mshilarious
Banned
COOLCAT said:
Very low . . . given the tolerance of the mic at +-1 to 2 dB across the range, it would take a real bad soundcard to make a difference.
Very low . . . given the tolerance of the mic at +-1 to 2 dB across the range, it would take a real bad soundcard to make a difference.
CoolCat
Well-known member
not to get crazy, but is this cheap of a mic "really" 20-20K at +/- 2db??
i have a SM7 that has a Flat setting and it isn't that flat?? its like 6db around 9-12K, and <5db the rest. 50-14K. also a MXL 603(can't fin the response curve of it?)
i've really been thinking of this and your test.
maybe its the fact your actually doing it live and not selling anything that builds the credibility. great stuff..
anyway, awaiting your After.... read.
but from your charts your pre's aren't bad and you adjusted the sub to tweak it in. What if you just played with your monitor placement could you smooth it out even more?
edit: RTA at Allen Heath .com free 14day trial..and <$10 if i buy. It let me burn a CDR to transfer to the old pc...
then plug in the mics i may have to and buy a "flat Behringer" next.
it uses the Eq calibrate to calibrate the microphone?? it says "use STUDIO MONITORS THAT ARE FLAT TO CALIBRATE YOUR MICROPHONE!!"
i have a SM7 that has a Flat setting and it isn't that flat?? its like 6db around 9-12K, and <5db the rest. 50-14K. also a MXL 603(can't fin the response curve of it?)
i've really been thinking of this and your test.
maybe its the fact your actually doing it live and not selling anything that builds the credibility. great stuff..
anyway, awaiting your After.... read.
but from your charts your pre's aren't bad and you adjusted the sub to tweak it in. What if you just played with your monitor placement could you smooth it out even more?
edit: RTA at Allen Heath .com free 14day trial..and <$10 if i buy. It let me burn a CDR to transfer to the old pc...
then plug in the mics i may have to and buy a "flat Behringer" next.
it uses the Eq calibrate to calibrate the microphone?? it says "use STUDIO MONITORS THAT ARE FLAT TO CALIBRATE YOUR MICROPHONE!!"
Last edited:
mshilarious
Banned
COOLCAT said:
The SM7 was not designed to be flat. The cheap measurement mics use really small diaphragms that are designed to be flat, and their small size makes them inexpensive. Musically, they sound like crap, and they are noisy to boot. But 22 dB self-noise makes no difference when you are testing signals at 85 dB.
Possibly, but that would be dependent on the room modes, which would change with treatment. If I can fix the sub's response, that eliminates another variable.
In my case I had simply made an error in my crossover design, and I would have had to have gotten really lucky to get an exactly offsetting room mode. It was easier to spend a couple of minutes with the soldering iron.
If you buy a commercial sub you should not have that problem. The perils of DIY
it uses the Eq calibrate to calibrate the microphone?? it says "use STUDIO MONITORS THAT ARE FLAT TO CALIBRATE YOUR MICROPHONE!!"
Yeah, that's a chicken and egg problem. A measurement mic will (in theory) have been calibrated with flat monitors in an anechoic chamber by the manufacturer--and props to Apex for including the mic's chart. Thus it's the ruler for the rest of your gear.
Looking like next week for the after test
CoolCat
Well-known member
update: no frkn $30 mics at GC. only one they had was DBX for $100.
no can do... right now for this.
if anyone has the time, is the Allen Heath RTA software any good, it doesn't look quite as detailed as mshilarious post.
http://www.allen-heath.com/DisplayProduct.asp?pview=32
i may play around with my MXL 991 (603) mic. its hyped i think for guitar range.
i was thinking about extrapolating the data too...
if the mic has 3db bump at 2K, then if the RTA says i have 5 db at 2K, subtract the 3db bump...and via extrapolation it would be a RTA 2db bump.
so we could actually use any mic by extrapolating the response curve vs the RTA curve.
theoretically.
i think thats basically what they did to decide on Pink Noise as the standard.... back to reading.
