How far can room treatments solve boomy bass?

My current room is too small for my Snell Es. I will get a bigger room in the future. In the meantime, haw far can tube traps and wall traps go to eliminate my boomy bass problem?

They can make it better at least. How much they can do depends on the extent of the problems.
Depends on how you address the problem. If you take measurements and do your homework, you'll be surprised. If you just start buying soft stuff, it's guesswork.
Room treatments in a room too small for the speakers is not the answer. Speakers that are to large for the room is one of the biggest problems in audio. I'm a firm believer in room treatments, but it wont fix your problem.
I tend to side with Zman here. The usual sorts of room treatments likely won't amount to much more for you than a band-aid type of fix at best. If it were me and not knowing your budget limitations, I might consider, until you can get a better room anyway, the short-term fix of breaking down and getting yourself some sort of equalizer...yes, I said EQ! Possible insertion losses aside (which I think are often over exaggerated, myself), they offer enormous flexibility in just this kind of situation - expect your bass problems to be solved and then some. Perhaps a nice Rane unit on the used market, or possibly a digital EQ if you only have a digital source - a Behringer DEQ-2496 can be used in a digital passthru mode and costs peanuts...very little signal degredation this way if you are using it between a transport and a DAC for example. There may be other possible candidates out there, you just may have to do some looking, or ask others here. Hope this helps.
Bass traps in the corners of the room can do quite a bit to even out bass response. Even when you go to a bigger room, tube traps will be a help. Treat at least one end of the room (traps in each corner) and preferrably all four.

To with the biggest traps you can get away with--there is no substitute for thickness/mass when it comes to bass trapping (the exception would be "active" bass traps which use a speaker that cancels bass). With the round bass traps, like the ASC tube traps, I like the 16" models.
While room treatments are very important, I think the system used is just as, if not more important, in determining the kind of sound you will hear. Every one I think would agree to try "bass traps" in the corners and to get the speakers off the floor. Also reduce bass reflection from the floor with some sound absorbing material like a rug.
Then invest your entire retirement money along with any other holdings in a brand new, top of the line, state of the art system, and you will be all set.
I don't understand the concept that acoustic treatment for a "too small" room is not the answer. It's exactly (part of) the answer. The modal distribution in a small room is lumpy well up into the upper bass region. The larger the room, the lower the frequency where that lumpy response starts to even out.

If your speakers are so large that the drivers don't "integrate" within the listening space, then yeah, that's a problem, too, but a small room is the worst offender when it comes to acoustic response in the low frequencies. Fix those and things will definitely get better.
In the 3 listening room that I've measured, Hemholtz devices like the tube trap/bass trap can be reasonably effective down to a little below 100hz. In an untreated room, you'll often see a hump in the half octave above that point. I've been pretty successful in taming that with bass traps.

Below that point, I've always had to deal with +/- 10db lumpiness that seems to resist "passive" treatment. I ended up using DRC (Audyssey, et al) to clean this up. I don't know if every room works this way, but it's been pretty consistent in my homes.

Good Luck.

Most likely you have one or several modes.
You can look in to a way of finding out.
Buy a XTZ Room analyzer pro II. It is complete and it'll show you exactly what is the problem. You can also use a Rives Audio PARC. The PARC is easy to set once you have the Room analyzer pro II. You just use the settings that RA pro II will give you, frequency, Q-value and level and feed it to the PARC. If you need to rid such modes most stuff will not suffice. You can also use Svana ( V-6 and V-4. These will do but they are large and very very heavy. I have used all most all Gik Acoustic panels, nothing will rid those low frequent modes. Not even the Monster bass absorbers (4 units) is anywhere near doing what the PARC does.
I use 14 Gik panels now (242,244 and TriTraps) and a PARC (measured with XTZ RA pro II). Best results you obtain by using both acoustical treatments and a PARC. I can assure you, this will take you where you need to go. You should now, bass modes doesn't only affect bass, it affects the whole range. You obtain better clarity, presence and PRAT. No lumpy swollen bass.
Walls create bass peaks. They amplify frequency (and multiples) that is f=1135/(2*L) where 1135 is speed of sound in ft/s and L is distance between front and rear wall (2 is for traveling back and forth in order to add). Larger room should help but you can also use sound absorbing panels. Normally they work the best when they are spaced from rear wall by either 1/2 or 1/4 (don't remember) of the wave (eqv. to frequency amplified by room). In my room it is not even possible and I'm forced to put them on the wall. I bought John Manville 817 rigid 2'x4'x2" (faced) fiberglass panels and glued them to fiber boards. I will stretch fabric on them and hang on the wall. Look at sound absorption coefficients:

