jwgorman Posted January 11, 2018 Share Posted January 11, 2018 I ran Spectrum Analyzer in my hifi room tonight. This app freeware for iPhones. I used a parts express iPhone mic and tuned the tuner in between stations. This is with my Lascalas and my EV ETX15sp I had the mic at my listening position. I wouldn’t bet the farm that Spectrum Analyzer freeware is super accurate but it looks pretty good. Quote Link to comment Share on other sites More sharing options...
garyrc Posted January 11, 2018 Share Posted January 11, 2018 It would be interesting to compare this to REW, if you have a calibrated mic. The peak can't be 11025 Hz (11,025 Hz), or am I missing a decimal point? 1,102.5 Hz would be more plausible, but the yellow bar looks like 1, 330 Hz, or so, to me, and it isn't the peak! Perhaps the yellow bar is some kind of average or other measure of central tendency, that refers to the yellow 81 dB-A figure in the room??? I would not be inclined to use A weighting for measuring SPL in a music system, because it under-represents the bass. Quote Link to comment Share on other sites More sharing options...
Moderators Travis In Austin Posted January 11, 2018 Moderators Share Posted January 11, 2018 2 hours ago, jwgorman said: I ran Spectrum Analyzer in my hifi room tonight. This app freeware for iPhones. I used a parts express iPhone mic and tuned the tuner in between stations. This is with my Lascalas and my EV ETX15sp I had the mic at my listening position. I wouldn’t bet the farm that Spectrum Analyzer freeware is super accurate but it looks pretty good. Run it without the sub, and repost the results and someone could tell you how close it is. Quote Link to comment Share on other sites More sharing options...
jwgorman Posted January 11, 2018 Author Share Posted January 11, 2018 10 hours ago, garyrc said: It would be interesting to compare this to REW, if you have a calibrated mic. The peak can't be 11025 Hz (11,025 Hz), or am I missing a decimal point? 1,102.5 Hz would be more plausible, but the yellow bar looks like 1, 330 Hz, or so, to me, and it isn't the peak! Perhaps the yellow bar is some kind of average or other measure of central tendency, that refers to the yellow 81 dB-A figure in the room??? I would not be inclined to use A weighting for measuring SPL in a music system, because it under-represents the bass. I don’t have REW, but I have a couple calibrated mics. Here’s the one I used https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphone-ipad-and-android--390-810 I also have a JBL calibrated mic I could route through a mixer and into my phone. So, check me if I’m wrong here, but with respect to A scale, you’re right from an overall DB perspective, the lower freqs would be underrepresented. But looking at the Spectrum, it is being measured accurately, at least to the extent the mic/app can measure accurately. As far as the peak goes, I have no clue. I never see that freq dominate the spectrum analysis. I don’t understand that part. Quote Link to comment Share on other sites More sharing options...
garyrc Posted January 12, 2018 Share Posted January 12, 2018 8 hours ago, jwgorman said: I don’t have REW, but I have a couple calibrated mics. Here’s the one I used https://www.parts-express.com/dayton-audio-imm-6-calibrated-measurement-microphone-for-tablets-iphone-ipad-and-android--390-810 I also have a JBL calibrated mic I could route through a mixer and into my phone. So, check me if I’m wrong here, but with respect to A scale, you’re right from an overall DB perspective, the lower freqs would be underrepresented. But looking at the Spectrum, it is being measured accurately, at least to the extent the mic/app can measure accurately. As far as the peak goes, I have no clue. I never see that freq dominate the spectrum analysis. I don’t understand that part. The only place your display mentioned A weighting was the rather free floating and undocumented 81 dB-A in yellow. Maybe it is trying to tell us that the overall average SPL is 81 dB-A Maybe it "assumes" you are measuring industrial noise for which the OSHA standards use A weighting, instead of measuring a sound system intended for music and movies, for which C weighting would be more appropriate, IMO. It should tell you all this stuff somewhere ... a Manual? Online? As I have said too many times before, APA would have a cow. They want every graph to be self explanatory without reading the text, to the degree possible. You are quite right, the graph looks like it is a fair representation of what C weight would give you with La Scala and sub. Quote Link to comment Share on other sites More sharing options...
jwgorman Posted January 12, 2018 Author Share Posted January 12, 2018 Looks quite different without the sub 1 Quote Link to comment Share on other sites More sharing options...
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