RTA unit ready to go except for the mic!
no can do... right now for this.
if anyone has the time, is the Allen Heath RTA software any good, it doesn't look quite as detailed as mshilarious post.
http://www.allen-heath.com/DisplayProduct.asp?pview=32
i may play around with my MXL 991 (603) mic. its hyped i think for guitar range.
i was thinking about extrapolating the data too...
if the mic has 3db bump at 2K, then if the RTA says i have 5 db at 2K, subtract the 3db bump...and via extrapolation it would be a RTA 2db bump.
so we could actually use any mic by extrapolating the response curve vs the RTA curve.
theoretically.
i think thats basically what they did to decide on Pink Noise as the standard.... back to reading.
RTA unit ready to go except for the mic!
Last edited:
CoolCat
Well-known member
apl said:
yeah, i read this again..its just amazing stuff. the articles of Ethan are imo, so well written that i don't fall asleep but get refreshed.
seems there's always one more piece to the puzzle each time i read those articles.
and alot of DIY stuff for the HR hobbyist.
ah, off to GC #2 & #3 ....to find a flat microphone. 1 down 2 to go.
mshilarious
Banned
COOLCAT said:
Looks fine to me.
CoolCat
Well-known member
thanks. i got a NAdy ref. mic for trading 2qty PG48...it looks like the ECM 8000.
anyway, moved all the pc stuff and wired it up, set the sound card for "recorder"..this is important to prevent feedback!!
(i'm a total 0 on this pc recording)...
anyway, it's responding to the pink noise, but I don't like the GUI much.
I'll post some graphs as soon as i figure out wht the hell i'm doing?
I'm just doing the mix position.
I believe its responding correctly, the volume makes the wave go up and down, the treble knob has it's effect.
but like i siad the chart looks generic with big chunky green triangles instead of the fine wave-file looking chart on some software packs.
add: i think its obvious now, this Allen Heath software has no resolution!
it has a line at like -98, the next line is -48! so in comparison to your graphs (mshilarious)..theres no telling if its +/- 2db...you'd have to have like 10+ db changes for the boxy green triangles to show anything.
thanks again. looks like i need some higher resolution software.
anyway, moved all the pc stuff and wired it up, set the sound card for "recorder"..this is important to prevent feedback!!
(i'm a total 0 on this pc recording)...
anyway, it's responding to the pink noise, but I don't like the GUI much.
I'll post some graphs as soon as i figure out wht the hell i'm doing?
I'm just doing the mix position.
I believe its responding correctly, the volume makes the wave go up and down, the treble knob has it's effect.
but like i siad the chart looks generic with big chunky green triangles instead of the fine wave-file looking chart on some software packs.
add: i think its obvious now, this Allen Heath software has no resolution!
it has a line at like -98, the next line is -48! so in comparison to your graphs (mshilarious)..theres no telling if its +/- 2db...you'd have to have like 10+ db changes for the boxy green triangles to show anything.
thanks again. looks like i need some higher resolution software.
Attachments
Last edited:
CoolCat
Well-known member
ok, i got it. that's a very fun learning exp.
very,very cool stuff once it gets going.
the chart is fine once you get it tight +/- 6db, then i could magnify and up the chart resolution. (ignore my previous statement of the software resolution, my mistake.)
approx. 16hrs later,
TEST TOOLS: NAdy RTA mic, AllenHEath free software, old pc.
Monitors:JBL Control 5's and BW 303.
Very pumped up, the sweet cal spot was found and my ears agreed.
The details, seperation..whtever you call it..
and when i hit the Mono button it was like a vacuum to the center, frkn awesome.
A very interesting test, trying for a bit... but once it got going...very fun.
Very credible data imo.
The numbers were repeatable, the sensitivity followed everything, the treble, the bass, the turning of the speakers, moving to and from the wall, great stuff for a gearhead. (and easy...)
JBL sweet flat spot included a very small eq. Achieved about +/-4 to 6db, again with nothing past 100hz and drop off at 10-12K. Starting out with much much more. and yes the ears agreed, wow!
Even wound up putting the speakers upright which was a surprise.
Many,many things were done, some very bizarre things..luckily they didn't work.
