Play waveform output level

Hi,
I have a Dakota PCI audio card ( http://www.frontierdesign.com/Products/Dakota ) and want to play a simple sine function with the express vi "play waveform". My problem is now, that whatever amplitude i set for the sine (from 0.1 V to 5 V), the output level is the same (always 3.6 Vrms). However, when I play a simple sine with Matlab, the output sound on my speaker changes with different amplitudes. Has anyone an idea, where the problem could be? The driver is properly installed as LabView plays all the signals i send to play waveform...
Thanks a lot in advance
Andreas

You can right-click on an Express VI and select 'Open Front Panel'. This will allow you to see how the Express VI works. In this case, it appears that the underlying VI(s) use the Normalize Waveform function which scales the Y from -1 to +1. This may be why your amplitude appears to be fixed in LabVIEW.
You can use the techniques you see inside the Express VI to create your own version of "play waveform" that leaves out the normalize step...
Now is the right time to use %^<%Y-%m-%dT%H:%M:%S%3uZ>T
If you don't hate time zones, you're not a real programmer.
"You are what you don't automate"
Inplaceness is synonymous with insidiousness

Similar Messages

Why is it that an amplitude-scaled sound does not play louder than the original sound using Play Waveform?

I don't know if I have posted this on a correct location (kinda new here).
I am trying to demonstrate the effect of multiplying a constant to a waveform. I have a sound file read by Sound File Read Simple.vi. Then I am trying to scale the amplitude of the signal by a constant number. I've tried three methods for this: the Numeric Multiplication, the express VI Scaling and Mapping, and the scaling and conversion VI of Signal Express. The waveform shows that the amplitude of the scaled signal is indeed scaled, but when played thru the play waveform VI, the sound level is still the same, no matter how much I am scaling the input. Does anyone why is this so? Also, I really wanted to show that scaling an audio waveform results in a louder waveform. How do I do this? As much as possible, I've wanted to use simple VIs as the class is an introduction to signal processing and the students (and so am I) are still finding our way into LabVIEW (we used to use MATLAB in the course).
Attachments:
scaling.vi ‏69 KB

JaymeW wrote:
Hi kirkbardini,
According to this article about Low Volume From Sound VI, you can use a scalar multiple to increase the volume of a sound saved to a .wav file, so you should be able to do this before playing it. Does that not work for you?
That information is for Labview 7.x and hence outdated. As mentioned before. Labview do a normalization before sending data to the sound card. As you know sound cards are most often 16 or 24 bits. And in most cases data input to a sound card is in DBL type. After normalization the data is converted so the floating point value 1 represent full scale output on data sent to the the sound card DA. To get any further I suggest kirkbardini take the time needed to send us his/hers current code. Then we may solve things from there
Besides which, my opinion is that Express VIs Carthage must be destroyed deleted
(Sorry no Labview "brag list" so far)

Play Waveform Express vi: How to disable "Normalize waveform"?

I am an EE professor. My students are using LabView to develop simple music synthesizers. How can we disable the "Normalize Waveform" function within the "Play Waveform" express vi, so that we can control volume with amplitude?

Since you know that Normalize Waveform.vi is inside the Express VI, you have apparently converted Play Waveform.vi to a standard VI and opened its block diagram. You can either remove Normalize or, probably better, add a boolean control and a case structure around Normalize from the Play Waveform and save with a different name.
While you are at it, change the signal inputs and outputs to arrays of waveforms (as it uses internally) and get rid of the evil Dynamic Data Type. You can use the process to teach your students better programmig pracitces while getting the Vi to perform as you want.
Lynn

