Hello,
I've been reading this and other forums for a while in the interest of getting my studio rooms into shape.
I've installed ETF acoustical analysis software and purchased a Behringer test mic. I began testing my control room today and I found that my readings were all over the place. I mean that one test would show that I had a dip of 25 dB @ 100Hz, but then 5 seconds later I would run the test again and it would say that I only have an 8 dB dip @ 100Hz. I don't understand it.
Basically, the thing is going wild. I'm very confident that it is hooked up right. Usually, there is a general theme that applies to each analysis. The biggest dips remain the biggest dips, but then sometimes they are 10db and sometimes they are 20db.
Is there any reason for this? Nothing in the room is changing. I'm using my computer which I mix on to perform the tests and I try to get out of the way of the mic as quickly as possible.
I have the mic positioned where my head would be when I mix. I tried running each speaker individually and both simultaneously. No matter what I did, the results seamed to be inconsistent, even when everything else stayed consistent.
Any ideas?
Brandon
Inconsistent room testing
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brandondrury
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Aaronw
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Andrew Steel
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Brandon,
Don't forget that these measurements are reported statistically usually. A lab takes many measurements and reports the average and standard deviation.
Other problems may be that you are getting distortion in the MLS causing spurious spikes. Make sure you are not driving the speaker any louder than necessary.
Andrew
Don't forget that these measurements are reported statistically usually. A lab takes many measurements and reports the average and standard deviation.
Other problems may be that you are getting distortion in the MLS causing spurious spikes. Make sure you are not driving the speaker any louder than necessary.
Andrew
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brandondrury
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I tried running pink noise, sweeps, etc. It really didn't matter what I ran, I would never seam to get the same results twice. The only variable that could possibly make a difference would be my own body. I click "go" and then try to get out of the way of the speakers. Ideally, I would be out of harms way, but by the way my system is setup, I really can't do that. I guess I could get an extender for my keyboard and mouse. However, it really seams odd that room would swing 30dB just because my head moved 8 inches.
The construction of my room is....odd. The room is 15x20x9, but has a fireplace (it used to be a living room). The fireplace is centered on 20 foot wall and extends several feet into the room. My monitors are centered on the opposite wall to the fireplace. I've not done any treatment to the room yet. The floors are what seam to be relatively thin hardwood floors which I have put a layer of parquette with polyurethane.
The house is quite old and it was obviously added on to at one point. This room was extended what looks like to be 10 feet.
The walls are standard drywall. The ceiling is a drop ceiling.
I'm trying to give you as much information as possible that I can recall from memory. I'm not at the studio now.
I hope this helps you help me.
Brandon Drury
The construction of my room is....odd. The room is 15x20x9, but has a fireplace (it used to be a living room). The fireplace is centered on 20 foot wall and extends several feet into the room. My monitors are centered on the opposite wall to the fireplace. I've not done any treatment to the room yet. The floors are what seam to be relatively thin hardwood floors which I have put a layer of parquette with polyurethane.
The house is quite old and it was obviously added on to at one point. This room was extended what looks like to be 10 feet.
The walls are standard drywall. The ceiling is a drop ceiling.
I'm trying to give you as much information as possible that I can recall from memory. I'm not at the studio now.
I hope this helps you help me.
Brandon Drury
Last edited by brandondrury on Sat Aug 07, 2004 1:09 am, edited 1 time in total.
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Aaronw
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Is the fireplace flue open or closed? Is your room rectangular or do you have angles/symmetrical?
Do you have anything near by that causes a small "rumble", eg: train tracks, airplanes, highways, etc.
What happens if you sit in the pilot seat at the console? That's where you'll be anyway. See what results you get there.
Andrew is right about the differences. They will change. Do you have an HVAC unit running when you've tested? Temperature in the room will also have an affect on what happens. Sound travels faster or slower depending on temperature, humidity, altitude.
Do you have anything near by that causes a small "rumble", eg: train tracks, airplanes, highways, etc.
What happens if you sit in the pilot seat at the console? That's where you'll be anyway. See what results you get there.
Andrew is right about the differences. They will change. Do you have an HVAC unit running when you've tested? Temperature in the room will also have an affect on what happens. Sound travels faster or slower depending on temperature, humidity, altitude.
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brandondrury
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The fireplace is closed and has a couch in front of it anyway. The room is rectangular. However, as I stated before the fireplace does jet out approx 2 foot into the room.
There's always the chance of something adding rumble, but it's just barely audible when it does. There are no trains shaking the house.
It's possible that I may have made a footstep when trying to get out of the way. I'll just put the test mic above my head and sit in the mix position.
Brandon
There's always the chance of something adding rumble, but it's just barely audible when it does. There are no trains shaking the house.
It's possible that I may have made a footstep when trying to get out of the way. I'll just put the test mic above my head and sit in the mix position.
Brandon
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wmb
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I will suggest something that might seem insulting but I mean no offence.