JBL's showed a huge drop off at 100hz to non-exsistent and fairly steep roll-off at 10-12Khz.. this was the best optimization i could do.
i tried the Sub but it was frkn all over the place and would spike as if it was in a really slow feedback loop or some strange oscillation...
and also the potentiometer/volume knob on the sub didn't allow for precision adjustments either.
the 30-40hz on up would show up on the chart...but it was too dynamic, going up and down randomly?...the sub was turned off. and will be used only for "checks". I tried the sub every which way, backwards facing, in/out phase, 100hz, 60hz... crazy...but no good, couldn't control it. at least my sub, it was like digital either off or just way out of control, like 20+db oscillating spikes??
If anyone can explain it'd be great.
so JBLS' were set, plugged in some Pro music...notes taken on settings, it was nice, very nice.
but being a gearhead...and its only midnight,
i thought wht the hell!!
and got my BW303 set out of the box and wired up.
set everything flat.
and hit the Pink Noise... RTA-ville
Straight away, the BW were frkn +/- 2 to 3db all the way across from 80 to 14K!!
and even below 80hz all the freqs were showing up too!!
down to 20hz! and the high end was all there too past 14K!!
...the <100hz bass and 12-14K, maybe a 6-10db dop off..but they were there, the read indicators plotted them. These were off the page with the JBL's Control 5's.
amazing..simply amazing these BW303's. they were flat even in my drywall box room? first try. I wouldn't of believed it.
for a numbers guy like myself this was really amazing, productive, and fun. It can help fine tune the room and monitor placement if you give it 5-6 trys..or 16hrs!
my bass traps and Aurelx was already up per Ethans calculations so i didn't touch them. I did move my homemade portable traps...and yes the RTA could pick that up too.
I'm sold, this is a keeper tool for me, much more sensitivity than the handheld SPL meter....and the charts are cool, software plots it for you.
I couldn't get my cd-r going, so i couldn't post. dang, amazing...especially the BW303 chart...wow!
thanks mshilarious!! for keeping it going...
very,very cool stuff once it gets going.
the chart is fine once you get it tight +/- 6db, then i could magnify and up the chart resolution. (ignore my previous statement of the software resolution, my mistake.)
approx. 16hrs later,
TEST TOOLS: NAdy RTA mic, AllenHEath free software, old pc.
Monitors:JBL Control 5's and BW 303.
Very pumped up, the sweet cal spot was found and my ears agreed.
The details, seperation..whtever you call it..
and when i hit the Mono button it was like a vacuum to the center, frkn awesome.
A very interesting test, trying for a bit... but once it got going...very fun.
Very credible data imo.
The numbers were repeatable, the sensitivity followed everything, the treble, the bass, the turning of the speakers, moving to and from the wall, great stuff for a gearhead. (and easy...)
JBL sweet flat spot included a very small eq. Achieved about +/-4 to 6db, again with nothing past 100hz and drop off at 10-12K. Starting out with much much more. and yes the ears agreed, wow!
Even wound up putting the speakers upright which was a surprise.
Many,many things were done, some very bizarre things..luckily they didn't work.
JBL's showed a huge drop off at 100hz to non-exsistent and fairly steep roll-off at 10-12Khz.. this was the best optimization i could do.
i tried the Sub but it was frkn all over the place and would spike as if it was in a really slow feedback loop or some strange oscillation...
and also the potentiometer/volume knob on the sub didn't allow for precision adjustments either.
the 30-40hz on up would show up on the chart...but it was too dynamic, going up and down randomly?...the sub was turned off. and will be used only for "checks". I tried the sub every which way, backwards facing, in/out phase, 100hz, 60hz... crazy...but no good, couldn't control it. at least my sub, it was like digital either off or just way out of control, like 20+db oscillating spikes??
If anyone can explain it'd be great.
so JBLS' were set, plugged in some Pro music...notes taken on settings, it was nice, very nice.
but being a gearhead...and its only midnight,
i thought wht the hell!!
and got my BW303 set out of the box and wired up.
set everything flat.
and hit the Pink Noise... RTA-ville
Straight away, the BW were frkn +/- 2 to 3db all the way across from 80 to 14K!!
and even below 80hz all the freqs were showing up too!!
down to 20hz! and the high end was all there too past 14K!!
