giovanni56

I also answered about the same question

The filter diagram I attached fits the 2010 Scanspeak tweeter which is 8 ohms. Everything is described in the thread. You have to eliminate the 6 nF capacitor and exclude the potentiometer that are part of the fitro for the Ar3a 4 ohm tweeter.

Hi Giorgio, yes, I have the measurements of the woofer and tweeter Ar/TNG, as soon as I recover them I'll send them to you on Whattsapp; given the treatment, I think I won't post anything here anymore

This is the last pair of Ar LST's I restored about a month ago. The owner's name is Marco, he lives in Pisa. He brought them to my home in Ravenna as several other owners of Ar speakers have done over the years to entrust me with the restoration or maintenance, so I had the opportunity to test and measure several drivers. I own a pair of 200010-1 midrange speakers that I jealously guard as a spare and do not sell. I joined this group because since 1970, I have been an Ar enthusiast. I joined because I like to compare technically, with due respect and education to all, no one excluded. I'm not a salesman and it's not my habit to tell lies. What I have stated in my previous posts on this thread is due to technical considerations, but I respect your opinion that comes from your decades of experience in the field. This is not a competition between you and me to see who can piss the farthest. Best Regards Giovanni

Very nice, congratulations!

Every time I restore a speaker I measure all the drivers and, over the years, I have measured a lot of them, I have restored three pairs of Ar LSTs that have a total of 24 midrange drivers and many other Ars with the 200010-1, so thirty might be a few. It is true, as we age, the Fs of the drivers decreases but, if Ar claims 400 Hz for its new 200010-1 midrange, I would have expected that the ones I measured, being old, would have values lower than 400 Hz. In my opinion the mid 200044 is not compatible with Ar11 (and similar), with a cut between woofer and midrange at 525Hz because it has a too high Fs that is not mechanically controlled with the external damping wool held on the dome by the external grid as on the midrange 200010-1.

I measured at least thirty Ar 200010-1 midrange drivers and six Ar/TNG 121010-, the lowest Fs was 458Hz in the Ar/TNG, while in the Ar200010-1 550/580Hz, I never found a driver with Fs of 400Hz, while in the 200044 that I measured the Fs values varied from 685Hz to 730Hz, for this reason I consider the 200044 midrange not compatible as a substitute for the 200010-1 without having to modify the crossover filter for eventual use in the Ar11/10, Ar3a/Ar3a Improved.

The attached filter scheme is deliberate, to be used on Ar3a and Ar3a Improved but also on Ar11 and Ar10pigreco

If you have Ar3a's, I don't understand the reason to build a new crossover filter, the Ar3a's sound good with the filter that Ar came up with, it doesn't make any sense to change it, especially in the way you outlined.

But which speakers are you going to install those tweeters in?

The coil is used to increase the attenuation slope of frequencies below the Fc of the tweeter's high-pass filter to avoid "breaking" the component

MidWest MT 4121-4 4ohm. Ar3a, Ar3aMigliorato, Ar11, Ar10pigreco, Ar LST MidWest MT 4121-8 8ohm Ar5, Ar2ax, Ar LST2. On Ar3a and ArLST the filter must be modified by adding an inductance of 0,105 mH in parallel to the tweeter that must be connected with inverse polarity, same thing for the 8 ohm tweeter on Ar2ax, Ar5 and Ar LST2, but with inductance of different value 0,15 mH.

I think the 8ohm constant impedance L-Pads, need to be replaced on both mid and tweeter, the 4nF capacitor for proper high pass operation needs to see the original 16 ohm rheostat load and the tweeter load 8 ohms as originally (same thing on the midrange).

The Ar2ax do not come with black knobs, but with an arrow engraved on the potentiometer shaft. If the potentiometer is fixed in place with the socket in the masonite, to make the measurement you put the dart on the white dot and measure the R between B and 1 of the rheostat. It should be 6 ohms for the midrange and 4 ohms for the tweeter.

The tweeters are always better to be in pairs, then given the age, it would be necessary to disassemble them both, arrange them, check them to align as much as possible the T&S parameters

There are audio experts who claim treated paper as one of the best materials for the construction of speakers (woofers, midrange and tweeters); the problem is the cost of production of good paper membranes, for example on woofers is cheaper and more repeatable, build a metal cone than a cone in treated paper.

Mr. Allison designed his tweeters and midranges with the goal of the greatest possible off-axis dispersion, and the domes were made of stiff paper. I think he would not choose either Ar tweeter, but would reuse his own. For a new design with modern drivers, perhaps he would consider using the Dynaudio D21AF, Vifa DT19 or Scanspeak D2010 as tweeters and the Dynaudio D52AF or D54AF, or Scanspeak D3806 as midrange.

I have a feeling the 3.2 ohm tweeter has already been repaired, the 1.1 ohm tweeter has a shorted coil. They can be restored, but it's an awfully "heavy" job, among other things it takes a lot of time

Grazie, Giorgio, buon ferragosto!

I don't know, however these are made in the USA but have the same carryover on the edge

If you lived in Italy, I could have rebuilt them.

C'è solo un'etichetta accanto ai morsetti di connessione, nella porta non ci sono etichette. All'interno delle custodie ci sono due etichette spartane che riportano gli stessi numeri di serie di quelle esterne. 1089 1293

These are my Ar10pi

Giorgio, the woofer 200003 used in Ar3a is ok for LST, but also the more recent one used in Ar10p/Ar11 with the white on black logo. The TNG is equally good, I have measured several of them and the differences are really minimal, if you adjust the Qtc of the speaker by changing the amount of glass wool, the bass of the TNG is practically, equivalent to that of its American cousin. The TNG can handle a little more power and is less prone to bottom out.