Equalizer using white noise

Paul Irving

New Member
So I'm considering setting up my old stereo system and have a question.

Back in the day (mid 80's) I bought a system in bits and pieces. Now I find that some of it is quite rare.

One thing I do remember is that I used to set it up using a spectrum analyzer and white noise generator. The idea was to place a mic at the listening position, turn on the white noise and balance the sound to exactly flat. I was told this would be as close to hearing the sound as it was recorded. Is this true? Is it still a thing? I used my ADC SS-315X which had the mic and white noise generator.

I will say the music sounded incredibly good to me this way.

BTW I found this forum by looking for information on my Sansui B1 amp, which I have found out is very rare. Who knew?
 
It's definitely a thing. Precursor to the "room correction" used in many modern AVRs although the latter now also check phase and delay as well. But the white noise will get you in the ballpark, as frequency response is the most noticeable "error" in sound reproduction.

I have the same EQ by the way but sadly have never used it as you describe as it came to me without the mic.
 
My father does spectral analysis of his livingroom using white noise. I don't do it with my listening space, but I probably should. I know that my father doesn't aim for perfectly flat response.
 
So I'm considering setting up my old stereo system and have a question.

Back in the day (mid 80's) I bought a system in bits and pieces. Now I find that some of it is quite rare.

One thing I do remember is that I used to set it up using a spectrum analyzer and white noise generator. The idea was to place a mic at the listening position, turn on the white noise and balance the sound to exactly flat. I was told this would be as close to hearing the sound as it was recorded. Is this true? Is it still a thing? I used my ADC SS-315X which had the mic and white noise generator.

I will say the music sounded incredibly good to me this way.

BTW I found this forum by looking for information on my Sansui B1 amp, which I have found out is very rare. Who knew?


Welcome to AK!

Yes, that is the correct approach. You would have a baseline from which you can adjust to taste from. Without a bassline, no one knows what you are hearing :) (Also use speaker and listening position movments to adjust, don't do it in the EQ only. Always remember: Boost to make it sound different, cut to make it sound better, and you can put 200 watts into a null mode, but it will not change anything - so don't try to boost nulls :))


I do it with a USB measurment mic and the open source software Room EQ Wizard from Home Theater Shack = https://www.minidsp.com/applications/acoustic-measurements/umik-1-setup-with-rew

https://www.minidsp.com/
 
I may be misinformed, but since 1978 I've always used Pink noise. All the literature I remember reading has always said use Pink noise.
 
You guys are right, of course. White noise is equal energy per frequency and pink noise is equal energy per octave.
 
Yep, I used the pink noise generator of my AudioSource EQ and condenser mike to make adjustments to certain frequencies. I have tile floors under my speakers and laminate in the middle of the room so our 26' x 18' livingroom is a challenge for a good setup so it was a big help
 
Yep, I used the pink noise generator of my AudioSource EQ and condenser mike to make adjustments to certain frequencies. I have tile floors under my speakers and laminate in the middle of the room so our 26' x 18' livingroom is a challenge for a good setup so it was a big help

Well the problem there would be that the EQ only generates white noise. I do remember getting some pretty incredible sound regardless. I used my big amp for the bass only and have something called a phase coupled activator...I can't remember exactly what it does but I know it helped me flatten the low bass. There was a time when I had this thing running for hours every day. Then my second wife happened and she hated it. I had really just forgotten/ignored it for years until 3rd wife and I decided to listen to some old Eagles. We then decided it would sound so good on a decent system.

My stuff is all pretty ancient now, but it was pretty good back in the day. It was back when the discussion was all about CD verses records. I even had a big old reel to reel, but I got rid of that. I still have the Ariston turntable too.
 
[QUOTE="Paul Irving, post: 11053044, member: 273351"...something called a phase coupled activator...I can't remember exactly what it does but I know it helped me flatten the low bass.[/QUOTE]

It's made by audiocontrol. It's like a really cool loudness function, but they describe it as a tool to restore the bass that was not captured (or filtered out) in the recording process, it "senses" existing bass frequencies and reproduces them an octave lower.

