Hi @ll
I have got a new idea how to calculate and build a TML. I would like to share my ideas with you.
First thought: TML = vented system
A TML is a vented construction like a Horn, TQWT, BR etc. The big difference is that the line is getting tighter.
Second thought: tuning frequency (f TML)
You find in literature that you should set the tuning frequency on the free air frequency (f s) of the driver. According to other projects from me I thing that you shouldn’t use one frequency for two different parameters.
And I have the feeling that the tuning frequency should be a bit higher than the free air frequency of the driver.
Third thought: starting section (A H) and ending section (A M)
The starting section (AH) has got to be in a certain percentage to the ending section (AM). In the past I have played a lot with 1,6181 (we call it golden cut).
Fourth thought: volume of the line (VTML)
I cases that the line gets smaller the air load on the driver will be higher. Therefore I thing that the volume has to be higher that the volume of a Bassreflex (Vbr). A have made similar notice with my way of building a backload horn.
In order of the starting -, ending area and the length we have a volume. This volume should be emotional 1.5 – 1.6 times higher than the Bassreflex. I have had 1.2 – 1.3 times higher volumes at BL-horns and here we load the horn after the chamber.
Fifth thought: the right driver
A driver for a BR should be the right driver for a TML. Qts around 0.25 – 0.4 should work fine
Starting the calculation:
First we need the optimal BR volume (VBR) and calculate it with the factor.
(-> formula 1)
Simplified we can calculate the tuning frequency (fVTML) of the driver in that volume.
(-> formula 2)
The tuning frequency of the TML length (fTML) should be between the free air frequency (fs) and the tuning frequency (fVTML) of the driver in the volume.
(-> formula 3)
We get the length with:
(-> formula 4)
When we have found out the optimal volume we can calculate the starting and ending sections. All we have to do is to convert the formula for the volume. The requirement is that the sections stand in a certain percentage.
(-> formula 5)
(-> formula 6)
(-> formula 7)
Opening section is than:
(-> formula 8)
Than I have placed the driver at 1/3 of the TML-length and simulated a drive I am playing with right now.
I have got a new idea how to calculate and build a TML. I would like to share my ideas with you.
First thought: TML = vented system
A TML is a vented construction like a Horn, TQWT, BR etc. The big difference is that the line is getting tighter.
Second thought: tuning frequency (f TML)
You find in literature that you should set the tuning frequency on the free air frequency (f s) of the driver. According to other projects from me I thing that you shouldn’t use one frequency for two different parameters.
And I have the feeling that the tuning frequency should be a bit higher than the free air frequency of the driver.
Third thought: starting section (A H) and ending section (A M)
The starting section (AH) has got to be in a certain percentage to the ending section (AM). In the past I have played a lot with 1,6181 (we call it golden cut).
Fourth thought: volume of the line (VTML)
I cases that the line gets smaller the air load on the driver will be higher. Therefore I thing that the volume has to be higher that the volume of a Bassreflex (Vbr). A have made similar notice with my way of building a backload horn.
In order of the starting -, ending area and the length we have a volume. This volume should be emotional 1.5 – 1.6 times higher than the Bassreflex. I have had 1.2 – 1.3 times higher volumes at BL-horns and here we load the horn after the chamber.
Fifth thought: the right driver
A driver for a BR should be the right driver for a TML. Qts around 0.25 – 0.4 should work fine
Starting the calculation:
First we need the optimal BR volume (VBR) and calculate it with the factor.
(-> formula 1)
Simplified we can calculate the tuning frequency (fVTML) of the driver in that volume.
(-> formula 2)
The tuning frequency of the TML length (fTML) should be between the free air frequency (fs) and the tuning frequency (fVTML) of the driver in the volume.
(-> formula 3)
We get the length with:
(-> formula 4)
When we have found out the optimal volume we can calculate the starting and ending sections. All we have to do is to convert the formula for the volume. The requirement is that the sections stand in a certain percentage.
