(Objective) Room Correction systems comparison - do we have that yet? - AVS Forum
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post #1 of 31 Old 11-21-2012, 04:55 AM - Thread Starter
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Hey guys,

if something like this already exists - please forgive me. I did not find anything.

What I want to know - do we have a proper, objective comparison of (automatic) room correction results from different systems?
By that (proper, objective) I mean:

- one/same room for all compared systems
- same mic and speaker positions for all measurements (i.e. no changes to the room whatsoever)
- (indepenent) measurement before correction
- (indepenent) measurement after correction of each system

Interesting systems for comparison would be:

- Audyssey MultEQ XT
- Audyssey MultEQ XT32
- Anthem ARC
- Yamaha YPAO (RSC)
- Pioneer Advanced MCACC
- Trinnov

- Dirac
- Acourate
- Anti-Mode

- others



I'm sure someone has compared XT vs. XT32 like that some time... but what about the others? Do we have some data / measurement graphs?


It would be great if you can tell me! smile.gif
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post #2 of 31 Old 11-21-2012, 11:43 PM - Thread Starter
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No response? Come on - there has got to be something...?

The only more or less direct comparison I know of is Markus' comparison of XT vs. XT32:

XT
XT32
Left speaker + sub overlay

More or less - because unfortunately the "NO EQ" measurements differ.
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post #3 of 31 Old 11-22-2012, 03:15 AM
 
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funny..

nobody can own the perfect math equation installed inside the tool to get the job done.
because the correction requires math, and there is only one perfect solution.
close to perfect sounds the best, either direction from that point will grow worse.

therefore,
if those tools above arent perfect .. each one has limits and a point on the scale.
but the point on the scale might move as you change the room size or speaker distance through ALL possible values .. that is how you drain the list of programmed computer code from the library chip (memory).

so if you test each one once .. the distance away from perfect holds to the same percentage every single time?
does the same method always win over the other tools when the room size is different?

that means setting up the same speakers in like 12 different rooms
2-3ft distance difference is going to change the tone of the room where it rings (big chunks)
inches is going to target something small and ugly.
...and yet, distances more than 3-4ft could be highly regarded .. as well as the contents in the room that sicken the ringing echo of the room.

hard to find somebody that will go out there and move some speakers in all those rooms.
..again hard to find all those rooms to try it in.
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post #4 of 31 Old 11-22-2012, 03:34 AM - Thread Starter
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You are - of course - absolutely right, one room and speakersetting would not be enough to have a "definite" answer...

But I was thinking about rather big differences..
For example when I compared Advanced MCACC vs. XT32 the difference was so huge that I thought you have to see something like this in measurements, since MCACC did nothing about the standing waves in my room and XT32 basically "banned" them.
I noticed similar behaviour in several rooms - so I thought there has got to be a pattern.

Do you know what I mean?
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post #5 of 31 Old 11-22-2012, 04:54 AM
 
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i think what we see as communication is very small and lacking nutrition, as if dust confused as crumbs.

people arent sharing their results, not in picture or in words.
and to think, sometimes doing the right thing the first time .. and then using a second tool to do it right a second time , well it gives each tool a chance to show if it can do it's job twice or only once.


there are what? more than 1,000 people with automatic equalizer on the amplifier.
but nobody comes out and explains what they hear.
sure, people try to say what they heard ... but in the length of a single sentence up to something less than a paragraph, people leave the opportunity empty.. and that wound of emptiness causes the entire industry to be empty.

that is when places like this fill up with new borns asking questions of simple complexity .. and it drives away all the experienced users that are wanting to share experience or imagine and expand thought on creative new experiences.


i think there is only two questions:
1. how big of a chunk did it fix?
2. does it clamp down tight without any help?


anybody can ask a person working in a restraunt to wipe the table.
but that doesnt mean the person is going to wipe the entire table.
..and think about it, after taxes taken out .. the person is working there for what? $5-6 per hour ... doesnt get any attention or happiness from other people during the 8 hours they are there working .. and nothing to come home to except a need to cook and clean and get organized in the mind to fall asleep and do it all again the next day.

