DYI spekaer with Dynaudio Esotar T330

[Richard_Majer]

Hallo, first of all I'm sorry, I don't speak Dutch, only English :-(

I have Dynaudio Contour 2,8. They use Esotar T330 tweter and 20W75 and passive membrane. I'd like to use this speakers (without passive membrane) for DYI project. I'd like to aks you, if you have any advice. For me is important to use at least Esotar T330, which I like very much.

Thank you

Richard

[Richard_Majer]

here are specifications of above mentioned speakers:
20W75
T330D

[fgroen]

The application notes say that the 20W75 is designed for a 18l closed box enclosure. Looking at the Thiele-Schmall parameters this figures: Qts is 0,4 (4 Ohms) or 0,5 (8 Ohms), which is too high for a decent Bass-reflex alignment.

So the original passive radiator design must have been more focussed in quantity of bass than on quality.

I suggest to build a closed box. Do you already have ideas about cross overs? Audiofiel, a Dynaudio enthousiast on this forum upgraded some Dynaudio speakers by increasing the quality of used filter components, with great success.

Here are the topics:

Solen Impression SE
Audience 40 SAE

It might be usefull to get into communication with him.

Success with your project!!

[Audiofiel]

I would also suggest a closed box, because the 20W75 is a very nice woofer, but to get a real tight bass, you must not use a BR with this one.

Are you planning to disassemble the Contour and built a new enclosure or are you planning to built a second pair yourself? In case of the first: why not try upgrading the filters?

[Richard_Majer]

To be honest, my knowledge about speaker parameters are limited, means to seeing them I cannot say what would be the best condition for usage...

I tried to dismount passive membrane and close existing box. It was not good :-( Bass was gone :-(

To modify crossover would be first step. Why not... My initial idea was to build complete new boxes. You know... to be proud of your self that you did some new "child". I did already two boxes. First was for potatos and second project was Ariel (http://www.majerovi.com/richard/Ariel/Ariel.htm)

And what I meant in beginning was to "copy" existing project or try to modify some existing.
Option a) T330 tweter, than , than 20W75 and than . Question marks should be replaced by speakers which I don't know. To use Dynaudio would be the best due to the same design of baskets. It sound childish, but design is part of finale feelings.

b) to use only Esotar and rest from other producer... Eton? SS? Perless? I don't have unlimited budget, therefore would be nice to use as much as possible from existing speaker and for new one not to spend hell of money.

The final system can be active. I can do active crossover and amps. This is manageable.

What is your opinion? Am I dreaming too much? :-)
Thank you

[Richard_Majer]

here are pictures of existing cressower...
http://www.majerovi.com/richard/dyn_2,8_streva/
Coils walue are not mentioned, I didn't measure them

other pictures...
http://www.majerovi.com/richard/dyn_2,8_vzhled/cont_2,8.htm

[Audiofiel]

If you want to modify the filter I suggest you lose the cement blocks (resistor bricks) for metaloxide ones (MOX), and change the capacitors for Audyn Cap MKP + or Leclanchier MKP types. Also, you could use a thicker coil (for less resistance) and hardwire the entire filter (instead of using a PCB board).

[Richard_Majer]

Hallo, I used first time SW for box design. 20W75 with bassreflex can work 30Hz -3dB in existing box with bassreflex 6,8cm diameter and 13,5cm length (used WinISD 0,44) Can you confirm, please?