Something I came across recently that have me concerned, not knowing what's causing it. I recently finished building a pair of speakers, and the first set of measurements I took I was using my preamp and power amp so I had to use the headphone jack on a windows 10 laptop. The FR graph has a gentle ramp up from 5K Hz. I then do the same using HDMI on my Marantz AVP with the same power amp. Then suddenly the familiar looking FR graph with a gentle slope down from around 9 Khz is back!!
I then decided to try my MacBook Pro to see if there was something caused by the windows laptop. The REW Mac version I have on it seemed goofy (I knew that from wayback), but it is dual boot, so I booted it to windows 10 and plotted the graphs again using both headphone jack to RCA and HDMI. The results are the same, that is, the HDMI has the high end slope down while the headphone jack to RCA connection/cable would ramp up. When using the HDMI I obviously had to use the Marantz AVP and the power amp, while when using Jack to RCA I was using it with a separate pure amp, but in both cases, no EQ was applied.
The two graphs are attached as I am hoping someone may have ideas as to what might have been the cause of the difference. I really don't know what else to do and which curve to trust, but I am thinking of trying the jack to RCA connection using a different jack/RCA cable, in case there is something funny go on with one cable.
Another question I am hoping someone can help me is, how do I use REW to measure the impedance of speakers?
Thank you in advance.
I then decided to try my MacBook Pro to see if there was something caused by the windows laptop. The REW Mac version I have on it seemed goofy (I knew that from wayback), but it is dual boot, so I booted it to windows 10 and plotted the graphs again using both headphone jack to RCA and HDMI. The results are the same, that is, the HDMI has the high end slope down while the headphone jack to RCA connection/cable would ramp up. When using the HDMI I obviously had to use the Marantz AVP and the power amp, while when using Jack to RCA I was using it with a separate pure amp, but in both cases, no EQ was applied.
The two graphs are attached as I am hoping someone may have ideas as to what might have been the cause of the difference. I really don't know what else to do and which curve to trust, but I am thinking of trying the jack to RCA connection using a different jack/RCA cable, in case there is something funny go on with one cable.
Another question I am hoping someone can help me is, how do I use REW to measure the impedance of speakers?
Thank you in advance.