Home Theater Forum and Systems banner
1 - 3 of 3 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter · #1 ·
Hi All,

I think I have sorted everything out and have run my first measurements. The first problem I ran into is the warning that my levels are much too low when I do the measurement. It says I have 60db of headroom. I tried with my line in turned up to full and it still was too low. Not sure if it matters or not (using radio shack spl meter with correction file loaded).

So here are the graphs of my measurements. I had a couple of questions I was hoping someone could shed some light on:

1) I am not running a sub and I know my speakers dont dig too deep so why I am seeing so much activity below 40hz?
2) Why does my dB incresae so much from 2khz to 20khz?
3) What exactly does the waterfall graph tell me? If I understand it correctly, I want the graph to drop off as much as possible towards the front?

Thansk for you help
 

Attachments

·
Registered
Joined
·
678 Posts
It doesn't look like you went through the Calibrate SPL step to tell REW what level to report as 75dB. If you set the actual volume to ~75dB, then do the Calibrate SPL to tell REW that what it hears is 75dB, the midpart of your main range should be centered at that level.

Everything above 3kHz you should probably ignore as representing a difference between your RS meter and the calibration file. The RS meters vary a lot in the higher frequencies; the generic calibration file is typical but yours could be more sensitive, giving you the higher readings. The only way to have confidence in full range measures at the higher frequencies is with an individually calibrated microphone.

I would say the same at the low end, if you were talking about a rise below ~20Hz. But yours is higher than that, so it may be real for your room.

The waterfall is not falling off as quickly as you might like. You could extend the waterfall display range, from 300msec to a larger 600msec to see what happens. What is the construction of your room? Are you in a space with very reflective surfaces?

Bill
 

·
Premium Member
Joined
·
6,711 Posts
That's not a valid measurement, with 60dB of headroom there is almost nothing getting to REW. The soundcard cal trace looks fine, though it is worth reconnecting the loopback and making sure that is still giving a flat result with sensible levels. You then need to look at the connections to the RS meter to see if there is a problem there. Make sure the meter itself is working normally, battery is OK, correct range is selected and look at the levels on the REW VU meters when you talk into the meter to check that they change.
 
1 - 3 of 3 Posts
Top