...the <100hz bass and 12-14K, maybe a 6-10db dop off..but they were there, the read indicators plotted them. These were off the page with the JBL's Control 5's.
amazing..simply amazing these BW303's. they were flat even in my drywall box room? first try. I wouldn't of believed it.
for a numbers guy like myself this was really amazing, productive, and fun. It can help fine tune the room and monitor placement if you give it 5-6 trys..or 16hrs!
my bass traps and Aurelx was already up per Ethans calculations so i didn't touch them. I did move my homemade portable traps...and yes the RTA could pick that up too.
I'm sold, this is a keeper tool for me, much more sensitivity than the handheld SPL meter....and the charts are cool, software plots it for you.
I couldn't get my cd-r going, so i couldn't post. dang, amazing...especially the BW303 chart...wow!
thanks mshilarious!! for keeping it going...
A
applejax
New member
Sounds like its wicked stuff man... I want to test the frequency response of my room also...but dont have a flat enough mic lol 
CoolCat
Well-known member
yeah, it was right down my interest alley for the weekend.
the fact that the tool responded quickly, was repeatable was very impressive to me. whether or not a 3db is a 3db,,maybe a 4db..i don't care.
if you can try it its a gas.
like a RPM increase after after tuning the carburator!
here's an attempt for a pic. jpg.50kb. only 2qty charts....i've a bunch of them, its that easy.
the fact that the tool responded quickly, was repeatable was very impressive to me. whether or not a 3db is a 3db,,maybe a 4db..i don't care.
if you can try it its a gas.
like a RPM increase after after tuning the carburator!
here's an attempt for a pic. jpg.50kb. only 2qty charts....i've a bunch of them, its that easy.
Attachments
mshilarious
Banned
Are the JBLs 6" woofers? That looks typical. I don't know the excuse for those tweeters though. The 303s look much better, although something is strange around 1 kHz. Maybe in the crossover design.
Right around 300 Hz there is a dip in both, not as bad in the 303, but I'm wondering if that might be the room.
Right around 300 Hz there is a dip in both, not as bad in the 303, but I'm wondering if that might be the room.
CoolCat
Well-known member
yeah, JBL Control 5 plus...their White cones.."plus"
6.5". funky non-rectangular cabinets. I have the ports stuffed.
yeah, the 300hz per variables...could be the room.
man, thanks again for keeping it going, thats was much fun as buying new monitors! the first times probbaly the best too, it was invigorating.
i like your software graph, personal taste. but hell...the A&Heath was a free trial. i feel like i had a car engine tune up!
6.5". funky non-rectangular cabinets. I have the ports stuffed.
yeah, the 300hz per variables...could be the room.
man, thanks again for keeping it going, thats was much fun as buying new monitors! the first times probbaly the best too, it was invigorating.
i like your software graph, personal taste. but hell...the A&Heath was a free trial. i feel like i had a car engine tune up!
mshilarious
Banned
COOLCAT said:
Ouch! You might be better off stuffing inside the box and leaving the port open.
CoolCat
Well-known member
its not that big an issue to plug them.
one company even sends the port-plugs with their monitors.
i read somehwere to test your speakers out with the port plugged, especially if up against a wall. tightens the bass up usually, while losing a little woofy noise.
its the sealed cab vs the port thing, endless debate or preference.
there were things that didn't have a big effect and some that did, the port wasn't a big one.
one much more drastic effect noticed was the volume level.
i'm still abit confused on the db setting. is there a standard for example, -10db or -20 db...-50 db?? the volume could make the plot change considerably, i was guiessing its cancelling or adding.
and the sub was crazy? do you have a sub, dang it was all over the place for me?
and as you said "maybe its the room?" thats the coolest part of all it's my room i'm plotting...
one company even sends the port-plugs with their monitors.
i read somehwere to test your speakers out with the port plugged, especially if up against a wall. tightens the bass up usually, while losing a little woofy noise.
