Room correction room system vs ears….


So, I splashed out and spent more than I wanted to on a nice little Benchmark amp and preamp etc and since I’ve gone that far I got curious about a room correction system for this and it’s going to cost me over a grand apparently. As far as I can gather these dial in the music before it comes out of the speakers…?

 

im wondering if I simply messed around and found the sweet spot without a room correction system how much of a difference this would make. I’m far from savvy with audio and try to keep things simple for my simple brain, so, on a scale of 1-10 how much difference would I percieve by splashing out on a room correction system?

thomastrouble

I am a devotee of high quality DSP room correction.  I have done some room treatment, heavy curtains behind the speakers, overstuffed furniture, etc., but my system didn't come into focus until I had programmed my DEQX DSP room correction and reprogrammed and reprogrammed it.  Right off the bat I decided to sacrifice seven or eight dB of woofer sensitivity to enable equalizing the bass by pulling down peaks instead of attempting to boost dips.  This was possible because I had all kinds of headroom in the bass, 104 dB/w/m sensitivity woofers  coupled with a 300 watt amplifier for the four ohm load of the woofer.

Programming the DEQX room correction was a monumental task for me, but I kept refining it until my fully horn loaded, triamplified, DIY speakers sounded quite good to me.  Then I read about company approved DEQXperts one could engage to give the DEQX DSP a truly professional programming by means of connecting PCs and holding a Skype call to get the work done.  I hired DEQXpert, Larry Owens.  He turned out to be brilliant at the task.  After performing speaker calibration, speaker correction, time and phase correction and finally room correction My DIY speakers sounded absolutely splendid to my ears.  Larry hit it out of the park.  This was 2017, and I have had no need to change anything with the DEQX.  The system has a smooth frequency response from the low 20s up to 20 kHz.  It is properly time and phase aligned and the crossovers at 200Hz and 8 kHz (16th order) are inaudible to me.

I have some experience with automatic DSP room correction with my Marantz AV pre/pro in my HT system, and while it wrought some improvement it is in no way comparable to the results that can be achieved with a high end DSP  like the DEQX.

Many of the DSP non-subscribers must have marvelously paired speakers and rooms. Somehow every room I've ever used did have plenty of issues, bass mostly.

While plenty of treatments (to the point of needing to close one's eyes) do work, I could not happily live with my current system without the DSPeaker Anti-Mode 2.0 room correction unit with digital equalization.

While it's not a bad room and the sound is anchored by Raidho D2 floorstanders,  the room still had an effect on bass flatness and response, and the Raidhos have a small bass 80-120 upper bass hump that needs tamed (at least to me).

With room correction performed, and very judicious and minor equalization, the speakers are very flat (+-2) from 30Hz-10kHz. The difference is stunning. All of the Raidho resolution and tonality remains with the excess bass removed.

Anyone who has heard the A/B comparison with the bypass on or off has immediately noticed the more open transparent sound with room correction and DSP activated, and with true flat bass to 30Hz. It sounds great, and my DSPeaker unit is a non-negotiable 'keeper' in my system.

@thomastrouble  A $10,000 system can sound fantastic too!

Here is my friend's system that I thoroughly enjoy:

VPI SuperScout TT w/Dynavector 20X2 H

McIntosh C20 version 2 pre-amp

RAM RM-9 amp

Kyocera X310 CD player (new caps)

Von Schweikert VR 35 Export speakers

Grover Huffman Empress cabling throughout

Sure, it's older and now obtainable as used gear only.  But for $10K, try to do better and the speakers are designed to be within one foot from the front wall, room friendly.  

My Ears told me something was wrong. Room treatment helped but something was off. Measured and sure enough 2 big humps causing over done bass. Used Roon DSP convolution filter to fix those humps and wow.   Keep it simple and room correction is great. 

Maybe consider something like a TDAI 3400 or 1120 amp, which comes with a microphone and tunes itself up.

And there are probably cheaper options from NAD and others.

 

… going slow is often wise.

Holmz, I wish I could answer that but I’m pretty clueless - I don’t know what both concepts mean. I’m far from savvy on these things and saw a room correction ruin as something of a magic wand that “just fixed things”. Regarding using the subwoofer - I know I’m going to have to deal with taming bass reflections and my knowledge, based on common sense is I’ll have to lay a large carpet on the wooden floor, install bass traps and possibly install curtain rails and heavy curtains on all four walls that I can open or close gradually based on trial and error. Soft furnishings are going to help also, but then again this is all about bass….I’m still wondering what a room correction system will get me beyond that.