life has grown to be expected as that bad again.. where a person can do a single wipe of the table, make you angry because they didnt do it all, and then threaten your level of welcome if you choose to raise a complaint.
they didnt say something about just wiping it 5-10-15 minutes ago .. they just reach in to do 100% and come back with a smaller percentage, and because 100% is RARE people melt and give in ..keeping the thought in mind about being another person that isnt the only one not getting full 100%

and those small actions wont change until what?
the entire town needs to stop and stare at the person in trouble while people are pointing?
because nothing is going to stop that little bubble from floating away and doing it again until somebody helps break a pattern.
(ugly when you see breaking a pattern grow to become a pattern in & of itself)


i figure it goes like this..
you get what you get (and that could come with a knob to vary the final result depending on who deserves what)
or you get what you get and sue, then get some more and still be far from perfect because 'nobody is doing that' ...not 'you cant find anybody to care about the lacking value in your life that you stare at for a moment or off & on'

boiled down to somebody or some reason leading the way and the lead coming up short (like almost infinite resistance short)
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post #6 of 31 Old 11-22-2012, 08:25 AM
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Quote:
Originally Posted by jd17 View Post

Hey guys,

if something like this already exists - please forgive me. I did not find anything.

What I want to know - do we have a proper, objective comparison of (automatic) room correction results from different systems?
By that (proper, objective) I mean:

- one/same room for all compared systems
- same mic and speaker positions for all measurements (i.e. no changes to the room whatsoever)
- (indepenent) measurement before correction
- (indepenent) measurement after correction of each system

Interesting systems for comparison would be:

- Audyssey MultEQ XT
- Audyssey MultEQ XT32
- Anthem ARC
- Yamaha YPAO (RSC)
- Pioneer Advanced MCACC
- Trinnov

- Dirac
- Acourate
- Anti-Mode

- others



I'm sure someone has compared XT vs. XT32 like that some time... but what about the others? Do we have some data / measurement graphs?


It would be great if you can tell me! smile.gif

This is obviously a very complex area that should be evaluated by an unbiased, experienced reviewer with a proven track record. I know a few such people but so far I have not been able to interest any of them in a project like this.
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post #7 of 31 Old 11-22-2012, 09:22 AM
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Besides applying a parametric EQ to the subwoofer frequency, setting distance and gain for each channel... What does this "room correction" actually do?
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post #8 of 31 Old 11-22-2012, 12:24 PM
 
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it records an echo and makes it go away to whatever percentage below 100% was selected.

sometimes it will run a sound with all the frequencies in it and adjust the frequency tone controls to help smooth the frequency response.

the trick part is how long is the list of programmed instructions, how accurate is the list, and what order does the things on the list happen?


if you want to read more, go here:
http://www.avsforum.com/t/1433269/digital-room-correction-done-less-than-lazy
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post #9 of 31 Old 11-22-2012, 01:22 PM
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Of course the above post misstates things. Generally speaking, they all use a test tone and microphone to assess the actual in room frequency response of each speaker and apply equalization digitally (much more complex/detailed than typical equalizer controls) to achieve either flat response or a predetermined frequency response. Audyssey for example uses a tone that rises quickly from around 20 Hz to over 20 KHz, to each speaker separately, and then uses a fuzzy logic program to assess the corrections it should make based on multiple mic positions, then makes the corrections using thousands of finite impule response filters (much different from the infinite impulse response filters you see on treble and bass tone controls or parametric or graphic equalizers). Audyssey, based on its own research, defaults to a frequency response curve that rolls off in the highs. IDK what the others do specifically but the general concept os the same.
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post #10 of 31 Old 11-23-2012, 01:06 AM - Thread Starter
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Thank you for the answers!

