Tweeter T/S parameters

[youyoung21147]

Hello,

I'm willing to use some Seas 27TBFC/G or Peerless HDS 810921 tweeters at a quite low frequency (say 1500Hz).

For this purpose I have two solutions :

- Linkwitz transform the tweeter
- design a waveguide


Unfortunately, both solutions require T/S parameters of the driver to be accurate...

As far as speaker manufacturers don't publish T/S parameters for their tweeters, I was wondering if it is possible to measure them.


Thanks in advance !

[MJL21193]

You want to Linkwitz transform your tweeter? That is a different idea for sure! Maximun linear excursion for the Seas is .5mm. Freq. response is down only 3-4 db at 1500Hz, overlap from your midwoofer can easily cover this.
I am amazed...

[richie00boy]

As above, tweeters simply don't have the excursion required.

If you insist on trying, there is a guide on my website how to measure most Thiele-Small parameters (including Fs and Qts, which is what you need to know). Written for woofers, but pretty identical process for tweeters, just the frequency band is different.

[youyoung21147]

Lol don't worry, I've made calculations to be sure that I will never need all the Xmax excursion.

Let's say I need 106dB to 110 dB of SPLmax...

For the Seas 27TBFC/G (0.25mm Xmax), Xmax limited SPL is 106dB @ 1700Hz

Or 2150Hz @ 110dB

For the Peerless 810921 (0.5mm Xmax), Xmax limited SPL is 106dB @ 1200Hz

Or 1567Hz @ 110dB


I've been quite suprised by these numbers !