Bouncing in Logic, Suppressed and Quiet Volume Output Levels

So I've just finished mixing a song from a friend's band's performance and it sounds great. The Output is hot, usually staying upwards of -3.5 decibels and less than 0 thanks to the compressor/limiter plugin and some basic volume automation. I have the computer output levels set at halfway and the master logic output set at half as well, and the mix is slightly louder than I would prefer comfort-wise in my headphones. By all means, my bounce out of logic and onto my desktop should be at a similar volume level, but it is not. In comparison to my songs in my itunes collection, the output is very significantly affected and diminished. A listener would have to turn the volume up on their stereo or computer to reach an equal volume level as their other music.
I have tried bouncing with normalization turned on and off and have bounced out both aiff and m4a files. My Compressor/limiter plugin is on, but the output never reaches clipping levels as the plugin seems to be working as it should. I have played my bounces in both Itunes (preamp in eq is at half as well) and quicktime with the volumes set at halfway, so it's not a blockhead issue of not having my volume up in those programs. Something is seriously up here, since I have tried many possibilities, my output levels are not requiring a reduction by a plugin and I have not come to a satisfying conclusion.
My overall questions are: 1) Would could possibly explain what's amiss here since nothing theoretically should be. 2) What explains the difference between the output I hear playing my mix within logic and playing the bounce in other programs such as I tunes (again I did not bonehead here and leave my volume or eq level set low in my Itunes, nor did I normalize my bounce). 3) Should I just send my Mix to an auxillary "master" channel strip, record as audio, and export it as is? I would prefer it not have to come to this. 4) Is it possible that one cannot truly master at a professional level in logic? Do I need to get some expensive plugins in addition, or perhaps an external mastering-specific program?
I would sincerely appreciate any informative answers here, Thanks

, and large reason for that is the fact that it always seems to lack any sort of conclusive solution
I think it always yields a conclusive solution.
After all, if my question was "I need to be able to play the guitar to put some guitar down" most answers would be either "You should get a guitarist who has the skills already" or "Learn to play the guitar".
A forum post is not going to suddenly impart the skills necessary to get commercial sounding mixes instantly - the commercial mixers charge a fortune for their work, largely because they are good at it!
If a mix sounds very loud while I'm bouncing in realtime, what can possibly explain a significant volume reduction in the sound file that comes out the other end onto my desktop?
You are comparing two different things. When you are hearing it in Logic, there is a playback level going through your interface and to your speakers. When you play the same audio through iTunes, you are playing through an entirely different chain - iTunes, with it's own volume control, through the system with it's own volume control, and so on. Also in iTunes, often people have all kindsof stuff switched on like EQ settings, or the audio leveller function, which is further going to change stuff.
Just remember that the "volume" you hear is more dependent on how loud your are setting various volume controls than what the contents of the file are. If you're not sure on this stuff, then probably the best way to compare your mixes to commercial stuff is to burn them to CD and play them back on the same system.
Again, I have no need to normalize at all since my mix has a loud average volume throughout without spilling over into clipping territory on the peaks.
Are you using metering? You'd probably find it useful to compare average and peak levels on your mixes, compared to average and peak levels on commercial mixes. I think you'd be surprised how "loud" commercial mixes really are - many don't have more than a few dB of dynamic range - at least in the regular pop/rock/commercial categories.
Presumably, I have exercised all the skill necessary to get a satisfyingly loud mix. If it (the mix) came out sounding exactly as it does in logic it would be louder than I would need it to be.
It's difficult to know what you are doing, but as long as you are not clipping your outputs, what Logic writes into the audio file is exactly what you are hearing when bouncing. How you then play the file back, in a completely different set of applications, is not going to let you listen at the exact same level unless you set all the affecting volume controls to match everything else. Remember, Logic is talking directly to your audio interface, not playing through OSX's system output.
So, divide your situation into two areas - am I getting my mix to the relative levels I want, and how am I playing back and hearing that mix, and go from there.

Surround encoder lowers output level of exported .wavs??

I've been playing with the surround encoder for awhile now , in Audition 1.0 and the free trial version of 3.0. I record and export 6-channel sessions as
either interleaved wav or 6 mono wavs. When I was using Audition 1.0, there was no change in channel level in the exported file versus the original recording level, i.e., if the 'Left front' channel peaks at 0dBFS during recording, so does the Left front channel of the exported file, when I re-open it in Audition or Audacity.
But with Audition 3.0, something odd is happening. All of the exported channels are -3dB or so compared to their original recording level! I.e., a track that originally peaked at 0dBFS , peaks at about -3dB FS when I reopen it after export.
I have checked that the output levels for the Surround Encoder and are all at max for each channel (and 0dB gain/cut for the master output slider). I don''t see anything in the preference settings that would account for this, I happens regardless of exporting as interleaved waved or 6 mono wavs. It does NOT happen if I record and save 2-channel audio in Edit View.
Any ideas? Did something about surround encoder export change between Audition 1.0 and 3.0?

krabapple wrote:
I don''t see anything in the preference settings that would account for this, I happens regardless of exporting as interleaved waved or 6 mono wavs. It does NOT happen if I record and save 2-channel audio in Edit View.
Any ideas? Did something about surround encoder export change between Audition 1.0 and 3.0?
No, but the mixer did. I haven't tried this, but if you go to Preferences>Multitrack and change the pan law default setting from -3dB center to L/R cut Log, the chances are that your mix will come out 3dB higher.