I think of it more as synthetic bass because what it creates may not have been there in the first place. Not pure, but lots of fun.
 
[QUOTE="Paul Irving, post: 11053044, member: 273351"...something called a phase coupled activator...I can't remember exactly what it does but I know it helped me flatten the low bass.

It's made by audiocontrol. It's like a really cool loudness function, but they describe it as a tool to restore the bass that was not captured (or filtered out) in the recording process, it "senses" existing bass frequencies and reproduces them an octave lower.

I think of it more as synthetic bass because what it creates may not have been there in the first place. Not pure, but lots of fun.[/QUOTE]

Used that during my "dj" days in many clubs to "extend" the bass.
 
Years ago we used pink noise generators and spectrum analysers to set up PA systems. It was a good indicator of what we called 'house effect'. This is where you already know how your system should be set, but this allowed fine tuning to correct for room acoustics. Generally we would set the system to be bass light initially because once the venue was full of treble absorbers (also known as people) the sound balance would level out.
These days, sound setup is done with computer backed tone burst systems which not only measure and correct for tonal balance, but also carryout speaker distance offset adjustments and take account of room reflections as well.
At the end of the day, as with hifi, the final judgement still uses the best tools in the box - EARS!
 
Well the problem there would be that the EQ only generates white noise. I do remember getting some pretty incredible sound regardless. I used my big amp for the bass only and have something called a phase coupled activator...I can't remember exactly what it does but I know it helped me flatten the low bass. There was a time when I had this thing running for hours every day. Then my second wife happened and she hated it. I had really just forgotten/ignored it for years until 3rd wife and I decided to listen to some old Eagles. We then decided it would sound so good on a decent system.

My stuff is all pretty ancient now, but it was pretty good back in the day. It was back when the discussion was all about CD verses records. I even had a big old reel to reel, but I got rid of that. I still have the Ariston turntable too.
Dig your adc ss-315x out and take a look. It's the same as the bsr eq-3000.
They have a "pink noise" generator.:thumbsup:
 
Well the problem there would be that the EQ only generates white noise. I do remember getting some pretty incredible sound regardless. I used my big amp for the bass only and have something called a phase coupled activator...I can't remember exactly what it does but I know it helped me flatten the low bass. There was a time when I had this thing running for hours every day. Then my second wife happened and she hated it. I had really just forgotten/ignored it for years until 3rd wife and I decided to listen to some old Eagles. We then decided it would sound so good on a decent system.

My stuff is all pretty ancient now, but it was pretty good back in the day. It was back when the discussion was all about CD verses records. I even had a big old reel to reel, but I got rid of that. I still have the Ariston turntable too.

Your ADC Sound Shaper SS-315X has a Pink Noise generator. You can get a copy of the manual at hifiengine.com .
 
It's made by audiocontrol. It's like a really cool loudness function, but they describe it as a tool to restore the bass that was not captured (or filtered out) in the recording process, it "senses" existing bass frequencies and reproduces them an octave lower.

I think of it more as synthetic bass because what it creates may not have been there in the first place. Not pure, but lots of fun.

Used that during my "dj" days in many clubs to "extend" the bass.

Sounds like a dbx 120 Subharmonic Synthesizer to me.
 
When I use an Equalizer at all, usually it is to adjust for pre-RIAA recordings pre-standardization. I use the frequency balance of the lead in surface noise to make the adjustments. This idea has a valid approach. Get the midrange right, and the rest pleasant to one's ear, you're good.
 
When I use an Equalizer at all, usually it is to adjust for pre-RIAA recordings pre-standardization. I use the frequency balance of the lead in surface noise to make the adjustments. This idea has a valid approach. Get the midrange right, and the rest pleasant to one's ear, you're good.

When you do this what do you use as a phono preamp?
 
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