Help with first rew graph
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Welcome to the Forum Kenny!
It’ll be much easier to evaluate your graph if you’ll change your horizontal and vertical axis to our standard – see this post: Getting Graphs Ready to Post
Regards,
Wayne
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Yes, it can be a little confusing your first few times. We're here to help.
It certainly sounds like you ran the routine. Once you confirmed the reading, to close the dialog box did you click "Finished" or "Cancel"?
Also, for this frequency range, make sure you chose "Use REW subwoofer cal signal" when starting the SPL calibration.
Which meter were you using to calibrate the level? Was it set to "C weighting?" Where was the range dial set?
It certainly sounds like you ran the routine. Once you confirmed the reading, to close the dialog box did you click "Finished" or "Cancel"?
Also, for this frequency range, make sure you chose "Use REW subwoofer cal signal" when starting the SPL calibration.
Which meter were you using to calibrate the level? Was it set to "C weighting?" Where was the range dial set?
When I was done I hit finished. I'm using the subwoofer cal signal. I'm using a Radioshack spl meter. Was gonna purchase an ecm8000 and probably still will, but for sub testing the rs spl should be fine? My spl was set on 70db.
I wanna get into full range Testing. I've build 8-4 inch acoustic absorbing panels for first reflections, and plan on doing corner superchunks. So learning rew is important cause I wanna do some before and afer tests.
Kenny
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I wanna get into full range Testing. I've build 8-4 inch acoustic absorbing panels for first reflections, and plan on doing corner superchunks. So learning rew is important cause I wanna do some before and afer tests.
Kenny
Posted via Mobile Device
On that scale, the highest level that the meter can register would be 76dB before it clips.
Use the 80dB setting with Radio Shack Meters.
You'll want to familiarize yourself with ETC graphs then and concern yourself with a range above 100Hz. Take a peak at this post.
brucek
Yes. The 80dB range allows more room for peaks in the response above the 75dB that you have calibrated at. When you are calibrating (Check Levels + Calibrate SPL), the needle is indeed a bit hard to read at 75dB on the 80dB range, but it isn't critical to be exact on the 75dB.
But, if you use the 70dB range, the needle is almost pegged already at 75dB, so you know the needle will be pegging during measurement.
This where a Galaxy is a bit better as it has a wider range setting, or a microphone of course where there is no range setting. The Radio Shack meters have their limitations.
brucek
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7,142 Posts
That graph looks a bit more like it. Just to clarify your setup procedure: you hit calibrate, while the tone plays adjust your system volume till the spl reads 75db then make sure the REW also shows 75db and finish.
As long as your levels are ok when you press check levels before you take a measurement sweep, the graph will be correct.
Reading the graph is fairly straight forward, you simply want your subs response to follow the blue reference line as closely as possible. The flatter your subs response, the more even the sound it produces is. Peaks will tend to drown out dips, so when listening these frequencies become more prominent while the frequencies that show dips will be much quieter and possibly not audible at all. Obviously this means your missing some of the content in the material when listening to soundtracks. Large peaks will also make the system sound boomy which can become very distracting.
BTW, it looks like your running the sweeps with your speakers on as well. You need to turn your speakers off to see the subs response to follow the blue line.
As long as your levels are ok when you press check levels before you take a measurement sweep, the graph will be correct.
Reading the graph is fairly straight forward, you simply want your subs response to follow the blue reference line as closely as possible. The flatter your subs response, the more even the sound it produces is. Peaks will tend to drown out dips, so when listening these frequencies become more prominent while the frequencies that show dips will be much quieter and possibly not audible at all. Obviously this means your missing some of the content in the material when listening to soundtracks. Large peaks will also make the system sound boomy which can become very distracting.
BTW, it looks like your running the sweeps with your speakers on as well. You need to turn your speakers off to see the subs response to follow the blue line.
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Well, it certainly looks like you could benefit from some equalization. EQ would help bring down the 40 Hz and 70 Hz peaks. Also, your extension (after EQ) only gets down to ~30 Hz, which is pretty poor for home theater (but not so bad for music). Maybe you could benefit from either a better sub, or a better location of the one you have.
Regards,
Wayne
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