You guys are pretty hard core serious from what I’m reading here - I’m too, too busy, too old and not “audiophile” enough to go to those lengths Plus, I know I’ll never be 100% happy because I’m dealing with the limitations of living in an apartment. 
I got hooked years ago when I bought some Magnapans and great amps, I was completely blown away - it was like I had just heard music for the first time but I’ll never come close to that experience again and I know that, I’ll just be content to get the best out of my apartment system, accept lower volume levels and not be wrecking my brain in the process.

I have no doubt you guys would think nothing about spending a grand on a room correction system and I wouldn’t have a problem neither of it was a “big” hobby for me but it’s not these days, it’s more about not just throwing together about $10,000 worth of gear and getting $2000 benefit from it when maybe something like a room correction system could make that difference.

Hey guys, just do I don’t seem unappreciative…..flew back to Brazil last week, takes 30 hours from door to door and was completely bogged down with work when I got there and one week later I’ve made to same trip back to the US…..haven’t been on emails for a week and just opened this - wow, a lot of talk in the last week. Gonna read as much as I can tonight as I just landed a couple of hours ago.

Thanks a lot guys!

Same thing happened to me with absorption panels on front and rear walls-dead sound, lost dynamics and all interest in the music.  Acoustic Fields sold me 8 large panels which even a pair on either front or rear walls killed the sound.  I prefer the SR HFTs which diffused the sound with live sound remaining.  Only the side walls and ceiling have absorption (well, the carpeted floor too with 106 oz.plush).

im wondering if I simply messed around and found the sweet spot without a room correction system how much of a difference this would make. I’m far from savvy with audio and try to keep things simple for my simple brain, so, on a scale of 1-10 how much difference would I percieve by splashing out on a room correction system?

  • If the room is troublesome then the room correction would make a big difference.
  • If there is passive absorbers and bass traps then the effect of a s/w correction is less.
  • Ideally one would do both
  • Much of the problem is in the lower frequency room modes.

 

There are also the Dirac systems, which do impulse response and phase correction… so one can envision them as doing some EQ of the room, and some EQ of the speaker.

@thomastrouble are you talking about:

  1. Room correction and frequency EQ?
  2. Or impulse response EQ 

I assumed that rear ports were for low frequency but just found in my room the high frequencies sounded flat when I had the an absorption panel right behind the speaker. 

@kota1 I know what you mean.  I was at a high-end dealer a while back and the room had absorptive panels all around and the music just sounded dead and over damped.  Very interesting about using diffusive panels behind speakers — learn something new every day. 

“On the front wall (behind speakers), diffusors tend to work much better than absorbers”

+1, @thyname 

That’s been my experience as well. I have a combination of diffusers and absorbers strategically installed in my room. 

I tried using absorption on the front wall in my prior home and current listening room and did not like the dulling, lifeless effect.

On the front wall (behind speakers), diffusors tend to work much better than absorbers. I have about 65% of my front wall surface coverage using GIK Alpha 4a (1d). diffusers (even thicker, the Alpha 6a 2d) work very well on the back wall (behind the listening position). I have a combination of absorbers and diffusors on my side walls, and absorbers only on ceiling.

 

@holmz , I think the ports requires a certain amount of distance from the wall. The bottom line it was simply too much absorption with or without the port. Check the :36 minute mark in this video:

 

@kota I tried using absorption on the front wall in my prior home and current listening room and did not like the dulling, lifeless effect.  I use Synergistic Research HFTs instead on my cherry plywood finished front wall which apparently diffuses the sound and prevents bright or glaring sound coming back at me.   The alternative suggested by several acoustic engineers was for quadradic diffusion paneling.  Unfortunately, the required size intruded into the room from the wall 12" and too much for my room.  

holmz , I assumed that rear ports were for low frequency but just found in my room the high frequencies sounded flat when I had the an absorption panel right behind the speaker

@kota1 - I still do not understand what you mean?

What do you mean… and how do the ports apply to the statement:

  1. The panels decreasing the distance, causes the port to reinforce gthe bass more?
  2. The panels suck out later reflections, and the ports have nothing to do with the brightness?
  3. Or something else?

