The A25XL has the same 1.5" tweeter as the A25. The difference is in the woofer - a much better driver with a cast metal frame instead of a stamped frame, and a larger magnet structure.
I have A25XL tweeter(s) downstairs. It is a 1”. The baskets in both the alnico woofer and the newer ceramic magnet woofer have been the same. I have dissasembled at least 2 dozen A25/A25XL/A35/A50XL/A50/A10 as my sample set. I can probably post pictures.
But with over a million of these, by 2 different manufacturers, over such a long time likely means some changes as time progressed.
dave
But with over a million of these, by 2 different manufacturers, over such a long time likely means some changes as time progressed.
dave
Ok, but it could still be that the 27tffc sound better than H087 despite distortion?
27tffc has fs of 550Hz, the H087 has fs of 1000Hz. So will the H087 distort less just because it has bigger voice coil?
Maybe I need to get some H087 and listen...
Wow. Never seen an A50 in person or listened to it!
You are correct, things changed over the course of the production history. My A25XL were purchased near the end of Dynaco's life (before the company that purchased the spare part inventory of Dynaco, and before Panor Corp. purchasing the trademark).
Yes, I am truly sorry that my friend trashed the A25XL and did not return it to me for fixing. Ugh. I'm sure it was the tweeter that burned out and I could have just replaced it.
Seas 25f-ew has a resonance in the air at 26 Hz, in Dynaco the resonance rises hertz to 60, but in a closed box = 70 liters its resonance drops to 42-44 Hz (-3 dB) and here he doesn’t need any subs.
Its sound pressure drops exactly above 1 kHz and no filter is needed.
Attachments
Ok, but it could still be that the 27tffc sound better than H087 despite distortion?
27tffc has fs of 550Hz, the H087 has fs of 1000Hz. So will the H087 distort less just because it has bigger voice coil?
Maybe I need to get some H087 and listen...
The manufacturer recommends for 27tffc above 2 kHz, 2nd order. It is right.
I didn’t measure Seas H087, but I have H113, on an alnico magnet, 1.5 ", and its distortion falls immediately after resonance. This rarely happens.
The dome in 1.5 "has a lower limit of high frequencies against 1-1.2", it has a very tasty sound at frequencies of 3-12 kHz. And you can turn on the 1st order.
Measurement sound pressure-distortion, Seas 27tffc, without a filter :
Attachments
Thank you for the info
I cannot find any data on H113, is older than H087?
I bought their box, NOS, on ebay.de. T / C parameters are not found on the site, but not scary - I have microphones and measurement programs.
I make measurements of tweeters on a sweep-tone, 1 W, 0.5-1 meters, but I do not sweep in the entire band - only 2 times the frequency above the tweeter resonance.
Then I transfer the level of THD - total harmonic distortion from decibels to percentages, according to the table. And I choose the filter frequency where the tweeter distortion is reduced to a minimum.
normally, distortion is measured in the near field unless you have an anechoic chamber to measure in. a very large and quite open space will do too. to get accurate results you need to have a large level difference between direct sound and any reflected sound. measured at 1 meter in a normal room then your measurements are only valid at higher frequencies.
I have a pair of Scandyna A25 which as far as I can tell are the exact same speaker, but without the variable tweeter level. A very fun speaker indeed, and the bass driver is great. The tweeter is pretty good too, but not on the same level as the bass. It is very sensitive to bad recordings, and quite tiring in the long run. The Epicure 100 is overall a better speaker IMO, at the cost of less bass extension.
I bought some used cabinets, and made a new baffle, with roughly the same dimensions as the original a25
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.