How far can room treatments solve boomy bass?

Ja2,

Quarter wave effects exist for all of those surfaces. The closer the surface, the stronger the cancellation (deeper null) and the higher in pitch that the first null will occur. In most cases, I suspect that the wall behind the speaker is the biggest culprit, but it will be room dependent. In a small room, like the OP's, you have less flexibility in addressing this via placement. Even in large rooms, you're still going to get audible cancellation until you can get more than 10' from the nearest wall. That's usually impracticle.

If you use in-wall, flush to the wall, or on wall speakers, the analysis changes, but that's not the case for the OP.

It is true that placement, treatments, etc can somtimes reduce the impact, and reduce the amount of parametric EQ required. However, I've never seen a case where EQ did not produce clearly audible improvement after those steps were taken. I'm not suggesting that anyone abandon treatments, careful positioning, etc. I'm simply stating that, below app. 100hz, EQ is the only tool that I've found effective.

My conclusion is based on listening, but it is very clearly supported by measurements.

Kijanki,

Good luck finding absorptive material that's effective below 100hz. I looked for years, tried many, and never found any that worked. If you find any panels that work, please let me know.

As to "boomy bass" and the room's reverberant signature....that can be a problem in some rooms. The 1/4 wave and related modal issues will almost certainly be a problem in every room. In every case I've addressed, the latter has been far more severe, but this is certainly room dependent and case by case.

Simple passive treatments can usually get the worst of the reverberance problems under control. Proper placement can reduce cancellation effects, particularly if you employ multiple subwoofer (ala Duke L's "swarm " system) or soffit your speakers. Neither is usually an acceptable solution for obvious practical reasons.

Unless you're willing to that route, only Parametric EQ will address the 1/4 wave and related modal issues in the bottom 2 1/2 octaves. In all 3 dedicated listening rooms that I've had and in both dedicated HT rooms that I've had, parametric EQ has made a VAST improvement in the quality of bass response after extensive room treatment. It was instantly audible and clearly measurable.

Reverberant issues are usually easier to deal with passively, and that's what I do. However, that still usually leaves crappy FR below 100ish hz. At least it does in every room that I've measured. In all cases in which I've employed EQ, the room were decent to begin with. In all cases, the sound was better after room treatment and far, far better after EQ.

I'm not sure where/if I ever implied that room treatment was bad, but I never intended to. I use Hemholtz devices and a variety of absorptive panels in my current room. Still, bass quality is IMO night and day better when Audyssey is in the loop. That doesn't mean "perfect", it means "night and day better"?

IMO

Marty

If you ask 10 people if a PARC is the key, i guess you get opinions that differ. YES, it is in the signal path all the time.
You can use a Bypass button to shut it off if you like to do so with older, less dynamic and bass heavy recordings.
The PARC is only an EQ, it is not an instrument that helps you read/measure the room.
For this, i suggest you buy XTZ - Room analyzer pro II.
http://www.xtz.se/uk/products/measurement-system/room-analyzer-ii-proT
It is probably among the cheaper of all these kits and many acoustical companies use this prog and some dealers of Rives Audio also use it as it is cheaper than BARE (Rives own kit).
ALL is included, just plug it in and run the sequence. You will find it easy to use. If you buy this kit you can do alot of measurements (from 15hz and beyond) or you can set it up as instructions say and you get data you can start off with and you can also leave it like "this". "This" data you get, is the frequency or frequencies + the Q-value and the level (+db) the mode/modes. When you have the data of both channels (you can measure both separately and set both channels independant), you just type them into the PARC.
You deduct the db peaks of the mode(s). You need not set it at flat (linear), if you don't wish to. You can fine tune the setting after what you like if you do not wish to use flat.
But, if you use for example Gic acoustic devices along with PARC, you can void flutter echo and "bass mumble". The more panels you use, the more damped it will be. Some may not like this, some do. That is why i suggest you use both XTZ RA pro II and Gik acoustics devices. The Room analyzer pro II is not at all much more expensive than the original Room analyzer, but it is delivered with a better microphone and has more features. With Gik devices and PARC, you can set up your system almost in any room and find a very good set up that you like. If you buy the most advanced acoustical devices, and the heavy large bass absorbers from ex.

http://www.performanceacousticslabs.com/PAL/Products-Acoustics_Listening_Rooms.html

Look at Varitune V6 and V4.
You'll notice these are large and heavy. They work, they really do, but you might need 2 or 4 or 6 or 8 units.
All pending on how much db and how many modes you'll need to rid (lower in db).
An EQ is a good choice due to the fact that it will help you get a less boomy sound without a need to use these bass absorbers.
The EQ does not boost, just deduct level. Not everything is for every one, but the benefits are surely larger than those on the negative side.
What you will notice, is that it is a larger difference in dynamics at your recordings. Not all people like near flat (linear) response. The PARC will only rid the mode(s).
The devices from for instance Gik, will help you tune the room byond modes. But as mentioned, for the most crude bass modes you will need the PARC.
When you have (if you will buy these things) all done, you probably will notice a significant change in the whole range you hear. Then you can start looking over cables, tweaks and/ or repositioning your speakers etc. This kit will make the soundfield more precise less prone to let the room interact as much.
What is so nice with for example Giks 242, 244 and Tritraps is that they are light in weight. The PARC is small and not heavy. It is not as filling the whole room with heavy bass absorbers and diffusors all over. Using only acoustical devices, is not always so easy to use everywhere (due to size, weight and wives, girlfriends).
This kit that i use, helps me to set up my system in both a small room and a large room.
I can listen to all sorts of music and i can change settings if i want to. I believe in my head and heart, if you could hear this for yourself and cope with what a full kit would do, you would find more benefits to it all and it makes sense.
I play loud, very loud at times. I have been through lots of equiptment way more cosly than my current system. But this gives an illusion of doing all genres without issues and at times it's like using headphones. Just much more exciting if you get what i mean. Ofcourse you can ask and ask again if you want. I understand if some things might be of consideration. After all, it took my years to get it through that this is the best way for me. I hope i am not to unclear!?

Real simple...small speakers are for small rooms...get some monitors for the moment until you refigure your current situation....I feel your pain...I have had sets of floorstanders over the years...and was never satisfied with the bass...boomy and slow....probably the case of too much speaker in a given room...or placement issues....

River251, for bass below 200hz try checking out the Cathedral Sound Panels. They are not absorption panels but instead work on the venturi principle which says that a gas moving through a small opening will speed up which in turn is related to pressure changes in the room from the woofers. To the drivers the room becomes effectively larger, acoustically. The frequency range of the panels is optimized by the size of the holes in the 11"x16"x2" panels that you install in the upper room corners. They control standing waves without rolling off the highs and are about 90 bucks each. I have not used them (I currently have the opposite problem you do, my 13.5'x15.5'x8' livingroom is largely open to the rest of the house), but I've heard others say that these panaels are the only type of passive room treatment that they use. Worth a look.

My experience tends to match what Phasecorrect wrote.