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In the Forum: Horn-Loaded Speakers
In the Thread: Vitavox S2 with Electromagnets
Post Subject: Some data about the S2 filed coil. Posted by Romy the Cat on: 4/25/2006

The played today a little with Vitavox S2 driver with electromagnet and made some measurements. Measuring the relative magnetic force (I use Hirst GM04)  I found out that increase current up to 3A linearly increases the magnetic force in the gap. I did not go over 3A but it looks like the core was quite far form susurration at 3A. Sonically the change of current also hugely affects sound, primary transient characteristic. I did not listen music and did not put driver in a horn but juts listened a few test cuts with naked driver at different currents. I do not know if it sounds good but I cat testify that it sounds VERY different at different currents. It sound more deferent then it might be predicted form the frequency sweeps that I provide below. I would withhold as this point from any judgmental comment and juts share the raw data.

Those sweeps (it is not 1W of course) were made by a naked driver sitting at 3 feet from my calibrated instrumental microphone. The first and the last sweeps as the Vitavox S2 drive with permanent magnet and the original metal suspension diaphragm. Do not be afraid of what you see: this is perfectly normal response of a naked driver that is not EQed by a horn. The sweeps were driven by the HF channel of Super Melquiades with 3700Hz high pass filer, first order. After the permanent magnet sweep was done the diaphragm with the back plate was detached and attached to the filed coil driver that was positioned into the very same location. Then the sweeps were made with the Vitavox S2 armed with electromagnet at the different currents.

Above the S2 driver with a permanent Magnet

Above electromagnet at 0.6A


Above electromagnet at 1.0A

Above electromagnet at 1.4A

Above electromagnet at 1.6A

Above electromagnet at 2.0A

Above electromagnet at 3.0A

Above again the S2 driver with a permanent Magnet

I will provide further listening assessments later on… when I have them….

Rgs,
Romy the Cat

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