kamppi said:
Earlier in this thread, Bruce posts details of the taller (48") MLTL, which he built with a triangular cross-section. For this one, he used a much wider front panel (about 11"), so less depth. As long as the cross-sectio remains the same, a wider MLTL should be okay. (Jordan recommends the shallower, wider enclosure for a number of reasons - the shape is more akin to an 'infinite' baffle for the driver and the reduced depth means that only higher frequencies are reflected into the back of the driver, which are easier to absorb. The traingular cross-section also addresses this last point.)
planet10 said:
The site has been updated and how has the VTL drawn as a TL only. The TL (as opposed to the reflex or closed box versions) seems to be the one which everyone is building and the drawing should now be easier to follow.
Colin
Colin said:
Low freequencies are still going to reflect -- the time smear will just be less because they didn't have to go so far before they pass back thru the cone (the Jordan cone is likely fairly opaque). HF are easier to absorb, but with less distance, you also have less distance to absorb them in, so they can be more of a problem than with a deeper box.
All-in-all the triangle is a good solution. Pretty too.
dave
I did some measuring 
My MLTL is quite narrow, only 16 cm. I measured the frequency responce with the narrow baffle (bottommost) but also with 56 cm wide baffle (middle) and 56 wide baffle with the extra bords on the cabinet sides tilted about 20-25 degrees forward (topmost). According to these measurements MLTL works best with wide baffle.
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/Jordanbaffelilla3.png
The graph is quite reliable from 200 Hz to 20000 Hz. I had the mic about 50 cm from the driver.
This is measured from listening point (distance 3.5 m) and the speaker on its normal place:
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/vasen paikallaan.png
My MLTL is quite narrow, only 16 cm. I measured the frequency responce with the narrow baffle (bottommost) but also with 56 cm wide baffle (middle) and 56 wide baffle with the extra bords on the cabinet sides tilted about 20-25 degrees forward (topmost). According to these measurements MLTL works best with wide baffle.
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/Jordanbaffelilla3.png
The graph is quite reliable from 200 Hz to 20000 Hz. I had the mic about 50 cm from the driver.
This is measured from listening point (distance 3.5 m) and the speaker on its normal place:
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/vasen paikallaan.png
I thing that Jordan JX92S MLTL will be my next speaker project!
I was thinking to build something with Fostex FE166e.They're more cheap than Jordan's.But after looking the VTL design from Jordan's site
(they look wonderfull) and read some threads/posts over here I change idea.
I thing I'll give a try with Jordans.
But...
Jordans are not so sensitive like Fostex.And this is a main reason not to use them.I'm a tube lover.So which from the two is more perfect for tube amps around 10W?
Please tell me something to change my mind and go with Jordans?! VTL and MLTL designs look so beautifull.I can't wait to see the trapezoidal MLTL.
I was thinking to build something with Fostex FE166e.They're more cheap than Jordan's.But after looking the VTL design from Jordan's site
(they look wonderfull) and read some threads/posts over here I change idea.I thing I'll give a try with Jordans.
But...
Jordans are not so sensitive like Fostex.And this is a main reason not to use them.I'm a tube lover.So which from the two is more perfect for tube amps around 10W?
Please tell me something to change my mind and go with Jordans?! VTL and MLTL designs look so beautifull.I can't wait to see the trapezoidal MLTL.
DIAR said:
kamppi said:
would this mean that one should use a 1.5 way wit the JX92 with the second driver facing the back. if so i have 2 questions.
Q1: how does one build the MLTL with 2 drivers
Q2: since the JX92 is so expensive any recomendations for a second driver that can be used on the rear?
navin said:
Martin King examines the two-driver approach here:
http://www.quarter-wave.com/General/Two_Drivers.pdf
that pdf does cover the maths involved but a MLTL would require one end closed and one end ported.
see
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/GM MLTL V2.gif
http://www.diyaudio.com/forums/showthread.php?s=&threadid=38755&highlight=
see
http://kotiweb.kotiportti.fi/audiovideo/DIY/Jordan/GM MLTL V2.gif
http://www.diyaudio.com/forums/showthread.php?s=&threadid=38755&highlight=
GM ML-TL
I finally finished my version of GM ML-TL. Earlier I had a VTL which is presented on Jordan webpage so I know what JX92S is capable of. I decided to do 30cm wide GM ML-TL. Depth is only ~8cm. Shape is very similar to VTL, except the driver positioning.
Now I have listened to GM ML-TL for two days I did not need to burn in JX92S's, since they are already about 2 years old.
Sound is pretty similar to VTL, but bass reproduction is tighter. I had to adjust the amount of stuffing two times. Now light stuffing is placed only on the back wall behind of the driver and upwards.
Upper bass region sounds little bit colder compared to VTL. I remember when I listened to VTL for the first time two years ago, I heard some coloration in the bass reproduction and I must have got used to it. Now after two years I built GM ML-TL and coloration is disappeared...
Biggest difference is in the bass region-> GM ML-TL performs better. I am surprised how detailed, clean and deep bass this 4 inch driver can produce.
In my opinion baffle step correction is not needed.
As you know, this is a great speaker! Thanks GM!
I finally finished my version of GM ML-TL. Earlier I had a VTL which is presented on Jordan webpage so I know what JX92S is capable of. I decided to do 30cm wide GM ML-TL. Depth is only ~8cm. Shape is very similar to VTL, except the driver positioning.
Now I have listened to GM ML-TL for two days I did not need to burn in JX92S's, since they are already about 2 years old.
Sound is pretty similar to VTL, but bass reproduction is tighter. I had to adjust the amount of stuffing two times. Now light stuffing is placed only on the back wall behind of the driver and upwards.
Upper bass region sounds little bit colder compared to VTL. I remember when I listened to VTL for the first time two years ago, I heard some coloration in the bass reproduction and I must have got used to it. Now after two years I built GM ML-TL and coloration is disappeared...
Biggest difference is in the bass region-> GM ML-TL performs better.
I am surprised how detailed, clean and deep bass this 4 inch driver can produce. In my opinion baffle step correction is not needed.
As you know, this is a great speaker! Thanks GM!
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