Mittwoch, 24. August 2011

Speaker run-in/burn-in/play-in/....




Last week I had a moment of pure joy and happiness right before I entered a state of shock and a few hours later some kind of relief.
Pure joy and happiness: finishing my DIY speakers.
State of shock: hearing them for the first time.

I got some nice ingredients like ScanSpeak 18WU-4741T00 and D3004/664000, Mundorf copper foil coils, Jensen copper foil capacitors for the tweeter and Clarity Cap ESA for the midwoofer side of the crossovers and Kimber 8TC for internal wiring and birch multiplex. Crossovers are piggypacked in seperate, decoupled wooden boxes on the back of the cabinet, speaker cables directly soldered to the crossover avoiding cost and possible soundloss from whatever terminal.
I put on a record, turned up the volume and my happiness was gone.
No bass, awfully harsh highs and dominant mids that made everything sound hollow. After spending a lot of money on parts and a lot of time on refinement of a given design it's horrible to get the feeling you could have gotten other worldly better speakers for half the money in one afternoon without construction time, dirt, effort and all that. But hope was not all lost, so I connected my computer to the preamp and fed my system with pink noise and left for a few hours.
I turned on some music and had the feeling there's potential for a happy end. Emphasis on mids gone, highs sweeter, still little bass. What made me uncomfortable was that the midwoofer on the one speaker was moving a lot less than on the other. I checked my crossovers, found no wiring mistakes and kept wondering.
Then I put my hand over the tweeter. On the one speaker the sound changed a whole lot, on the other I wasn't sure if it did at all or if I tried to imagine it.
A day forward I put on my reference record (Old Man Gloom - Seminar II DoLP). Not the expected weight the vinyl carries. But the chassis on the left and right speakers finally behaved the same. Which I double checked with some mono recordings like the days before.
A few days on with more pink noise and various records at various volumes I'm getting happy again and growing extremely curious about where the changes for the better will stop. Jensen claim 600 hours maturing time for their paper in oil capacitors so it won't get boring.




I have been playing around with the "paddle" the tonearm is mounted to. Originally I had planned to mount a double paddle, one on top, one on bottom and connected to each other. I went for the single paddle, damped with bitumen on the underside. Now I tried various feet, spikes, blocks of wood, POM and cork between the paddle and the rack. Changes in sound: none. Quite interesting. Maybe it's a sign that my system is at it's upper edge., maybe I'm deaf or maybe by accident my tonearm is VERY well constructed as is.
Apart from that I spent the last six or so weeks calculating and building a new pair of speakers. Details and picture are to follow.
Record currently playing: Phillis Dillon - One Life To Live 12"