supertweeters + full range - 1st or second order XO

[adamus]

hi,

i have searched around but mostly people on here just use first order at around 15khz for a supertweeter with a fullrange.

I want to play with supertweeter and have ordered some ribbons, question is from experiece, have any of you tried second order Vs first? can anyone explain the difference it made to the percieved sound quality.

cheers

[planet10]

I have on occasion found a 2nd order XO better suited... very system dependent

dave

[Henkjan]

is this when you also filter the full range LP at 15kHz, or when the FR is left unfiltered?

[adamus]

unfiltered

[stevieg]

Have a look at the World Design website - There is a supertweeter .pdf file there with xover

[adamus]

have you got a link, i cant seem to find it.

[bear]

the actual answer depends on a few factors, the biggest one depends on the specific "super tweeter".

It depends on the FR vs. mechanical and power limited excursion of the super tweeter.

In general you can think of the first order filter as keeping the excursion constant WRT to frequency below the -3DB rollover frequency. The question is if that movement becomes unloaded and/or if this level of excursion is in excess of what can be linearly handled there can be IM type distortion or worse actual damage or buzzing of the diaphragm.

EDIT: then the next question is what does the summed acoustic response look like...

[adamus]

The tweeters i am looking at are isodymanic (ribbon) 93db/w and recommend a crossover of >2000hz.

i think the only thing to do is try both.

[planet10]

Originally Posted by adamus

i think the only thing to do is try both.

Yes. With that kind of tweeter, impedance should be fasirly flat, so it shouldn't be too hard.

dave

[PJN]

There is free excel based software available here :

jbagby

that will allow you to model both and see what to expect before putting a lot of time and money into the effort. Highly recommended.

PJN