2. speakers
  3. 1211302926

Just Purchased Infinity RS2B / RSIIb owned RS 2.5

FYI Infinity Fans:
I have lusted after some RS2bs for 20 years after loveing my 2.5s. I thought the 2bs would fill in the middle and keep all of the strengths of the 2.5s. In reading the manual, I was unaware that the 2bs had a bass equilizer (not crossover) that was NOT optional. The bass equilizer has been lost. I hooked up my VTL compact 100s with several preamps & the sound was mud in the bass and boring in the emims/emits. One of the emits is even covered 50 percent, the top one in the front. These 2bs sound like monster cable . . . go figure. Monster cable was used in the speakers. Also, it turns out that ONLY the middle emim is hooked to the midrange control. The middle emim is the only one that sounds like the emims in the 2.5...they are running full out. The top and bottom emim are subdued and they are trying to mimic a good dome midrange....yes the lower vocals are better but who cares?? I have lost the magic of the emims. I have had some Infinity Sigmas in my room and one super emim did a better job than these three emims. Last night I hooked up a couple of transitor amps and the sound was MUCH improved... remember what older monster cable did to good solid state stuff? in the 80s. I guess I'm going to stay with threshold but I own several good tube amps that I love to hear the imaging etc etc. I might be nuts but the improvement I have gained with Kimber Kable 4TC and Audioquest jaguar interconects is lost in the old monster cable wire?? I am probably being to hard on these speakers, but I remember a german saying the 4.5s were the best of that vintage. How are the emims controled in the RS1bs?? are they all hooked to the crossover controls?? To be continued. Thanks for reading. Larry
apfdirtdoctor
nsgarch's avatar
nsgarch
2,524 posts
 
Marchand Electronics has been around as long as I can remember (we're talkin' half a century!) and it wouldn't surprise me to learn that Infinity "borrowed" their equalizer from this unit, although in a "watered-down" version. Come to think of it, Marchand produces many, many OEM components, and quite possibly made the bass EQ unit for Infinity! Look here:
http://www.marchandelec.com/wm8.html
And check out their other stuff -- they're a rock solid, straight up, Amerikan company!! Y'know what I'm talkin' about?!
.
ait
480 posts
 
Well I un-watered-down my unit (I guess that would be "concentrating" it). Mine now has all metal foil and metal film resistors, high speed OPA827 opamps, and high quality PP, PS and copper foil/PIO caps. I also moved the power supply and the output circuits off the main EQ board to reduce interference, upgraded the capacitor filter to a CRC, added Bybee Music Rails DC power conditioners to both the + and - power supplies, inserted a TI-shield shield between the noisy power supply section and the rest of the unit, and built a directly DC-coupled output curcuit using very low DC-offset opamps to replace the stock MOSFETs. I also replaced a couple of the resistors with cermet pots so that I could tailor the response curves to be different for each channel to suit my room.

Here's what the inside of the unit looks like now:

Modified LF EQ Unit
apfdirtdoctor OP
36 posts
 
Guys, thank you for your thoughts and input. Muzakk, I couldn't agree more that the higher and lower mids are wired to limit high frequency on the RSIIBs. I guess I got addicted to the beaming midrange of the 2.5s. I thought it was detail. To me this affect dulls the sound with my expensive tube amps and I find myself hooking up a transistor amp to offset this sound. I wonder if Infinity was using Threshold when they were working on these speakers. It seems to be a good match, but I loose the "openness" of a good tube amp. Also, the 10 inch woofers have a hooded sound to me. I miss the watkins 12 inch sound of the 2.5s and 4.5s. I know they were trying to fill in the middle with the RSIIs, but I lost the magic of the older speakers (upper midrange) . Also, I agree the bass EQ is doing alot to alter the frequency response and I am currently using the EQ for the RSIIa which is a much less complicated circuit than the EQ for the RSIIb. It is possible the EQ for the RSIIb is not working as it should. I am still amazed at people that do not realize what the EQ box is doing?? Thanks again. Larry

PS for my fun back-up speaker system I put some 12 inch polypropelene (20-400HZ) infinity car subwoofers in some Dahlquist DQ10s and then I added a Heil midrange/tweeter driver to replace the dome and piezo tweeters....sorry I understand it sounds crazy but I love the sound of these speakers with tube equipment.
apfdirtdoctor OP
36 posts
 
Update Feb 2014:
I moved to a different house and put the RSIIbs on the tile floor versus sitting 12 inches up on on a large fireplace hearth at the old house. WOW!!! what a difference 12 inches makes....now I am sitting on the couch staring at the middle EMIM on the RSIIB and the midrange and highs are to die for.... no more "hooded" sound from vocals out of 10 woofer and lower EMIM. At the old house when I was sitting, ear level was between the top woofer and lower EMIM. The 2.5s sound very similar at either location....two beaming EMIMs ??? I am having fun listening to the IIbs...like this is the first time I have given them a chance...love playing with different amps and tube types. Larry
ait
480 posts
 
If you really want to go crazy, check out the new EMIM ribbons offered by Apogee Acoustics. They fit in the standard EMIM shell and are a HUGE upgrade in sound quality over the originals.

Graz at Apogee makes them in batches of 90, about once or twice per year. You have to get on the list and when he has enough pre-orders he makes a batch. The build quality is stellar. Here's a link to his Infinity forum:

New EMIM Ribbons

.
More to discover