I just really wish there was a way for you guys to try it for yourselves just to see how it works in your realms without springing for it cash wise.

I'd be satisfied if any disinterested third party published a detailed evaluation. But I have looked and so far I have found only magazine reviews that either paraphrase IK's marketing literature or add their own indefensible embellishments (example:"why struggle with egg boxes and bass traps when there's another way!" Aargh.) . If such an evaluation exists, IK neither quotes it nor links to it.

There have been some AES papers on the subject of room correction, but I am not an AES member and therefore do not have access to them (unless I want to buy them at 20 bucks a pop). Examples: http://www.aes.org/events/123/papers/session.cfm?code=P16

One of the few references I was able to access is a lecture presented by the CTO of Lyngdorf Audio, which sells a room-correction product called RoomPerfect. It's a real gem. Here is the lecture, and here are the accompanying slides. Be sure to get the slides, as an audio lecture is hard to follow without visual aids. Also be sure to listen to the entire lecture (over an hour), as the answers to many nagging questions are given toward the end.

Although this speaker's impartiality might be questioned, given that the he works for a room-correction vendor, the presenter is a legitimate expert (in both acoustics and DSP) and the audience is a group of AES members, presumably a knowledgeable and skeptical crowd. (His company's product lists for $3,800, making ARC a bargain by comparison)

If nothing else, Mr. Pedersen's lecture offers a good argument for the importance of speaker placement. But it also explains the logic behind multiple measurement positions (minimum of 4, one of which is the listening position, 9 positions recommended).

Interestingly, his approach requires measurements in random positions and with random microphone orientation, unlike IK's method, which uses very specific positions. As expected, the slides reveal that sound pressure levels can vary by 30-40db at different points in the room. Like with ARC, he is averaging the sound pressure measurements to form the basis for an equalization curve.

The key to the system is setting gain limits based on the room's profile (based on average SPL readings). The EQ profile is then constrained by these gain limits. This turns out to be the answer to the "how do you fix a null?" question - you don't try.

Note that the ultimate goal is optimizing the listening (mix) position, acknowledging that it's not "room" correction, but rather "listening position" correction.

But at no point does the presenter show anything like the ruler-flat response shown on the ARC display. In fact, he criticizes vendors who claim to be able to get such a flat result.

Hi Danny

I think if you read my post that describes my process for measuring you'll realize that I actually unpackaged ARC and set to do an initial run through following the instructions one step at a time. Just get the box open, install the software etc and get going. My measurement were pretty rough. I was simply trying to complete a full and minimum measurement cycle to get a response curve saved fro reference later on as I developed an idea of what I was actually doing.

This was the one and only measurement I had taken. I used visual cues in my room to find centers and whilst I tried to get pretty accurate I wouldn't say that the 14 measurements I made were perfectly symmetrical so I fully understand the limitations of what i had done. To make more precise measurements to get perfect symmetry in mic placement I'll need to move quite a bit of stuff around in my room to access walls at floor level etc for precise measuring. Not anything I've had time to do since those initial tests and what I thought was pretty clearly just my initial impressions of the ARC system.

On the whole my results in terms of the audio I heard before and after ARC was that they were so encouraging that I want to spend more time but that needs to be contiguous time say a whole morning or afternoon, even a whole day to get an absolutely perfect reading.

As my room is a rectangular prism with much stuff around the perimeter its going to take me a while to get things sorted out. My speakers are wall mounted on steel brackets that provide very good disconnection from the wall but are a little closer to the wall than I'd like. For me ARC was never going to be a complete solution. It was part of a much bigger picture in my mind but at the price I paid for it, I'll mention again that it was the single most significant step fo a given amount of improvement in sound quality that I' have done with my current setup.

Its all just a long road that I'm part way down. I never thought this thread was going to go on for so long. In fact I debated with myself whether I was even going to bother with another post but here I am. So when i get the time I'll do some more but in the meantime life beckons as do other things.

See you round like a rissole.

