Speakers that can be placed close to the back wall


Downsizing and need ideas for speakers that can be placed close to the back wall. New room size 20' W x 15' L x 9' H. Have lots of power to drive the speakers.
seadogs1
REGA RS7/R7

see R7 review in STEREOTIMES #25

in http://www.stereotimes.com/speak022306.shtml

pertinent extracts:

" ...Like many speakers built for UK and European listening rooms, the R7’s can be placed near a rear wall without exaggerating the bass response..."

" ... 34-years’ experience in the audio world have taught me that the most common system building error is mismatching the speaker to the room. Place a mini-monitor in too large a room and you get the bass-shy “squawk box” syndrome. Far more common in the US is buying a speaker whose bass response is more than the room can handle, resulting in various manifestations of boom, thud, and rhinocerine mud-wallowing. It’s more than a simple matter of room dimensions and overall volume: wall and floor construction also play a crucial role. It’s been my general experience that if you can get clear and tight response down to 40 Hz in-room, stop and count your blessings. And think very hard about pursuing response into the bottom octave. One is more likely to screw up everything achieved in the musically useful range of 40 Hz and above. While my own reference speaker, the Sound Lab Dynastat, is flat to 20 Hz in my large basement listening room, the number of times I’ve absolutely needed that bottom octave for musical reasons in the last two years is zero. While the lowest range of the organ might be majestic in a large cathedral, mismatched bass-heavy speakers that literally shake the house on its foundations are more likely to induce vertigo and viscera displacement than aesthetic satisfaction. So how do you walk the line between bass-shy mini-monitors and elephantine bass heaviness in the “normal” room? Enter the new Rega R7 loudspeaker...."
Any Audio Note speaker, some Linn speakers, and Von Schweikert Audio VR-35 are designed specifically to placed close to the back wall. I have my Zu Def 4s close to the back wall and they sound great.
The most important factor in choosing a speaker that's going to live close to walls is how the bass is tuned. Walls/boundaries will boost bass, possibly by a large amount. If you have a typical QB3/flat bass tuning and put that speaker close to a wall, you'll end up with 6db or more bump in the bottom couple octaves ... end result is a thick, muddy sound.

The ideal tuning for near wall placement is an Extended Bass Shelf. Even sealed boxes aren't always ideal for near wall, and can suffer the same effect as I said above, because there's no way to replicate an EBS curve with a sealed enclosure.

Unfortuantely most manufacturers don't tell you what type of tuning they employ. Instead you have to rely on anecdotal evidence like "I have brand x close to a wall and it sounds great", or the manufacturer marketing speak without any explination of why.
Vapor1 A question: Do any of your speakers use the EXtended Bass Shelf? I thought that technique only used front ported designs? Could you explain more in detail? Thanks!