Dear DIY'ers,
Since i have now made a nice Granite speaker that does not sound nice :-((( i would like to ask some one, who ever has the time, interest and experiance, to help me out.
i have a basic design, made with the help of an online Java applet to calculate the TML length, but i am using 2 woofers.
I did ofcource calculate using the conus surface of those 2 woofers added together.
These are made by T&T in shanghai, and have a recommended crossover of 3,5 Khz. i also found tweeters from T&T and i want to combine 2 woofers, 6.5" and one tweeter in one housing.
since this costs quite some space, about 45 CM on the front side, there is no longer just one point of beginning in the TML line.
Does this cause trouble for the function of the TML, as the length of the duct is effectivly not the same for the 2 drivers.
who could help me and do the math with MLK's mathcad sheets? im a disaster with mathematics, and can't get the hang of it.
the one willing to help me will ofcource be rewarded and with what we will have to discuss... a TA2022 amp for instance....
Thanks for your time.
Arjen Helder
Since i have now made a nice Granite speaker that does not sound nice :-((( i would like to ask some one, who ever has the time, interest and experiance, to help me out.
i have a basic design, made with the help of an online Java applet to calculate the TML length, but i am using 2 woofers.
I did ofcource calculate using the conus surface of those 2 woofers added together.
These are made by T&T in shanghai, and have a recommended crossover of 3,5 Khz. i also found tweeters from T&T and i want to combine 2 woofers, 6.5" and one tweeter in one housing.
since this costs quite some space, about 45 CM on the front side, there is no longer just one point of beginning in the TML line.
Does this cause trouble for the function of the TML, as the length of the duct is effectivly not the same for the 2 drivers.
who could help me and do the math with MLK's mathcad sheets? im a disaster with mathematics, and can't get the hang of it.
the one willing to help me will ofcource be rewarded and with what we will have to discuss... a TA2022 amp for instance....
Thanks for your time.
Arjen Helder
Photo
The small one sounds great, probably due to the fact that it uses only one driver. but it could still be better, its response could be more flat.
The Big one kinda went wrong, speakers do not sound so nice, driver quality is not good enough and i made a mistake with the crossover... this one is glued shut.. noting i can do about it now
The small one sounds great, probably due to the fact that it uses only one driver. but it could still be better, its response could be more flat.
The Big one kinda went wrong, speakers do not sound so nice, driver quality is not good enough and i made a mistake with the crossover... this one is glued shut.. noting i can do about it now
Attachments
TML design
Hi Colin, this would be relativly safe, but the problem is that i want to use cheaper drivers.
ive heard these drivers play and love there sound and at about 250 RMB per one, there a real bargain. i want to use 2X 6.5" because then the cabinet is nice and slender, it looks Very sexy in that black granite !
i know calculating it is allot of work, but its the only way to do this right, and i dont wanna mess it up... Again.
Greetings,
Arjen
Hi Colin, this would be relativly safe, but the problem is that i want to use cheaper drivers.
ive heard these drivers play and love there sound and at about 250 RMB per one, there a real bargain. i want to use 2X 6.5" because then the cabinet is nice and slender, it looks Very sexy in that black granite !
i know calculating it is allot of work, but its the only way to do this right, and i dont wanna mess it up... Again.
Greetings,
Arjen
You're welcome!
They're useless IMO. Better to extrapolate from a reflex box designer's calcs for a given Fb (Fp) IMO. Set tuning to the desired TL Fp and find the cab Vb that yields a ~3 dB peak at Fp and divide the line length into it find its cross sectional area (CSA) or you can try the old DOS program on this site which is much better than the JAVA scripts I've tried: http://www.hal-pc.org/~bwhitejr/
If more than one driver is used, then double CSA for two, triple for three, etc..
GM
They're useless IMO. Better to extrapolate from a reflex box designer's calcs for a given Fb (Fp) IMO. Set tuning to the desired TL Fp and find the cab Vb that yields a ~3 dB peak at Fp and divide the line length into it find its cross sectional area (CSA) or you can try the old DOS program on this site which is much better than the JAVA scripts I've tried: http://www.hal-pc.org/~bwhitejr/
If more than one driver is used, then double CSA for two, triple for three, etc..
GM
TML Design
Hi There Pluto,
Yeah i am actually using Glass quite often and have made good results using it, but i want to step up my accuracy, fins some better tools for designing. it will alwais be trial and error, even when all the math is done, but still, per one granite housing i need about 400 USD so yeah....... too bad.
Also getting reliable data on speakers, especially on the made in China ones is hard sometimes getting any data at all is hard already.
Today i was on the phone to get some info... if i could not speak Chinese, no way i can get what i need, now im waiting for a mail from there engineers just for some standard data as Xmax and VAS and so on.
Whell see where this go's, good drivers, especially imported ones are cheaper in the states, there are good sounding made in China drivers, but it just needs some more tinkering, as they do not supply those nice housing drawings as Fostex does.
Anyway, thanks for your input, prehaps there is some around with some more math advice!
Greetings from sticky sweaty hot Shenzhen ;-)
Hi There Pluto,
Yeah i am actually using Glass quite often and have made good results using it, but i want to step up my accuracy, fins some better tools for designing. it will alwais be trial and error, even when all the math is done, but still, per one granite housing i need about 400 USD so yeah....... too bad.
Also getting reliable data on speakers, especially on the made in China ones is hard sometimes getting any data at all is hard already.
Today i was on the phone to get some info... if i could not speak Chinese, no way i can get what i need, now im waiting for a mail from there engineers just for some standard data as Xmax and VAS and so on.
