in the 20hz region.
Don't you mean 200 inch?
Maybe i am interpreting things wrong (as i said in my last post)
qw theory relies on: quarter wave!
so my thoughts were: fs = 25Hz for this driver
33/25 =+/- 13 meter
13/4 = 3,25 meter
some say you can go about 5 hz higher:
11 meter/4 = 2,6 meter
Martin king works in inches. I assumed his tables were in inches...
Are those cm? 145 cm?
in my simulations. 145 inches produces waay smoother than 80inch (about the 200 cm you proposed) and are significantly up in the 20hz region.
Don't you mean 200 inch?
Attachments
http://www.t-linespeakers.org/design/MJK-for-dummies/index.html
According to this a driver with Qts of 0.28 is fairly marginal for a MLTQWL.
Are the results really that much better than what you'd get from
a smaller reflexed box ? A quick sim indicates 30L to 50L. Its a lot
easier to make a smaller cabinet perform well than a large one.
/sreten.
According to this a driver with Qts of 0.28 is fairly marginal for a MLTQWL.
Are the results really that much better than what you'd get from
a smaller reflexed box ? A quick sim indicates 30L to 50L. Its a lot
easier to make a smaller cabinet perform well than a large one.
/sreten.
I know. But then again, penthodes are not considered audiophile, and the exotic e1148 tubes i use are rated radio applications only and are not hyped up in the audio world.
a penthode running on only 12 volt for a preamp is considered a crime
yet, my system sounds mighty good to my ears, because with educated guesses, measurement and tinkering, i succeeded in getting good performances.
I do things because they attract me. If i can make this driver sound good in a tl, I get personal satisfaction out of it.
i don't want to rely on others, but if someone could telle me what i am doing wrong here or what i should look for, i would really greatly appreciate it!
You poited to a source that is a simplification of the real data. simulated, this driver doesn't have the awfull characteristics presented in the article you pointed out
Bas
a penthode running on only 12 volt for a preamp is considered a crime
yet, my system sounds mighty good to my ears, because with educated guesses, measurement and tinkering, i succeeded in getting good performances.
I do things because they attract me. If i can make this driver sound good in a tl, I get personal satisfaction out of it.
i don't want to rely on others, but if someone could telle me what i am doing wrong here or what i should look for, i would really greatly appreciate it!
You poited to a source that is a simplification of the real data. simulated, this driver doesn't have the awfull characteristics presented in the article you pointed out
Bas
beamnet said:
No, I ment cm. Quarter wave pipe doesn't have to be set on quarter wavelength of resonant freq of driver. It is often better if pipe is tuned higher. In your case it is a must since this driver cannot be put in pipe to give 25 hz anechoeic. In short it is because of it's low q factor. Actually 80inch pipe sim is flatter, don't know whould be happy with output of the other pipe. I guess your conclusion that other one is flatter is based on those two dips in midbass region. I would be more concerned wizh 5db less output at 90 Hz. These dips are not audible with proper stuffing and offseting driver in pipe. All proper working pipes have these dips when simmed. I heard pipe with a sim simmilar to yours and guess what? it had no bass.
My reccomendation is not to make pipe longer than 250 cm.
thanks, that kinda clears things up
now ypu seem to knw what you are talking about. What's the best place for the mouth?
I've seen back, top,low at front to and near-driver variants
i like the top firing pipe because it has the least folds
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now ypu seem to knw what you are talking about. What's the best place for the mouth?
I've seen back, top,low at front to and near-driver variants
i like the top firing pipe because it has the least folds
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But i imagine the mouth being near to the driver would have it's advantages
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Anybody able to make educated guesses?
Is it?
Do the martin king sheets rely on two equal parts of the pipe?
If not, One can see the pipe as modeled by king this way:
A closed end, folded at 90 degrees
and an open end with three folds in it. two 90 degree folds and one 180 degree fold (or 2 90 degree folds, as martin king draws it in his drawings)
This maybe is a "depend how you see it bla", but that pipe martin modeled might be more complex than at first glance
than the left design i made saves one fold on the closed end and adds none to the open end!
Bas
Do the martin king sheets rely on two equal parts of the pipe?
If not, One can see the pipe as modeled by king this way:
A closed end, folded at 90 degrees
and an open end with three folds in it. two 90 degree folds and one 180 degree fold (or 2 90 degree folds, as martin king draws it in his drawings)
This maybe is a "depend how you see it bla", but that pipe martin modeled might be more complex than at first glance
than the left design i made saves one fold on the closed end and adds none to the open end!
Bas
Got the surrounds last week. Ried guing em on, but the glue that came with them had gone bad.
Ii emailed the guys at meniscus. Their reply: we'll send you another bottle, and dit it turn out ugly? we'll send some new surrounds too!!
Well, that's awesome i think. I could'nt wait, so i stuffed them into my old speakers, just to get a rough impression. Very pleased with these...
Any hints on XO design?
Bas
Ii emailed the guys at meniscus. Their reply: we'll send you another bottle, and dit it turn out ugly? we'll send some new surrounds too!!
Well, that's awesome i think. I could'nt wait, so i stuffed them into my old speakers, just to get a rough impression. Very pleased with these...
Any hints on XO design?
Bas
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