MY DIY transmission line scanspeak revelators and subwoofer

[soundsgreat]

Hi,

Suri you are most welcome Buddy ! Hope that helps you !

One thing,could you please let me know what exactly that madisound offers that you were interested in buying and how much does cost ?? coz if its really worth then perhaps we can chip ( we as in me you and whoever else is interested ) and buy that unit and take our measurements and pass it to the other member ! finally after everyone is done with their measurements,someone who wishes to pay can keep it !!

Let me know your thoughts on this !

As with Auditioning my stuff you are most welcome for that aswell !! anytime you are in Bangalore just give let me know !!

Btw still waiting for the details !!

Regards.

 

[suri]

Great looking speakers Suri
One more core DIYer adding to the list!!!!!. Hope to see more good closeup pictures. BTW how much did the drivers cost?



Regards,
Anil

hi anil,
the cost was midwoofer = $232 each and the tweeters were $ 217 each
sister got them for me, and they were bought at Madisound.
the first picture is a failed project of mine
the other pictures of the latest during the construction phase

 

[suri]

Hi soundsgreat,
i worked with making enclosed transmission lines (in which the loudspeaker enclosure contains the back of the transducer, the transmission line, the stuffing and the transmission opening) and found that the sound was too bass heavy and "rich". the sound did not have the "immediacy" that I wanted, you know the feeling that either "you are there" or at least "the performer is here" kind of thing. Then one day I went to cochin to listen to jacob's rethm speakers (you can see them at Rethm: the full range, single driver, voice coiled loudspeakers using Lowther). And I will never forget the experience - he played Stevie Ray Vaughan's "Tin Pan Alley" and it was just so real.
it was after that i felt that the stuffing in the transmission lines and the inevitable box resonances were robbing the reproduced sound of it's full quality and emphasizing the lower bass frequencies at the expense of upper bass and mids. i made thicker and "very dead" transmission loudspeaker cabinets, but the music remained bass heavy. I then theorised that locating the entire transmission line outside the main loudspeaker housing would give better results due to the fact that resonances could be dramatically reduced and acoustic stuffing could be done away with.
there is a diagram of this theorised enclosure in my reply to Anil Kumar in this thread of the forum
i have two pictures of my early attempts at single driver transmission line. the fs of this bose driver was 150hz, i think
through lots of "golden ear tests", i have found that a tapering transmission line works best, with the the surface area of the end of the transmission line opening being one fourth of the radiating surface of the driver. i have a friend who is a professional musician, who is my "golden ear"!
the (third) picture of the red rimmed two way (black and red) speaker is the progenitor of the present latest project. That project was successful too
and the drivers were peerless midwoofer and scanspeak tweeter
I now think that two-way is the best compromise in reproducing sound, with a good subwoofer to augment non-directional sound below 60 hz.

 

[kaushik]

Hi everyone,
Can somebody on this forum give me leads on how to get measuring equipment (microphones, software, other hardware)

Over the audio forums you will get detailed guides of measurements


some tools are :
-soundEasy - is one popular tool
one good flash based tutorial:SoundEasy Flash Tutorial

SoundEasyYahooGrp

-FRD consodium xls sheets

-Speaker workshop:[As in ASAWARI link given by soundsgreat]
SpeakerWorkshopTutorial


For improvements a detailed book on Acoustics like
"Master Handbook of Acoustics" by F. Alton Everest will help.

 

[grubyhalo]

Suri,
All your project seems to have that exceptional design and execution touch. You should be one patient man with an awesome carpenter to boot!
Congrats!

 

[suri]

Hi grubyhalo,
You have hit the nail on it's head!
That carpenter has hands given by God and it is only because of him that I could translate theory into actual things.
His name is Bharatan and I have attached photos of him working
And it is because of his exceptionally fine work and ability to work with close tolerances, that all the enclosures are made with interlocking joints and absolutely no metal or nails have been used for the construction

 

[suri]

Hi,

Suri you are most welcome Buddy ! Hope that helps you !

One thing,could you please let me know what exactly that madisound offers that you were interested in buying and how much does cost ?? coz if its really worth then perhaps we can chip ( we as in me you and whoever else is interested ) and buy that unit and take our measurements and pass it to the other member ! finally after everyone is done with their measurements,someone who wishes to pay can keep it !!

Let me know your thoughts on this !

As with Auditioning my stuff you are most welcome for that aswell !! anytime you are in Bangalore just give let me know !!

Btw still waiting for the details !!

Regards.

Hi soundsgreat,
sorry for the delay in replying re the measuring equipment. I basically wanted to source a good microphone, a pre-amp for the microphone, and software and i think somebody on a forum recommended soundeasy. I have not researched this, because whenever I had some money, my priority would be speakers, and so I suppose your idea about a few of us sharing the cost would be a good idea, because after all each of us will probably need to use it once a year at most
if i remember right, the cost for the three about three years back was Rs. 26,000 (dollars US converted at that time)
Tell me yourt thoughts on this
cheers Suri

 

[soundsgreat]

Hi,

Hey Am sorry too was bit pre-occupied with stuff so only couldn't reply to the earlier post !

i worked with making enclosed transmission lines (in which the loudspeaker enclosure contains the back of the transducer, the transmission line, the stuffing and the transmission opening) and found that the sound was too bass heavy and "rich". the sound did not have the "immediacy" that I wanted, you know the feeling that either "you are there" or at least "the performer is here" kind of thing.

