# ECM8000 + Motu Ultralite (hiqh quality preamps)



## intellijel (Apr 15, 2008)

A few thins about this setup:

1. I am using the REW and an ECM8000 to tune my bedroom studio. I understand the purpose of using an external preamp for the ECM8000 in the case that you are using a consumer grade soundcard with limited mic input. However, if I am using a Motu Ultralite whihc has a relatively high quality mic preamp with phantom power, can I just plug the ECM8000 directly into it?

2. I also read through this forum and I guess it was not clear at first but I need an SPL meter in addition to the mic in order to properly calibrate the SPL levels of my speakers? I guess this is so that REW knows what levels it is actually puttin out (e.g. if the display says 70db then that means my SPL meter is also reading 70db at the listening position ...this is to take into account any gain/attenuation stages that may be between the soundcard output and the speakers).

3. At the listening position, my ECM8000 should be pointing straight up? Is the capsule level at the same level as the tweaters?

4. Are the spl measurements made at the listening position? If so, should the mic also be pointing straight up? or pointing horzintally towards the virtual center point of the two speakers?


many thanks! REW is an excellent piece of software


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## brucek (Apr 11, 2006)

> Motu Ultralite whihc has a relatively high quality mic preamp with phantom power, can I just plug the ECM8000 directly into it?


Yep. Many here use the M-Audio products also that have proper built in mic pre-amps.



> but I need an SPL meter in addition to the mic in order to properly calibrate the SPL levels of my speakers?


Yeah, but as you say, if you feel you can roughly estimate anywhere near 75dB, then you can get away with that, then you run the REW calibrate routine and tell REW that the level set at the listening position is 75dB. If it happens to be 80db, it's OK.



> At the listening position, my ECM8000 should be pointing straight up? Is the capsule level at the same level as the tweaters?


Sure, but don't get too crazy.  It's an omni mic and as long as it's up, you're good.



> Are the spl measurements made at the listening position? If so, should the mic also be pointing straight up?


Yep.

brucek


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## Guest (May 5, 2008)

brucek said:


> Yep. Many here use the M-Audio products also that have proper built in mic pre-amps.
> 
> Yeah, but as you say, if you feel you can roughly estimate anywhere near 75dB, then you can get away with that, then you run the REW calibrate routine and tell REW that the level set at the listening position is 75dB. If it happens to be 80db, it's OK.
> 
> ...


Thanks Brucek, very useful answer.
I am measuring with my ECM8000 and REW and have noticed that the graph with the REW sweep is different when the ECM8000 is placed horizontaly or verticaly :

- horizontaly the graph under 200 hz vary from one listening place to another one meter behind. Verticaly oriented the graph is the same
- At about 4 to 7khz the level mesured is higher when the ECM 8000 is placed horizontaly.

So you do confirm that the right way is to orient it verticaly.
No worry about ceiling reverberation ?

Many thanks
Patrick

-


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## brucek (Apr 11, 2006)

Yep, vertical is the correct orientation for this mic.


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