@holmz , I assumed that rear ports were for low frequency but just found in my room the high frequencies sounded flat when I had the an absorption panel right behind the speaker. 

soix , good question. Those front L-C-R speakers are ported and when I tried placing panels behind them it absorbed too much high frequency info and sounded flat.

I always assumed that rear ports were not carrying a lot of high frequency content.

@navyachts

On the lighter side of things, I find putting my bookshelfs on the end of my mattress and then pulling the sheets over my head works wonders.

I’m guessing that makes it easier to reach your books without getting out of bed, I might try it.

On the lighter side of things, I find putting my bookshelfs on the end of my mattress and then pulling the sheets over my head works wonders.

@soix , good question. Those front L-C-R speakers are ported and when I tried placing panels behind them it absorbed too much high frequency info and sounded flat. With a little trial and error I found placing combo panels between the speakers worked better. The front of the combo panel is a diffusor and behind the panel is about 2 inches of acoustic foam for absorption. I also have floor to ceiling bass traps in the front corners, that may be another reason I had to adjust the panels for less absorption on the front wall.

@kota1 Interesting that you don’t appear to have any panels behind the speakers.  Can I ask why?

@fleschler , this diagram illustrates how I placed my acoustic panels (note the ceiling, absorption in front and diffusors behind the MLP:

@fleschler , it is funny how we seem to have followed similar principles but you have the "custom" version with a purpose built room. Those absorption panels hanging from the ceiling are often called a "cloud" in the studios. I have an acoustic "cloud" of diffusors (auralex acoustic lens) hanging below my PJ in the back third of the room. I don't have a pic but this gives you an idea. This pic is NOT my room, its a studio. These are the panels I use but  this gives you an idea:

 

@kota1 My room is treated much like yours, no spacers on multiple side wall absorption panels, very thick carpet and couch.  The ceiling absorption panels are chain suspended about 6".  I'm still looking for that 2019 video of my finished empty room.

@fleschler I look forward to more pics and if you have time the FR graphs. Would be very interesting to see before and after FR curves with the HFT system.

@kellyp , I use spacers on the absorption panels of my back wall (about 2") and it helped. On my side walls the spacers sucked out too much and found no spacer worked better. I have carpeting and cushy furniture which absorb on their own, other rooms would likely be different.

Keep your wall treatments 4" suspended from the wall.  Often overlooked. 

I have not used it yet, but I have a Mini DSP Studio SHD which is a DSP unit using Dirac Live, it is placed between digital front ends and the DAC. I have already got a large amount of room treatments and bass absorbers I made myself in the room. I've been waiting for my pre amp to get back and now that I have it I will try it out when I get back home from Florida for the holiday season in Nov/Dec.

If you use Roon (if not I advise you to..) you can just make a REW measurement and then manually plug the proposed REW filters into the Roon EQ soft ware. From there add your own adjustments after careful listening. 

In my custom listening room, I have built in bass traps.  I end with a live room, treated on walls, ceilings and floors with absorptive materials.  Trying the same on front and rear walls decimated the dynamics and high frequencies.  I chose to use Synergistic HFT system throughout the room which are rather inconspicuous and tame the high frequencies in front and rear adequately by dispersing them.  So no ringing and a delayed response from hard wood reflective surfaces.  

The goal in room treatment should be a reflected flat response. Yes, absorb the bass but don't also absorb the high frequencies. Just disperse them so they can't ring. I really like racks of LPs as my main treatment. Bookshelves can also help.

I've used digital room correction for years, first as a plug-in to Foobar2000, and now with Minidsp's Dirac Live box. I rent and am a fixed-income. The former means I deal with rooms that are sub-optimal, acoustically. The latter restricts how much I can spend. The Dirac Live box corrects both frequency and time domains, and for my application, it's well worth it.

The weakest link in most stereos I've heard has been the room. I'd do room correction before I upgraded anything else, but budgets and rooms vary, so YMMV.

@mesch I am with those recommending to treat the room 1st.  I made my own panels using rockwool 60 in 2x4' sheets 2" thick framed with 1x2" pine and covered with fine burlap fabric.. To start I would place them at the 1st reflection points on side walls, behind speakers and behind the listening chair if the back wall is close. another 1+ regarding room treatment and locating speakers in the room before buying DSP or whatever.

+1 with Mesch regarding building your room treatments on your own. Much less expensive and you build just what is needed for your individual hearing. 