At 125Hz it is 0.38 - still OK but less dense (and more common) 814 is only 0.24. It is basically density (weight) of the panel that is amount of fiberglass they used. 4" panels would be ideal but I don't have space for them and there is, of course, WAF. Forget about curtains, blankets etc. If you can hear bass thru it then it won't stop bass reflections.
You can get much closer to unity absorption (which isn't a limit) with 4" - 6" of fiberglass. You don't want to overdamp the other frequencies, though.

The reason spacing off the wall helps is because pressure doubles on a rigid wall while velocity goes to zero. As you move away from the wall, there is a tradeoff between pressure and velocity. No damping occurs with no velocity -- therefore, spacing off the wall (or more thickness) is needed. At lower frequencies, this leads to ~ 6" panels to get effective absorption. Bass traps in the corner become a viable (if unsightly) alternative.
Have you tried tuning your speakers with the ports?
Rolling up a soft piece of cloth and loosely putt it in the ports will help controle the bass of the speaker.
You may have some bungs that come with the speaker for this purpose.
Zmanastronomy, I've tried it but it has to be very loose fabric and it also reduces bass punch. I had more room resonances with previous speakers (two 6" woofers) than new (two 8" woofers). It could be that larger woofers deliver more sound direct (larger area) or it is just better speaker less prone to interaction with the room. Some of the smaller speakers with ports tuned to extend bass have hump on the multiples of port frequency - visible on frequency response chart.
Have you tried repositioning your listening seat in relation to the back wall for the smoothest bass response and THEN positioning the speakers in the room? This is basically the method described by Jim Smith, author of "Get Better Sound". He did this in my room to great effect. I also have 16" Tube Traps, but the proper location for the listening seat (height and distance from back wall) is critical to good, balanced sound, IME.
Inpieces said it very well. Get some GIK Tri bass traps for the corners of your room. They stack on top of each other and go floor to ceiling in the 4 corners of your room.

In addition to these get one bass wall trap panel for the wall behind your listening position. Lastly get two 244 panels for the first reflection points on the side walls.

This will GREATLY improve your total sound top to bottom. Greatly!
before purchasing anything extra make sure of correct placement that is the main culprit of boomy bass. amplification is also crucial in terms of sufficient power to drive speakers.
Yes, placement first. Correct amp to speaker matching is also a first step. After this, all systems should use the treatments outlined in my email. All systems will be improved greatly!
It won't suffice, if you just don't believe me, it is ok with me. But when you measure the room you will see with your own eyes. I have made lots of measurements.
The Room analyzer is so easy and it is within +/-1db. Bass modes are tricky. I had my room drawn to get best online help with ideas and bough very much more units than i was told i would need. It did not do. I also had a pro acoustical company over here to overlook the room and what i had done and other options.
I must admit, it is ofcourse pending on the room. I have noticed many just don't gripe this or maybe, when they understand the costs to do it good, it is a burden they just don't accept. But on the other hand. When we evaluate gear, it is difficult to honestly say what they do or just won't when acoustics interacts as much as it does. The bass "colours" so much. When it is under control, you'll notice an improvment in the midrange and the top end also. Depth, 3-d, PRAT, presence etc etc.
Gears you might have been rejecting, might be good. I have talked to a few dealers aware of this and they also say, many people ending up repeating mistakes based on faulty assumptions. I think it's a bit sad. I've been through 11 apartments and none of them was perfect, far from it.
A small room can actually work good if taken care of. I am no expert, far from it. But since i have leveled alot with Gik and the pro company overhere i have learned that i must cope with what matters to void even more costly mistakes.
I would start off buying Tritraps stacked on top of each other in all corners. Also using 244 and 242 behind the speakers and if possible, 242 or a diffusor in the ceiling.
The PARC is an analog piece of equiptment and not as most of them, digital. When you use the PARC, the Gik (or similar gears and brands) gear is actually making even more sense. I am not writing this to stomp on anyones toes. I do it due to the fact i now know, i should have gone this route earlier. I know this phenomena cause quite a stir in the head for some. It might seem a bit "too much"!
True and fully working low frequent absorbers must be huge to work. Those small devices doesn't "fix" low bass. This is why the PARC is existing in the first place.
Sorry if this seems like bad news coming from me,... i truely am.
Martykl and Inpieces, is the DRC or Rives Audio PARC some sort of room analyzer, or itself an EQ? Sounds like the PARK stays in the system and equalizes out the room nodes?