ORIGINAL: mudgel

Hi Danny

I think if you read my post that describes my process for measuring you'll realize that I actually unpackaged ARC and set to do an initial run through following the instructions one step at a time. Just get the box open, install the software etc and get going. My measurement were pretty rough. I was simply trying to complete a full and minimum measurement cycle to get a response curve saved fro reference later on as I developed an idea of what I was actually doing.

This was the one and only measurement I had taken. I used visual cues in my room to find centers and whilst I tried to get pretty accurate I wouldn't say that the 14 measurements I made were perfectly symmetrical so I fully understand the limitations of what i had done. To make more precise measurements to get perfect symmetry in mic placement I'll need to move quite a bit of stuff around in my room to access walls at floor level etc for precise measuring. Not anything I've had time to do since those initial tests and what I thought was pretty clearly just my initial impressions of the ARC system.

On the whole my results in terms of the audio I heard before and after ARC was that they were so encouraging that I want to spend more time but that needs to be contiguous time say a whole morning or afternoon, even a whole day to get an absolutely perfect reading.

As my room is a rectangular prism with much stuff around the perimeter its going to take me a while to get things sorted out. My speakers are wall mounted on steel brackets that provide very good disconnection from the wall but are a little closer to the wall than I'd like. For me ARC was never going to be a complete solution. It was part of a much bigger picture in my mind but at the price I paid for it, I'll mention again that it was the single most significant step fo a given amount of improvement in sound quality that I' have done with my current setup.

Its all just a long road that I'm part way down. I never thought this thread was going to go on for so long. In fact I debated with myself whether I was even going to bother with another post but here I am. So when i get the time I'll do some more but in the meantime life beckons as do other things.

See you round like a rissole.

Hi Mike,

Yeah I read the post and completely understand what and why you did what you did. I did the exact same thing as you with the one screen shot you saw of mine. All by eye and I used "landmarks" in my room. You just wait until you can get some time to really do this thing right. It should take you about 30 minutes to map out your placements and 35-40 on the nose to do the actual measurements. Another thing I picked up on from a few users that had experienced "phasing".

When they did the mic corrections, they forgot to kill the mic from re-sending the sound. LOL! So the chirp from ARC was coming out and feeding into the mic, and the mic was literally in monitor mode at the time. So it was dual feeding it back in. Not sure if you're aware of this possibility, but if you aren't I figured I'd pass it on to you. Make sure you save that current curve you have so you can compare it to the new one you make when you get time. Just so you can literally hear how much of a difference it makes when you go through the pains of hell to get all your measurements accurate. I know the thing isn't the be all end all to room issues....but man, it sure has made an incredible difference for me and many others that have used it right. Good luck!

∞

ORIGINAL: bitflipper

I just really wish there was a way for you guys to try it for yourselves just to see how it works in your realms without springing for it cash wise.

I'd be satisfied if any disinterested third party published a detailed evaluation. But I have looked and so far I have found only magazine reviews that either paraphrase IK's marketing literature or add their own indefensible embellishments (example:"why struggle with egg boxes and bass traps when there's another way!" Aargh.) . If such an evaluation exists, IK neither quotes it nor links to it.

There have been some AES papers on the subject of room correction, but I am not an AES member and therefore do not have access to them (unless I want to buy them at 20 bucks a pop). Examples: http://www.aes.org/events/123/papers/session.cfm?code=P16

One of the few references I was able to access is a lecture presented by the CTO of Lyngdorf Audio, which sells a room-correction product called RoomPerfect. It's a real gem. Here is the lecture, and here are the accompanying slides. Be sure to get the slides, as an audio lecture is hard to follow without visual aids. Also be sure to listen to the entire lecture (over an hour), as the answers to many nagging questions are given toward the end.

Although this speaker's impartiality might be questioned, given that the he works for a room-correction vendor, the presenter is a legitimate expert (in both acoustics and DSP) and the audience is a group of AES members, presumably a knowledgeable and skeptical crowd. (His company's product lists for $3,800, making ARC a bargain by comparison)

If nothing else, Mr. Pedersen's lecture offers a good argument for the importance of speaker placement. But it also explains the logic behind multiple measurement positions (minimum of 4, one of which is the listening position, 9 positions recommended).