Quote:
Originally Posted by arnyk View Post

This is obviously a very complex area that should be evaluated by an unbiased, experienced reviewer with a proven track record. I know a few such people but so far I have not been able to interest any of them in a project like this.
Unfortunately this is what I suspected.

Quote:
Originally Posted by JHAz 
Generally speaking, they all use a test tone and microphone to assess the actual in room frequency response of each speaker and apply equalization digitally (much more complex/detailed than typical equalizer controls) to achieve either flat response or a predetermined frequency response.
Exactly, and in my experience some are definitely more effective than others by doing so - at least if my ears were judging.

This is why I was interested in a more scientific comparison.
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post #11 of 31 Old 11-23-2012, 04:12 AM
 
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what is complex about it?'
i find it obnoxiously easy.

soundwaves look like peaks and dips.
those peaks and dips get recorded by the microphone.
that data hitting the microphone tells the computer to place the sample tap high or low (because of loud) and top or bottom (because of phase)

as the sample taps happen.. the line from left to right gets longer and longer.
the results recorded get flipped opposite and constantly applied to the audio data.

everybody on this forum talking about audio should know about hooking up the positive and negative wires backwards on one speaker .. because it causes the bass to cancel out (canceled decibels .. as well as canceled sound pressure level)


what do you think has happened the last 30 years with computer software?
sometimes not everything is 100% accurate.
they could take that line you recorded and adjust it (make it broken) on purpose .. and then make you pay more to get the program to stop adjusting it after it was recorded.
..other programs are accurate, but they are simply limited functionality.
typical limits..
bit depth (more chapters adding up for a stronger story)
bit rate (more paragraphs adding up to a chapter)


it doesnt strike me as odd to see one program cost $130
then another program doing the same thing with less limits for $600


whether those programs choose to shrink or expand those sample taps when they get adjusted.. that answer isnt important to me.
whether they are using each sample tap as a 'point' in the filter.. or if they are using every space inbetween those taps as a 'point' in the filter ... its an accuracy thing, its a room to fit thing.


maybe people need to know how to view the math.
the shape is squeezed and compressed tightly as if a piece of clay.
how does the squeezing and compression happen?
a huge pyramid.. like some cups stacked up on top of eachother.

those pyramids can 2 or 4
2 = only one up or down
4 = two up or downs (one for amplitude and one for phase)


quoted from here: http://www.dspguru.com/dsp/faqs/fir/basics

'A FIR "tap" is simply a coefficient/delay pair. The number of FIR taps, (often designated as "N") is an indication of 1) the amount of memory required to implement the filter, 2) the number of calculations required, and 3) the amount of "filtering" the filter can do; in effect, more taps means more stopband attenuation, less ripple, narrower filters, etc.'

so if you start with a single shape like this /
you would see that is the tip of the pyramid.
all the bricks below helped 'nudge' or 'squeeze' the shape to become what it is at the top.


...i know
many people dont realize it is possible to do math by trimming or adding to a shape.

but think of this..
if you record with the microphone, you are laying down a line that is a shape.
if your filter doesnt have enough taps.. then the entire percentage of the recording wont make it to the final result and the correction will be less.


if the operating system works on a limited number of taps ... then the convolution filter doesnt get to pick how the trim happens.
nope..
the program that recorded the impulse response will do it
or
the program that you use to edit and save the impulse response file will do it.

chances are..
the program you used to record the impulse response file has to be responsible enough to step in and take action to gather the necessary data.. it keeps the final result high quality.
because the audio editing program might not have a list of what is and isnt important ... having that list of prioritized data value will keep the trimmed final results sounding as best as possible.


i think every time people communicate .... it is always a chance to stay stuck in the mono lifestyle you are in, or expand your list of interest and value.
often times too much effort goes towards allowing people to do one thing their whole life, which really disables them and cuts freedom short (or even takes it away).
yesterday i was thinking about how a cab driver sits in a vehicle and drives around in a car every single day .. and that person might do that job from the time they are 20 years old up until they retire at age 70 or 80 .. and then dead 5-10 years after that.

