The forward-firing full range CR125S drivers produce the full frequency spectrum without the treble peaks and other artifacts often heard with Fostex and Lowther drivers, along with surprisingly deep bass for a 4.5" driver. The drivers are only 86dB sensitivity, and the front and rear drivers are wired in parallel resulting in a four ohm load, so they are not intended for use with low powered tube SET amplfiers. The 40W/ch Monarchy class A zero feedback solid state amp I'm using to break them appears to be a good match.

• Bipole Single Driver Speakers

I like the way those new speakers look. Let us hear how they sound after a few days of break-in. I'm glad that you built those jewels.

Jim

I did play them for about 12 hours before disassembly, and my initial impression afer the 12 hours is this: The bass is amazingly good for a speaker with two 4.5" drivers as long as you don't over drive them. The midrange is about what I would expect from a 4.5" driver that costs $70. It's as good as the $100+ Vifa XT's in my line arrays. The treble is the only shortcoming I can hear at this point. According to the manufacturer's freq resp graph it should be flat to about 10khz, then drop to about -5dB at 15khz, then return to flat at about 20khz. I definitely hear a drop above 10khz, and it sound to me line it begins somwhere below 10khz. I miss the crispness of cymbals, etc. that I'm accustomed to hearing from speakers with a good quality tweeters. (Yes, I did verify I had installed the FR drivers in front and the WR drivers in back, and not vice-versa).

I'm the ultimate cable agnostic, but I'll admit some speaker cables and internal hookup wires are brighter than others. The brightest I have heard was made from silver plated teflon coated stranded copper wire. I have some in the parts bin, and I've assembled some new harnesses to replace the stock copper internal wire than came with the kit. We'll have to see if this has any effect on the treble.

The soundstage isn't quite as focused as my non-bipole speakers, but it's actually more realistic - more like the soundstage I'm accustomed to hearing at live events. I was at a blues club Friday nite and listened carefully to the live event soundstage. I couldn't identify exactly where each performer was like I can with the overhyped soundstage of the typical pair of minimonitors. The greater ambience these speakers offer is especially nice with recordings of live popular/jazz events or classical music recorded in the typical reverberant concert hall.

Thanks for the update on your speakers. I agree that the bass is very good for these little drivers within limits but they aren't capable of pro sound output levels.

My on-axis measured data shows performance within a 5 dB (that is + 2.5/-2.5 dB) window between 1000 Hz and above 20,000 Hz. That is exceptional for an inexpensive full range driver. Off axis the treble beams a bit as you would expect. Of course you don't have quite the sparkle that a quality tweeter would convey. I can send you a copy of my measured data if you wish.

On my speakers I used a single run of Canare 4S8 wire (4 16 awg copper conductors) to connect between the terminal plate and the drivers.

The bipolar nature of these speakers do add a bit of ambience that will disturb the purist who wishes to have a small sweet spot. As you suggest they project much like live music versus sounding like speakers.

Again thanks and I appreciate your efforts.

Jim

Perhaps he tried this one: "But honey they only take up as much floor space as a mini-monitor."

Jim