How does analyzing the room and knowing what's wrong help? Guiding your choices in room treatments?

Ivan, is there such a thing as a high quality equalizer, either graphic or parametric? And where does it go in the system?

Ivan, I'll try the ports. Think a hand towel is good material?

Given how many people have room problems and throw thousands at the room and equipment, you would think somebody would make a "hifi acceptable" parametric EQ to just deal with these nodes. With 22 tubes and platinum knobs :-)....then nobody will diss it. Maybe the PARC is along these lines.

Thanks everyone!
You can't fix acoustic problems with EQ. You're using the wrong tool. Fix the acoustics, and THEN see where you stand.
My understanding is that the PARC is an analog variation of room EQ. Audysey, ARC et al work in the digital domain. I'm not sure whether PARC includes an RTA function (room analyzer), but if it doesn't you'll probably use a stand-alone RTA for set-up.

As to Ja2's contention that you can't fix acoustic problems with EQ, I'd respectfully disagree. Respectfully, but emphatically. Modern parametric EQ is an amazing thing and - to my ear - makes a bigger improvement in overall sound than just about any other change you'd make in a system. To test this claim, find any AVR with Audyssey and do a "before/after".

As always, however, YMMV.

Martykl, It is not only issue of loudness but also extended decay time. I also feel that additional pieces of electronics in the signal path don't improve clarity.

I agree with Ja2austintx assessment: fix the room, then decide.
For those problems that are caused by uneven modal distrubtion . . . why not fix them where they live, which is in the acoustics? Trying to EQ out the lumpiness is just fighting the symptom, not the cause.
To be clear:

1) Per Kijanki, EQ is not a "magic bullet" that fixes all problems. It is - IMO - a magic bullet that fixes one BIG problem.

Per Ja2) FR issues below 150hz or so have been IME virtually impossible to correct with traditional room treatments - including tuned Hemholtz devices.. Even if you fir out the walls to achieve ideal (or near ideal) relationships, you still have serious FR issues in most rooms with most speakers.

For instance, you will end up with destructive interference - unless your speakers are mounted on the wall or soffited into the walls. Quarter wave effects generally result in gross FR deformation (>10db at some point in every room that I've measured) below 150hz. Parametric EQ can bring that to virtually dead flat (depending on the system you're using). I find the delta instantly and dramatically audible. A simple visit to any HT retailer will allow you to A/B Audyssey. Form your own judgement, but I would be shocked if anyone missed the impact of the parametric EQ.

This certainly doesn't mean that everyone will like the sound of such a system. But, for the OP's question regarding a room too small for his loudspeakers, I don't know of any alternative to EQ. Even in a good sounding, fully treated room, I've yet to find a passive room treatment that is effective much below 100hz where these effects are so clearly audible.

I'd agree that traditional passive treatments are useful for many problems (particularly as Kijanki noted, issues related to the reverberant field - slap echo, etc.). That is why my listening room is heavily treated. However, I still use Audyssey. If you wanna fix the bass, there ain't nothin' like parametric EQ.

YMMV (but I kinda doubt it.)

Don't you agree that proper acoustic treatment reduces the amount of EQ required to bring the response into "flat" (or "desired") response?

Also, can you elaborate on the specific quarter-wave effect you are seeing in rooms? Are you talking woofer-to-floor distance, woofer-to-front-wall, etc.?
Martykl, Yes taming low bass might be difficult but it is doable. My panels won't work well below 125Hz, according to datasheet, but 4" panel would. I hope that putting 2" panels on opposite walls will increase damping at low frequencies. I will know more after my panels are up.

