Vary Amplitude of logarithmic sine sweep

[PG1985]

I have a logarithmic sine frequency sweep from 20Hz-20Khz. in the duration specified by the user. I would like to vary the amplitude of the sine wave from -10dB to 70dB. The amplitude should be increased by pressing the space bar at the rate of 8dB/s and decrease at -8dB/s when space bar released. I have implemented a SubVI to change the amplitude but when I merge it with my frequency sweep VI it plays as if its noisy. Can anyone suggest how I could do the amplitude change?

[Alex.T]

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@PG1985 wrote:

I have a logarithmic sine frequency sweep from 20Hz-20Khz. in the duration specified by the user. I would like to vary the amplitude of the sine wave from -10dB to 70dB. The amplitude should be increased by pressing the space bar at the rate of 8dB/s and decrease at -8dB/s when space bar released. I have implemented a SubVI to change the amplitude but when I merge it with my frequency sweep VI it plays as if its noisy. Can anyone suggest how I could do the amplitude change?

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Hey PG1985,

It'd be very useful if you were to include a screenshot of your VI as for questions like this it can be very helpful when determining the cause of the unpredicted output. I can only determine from your post that there may be a possiblity that you haven't included any timing in your VI which would cause rapid wave amplitude attenuation and amplification; which when viewed may seem like a noisy wave. Timing is very important in an instance where user input is required as you don't want toggled input responding too fast.

I'd really like to help you with this, so I'd really appreciate it if you could reply with your VI attached!