DIY : Transmission Line Speakers.

pranavkumar

Active Member
Joined
Aug 13, 2012
Messages
160
Points
43
Location
New Delhi
Hi All,

This is my second post on Hi-Fi Vision. I got some positive comments on my post on Hand Wound Inductors, and I hope you guys like this thread as well. BTW, I built the inductors for this project...

I was browsing around and came across an enclosure design on DIY AUDIO PROJECTS - Do-It-Yourself Hi-Fi for Audiophiles and I was adamant on building them. I'm building these speakers not for myself (too bad :/) but for a good friend of mine who really needs a good pair of speakers.

After looking up the enclosure details and specifications, I decided to use the 5.25 Titanium Cone Peerless Mid-Bass speaker and a LR10DT tweeter from the same company. Thanks to Jeetu Bhai in Mumbai, these speakers arrived, and the crossover began taking it's shape.
Jeetu Bhai was kind enough to send me the specs sheet for both the speakers and I was able to analyze the frequency response curve perfectly.

I finally decided on a first order crossover, with the crossover frequency being around 3300Hz. I calculated the capacitor and inductor values, which was easy to do as it was a first order crossover. I wound the inductors and got FAN capacitors for the high pass filter. :)
These capacitors work well for audio purposed too!

After determining the L and C values, I hand wound the inductors and hand wired the crossover.
The enclosures needed a little manipulation as the speaker I was using was a 5.25 and not a 5 one.
These enclosures were made by a skilled carpenter, I would have made them... but I did not have proper power tools to work with, and working with a hand saw to cut a 18mm MDF board was not what I would want to do !!
After two days of carpentry, the enclosures were waiting to be wired. I used a 12mm thick foam to acoustically insulate the sides of the enclosure and filled with some puffs of poly fill in certain areas.

Finally I built these might speakers today and yesterday ! Took a lot of time to do everything, but turned out to be well worth the time ! :)

I was amazed at the speakers, I must say, peerless guys know their business pretty well ! These have by far been the best Indian speakers I have ever heard.
The overall sound of these floor standers is phenomenal :) Excellent lows, immense clarity in the highs and the mids. Loved the Sound ! Absolutely amazing.

I had hooked these speakers on to a 50W Yamaha Stereo Amplifier which got its source from a X-fi sound card attached to my workstation.
Mark Knoflers Guitar and the Fat Groove in The Six Blade Knife sounded incredible.

I'm posting the link to an extensive collection of pictures snapped as they took there shape. I tried to snap pictures at every stage of the build. Might have missed out on a few..
The veneer still needs to go on the enclosures to give it the perfect look !

Take a look! :)
https://plus.google.com/photos/1119...s/5775468020447229953?authkey=CNGUoaaYk7ns2gE

2012-08-11_17-10-43_765.jpg


IMG_0666.JPG


IMG_0681.JPG


IMG_0708.JPG
 
Great !! Nice to see rocket science being de-mystified. As more folks go down
The TL route ... This technique of speaker building will get popular too.

BTW.. what are the external dimensions of the cabinet ?? and the aperture / terminus is on the front side ?

Congratulations.

Mpw
 
Last edited by a moderator:
This is very inspiring and innovative. I keep seeing threads like these and makes me wish i had some garage space to do my own projects. It sucks that I cant.
 
This is very inspiring and innovative. I keep seeing threads like these and makes me wish i had some garage space to do my own projects. It sucks that I cant.

Hey corElement,

I see that you are in NCR, and Pranav is in delhi, so maybe you can be in touch and find a guy to do your carpentry jobs....
 
@mpw:

These are my first DIY TL speakers. I'm discovering new terms associated with this technique. I assume that by terminus you are meaning... the bass reflex opening ? If yes.. then the terminus is on the front side. :) correct me if i'm wrong.
It is a 50mm port ... the length was not mentioned in the enclosure plan... will have to try out different lengths and put the best sounding one. BTW, there is no port in the hole at the moment, and i dont think it needs one :p

The outer dimensions are : h:40.5" d:10" w:7". these are rough figures.. ofcourse the dimensions will change by changing the configuration of the wood planks (keeping internal dimensions same).