EQ is not a magic bullet because it does nothing to long decay of boomy bass. That's perhaps why they spend fortune in recording studios and concert halls on acoustic treatments before playing with equalizer.

I would try speaker positioning, try different electronics and cables, apply acoustic treatments and then EQ. Boomy bass in my room got better with different cables to be further improved with class D amp to finally become more even with power conditioner. All this before room treatments.

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.


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"?


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.
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.

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.
Monitors are perhaps a safer move. Assuming that people seems to go through acoustics half hearted. The risk with fullrange speakers (most often floor standers) is always that bass modes will be unavoidable and it cost some to get the bass modes an the rest under control.
Looking through some threads, also talking to acoustics that work this every day, has made me understand. None of the audio-bugged i have visited has done what is needed to make the environment nearly as good as the rest of the system.
Another bizarre thing here is cable dealers, who claims this can be solved with different cables. I guess a graph can tell each and everyone how much bass modes and dips can affect the whole frequency range. Basically, the room (environment) is as important as the system.
Any cable that corrects room response issues is seriously broken. Why do people fall for this crap?
The cable makers have to make such claims in order to justify the high prices asked for their products. But this is off topic.
Man I tell you boomy bass used to be thought of as a problem solved with few interventions and no fancy sophisticated acoustical analysis computer programs were employed. Has the OP tried any of the suggestions and if so what are the results?
Good question, i have tried them all. What i ment was, hope he does not fall for a sales-hype that can come in many different suggestions. I also ment, that an idiot must realize reading a graph, that not many things can solve bass modes of significant + db's. I can measure a somewhat result of a bass panel absorber. What they do for a low bass peak mode is pretty much nothing. That is raw fact. A XTZ RA pro II cost no more than a rather cheap power chord. Such kit's did cost alot a few years ago. Don't rely on things you can't verify. There are to many vested crooks wishing to earn your cash. When i mention this cable soloution, it is actually a suggestion i was getting from a manufacturer. He was so into this i began to wonder if i could walk on water buying a set of his magic cables. Ah, you get the point. I suggest the OP try to mail Richard Bird at Rives and also Gik acoustics, just to see what responses he'll get. Both companies are very nice. From this point he can figure himself what to do. As mention and to repeat myself, the RA pro II is not to throw money for the pigs. It is a good way to actually see, understand and learn what to do.
Mechans, ofcourse. Back off a few years or more, such programs (complete kits) was very much more expensive and not as good. Not to to mention, as easy to use. The XTZ is advanced and great quality for a more than a resonable cost all new. This is also why many companies could rely on the fact, we could not check facts for ourselves, but rather relied on their sales-hype.
If one implements the wrong solution for an acoustic problem, then yeah, it's not going to work very well. But if I have a spike at (say) 43 Hz, and I install a tuned acoustic filter (Helmholz, etc.) designed for maximum absorption at 43 Hz, and things don't get better, then I either need

a) better placement
b) more filter

This isn't voodoo.
Nope, it should work. It's probably more of *b.
I used Varitune V-6 before and more of them, absorbed more db. Using the PARC, i just deduct more level, if needed. I also have 43Hz as a major peak
For OP, if you can measure your room with XTZ RA pro II, you can order special tuned Scopus Traps. This way (measured), you can start off buying only several Scopus to start off ridding the modes. Measuring helps you and help Gik with two things.
1) Determine at what frequency or frequencies you'll have the peaks.
2) The actual level in db the modes are.

If you do not measure, you'll have to guess and might end up absorbing less specific which in turn, will not help you ridding the actual mode at that degree you'll need.
When measured and you know the actual level in db of the mode(s). You can tell that to Gik and they will be able to tell you how many panels you'll need. Also, custom make them to absorb (better/more) at this or these frequencies.

