Intermediate step (Off Topic)

by GC, Saturday, July 16, 2005, 03:04 (6853 days ago)

Hi Bert and all,

A planning mistake, working/studying 56 hours a week is not a good combination with a DIY-hobby. The rare free hours I have left for speakerbuilding are late at night. My neighbours wouldn't appreciate it if I started routing out dozens of circles at those hours. I have had to put my Bold Step on hold (round 120 Hz tractrix horns).

Still, I keep having the itch and I get bored at night, so I dug up the old figure saw and made one 160 Hz horn. It's an odd combination of 4 mm MDF, straight square sections and pur-foam. :-D

It was finished today. I screwed in a Lowther PM6C driver and connected it to my amplifier. Quite horrible sound. Bright, loud and aggressive. I thought it was caused by reflections and resonances in the square horn. I left it playing for a while and it quickly solved itself. The amp was cold and the driver had been stored for over 6 months. It was breaking in! It got better, but of course there still wasn't any bass. Hornresp.exe suggested that with corner placement, there would be some bass, about 6-9 dB down. I pushed the horn into a corner and turned up the bass on my amp. Not quite an earthquake, but it you can follow the bassline well and the balance seems very natural. A rear chamber should help as well, but I couldn't be bothered anymore...

This is the largest horn I have built so far. Every time I build a bigger one, it sounds better. Clearer, cleaner, warmer, more open. The last one is strange, I expected longer and larger horns to be less open. Anyway, there is a very nice depth in the music now. I tried a few different recordings, ranging from computer-generated reggae to electric guitars and from acoustic pop to philharmonic classical. Most exciting was (for me) that this horn is really bad for French horns and really good for trombones. I play the trombone myself. ;-)

Building is fun. I should do more of it. I guess I can, now that I have rediscovered the very silent figure saw. :-) Let's see if I can build an even bigger horn, perhaps with bending ply this time.

Ivo

Tags:
0