AXXENTS Posted March 14 Share Posted March 14 (edited) Hi all! Quickly introducing myself: new member here, using Logic for years already. In the past this forum often turned out to be quite helpful, when I researched something specific related to Logic etc. - so a huge "thank you" to this community from my side. I couldn't find an answer to this following question, so I thought why not finally join Logic Pro Help and ask it here. 👋 Please see the screenshot below (running the latest Logic update on latest macOS): for me it seems that the Analyzer range values from Logic's Channel EQ are off by -5dB (the highest peak (0dBFS) should be visually 5dB higher than it is displayed?!) Match EQ is slightly more off and Linear Phase EQ is almost -10dB off. MultiMeter looks right, as the peak goes all the way up to 0dBFS and that's what I would expect from the EQs as well. I always wondered why I couldn't drag the range all the way up to 0 in the EQs, so that the 0dB line and the EQ "flat-line" match up, which subsequently led to this observation. Does anyone know what's going on here or if this is an expected behaviour (and why)? Thank you in advance and a good day to everybody! 🙂 Edited March 15 by AXXENTS typing correction Quote Link to comment Share on other sites More sharing options...
Solution Holger Lagerfeldt Posted March 15 Solution Share Posted March 15 It's not an error. It's most likely related to the FFT block size of the analysis. It's quite common to see exactly this behavior in various analyzers. Try taking the free Voxengo SPAN analyzer and send a 0 dBFS sine test tone through it. You'll see a similar visual "reduction" at around -5 or -6 dBFS. Same in the excellent and free TDR Prism, all in peak mode. Increase the block size in SPAN and the sine peak will begin to rise visually towards 0 dBFS, but you'll also notice how choppy the update rate becomes if you switch to e.g. white noise or a dynamic signal. Adjusting the block size isn't an option in most analyzers as they'll prioritize a smooth and useful display over a detailed but choppy one. I'm guessing the built-in analyzers in the Channel EQ, Match EQ, and Linear Phase EQ have differing processing tradeoffs, since their prime objective is EQ - not graphical analysis. Also, it depends on what type of windowing function (applied to the bin width/block size of the FFT analysis), such as Hann, Hamming, Blackman, etc. In some analyzers you can set this as well. The MultiMeter is specifically focused on analysis, but its tradeoff is a much coarser frequency resolution (notice now the sine should be a thin line but is displayed as a triangle), and it has no other processing to perform at the same time. Or it's simply offset behind the scenes or uses peak interpolation to fix it. Swings and roundabouts. 3 Quote Link to comment Share on other sites More sharing options...
AXXENTS Posted March 15 Author Share Posted March 15 @Holger Lagerfeldt Thank you Holger for your clear and detailed answer. My mind is at ease now. 😄 Quote Link to comment Share on other sites More sharing options...
Holger Lagerfeldt Posted March 15 Share Posted March 15 Cheers! I just added a bit more info related to the windowing functions of some analyzers. I've refrained from the old and annoying "use your ears, not your eyes" - until now, heh heh 😉 But I guess it's applicable. 1 Quote Link to comment Share on other sites More sharing options...
AXXENTS Posted March 15 Author Share Posted March 15 I agree to this saying. 😄 For me it's just sometimes specific questions like these rise up because I'm also interested in the science behind the tech. I didn't know about window functions of spectrum analyzers yet, so now it makes even more sense and I learned something new. Thank you again! 2 Quote Link to comment Share on other sites More sharing options...
des99 Posted March 15 Share Posted March 15 I think I can sum up many years of Logic forum questions asking something along the lines of "Are Logic's meters wrong?" (in a variety of contexts), and I've never once seen (at least I can't remember one) a solution for any case that confirms that Logic's meters are indeed wrong. More often than not, it's the user not understanding something, or something else affecting levels etc that the user didn't realise. So I think we can pretty much answer for future similar questions "Is it the meters, or me?", with, "It's probably you." in pretty much all cases... 😄 1 Quote Link to comment Share on other sites More sharing options...
AXXENTS Posted March 15 Author Share Posted March 15 @des99 Haha. Well then this topic and your answer could be the "ultimate" answer regarding all sorts of questions related to "wrong Logic meters". 😄 But that's how we learn in general, by not knowing something and asking questions. 🧐 2 1 Quote Link to comment Share on other sites More sharing options...
Holger Lagerfeldt Posted March 15 Share Posted March 15 I think it's fair to wonder about these things as it's not very intuitive exactly why it's happening. Especially once you notice that different analyzers or equalizers report different values for the same input, then it's natural to go "something must be wrong". And occasionally something is wrong, just not very often 😉 The manual completely ignores this and just says the analyzer follows the same peak values/range as the equalizer which is a bit of a stretch in reality. 3 1 Quote Link to comment Share on other sites More sharing options...
David Nahmani Posted March 15 Share Posted March 15 1 minute ago, AXXENTS said: But that's how we learn in general, by not knowing something and asking questions. 🧐 BIG yes. Definitely. 1 1 Quote Link to comment Share on other sites More sharing options...
Holger Lagerfeldt Posted March 15 Share Posted March 15 Actually I've learned the most from people asking me, as sometimes I get a question I didn't (yet) know the answer to. 4 Quote Link to comment Share on other sites More sharing options...
des99 Posted March 15 Share Posted March 15 Just now, Holger Lagerfeldt said: Actually I've learned the most from people asking me, as sometimes I get a question I didn't (yet) know the answer to. Thats a big reason I hang out here - I'm not asking questions so much (nobody tends to respond to mine anyway!) - but I learn much from things other people ask. 1 2 Quote Link to comment Share on other sites More sharing options...
David Nahmani Posted March 15 Share Posted March 15 Just now, Holger Lagerfeldt said: Actually I've learned the most from people asking me, as sometimes I get a question I didn't (yet) know the answer to. That's true too. I've learned so much from spending a good part of my life on this forum. I've learned by having to research answers as you're describing, but also a lot by reading answers to other people's questions. 3 Quote Link to comment Share on other sites More sharing options...
AXXENTS Posted March 15 Author Share Posted March 15 2 minutes ago, Holger Lagerfeldt said: Actually I've learned the most from people asking me, as sometimes I get a question I didn't (yet) know the answer to. I can definitely relate to that. 😄 1 Quote Link to comment Share on other sites More sharing options...
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