Hi all,
Preface: Take this all with a grain of salt. I don't know what I'm doing and I'm sure there will be things to tweak and improve with my measurement.
I have a JBL LSR310S along with a pair of Genelec 8030Cs. I've been curious about what the JBL LSR310S subwoofer is doing to my signal quality as I run my DAC to the sub and then sub's HPF outputs to my Genelecs. I have a MOTO M4 that I'll attempt to measure with. Of course it isn't perfect, but hopefully I can at least set a baseline looping the interface and then compare against running through the sub.
Baseline, connecting M4 output to input with balanced TRS cable:
Just by looking at the plot, I see a -115dB distortion (I don't understand why this isn't somewhere in the distortion measurement box)
Now for the sub. The first thing I realize is that with the sub's cross over bypassed, it doesn't output on the outputs at all and it plays full range through the subwoofer. So in order to get output on the output connectors, I have to engage the crossover. I'm using a 1khz test tone, so that should be ok and is more representative of the real configuration anyway. I then notice that the output signal level is quite low. On the M4's meters, I can see my -3dBFS output using most of the meter, but the return level is maybe a third of it. This is because the JBL seems to output "-10dBv" levels. This jives with the manual which says that you should set the monitors to "-10dBv" mode while using the sub. It's annoying that the sub can accept +4dBu, but can't output at that level.
But that's what we have and here is the result:
I see around -100dB distortion
Questions:
The distortion properties (in the upper left hand box) are correct and don't require my signal to be exactly at 0dBFS, right?
Is this apples to apples if the JBL case is outputting a much lower (-10dBv) signal?
I understand THD and THD+N and it seems the sub does add a decent bit of distortion and noise... right?
I must be misunderstanding N and N+D as those values don't jive with what I see in the plot for distortion. They are also inverse of the THD numbers.
What to make of this? Thanks
Preface: Take this all with a grain of salt. I don't know what I'm doing and I'm sure there will be things to tweak and improve with my measurement.
I have a JBL LSR310S along with a pair of Genelec 8030Cs. I've been curious about what the JBL LSR310S subwoofer is doing to my signal quality as I run my DAC to the sub and then sub's HPF outputs to my Genelecs. I have a MOTO M4 that I'll attempt to measure with. Of course it isn't perfect, but hopefully I can at least set a baseline looping the interface and then compare against running through the sub.
Baseline, connecting M4 output to input with balanced TRS cable:
Just by looking at the plot, I see a -115dB distortion (I don't understand why this isn't somewhere in the distortion measurement box)
Now for the sub. The first thing I realize is that with the sub's cross over bypassed, it doesn't output on the outputs at all and it plays full range through the subwoofer. So in order to get output on the output connectors, I have to engage the crossover. I'm using a 1khz test tone, so that should be ok and is more representative of the real configuration anyway. I then notice that the output signal level is quite low. On the M4's meters, I can see my -3dBFS output using most of the meter, but the return level is maybe a third of it. This is because the JBL seems to output "-10dBv" levels. This jives with the manual which says that you should set the monitors to "-10dBv" mode while using the sub. It's annoying that the sub can accept +4dBu, but can't output at that level.
But that's what we have and here is the result:
I see around -100dB distortion
Questions:
The distortion properties (in the upper left hand box) are correct and don't require my signal to be exactly at 0dBFS, right?
Is this apples to apples if the JBL case is outputting a much lower (-10dBv) signal?
I understand THD and THD+N and it seems the sub does add a decent bit of distortion and noise... right?
I must be misunderstanding N and N+D as those values don't jive with what I see in the plot for distortion. They are also inverse of the THD numbers.
What to make of this? Thanks
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