Whell see where this go's, good drivers, especially imported ones are cheaper in the states, there are good sounding made in China drivers, but it just needs some more tinkering, as they do not supply those nice housing drawings as Fostex does.
Anyway, thanks for your input, prehaps there is some around with some more math advice!
Greetings from sticky sweaty hot Shenzhen ;-)
Greets!
Right, a TL, horn, reflex, MLTL are all basically vented boxes, morphing from one to another in one long continuum, so in the end it all boils down to how much efficiency gain BW you want is a function of net Vb, i.e. the greater the net Vb, the greater its acoustic efficiency and how you shape/configure it to load the driver's inherent response determines the shape of its summed response.
GM
Right, a TL, horn, reflex, MLTL are all basically vented boxes, morphing from one to another in one long continuum, so in the end it all boils down to how much efficiency gain BW you want is a function of net Vb, i.e. the greater the net Vb, the greater its acoustic efficiency and how you shape/configure it to load the driver's inherent response determines the shape of its summed response.
GM
Hi GM, wow that is utterly fascinating. Thank you -- I appreciate it.
So Arjen, back to your question, if GM's advice is not something you can follow, if you post driver specs, a guru here will surely help you. If you want to take a crack at it, I think GM is saying:
1. Determine the tuning frequency of the TL, which yields the line length (or vice versa -- same thing). (I would think you'd need measured driver params to pick the right frequency...)
2. Model a BR in a simulation tool, making the BR's box tuning == the TL tuning freq. Adjust the box volume bigger or smaller until you have a 3 db peak at the tuning frequency.
3. Take the BR's box volume and divide by the line length to find the cross sectional area, which is width x depth (and height is line length, assuming you're not folding this TL).
4. As GM said, cross sectional area is doubled for two drivers, etc.
GM, shoot me if I'm wrong. Thank you again!
So Arjen, back to your question, if GM's advice is not something you can follow, if you post driver specs, a guru here will surely help you. If you want to take a crack at it, I think GM is saying:
1. Determine the tuning frequency of the TL, which yields the line length (or vice versa -- same thing). (I would think you'd need measured driver params to pick the right frequency...)
2. Model a BR in a simulation tool, making the BR's box tuning == the TL tuning freq. Adjust the box volume bigger or smaller until you have a 3 db peak at the tuning frequency.
3. Take the BR's box volume and divide by the line length to find the cross sectional area, which is width x depth (and height is line length, assuming you're not folding this TL).
4. As GM said, cross sectional area is doubled for two drivers, etc.
GM, shoot me if I'm wrong. Thank you again!
You're welcome!
Obviously, measured specs are best, but TLs are pretty tolerant as long as they don't have too small a CSA since with stuffing you're trading box efficiency for a relatively smooth gain BW, so always err on the large side if measured specs and an accurate math routine such as MJK's CLASSIC TL alignment tables aren't used.
GM
Obviously, measured specs are best, but TLs are pretty tolerant as long as they don't have too small a CSA since with stuffing you're trading box efficiency for a relatively smooth gain BW, so always err on the large side if measured specs and an accurate math routine such as MJK's CLASSIC TL alignment tables aren't used.
GM
designing TML
Wow guys that kinda cracks it down ai!
ill defenetly try to do this, im waiting for the factory now to give me some more specifications for the speakers.
As soon as i have those ill post them just for fun, and whell see how you guy's think about the specs.
Once again, this will not be a fullrange speaker, but a 2 way with double woofer, unless the guide sound factory can reply emails or answer there phone. both seem reeaalllyy hard for them ....
ill let you know the results.
Thanks you both!
Greetings
Arjen
Wow guys that kinda cracks it down ai!
ill defenetly try to do this, im waiting for the factory now to give me some more specifications for the speakers.
As soon as i have those ill post them just for fun, and whell see how you guy's think about the specs.
Once again, this will not be a fullrange speaker, but a 2 way with double woofer, unless the guide sound factory can reply emails or answer there phone. both seem reeaalllyy hard for them ....
ill let you know the results.
Thanks you both!
Greetings
Arjen
Designing TML
Hi There Dsney
I did actually make them from Glass first but with different drivers from the same brand ( smaller sizes ) but the same methode of calculating.
Glass is my preferred material as it is cheap and available here, a pair of glass TML's 4" cost me 5 euro here, cut to size
Hi There Dsney
I did actually make them from Glass first but with different drivers from the same brand ( smaller sizes ) but the same methode of calculating.
Glass is my preferred material as it is cheap and available here, a pair of glass TML's 4" cost me 5 euro here, cut to size
TML Design
Actually they are not made of tepered glass, as it cannot be drilled or cut to size after tempering.
i have contacted a glass factory as i would like to make some small glass speakers, 3" and 4" but they said the smaller pieces
after drilling and so on cannot fit inside the temper oven, as the distance between the rollers is too high. the would simply get stuck.
Another idea would be to buy a computer controlled PMMA cutting machine for prototyping...... but thats a bit spendy.
I have also been thinking of plasic coating the glass for more safety
i think there are many way's that lead to rome, ill find one eventually
Actually they are not made of tepered glass, as it cannot be drilled or cut to size after tempering.
i have contacted a glass factory as i would like to make some small glass speakers, 3" and 4" but they said the smaller pieces
after drilling and so on cannot fit inside the temper oven, as the distance between the rollers is too high. the would simply get stuck.
Another idea would be to buy a computer controlled PMMA cutting machine for prototyping...... but thats a bit spendy.
I have also been thinking of plasic coating the glass for more safety
i think there are many way's that lead to rome, ill find one eventually
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