AppleTV distorts sound, output level too high

Hi
I have a problem and have already tried a number of solutions.
My AppleTV sound is distorted, due to the output level being too high. Initially I used the TVs headset jack-connector for connecting to my amp, and lowering the output level from the TV didn't work. It is distorted from the source (AppleTV)
Now I have bought a seperate D/A converter for connecting the AppleTVs optical output directly to my analog amplifier. Still doesn't work. Sound still distorted.
When playing music through AppleTV, I have the ability to adjust the volume level on the source device. And then everything is OK.
But airplaying video/youtube from my ipad (I do that a lot - playing kiddie-flics for my toddler) there is no option to reduce the sound level.
Effectively most content airplayed will be distorted - and I am sick of it. I have a high-end amp and speakers. I do not expect audiophile quality from the AppleTV. Still I didn't expect defective/destroyed sound... And no, the AMP isn't the issue, as this has been replaced as well, due to an upgrade. Same issue on both AMPs.
Any good suggestions? Or should I simply accept that the design criterias for the AppleTV doesn't involve a reasonable audio quality? Or is my particular product defective?
Thanks,
Claus

If the audio is clipped there's not much you can do other than re-record. But there is this: http://www.izotope.com/products/audio/RX/
-DH

Sound File Read and Express Play WaveForm.

Hi, all
I am trying to control the volume on the Play WaveForm express vi, but have not been able to make this happen. Does any one have suggestions that I can run with.
Thank you.

I have found two examples of an Audio Equalizer that controls a sound output. The first is simplified version of the second. I hope this helps!
Audio Equalizer (simplified): https://decibel.ni.com/content/docs/DOC-8435
Audio Equalizer (advanced): https://decibel.ni.com/content/docs/DOC-16037
Regards,
Jason D
Applications Engineer
National Instruments

Adjust output level of audio files in Quicktime export??

Hello...
I have been using Quicktime to create little ringtones (take an audio snippet, export as .aiff then convert to MP3 for my cell phone). However, the output of these ringtones played on my phone, compared to some other ringtones I have, is VERY loud.
I was wondering if there is a way either with Quicktime (where I export the .aiff file) or with iTunes (where I convert to MP3) that I can adjust the audio output level of the file so that it is less loud??
Thanks!!
Scott

I WAS WRONG. But there is a solution... record a screen movie using Quicktime (System 10.7 and 10.8).
Open Quicktime, in the file menu select "New Screen Recording," run your Keynote Presentation and the movie with sound will record if you use Soundflower.
Soundflower is a free program that can record system sound with QuickTime X, download at <http://cycling74.com/products/soundflower/>
In "Sound" system preference, set the output to "Soundflower (2ch)". (If you enable "Show volume in menu bar" you can Option-Click the volume icon in the menu bar to select audio devices.)
In QuickTime X's screen recording window, click the triangle near the top-right to select "Soundflower (2ch)" for the audio inout, then start recording. Keep the monitor volume slider in the recording window all the way to the left or else there will be echo on the recording.
You won't hear the sound while recording because it is going directly into QuickTime. If you beed to listen while recording, you will also need Audio Hijack Pro <http://www.rogueamoeba.com/audiohijackpro/> Hijack the application producing the sound and use the "Auxiliary Device Output" effect to send audio to "Soundflower (2ch)", then make the recording.
When using Soundflower to send audio to and from applications, you may find that you are not able to send audio through another device to monitor audio output. In such situations you can use Soundflowerbed, an application that resides in the Finder’s Menubar allowing you to tap into Soundflower channels and route them to an audio device. To start the Soundflowerbed menu app go to the Soundflower folder in /Applications and within it open Soundflowerbed.app.

