Waterfall: scale bug?

[Hannes_F]

Hi,

starting from version V4,10 but also in version V4,11 the waterfall seems to have a compressed x-axis. For example if I take a sweep from 20 to 180 Hz the waterfall will be compressed to a range from 20 to 67.5 Hz. Is this just my system or can you confirm?

Hannes

[brucek]

You can set any axis scale you wish for the waterfall with the Graph Limits button, just like a Frequency response graph.

brucek

[Hannes_F]

Thank you brucek, but that does not solve my problem unfortunately. What I mean is that the data of the waterfall are compressed to 20 - 67 Hz. Everything is there, dips and peaks, but compressed on the frequency axis. Or with other words, the waterfall ends at 67 Hz.

This is even true when I open old measurements. Right now I opened a measurement that goes up to 20 kHz, but the waterfall ends at 3 kHz.

Hannes

[brucek]

I'm not able to reproduce it.

Perhaps click the Delete Setting and Shutdown routine, and see if that clears it...

brucek

This is my first post here so first let me say that I think REW is a great program and I really appreciate the authors making this available for free.

I think I have seen what Hannes is talking about as shown below


I get this by using the minus (-) zoom when viewing a plot. Zooming back in or using the graph limits button usually fixes it. In the above graph I set the limits to 100-200 and started clicked the (-)zoom. It is more pervasive if you use wide X axis like 100-1000. I think I've seen it under other conditions but I can't recall the exact circumstances.

[Hannes_F]

Erich,

thank you for chiming in but unless you say which your original frequency response limits were it may be something else.

brucek,

here is a frequency response measured from 20 - 180 Hz of a full range monitor, no smoothing applied.



The waterfall shows all the peaks and dips but is compressed with to a range from 20 to 92 Hz.



When I switch the frequency axis to logarithmic then it looks better:



I think it is clearly a bug concerning the linear presentation of the waterfall.

Regards
Hannes



What can I do?

Hannes

[hasse_swe]

i have something like that on my laptop...
try this:
/Hasse

[Hannes_F]

hasse_swe wrote:

i have something like that on my laptop...
try this:
/Hasse

Hasse,

thank you for the reply. This double arrow hides or shows the information window but does not cure the problem.

Please somebody try this: Open a waterfall, go to Graph -> Frequency Axis Log/Linear

Is your scale still correct after that?

Hannes

[Bob_99]

I can confirm what Hannes is seeing as this is what's happening to me also. All settings appear to be correct but I didn't dig deeper than that. Interestingly enough, mine is also cutting off at 90Hz.

Also, I can confirm that the log graph is correct so it does appear to be a problem with the linear scale.

Bob

[JohnM]

There is a bug in the waterfall display when you have the frequency axis set to linear and the left hand side of the axis is below about 50Hz. I've already fixed it for the next release, but in the meantime the workaround is to use the log axis setting.

Hannes_F wrote:

Erich,

thank you for chiming in but unless you say which your original frequency response limits were it may be something else.
........................I think it is clearly a bug concerning the linear presentation of the waterfall.


Hannes

My original measurment limits were 40 to 8000 (working with full range studio monitiors)

As you mentioned, I only see teh problem using the linear scale on the x axis

[Bob_99]

JohnM wrote:

There is a bug in the waterfall display when you have the frequency axis set to linear and the left hand side of the axis is below about 50Hz. I've already fixed it for the next release, but in the meantime the workaround is to use the log axis setting.

Thank you for responding and for all your efforts in creating this program.



Bob

[brucek]

Is your scale still correct after that?

Yeah, OK I see the fault now. Good catch Hannes_F. John has it fixed for the next release.

It never came up in my beta testing since I never use LIN scale for Waterfalls.

The frequency response is in LOG, so I like to use LOG for the waterfall. Then I can move the slider back to 1 slice and see a match of my frequency response, then slowly move the slider up to 30 slices and watch the decay.

brucek

[Hannes_F]

JohnM wrote:

There is a bug in the waterfall display when you have the frequency axis set to linear and the left hand side of the axis is below about 50Hz. I've already fixed it for the next release, but in the meantime the workaround is to use the log axis setting.

Great, thank you!