Added a subwoofer and it changed my high frequency response?

[cce32]

I moved my subwoofer from my HT to my 2 channel system as an experiment and the rise above 10k Hz is very unexpected (to me).

Since I don't have a preamp I used the speaker level connections if that matters, any ideas?

Thanks,
/Carl

 

[Chrispy]

You're going to have to provide a lot more details about setup/connections/measurements than that partially obscured graph.

 

[Keith_W]

I have seen that rise >10k before. By any chance, was one measurement taken without the listening sofa, and the other with the sofa?

Take a look at this:

One pair of measurements was taken in August last year, the other pair was taken a few days ago. The only difference was, slight change in microphone position, and listening sofa.

 

[cce32]

Hm, OK, good idea I'll wire it back without moving the mic to confirm.

System is WiiM pro plus to Marantz MA-700 monoblocks to Vandersteen 2Ci
The sub is HSU VTF-3

 

[Keith_W]

Try taking the measurement with/without the listening chair. You will notice a difference. Even moving the microphone forward and backward might change the measurement dramatically, depending on how reflective/absorptive it is, the angle of the cushions, etc.

 

[Duke]

I have seen that rise >10k before. By any chance, was one measurement taken without the listening sofa, and the other with the sofa?

Take a look at this:

View attachment 343807

One pair of measurements was taken in August last year, the other pair was taken a few days ago. The only difference was, slight change in microphone position, and listening sofa.

This is VERY EDUCATIONAL. That's a HUGE difference in the measured response arising from two SMALL changes in the measurement conditions. One would draw very different conclusions from these two differing sets of curves.

My mentor Earl Geddes taught me not to use in-room measurements when doing crossover design work, and the difference between those two sets of curves makes me think that one little piece of advice probably saved me from a world of frustration.

 

[LIΟN]

It's hard to tell since the screenshot is only partially visible, but a quick glance at the messurement name below suggests it's an L+R measure.
If the microphones are not centered on L and R (sound from some channels arrives faster than others), REW may see some filtering or high frequency anomalies.
Of course, what others have said makes sense.

 

[cce32]

I have not been able to recreate this, furniture, no furniture, mic position, subwoofer in the signal path or not.
Moving on... thanks for the feedback