Peter Gunn's room tweak report
& other observations


    The following is an attempt to put down some recent experiences with room treatments and gear with the hope someone else may benefit.   It is long-ish (soon to be a novelette) but hopefully of use, and even includes a pic.   The room in question belongs to my audio friend, but he is too lazy to report on this himself.

    First, the room: Start from scratch 13' square room solely for audio use.

    Second, the gear:

Pre ~ Conrad Johnson PV-8
Amp ~ Rogue 88
Player ~ Ah! Njoe Tjoeb 4000 + 24 bit upsampler and NOS tubes
Cable ~ Zu Julian
Rack ~ Target
Phono ~ AR ES1
Speakers ~ Magnepan I's (late 70's) upgraded with new drivers, upgraded caps and XO, Cardas wiring and tiffany binding posts. (He got them this way and they cost him $375, a genuine steal)

    His biggest problem initially with the room was that it was square (13') and square rooms are an acoustic nightmare, especially with dipolars like Maggies.   This one was no exception.   A number of options were considered, but since he hated the ficus route and owing to the fact we both had watched TOO much trading spaces lately, we decided to try a back wall of home made panels.

    Materials were ½" plywood cut into 45 one-foot squares, upholstered with one and a half yards (each) of 3 shades of vinyl material (black, white and blue/grey) and batting.   The wood he got free from work scraps, the vinyl cost $25 and the batting $2.50, both from a fabric store.   Total cost $27.50.

    Construction was simple but very tedious (especially as I did it for him) The sheets of plywood were cut to size and a hole drilled to accept a nail, batting was laid over them which exceeded them by about ¼" per side and the vinyl was cut 1and ¼" inches larger per side.   Materials were stretched slightly and stapled to the backs like regular upholstery.   I used a power stapler, and STRONGLY recommend one. (aprox. 30 staples per block at 45 blocks was 1,350 staples.   A death sentence with a hand stapler)

    They turned out nice with slightly bulged faces and some cushion.   They were hung on the drilled holes with box nails (I don't trust 2 sided tape) with a space of about ½" between them, 9 across at the top in an inverted U shape going 6 down.   The final product was this...

    Yes, the tank sitting there is not a Rogue.   (it can be seen bottom left)   It's my Pass Labs X250 and it wouldn't even fit in the rack.   More on that later.

    Bass response went thru the roof after this mod.   Also improved was the overall imaging as well as the "sound" of the room.   The slight echo was gone as well as a "brittle" quality and everything got better and more focused.   He was quite happy, and his setup never sounded better.   The open space was left above the rack as a Target wall shelf is going in for the turntable.

    Ideal speakers placement was canted toward the sweet spot, the inner (back) edges being 22.5" from the rear wall and the outer edges 25" from the side walls.   This yielded the best results by far.   Further out they lost definition and slam.

    FYI room lighting is by IKEA.   Overhead is one of those halogen spotlight systems that run off the wires they hang on, and in the corner was put round floorstanding Chinese paper lights to kill the corner reflections and they work great at this while providing nice, ambient lighting.   The carpet was a lucky (cheap) remnant find at an outlet.   Seating is a black leather sofa opposite the rig.   It's all very star trek mod.

    The problem was that shortly after he did this, he put a 24-bit upsampler in his Ah! player along with NOS Siemens tubes, upgraded his cable and put everything on the new Target rack plus a few other odd tweaks.   Misery ensued however, as the resulting detail improvement became such that his Rogue 88 amp, which up till then drove the speakers fine, now drove the Maggies like they had wool socks over them.   It couldn't resolve the load anymore and was choking on all the new detail.

    Fit to be tied does not describe his demeanor.

    A week or so later, my recent purchased arrived, a Pass Labs X250 amp.   My gear is in the living room awaiting the new room I am going to build and it is a shambles to accommodate the wife so I had no place for it.   I decided to cart it over to his place and hook it up "for the hell of it", but mostly as I wanted to hear it.

    Wow, did that thing light those Maggies up.   What an incredible, musical amp!   I knew the Maggies were capable of sounding good with all the upgrading done to them, but even I was amazed at how good they sounded.   It also brought out just how good the wall tweak is.   The soundstage is huge with the Pass, and it all sounded just right with great bass extension and pinpoint imaging.   Grabbed those Maggies and they obeyed every command.   It has been my party spot since I did it, just high-end heaven.

    In fact, he had up to this point always had the tweeters inboard due to the smaller room size, but with the Pass they threw such a huge soundstage they sounded better with the tweeters out.   It was startling to hear, and the first time I'd seen Maggies pull that off in a smaller room.

    So that's his double-edged sword.   He's thrilled that he knows how good it can sound. He's mad that he can't afford the amp to make it sound that way.   His remedy is going to be to box the Maggies for the time being, as he's getting a pair of used Linn Keilidhs with the improved tweeters, so he'll live with the Rogue for now.

    I would never have expected the Rogue to do what the Pass did, but I am surprised at how power hungry even these older (but tweaked) I's could be.   Still, I was expecting a bit more from the Rogue.   With a load it can handle it had sounded good in the past.

    As for the wall, it could not have worked better and if you like the look and have the time and ability to do it I think it will reward you more than most other treatments will.   I was never much for the ficus route if solely for the reason they are dust traps, and at best they break up waves.   They could not add the punch this wall did.   I would expect it to benefit almost any room.

    The Moral?   No amp is too big for your Maggies.   They are truly the brawny towel of the speaker world, as they just keep soaking it up.   And don't discount the old I's.   With all the upgrades and a high power class A amp and tube front end they sound gorgeous.

    Thanks for making it to the end and I hope it was of use.