I don't know how you are testing but if it involves recording you need to make sure the previously recorded tests are muted during the testing. The way I have been testing my room is with the Sonar file from the realtraps site. Sine waves from 40 to 300 hz for one second each. I made the error above once but figured it out rather quickly. Just a thought.
You might want to try that test if you can with the Sonar demo. Pretty dramatic.
Good luck.
I don't know how you are testing but if it involves recording you need to make sure the previously recorded tests are muted during the testing. The way I have been testing my room is with the Sonar file from the realtraps site. Sine waves from 40 to 300 hz for one second each. I made the error above once but figured it out rather quickly. Just a thought.
You might want to try that test if you can with the Sonar demo. Pretty dramatic.
Good luck.
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brandondrury
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lex125
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Basically, the thing is going wild..... The biggest dips remain the biggest dips, but then sometimes they are 10db and sometimes they are 20db.
Is there any reason for this? Nothing in the room is changing.
Glad to know that I'm not the only one with these kinds of results. My swings were not anywhere near that big, more like -6dB one time and -9dB the next. I was more surprised to see the drastic changes between adjacent frequencies: in a span of 4 frequencies I might get results like +5, +5, -9, +6. And this was typical throughout the 40Hz to 15kHz range that I tested. I was expecting gentle rolling curves when I plotted the points, instead I got a bunch of nearly vertical lines connecting many of the points.
I guess that this type of sharp frequency problems shouldn't be unexpected in an extremely small room (14ftx8ft). I can also confirm that your body can easily cause 6dB spikes in your results. I made my measurements using a handheld dB meter and a test tone CD. I had the meter mounted on a mic stand and postioned at my listening position. I then moved as far away as I could so that I could still read the meter display (about 6ft). As a test, I would set things so that a frequency would play continuously. I then walked from my location 6ft from the meter very slowly towards the meter. I noticed +/-6dB swings to the readout just based on my change in location, often by less than 1/2 ft.
Is there any reason for this? Nothing in the room is changing.
Glad to know that I'm not the only one with these kinds of results. My swings were not anywhere near that big, more like -6dB one time and -9dB the next. I was more surprised to see the drastic changes between adjacent frequencies: in a span of 4 frequencies I might get results like +5, +5, -9, +6. And this was typical throughout the 40Hz to 15kHz range that I tested. I was expecting gentle rolling curves when I plotted the points, instead I got a bunch of nearly vertical lines connecting many of the points.
I guess that this type of sharp frequency problems shouldn't be unexpected in an extremely small room (14ftx8ft). I can also confirm that your body can easily cause 6dB spikes in your results. I made my measurements using a handheld dB meter and a test tone CD. I had the meter mounted on a mic stand and postioned at my listening position. I then moved as far away as I could so that I could still read the meter display (about 6ft). As a test, I would set things so that a frequency would play continuously. I then walked from my location 6ft from the meter very slowly towards the meter. I noticed +/-6dB swings to the readout just based on my change in location, often by less than 1/2 ft.
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brandondrury
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Well, I feel better. Either we are experiencing similar problems or we are both idiots. I'm using test software and a Behringer test mic, but my tests end with similar results.
If moving a person can make up to 6dB difference, then how can you possibly mix in this way. Sometimes I mix bymyself. Sometimes I mix with 3 or 4 guys in the couch behind me. Personally, I don't hear a difference. Then again, I don't think I have special ears. I certainly don't care about the difference between my 1272 preamps and my Mackie preamps (except for noise).
I traded a local band some recording time and I had them sew up about 40 2'x4' Rockwool panels to avoid all the itchy fibers on the walls. Anyway, these are piled up in one side of the room and I can't really hear a difference in my mixes. I'm beginning to wonder just how important this whole accurate room thing really is.
I certainly do see the merit in an accurate room, I'm just not sure if it's obtainable or will even be noticeable in my mixes. Thus far, the best way I've scene to improve the quality of my mixes is the source instrument. Better drums with better tuning, better guitar amps, and better singers seam to sound way better than acoustic treatment.
Then again, I'm in the budget world. I have to compromise. If I didn't, maybe I would hear a greater difference. Hell, the other day I heard Mariah Carey on a PA system and I could hear a sparkle in her voice that I've never achieved on my recordings. Granted, I have no desire to sound like Mariah Carey, but none the less, it seamed in this case that the speaker system and acoustics had little to do with hearing this extra sparkle.
It sounds like the issue is with the source, my mics, and me.
Brandon
If moving a person can make up to 6dB difference, then how can you possibly mix in this way. Sometimes I mix bymyself. Sometimes I mix with 3 or 4 guys in the couch behind me. Personally, I don't hear a difference. Then again, I don't think I have special ears. I certainly don't care about the difference between my 1272 preamps and my Mackie preamps (except for noise).
I traded a local band some recording time and I had them sew up about 40 2'x4' Rockwool panels to avoid all the itchy fibers on the walls. Anyway, these are piled up in one side of the room and I can't really hear a difference in my mixes. I'm beginning to wonder just how important this whole accurate room thing really is.
