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Anthem AVM70 Review (AV Processor)
- Thread starter amirm
- Start date
Ver.80, the latest.
Have you tried setting subwoofers to none? It may be possible that your subs in your room has room gain that happens to skew the results that just happen to have more impact on the phantom scenario.
@peng Next thing it would be cool if you could to is to measure the level or record/capture the output of the Left front, Right Front and Center pre-outs with and without phantom center, and when playing back a center channel signal only. My results were that the L and R outputs in a phantom center setup were 3 dB below the level which the center output has in a real center setup.
To simplify...
0 dB here relates to a given reference output, which could be something like 0,2V.
With center channel
L no signal
R no signal
C 0dB
Without center channel (phantom center)
L -3dB
R -3dB
C no signal
These were my own findings.
To simplify...
0 dB here relates to a given reference output, which could be something like 0,2V.
With center channel
L no signal
R no signal
C 0dB
Without center channel (phantom center)
L -3dB
R -3dB
C no signal
These were my own findings.
I can do that time permitting, but can't really see the point as -3 dB to L and R sounds like the right thing to do. I understand your point about getting 6 dB increase with L+R, and so you think since 6-3 = 3 dB, and your phantom channel did get 3 dB louder. However, that's with tons of smoothing, and on specific band only. The way I understand it, you won't get 6 dB across the board, it really depends a lot on your specific the speaker/room interaction versus frequency, and there could be a lot of room gain in the below 600 Hz (+/-) range, making it very hard to conclude anything other than just ball park numbers.
Yeah, you do get a lot more than 3 dB, whether it's exactly or almost exactly 6 dB all the way it depends on your smoothing applied as well. I noticed you used 1/2, that's a lot of smoothing, try 1/12, or at least Psy to see how it looks realistically speaking.
Here's from my REW graphs inventory, this is DLBC, that typically get much smoother response than ARCG, at least for me anyway:
In the below 300 Hz range, obviously there tend to be more room gain so for such "coherent" signal, it isn't hard to get 6 dB.
DIRAC LIVE:
ARCG:
You can see that there is in fact 4 to 6 dB in the below 300 Hz range, but less at the higher range.
If you can get 6 dB all the way, then either your speaker/room responses are much better than mine, or it is just your heavy smoothing, would like to see psy, or 1/12, even 1/6 and see how they look.
ARC
Last edited:
Here you go
These are L and R speakers without the sub. Both measured in main listening position @3 meter distance.
It's a bit tricky to avoid comb filtering when measuring two speakers together. It requires that the distance to each speaker is exactly the same, or at least within a few millimeters. The wavelength at 20 kHz is just 17 mm, and 8.5 mm difference in distance will lead to a 180 degree phase shift at 20 kHz, and a huge notch on the measurement.
The green line is with one channel inverted in REW like this:
As you said, it is interesting...
There has to be an explanation, I am glad I don't have that issue to solve, though I wish I were at your place to help troubleshoot!
As far as that 6 dB gain with two speakers, my point is the same, as @rynberg 's (would like to read his source, so as to see the details, assumptions, calculations etc), to me it really depends so I would take it as just a rule of thumb kind of deal. Case in point, the very popular peak spl online calculator that people has been linking on forums almost daily, use 3 dB, that I suppose it the right choice because for real world use, in stereo, the left/right speaker likely are non "coherent" most of the time and they want people to size their amps in more conservative way too, perhap.
By the way, if your graphs are for with subs and arcg on, that dip below 70 Hz might indicate you are not on the latest FW ver.80, just a thought, nothing to be concerned about.
On thing I just can't resist to mention, is that somehow Anthem users don't tend to measure and/or post their REW graphs. Denon/Marantz users are probably the ones who posted their REW graphs most often, tons of them can be found by a simple search. Is that the reason why so many hearsay on the internet about ARCG being so good, even better than Dirac's if you listen to the AVSF crowd, whereas Audyssey is ^*#@%+@!! Just wondering...
No subs, no ARCG on those measurements. All speaker crossovers set to "off" on these measurements.
All my speakers are (obviously) not fullrange as you can see on the rolloff below 100 Hz.
I also have FW version 80 of course.
That's nice, thanks. If you do use ARCG though, it would be a good idea to re-run it if you ran it before 80.
Interesting! You must have great speakers, based on those graphs anyway.
I wondered if you were using the sub, as it indicates "1" in that field.
