Darkwood Designs
Audio Level Meters by Paul Marshall
Peak Programme Meter with bar display Level Meter with Digital readout for accurate steady state measurements NEW! Level Meter with Digital readout combined with a Sine Wave Test Generator 'Analogue' BBC-style Peak Programme Meters Peak Programme Meter Special Edition for the visually impaired VU scaled peak reading meter
Peak Programme Meter with bar display
Level Meter with Digital readout for accurate steady state measurements
NEW! Level Meter with Digital readout combined with a Sine Wave Test Generator
'Analogue' BBC-style Peak Programme Meters
Peak Programme Meter Special Edition for the visually impaired
VU scaled peak reading meter
For accurate RECORDING.
I designed these audio level meter programs to allow the optimum setting of input levels for various sound recording functions, particularly for video editing. When capturing video and sound from different sources accurate level setting helps maintain a consistency of volume across various clips, and therefore eases the sound mixing.
IT DOES NOT INDICATE PLAYBACK OUTPUT LEVELS. There is no way I know to access the output from another program. This meter indicates only what is fed into the wave input channel.
To monitor playback output levels feed the wave output back into the wave input, either externally with a cable or by using the Windows Mixer if you have this option. My meters can be very useful operated in this way but for accurate work you would need to calibrate it. As an aid to calibration here is a Calibration Tone Wave File you can download*. This is a 400Hz tone recorded at a level of 4dB below Full Scale Digital. Playback this file and set up the meter so this reads '6' or +8dB on the scale, or just at the start of the red. * Right-click and 'Save Target As...' to download.
Requirements: A soundcard capable of 44.1KHz 16 bit stereo sampling is required. Windows XP, Vista or 7 recommended. It is possible to have dozens of instances of the Level Meter running simultaneously if one was mad enough. The processor load is very small.
Installation. Simply copy any of the versions to any directory you like and create a shortcut to it.
Accessing the Options. Right-click over the background area to call up the Options and About screen. Peak Hold optionally holds the maximum peaks. To reset, click the small button or click anywhere on the background area. Turn on or off from the Options screen. Other options include having a yellow middle segment and to keep the meter always on top.
Calibration. 0dB on the VU-style meter could be set to represent the absolute maximum the system can handle, the so-called FSD or full-scale-digital. There is no scale above 0 because in a digital system there is no more! Some soundcards limit before hitting the theoretical full scale output of a 16 bit ADC. In any case it is unnecessary and unwise to push the soundcard to it's absolute limit. Stay out of the red to leave a bit of headroom. (The PPM is normally set up with more headroom.)
If you find the meter doesn't seem to peak high enough, or you get distortion you may have to adjust the sensitivity. See Adjusting the Calibration for more details.
A word about Sample Rate.
This program samples at 44.1KHz 16 bit stereo. I'm often asked for a version which works at 48KHz. It is not necessary. The PPM program works independently of the program you use for recording (drivers permitting), you may use any sample-rate you wish. 44.1KHz is more than adequate for metering. More unknown is the use of my program together with recording in 24 bit sampling. If anyone has any experience please let me know.
Use of this program is free and unrestricted. However, if you find my program useful please consider making a small contribution via PayPal. If you'd rather - cheques or cash are just as acceptable. My address on request.
Watch this space - new versions or enhancements may appear.
Peak Level Meter NEW VERSION December 2009
For a long time there has been a need to work with multiple soundcards. This new version allows you to select the input device.
I only have limited hardware to test this with, so I would be grateful for any feedback.
The chosen device is stored along with the other settings in a .ini file. If you need to run multiple meters monitoring different soundcards simultaneously the easiest way is to make multiple copies of the program in separate folders, and make separate short-cuts. In this way each meter can have a meaningful name with it's own settings.
This version also includes a proper self-extracting installer/un-installer.
Download Peak Level Meter version 1.7 Installer
Latest version 1.75 2nd Jan 2010
Example set-ups
PPM features:
Fallback ballistics are accurately modelled but the attack time (eg the BBC spec of 2.5dB down for a 10ms burst) is not. Peaks as short as 1ms register accurately. The fallback time from 1 to 7 is now in line with BBC specifications, 2.5 to 3 seconds.
You may prefer a faster fallback, especially as there are the peak markers, so the fallback time can be adjusted by means of an arbitrary value entered on the options page. A value of 2 corresponds to the BBC PPM spec. Values up to 10 speed up the decay.
Mono matrix can be set to M = (A+B) - 3dB or 6dB. Traditionally the BBC have used M3, though M6 is increasingly used.
Channels can be labelled L & R or A & B.
Displays Left, Right, Mono (sum) and Stereo (difference) simultaneously.
