I spent some time listening and tweaking the rig over the weekend. Installing the new tweeters in the RM30s gave me an excuse to retune the speaker to the room. BTW, the CDWGs that I mentioned reinstalling in my last post didn’t last 24 hours. While I’m impressed with the increased horizontal dispersion, I still hear a muffled constriction in the midrange that I just can’t live with. So back to closet they go until next year’s attempt to make them work.
First, a disclaimer. My system is both a listening oasis and a laboratory for mad scientist audio experiments. Nothing I mention here has been approved or condoned by Brian Cheney or VMPS. I do this stuff fully aware of the risks and rewards of modifying and manipulating the commercial products that find their way into my listening room.
That said, a quick note on my RM30 setup. I bi-amp (tri-amp if you count the stereo subs) the RM30s with 50 watt Quicksilver monoblocks on the mid-highs and 100 watt VTL monoblocks on the woofers. The only crossover parts left in the speakers are the midpanel low pass filter coils and the tweeter level pots and high pass filters. I run the mid panels wide open with only a line level 400 hz 1st order high pass filter on the inputs of the Quicksilver amps. I find this to be much more transparent sounding than the internal TRT’d crossover. I also removed the woofer’s low pass coil.
For the woofer and subwoofer filters, I use a miniDSP 2 way digital crossover/parametric EQ unit (
www.miniDSP.com). With miniDSP I can set and manipulate XO points/slopes, phase, level, and parametric filters on the fly from my laptop. For less than $200, this is an amazing product. It’s not transparent enough for me in the mid-highs (I have yet to hear a DSP that is), but with latency in the 2ms range, I can control the woofers & subs and blend them seamlessly with the mid-highs.
Using REW’s 48th octave RTA and pink noise I repositioned the speakers’ sidewall/backwall position for the smoothest response between 60 and 300 hz. While I mostly voice speaker placement by ear with music, this is one area where room measurement really helps. After a few tweaks to crossover frequencies and levels, the bass now snaps and energizes the room with minimal boundary induced overhang. Surprisingly, I only used one parametric filter per channel (6db cut @160 hz).
I have the speakers towed in so they cross 1 foot in front on me as this seems to optimize the midpanels’ horizontal dispersion for a wide, coherent soundstage. I also found that I can tailor the balance of midrange energy by tilting the speaker up in front to adjust the midpanel’s vertical dispersion. So using blocks and tiptoes, the speakers are tipped up about 4” in front. I’m still experimenting with tweeter level but I think I’m in the ballpark between 10 and 12 o’clock on the potentiometer. That may change as the new tweeters settle in.
All that to say with the new tweeters in and the newly tuned setup, the speakers really are sounding magnificent.
Russ
Edit: I fixed the miniDSP link.