Interestingly, his approach requires measurements in random positions and with random microphone orientation, unlike IK's method, which uses very specific positions. As expected, the slides reveal that sound pressure levels can vary by 30-40db at different points in the room. Like with ARC, he is averaging the sound pressure measurements to form the basis for an equalization curve.

The key to the system is setting gain limits based on the room's profile (based on average SPL readings). The EQ profile is then constrained by these gain limits. This turns out to be the answer to the "how do you fix a null?" question - you don't try.

Note that the ultimate goal is optimizing the listening (mix) position, acknowledging that it's not "room" correction, but rather "listening position" correction.

But at no point does the presenter show anything like the ruler-flat response shown on the ARC display. In fact, he criticizes vendors who claim to be able to get such a flat result.

Some good reading there Bit, thanks for sharing it! That of course goes a bit beyond my intelligence for this sort of thing, but it was way informative for sure! I'm just one of those guys that looks at things as "ok, this supposedly works...lets try it", it if works, I'm in good shape and I'll brag about it. If it sucks, I'll bash it into the ground and tell everyone not to waste their money. The bottom line in my humble opinion is this...

If you or someone else is constantly messing with eq's in a mix and you're not down with some of that ugly room decor stuff...this little gem makes a huge difference and if you move your gear, all you have to do is take some new measurements. It even helps monitors that are not very good to sound flatter. If you are not having any problems with your mixes and you never second guess yourself, this thing probably will make matters worse for you because you will have to relearn what your monitors sound like while using it. I was so bad with my setup, I was seriously ready to just give up. I've been engineering for a very long time and always felt though I knew the talk and practiced all the right starting points while keeping myself focused, I still sounded like a n00b in certain areas. It was actually demoralizing to be honest. I really took it to heart. Granted, I have NEVER expected to crank out major label sounding stuff, but it really is disheartening when you can't even at least *somewhat* come close, ya know? I know the cards are against us....some of us are not specialists in the field, and we can't compare our thousands of dollars in gear vs major label millions with producers, engineers and pro mastering guys. But, we should still be able to come close or at least have a product we are happy with at the end of the day. I've never been happy with a single recording I've ever created or mixed until ARC came around. I know, that sounds like a blatant ad for them....but I'm really being serious. It was quite refreshing to know that I really wasn't a crap engineer and my issue was I was not hearing the correct stuff to make the right calls, ya know?

So look at it this way...if you have any of those issues, try it out. If it fails, maybe it just wasn't for you and I'm sure someone would buy it off you that it may work for. I would just like to see how those that said it failed, measured their rooms. I'd be willing to bet they did not go through the steps that I, Billy Buck and others used to make this thing worth bragging about. Trust me, I was skeptical also at first. As a matter of fact, after my first correction I looked at myself and said "you dumbass, you wasted another $499 on another hyped piece of gear". But, I'm one of those guys that tries to exhaust something to the fullest before I give up on it and I'm glad I did because once I got this thing tweaked the right way, the differences in my mixes were just astonishing to me. As a matter of fact, one of my friends who I consider a guru has always been tough on me when I have emailed him a tune or brought him a cd to listen to in person.

So much so, he'd stop the cd in 5 seconds and say "dude, this sounds like azz"....hand me a pen and paper and say "listen to this and write down all the stuff you think is wrong with it." After I was done listening and writing it all down, he'd say "ok, if you can hear all this stuff here, why can't you hear it at your place? Right Danny....LIKE I'VE BEEN TELLING YOU FOR YEARS, YOU NEED ROOM CORRECTION!!!!" He went on to tell me that I'd NEVER be able to hear what I'm supposed to hear with the way my room is set up as well as using the first generation NS-10's. My monitors were too close to the wall, I had 0 bass response so I kept on adding it in till it sounded like enough...and I was just a mess. So, I thought new monitors would help. I bought the Adams and though they helped a lot, I was still missing things. When I got ARC and used it, I brough that same guy a mix of a tune and the first thing he said was "ok, who did you have mix this?" LOL!! It was then that he asked me to ARC his room...and he's the dude with the 2 mill studio I mentioned in another post.

We can analyze the thing like mad....or we can say screw it, give it a shot and see what it does. But only if you are having mix issues and you find yourself frustrated. If it doesn't work, you know you tried it and gave it an honest shot. Just sell it off. It WILL work for someone, that's for sure. :)

ORIGINAL: mike_mccue

Danny,

Is the Arc test tone a chirp rather than pink noise? I assumed the multiple "samples" were made while the room was loaded.

This is curious to me because the RTA work I am familiar with is done with a "loaded" room. The pink noise is played for several minutes to allow the energy to reach what ever balance it can before an observation is made.

I can imagine how a chirp could isolate the response from the speaker from that of the room. It's an interesting concept.

Any thoughts on this?

best,
mike

Mike, it sounds like a house alarm. Kinda like a Bweep Bweep Bweep kinda thing. It does it in the left speaker a few times, then it does it in the right speaker. It's a very nasty sound that would defintely make the perfect car/house alarm because it's so annoying. LOL!! As a matter of fact, you can literally feel your eardrums flexing when it hits. You don't make it very loud...only loud enough to where you see the proper signal within the software. But even there, I have to hold my ears because it really hits you deep in your eardrums. It's something in the low end part of the pulse that gets to me. The high end isn't so bad....the only way I can descibe it is...picture speakers flapping where you see them moving. This is what my eardrums feel like when it chirps. LOL!!

∞

It's a very fast tone oscillator sweeping from low to high in less than a second, unlike pink noise that hits all at once. It takes ten pulses (for lack of a better term) per side....then you move to the next position. Most of what I've read on this thread deals with E.Q., but if I'm not mistaken Arc deals with time alignment also. If it only adjusted E.Q. like an RTA then it would be acting as a basic RTA. I would imagine there is some delay mojo happening along with the E.Q. adjustments, somehow dealing with standing waves, comb filtering, flutter echo, ect. in a determined position ie. in your sweet spot. Hence the importance of mic placement when measuring. It probably delays very specific frequencies to arrive coherently, and at a flat frequency response. This is just an opinion on my part.
Whatever it does, it works great.

Maybe you guys can help me understand this thing. I've been mixing a track all day. I get it sounding great on my computer (near field monitors), burn it, run to the living room stereo, then to the car and it sounds like crap. Full of mid range mud with no crisp highs.  Knowing this, I finally mixed it on the computer with the high end burning my ears with sizzle and taking out so much mid that it was completely void. Then I burnt it and it sounded not bad in the car or home stereo.
 
Here's my question.
 
The ARC basically EQ's my system to make it flat. I imagine the graph will show a bunch of mid range has been removed around 200-300 hz. (Looking at ARC screen shots, this is what I mostly see). With the ARC engaged, I now mix the project to my liking, disengage ARC and burn it. What I don't understand is that ARC will remove all that mid range mud while I'm mixing, I end up with the sound I like which means probably adding some mid range. When I then disengage and burn it, won't I be adding even more mid than if I hadn't used ARC at all?
 
I'm confused.

Wash, it's just the opposite. If you are mixing in too much mids, that's because you're room is hiding them. ARC will add them in, not take them away which will allow you to mix "mid light" instead of loaded with mids. It adds all the stuff you are missing and takes away all the stuff that makes your room and monitors a nightmare. So when you mix, you're mixing what you should hear. When you turn ARC off and export, it should sound great everywhere.

For example, I had a lack of bass issue in my room. So everything I mixed was bass heavy. Once ARC was running and set up correctly, it put the bass in automatically that I was missing, thus it allowed me to mix "bass lighter" in my mixes. I also had a bit of a mid range problem where I had too much in my mixes....ARC compensated for that and added it to my monitors so when I'd mix, I'd not use as much mids. It's really an amazing little tool, I can't stress that enough. I've turned it on to several people and not one has experienced any issues at all other than getting the mic procedure down correctly. That's the hardest part really. But other than that, like I've said many times before, it's saved my life as far as how I love the recording field once again. Best of luck to you....I hope this helps.