Aerial Accoustics 10ts:
https://www.stereophile.com/content/aerial-acoustics-10t-loudspeaker-measurements
https://www.stereophile.com/content/aerial-acoustics-10t-loudspeaker-measurements
I was able to pick up a pair of IMF Electronics CM2 (Compact Monitor 2) loudspeakers a few years ago for an inexpensive price. These are a 50 year old pair of modest size bookshelf/stand-mount speakers that are a 2-Way with an 8 inch woofer and a soft dome tweeter. The speakers were working and the drivers were fine so I renovated them by pulling the woofers and then the crossover networks, and replacing all of the capacitors with matched replacements from Falcon Acoustics in the UK. Even though the woofer voice coils were not rubbing I inverted the woofers when I re-installed them - to offset 50 years of gravity on the suspensions and spiders. I also refinished the walnut veneer with a couple of coats of Tung Oil Finish. They are a resistive aperiodic bass reflex design and sound very good.
The closest contemporary speaker to these would be the Harbeth 30 which are the same size cabinet with the same size drivers, but with a high Q tuned port for the bass reflex tuning. I prefer the way the IMF CM2 sound, as they have smoother midbass response to my ear.
My CM2's which I bought in the early 80's are still working fine, the only thing I've replaced being the brown foam front covers and black foam at the bottom of the speakers, both of which eventually fell apart. However, the veneer on top of the cabinets could do with refinishing, so I wondered what you might recommend prior to applying Tung Oil Finish.I was able to pick up a pair of IMF Electronics CM2 (Compact Monitor 2) loudspeakers a few years ago for an inexpensive price. These are a 50 year old pair of modest size bookshelf/stand-mount speakers that are a 2-Way with an 8 inch woofer and a soft dome tweeter. The speakers were working and the drivers were fine so I renovated them by pulling the woofers and then the crossover networks, and replacing all of the capacitors with matched replacements from Falcon Acoustics in the UK. Even though the woofer voice coils were not rubbing I inverted the woofers when I re-installed them - to offset 50 years of gravity on the suspensions and spiders. I also refinished the walnut veneer with a couple of coats of Tung Oil Finish. They are a resistive aperiodic bass reflex design and sound very good.
The closest contemporary speaker to these would be the Harbeth 30 which are the same size cabinet with the same size drivers, but with a high Q tuned port for the bass reflex tuning. I prefer the way the IMF CM2 sound, as they have smoother midbass response to my ear.
My CM2's which I bought in the early 80's are still working fine, the only thing I've replaced being the brown foam front covers and black foam at the bottom of the speakers, both of which eventually fell apart. However, the veneer on top of the cabinets could do with refinishing, so I wondered what you might recommend prior to applying Tung Oil Finish.
Thanks for that comprehensive feedback. Fortunately, my cabinets have not suffered much in the way of veneer chips. The six circular velcro fasteners are fine and do a good job of holding the new acoustic grill foam covers I bought from Speakerbits in Melbourne. I just wonder whether the Tung Oil Finish will provide a uniform appearance to the tops of the speakers or whether I need to use coloured wax beforehand? Thanks also for the tip regarding recapping of the crossovers.Hello! My cabinets had a few veneer chips on the lower edge that sticks out and a bunch of white scrapes where it looked like someone carrying them brushed against a white painted hallway. The biggest defect was that most of the circular hook fasteners for that old grill foam were still stuck on the cabinet fronts, and those fasteners that had fallen off left a hardened glue residue behind. I was able to find the new replacement black open cell foam I used that's only about 3/8 inch thick to install in front of the dense ugly green foam at a tropical fish supply house for use in aquatic filters. I used Isopropyl Alcohol on 3M Scotchbrite fine grit pads, brushing with the grain to get off everything except those dots of hard glue from the hook discs. For those I laid the speaker cabinets on their back and kept wetting the glue with Alcohol until it finally relented its grip and let me scrape it off with a plastic chisel looking tool for removing emblems from cars - bought from an automobile refinishing supply catalog. However you could easily make one by cutting down a plastic ice scraper to 1 inch wide and using a file to apply a chisel point to it. Alcohol and those two mechanical approaches got all of the junk off, plus the 3M pads acted like a very fine sandpaper. The next day I applied a coat of Tung Oil finish, and a second coat the following day. Last step for the veneer chips: I filled them with a Minwax scratch crayon/pencil that was the correct tone - it's basically a colored wax pencil you can buy at a paint store and use like a crayon. The re-finishing job has held up and they still look and sound nice today!
I would recommend recapping the crossovers as the caps are available inexpensively in a set from Jerry at Falcon Acoustics in the UK. He matches them and it's easy enough to remove the circuit boards which are held in place by tye-wraps that can be cut to release the boards and then replaced upon re-installation. These were meant to be serviceable. I have heard of old caps exploding, and certainly my old caps had drifted in capacitance value.
Thanks for that comprehensive feedback. Fortunately, my cabinets have not suffered much in the way of veneer chips. The six circular velcro fasteners are fine and do a good job of holding the new acoustic grill foam covers I bought from Speakerbits in Melbourne. I just wonder whether the Tung Oil Finish will provide a uniform appearance to the tops of the speakers or whether I need to use coloured wax beforehand? Thanks also for the tip regarding recapping of the crossovers.
I haven't been able to find measurements of the Energy Connoisseur C-4. Perhaps this speaker wouldn't be quite as smooth as some of the others in the series (large mid-woofer). But here's a pair on Craigslist in the Boston area if anyone wants to spend $120 to find out:Energy Connoisseur series speakers, the ones with single-digit numbers, not the more recent ones with triple digits.
https://www.stereophile.com/content/energy-connoisseur-c-2-loudspeaker-measurements
http://www.soundstagenetwork.com/revequip/energy_c3.htm
https://www.soundstagenetwork.com/measurements/energy_connoisseur_c3/
http://www.soundstagenetwork.com/revequip/energy_c9.htm
https://www.soundstagenetwork.com/measurements/energy_connoisseur_c9/
RC series: RC-10, etc: (Plus real wood veneer!)
http://www.soundstagenetwork.com/revequip/energy_rc10.htm
https://www.soundstagenetwork.com/measurements/energy_rc_10/
Lots of things by PSB, for instance:
http://www.soundstagenetwork.com/revequip/psb_image_t45.htm
https://www.soundstagenetwork.com/measurements/speakers/psb_image_t45/
Some NHT stuff, such as the Absolute Zero or Classic Three.