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In the Forum: Horn-Loaded Speakers
In the Thread: Vitavox S2 with Electromagnets
Post Subject: Learned from S2 electromagnet: LowthersPosted by Romy the Cat on: 5/9/2006

I gave another run to Vitavox S2 with electromagnet and while I was listening I come across to an interesting observation. I screw the S3 in 330Hz horn and was trying to run it with 500Hz crossover point. It is pretty standard configuration, the way in which Altec, JBL, Vitavox and many others. This setting never produces good results (due to multiple reasons) but I did not search for result but was interested how the S2 with electromagnet would act.

It was kind of predicable. At 3 amperes (at full blow) the electromagnet did OK above 3kHz region and at 1.2A it sounded Ok around 500-700Hz. (Remind you that the electromagnet produces at 2.4A the same flux in the gap as the default Alnico magnet does). However, what was the most fascinating to observe is HOW the S2 with electromagnet sounded at it lower knee.

When I heard the bass of the S2 with electromagnet I suddenly realized that I heard something that remotely resemble the Lowther driver. Let me to explain. Let forget that people out there are using the Lowthers with stupid back-loaded horns and to lets to abstract out the sad contribution of the back-loaded concept (particularly for this driver). So, if disregard the back-horn sound and to pay attention at the lowers Lowther region (200-500) then it is very annoying that Lowther upper bass never free, never has that “fog sound” and always insultingly dry. I always attributed it to always too low crossover point that usually used with Lowther but now, after the play with electromagnet, I have another opinion.

I feel that Lowther is juts have too strong magnetic field for proper bass reproduction. The Lowther people scream that this driver have huge magnet, huge amount of BL, huge flux, super small gap, low excursion and so on…. This is all fine and it does allows to make a very effective magnetic saturation in the gap but it …. horribly affects the lower knee performance of this driver. The Lowther just has too strong and too stiff magnet system that does not allow the driver to play soft…. Apparently it DOES exist a reasonable balance of the flux density projected to the rest qualities of the driver (cone, suspension and so on…) The Lowther is obviously is on the HF side and should not used for any bass. Whatever it does below 800 is very inappropriate… Who knows… If the Lowther would have somewhere around 1.6T in the gap then it might have some lower midrange and perhaps it’s upper mid would not be so barbarianly-resolute.

Rgs,
Romy the caT

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