I know this is heresy, but...

Undertow,

The more harmonics in music the less sensitive it will be to room modes (if you excite several modes at once an uneven response at a particular frequency becomes less obtrusive). An instrument without harmonics is not much use....it won't sound good at all. Tube amps on electric guitar throw out loads of harmonics and give the guitar a very rich sound even when distorting a sound that is good in all kinds of venues due to the richness in harmonics.

Analog generally has higher harmonic distortion content than digital, especially in the LF, it is possible that a good analog system will therefore play better in a room than digital. The same can be said of Tube amps...the added harmonics can help even things out a little ( our brains perceive a combination of the fundamental and related partials not single frequencies ).

Digital, with the least harmonic content, is less forgiving on the room, IMHO. So I would agree with your comment. Digital will also sound "thinner", particularly in the bass.

Undertow and Warnerwh,

How much acoustic panel treatments did you need to add before you noticed an improvement in the bass? Square footage or linear feet of bass trap? What do you recommend if you desperately want to minimize the amount of ugly panels covering walls. What is most effective in a corner...a Mondo trap from Realtraps?

So you may be best just going after the most Bass trapping possible with aesthetic appeal you can in that room and hope for results with your subs

My thoughts exactly. Big rooms are generally better than smaller rooms but they can suffer from very long reverb times in the bass (end to end). Currently a PEQ has all the room modes well under control but my thinking is that it might be better (more natural sounding) to do more with bass traps on the rear wall to dampen long reverb (about 10 feet behind the listening position). I am struggling whether it will really do much to improve the extreme LF?

FYI: I am generally very skeptical of tweaks but following advice on a Genelec website lead me to be pleasantly surprised. The other thing that convinced me was Doug Sax Studio. Doug won a life long achievement award from AES for his work on audiophile recordings (Sheffield labs etc.) and he built this studio in 2004 with soffit mounted speakers in a half wall.

Shadorne...Rives audio, who certainly are great believers in room treatments, will tell you that low frequency problems can't be fixed this way.

The above comment is my worry exactly...I am sure acoustic treatment is essential and extremely beneficial in a smaller room ....but is it effective in a larger room for below 100 Hz? I don't use a PARC but I have a Behringer PEQ controlling or taming the Sub (reducing room modes). On the mains I use some slight bass shelving (about 3 db) to reduce the bass boost effect from the soffit mount. I don't have much concerns in the mid/tweeter range as all the walls have a roughened surface (about 3 to 4 mm deep) which helps with diffusion, furthermore, the speakers are placed well away from side walls (about 4 feet away, so side reflections are delayed about 8 msec which is almost certainly enough not to interfere with primary signal, using the 5 msec rule of thumb for side reflection and diffraction)

Shadorne, you can look at my new system pics I added 16 linear feet of trapping just hours ago, and I am updating the pics right now.

Wow nice set up - your room looks awesome and I bet it will sound great too once you have it all setup.

I appreciate all the ideas and admire/respect what you guys have done.

You may want to contact Rives or Realtraps. If you buy something from them they'll be very open to advice for you.

Warnerwh, I think that is a good plan but once I take that step I will find myself committed. That is whay I like Audiogon forums...it takes me years to make a change or a decision. I am not a compulsive tweaker and tend to approach everything from an engineering perspective. This is why your advice is so important to me before taking any steps. Unlike many on these forums, once I settle on something, I will likely stick to it for a minimum of 10 years or more.