I certainly do see the merit in an accurate room, I'm just not sure if it's obtainable or will even be noticeable in my mixes. Thus far, the best way I've scene to improve the quality of my mixes is the source instrument. Better drums with better tuning, better guitar amps, and better singers seam to sound way better than acoustic treatment.
Then again, I'm in the budget world. I have to compromise. If I didn't, maybe I would hear a greater difference. Hell, the other day I heard Mariah Carey on a PA system and I could hear a sparkle in her voice that I've never achieved on my recordings. Granted, I have no desire to sound like Mariah Carey, but none the less, it seamed in this case that the speaker system and acoustics had little to do with hearing this extra sparkle.
It sounds like the issue is with the source, my mics, and me.
Brandon
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lex125
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Well, I feel better. Either we are experiencing similar problems possibly
or we are both idiots. probably.....
If moving a person can make up to 6dB difference, then how can you possibly mix in this way. Sometimes I mix by myself. Sometimes I mix with 3 or 4 guys in the couch behind me. Personally, I don't hear a difference.
Rockwool panels ..........are piled up in one side of the room and I can't really hear a difference in my mixes. I'm beginning to wonder just how important this whole accurate room thing really is.
Where you'll notice the difference is when you get a chance to work in a great room. You'll listen to a CD you are familiar with and it will sound like a whole new recording. If you are frustrated with your room now, wait until you've heard a GREAT room. Then you'll really be bummed.
I certainly do see the merit in an accurate room, I'm just not sure if it's obtainable or will even be noticeable in my mixes. Thus far, the best way I've scene to improve the quality of my mixes is the source instrument. Better drums with better tuning, better guitar amps, and better singers seam to sound way better than acoustic treatment.
Ding Ding Ding! YES! A great band playing a great song is #1. Great signal chain (with Mics the most important) is #2. For some of us, that's all we can hope for. That's why smart engineers leave mastering for the pro's.
Just because the last issue of Computer Music included a "mastering plug-in" is no reason to think that this important step is no longer needed. The real mastering guys have that absurdly expensive gear and that room with perfect acoustics. My job is to capture the best sounds possible. Fortunately, in my end of the biz (remote recording of acoustic music), the "mix" phase is a very minor step. I record the best sounds I can and then ship things to Mr. Big Ears.
Until I can afford all custom built equipment and a million dollar room, this seems like the right way to work, for me.
or we are both idiots. probably.....
If moving a person can make up to 6dB difference, then how can you possibly mix in this way. Sometimes I mix by myself. Sometimes I mix with 3 or 4 guys in the couch behind me. Personally, I don't hear a difference.
Rockwool panels ..........are piled up in one side of the room and I can't really hear a difference in my mixes. I'm beginning to wonder just how important this whole accurate room thing really is.
Where you'll notice the difference is when you get a chance to work in a great room. You'll listen to a CD you are familiar with and it will sound like a whole new recording. If you are frustrated with your room now, wait until you've heard a GREAT room. Then you'll really be bummed.
I certainly do see the merit in an accurate room, I'm just not sure if it's obtainable or will even be noticeable in my mixes. Thus far, the best way I've scene to improve the quality of my mixes is the source instrument. Better drums with better tuning, better guitar amps, and better singers seam to sound way better than acoustic treatment.
Ding Ding Ding! YES! A great band playing a great song is #1. Great signal chain (with Mics the most important) is #2. For some of us, that's all we can hope for. That's why smart engineers leave mastering for the pro's.
Just because the last issue of Computer Music included a "mastering plug-in" is no reason to think that this important step is no longer needed. The real mastering guys have that absurdly expensive gear and that room with perfect acoustics. My job is to capture the best sounds possible. Fortunately, in my end of the biz (remote recording of acoustic music), the "mix" phase is a very minor step. I record the best sounds I can and then ship things to Mr. Big Ears.
Until I can afford all custom built equipment and a million dollar room, this seems like the right way to work, for me.
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brandondrury
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As far as hearing mixes in a great room, I've certainly not done that.
However, I'm in the process of switching control rooms. When I first setup my monitors and hit play, I was blown away by how my more spatious the mixes sounded. Mixes down in my previous room were so much more intense now.
I really don't think I have a great room, but I can see your point about the great room really making it sound huge.
The only bum side is I really haven't noticed an impact on my new mixes. Just because the speakers sound more alive doesn't mean my mixes do. It seams as if I'm a bigger problem than my control room.
Brandon
However, I'm in the process of switching control rooms. When I first setup my monitors and hit play, I was blown away by how my more spatious the mixes sounded. Mixes down in my previous room were so much more intense now.
I really don't think I have a great room, but I can see your point about the great room really making it sound huge.
The only bum side is I really haven't noticed an impact on my new mixes. Just because the speakers sound more alive doesn't mean my mixes do. It seams as if I'm a bigger problem than my control room.
Brandon