When that is done and installed, you can easily determine if you feel more panels are needed. Maybe not!
Ceiling usually is a problem. Concrete walls and ceiling can give a harder reflection. Some usually blame cables for being bright, this can be due to the ceiling, walls. Glass (windows) are even worse.
I use 242 in the ceiling, but if i had bought now i had bought GridFusors. Placement in ceiling you can spot doing like this. Sit in your listening position, have a friend walking at each side between speakers and where you sit. When you see left speaker at left side that is first reflection, when you'll see right speaker at left side it is second reflection. Ofcourse, you can do same at right side of listening position. In line between these sides, the ceiling reflections are located. Now you can determine where to put ceiling panels aswell as side reflection panels. For example, in my room the ceiling reflection has a huge impact.

Bass boom:
For instance, i have a big mode at 43Hz (around 19db!).
So for me it had been wise to try Scopus and ask Gik to specially tune a kit of absorbers as close as possible to absorb at 43Hz. This i had never known if i couldn't measure my room. I can measure in corners and listening position where modes actually develops and at what specific frequencies. I can also see where in the range i have big dips (opposite to modes/peaks).
Sorry River251, just noticed your Q above about an actual HiFi-quality parametric. What I use is a Ric Schultz-modified Behringer DEQ-2496. Have a rather minimalist 2.0 system: Onkyo carousel changer as transport, out to a Monarchy DIP Combo, out to the DEQ being used as my DAC, from there to a pair of Endler Audio shunt attenuators that are plugged directly into the inputs of a pair of Monarchy monobocks. About $2k worth of Alan Maher Design's power-conditioning stuff rounds out the electronics. This is a single-sourced, CD-only system. The stock sound of DAC section of the DEQ is unacceptable for HiFi. However, many choose to use it between a transport and DAC - that way the DAC section of the DEQ itself is bypassed altogether and all the DEQ is responsible for is signal processing in the digital domain and this does improve the sound dramatically. About the only issue to deal with at this point is the cheap, stock switching power supply. It's unreliable as well as a bit noisy. Ric's mod gave it a quality linear supply. But, I took things a bit further and let Ric replace the stock analog output stage with one of his own design and opted for an updated DAC chip as well. This allowed its use as a HiFi-quality DAC with true, differentially balanced analog outs to the monoblocks. The cost for the DEQ and the mods was around a whopping $625. If you need an analog input as well, Ric can mod the existing input circuitry into something equally HiFi-worthy for a few hundred dollars more. But, for me the sound is glorious and the flexiblity is unparalelled and all that. The DEQ itself has 10 bands/ch variable from 10 octaves wide to 1/10th octave narrow at more than 330 individual center frequencies from 20-to-20k in 1/2db steps. All that with 64 user-defined memories. The processing is 32-bit. There is no volume out control on the DEQ (except for up to -15db at the DEQ's input to accomodate higher-gained sources). The DEQ has a steeper-than-analog learning curve to it, but you'll get passed that after a while...took me almost year to begin to feel really comfortable with it, but I was a bit impatient about it, as I recall. But, I dunno how to answer better your Q about what you might want without knowing your system architecture.
Thanks everyone, I'm just reading and trying to learn. When I can afford my next step, it will be getting the equipment to analyze my room.

But Ivan, I am using a Creek CD43 MkII right now, with an optical (toss link?) out so I think I can accommodate the Ric's stuff, which would be my second next step. Can you provide contact info? I should talk with him. I'm really glad that through both analytics and room treatments there is some hope.

Martykl, where in the source-speaker chain does the PARC go, and how will it affect sound quality?

Thank you all so much, this takes things to the next level. Quality sound is worth the effort...

How long before you have your larger room?
Jim, i did not notice Martykl uses a PARC, but i do.
PARC is between pre and power, or if you'd use a cdp with volume, between cdp and power.
You can bypass it if needed and it is both rca or fully balanced (xlr).
It works the range 16-350Hz and 1-3 modes per channel individually set (left/right).

Affect sound quality, it does not affect in terms of resolution. Maybe if you use ├╝ber expensive gear. I can't answer that. If you look at mys system under Nearfield you'll see what i use.

I've never used a PARC.

My DRC set-up has evolved from using an NHT X-2 active x-over between my ARC LS-25 and VT130SE. The NHT fed a Velodyne SMS-1 subwoofer management system, which fed a pair of powered subs (originally Velos, then Rythmiks). This arrangement EQ'd only the signal headed for the subs and put only the NHT in the main path. It worked very well, but was kind of kludgy - 4 boxes to power up, etc.