The peak markers can be set to hold the peak. Click on the window to reset.
There is also a 20dB button. This increases the gain of of the Stereo difference indication by 20dB (10 times). M, L & R are not affected.
The colour of each bar can be set to any colour from the options screen. By default all bars are green but it possible to have, for example, red and green for A and B.
Clicking on the small button bottom-left closes the Mono & Stereo display for those where only Left & Right is wanted.
The settings can be locked. Tick the 'Lock Settings' box and enter a password which will allow un-locking. To unlock, click the 'Lock Settings' box and enter the password. This is not high security and is only intended to prevent accidental changes. THe lock can be removed by deleting the .ini file.
The 'Over' indication can be set to any level. Beware of trying to come to close to full scale digital. Some soundcards have limiters and may not reach 0dB.
Download PPM.exe version 1.6 previous version
Use of this program is free and unrestricted. However, if you find my program useful please consider making a small contribution via PayPal.
Digital Level Meter
With 0.1dB resolution readout, Ideal for accurate steady state measurements, but also has PPM ballistics.
The hold button causes the digital readout to follow the peak markers as in the picture above. In conjunction with the peak hold feature this enables transient peaks to be read accurately.
Zero is referenced to Full Scale Digital, though this can be modified with the calibration adjustment to provide some headroom as required.
Download Digital Level Meter Version 1.4 installer
Latest version 1.43 2nd Jan 2010
This version also includes a self-extracting installer/un-installer.
Download Digital Level Meter Version 1.1 older version
'Analogue' Peak Programme Meter ME12
Download PPM ME12 Version 1.5 installer
Latest version 1.56 2nd Jan 2010
In response to several requests for an analogue-style PPM along the lines of the BBC ME12/9 here is my version. Originally presented largely for nostalgia it has proved to be extremely useable!
Not quite as smooth as the real thing, but it does approximately conforms to the spec which states that for a 5kHz tone burst the meter will read as follows:
Fallback time: 2.5 - 3.0 secs fall from 7 to 1.
To operate the Post Office lever key switch click on the graphic or labels right, centre or left. If you don't want to show the switch the window can be closed down to obscure the switch but you can still double-click the display to toggle between AB and MS modes. As usual, right click to access the options.
There is also an 'Over' Led which can be set to a level of the users choice. This operates in the digital domain so is not subject to the needle ballistics and may indicate very short transients.
Some comments from users:
" ...I've compared your PPMs to hardware ones, and they're so close as to be considered identical." AC
" - by far the best displays I have ever seen for a PC screen - and very accurate too." AR
"Congratulations on your level meters, they really are stunning and as an ex BBC local radio presenter / tech op very nostalgic." GL
"Let me tell you the ppm1.42 and the others from you is my favorite vu meter for a long time. It looks like very fine and working very good without crashes on every system!" RS
"I'm just trying out your 'Analogue' PPMs, and am really impressed!" MP
"I used your PPM to set levels on playbacks into the last series of Doctor Who. If you saw the 'Weakest Link' and 'What not to wear' sequences then that was your software plus a great play-in program called Soundplant." NH
"Everyone I show your meters to absolutely loves them!" AC
“Viewing it alongside both REAL Sifam meters, RTW Vectorscope & a Chromatec display I must say it looks perfect.” - RH
"Your meters are great. Is there a version for the MAC?" - Sorry, No.
Read an article about the BBC PPM by BBC Radio Resources. You might recognise some of the pictures!
Download PPM_analogue.exe version 1.41 (zipped) older version
Audio Test Generator
Level Meter with Digital readout combined with a Sine Wave Test Generator
Generate test tones from 1 Hz up to half the sample rate and accurately measure levels.
Add frequencies to a list which can be saved and stepped through manually or automatically.
Set relative levels from -50 to 0dB. (Actual level depends on soundcard output).
Download Audio Test Version 1.1 installer
Mini PPM
The large PPM is approximately life size. As this is may be a bit large here is a smaller version. Click the push button to switch to M/S mode. There is no 20db boost button. If you don't want to switch to mono/stereo mode the window can be closed down to obscure the switch. As usual, right click to access the options. When the switch is obscured you can still change modes by double-clicking on the window.
There is no title bar on this version. You can move it by dragging anywhere on the window. To exit use the taskbar menu.
Download PPM Mini Version 1.4 installer
Latest version 1.42 2nd Jan 2010
This new version allows you to select the input device.
Download PPM mini.exe version 1.3 (zipped)
Quad PPM - A, B, M and S
Displays A, B, M and S simultaneously.
