Thanks Galu.
First I tried the .53mH Inductor. It heavily muted the upper frequency.
I then used the 0.23mH Inductor.
The result: More bass, muted the high frequencies a tad, removing the ear piercing top, but remaining acceptable. A little more volume was required to achieve the same loudness. Although a little less on the high frequency, it now has a more balanced sound. I suspect an air core Inductor would be better again, but I'm trying to keep a lid on costs.
A nice pair of Loudspeakers for the garage, and, in many respects, superior to contemporary offerings sold at silly prices for what you get.I wired up the DM110s to a creaking old CD receiver which I use in my Man Shed for background listening to CDs or radio while I am hobbying. The speakers sound good in that role, and I have no urge to play around with the crossover components!
I like to reserve my main system for serious and attentive listening, as well as avoiding unnecessary wear and tear of my thermionic valves!
It seems my estimate of using a standard inductor value of 0.22 mH was on the ball - just enough to increase the Blackcone's HF roll off a tad and not stray too far from the original designer's intention.
P.S. I see people trying to sell DM110s for £150 and I admire their optimism. "Nice for the garage" as you say, but zero DAF (Domestic Acceptance Factor)!
P.S. I see people trying to sell DM110s for £150 and I admire their optimism. "Nice for the garage" as you say, but zero DAF (Domestic Acceptance Factor)!
After the initial test on one of the enclosures (to allow for before and after comparison) I duplicated the change on the second speaker and hooked them up for more testing.
I played three tracks from various CD's and I was very satisfied.
Sadly, after a further hour of play the sound had deteriorated.
The shrill and overly sharp high end returned.
I have to do more testing but it seems either the tweeters or all drivers aren't up to any extended use??
It looks like you may have taken this renovation as far as you can.
At the right of the attachment, you can see the low pass filter Troels designed for his SEAS 21TV-G drivers.
Unfortunately, without acquiring the simulation talents of Troels, you can't be sure which component values would suit your Blackcones.
At the right of the attachment, you can see the low pass filter Troels designed for his SEAS 21TV-G drivers.
Unfortunately, without acquiring the simulation talents of Troels, you can't be sure which component values would suit your Blackcones.