its the sealed cab vs the port thing, endless debate or preference.
there were things that didn't have a big effect and some that did, the port wasn't a big one.
one much more drastic effect noticed was the volume level.
i'm still abit confused on the db setting. is there a standard for example, -10db or -20 db...-50 db?? the volume could make the plot change considerably, i was guiessing its cancelling or adding.
and the sub was crazy? do you have a sub, dang it was all over the place for me?
and as you said "maybe its the room?" thats the coolest part of all it's my room i'm plotting...
mshilarious
Banned
COOLCAT said:
Yeah I do. There were a lot of interesting graphs I didn't show you before I had it right
CoolCat
Well-known member
i knew you had one...but you sound like you had to put some time in getting the sub right. i had read this on several threads, subs and small rooms.
there's no doubt the low freqs are there, but i couldn't get mine to "settle down"... more work to do on the sub.
i have the tool now to get it close. i may have to solder in a potentiometer to offer more precision on the volume knob.
i still wonder about the db scale?
i'm missing something of the procedure.
what is 0db??
it's 0db according to what? the RTA software didn't mention 85db, which i thought was standard setting?
what does 0db represent?
my testing was done at -20 -27 on the RTA software, whtever that means! ...and it was loud for me.
thought i'd add this "OEM" plot...THIS IS THE JBL CONTROL 5 official plot
there's no doubt the low freqs are there, but i couldn't get mine to "settle down"... more work to do on the sub.
i have the tool now to get it close. i may have to solder in a potentiometer to offer more precision on the volume knob.
i still wonder about the db scale?
i'm missing something of the procedure.
what is 0db??
it's 0db according to what? the RTA software didn't mention 85db, which i thought was standard setting?
what does 0db represent?
my testing was done at -20 -27 on the RTA software, whtever that means!
...and it was loud for me.thought i'd add this "OEM" plot...THIS IS THE JBL CONTROL 5 official plot
Attachments
Last edited:
CoolCat
Well-known member
heres the BW DM303 "official" graph at 1meter (3ft).
interesting test and the HR setup i used wasn't grossly off.
like you said mshilarious,
the dips or adds on both speakers are probably my room.
a good example of my confusion too...the JBL has different DB numbers than the BW on the Y axis?? the frequency/ X axis i'm cool with.
any ideas?
interesting test and the HR setup i used wasn't grossly off.
like you said mshilarious,
the dips or adds on both speakers are probably my room.
a good example of my confusion too...the JBL has different DB numbers than the BW on the Y axis?? the frequency/ X axis i'm cool with.
any ideas?
Attachments
mshilarious
Banned
COOLCAT said:what is 0db??
it's 0db according to what? the RTA software didn't mention 85db, which i thought was standard setting?
what does 0db represent?
my testing was done at -20 -27 on the RTA software, whtever that means!
0 dBFS = maximum digital signal level. What that corresponds to in dBSPL in your studio depends on the sensitivity of your mic, preamp settings, and converters.
I set my monitors at 85 dBSPL using a Radio Shack meter, then I tried to set my preamp to get the input levels to match the digital pink noise graph. If it was off a bit, I normalized it.
The BW graph Y axis is dBSPL at a fixed input level (2.83V), and a fixed distance (1m). The JBL is supposed to be the same thing, but clearly their scale has some issue
CoolCat
Well-known member
thanks, i was hoping you'd respond...after about 12 frkn searches, i was frustrated. couldn't get an answer.
i had a feeling the BW chart was more normal.
and my gut was you'd say use the SPL meter to get 85db..then run the RTA.
its making more sense now.
you got to give JBL credit tho, they don't "sugar coat" their specs. if there's a dip or spike they plot it. honesty.
i don't believe all companys are as honest....why i like to test my own stuff!
i had a feeling the BW chart was more normal.
and my gut was you'd say use the SPL meter to get 85db..then run the RTA.
its making more sense now.
you got to give JBL credit tho, they don't "sugar coat" their specs. if there's a dip or spike they plot it. honesty.
i don't believe all companys are as honest....why i like to test my own stuff!