think about it..
if that person comes back to life, they've got a whole lifetime of being involved with people out there on the street (think of it as a library of evidence)
..if that person doesnt come back to life, they had a whole lifetime of repeating the same electricity day after day as if there isnt thousands of electrical situations existing on this planet every single day.

some people like to ignore the long list.
other people enjoy life for what it is in all of its complexity as they work to embrace it rather than ignore or hide from it.



you want a shorter version of how the correction works?
setup a microphone
use audio recording software to record a sine sweep
take the recording into the audio editor to trim the empty from the front, then inverse the file and save it.
run the file through the convolver.



want to know how it works in a different area?
the lines of audio data come pouring down like any of the dots you see in the video game 'guitar hero'
the filter is the line of buttons on the bottom.
when the treadmill of dots passes the main line of dots on the bottom ... the dot will change as it goes by.

you could say the filter is changing every single dot as it passes .. just like a factory pours chocolate over every single nut as it passes by (to put the nut inside the candy)
or
call it painted instead of chocolate



you want to think of it more hard?
look at a list of numbers 0 - 9
if you've got a number on the dot as it is traveling towards the filter ...... then the filter says 'each 50hz tone gets an automatic 3 added to it'
talking about binary.. those numbers can go above 9
so if the music said the data value is 9 .. and the filter said everything right there gets a 3 ... then the soundcard is going to see a 12


there..
basics for recording the impulse, analyzing the impulse (limits included), and applying the filter to the stream of audio data


the math has been translated, i'm not going to sour myself because i didnt hand over a bunch of visual math symbols.
(but if people continue to drag eachother's energy down .... there wont be enough energy to listen to people that translate the math)
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post #12 of 31 Old 11-23-2012, 05:21 AM
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So easy that all companies hired a couple of high school drop-outs to create programs to deal with this. No where as easy as you think

Life is enjoyable with good quality
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post #13 of 31 Old 11-23-2012, 05:27 AM
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This maybe of interest to you:

The Subjective and Objective Evaluation of Room Correction Products

Frank


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post #14 of 31 Old 11-23-2012, 05:33 AM - Thread Starter
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Quote:
Originally Posted by fabulousfrankie View Post

This maybe of interest to you:
The Subjective and Objective Evaluation of Room Correction Products
Frank
Thank you for the link - which of course I already know. smile.gif

Unfortunately the systems are not named and as far as I got it - none of the above mentioned systems is part of the trial.
Audyssey apparently was represented, but with an older / less sophisticated system? (MultEQ)?

Correct me if I am wrong here. It's been a while since I read this one.
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post #15 of 31 Old 11-23-2012, 05:49 AM
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Room Correction I believe is a band aid to some issues that maybe one can't correct. But the real way to get a room to sound good is not with a Room correction system. It's better to actually treat the room. No program can substitute for treatments.
Most people do not have a dedicated room to set up properly so companies like Integra , Yamaha , Pioneer etc all offer these Room correction system to "HELP" get closer to a flat response. None of them can fully correct a room.

Another thing to think about is speaker placement. Getting that right in the given room or at least as close to as possible to spec will yield greater results then a Room correction system.

I gotta agree with most of the posts before me that there really isn't a way to determine which correction system is best. Yeah many claim theirs is best for all these reasons but think about it. Test this system on a given speaker system and room , then now go to a totally different room with different problems and a totally different speaker package. What about proper speaker placement? How good are the speakers being used in the roles they where put in? The amp driving them , is it powerful enough to get to reference levels in this room without falling apart?

Seating? What about where the seats are , how does that effect this room correction system. Some want 3 to 7 different points , some only want 1. Who is right? What is the goal of this question?

What if the best proven correction system is in a preamp or receiver that doesn't sound good with the speakers YOU like? Then what?

