Hi romasn, i send you e-mail with the T-S parameters ARN930 15ohm (too with rubber edge).I know, it´s 15 ohms, and you have 8ohm. But maybe you do a little help.

Thanks man. I have got the e-mail form You. I tried to measure parameters for my arn938 and parameters is quite diferent from your measurements (Qts = 0,52, Fs = 20 hz). But it is a problem with "Vas" measurement for me. I have no a suitable test box for measuring "Vas". I think, "Vas" will be different too. I can' t find any information about "Vas" or other parameters of arn938 on the internet. It is bad...

I would just add that Tesla speaker parameters are often very different. The parameters are varied, depending for example in manufacturing, production development (production series), or too how much was speaker used.

Parameter VAS = equivalent volume, does not specify how volume the speaker cabinet should be. Here is a description of the TS parameters, please use google translate for translation to your language.

More pieces TS
viewtopic.php?f=8&t=2933

Thanks for a lot of information! If I understand properly, the mass of arn930 diaphragm assembly "Mmd" is about 110 - 120 g (exluding weight of air and added masses). The only difference between arn930 and arn938 is impedance, as I know. So the mass of diaphragms should be quite similar for these two speakers? If yes, then I could calculate the "Vas" of my arn938. Or am I wrong?

Yes. One diference between these speakers is impedance, but I never saw ARN938 in originaly configuration. Because TS parameters tolerance are wide I advice you to measure your unique piece and no depend your mind on extraneous measurment. Use only as oriantation point.

http://www.upnito.sk/imggal.php?viewGal ... 5b970712c1
Hello, Romasn.
This is ARN938, custom made from 15ohm version. Only coil is new, wound on the kapton former. Height is as original. Parameters can be maybe similar with yours pair speakers.
I think, 150-200 liter closed box is optional for this speaker. I have ARS850 and listening it daily 3 years.

I think, I will try to make a closed box about 200 liters. Will see, what happens. Thanks for everybody, who tried to help me.