I also maintained a parallel system in the same room with Joule and Cary or Prima Luna electronics that allowed for a non-EQ alternative, that I used mainly for vinyl.

Separately, I had also been using Audyssey in my HT room for years. When Stereophile did a very enthusiastic review of Audyssey XT32, I picked up an Onkyo pre-pro that contained this system. I figured that I'd try it out in my main 2 channel room and - if I didn't like it - I'd just use the Onkyo to replace my older pre-pro in the HT room.

Bottom Line: The ARC and Joule came out, the Onkyo went in and has never left. All sources - including vinyl - get the full XT32 treatment. I understand that this requires me to turn in my audiophile merit badge, but I simply prefer the sound this way.

Ric can be contacted at his website EVS audio (Electronic Visionary Systems) and his location is in California. From there you can email or just phone him as I do. You'll find Ric very easy to talk to about anything. Just make sure with him (or me) that your Creek and the DEQ are compatible for whatever you have in mind...OBTW, your next step will likely reveal that Toslink, compared to SPDIF, is grossly inferior soundwise. Coax, if you can swing it (the DEQ can), will be a big step up!

Update: just looked up the Creek on their website - it does indeed have a coax digital out (or at least the original CD43 did, I'm assuming the MkII does too). Should be an excellent transport for anything like the DEQ, which itself will give you 96k upsampling which will, compared to your non-sampling CDP, will greatly smooth out the highs - decidedly less rough or ragged sounding, for extension, that will likely help a bit with imaging too.
Inpieces and Martykl, thanks much, that helps clear it up. Onkyo makes (or did) some excellent tuners. I would imagine it sounds good.
Ivan, thanks, that's great news! If the sound can be better, all the better. I already get incredibly good sounding highs with the 8B and PV-5. Cymbals sound like wooshy brass. No ssshhhh. Or at least I think it sounds good.

Just saw this thread. I have a high resolution system that includes a PARC. The PARC was the only solution, after ASC Tube Traps to reduce a couple of modes at 31 and 62 Hz present in my room due to dimensional causes. The difference in soundstage, transparency and elocution is significant. It does not affect sound quality at all. Bear in mind, however, that it does require careful setup, preferably with a real time analyzer and then some subsequent tuning by ear. Rives Audio provides a system called BARE that utilizes a microphone, laptop, and a soundcard to provide the initial setup. Good luck.

The PARC is not transparent. It sucks the life out of the music. It does do an amazing job on bass, and that alone can make a huge difference to the whole presentation of the music, but it does degrade the sound in the mids and highs.

I had a panel of listeners do an a/b test with violin and harp and it was quite unanimous that many of the fine details were lost.
I wouldn't go against Madfloyds input. But it is not a bad choice buying PARC. As always there are different opinions. But to be clear, this is among the very best of choices. I experience no sucked out life in my my system. Buying a digital dito with inbuilt dac means you no longer can obtain what cdp you prefer as those digital room tuners uses the inbuilt dac.
Buy a used PARC and try it. Or have a home trial. Do remember, the room should be measured or you'll end up setting it up wrong. It is very much more difficult coming anywhere near using an analog spl meter than for instance XTZ Room analyzer pro II. I should now, i have them both. I also feel i have to put another thing into this subject. When you measure, set what data you'll get at the PARC. Also try to change levels of deduction at the PARC. That is to say, if you are about to drop 10/5 or 3 db as an example. Do try to go back with 5-10% increments in level.

Do this until you are satisfied by ear (fine tune by ear). The data you'll get from Room analyzer will give you frequency, Q-value and actual mode(s) in db. It is the db levels you tune by ear if you feel it don't sound as good as it looks when measured.
This will all be veryfied by Richard Bird at Rives.
It is very easy if you get the PARC and Room analyzer.
For best results, also try acoustical devices. Gik acoustics is a good choice as mentioned.

I have a wide and deep soundstage which is very vivid and smooth with great dynamical impact. I wouldn't even jump this thread give my point if i wasn't satisfied.
Room treatments, if you haven't guessed already ,can have a tremendous impact on the sound of the bass your system puts out. Are you convinced at this point?