Amazing how many questions can be asked with only one wanting an answer for. In my professional opinion I think all correction systems offer a better experience then no correction. Bose and Pioneer basically had it first if you exclude JBL synthesis . I think they may have introduced it before anyone else if my memory serves me. I think if one seeks this answer , one has to plan the entire job around this. Find what works best with given "BEST" correction system. What room size does this system work it's best in , what speakers perform best when corrected with given BEST system.

Good question.
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post #16 of 31 Old 11-23-2012, 06:07 AM - Thread Starter
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I'm starting to feel a bit misunderstood here...

I do not mean to have a "best" getting out of this thread or something like that.
Also I know that no system can fully replace "proper room treatment".

I just would like to see, what measurements under stated conditions would look like and what the differences between the results are.

Quote:
In my professional opinion I think all correction systems offer a better experience then no correction.
This is where I would strongly disagree. Some results of room correction systems I listened to, just sounded much worse than listening to a "direct" signal. But this - of course - is subjective.
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post #17 of 31 Old 11-23-2012, 06:20 AM
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Quote:
Originally Posted by jd17 View Post

I'm starting to feel a bit misunderstood here...
I do not mean to have a "best" getting out of this thread or something like that.
Also I know that no system can fully replace "proper room treatment".
I just would like to see, what measurements under stated conditions would look like and what the differences between the results are.
This is where I would strongly disagree. Some results of room correction systems I listened to, just sounded much worse than listening to a "direct" signal. But this - of course - is subjective.

Like any technology, end users can make a mess of the implementation, usually by not following instructions on how utilize the tool.

That's not to say that rooms don't exist where room EQ doesn't work properly, but those are likely very few and far between.
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post #18 of 31 Old 11-23-2012, 06:35 AM - Thread Starter
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Quote:
Originally Posted by bfreedma View Post

Like any technology, end users can make a mess of the implementation, usually by not following instructions on how utilize the tool.
That's not to say that rooms don't exist where room EQ doesn't work properly, but those are likely very few and far between.
Again - even if this was the case - it would not matter in the comparison I am looking for, right?
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post #19 of 31 Old 11-23-2012, 07:29 AM
 
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Quote:
Originally Posted by jd17 View Post

I'm starting to feel a bit misunderstood here...
I do not mean to have a "best" getting out of this thread or something like that.
Also I know that no system can fully replace "proper room treatment".
I just would like to see, what measurements under stated conditions would look like and what the differences between the results are.
This is where I would strongly disagree. Some results of room correction systems I listened to, just sounded much worse than listening to a "direct" signal. But this - of course - is subjective.


um..
we are going to die as a species if you dont realize an engine needs seals and lubrication to work.
you are totally going to miss out on at least 100 years of industrial work .. and all that experience is simply going to be the new next door neighbor nobody knows.
valuable = you can trade life for it

some give it away for free .. some sit and wait for somebody with something (else) to trade.

since what?
when cars were born?
people had sat around doing nothing more than calibrating something to make it better and better until they ran into a wall with nothing more to be done.
engines were built .. electrical grids were installed and made efficient .. telephones were invented .. television was invented along with projectors.

before that was chemistry.
people would use their scopes to write down as much information as possible about the ingrediants at the end of the scope.
they would travel around the world to learn about new ingrediants .. they would share with people around the world to also exchange information
back then it was nothing but calibration after calibration.
if you werent calibrating the ingrediants .. you were using those ingrediants to calibrate something (or somebody).


i think the only big thing to reveal is if one of the programs always leaves big peaks and dips .. and then avoid that one.
because it always boils down to this..
they are more than 'in style' because people have reported that there was an improvement.
okay.. there is more than one or two or three people doing it.. and that means the industry wants us to have it.
if you dont want to sit down and learn egg-zap-ly how it works to build a bigger and better one .. then you are simply going to go out there and grab one off the shelf and use it like a napkin.

they know people are going to wonder which one works better than the other.
and if they let that information out.. the program doing the least improvement already knows their future is in trouble because their quality isnt high.
they already know if they are smart enough to do it better a second time or if they will go bankrupt.
it is just a bunch of overly advanced village people that try to get in there and say they will keep it going for 10 years and make people wait for the next big wave of upgrades.


