TM1's and Presonus Firstudio .....
- Thread starter Brandon G Romanowski
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Re: TM1's and Presonus Firstudio .....
If you're referring to the coherence trace.. it's that way because there is no DUT playing down that low. If I understand your note on the screen, you're measuring the HF of a single box so what you're seeing is expected.
If you're talking about the bump at 250hz, that's likely noise in your measurement environment.
Have fun, happy measuring.
Tim Mc
If you're referring to the coherence trace.. it's that way because there is no DUT playing down that low. If I understand your note on the screen, you're measuring the HF of a single box so what you're seeing is expected.
If you're talking about the bump at 250hz, that's likely noise in your measurement environment.
Have fun, happy measuring.
Tim Mc
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Re: TM1's and Presonus Firstudio .....
The "bump" in the extreme low end response might be attributed to building structure vibration noise...air handlers not properly isolated from the building structure is a common problem. In some places I've seen outside traffic/subways do this as well.
The "bump" in the extreme low end response might be attributed to building structure vibration noise...air handlers not properly isolated from the building structure is a common problem. In some places I've seen outside traffic/subways do this as well.
Re: TM1's and Presonus Firstudio .....
I am not talking about the coherence, I am talking about the vlf magnitude. These are random traces that all have the same low frequency noise, curious if anyone else has the same problem.....
I am not talking about the coherence, I am talking about the vlf magnitude. These are random traces that all have the same low frequency noise, curious if anyone else has the same problem.....
Re: TM1's and Presonus Firstudio .....
It's very common inside buildings with poorly installed mechanical systems, see my post above.
It's very common inside buildings with poorly installed mechanical systems, see my post above.
Re: TM1's and Presonus Firstudio .....
I'm going to pay closer attention .... I have tended to ignore it for the most part because.... Well it's fairly ignorable. Thanks Arthur
I'm going to pay closer attention .... I have tended to ignore it for the most part because.... Well it's fairly ignorable. Thanks Arthur
Re: TM1's and Presonus Firstudio .....
My first thought is that it's a signal to noise ratio problem. I would assume this is happening acoustically, that is the signal from the loudspeaker in this frequency region is just not sufficiently louder than the noise to get good data. You might try increasing the SPL from the DUT if possible. Increasing the number of averages for a measurement should also help to increase S/N.
You can verify that the problem is not in the electronics with a loop back test.
My first thought is that it's a signal to noise ratio problem. I would assume this is happening acoustically, that is the signal from the loudspeaker in this frequency region is just not sufficiently louder than the noise to get good data. You might try increasing the SPL from the DUT if possible. Increasing the number of averages for a measurement should also help to increase S/N.
You can verify that the problem is not in the electronics with a loop back test.
Re: TM1's and Presonus Firstudio .....
+1. Try running about a 2 second average.