# First graph



## KiloWatts (Jun 20, 2011)

Your expert opinions, please!









Specs: 

AKG C1000s Microphone
M-Audio Firewire 410 soundcard
Alesis MK2 monitors
No sub

My studio is treated with loads of 2x2 Auralex, and I'm in the process of building four 2x4 bass traps which will hopefully help these hollow walls.

The straight line is my soundcard. I'm not really sure how to read this, as it's my first time with the software. I'll learn more after doing another measurement with the bass traps. The line is smoothed at 1/6, and the soundcard level is offset.

So, what can you make of this? I can capture additional graphs if necessary.

Thanks for your time, and I look forward to making REW an integral part of my studio process.


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## savior sound (Nov 30, 2008)

Do you have a .cal file for the AKG mic?


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## KiloWatts (Jun 20, 2011)

No, I had to make one myself. Is there one out there?


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## savior sound (Nov 30, 2008)

I don't know of one. Do you have a SPL meter?


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## KiloWatts (Jun 20, 2011)

No SPL meter, just the mic.


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## savior sound (Nov 30, 2008)

Something seems off. You are down 25db at around 80 Hz and the drop off above 10KHz is too sharp. I'm gonna guess your mic .cal file may have something to do with it.


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## KiloWatts (Jun 20, 2011)

How do I get a correct .cal file for my mic?


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## JohnM (Apr 11, 2006)

As a start can just post a screenshot that has the mic and soundcard cal traces on it to see how they look, just tick the relevant boxes on the SPL & Phase graph (don't include the phase trace).


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## KiloWatts (Jun 20, 2011)

Forgive me... how do I get a mic cal trace?


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## JohnM (Apr 11, 2006)

Tick the box for the "Mic/Meter Cal" trace in the legend of the SPL & Phase graph, and tick the "Soundcard Cal" box to show the soundcard cal trace. If the trace selections are greyed out you have not loaded the calibration files, you do that via the Preferences window for new measurements. For measurements you have already made click the "Change Cal..." button on the measurement panel to the left of the graph.


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## KiloWatts (Jun 20, 2011)

Ah, well the problem is I don't have a Calibration file for my microphone, which is why it's greyed out. Since there isn't one for the AKG C1000S, what file should I load (and where can I find it?)


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## Wayne A. Pflughaupt (Apr 13, 2006)

If you can locate a frequency-response graph for the mic, you can create a calibration file yourself.  See here to see how to create a calibration file. Just keep in mind that your particular mic’s actual response might not be exactly like the graph the manufacturer provides. 


Regards,
Wayne


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## KiloWatts (Jun 20, 2011)

Okay, I used the following rudimentary graph I could find on the C1000s:









Also placed the mic closer to the listening position.









Doesn't seem to match the mic cal in any way shape or form. I believe everything is correct here. However, if this is _truly_ my room's response, then I'm a bit concerned - frightened even - that I've been working in this environment for so long...


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## JohnM (Apr 11, 2006)

The room response looks pretty normal, we've seen much worse. Your ears are used to the effects rooms have on sound and tune most of it out, but the variations you have below 150Hz would make it pretty tricky to mix something that would work well in other environments. Note that the response varies significantly with position, make sure you measure from where you listen. Small changes in speaker and listener placemen can have a big effect and are worth experimenting with.

The AKG mic is not well suited to use for measurement, it is a cardiod and you really need an omni. Behringer's ECM8000 is a popular choice, as is Dayton's EMM-6.


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## KiloWatts (Jun 20, 2011)

Thanks for the feedback (no pun intended). I'll look for the mics you recommended.

How much of this do you think is due to my choice of speakers (and their condition)? I'm using nearfield monitors, Alesis MK2s, approximately 5 years old. One has a small dent in the center of the speaker cone.


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## KiloWatts (Jun 20, 2011)

Alright, I finished the bass traps and installed them, and made some new measurements:









The Blue is my previous measurement. The green is the new measurement with bass traps installed. The bass traps seem to help even out the bass response some, but now I'm losing some highs.

I'll report back after I acquire a sub, and a decent omni mic and/or SPL. Thanks for the feedback, I'll be using this program more often.


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