Thanks again !
 
Don't u think the xover is too high at 3300hz. Can u set it lower and experiment.
Our FM Hari Iyer is also into TL speakers maybe he can guide you further.

Rgds
Mpw
 
Our FM avidyarthy in delhi also owns TL speakers. Maybe you could linkup
Too and compare notes.

Rgds
 
Great Wood work and images. If i understand the images correctly, it seems the open end has a larger cross-section area than the closed end and you will be using some kind of port for the terminus or may be mass loading the line. The line is tapered and the driver is off-set at 1/3rd of the total line length. Take care of the back pressure from the woofer due to lower cross-section area just behind the driver as this might cause standing waves right behind the drivers. Needs to be intelligently damped. How have you calculated the damping requirements for the line? Will be interesting to know.:clapping:
 
Great Wood work and images. If i understand the images correctly, it seems the open end has a larger cross-section area than the closed end and you will be using some kind of port for the terminus or may be mass loading the line. The line is tapered and the driver is off-set at 1/3rd of the total line length. Take care of the back pressure from the woofer due to lower cross-section area just behind the driver as this might cause standing waves right behind the drivers. Needs to be intelligently damped. How have you calculated the damping requirements for the line? Will be interesting to know.:clapping:

Hi,
Thanks for the comment ! :)
I assume you are a pro at all this, could make out by the terminologies used in your post ! I'm an amateur DIYer.... i really did not think much about the damping too much and followed whatever the enclosure designer had mentioned. Whatever i did, the overall sound of these FSs are absolutely mind blowing. The lows are so sweet, i cannot explain via TExt :D

I will PM you, and maybe you could distribute some knowledge, will be much appreciated :)

I'm also linking you to the project site, do check and let me know if i made a mistake somewhere : Fostex FX120 DIY ML-TQWT (Transmission Line) Speaker Project

Thanks again !
 
Another DIY dude with great woodworking skills. Congratulations for the build. Hope to listen to them sometime.

Yes, i actually screwed up a little on one of the cavity for the mid bass driver. I bored in a little extra. Had to fill up with m-seal ... you might have seen a picture of it in the collection. after it dried, i used a file to make a perfect circle.:)
Thanks man !
 
I suppose everyone here knows about peerless india and the drivers that i've used in this project.
As this set is for a friend, im also looking for a stereo amplifier to go with these. The Amplifier that i'm using right now is Yamaha RX 397, and it sounds incredible.

can anyone suggest a good amplifier, not too expensive (under 15k) which would go with these ? a second hand amp would also do !

Thanks for the help!
 
Hi,
Thanks for the comment ! :)
I assume you are a pro at all this, could make out by the terminologies used in your post ! I'm an amateur DIYer.... i really did not think much about the damping too much and followed whatever the enclosure designer had mentioned. Whatever i did, the overall sound of these FSs are absolutely mind blowing. The lows are so sweet, i cannot explain via TExt :D

I will PM you, and maybe you could distribute some knowledge, will be much appreciated :)

I'm also linking you to the project site, do check and let me know if i made a mistake somewhere : Fostex FX120 DIY ML-TQWT (Transmission Line) Speaker Project

Thanks again !

I went through the link, but this project was meant to be used with the Fostex driver. Hope you are also using the same driver or a driver with similar TS parameters. The line length, damping coefficient and cross section area varies with the driver and cannot be directly substituted. The harmonics will not match with the acoustic impedance and you will need to experiment with the damping in case you hear some mid-range anomalies. The acoustic impedance is important to have the low frequency lift you get from the line length or you risk having standing waves in the line.
 
Get the Award Winning Diamond 12.3 Floorstanding Speakers on Special Offer
Back
Top