+1 on working on speaker location. Never had a perfect room that fit with a golden triangle, etc. You can google this stuff and it is just a place to start. Would recommend checking out Zu Audio speaker placement. They have a slightly different approach and I thought it helped me. Right now, one of my speakers is within two feet of the side and front walls. The other speaker is further out in the room and actually closer to my listening position. The sound is balanced with a wide soundstage. Small tweaks until it is "perfect". 

Thanks for listening

Dsper 

 

 

 

 

 

 

=-

 

 

 

 

 

 

 

 

 

 

 

 

=+

@lemonhaze

OK, some good advice here. All rooms need treatment, it is paramount for good sound. EQ/DSP may help after getting the room sorted out. The problem with room correction electronics is they can’t reduce the overly long decay of sound in an untreated room, how can they? They also can do nothing about the full nulls created when low frequencies recombine out of phase. It does not matter how much power you pump into the speakers the sound will just cancel with the same power. Partial nulls can be boosted but if you try and correct for example a 15dB dip you will not have enough power. It requires a doubling of power to achieve a 3dB boost. Try doubling your amp’s power 5 times!

That’s what Krell is for: you too can break your speakers.

When sound is left to decay naturally in a small space (the average room) detail is obscured by the confused and smeared sound. So determine the required time it takes for your sound to decay by 60dB across the full spectrum, known as RT60 or T60. The average room needs T60 to be about 300 to 400ms.

RT60 (and T60) is somewhat ambiguously named. The 60 dB decay thing is the original Sabine equation. T60/T30/T20 are methods of measuring the decay time (they all return the same result, the lower numbers just extrapolate from a smaller drop in level).

Typically mixing rooms have a lower decay envelope and preference for a listening room will depend on music preference. I like electronic and studio-assembled stuff so I’ve no use for added warmth or envelopment from longer decay times (which benefit classical, for example) so my room is closer to a mix room, around 200 ms. Regardless of preference you also want consistent decay across the frequency spectrum (there’ll be an increase in the lowest octaves).

The thing to do is download a great free program REW and measure your room. You will need to buy an inexpensive mic. for the job. This can provide a CSD plot of your room showing the peaks and nulls. Yes, you will need bass traps. REW can help you best position your speakers and show the effect subs have on the performance.

Smaller rooms (most people’s listening rooms) complicate things a bit as decay to a uniform diffuse field doesn’t happen and RT60 isn’t super-accurate, so listen and judge accordingly. REW has a new method for smaller rooms, so try that.

Multi -subs can and should be used to smooth out the bass response. The optimum would be to treat the room in combination with 2 or 3 subs and you will get to hear, probably for the first time, the music info that has been ’black-holed’ by the nulls. Some who have heard of multi-subs envisage thunderous bass but properly placed and dialed in they enhance the entire spectrum from top to bottom. Think of them as tuning units.

WARNING: place a cushion between your feet in case your Jaw hits the floor 😁

Careful positioning of full-range stereo speakers to minimise nulls followed by judicious EQ to tame peaks at the listening position will often work (or it does for me, in an open timber house but will depend on your room characteristics, so quite different in a concrete apartment block) and yes the difference is dramatic. I don’t need bass traps specifically (approximation of reverb time rises to ~400 ms in the 31 Hz band which is still fine) but I need to reduce a 15 dB peak at 50 Hz (from the room’s second longitudinal mode) at the listening position. Subs give bass extension for limited-range speakers of course, and two or more subs can be located to give more even bass response over a wider listening area. Setup is more complex in that case.

One of the best articles describing small room acoustics in reasonably simple terms is this one, covering decay and the different frequency ranges (specular, transition and modal) to consider when setting up gear and a room.

@lemonhaze : great post! And spot on.

 

Those who think they can fix their room with some Roon EQ and able to get "perfectly flat frequency response" are just fooling themselves. 

I'm constantly amazed by before and after demonstrations at audio shows. I've since made it a point to always follow those demonstrations with a visit to an LP source analog demo where my shoulders never fail to drop and relax. Eyes rolling?

On the other hand it was suggested to use an Altec equalizer with my Octavium sub while dodging the draft and have been equalizing and optimizing subs ever since. 