...maybe we should stop viewing life like audio is one of the 5 hobbies we are allowed to involve ourselves with in a single lifetime.. because there is more to do and enjoy in a single day .. but the brainwashing and the hiding and the wasting opportunity to communicate happens over there in those hobbies too.
and maybe those people dont get to play with those toys as often as people can play with audio.
i think anybody running around with a single pacifier or baby bottle is going to be at a large risk when somebody takes that thing away.
the happy kid has options (something else to grab while they wait for it to come back).



but what i really wanted to post about..
if the room correction makes things worse, then the speakers were already with a flat frequency response and the target curve of the program made it worse.
i've seen $300,000 speaker systems that were nothing more than pieces that fit into the room and they didnt need much of anything to finish the final result.
sure.. spend $299,999 more than you need to because it is almost perfect in frequency response when you open the box.
pretty soon the speaker manufacturers are going to need to ask you how big the room is so they can build you some custom voice coils to match the room echo.
(or you pay them all that money and they dont tell you how they learned what the room size is)


but many times people dont calibrate anything.
they dont keep their bicycle handle bars tight
they dont keep their bicycle seat straight and tight
they dont keep their bicycle chain tight
they dont keep their brake cables tight

there is that sticky thought 'it worked yesterday.. it should be good today'
or
'somebody handed it to me and that person wouldnt put themselves in danger'

we learn all the well ... the 'wouldnt put themselves in danger' part is when the store owner says they dont care about the customer and they dont care about what is on the store shelves because nobody forced the customer to buy what they did.
the person hosting the time doesnt take responsibility and tries to place the blame on the other people who helped make a hosted event possible.
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post #20 of 31 Old 11-23-2012, 07:33 AM
 
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Quote:
Originally Posted by jd17 View Post

Again - even if this was the case - it would not matter in the comparison I am looking for, right?

really..
it shouldnt matter because any technology exists because it is perfect math.
they start you off at some percentage and milk it's way up to 100% ... because after 100% there is no going back.
how slow to wait ... how much of an increase will the next one be .. how far away from 100% you really are .. if there is more math to it than what you are using .. will something else come along and make it more of a problem than a tool
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post #21 of 31 Old 11-23-2012, 07:53 AM
 
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That study is an interesting read but not necessarily a fair comparison. There is no doubt that a properly set up room is the best place to start. If you can place your seating, speakers, subs and acoustic treatments properly little EQ will be required and would be the final tweak and it would be real easy to do more damage with EQ than none at all. No amount of equalization can correct for poor placement and a bad room. No matter what EQ you use in a racquetball court it is still going to sound like a racquetball court. Can EQ improve the sound? Certainly! But, don't expect miracles.

As we move these EQ systems to more real world rooms the results vary. Each of the EQ systems you are comparing may or may not improve the sound. One might do better in one room while another does a better job in a different room. Their simple algorithms can't compete with a competent calibrator which will spend hours to days calibrating a room and take a lot more measurements than these simple systems do.

It doesn't matter which one is technically superior, has more filters, adjusts phase, uses a different filter type (FIR vs. IIR), etc. They may or may not improve your room. Often good measurements and a few simple parametric EQ filters will do a better job but you have to know what to EQ and what to leave alone, this can't be done in a 10 minute auto EQ. Making everything flat or to a given curve is not always the best solution. It is the implementation not the technical prowess of these which will affect a given room. All these EQs have different algorithms and any given one might not be the best solutions for your room. You can easily find many threads where people preferred their system with the EQ off.

