Vifa D20TD-05-06 replacement help

[Flappytango]

Hi,

I have a pair of 2 way bookshelf speakers and one of the tweeters was physically damaged by my friends kids.

I opened it up the speaker adn teh tweeter is a vifa D20TD-05-06 3/4 soft dome. I think it is available but i would not mind upgrading the tweets in both speakers.

I am open to suggestions but want to stay below say $45 dollars each tweeter.

D20TD-05-06 specs

Voice coil resistance [ohm] 4.2
Sensitivity [dB] 89
6 ohms *DC resistance: 4.2 ohms *Fs: 750 Hz *SPL: 89 dB 1W/1m Free air resonance [Hz] 1700


I was already planning on building new cabinets for these speakers so it does not have to match in size.

According to the manufacturer my speakers are crossed over at 2500Hz

i was looking at PE site and there are some 1 inch soft domes i thought i could try.
like VIFA PL27TG-35-06
6 ohms *DC resistance: 4.6 ohms *Frequency range: 1,500-25,000 Hz *Fs: 750 Hz *SPL: 91 dB 1W/1m

Could i just pad this down a bit to because of its greater sensitivity? Or does its higher DC resistance cause more problems.

the tweeter section of the crossover seems simple with a 3.9uF cap in series and an inductor parallel. not sure of the inductor value i will try to get them measured.

good ideas or suggestions apreciated.

[Flappytango]

ok well i might just try it without advice.

I am a better wood woker than audio circuit designer and i will be gluing up some cabinets i cut yesterday. I just need to decide if i will change tweeter or not so i can route the speaker recesses and holes

If i change tweeters i understand that some crossover adjustments may be needed. So i am looking for close match in dc resistance, sensitivity (but i understand how to l-pad so not critical).

what im not sure about is Fs? how will this effect choice for a tweeter?

I also will try to find a similar impeadance curve. I am assuming that the Impeadance should match well around the crosover frequency and beyond that not make much difference. Am i correct??

[morbo]

personally I would be trying to find a tweeter that is as close to the original in sensitivity, FR, and impedance as possible. Vifa still makes D19/20 series tweeters as far as I know, so you should be able to find a drop in or close to replacement. If you try to upgrade without any measurement/design capability, you could as easily degrade the sound as improve it IMHO.

[Andy G]

It is very nice tweeter, much better (IMO) than the D19.

Stick to the D20, any "upgrade" will require totally reorganising the x-o.

[Flappytango]

thanks for your thoughts

i just might by the direct replacement.

I dont mind playing aroung with the crossovers though because a couple of years ago i totally rebuilt the xovers. I just copied the originals with quality components but split out the tweets and woofers to biwire.. (I had te electronics shop where i used to work measure the coils). I have many resistors from trying differnt pads on my car tweeters.


As far as messing up the original sound am i correct as follows?


Lets say my xover is 2500hz and the original and replacement tweeter both have flat response and similar impeadance in the region then it would be a pretty good match.

but voice coil resistance is higher on the replacement. this will shift the xover to higer frequency right?

what im sure i dont know is how Fs effects things if it does?

ehh if i screw it up ill just put the old ones back together give them to my brother and start a project aroung the new tweeters

[Andy G]

if 4" or less, maybe the OW1 (or whatever the 19mm Hyq is called) would be a possible improvement.. although I have not used it myself, it does get raves form lots of fellow DIYers. Other than that , I'm not sure what else is available that might be considered an upgrade from a D20.

you could go to a 25mm tweet, of which there are several pretty good ones at reasonable prices

[Flappytango]

i was thinking going to a 25mm, the woofer it will mate with is a 6.5" cant tell what make/model

i think i may buy much nicer tweeters play around with them a bit for now and use them in a future established design or kit.

maybe scanspeak d2905/9500 lots of prjects done with these

or Usher 9950C-15 tweeter
there is a 3way (Exodus Audio 641)wth this amd extremis woofer that looks good to me

http://diycable.com/main/default.php

but for use now these are 8ohm not six like my d20