Is it possible that the scope trigger start is when press play button in generator and stop when play in generator is stop ?

[user44455555]

Hello

Also it is usefull when in the generator can load a wav and play it. this help driver developers and also speaker developers to see if the speaker/driver is better in transients as other speakers because can compare in the scope with the loopback signal. to test there can load short snippet of sounds with kick drum. when the scope start and stop with the play button of generator then can see better whats happen.

 

[user44455555]

I ask the question because i notice strange fade in when use multitone and loopback. on tone burst loopback all look good, so i assume not that it is a problem with my sound card. maybe the fade in can switch off ?

ok burst loopback signal in scope

strange fade in when use multitone or also sine

 

[John Mulcahy]

REW fades continuous signals in and out when they start and end to avoid clicks, but that scope capture you attached shows a discontinuity so there's an error in the two tone fade in, I'll fix it in the next build.

 

[user44455555]

it seem this problem happen on all generator waves that are fade in. because i see that in sine too

 

[John Mulcahy]

The other signals I checked did not have any issue, just the two tone and three tone signals. Sine is clean.

 

[user44455555]

I get this wrong result when i use asio and 512 sample buffer

 

[John Mulcahy]

Use a bigger buffer.

 

[user44455555]

1024 is largest i can use in ASIO, problem is same curve look a little diffrent. java sound i test too, too not correct but look diffrent too. should i upload screenshots ?. with which frequency you test the sine and you see it work ?

 

[John Mulcahy]

I can see the problem with ASIO drivers and their shorter buffers. There isn't a level discontinuity, but there is a slope discontinuity. I'll use a better fade method in the next build to fix that.

 

[sm52]

I can see the problem with ASIO drivers

This is true. I cannot use an external sound card for measurements if the buffer ASIO is 512. After a second or two it crashes. And at 1024 all measurements occur normally.

 

[John Mulcahy]

I cannot use an external sound card for measurements if the buffer ASIO is 512.

That's a different problem, unrelated to the signal fading and dependent on the computer. I can measure without issues with 128-sample buffers with ASIO, though I wouldn't use such small buffers as the risk of a background OS task interfering becomes very high.

 

[user44455555]

I can see the problem with ASIO drivers and their shorter buffers. There isn't a level discontinuity, but there is a slope discontinuity. I'll use a better fade method in the next build to fix that.

Hope this is not much work, the easiest way with less work is allow to switch off the fade in. I dont think a fade in is need

 

[John Mulcahy]

If there isn't a fade the slope discontinuity at the start of the signal causes a click.

 

[user44455555]

when wave start begin at level 0(as the sine in the preview of rew do) then click i guess is create from brain. only what cause physically clicks is when a 80 hz sine begin for example at phase 179 position. then a high freq jump is create from 0 to 32767 FS (for 16 bit) which cause high freq click