Well the basic transmission line theory itself is to make the bass response extended well below the Fs of the driver !! so no matter what you do the sound will have a TL character ! but thats not bad ! coz if done properly it can give sub a run for its money in any stereo setup ! But this is again a very very subjective matter ! so will leave it at that ! Just like to add one thing here (please don't mind ) but the normal TL or TWQT done properly can have a mids to die for ! have heard some and can only appreciate the sound ( I don't have golden ears but have to manage) ! so perhaps when I hear your set-up I can get the feel how what your tastes are (coz I have rarely seen very very few who have similar views on the TL design as you ) !

the surface area of the end of the transmission line opening being one fourth of the radiating surface of the driver.

On the above theory,Well its not at all the regular way of doing ! coz in any and almost all TL designs,the Mouth (or opening or end of the TL) area will be either double (some times triple ) or atleast the same as Sd of the driver ! so this is new to me and makes it a must see !

As with the other projects of yours,just loved the pics so will surely like to see them one day !


Now coming to the latest post, Ohh ok so what you wanted was to buy a Mic+Pre+Software ! Hmm the said 26K is bit on the higher side but if its worth then we can give it a try !

Having said that I"ll tell you this,The soundeasy (The soundeasy I suggested with the link to the Asawaari project where its used ) will do the job just fine with the basic stuff as they have covered all the inefficiencies of the regular (non Reference grade) components we may use in the setup ! The manual also very clearly stats that you do not need a Reference grade amp to output the Signal Sweep ! and also some decent quality Mic will do ! so if we go this way the cost could be hardly 2K (not including the software as it costs 250$ and is a single user license,so no sharing possible :indifferent14: ) ! I have studied that soft and is very very good and be used reliably !

Also there is an Indian company called AudioLec in Pune who have customised solution for this ! it includes hardware and software package ! they say its used all over including the some TOP rated Indian Speaker Brands ! but the only issue is the cost :sad:! as its priced at 70K !

Anyway thats what I think bout the thing ! Hope you don't me being very straight (coz thats how Iam ) ! please don't take anything in the negative or the wrong way !! I wrote what I felt like !

Regards.

 

[suri]

Hi soundsgreat,
thanks for the post much appreciated.
as you have said, the classic transmission lines as described, isolate the back waves, attenuate the high frequencies in the back waves to near zero, allow the lower bass frequencies with longer wavelenths to exit the transmission mouth in phase with the front waves, so that the bass frequencies get a boost. These have stuffing to absorb the (shorter wavelength) high frequencies and a transmission mouth which is as large or larger than Sd.
And like you say, all of them have a "TL sound" which some do not like, and I really do not like. They have overemphasized bass and not much "Presence"
So I tried the following - did away with stuffing, tried longer lines, and smaller mouths - No stuffing and large mouths suffered from a "vagueness" - ultimately what worked was what you see in the pictures - no stuffing , the transmission line being located outside the transducer chamber, tapering transmission line and mouth of transmission being about one fourth of Sd

But there is a caveat - IT WORKED FOR ME - and thereby hangs a tale -

Lots of people come to listen to speakers and it usually goes like this-
after the listening session they say -"fantastic clarity, very good" and then
"I have a good system in my car, would you listen?' .So the CD is taken to the car, and the 2 lac system goes into action with "SAKKAT BASS"
the whole car resonates and every type of distortion is evident, but at the end of the session, the owner implies that my speakers are not as good as the car system; one owner consoled me by saying "You see, the bass is very good in my car because six speakers are producing the sound and that is why you can feel the power"
So I think that very few people will like the "speakers that Suri built"!!!:sad:

 

[soundsgreat]

Hi,

"TL sound" which some do not like, and I really do not like. They have overemphasized bass and not much "Presence"

Suri I can understand what you mean by this ! its your personal choice and there's nothing wrong in it !

So I think that very few people will like the "speakers that Suri built"!!!

Man I tell without even hearing it,If someone doesn't like these beauties either he has no clue of what a quality audio is ! or he's too jealous of this and doesn't want to show it you ! otherwise anyone with some amount of knowledge will only appreciate the quality, be it the workmanship or the overall design and finally the sound !

I wish you were nearby to visit :indifferent14:!! well anyways will surely try to make it sometime ! again need I remind you that whenever you are in Bangalore you are most welcome to visit me !

Regards.

 

[suri]

Soundsgreat,
on a side note, I am not sure that what I have made can be called a transmission line speaker, because by definition, the transmission line (a term borrowed from electrical engineering) is designed to completely attenuate the higher frequencies and most transmission lines require that acoustic stuffing is used.
so what do I call this?

 

[suri]

FAILED PROJECTS!
MONUMENTAL FAILURES:sad: