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No relation to PMC except the cat comes from a catloving territory (UK), had to share our new cat in his favourite place on top of my Gauder Akustik speaker ...
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PMC Twenty.21 Bookshelf Speaker Review
- Thread starter amirm
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carlosmante
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Can you tell me how big was the sample size? How many independent replications were conducted and their results?
You gotta buy the book !
AudioSceptic
Major Contributor
I am astonished that someone could say that and also say this
The first para quoted defies basic logic. You don't even need any specialist knowledge to see that.
AudioSceptic
Major Contributor
That is some jump to get on there!
carlosmante
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The "Magister dixit" and "Ipse dixit" are arguments NOT accepted in a Scientific Discussion . ha ha ha ha ha. "Ad hominen" neither ha ha ha.
carlosmante
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"
Choosing a single or even a small number of “bad” loudspeakers cannot
guarantee anything. Nobody in this massive industry seems to have undertaken
a statistical study of what might be an “average” loudspeaker. The author’s
experience suggests that the performance target for almost all consumer loudspeakers
is a more-or-less fl at axial frequency response. Failure to achieve the
target performance takes all possible forms: lack of bass, excessive bass, lack of
mids, excessive mids, lack of highs, excessive highs, prominent resonances at
arbitrary frequencies, and so on. The only common feature that distinguishes
lesser products seems to be a lack of low bass." Textual from the book.
Choosing a single or even a small number of “bad” loudspeakers cannot
guarantee anything. Nobody in this massive industry seems to have undertaken
a statistical study of what might be an “average” loudspeaker. The author’s
experience suggests that the performance target for almost all consumer loudspeakers
is a more-or-less fl at axial frequency response. Failure to achieve the
target performance takes all possible forms: lack of bass, excessive bass, lack of
mids, excessive mids, lack of highs, excessive highs, prominent resonances at
arbitrary frequencies, and so on. The only common feature that distinguishes
lesser products seems to be a lack of low bass." Textual from the book.
It's all in the book.
Since it's really worth to read for anybody interested in audio I'm not going to reread the chapter for you. I can't remember though whether the results could be repeated independently. However I have not yet seen any paper stating that a non flat on axis FR is preferred by the majority of listeners, so we should stick to what we have now until it is disproven by newer scientific research.
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I find it illogical to assume anything else than flat in-room frequency response should be worth prefering in any circumstances unless the condition of the listener's ears demands compensation. After all, anything but flat amounts to deviating from what the music was indented to sound like in a non-predictible way. I'd rather hear the indented balance and move on to other tracks, if I dislike it.
Are there studies trying to correlate preference of non-flat frequency response to some sort of hearing conditions?
Are there studies trying to correlate preference of non-flat frequency response to some sort of hearing conditions?
OP
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- #331
In-room response should be smooth but sloping down. Reason is that high frequencies are directional and there is more absorption of them in a typical room. Anechoic response should be flat since reflections are not in there by definition.
If we can get the production to occur with speakers with similar response, then we are golden.
infinitesymphony
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Much of ASR's speaker review discussion revolves around acoustic research and studies done by Floyd Toole. Earlier in this thread, @Ericglo referenced a post Toole made over at AVSForum about the idea you mention. He essentially said that the engineer who built the Yamaha NS-10 and NS-1000 studio monitors designed them to have a flat power response. Unfortunately, the end result was bass light and treble heavy sound in most rooms. An in-room target curve with a downward slope helps to mitigate this result.
I believe some of the research is available online.
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What, no nice GIF animation?!) I am very disappointed!
I believe reflections should be treated differently from direct sound. Reflections are fine to have (unless you're like a 100% accuracy guy) and they cause the downward sloping FR and as a result we like downward sloping in-room FR. There is a clear cause-and-effect relation here that does not apply the other way. In other words a speaker that does downward-sloping FR + an anechoic room is a worse listening experience than a speaker with flat FR + a normal room. Headphones have zero reflections and can be designed/EQed to whatever FR yet they can never reproduce the experience of speakers.
And having majority of the sound coming in as reflections just feels wrong. It may give a flat graph on the frequency axis, but that is at how many degrees out of phase? I like to consider hypothetical worst case scenarios to see if the idea has any issue, and here the hypothetical scenario is if you are in a parking lot with reverb that go for a few seconds. Imagine you have a speaker that depends on reflections for a good-looking sound power graph. Your reverb is going to be very bright-sounding compared to a speaker with normal FR.
I used to have speakers that sounded way too bright (Paradign Atom v.1?) and I had to point the speaker backwards so the sound reflects off the wall. Better FR? Yes. Kills a lot of accuracy? Also yes.
tl;dr Good speaker should have flat on-axis anechoic and downward sloping in-room. Not just one or the other. Plus a smooth transition from the former to the latter.
(I meant to type flat on-axis anechoic but missed that the first time
)
And having majority of the sound coming in as reflections just feels wrong. It may give a flat graph on the frequency axis, but that is at how many degrees out of phase? I like to consider hypothetical worst case scenarios to see if the idea has any issue, and here the hypothetical scenario is if you are in a parking lot with reverb that go for a few seconds. Imagine you have a speaker that depends on reflections for a good-looking sound power graph. Your reverb is going to be very bright-sounding compared to a speaker with normal FR.
I used to have speakers that sounded way too bright (Paradign Atom v.1?) and I had to point the speaker backwards so the sound reflects off the wall. Better FR? Yes. Kills a lot of accuracy? Also yes.
tl;dr Good speaker should have flat on-axis anechoic and downward sloping in-room. Not just one or the other. Plus a smooth transition from the former to the latter.
(I meant to type flat on-axis anechoic but missed that the first time
)
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I thi k what many are forgettung...is that these particular speakers are not meant to be hifi. These are tools of the trade. The person at the board is not in the room...and needs to get as close to live, real, accurate representation as possible...and then add their own spin On it.
If what they hear isn't a flat response in the reproduction chain...then that soon can be way off the mark.
For hifi...anything goes. Every brand has a 'sound' or target response based on what they believe their clientele prefers. If they were all flat...we wouldnt need more than one or two manufacturers.
If what they hear isn't a flat response in the reproduction chain...then that soon can be way off the mark.
For hifi...anything goes. Every brand has a 'sound' or target response based on what they believe their clientele prefers. If they were all flat...we wouldnt need more than one or two manufacturers.
OP
- Thread Starter
- #337
That is what we look for: flat on-axis when measured anechoic and smooth downward when including reflections. Former is the on-axis in the spinorama and latter is the PIR (Predicted In-Room Response).
You cannot measure on-axis in a room without reflections.
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Yes, I gathered that from your reviews, thanks for correcting me, I should not have said in-room. But actually I was trying to make the point that I see no reason to want dips and peaks in the FR response and was wondering if it can be related to individual "frequency response of their ears" if people actually do.
That would make no sense to me, because you hear everything with the those dips. So if you hear a real non-recorded sound you hear it with those dips, and to create that with a loudspeaker you would need a perfectly flat response to reproduce it exactly the same. It wont ever be exactly the same, because the transducer is different....but it most definitely wont even be the same if the response is not flat. Maybe my train of thought is wrong though...
Due to the fact that stereo setups will affect the timbre in the 1-10 kHz range (i.e. the error when a real central placed sound source is projected by the phantom image by stereo speakers) you may prefer a slight deviation from a perfect linear response. This is to my knowledge not a standard correction made during mixing. With a "flat response" the central phantom image will have weaker energy 1-2 kHz and higher energy 2-5 kHz compared to a single centered source.
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