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Weird Denon DRA-800H and JBL Stage A190 measurements

Nonick

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Mar 27, 2021
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This might be a better fit for Speaker subforum, but it can fit in here.
After a long and nasty SMSL AO200 story, i've acquired JBL Stage A190 speakers and (... drumroll..) Denon DRA-800H (brand new).
Decided to measure speaker response with UMIK-1 and REW.

So here's the first set of measurements:
PC > output HDMI > Denon DRA-800H (Stereo mode)
Combined left+right response
1jbldenoncombined.jpg
Left speaker response
2jbldenonleft.jpg
Right speaker response
3jbldenonright.jpg
Very strange dip on left speaker on 130 Hz. Performed multiple measurements, but the dip remains. Might be room acoustics, but the speakers were placed and measured in the same position. Performed new, though primitive, measurements. I switched Denon to Pure Direct mode.
On first set of measurement it was in Stereo mode.

New measurements with Pure Direct enabled - no dip at 130 Hz!
1) Overall measurement, distance 50 cm, on axis, Pure Direct
4jbldenonpuredirect.jpg
2) woofer, mid woofer, tweeter separate mesurements, Pure Direct. Visible crossover at cca 1.8 KHz.
5jbldenonsplitted.jpg
3) Switched to Stereo mode - no smoothing
6stereo-nosmoothing.jpg

4) Pure direct - no smoothing
7puredirect-nosmoothing.jpg

The room is bad for acoustics, no damping, speakers close to wall, so its not an ideal measurement chamber.

What concerned me before the measuring was speaker response. Listening test was performed before measurement and JBL Stage A190 was a love at first "sight".
In general,with primitive measurement methods, results are not that bad.

But the Stereo/Pure direct mode on Denon DRA-800H has serious dip problems.
Denon's transformer is buzzing as crazy (6 days old unit).
Denon DRA800H buzzing transformer noise

This might be a faulty unit or the clue for stereo/pure direct performance problems :)
P.S. this one is with PCM5102 DAC.
 

raindance

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Seems a little OCD - you won't hear the dip as it is so narrow. I highly doubt there is a fault with the amp, in all likelihood it is the SBIR frequency caused by the distance of the speaker from the wall.
 
OP
N

Nonick

Active Member
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Mar 27, 2021
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Left channel always with 130 Hz dip in stereo mode. In pure direct - theres no dip. Though it might be the buzzing of transformer that annoys me to the core ;)
 
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