Thiel Owners

Tom, my listening room is nowhere as magnificent as the other room you are commenting on. My listening room is a family room off the kitchen and unfortunately has an open doorway a few feet in front of speaker and 8 ft to the side going to the living room with the rear remainder being open to the kitchen with a 3 ft high wood cabinet granite top seating area. The other walls are enclosed. Room is 20 ft wide with speakers 1 ft from back wall and centered on wall 6 ft apart. The depth of the room is 18 ft and I am sitting 11 ft from the speakers. I know I am violating the equilateral triangle rule. I need to rearrange wall and  move speakers a little further apart 8 ft and move closer to speakers 9 ft. Typical ceiling height of 7.5 ft and is a popcorn finish. The walls are wood paneling over studs with no drywall or plasterboard underneath. Flooring is ceramic tile and there are NO acoustic treatments. I thought my tweeters went bad, not the case, I tried different speakers and amplifier.  Thiels are not the problem.  I think I have the worst listening room parameters. Maybe an area rug in front of speakers to begin.  The kitchen is 14 x 12 ft. Does this space also get counted in overall area since the sound energy is mostly unobstructed to this area. You may have to read this more than once, but I wanted to paint a complete picture, without actually sending a picture. I'm also interested in comments from anyone about Parasound 2125 V 2 since I like on off trigger and would rather buy new. Thanks for your comments.

barnett - a couple of thoughts about CS2.2s in your room.

The room is wonderfully designed. Congratulations on however you got there. The dimensions are right in the middle of the Bolt Pattern which allows for leeway regarding the contribution of your diffusion panels on the side walls. Also the Bonello Modes stack up very nicely with increasing density per third-octave frequency rise. All good for a musical-sounding space from most anywhere in it.

The picture gets murkier when considering bass, and especially adding a subwoofer. Many of your bass modes fall on whole-notes and intervals which will be accentuated and long-lasting when stimulated. Specifically you have reinforcement modes at 24, 33, 41, 49 Hz (rounded) which fall on notes at A=440Hz. By the way, they fall off-note as the room width acts smaller than 17’. It’s hard to predict exactly how your diffusers affect the functional width of the room.

These modes will definitely be made more troublesome by adding subwoofer(s) bass extension. Those will not be very responsive to equalization. So consider tunable absorption devices to address those issues.

A word about the CS2.2. Bass runs out of steam with a hard ’splat’ when driven hard with bass content. John Atkinson proclaimed in his initial review that the passive radiator and/or woofer was bottoming. He bought and used CS2.2s personally for a few years until the bass problem got the better of him. He is a bass guitarist after all. That speculation turns out to be false. The problem is real, but it fixed itself when I took the crossovers outboard for redevelopment. That ’splat’ is part of an overall veil-shimmer-overload that is part of the CS2.2. It goes away (quite gloriously) with EMF management. If outboarding crossovers is too much, I’m also working on a set of inboard solutions centering on moving the crossover(s) from behind the woofer to the bottom of the cabinet (where they should have been all along.)

Plenty to chew on here. Have fun.

Tom

audio1326 - we live with what rooms we have.

Complex geometry with openings into other rooms are challenging. My previous studio (shown on my virtual system photos) was such a room. L-shaped in the corner of a 30x48' second floor with bleed to both the 54x48' area below and attic space above. I don't have Finite Element Analysis in my toolbox, so I worked it throughout a year (or more) to excellent results. I can answer specific questions from that experience among others. You will be the best judge going forward - it would be daunting for anyone else to offer opinions on such a complex space.

Point of caution (information) regarding the GFA amps. The original 535, 545, 555 are Nelson Pass, high current, etc. etc. The next generation (series II) are not. They only share the case and name. They are well-considered and sometimes preferred, but note they are similar in name only. One reason I chose the original 555 is because Jim Williams / Audio Upgrades does such great upgrade(s) for very reasonable cost.

I found a 555 and a 545 already updated that I am looking at. I prefer to not hassle with shipping such a heavy amp for the mods. Do you feel that the 545 is enough, I checked my db meter and 75 to 85 with 95 db peaks is what I measured. I like the trigger on-off of newer amps. I found the Parasound 2125 v2 with 235 watts into 4 ohms and 35 amps current delivery on-sale for $829 which buyers compared to the older Adcom, but said they preferred the Parasound. Only problem is no one was using them with Thiel speakers. Any thoughts on getting new Parasound instead of 35 year old Adcom? I will check with my electrician about a dedicated line or 2 since I think my utility room, porch outlets and part of kitchen share same breaker. Thanks for looking at this on a late Saturday night and getting back to me.

I can't comment on which amp would best fit your circumstances and orientation. And I don't know the Parasound. I would always go for the larger Adcom. I will have two 555s, they bridge nicely. You do want a dedicated Audio circuit, and upsize the feed wire while you're at it.