Hi all,
I'll start my first post here with a small project I've recently finished. I've stumbled upon these small to medium sized cabinets from IMF, heard them a little bit over an expensive setup and got convinced I've got to take them home. The speakers were in very good condition but the cabinets were not, due to age and improper caring. I've decided to try something bold for me (as my wood working skills are very modest): redo the veneers on the cabinets and the missing wood parts and then spray lacquer/varnish on them.
The cabinets are 480 x 255 x 275 mm wide, featuring a 200 mm bass/mid laminated cone and a 25 mm soft dome tweeter. Crossover frequency is stated at 3 kHz, with a frequency response stated from 60 Hz to beyond audibility. They weight aprox. 14 kg.
The original brochure advertised them as finished in a high quality American walnut, so I ordered the same type wood veneer from a great DIY shop a few hundred kilometers away. I've decided to recap them also with some new decent quality capacitors. The original capacitors were electrolytic non-polarised ones. They seemed to have a 10% tolerance. I could not test them extensively, just a quick check on a digital capacitance meter. Some showed under 10%, some a little bit over 10%.
The process started with removing everything from the cabinets - logos, speakers, terminals, filters. I started then clearing the veneer from the cabinets. A water soaked towel will help removing the veneers, which is a hard job. Although they seem damaged and old, they are well glued. After that, I had to repair minor holes I've made and the corners. After that, I started gluing the new veneer sides one at a time - kept each side with 20 kg on top for 24 hours. One of the mistakes I did was that I didn't flatten the veneer that was more or less wavy on some parts. I thought that gluing and the weight over will flatten it. Couldn't be more wrong. However, a clothes iron or heat gun can help with that if you mistake like me, but won't repair the mistake 100%. If possible, the most important advice is to take somewhere the veneer and have it cut professionally for each side and edge. I didn't and it can be easily seen.
After finishing with all the veneer and repairs, I've painted over a ground coat. Left it for 24 hours, then sprayed two times with clear varnish, again 24 hours between. After that, remounted the filters, logos, speakers etc.
They sound quite clear and neutral. The bass is unexpectedly sufficient. There were some sections in a few songs crowded with instruments, voice and deep low bass altogether and I could feel that the bass unit was a little bit confused and muddied a bit the sound. Still, nothing to object to this vintage 20 cm mid-bass unit. I will not compare them to certain speakers, but I could say they could be placed in a 1500-2000 euro studio monitors range.
Alas, I wish I knew better on how to restore and cut them more properly. For who has them, the filter schematics (attached below) may come in handy.
Cheers!
First four pictures, original cabinets and filters:
Old capacitors, new ones and one finished filter:
Cabinets restoration:
Filter schematics:
I'll start my first post here with a small project I've recently finished. I've stumbled upon these small to medium sized cabinets from IMF, heard them a little bit over an expensive setup and got convinced I've got to take them home. The speakers were in very good condition but the cabinets were not, due to age and improper caring. I've decided to try something bold for me (as my wood working skills are very modest): redo the veneers on the cabinets and the missing wood parts and then spray lacquer/varnish on them.
The cabinets are 480 x 255 x 275 mm wide, featuring a 200 mm bass/mid laminated cone and a 25 mm soft dome tweeter. Crossover frequency is stated at 3 kHz, with a frequency response stated from 60 Hz to beyond audibility. They weight aprox. 14 kg.
The original brochure advertised them as finished in a high quality American walnut, so I ordered the same type wood veneer from a great DIY shop a few hundred kilometers away. I've decided to recap them also with some new decent quality capacitors. The original capacitors were electrolytic non-polarised ones. They seemed to have a 10% tolerance. I could not test them extensively, just a quick check on a digital capacitance meter. Some showed under 10%, some a little bit over 10%.
The process started with removing everything from the cabinets - logos, speakers, terminals, filters. I started then clearing the veneer from the cabinets. A water soaked towel will help removing the veneers, which is a hard job. Although they seem damaged and old, they are well glued. After that, I had to repair minor holes I've made and the corners. After that, I started gluing the new veneer sides one at a time - kept each side with 20 kg on top for 24 hours. One of the mistakes I did was that I didn't flatten the veneer that was more or less wavy on some parts. I thought that gluing and the weight over will flatten it. Couldn't be more wrong. However, a clothes iron or heat gun can help with that if you mistake like me, but won't repair the mistake 100%. If possible, the most important advice is to take somewhere the veneer and have it cut professionally for each side and edge. I didn't and it can be easily seen.
After finishing with all the veneer and repairs, I've painted over a ground coat. Left it for 24 hours, then sprayed two times with clear varnish, again 24 hours between. After that, remounted the filters, logos, speakers etc.
They sound quite clear and neutral. The bass is unexpectedly sufficient. There were some sections in a few songs crowded with instruments, voice and deep low bass altogether and I could feel that the bass unit was a little bit confused and muddied a bit the sound. Still, nothing to object to this vintage 20 cm mid-bass unit. I will not compare them to certain speakers, but I could say they could be placed in a 1500-2000 euro studio monitors range.
Alas, I wish I knew better on how to restore and cut them more properly. For who has them, the filter schematics (attached below) may come in handy.
Cheers!
First four pictures, original cabinets and filters:
Old capacitors, new ones and one finished filter:
Cabinets restoration:
Filter schematics:
