# FORUM WARNING. PINK NOISE!



## Drop11 (Jul 4, 2016)

I've been having issues with my system for a good while now.

It wasn't my truck. It wasnt the quality of my equipment. It had nothing to do with my tuning ability.

It was the ****ing pink noise I was using.
The sound was always thin and harsh and heavy in the sub bass. 

I've tuned for almost a year now using pink noise that was absolute garbage.

For those of you out there trying to tune with pink noise and not getting good results make sure you are using quality pink noise from a verified solid source.

I almost cried when I loaded the new file and heard how much different it was from what I had been tuning with. I'm sure some of you can imagine the frustration.

Im currently running the focal utopias on a focal fps 4160 and a jl w6 12 on a focal fps 3000.

It seemed no matter what I did I couldn't make it sound good. It made no damn sense and now I know why.
At least I finally found the issue. Hopefully this thread will help others.


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## SkizeR (Apr 19, 2011)

try using rew sweeps instead. more consistent. i tried it recently and its quicker and easier and have slightly better results so far


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## Drop11 (Jul 4, 2016)

I will for verification. My pink noise file comes from a pro audio manufacturer. It's the real deal but I'm all about verifying now with multiple sources. It's damn shame. You can't imagine how much time I've wasted.


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## SkizeR (Apr 19, 2011)

oh yes i can lol


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## ndm (Jul 5, 2007)

Drop11 said:


> I will for verification. My pink noise file comes from a pro audio manufacturer. It's the real deal but I'm all about verifying now with multiple sources. It's damn shame. You can't imagine how much time I've wasted.


Care to share your pink noise source?


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## Drop11 (Jul 4, 2016)

On a positive note. I now have tons of music I can listen to in my car now. Before I couldnt even think about putting in a rock cd without the thought of my ears hurting.
Now everything sounds awesome.


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## Drop11 (Jul 4, 2016)

ndm said:


> Drop11 said:
> 
> 
> > I will for verification. My pink noise file comes from a pro audio manufacturer. It's the real deal but I'm all about verifying now with multiple sources. It's damn shame. You can't imagine how much time I've wasted.
> ...


It was given to me from my cousin who is the lead audio engineer at the personus studio here in town.
It's only 30 seconds. They use it for bench testing new equipment. He's going to loop it for me to around 30 minutes at the studio so he can use an ultra high sampling rate.
I'd be more than happy to share the files.


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## Drop11 (Jul 4, 2016)

Another thought. As much as people share their REW graphs here wouldn't it make sense that there be a singular pink noise file available to the forum?
Seems like it could do some good.


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## Onyx1136 (Mar 15, 2009)

Most people don't realize there are multiple types of pink noise. I've also found several cd's that had white noise labeled as pink noise. Gotta know what you're dealing with before you start.


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## Drop11 (Jul 4, 2016)

Onyx1136 said:


> Most people don't realize there are multiple types of pink noise. I've also found several cd's that had white noise labeled as pink noise. Gotta know what you're dealing with before you start.


Truth. I know the differences between pink noise. I just didn't realize how far off they could be from source to source.


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## Justin Zazzi (May 28, 2012)

There is nothing magical about "professional" pink noise. In fact, most pink noise is not very useful because it is not periodic so you have to wait for a very long time in order to get a reasonable average over time.

Try this instead.

Download Room EQ Wizard. It's free. Open it up, click on the "Generator" button in the top toolbar. Choose "Pink PN" from the drop down menu, "full range" from the buttons underneath, set an RMS level of zero, and make a note of the sequence length (I think it's 65,536 by default. Click that WAV button and save the file anywhere on your computer.

Boom. Done. 60 seconds of proper pink noise for anyone to use. You could stop here, but it gets better.

In REW, open the RTA window and then click on the gear in the top-right corner to access some settings. Make sure Mode is set to one of the RTA options like 1/48 Octave. Smoothing should be greyed out when you're done here. FFT Length needs to match the sequence length of the periodic pink noise you generated earlier (if you forgot it's the first number of the file name). Averages should be none. Window needs to be rectangular. The last two options Overlap and Interval and your choice.

Play that periodic pink noise and turn on that RTA module. The graph will update *perfectly* every time without any need to average tons of samples over time. You can still use spatial averaging to average many samples over a 3D space near your head if you like though, just change the Averages from None to Infinite and do as much as you like.

If you have some spare time and want to know why this "periodic" thing is so cool, you can watch the video below to see how it works. It's not super technical and should be easy to understand, but it is a little on the long side.


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## haakono (Apr 5, 2009)

Jazzi, thanks for the REW tip for creating a PN file  

Just done it now, I have been using a mp3 file from a Bass Mekanik audio tool CD rip until now. will be interesting to compare them later on


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## Drop11 (Jul 4, 2016)

JazzI, I use REW. my issue came from a poor quality mp3 with p noise that was not correct in the first place. 180-300hz was up over 12 db, 1kz-5kHz was down almost 8 db and there were other signifigantly narrower peaks and dips though out the spectrum. I've since fed the old noise through an analyzer and it was all over the place response wise.


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## Onyx1136 (Mar 15, 2009)

Drop11 said:


> JazzI, I use REW. my issue came from a poor quality mp3 with p noise that was not correct in the first place. 180-300hz was up over 12 db, 1kz-5kHz was down almost 8 db and there were other signifigantly narrower peaks and dips though out the spectrum. I've since fed the old noise through an analyzer and it was all over the place response wise.


The fact that it was an MP3 could also have been the problem. MP3 encoding compresses and discards information at certain frequency spectrums to reduce the file size. With pink noise being full spectrum from 20-20 kHz, it's going to dump a lot of valuable output information that you're going to need in order to take a proper measurement. 

Pink noise (or any other measurement signals) should NEVER come from a compressed source such as MP3. Personally, I would even hesitate to use pink noise that had compressed to lossless FLAC. I'm not 100% sure that FLAC would make a measureable difference, but is there a good reason to chance it?


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## jackk (Dec 27, 2010)

So your mid bass issue was related to the pink noise you used for tuning?


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## Drop11 (Jul 4, 2016)

jackk said:


> So your mid bass issue was related to the pink noise you used for tuning?
> 
> 
> Sent from my iPhone using Tapatalk


Yes and no. The bass from the drivers is still slightly out if phase bit it's responsive to eq so I'm not sweating it anymore.


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## Lanson (Jan 9, 2007)

Sweeps are annoying (even with hearing protection) and slow (due to multiple sweeps to average) but so much better, IMO.

REW with sweeps is just awesome, so much useful info gathered and you're talking about things that matter, like a waterfall plot to understand resonance/excitement frequencies.


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## jackk (Dec 27, 2010)

Drop11 said:


> Yes and no. The bass from the drivers is still slightly out if phase bit it's responsive to eq so I'm not sweating it anymore.




Oh nice to know u r making progress. One day I may get to play w/ those focal drivers when budget allows 



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## Drop11 (Jul 4, 2016)

jackk said:


> Drop11 said:
> 
> 
> > Yes and no. The bass from the drivers is still slightly out if phase bit it's responsive to eq so I'm not sweating it anymore.
> ...


They are really nice. Especially the tweeters but honestly I feel like there is better out there for less money. 
I think a scan mid with a scan BE tweeter would be as good if not better for a fraction of the price.


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## caraudiopimps (May 4, 2016)

Drop11 said:


> Another thought. As much as people share their REW graphs here wouldn't it make sense that there be a singular pink noise file available to the forum?
> Seems like it could do some good.


I'm gonna go ahead and assume the link Arc audio provides for the ps8 is pretty clean, if not, I'll just run pink noise out of my DAW.


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## caraudiopimps (May 4, 2016)

Drop11 said:


> JazzI, I use REW. my issue came from a poor quality mp3 with p noise that was not correct in the first place. 180-300hz was up over 12 db, 1kz-5kHz was down almost 8 db and there were other signifigantly narrower peaks and dips though out the spectrum. I've since fed the old noise through an analyzer and it was all over the place response wise.


Any file you use to tune anything should be fully analyzed before use, spectrum analyzed at the least, but in the past, I have gone with programs which spit out sample rate etc too.


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## caraudiopimps (May 4, 2016)

Onyx1136 said:


> The fact that it was an MP3 could also have been the problem. MP3 encoding compresses and discards information at certain frequency spectrums to reduce the file size. With pink noise being full spectrum from 20-20 kHz, it's going to dump a lot of valuable output information that you're going to need in order to take a proper measurement.
> 
> Pink noise (or any other measurement signals) should NEVER come from a compressed source such as MP3. Personally, I would even hesitate to use pink noise that had compressed to lossless FLAC. I'm not 100% sure that FLAC would make a measureable difference, but is there a good reason to chance it?


Wav is fine too.


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## Onyx1136 (Mar 15, 2009)

caraudiopimps said:


> Wav is fine too.


Of course. And course that is uncompressed is fine. CD, DVD, wav, tone generator apps, noise from software like REW, etc are all fine. The most critical criteria is that it is an uncompressed source.


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## Drop11 (Jul 4, 2016)

It goes a little deeper than that. The algorithm had to be spot on. There's a tutorial on YouTube by a forum member on how to tune an sq car. He had a nice little rant about pink noise on there. I didn't catch his source but I thought it was being generated by REW and he wasn't happy with it. Thus is what initially got me to check it in the first place and sure enough it was off. Way off. Then I started researching. 
Most of us will touch up by ear anyway but I know how anal we as a group can be too.


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## mirkinator (Feb 22, 2016)

Drop11 said:


> It goes a little deeper than that. The algorithm had to be spot on. There's a tutorial on YouTube by a forum member on how to tune an sq car. He had a nice little rant about pink noise on there. I didn't catch his source but I thought it was being generated by REW and he wasn't happy with it. Thus is what initially got me to check it in the first place and sure enough it was off. Way off. Then I started researching.
> Most of us will touch up by ear anyway but I know how anal we as a group can be too.




His YouTube (real?) name is Kyle Ragsdale.

Here is a link to the video. He responded in the comments and said REW generated pink noise is fine. 

https://youtu.be/KX7ibDXiqnc


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## Extended Power (Jun 8, 2014)

Jazzi said:


> There is nothing magical about "professional" pink noise. In fact, most pink noise is not very useful because it is not periodic so you have to wait for a very long time in order to get a reasonable average over time.
> 
> Try this instead.
> 
> ...


New version was available, so I downloaded, and overwrote my older version of it.
The new version only goes to -3.0 dBFS.....do you think it will be an issue?


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## Weigel21 (Sep 8, 2014)

LOL, I've always known compressed audio cuts certain frequencies upon compression, but for the life of me, it completely skipped my mind when I went n downloaded pink noise in MP3 format to measure my system's response. Not only was I using an iffy measurement tool, but now I realize I was using a compressed pink noise track. Duh, No wonder I can't get my system to sound decent (enough) to myself. 

Man, I so miss my younger "ignorant" days when I just cranked up my music and loved the way it sounded.


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## Pariah Zero (Mar 23, 2016)

Onyx1136 said:


> I'm not 100% sure that FLAC would make a measureable difference


FLAC does not change the signal in any way. 

FLAC (and other lossless formats like Apple Lossless, Monkey's Audio, etc.) are a lot like "zip" files on a computer.

Just like a zip file, when a FLAC file is uncompressed, the output is bit-for-bit identical to the original. It's a perfect copy. Zero loss, zero change.

FLAC is a superior format to WAV in every possible way. 

The only thing WAV has going for it is that it's much older, so more head units can play them.



Onyx1136 said:


> is there a good reason to chance it?


Several. FLAC is more robust, and has internal data protections WAV lacks. For example: disk drives slowly degrade over time, corrupting data. Flash drives (especially USB thumb drives) are especially unreliable. 

A WAV file has no mechanism to detect (or correct) corruption. FLAC does.

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## Drop11 (Jul 4, 2016)

Weigel21 said:


> LOL, I've always known compressed audio cuts certain frequencies upon compression, but for the life of me, it completely skipped my mind when I went n downloaded pink noise in MP3 format to measure my system's response. Not only was I using an iffy measurement tool, but now I realize I was using a compressed pink noise track. Duh, No wonder I can't get my system to sound decent (enough) to myself.
> 
> Man, I so miss my younger "ignorant" days when I just cranked up my music and loved the way it sounded.


Fantastic. Nice to know I'm not alone. Tuning really isn't that hard but we screwed ourselves from the start lol.
And yes, those were the days! I was happy as long as I could feel it!


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## Justin Zazzi (May 28, 2012)

Extended Power said:


> New version was available, so I downloaded, and overwrote my older version of it.
> The new version only goes to -3.0 dBFS.....do you think it will be an issue?


For tuning with an RTA? Nope.


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## jackk (Dec 27, 2010)

Drop11 said:


> They are really nice. Especially the tweeters but honestly I feel like there is better out there for less money.
> I think a scan mid with a scan BE tweeter would be as good if not better for a fraction of the price.




Thx for the thought, will definitely look at scan if I change my setup!


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## Onyx1136 (Mar 15, 2009)

Pariah Zero said:


> FLAC does not change the signal in any way.
> 
> FLAC (and other lossless formats like Apple Lossless, Monkey's Audio, etc.) are a lot like "zip" files on a computer.
> 
> ...


Interesting. I've never heard FLAC files explained that way. Then again, I've not done that much research into FLAC files. Really good information. I've always understood FLAC to just be a better form of compression. 

My point was not to say that Wav is a better file type than FLAC, but that it was uncompressed, which makes it suitable for use in tuning. Now that I know more about FLAC, obviously it too is perfectly suitable for use in tuning as well. Thanx for the heads up, Pariah.


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## Pariah Zero (Mar 23, 2016)

Onyx1136 said:


> Interesting. I've never heard FLAC files explained that way. Then again, I've not done that much research into FLAC files. Really good information. I've always understood FLAC to just be a better form of compression.
> 
> 
> 
> My point was not to say that Wav is a better file type than FLAC, but that it was uncompressed, which makes it suitable for use in tuning. Now that I know more about FLAC, obviously it too is perfectly suitable for use in tuning as well. Thanx for the heads up, Pariah.



The sad fact is there are many things called "compression" in audio, and the same word has _totally_ different meanings - and some have nothing to do with file size.


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## Onyx1136 (Mar 15, 2009)

Pariah Zero said:


> The sad fact is there are many things called "compression" in audio, and the same word has _totally_ different meanings - and some have nothing to do with file size.
> 
> 
> Sent from my iPhone using Tapatalk


Perhaps a new term needs to be coined for the algorithms that reduce file size, but do not actually alter the original information through the "traditional" method of discarding information in certain bandwidths?


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## Justin Zazzi (May 28, 2012)

I think the term you're looking for is "lossless" compression?
Flac, Alac, Ogg, Zip, Rar, and other formats are like this.


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## Pariah Zero (Mar 23, 2016)

Jazzi said:


> I think the term you're looking for is "lossless" compression?
> Flac, Alac, Ogg, Zip, Rar, and other formats are like this.



Careful with ogg!

Ogg is a "container" format, and can hold many kinds of media.

FLAC is one, and is lossless. However, ogg can also hold Vorbis, opus, and theora media as well - all of which are lossy.

Though Opus is just amazing. It's probably the best lossy compression at the moment, easily outclassing AAC.



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## Justin Zazzi (May 28, 2012)

Hmm ... learn something new every day!
Thanks for pointing that out. I must have misread something long ago.


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## Pariah Zero (Mar 23, 2016)

For compression types (not an exhaustive list)

• Dynamic compression. This doesn't really make files smaller.

It's used to fit the recording to the medium. For example, 0 dBFS for digital audio, or the physical limitations of analog media (record grooves or magnetic strength). Because drum hits, gunfire, explosions, etc. can all be louder than the medium can handle. So it compresses the dynamic range so you don't have distortion. 