I will make one comment on the EQs mentioned and that is Trinnov. None of the other systems do what Trinnov does and that is its remapping feature. Although Trinnov does EQ as well, none of the others do remapping and moves the progam sound between speakers to give a more accurate soundstage and presentation. If you don't have good speaker placement this might certainly help.
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post #22 of 31 Old 11-23-2012, 08:27 AM
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This maybe of interest to you:
The Subjective and Objective Evaluation of Room Correction Products
Frank
Thank you for the link - which of course I already know. smile.gif

Unfortunately the systems are not named and as far as I got it - none of the above mentioned systems is part of the trial.
Audyssey apparently was represented, but with an older / less sophisticated system? (MultEQ)?

Correct me if I am wrong here. It's been a while since I read this one.

The Audyssey system was their standalone box, with MultEQ XT. And the other systems are now known: RoomPerfect was #3, ARC #5, and Audyssey last.
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That study is an interesting read but not necessarily a fair comparison.

Why not? It shows that all the systems do basically as intended: they EQ even a fairly crappy speaker (such as the B&W N802 they used) to a specific target curve. Thing is, target curves that don't account for the natural swell of bass in a small room seem to be not preferred to curves that tilt a bit. (ARC would probably do much better today, because now they don't try to slap down room gain.)

Also, target curves that introduce a crappy speakers compensation notch in the midrange don't seem to do as well as curves that leave the midrange alone, even on a crappy speaker like the N802.

So, it seems that the main thing with RC, assuming competent setup, is the actual target curve of the system.
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I will make one comment on the EQs mentioned and that is Trinnov. None of the other systems do what Trinnov does and that is its remapping feature. Although Trinnov does EQ as well, none of the others do remapping and moves the progam sound between speakers to give a more accurate soundstage and presentation. If you don't have good speaker placement this might certainly help.

In a fairly small area, yes. Move far from that and you hear odd noises from the closer speakers. That seems basically inevitable, though, given that all the speakers in a system are used to move the sound a certain way at a certain spot in the room.

(As for this thread, I have AVR's with the two best room correction systems that have been made available in AVR's - ARC and Trinnov - and I do plan on doing comparative measurements of one speaker after implementation on each when I get the time. Haven't had the time yet, though. Perhaps during the holidays, or early next year. I used to have two MultEQ XT boxes, but one died and I sold the other after I heard the midrange improvement ARC offered over Audyssey's crappy speakers compensation notch.)

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post #23 of 31 Old 11-23-2012, 08:40 AM
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Again - even if this was the case - it would not matter in the comparison I am looking for, right?

No, it wouldn't matter, but as you suggest in your first post, unless the systems are implemented correctly by the user, the results won't help define which EQ may be better.. The bigger question may be around how each system will react to a given room and whether the results are consistent across multiple rooms/scenarios.
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post #24 of 31 Old 11-23-2012, 12:19 PM
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ARC would probably do much better today, because now they don't try to slap down room gain.

??

Room gain, which has been a part of ARC since it was created, is described in the oldest ARC literature and manuals complete with graph. It's evidently one of the things that ARC brought into RC users' collective consciousness in light of how often I had to answer inquiries over it during ARC's first year on the market and explain that the hump in the target graph wasn't some artificial loudness curve.

ARC works better today because between v1, which the study used, and v3 many people sent us measurement files showing odd situations. They've all been addressed, and the room gain algorithm had almost nothing to do with it - it used to go to 6 dB but its limit was lowered to 4 dB as of v2. That's it. Somewhere along the line some AVSers posted their results in the Anthem threads wondering why their room gain showed up as 0, but the reason in all of those cases was merely that they were using they were using lots of bass traps or speakers that don't play much bass. ARC version makes no difference in such a case.

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I'm saying it is not a fair comparison because of the room they were doing this in. It gives an idea of what some of these systems can do and how they do it. A better comparison would be to do objective and subjective testing in many different rooms and see what the resultsyield. Using a very well set up room with acoustic treatments is not what many people have in their homes. Some enthusiasts on this site do but in general not the average user.

