Article: Objective and Subjective Review Of My 7.1.4 Immersive Audiophile System

[Surge]

😫 but down-mixing a 5 track recording to 2 makes sense, because the 5 tracks are all taken from the stage! You can’t be dumb enough to think otherwise? Sorry to say that, again, hope I’m not offending… 

If the 5 mics are all around the venue, ok, yes, playing back on your system is better (but still not accurate, see below). But with 99.9% of recordings, all tracks are from the instruments/vocals on the stage, which is IN FRONT of the audience.

 

The reason it still isn’t ideal even if the mics are arranged around the venue is because you don’t have the same transducers. All speakers would have to be the exact same size and be arranged in the same locations as the mics. And don’t tell me that DSP will correct for mismatched drivers — it doesn’t. Not on a high-end system. A $500 active speaker with DSP, sure.

[Jud]

48 minutes ago, Surge said:

Regarding why DSP is not great, especially for music, read these articles. For a low price-high value system, DSP is great. But when you’re into Wilson Audio speakers I believe you are doing them a massive disservice by using EQ!

https://www.psaudio.com/copper/article/dealing-with-small-room-acoustics-part-one/

 

Making EQ adjustments to compensate for low-frequency room nodes is an effective technique for evening out in-room bass response. By why is it that making EQ adjustments in the stochastic zone’s frequencies is generally less significant for improving our sound? It’s because the amount of audio information here is so great that your brain operates as a filter, and ignores a lot of the information. It’s also because, as noted, the higher-frequency modes are very close together and not as severe. EQ can certainly be effective in the midrange and high frequencies to address other issues, like a speaker that’s overly bright, but it should be used judiciously so as not to degrade the overall signal integrity more than is really necessary. Be cautious to generally only adjust to reduce “gremlin peaks “rather than boost vacuous dips, for example.

 

Add to this the reality is the fact that the measurements obtained by the measurement microphone are not truly representative of what your ears are hearing. Your ears come in pairs, each in a different position to each other, whereas your measurement mic will most likely be a single omnidirectional microphone. The mic is only going to be able to give a representation of what audio signals are being put into the room. Your ears hear a much more sophistically processed and filtered stereo sound, compared to the microphone, which takes in everything and does not filter what it “hears.” (And keep in mind that different measurement mics can have different frequency responses.)

If this article were correct, reasonably flat frequency response would not be a goal of any audio system component. Your brain would just “filter” it to sound right.

 

Room nodes, etc., also contradict your statements about reproducing a concert hall in one’s own listening space.  Studios, concert halls, and other performing venues don’t have those same nodes and reflections.

 

But perhaps your brain, along with filtering out incorrect frequencies, correctly adds in the acoustics of each performing venue? Sounds tiring.

 

 

[Jud]

9 minutes ago, Surge said:

 

😫 but down-mixing a 5 track recording to 2 makes sense, because the 5 tracks are all taken from the stage!

 

Are all of these mics at the height of the concentric drivers in each of your two speakers? If not, how can height information be accurately reproduced? Is it my brain having to do the work again? This is exhausting!

[fas42]

52 minutes ago, Surge said:

Music comes from front and reverberates in the room. Just like a concert, so it is in a room.

If you have ever heard a world-class 2 channel system, it can sound like an intimate jazz club and a large concert hall. 

 

Yes. That's how it works. A capable playback setup opens up a 'window' into the recorded spaces, and your room reacts to what's coming through that window. Normally the acoustic of where the music is happening, that space beyond the speakers, is far more interesting than what your listening space is contributing, and the mind focuses on that - the illusion that is generated completely dominates what you hear.

[fas42]

43 minutes ago, Jud said:

If this article were correct, reasonably flat frequency response would not be a goal of any audio system component. Your brain would just “filter” it to sound right.

 

Room nodes, etc., also contradict your statements about reproducing a concert hall in one’s own listening space.  Studios, concert halls, and other performing venues don’t have those same nodes and reflections.

 

But perhaps your brain, along with filtering out incorrect frequencies, correctly adds in the acoustics of each performing venue? Sounds tiring.

 

 

 

Flat frequency response is a requirement that is less and less important the more accurate a system in other areas becomes - the brain is indeed a very powerful filter that adjusts for what the ear actually picks up; if this were not the case than moving around in a room while listening to a live musician playing would be a disaster, as the frequencies at successive spots go through a jumble of peaks and troughs.

[serko70]

 

In this graph, the subwoofer response looks like it's 10dB higher than the rest of the system. That's because LFE channel is boosted by 10dB according to Dolby Atmos spec in the receiver's decoder.

 

You could avoid that during measurements by adjusting the LFE parameter as below in the receiver:

 

[The Computer Audiophile]

4 hours ago, serko70 said:

 

In this graph, the subwoofer response looks like it's 10dB higher than the rest of the system. That's because LFE channel is boosted by 10dB according to Dolby Atmos spec in the receiver's decoder.

 

You could avoid that during measurements by adjusting the LFE parameter as below in the receiver:

 

Hi @serko70, I’m not sure I follow what you’re saying. There is no receiver in use, and it’s supposed to be +10 db. If I wanted it different, I could turn the subwoofer down via its volume dial or via convolution filter, but again, the + 10 db is on purpose. 

[serko70]

3 hours ago, The Computer Audiophile said:

Hi @serko70, I’m not sure I follow what you’re saying. There is no receiver in use, and it’s supposed to be +10 db. If I wanted it different, I could turn the subwoofer down via its volume dial or via convolution filter, but again, the + 10 db is on purpose. 

Were you sending sine sweep directly to the sub without an Atmos decoding receiver inbetween?

 

What I am saying (or rather trying to) is, that's not the sub's actual response or else all speaker responses would jump by 10dB below their XO points. That's the response when you measure through the LFE channel which is boosted by 10dB. My suggestion avoids that during measurements and then of course you change LFE setting back to 0dB at the end of the calibration.

[The Computer Audiophile]

5 minutes ago, serko70 said:

Were you sending sine sweep directly to the sub without an Atmos decoding receiver inbetween?

 

What I am saying (or rather trying to) is, that's not the sub's actual response or else all speaker responses would jump by 10dB below their XO points. That's the response when you measure through the LFE channel which is boosted by 10dB. My suggestion avoids that during measurements and then of course you change LFE setting back to 0dB at the end of the calibration.

 

The measurements don't go through any decoder or specific LFE channel. It's just a sweep of 12 channels. The graph you quoted is the response after 65,000 tap filter correction. 

[serko70]

Ok I understand. I was talking about consumer brand AVRs which are always inbetween during measurements and I found this solution to see the correct sub response and adjust its volume with the rest of the system.

 

But it's a fact that Dolby LFE channel is boosted by 10dB by specification to dramatize the effects recorded solely for that .1 channel (and there are not many of them) When the sub also acts as a crossed over part of speakers, it's volume will be 10dB too high. I guess because you XO them below audible range, you don't hear that:

 

https://www.dolby.com/uploadedFiles/Assets/US/Doc/Professional/38_LFE.pdf

 

 

[The Computer Audiophile]

2 minutes ago, serko70 said:

when the sub also acts as a crossed over part of speakers, it's volume will be 10dB too high. I guess because you XO them below audible range, you don't hear that.

 

Audio sent to the subwoofer, that isn't specifically for the LFE channel, is reduced by the convolution filter, so it isn't 10 dB too loud.