# DSP1124, input level with RS SPL



## yam (Mar 5, 2012)

Hello,

I’ve read the bfd guides and tried to set up the DSP1124.
Everything works fine, but I have one “problem”.
The radioshack analog SPL delivers a response at 114dB.
But it is not really 114dB – the noise is to low.
The REW use correction with over 30dB for all filters and I have to set the level higher on the Sub.

In the guides there is 75-80 dB on the graphs.

The RS SPL is set up to 80dB.
Soundcard was calibrated (Behringer USB Soundcard)
The correction .cal file was used.
I’ve set the target level to 100dB and it’s ok, but why can I not get 75dB?

If I set the Sub to 75dB (with the SPL), RWE shows “to high” while check levels.

I hope, you understand, what I mean. 

Maybe the soundcard input level is too high?


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

Not really getting what you mean. If you’re saying that REW shows “high” when you check levels just before you take a measurement, all you have to do is turn down the subwoofer and try again.

Regards,
Wayne


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## yam (Mar 5, 2012)

I know. 
But if I turn the sub down, it is really quiet.

I think, I had the wrong micro level in the PC. 
In the quiet room the internal meter shows 67dB.
Have to check it.


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## EarlK (Jan 1, 2010)

yam said:


> ,,,,
> The radioshack analog SPL delivers a response at 114dB. *( I'll assume this level is observed from within REW & is not seen at the actual meter ) .*
> But it is not really 114dB – the noise is to low.
> The REW use correction with over 30dB for all filters and I have to set the level higher on the Sub. *( We'll all have to assume that means, 30db of "attenuation" ) .*
> ,,,,,


> Some advice ; You need to be more expansive with your choice of language ( if you want people to understand your dilemma ) . We're not all mind-readers here .  :rolleyesno:

>  *"Calibrate your RadioShack SPL meter" * ( so that 80 db observed at the RS SPL meter is what's displayed as 80 db on REW's software based, SPL meter ) and then try again to get workable measurements ( for your BFD filters ) .

> Also, Please read the *SPL section of the Help File .* 


:sn:


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## yam (Mar 5, 2012)

> Some advice ; You need to be more expansive with your choice of language ( if you want people to understand your dilemma ) . We're not all mind-readers here .


Of course. Sorry.
It is hard for me to find the right words/terms, because my english ist not the best.
I could write it more exactly in german - but I think, you wouldn't understand it. 

Yes - the REW internal SPL showed 114db.
The Radioshack SPL was under 70dB.

Then REW used for correction filters -30db - target level was 75dB.

I have calibrated everything, but I have forgotten to set the micro input level.


Sorry for my english.


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