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PLEASE someone explain calibration after reading this....!!

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Re: PLEASE someone explain calibration after reading this....!!

Postby Hugh Robjohns » Tue Jul 30, 2019 8:40 am

TNGator wrote:I just a google for SPL software and the first thing i found was this free one.

I can see the attraction of something free, but it seems to me that trying to measure the SPL in the room using a program reliant on the interface and a separate microphone that has to run on the computer alongside the DAW is just over-complicating matters.

Most people can get away with a phone app and get reasonable results for free very easily. For anyone without a suitable phone, a cheap little meter of the type I listed above is the easiest option... and in fact I much prefer to use the handheld meter to the apps in my phone for this kind of application. It's just quicker, easier and (often) more accurate!

And I say ignore the grumpy old curmudgeons! ;) The idea of establishing a reliable acoustic reference level is a very good one and helps most people to establish consistent mixes, especially when working on a project over an extended time. There is a discussion to be had about the actual reference level chosen for each situation, but we've already been through that.

Headphones are a useful tool, and some people do prefer to mix on phones rather than speakers. It does require a different skill set and some get on with it better than others. But the same idea of a reference listening level which can be recalled reliably still applies... and there is a greater danger of hearing damage when using headphones than speakers... so beware!

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Re: PLEASE someone explain calibration after reading this....!!

Postby TNGator » Tue Jul 30, 2019 10:26 am

hobbyist wrote:
TNGator wrote:
ulrichburke wrote:Dear Anyone.

So I've got a music mixing teacher saying to me I've got to calibrate my speakers. She sent me to a YouTube video and I really tried to follow it but boy..... What am I not understanding here!?!

Firstly, my computer. Windows XP SP3 using IDT High Definition Audio Codec. I'm sorry it's not a more modern windows but my DAW wouldn't work on anything else, trust me, and I'm having enough of a nightmare understanding this DAW without having to understand a more modern one. So here goes.

He downloaded an app. onto his phone to check speaker levels. I don't have a phone posh enough to do that, so I downloaded something called Praxis which I'm not pretending to understand for one moment but it says it's a sound level meter. He said it should have C-weighting and slow response. I can't find anything called C-weighting on Praxis - whatever the heck that means - but I DID find a response control and put it over halfway, which I presume is pretty slow.

He then said 'calibrate to 80db'. Now the noise of a cruising aeroplane is 85db. So does that mean I've got to have speakers that can go as loud as a cruising aeroplane (almost!) before I can mix stuff? Apart from anything else, I'm in an apartment and what's that level going to do to the neighbours?

He then said 'turn the speakers up till the pink noise level is -20db'. It doesn't matter what I do with the speakers, the reading on Praxis doesn't change. I've got the internal sound on full, the speakers on full and it's still hovering just above -100. What am I not understanding here? The speakers themselves, btw, at this point, are briefly - so I don't get lynched by the neighbours - emitting sounds loud enough for a rock concert - they're GOOD speakers - but the meter's still at just over -100. So I can't go on with the rest of the video because I can't get the meter to go up to -20 which is the first thing he tells me to do.

Then, purely by chance, I read on Google that the correct level for mixing a piece of music should be about conversation level. If it's supposed to be conversation level, why in hells' bells am I following a video that's trying to get me up to aircraft-cruising-speed sound levels!?!

Please, I WANT to do what my teacher says and calibrate everything but I am utterly beyond confused by all of this, I really am!

If anyone's interested, the 5-minute video I've been trying to follow is here.... https://www.youtube.com/watch?v=idGvZnS ... e=youtu.be

And if anyone can explain all this sound calibration business in a way this dummy can UNDERSTAND, especially the bit about 'correct level being conversation level' (Google) vs. 'calibrate your monitors to 80db' (YouTube) I promise they'll have a friend for life cos I am not getting this at all. (Including why the guy on YouTube says the reading will change if you turn your speakers up and, I promise you, the reading stays exactly the same despite any speaker volume knob turning, up OR down, if the speaker volume knob's on zero the Praxis reading's exactly the same as if the speaker volume's on max.)

Yours frustratedly

Chris.
Chris I just a google for SPL software and the first thing i found was this free one. https://spl-lab.org/products/spl-lab-so ... ndows.html? Might be worth a try before spending money on an actual SPL device.

The way I read the link was you still need to buy a hardward device and this just gives more data than a plain SPL meter does.

Ooops... Writer
I
I say ignore that alleged teacher and set up his studio without wasting money on things of low value. Use headphones if there is a question about a mix.

Oops... You're right Apologies.
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Re: PLEASE someone explain calibration after reading this....!!

Postby hobbyist » Tue Jul 30, 2019 3:38 pm

Hugh Robjohns wrote:
ulrichburke wrote:If anyone's interested, the 5-minute video I've been trying to follow is here.... https://www.youtube.com/watch?v=idGvZnS ... e=youtu.be

I've finally been able to sit down and watch this video all the way through, and I'm very pleased (and quite relieved) to see that Presonus' Rick is spot on all the way through his instructional video.

He describes an appropriate range of reference SPLs for small home studios right at the beginning, of around 78-85dB SPL, and then why he has chosen a value towards the higher end of his recommended range for his own space (the 80dB figure mentioned by the OP). Personally, I'd start that practical range lower down at 74dB... but Americans tend to have larger rooms than Europeans so it's an understandable difference! :-)

The only thing I'd really query about his whole alignment process is that he doesn't check or take any account of the panning law attenuation/boost imposed by his DAW when playing his reference pink-noise.

Where all you're aiming for is to set a local reference level, the absolute SPL figure really isn't critical so a few decibels up or down from your intended target due to the DAW's panning law probably isn't the end of the world... but he really should have mentioned the point since it could result in as much as a 6dB error.

And that's the reason why, in my first post in this thread, I recommended checking the DAW output meter reading first, once the channel pan had been set, by using the calibrated tone file, before starting the pink-noise tests!

He also used a broadband pink-noise source which I've found can give rather unreliable results in small rooms -- hence my recommendation for a band-limited calibrated pink-noise source file.

Other than those small points, the video all makes sense to me....

My brief alignment description above might be easier to follow for some... and that SOS article I linked does explain the thinking behind the idea in much more depth, and it gives practical alternative ways of achieving a local reference monitoring level.

H


74 is a lot more reasonable!
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Re: PLEASE someone explain calibration after reading this....!!

Postby ConcertinaChap » Tue Jul 30, 2019 6:33 pm

You choose what suits you. Thus I've standardised on 70dB for the volume I get using the test tones when the volume control on my Drawmer is at 12 oclock. I aim to get my mixes sounding "right" when it's at that position. Works for me, especially since nearly everything I do is acoustic. If any element of my system changes I reset to that figure so my mixes remain consistent.

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