Many EQ systems don't know if they are EQing the room or the speaker but that doesn't mean their algorithm is bad. If they developed their algorithm in similar situations to the one measured it may give great results. No one EQ system is going to work best in all situations. It would be interesting to know which one improves sound in the majority of situations but that would be a big undertaking.

On Trinnov of course it works best for the money seat. That is pretty much true even without EQ. Simple physics tells us we can't precisely set levels and delays for multiple locations nevermind EQ.
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post #26 of 31 Old 11-23-2012, 07:31 PM
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I think the first place to start is simply looking at the goal/target curve as they are pretty different for each manufacturer.  

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post #27 of 31 Old 11-23-2012, 07:52 PM
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I think the first place to start is simply looking at the goal/target curve as they are pretty different for each manufacturer.  
Some of these - Trinnov PRO units, for example - have no default target curve, and one (or more) must be designed by the user. DEQX' HDP preamp solution corrects the measured response by making maximum +- 3dB corrections to "linearize" that response. No target is used or required.
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post #28 of 31 Old 11-24-2012, 04:14 PM
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ARC would probably do much better today, because now they don't try to slap down room gain.

??

Room gain, which has been a part of ARC since it was created, is described in the oldest ARC literature and manuals complete with graph.

Interesting. The main reason I see why ARC came in basically in a dead heat with "no RC" (as compared to Audyssey, which came in at "worse than no RC," and the two Harman solutions and RoomPerfect, which both came in ahead of "no RC) is that the ARC curves don't show much room gain. (Audyssey completely kills it, along with adding their crappy speakers midrange compensation notch.)

That's actually why I assumed the 3d-place RoomPerfect curve was actually ARC's, until someone who had toured the Harman facility told me otherwise.

I do think that, in the "expensive but reasonable" section of the market (i.e. under say 2k-2500 USD) ARC makes your MRX receivers the current best-in-class, without much competition. If Sherwood had ironed all the bugs out of the R-972 and maybe updated it with a variant of Anthem's best feature (Quick Measure) and whatever new video whatever, it would be a two-horse race. ARC still doesn't get subs-mains integration quite right (Trinnov is uniquely good in my experience there, and Audyssey is worse than ARC) but it's overall a great system.

And it utterly amazes me that everyone else hasn't tried to rip off Quick Measure yet. That is an inspired stroke of genius.
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I think the first place to start is simply looking at the goal/target curve as they are pretty different for each manufacturer.

Yes. The systems seem to have progressed to a point where in most rooms with most speakers, a careful user can get the system to its desired target curve.
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***DEQX' HDP preamp solution corrects the measured response by making maximum +- 3dB corrections to "linearize" that response. No target is used or required.

"Flat line" is a target curve as well. So is "what this system basically already does, with some smoothing."

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post #29 of 31 Old 11-24-2012, 04:56 PM
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***DEQX' HDP preamp solution corrects the measured response by making maximum +- 3dB corrections to "linearize" that response. No target is used or required.

"Flat line" is a target curve as well. So is "what this system basically already does, with some smoothing."
The DEQX does not correct to a "flat line". It applies up to +-3dB filters to smooth the measured response and the resultant "curve" is entirely dependent upon that inital, measured response. This is very different from systems which measure the response, compare to a target, and then apply filters in an effort to create a resultant response which conforms to the target.
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***DEQX' HDP preamp solution corrects the measured response by making maximum +- 3dB corrections to "linearize" that response. No target is used or required.

"Flat line" is a target curve as well. So is "what this system basically already does, with some smoothing."
The DEQX does not correct to a "flat line". It applies up to +-3dB filters to smooth the measured response and the resultant "curve" is entirely dependent upon that inital, measured response. This is very different from systems which measure the response, compare to a target, and then apply filters in an effort to create a resultant response which conforms to the target.

Please re-read what you've quoted. What you wrote could have been more pithily described as "what this system basically already does, with some smoothing." Seems like those words might have appeared above.

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