OK, some good advice here. All rooms need treatment, it is paramount for good sound. EQ/DSP may help after getting the room sorted out. The problem with room correction electronics is they can't reduce the overly long decay of sound in an untreated room, how can they? They also can do nothing about the full nulls created when low frequencies recombine out of phase. It does not matter how much power you pump into the speakers the sound will just cancel with the same power.  Partial nulls can be boosted but if you try and correct for example a 15dB dip you will not have enough power. It requires a doubling of power to achieve a 3dB boost. Try doubling your amp's power 5 times!

When sound is left to decay naturally in a small space (the average room) detail is obscured by the confused and smeared sound. So determine the required time it takes for your sound to decay by 60dB across the full spectrum, known as RT60 or T60. The average room needs T60 to be about 300 to 400ms.

The thing to do is download a great free program REW and measure your room. You will need to buy an inexpensive mic. for the job. This can provide a CSD plot of your room showing the peaks and nulls. Yes, you will need bass traps. REW can help you best position your speakers and show the effect subs have on the performance. Multi -subs can and should be used to smooth out the bass response. The optimum would be to treat the room in combination with 2 or 3 subs and you will get to hear, probably for the first time, the music info that has been 'black-holed' by the nulls. Some who have heard of multi-subs envisage thunderous bass but properly placed and dialed in they enhance the entire spectrum from top to bottom. Think of them as tuning units.

WARNING: place a cushion between your feet in case your Jaw hits the floor 😁

Physical Room Treatments +1

Electronic Room Correction is a band-aid. It just covers up the problems and is Not a Permanent Solution.

I have been using digital signal processing since 1995. It works incredibly well for subwoofer crossovers, full range room control and speaker balance but it has it's limitations. Doing this right requires the right room with all early reflection sites dampened depending on the type of speaker used. You do not want the frequency response drifting more than 5 dB up or down or you will run out of amplifier power correcting the troughs and drop resolution dropping the peaks. Newer processors like the Trinnov Amethyst and the DEQX Pre 4 and Pre 8 are so fast that running out of resolution is no longer a problem at any volume. These units measure, with there own calibrated mics, the frequency response, timing and phase of each individual speaker and subwoofer. They then flatten the frequency response curve, and correct group delays so the the sound from each speaker gets to the listening position at exactly the same time and in phase. Some of then will then overlay a desired target curve. I then measure the main loudspeakers with an independent calibrated mic and make any adjustment needed to get their frequency response within a dB of each other from 100 Hz to 12 kHz. The result is spectacular imaging which is the first characteristic that other audiophile notice. 

Don't spend any money upfront, first hang some rockwool (Home Depot, Lowe's, etc.) on the walls and see if that works for you. If it does, then to make it attractive you will know how much to spend and what to spend it on. Have fun!

Minimal 'Inexpensive' Room correction via room treatments is quite doable. There should be little to NO excuse Not to try some things, On the other hand I just got DiracLive and though I have a poor experience wiht NAD T748 and it's early version of room correction, the DiracLive did marvelous things to my sound experience. Don't forget Speaker placement. A couple of inches in any direction and in their placement change everything, If you move you speakers remember that you will have to Retest your DiracLive or they will just be a constant sore spot, Possibly even destroying your sound experience.

I also agree to try room treatments first.  Experiment with them in different places.  To me, room correction is taking away your true sound and replacing it with something manufactured, I.e. fake.

Home Audio Fidelity or HAF will create convolution filters for Roon based on measurements you take. Results are remarkable. Customer service is top notch.

I am with those recommending to treat the room 1st.  I made my own panels using rockwool 60 in 2x4' sheets 2" thick framed with 1x2" pine and covered with fine burlap fabric.. To start I would place them at the 1st reflection points on side walls, behind speakers and behind the listening chair if the back wall is close. 

Play with speaker placement within the room as is and then make adjustments after treating room.

Keep in mind that one is tuning the room for one's own hearing.  

Use the money saved to purchase a outboard DAC for your node. 

Good luck in this endeavor. 

Take a look at the Sumiko Master Set speaker positioning method you might find it helpful. Good luck !

Some DSP in a room beats none, even in a 'meh' room....I count on it, as ears can lie to one's mind, whereas a mic and software don't care about prefs....ho, as usual.

 

Splish, splash you're taking a bath!

Might as well jump in with both feet

and buy the Professor's system as demo'ed

at Axpona in Janszen's room. Only $23k

as I recall. Tiny sweetspot. But yes jaw dropping!

Or buy a TigerFox enclosure for $500!!