The 'Over' Led can be set to a level of the users choice. This operates in the digital domain so is not subject to the needle ballistics and may indicate very short transients.
Resizeable. From the settings screen (right-click), enter the width you require in pixels from a really tiny but fully formed 100 pixels wide up to a monster 800 pixels wide. Click OK to save the changes and then restart for the new size to take effect.
Download PPM Quad Version 1.2 installer
Latest version 1.22 2nd Jan 2010
This new version allows you to select the input device. I only have limited hardware to test this with, so I would be grateful for any feedback.
Download PPM Quad.exe Version 1.1 (zipped)
Twin Peak Programme Meters
.Seperate meters reading left & right. There is no title bar on this version. You can move it by dragging anywhere on the window, and to exit use the taskbar menu. Double-clicking reveals a button for MS mode.
Resizeable. From the settings screen (right-click) to enter the width you require in pixels from a really tiny but fully formed 100 pixels wide up to a monster 800 pixels wide. Click OK to save the changes and then restart for the new size to take effect.
Download PPM Twin Version 1.5 installer
Latest version 1.51 2nd Jan 2010
Download PPM twin.exe version 1.4 (zipped)
By special request I have created a version of the BBC PPM that can be used by a person who is blind.
It will speak numbers 1 to 7 via the wave out channel, with an alarm sound for clipping. It repeats at a rate you can fix (right-click for the settings), about 2 seconds seems reasonable. The number corresponds to the peak level (left or right) since the last time it spoke, rounded down. In other words the actual level will be a bit above the number so aim to get mainly 5’s. Strictly speaking 6 is maximum but occasional 6’s will be ok, depending on how much headroom you have set up. There is 4dB between numbers.
Alternatively there is what I call delta mode where the meter speaks only when the number changes, at a maximum rate of 0.4 secs..The speech can be toggled on & off by double-clicking on the meter, or pressing the space bar, or from the settings page. The program always starts with speech on.
The visually impaired user may need assistance from a sighted person to set this up. I will be interested to hear any ideas to make this program easier to use.
Download PPM SE VI (zipped)
VU - type scale (but reads peaks)
This is my first attempt at creating accurate meters way back in 1996. Essentially unchanged from Windows 95 it works with XP, Vista and Windows 7 too.
Note: These meters do not have the ballistics of a true VU meter. They read peak levels.
Download meterH.zip For Win95/98/ME/NT/2000/XP/Vista/7
Download meterH.zip
For Win95/98/ME/NT/2000/XP/Vista/7
If you prefer there is this vertical version.
Download meterV.zip For Win95/98/ME/NT/2000/XP/Vista/7
Download meterV.zip
Download both meters together zipped
Version History
1.3 - 16/1/2001 - At the request of users, Version 1.3 adds an (optional) yellow middle segment and an optional 'Always on Top' feature. To access the options click the right mouse button over the background area. I know this is unconventional - I want a clean display uncluttered by buttons and menus.
1.4 - 25/1/2001 - Horizontal version of above.
1.5VN - 10/9/2001 - Slimline vertical version created at users request. Stores last screen position on exit.
1.5H - 7/3/2002 - Slimline horizontal version created at users requested. Dropped the old larger versions. Tested under Windows XP and no changes necessary.
1.6V and 1.6H - Peak Hold feature added at request of several users. Reset by a small button, or just by clicking anywhere on the background. Switchable from the Options screen (right click to access)
PPM V1.0 created 4/8/2003 - Non-linear scale algorithm added. Other scaling now easily possible.
[still to do - add extra features of PPM Dual to basic PPM.]
PPM Dual V1.0 created 10/10/2003 - Simultaneous L,R,M & S displays. 'Always on top' fixed.
PPM V1.1 created 12/1/2004 - M3 or M6 switchable.
PPM Dual V1.2 created 13/2/2004 - Bars can be set to any colour.
PPM V1.3 Dual version now called just PPM - old single version dropped. M-S can be closed off. Now works 640x480 properly.
PPM V1.4 Password-protected 'Lock Settings' added. 'Always on top' fixed (always was on top!)
PPM V1.41 Fixed - Decay value now stored correctly. PPM V1.42 'db' changed to 'dB'.
PPM V1.5 Out-of-phase Mono handled correctly
PPM V1.6 - PPM Analog V1.4 - PPM Mini V1.3 - PPM Quad V1.1 - PPM Twin V1.4 Calibration accepts decimal values : PPM Analog V1.4 - Title Bar removed 21/8/6
PPM SE VI V1.5 Based on PPM 1.41 with added speech function for visually impaired user.
Digital Level Meter V1.1 Bug fix division by zero error with silence 6/4/09
© Paul Marshall 2001