(-> formula 5)
(-> formula 6)
(-> formula 7)
Opening section is than:
(-> formula 8)
Than I have placed the driver at 1/3 of the TML-length and simulated a drive I am playing with right now.
Attachments
One small detail and I'll look over the rest for some time before I answer to your thoughts in detail. My problem is, how does the sound get to the "tube"? Or, have you just not cut the necessary wood for the transmission to the tube.
Hi @ll
I dont know how I can post an excel-sheet but if you give me your email I can mail it to you.
best regards Till
I dont know how I can post an excel-sheet but if you give me your email I can mail it to you.
best regards Till
GOTCHA! Looks great from what I can see. Also, what wood are you using for the curves in the line?
I too would like the spreadsheet.
I'd also like those FX200's. haha
If only they were still in production
The project looks good so far.
Josh
I'd also like those FX200's. haha
If only they were still in production
The project looks good so far.
Josh
latest update
here is my last picture. Next week I will build in the Coral 8A-70. Right now a 17cm Philips fullrange speaker is added.
The sound is getting better every hour. The woofers are new and the sound was a bit strange in the beginning. Now it is getting better and better
cya Till
here is my last picture. Next week I will build in the Coral 8A-70. Right now a 17cm Philips fullrange speaker is added.
The sound is getting better every hour. The woofers are new and the sound was a bit strange in the beginning. Now it is getting better and better
cya Till
Attachments
Wow, you work quickly, is it you week off? Good work none the less, I love seeing your updates. Is there any chance that you'll be able to take any measurements?
HDF = "masonite" here in the US, if i'm not mistaken
you should be able to attach spreadsheets (or zip them up and then attach the zip files)
good work, ...what's the other speaker in the pic?
you should be able to attach spreadsheets (or zip them up and then attach the zip files)
good work, ...what's the other speaker in the pic?
hi zobsky,
wath speaker do you mean? the left is a Fostex FX200 in a BL-horn from me.
And the Coral 8A-70 is an old fullrange speaker with very good parameters as you can see on the datasheet.
The woofer I am using is a Fostex W300A-II
Hi Bose(o)
I don't use measurement but I hope a friend of mine will/can help me out with that. If I have pictures I will post them.
No I am still working 9hours a day. I am working with the TML between 7:00pm - 01:00am.
my motto right now: the day has 24hours. If that is not enough take the night. or you can sleep when u are dead.
wath speaker do you mean? the left is a Fostex FX200 in a BL-horn from me.
And the Coral 8A-70 is an old fullrange speaker with very good parameters as you can see on the datasheet.
The woofer I am using is a Fostex W300A-II
Hi Bose(o)
I don't use measurement but I hope a friend of mine will/can help me out with that. If I have pictures I will post them.
No I am still working 9hours a day. I am working with the TML between 7:00pm - 01:00am.
my motto right now: the day has 24hours. If that is not enough take the night. or you can sleep when u are dead.
Attachments
Hi,
since yesterday evening the TML is playing with the Fostex woofer and the Coral fullrange speaker.
So far I am very happy with the sound. The TML is playing very deep and with a lot more control than the FX-horn. Sometimes you have the feeling that the woofer is not on and as soon as you want to check the wireing you can feel and hear the bass. It is never intrusive (??) or booming.
The sound of the Coral is fitting perfect to the sound of the Fostex.
I will play the next days with the volume and the X-over.
cya Till
since yesterday evening the TML is playing with the Fostex woofer and the Coral fullrange speaker.
So far I am very happy with the sound. The TML is playing very deep and with a lot more control than the FX-horn. Sometimes you have the feeling that the woofer is not on and as soon as you want to check the wireing you can feel and hear the bass. It is never intrusive (??) or booming.
The sound of the Coral is fitting perfect to the sound of the Fostex.
I will play the next days with the volume and the X-over.
cya Till
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