Dynamic compression is also famously abused in the loudness war

• lossless compression: this perfectly preserves the original signal. It's kind of like squeezing a sponge flat. The sponge isn't damaged or destroyed, and can grow back to its original size.

• lossy compression: cuts out most of the original signal. This is like cutting up a sponge, throwing away most of it, and then squeezing what's left. It works because there are serious limitations to both our ears and brains.

Lossy compression has evolved a lot in 40 years. The techniques have gotten much better at throwing out what we can't hear, and keep what we can.

Lossy codecs vary wildly in quality and bitrate. More bits isn't better. What's important is how well it cuts stuff we don't hear. (While preserving what we do)

Old codecs (like AptX) are pretty bad at their job: they cut out the 'wrong' bits, and need a much higher bitrate to sound good.

Newer codecs like AAC and Opus do a much better job, and can be indistinguishable from the original in ABX testing — even though 80-90% of the signal is thrown away. They are both smaller and sound better than lower quality codecs.

But for all the awesome of new lossy codecs, they are designed for the limitations of our ears — not the limitations of a measurement mic and an RTA.


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## caraudiopimps (May 4, 2016)

Pariah Zero said:


> FLAC does not change the signal in any way.
> 
> FLAC (and other lossless formats like Apple Lossless, Monkey's Audio, etc.) are a lot like "zip" files on a computer.
> 
> ...


Agreed, however, as a format, from a known source, I'd say wav is okay. I use flac, but would have no problem ripping pink noise to wav if need be. I tend to use best plugins in a DAW to generate a 30sec burst of pink noise, run it through a spectrum analyzer, and record it to lossless format at whatever gain I need it at (-3db etc.).


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## caraudiopimps (May 4, 2016)

Pariah Zero said:


> Careful with ogg!
> 
> Ogg is a "container" format, and can hold many kinds of media.
> 
> ...


Someone is a what.cd member!


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## Pariah Zero (Mar 23, 2016)

caraudiopimps said:


> Someone is a what.cd member!



Um... No idea what that is.

I'm just an electrical engineer who studied analog and digital signals & processing for several years.

I have a significant interest in digital recording (both audio and video) 

Back in my university days, I was seriously considering designing an Ogg Vorbis (lossy codec) decoder chip. It's a long story, but entertainment tech doesn't get grant money easily.

I'll never know more than a fraction of what Andy W. knows about audio. I definitely need a few decades to be as diplomatic as he seems to be.


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## Pariah Zero (Mar 23, 2016)

caraudiopimps said:


> Agreed, however, as a format, from a known source, I'd say wav is okay.



WAV is okay.

It's just that FLAC is better. Which shouldn't be a surprise, as it's a decade more advanced.


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## caraudiopimps (May 4, 2016)

Pariah Zero said:


> WAV is okay.
> 
> It's just that FLAC is better. Which shouldn't be a surprise, as it's a decade more advanced.
> 
> ...


No doubt, and what.cd is a torrent site with extensive format questions during the interview process, yeah, they actually interview new applicants. Actually one of the better sources for lossless content, but the reason I said that is due the your comment being almost exactly one of the answers to one of the interview questions. If you ever wanted to join that torrent group, you'd have no issues.


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## Weigel21 (Sep 8, 2014)

I wanted to join What.CD a few years back when I found out about it, but there was no way I was going to be able to pass an "interview" and I didn't personally know anyonw with a spare invite.


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## caraudiopimps (May 4, 2016)

Weigel21 said:


> I wanted to join What.CD a few years back when I found out about it, but there was no way I was going to be able to pass an "interview" and I didn't personally know anyonw with a spare invite.


I interviewed one time, my internet happened to disconnect about halfway through the interview, wasting the 5+hrs I sat waiting on the chat for an interview. After that, I gave up.


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## lizardking (Nov 8, 2008)

Is FLAC a better option for tuning versus the old WAV format?


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## Justin Zazzi (May 28, 2012)

Better? Not really. They will both give you the same result.

FLAC might be more robust in the long term though, as Pariah Zero points out in post #28 above.


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