Form "Upload recording"
- Fields “Company or title” and “Studio” are used to rank measurements in a structure title/studio/date, date being automaticcaly written. So you can check evolution of performances in time and see any degradation. Important : do not use of company name for which you have no rights, your account may be terminated without notice.
- Field “Reference, Studio” : for home users with just one audio system, you may leave this field empty or fill with “home” or “listening room” or “without correction, “with correction”, aso. For companies with more than one studio, you may enter the Studio name.
- No accents or special characters in he fields « company » and « Reference, Studio », because those fields are used as directory names. Allowed characters are alphabets, numbers, space and underscore (_). No space or _ at start or end.
- Field “Target” : “Auto music” is recommended for HiFi/pro studios and “Auto cinema” for home-cinema. For calibration of theaters or mixing rooms, SMPTE targets maybe be used.
- “Timbre target” : the standard “Balanced” can be adjusted on user preferences to Bright (sharp, more high frequencies) or Warm (darker, more low frequencies). Difference to “Balanced” is a slope of approximatively +-0.3dB/oct (exact value depends on measurements, distances and directivity) so nearly +2dB at 10kHz for “Sharp” and -2dB at 10kHz for “Warm”.
- “LF target” : low frequency target is defined by cutoff frequency and level : hereunder “406” gives a +6dB level and a 40Hz cut. Level at 40Hz is +6-3=+3dB. Level at 130Hz is half max level so +6/2=+3dB. Note that the LF target is for each loudspeaker but the black line shows both speakers together (L+R).
It really depends on your loudspeakers. In some cases, if you want to adjust the slope of the target curve, you could change the directivity at low or high frequencies set in the form.
For reference, here are the values used for calculation :
High frequencies, Omni/Dipole/Standard/Horn = 2/5/8/12
Low frequencies, Omni/Dipole = 2/5
For stereo, the channels order is allways L R. But for multichannel setups, it is important to choose the real channel order so that the graphs show the exact channels : ie for 5.1, you can download L-C-R-LFE-Ls-Rs (movie order which is left, center, right, LFE, left surround, right surround) or L-R-C-LFE-Ls-Rs (SMPTE order). Also check which file you have downloaded : .flac files use SMPTE order (see https://xiph.org/flac/format.html ).
The whole procedure gives a calculation of the so-called “house curve”. It is based on the recording itself (ie the calculated frequency dependant reverberation time) but also on parameters you entered in the form : room volume, distance, directivities. Note that if you choose SMPTE or AES curves, those will be used as targets and no calculation adapted to your own setup.
To suit your needs, you can adjust the target with Timbre target and LF target :
- LF target choice between 209 to 803
- Timbre target sharp/balanced/warm
Those choices you can set on the Upload recording form. The timbre target slopes are not fixed but depend on your measurement. If you know that your loudspeakers are quite neutral from a high quality manufacturer, and you are quite happy with the overall soud balance, we would suggest to choose the target that is the nearest to your measured curve, ie here the “balanced” one.
An information about the target slopes : with standard loudspeakers (dome in high frequency and closed or bass-reflex box in lows) and in a mid size room, at a distance of about 3m, the bright timbre target is nearly -1.05dB/oct, the balanced is -1.4dB/oct and the warm is -1.75dB/oct. The Harman slope (see Olive in AES papers) is also about -1.75dB/oct.
Another way to have an idea about the target slope, you can use target curve calculator.
At bottom of the form in page “Upload my recording”, depending on your plan, you can choose between some options :
- “Test” gives the possibility to verify if the record is valid and if it will give correct measurements, see here.
- “Measure” starts the analysis of uploaded file to write Measurement graphs.
- “Measure and correct” adds calculation of FIR correction corresponding to your processor.
- “New correction” keeps all values of the form, so you just change “Timbre target” and/or “LF target” to reprocess. You can change the record name and upload again so you will not rewrite on old corrections and keep possibility to compare.
Page TEST p6 shows graphs Rec1 to Rec5
||Idéal curves (simulated)|
|Graph Rec2 shows detail of non synchonised record||Synchronisation is correct when value “record time lag” corresponds to max and 3 black lines are aligned to peaks.|
|Unvalid Rec1 because lines are not aligned to parts on the graph.||Valid : purple lines should be temporally separating parts.|
Depending on our server workload, it will generally take 5 to 10 minutes to get all your results. Be sure to use the refresh button to see the actual files.
For some reason, you may get not measurement graphs (don’t forget to use refresh button before complaining !). In this case, just upload your files another time.
The method is very stable. To check it, just do some successive measurements and compare.