Does anyone measure crossovers in subwoofers the same way DACs or amps are measured?

[elshaddai]

For subwoofers with line-level pass throughs and/or HPF crossover controls, are there measurements that show how much noise or distortion is being introduced into the signal?

For example, I have an Emotiva Airmotive SE8 Flex subwoofer. Line In/Out with 60/80/100Hz HPF. If I run the signal from my preamp to the sub and then on to my power amp, there's an audible static noise in my bookshelf speakers if I turn the preamp volume to 100%. Not audible at normal listening levels, but I don't hear it if I run the signal from premap to power amp and connect the sub via speaker-level connections.

Being inaudible, I can rationalize running the signal through the sub to get the HPF benefit, but I'm also curious what the actual impact or change to the signal is that results in the static.

 

[Sokel]

It depends.
Here's a thread about DSP x-overs:

DSP Measurements and Rising Noise Floor

In several threads related to DSP platforms I've seen requests for measurements with filters engaged. I thought it unlikely that implementing filters in a DSP would have measurable effect on noise / distortion other than the obvious change in the fundamental, however @Sokel recently mentioned...

www.audiosciencereview.com

Here's one about a dirty cheap analog one,probably similar to what older (or not) subs had.

Cheap analog electronic crossover

I've been playing lately with a very cheap analog 2-in/4-out analog crossover. Is somehow DIY but very easy to fix. To my surprise it measures very decently! (note that has been measured with the worst possible conditions,long cables soldered just to see,adapters,noisy PSU and by someone totally...

www.audiosciencereview.com

(in sub's case add some penalties for controls,pots,etc)


And here's some measurements of a nicer analog older one (better measuring rig needed for that) :

Marchand XM9 analog electronic crossover (short of) review

This is short of a review for the very old Marchand XM9 2-way crossover boards. It's a 30 years old design,probably discontinued and I got the unpopulated boards from a friend that kept them in a drawer with no use of them. Board looks like this: I used some different components,as LME...

www.audiosciencereview.com

As it seems some DSP x-overs may be infected with noise as the freqs go lower and there is where the quality speaks,as we have seen in some threads measuring DSP filters and EQ.

 

[antcollinet]

For subwoofers with line-level pass throughs and/or HPF crossover controls, are there measurements that show how much noise or distortion is being introduced into the signal?

For example, I have an Emotiva Airmotive SE8 Flex subwoofer. Line In/Out with 60/80/100Hz HPF. If I run the signal from my preamp to the sub and then on to my power amp, there's an audible static noise in my bookshelf speakers if I turn the preamp volume to 100%. Not audible at normal listening levels, but I don't hear it if I run the signal from premap to power amp and connect the sub via speaker-level connections.

Being inaudible, I can rationalize running the signal through the sub to get the HPF benefit, but I'm also curious what the actual impact or change to the signal is that results in the static.

But most likely (IMO) this extra noise is not coming from the sub electronics, but is ground noise being increased due to the (increased ground impedance in the) extra cable length from Pre to sub and back again to power amp.

I'd be using the speaker level connections.

 

[elshaddai]

It depends.
Here's a thread about DSP x-overs:

DSP Measurements and Rising Noise Floor

In several threads related to DSP platforms I've seen requests for measurements with filters engaged. I thought it unlikely that implementing filters in a DSP would have measurable effect on noise / distortion other than the obvious change in the fundamental, however @Sokel recently mentioned...

www.audiosciencereview.com

Here's one about a dirty cheap analog one,probably similar to what older (or not) subs had.

Cheap analog electronic crossover

I've been playing lately with a very cheap analog 2-in/4-out analog crossover. Is somehow DIY but very easy to fix. To my surprise it measures very decently! (note that has been measured with the worst possible conditions,long cables soldered just to see,adapters,noisy PSU and by someone totally...

www.audiosciencereview.com

(in sub's case add some penalties for controls,pots,etc)


And here's some measurements of a nicer analog older one (better measuring rig needed for that) :

Marchand XM9 analog electronic crossover (short of) review

This is short of a review for the very old Marchand XM9 2-way crossover boards. It's a 30 years old design,probably discontinued and I got the unpopulated boards from a friend that kept them in a drawer with no use of them. Board looks like this: I used some different components,as LME...

www.audiosciencereview.com

As it seems some DSP x-overs may be infected with noise as the freqs go lower and there is where the quality speaks,as we have seen in some threads measuring DSP filters and EQ.

Thank you for the links - I'll definitely check those threads out.

 

[elshaddai]

But most likely (IMO) this extra noise is not coming from the sub electronics, but is ground noise being increased due to the (increased ground impedance in the) extra cable length from Pre to sub and back again to power amp.

I'd be using the speaker level connections.

Very possible - I don't have long runs, 5-8' cables, but I suppose it all adds up. I'm using the speaker-level connections now - happy to keep that going for now.