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Is it possible to check you have sufficient amplifier headroom with a umik-1?

Razorhelm

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I am trying to resist the urge to buy a new amplifier if i dont need it.

Is there a way to check that bass transients are being produced with out clipping using a umik-1 measuring the output of the connected speakers?

Thanks
 

abdo123

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if you click scope you can see whether the waveform is clipped or not, that might be just enough for what you need.
 

TimoJ

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UMIK-1 may clip before your amplifier unless you change UMIK-1's gain settings. That requires opening it and changing dip-switch positions, also calibration file needs sensitivity parameter change (for REW to show correct SPL).
 

abdo123

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UMIK-1 may clip before your amplifier unless you change UMIK-1's gain settings. That requires opening it and changing dip-switch positions, also calibration file needs sensitivity parameter change (for REW to show correct SPL).

you can also lower the gain via the REW settings as well, unless you're talking about higher than 100 dB SPL levels.
 
OP
Razorhelm

Razorhelm

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UMIK-1 may clip before your amplifier unless you change UMIK-1's gain settings. That requires opening it and changing dip-switch positions, also calibration file needs sensitivity parameter change (for REW to show correct SPL).
Thanks, Ill keep that in mind, I dont tend to list that loud, how much headroom should I be aiming for?
 

DVDdoug

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how much headroom should I be aiming for?
Headroom is a funny thing... If you don't use it you don't need it and if you use it, it's no longer headroom! ;)

It's too bad more amps don't have clipping indicators.

If you have sensitivity specs for your speakers you can roughly estimate the peak amplifier power you're using from the peak SPL level. i.e. approximate if you know that 3dB is a power factor of two and 10dB is a factor of 10, or you can use a spreadsheet. (i.e. If 1W is 90dB, then 93dB is 2 Watts, 96dB is 4W, and 100dB is 10 Watts, etc.) Or, does the umik-1 already come with software to do that?

This is only an approximation, as you may not know the know the sensitivity at low frequencies or the dominate frequencies in your music or the effects of your room acoustics, and you might clip your amp with deep or subsonic bass at very low SPL levels.
 

MRC01

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As the system approaches its power limits you will see increasing distortion in REW sweeps. I use the word "system" not "amp" because that increasing distortion could come from the speakers or the amp, and you won't necessarily know which. This higher distortion is part of what makes loud music sound "loud". If your system can play loud, without sounding loud, that is one sign it is clean. And as you turn up the volume, the point where it begins to sound "loud" or "strained" is likely the point where distortion is increasing.
 

Wes

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maybe just put on some ear protection and play it really loud - if it passes that, you're good

if not, then you'll need to investigate further
 

daftcombo

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This higher distortion is part of what makes loud music sound "loud".
Absolutely.
I have a question though: what is responsible for ear damage: very loud undistorted music or loud distorted music?
 

MRC01

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... I have a question though: what is responsible for ear damage: very loud undistorted music or loud distorted music?
Does that clarify? :)
The amount of distortion shouldn't matter, neither more or less dangerous. In some sense, lower distortion can be more dangerous because you can play at louder levels without realizing how loud it is. Put differently, distortion can be safer since makes it sound bad and you don't want to listen as loud.
 
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Razorhelm

Razorhelm

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Tested a bass sweep 20 to 120, at the volume I normally listen and another sweep 10db above that.
With hearing protection!

Distortion increased below 50hz at the higher volume (nothing terrible, 5% @ 40hz), so i played a 40hz tone at that volume.

The sine wave on the scope looked absolutely fine!

Thanks for your help all! Needless upgrade averted :)
 
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Razorhelm

Razorhelm

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Haha a little too late! Already tested with the sine wave but thanks now I know for next time.

The ear protection however I did use, i can replace my speakers if i fuck up but not my ears!
 

audio2design

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I am trying to resist the urge to buy a new amplifier if i dont need it.

Is there a way to check that bass transients are being produced with out clipping using a umik-1 measuring the output of the connected speakers?

Thanks

My opinion is no, and not any of the ideas recommended either because clipping is a transient event in music and the duration can be very short. It will be hard to translate what happens in an REW sweep with a transient level in music. What you think is loud in a sweep, may be below the transients you are subjecting them to during music. Detecting short term clipping outside of an amplifier is not the easiest thing to do effectively.
 

Andysu

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Haha a little too late! Already tested with the sine wave but thanks now I know for next time.

The ear protection however I did use, i can replace my speakers if i fuck up but not my ears!
Where is the video? Do the test again with you in the video cos be interesting see the measurable results.
 

Blumlein 88

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My opinion is no, and not any of the ideas recommended either because clipping is a transient event in music and the duration can be very short. It will be hard to translate what happens in an REW sweep with a transient level in music. What you think is loud in a sweep, may be below the transients you are subjecting them to during music. Detecting short term clipping outside of an amplifier is not the easiest thing to do effectively.
The tone burst test is made just for this purpose. To find the max without damaging things. Check the link in my post above.
 

audio2design

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The tone burst test is made just for this purpose. To find the max without damaging things. Check the link in my post above.

That tells you the max in a test condition, and if you are using the same source, running the test signal at full amplitude, and never adjust the gain volume knob) higher to compensate for what appears to be a quieter song, then it has merit. The op said they tested at the "volume they normally listen to". If that means volume knob position and they used the same signal source as for music and ran the test signal at 100% volume, then the test has merit. If there are difference in the signal chain gain and/or the volume was "ear-balled", then the test my not have reached the actual peak levels that would be in music.
 
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