Play Waveform Express VI

Hello, I am using a "Simple Read" VI to acquire a .wav file and the "Play Waveform" Express VI to play it and everything works perfectly (i.e. I can actually hear the file playing). However, when I pass the signal through a low-pass filter and connect the output to the same Express VI, I get an error. Could someone take a look at the attached VI and give me a hint of what I am doing wrong??? Thank you in advance!!!
Attachments:
Filter Exercise.vi ‏87 KB

You can convert the Express VI to a regular VI by right clicking and selecting Open Front Panel. It can then be modified. You can also provide the sampling frequency to the filter function you originally had.
Message Edited by Dennis Knutson on 03-12-2007 01:17 PM
Attachments:
Get Sample Frequency.jpg ‏19 KB

HT1222 my iphone 4S no longer plays music output to speaker after updating to version 6.1.3. I am unable to reset the phone to an earlier version! How do I get my audio output to speaker back? (music, audible, youtube, netflix))

my iphone 4S no longer plays music output to speaker after updating to version 6.1.3. I am unable to reset the phone to an earlier version! How do I get my audio output to speaker back? (music, audible, youtube, netflix)

So you have business contacts that were lost... do you not have these on a Database in some shape or form? Sounds like you need to invest in a RAID1 backup setup for your computer so you dont have this issue in the future.
As for repairing your problem, sounds like you are going to need to start from scratch at this point or if the data is still on your phone look into a program that can take the information from the phone onto iTunes.

System Sound Output Level Reset After Reboot ?

Whenever my iMac Core Duo is rebooted, system sound output level always get reset to value 0.56 (-24dB) as shown in utility "/Applications/Utilities/Audio Midi Setup". I have to increase the system sound output level to desired value of 0.75(-12.75dB) to match with built-in amplifier of Altec Lansing FX6021 speaker system. The desired setting lasts until next reboot. Is there any way I can fix the system sound output level at desired level between reboots ? Why I have to be involved in such constant struggle with the iMac for such simple audio configuration ?
Audio Hijack Pro 2.6.7 wihtout Soundflower 1.1 virtual audio device has been installed. Audio hijack function of this utility has not been used at all. Thank you for any pointer.

Thanks for the confirmation that my iMac is not an isolated case. In case you are not willing to use Audio Hijack Pro, just use Automator to create an Automator script to set system volume (In Automator's Library plane: Applications>System>Set System Volume) and save it as application. Set this application as Login Items for your account through following menu path:
System Preferences>Accounts>Login Items. Whenever you login with this account, the script will be invoked automatically by Mac OS X and sound levels for output, input and alert will be set to user preferred levels. For older versions of Mac OS X (10.3.9 and earlier) without Automator, same effect can be achieved with Apple Script, use Apple Script Editor instead of Automator to create Apple Script and set it as Login Items. This workaround has been working consistently on my iMac Intel Core Duo.
iMac Intel Core Duo 20" 2 GHz 2 GB RAM Mac OS X (10.4.7) Firewire External Drive, Belkin Wireless Router, iPod nano

Output levels

I've had a hub fitted in my car so I can connect my ipod as well as have the radio and CD. The ipod connects via the main socket at the bottom rather than the headphone jack.
This works fine except that the output level of the ipod is so much lower than the other sources that I have to turn the volume up really high and then I get all the background hum and hiss.
Is there any way to boost the output level so that I can get a cleaner sound?
Thanks
David

i don't know if you would want to but when you right click on a song>Get info> from there you can edit the volume of a song and increase it if you like by 100%.
*you can do this for multiple songs*
But occasionally the quality is decreased (although you can always edit back to the original levels)
Alex

Is it possible to get the current output level??

Is it possible to get the audio output level of a stream (in this case a mic input going through GSM compression to an RTP socket).
I would like a couple of volume bars in my application so people can see how loudly they are talking.
If anyone has any ideas on how to achieve this it would be much appreciated!
Thanks,
Dex

You want a volumeter, i am also interesting in it

Sound output level low.

I have a newer 5th generation Ipod. My old Ipod had and output level adjustment. When I dock my new Ipod I have to turn the volume on my tv up rediculously loud to hear it. Is there any way to adjust the output level??

Go to your Ipod Settings> Set Sound Check to = ON.
It a good Idea to also set Sound Check to = ON in your
ITunes program.>
Go to ITunes; Edit; Preferences and then select Playback>
Enable Sound Check;
Download or copy new program from CD and see if your levels are OK;
Hope this helps?
Compaq PC / 1GB Ipod Nano & 80GB Video Windows XP Pent 2.53 GHZ 512MHZ MB RAM 120GB HD

How to see output levels in new I-tunes?

Hello, in the old I-tunes, I used to be able to see the output levels of the files in the box where the title appears. This really helped get uniform levels between all the files. In the I-tunes I just downloaded yesterday, that option seems to be gone. Does anyone know where it went/how to access it?

Sorry, but that feature was removed in iTunes 11.
Regards.

Play waveform output level

Similar Messages

Maybe you are looking for