I'll take your example and go back to vinyl: is what is encoded thru the vinyl the 'real message' or does it needs an inverse riaa to sound like it was intended?
That's a whole different thing ... but, if you think about it, adding RIAA emphasis during recording (which is actually to compensate for the limits of phono cartridges) needs to be cancelled out by RIAA deemphasis on playback... Why? To restore the original flat response.
I added a picture to show what I'm talking about a couple of messages back... check it out.
I don't know what picture you've got in your head about this... but that is clearly not what I'm talking about.
I'm talking about taking the mix from a source (lets say a CD) and reproducing it accurately... In order to do that you need a flat frequency response in your listening room. That flat response comes from compensating for room effects, speaker voicing and other problems so that, at the sweet spot, it's all nice and even.
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I'm not confused
If you record something with +6db of bass boost (which is not uncommon) and then play it back with +6db of bass boost on your system... how much bass boost does that give you?
Correct, it gives you 12db ... which is NOT how it was intended.
Now if you play it back with a flat response, 0db of boost... what do you get?
Correct, you get the 6db from the source recording as it was intended.
Get it now?
Once the recording is done it comes to the end user with no bass boost. It is 'just' a recording. If you play it back with 6dB bass boost then that is what it will have, not 12.
What speakers are you using that give you a flat response at listening position ? (or are you using EQ to achieve that?)
Rob.
No. It is needed to lower surface noise ( reducing snr by increasing the high content level related to intrinsic surface noise) and increase possible length to be engraved on a side ( by lowering the width of the groove where bass are : signal engraved is matrixed M/S. This is the reason you have to mono bass on vinyl you can't engrave over or through the lacquer and the reason why you can't overcompress as you risk to destroy the head). For example my cart does 5hz to 50khz native without breaking a sweat ( technics eps 310mc on SL7 obviously!
).I will take a look at the picture but this is the same situation as I explained: you compensate for an environnement needs.
Edit: Just checked your pictures but i repeat this is not what happen. Each time the loudspeaker play its fr compensate for the room interface, this doesn't add as you state. It'll be true at line level from a preamp or other line level gear however.
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Yes you do ... but you don't do it by having elevated bass or lowered treble... you do it by compensating for uneven response in the end user's listening room to provide a more or less flat response at the listening position.
YES you will be cranking up the knobs on the EQ, but you are doing it to cancel the room's errors, not to create some specific voicing of the system. In fact you are using the EQ to "devoice" the system so that the recorded source material plays as expected.
OMG ... all this time, I've been talking about using EQ and DSP to compensate for flaws in the room so that you have a flat frequency response at the listening position.
Now I just gotta ask ... What did you think I was talking about???
It is exactly what you are talking about. A speaker should only measure flat in an anechoic chamber. In a listening room it will roll off in the highs unless it has a very unusual directivity. You seem to be fixated on having a straight line on a screen which will lead to your bass and lower midrange being comprised of a lower direct signal combined with reflections from the room. You assert that having a signal that is 'pure' in the treble but in the rest of the bandwidth is a mixture of quieter original signal mixed with room reflections is actually 'closer to the original' whilst I suggest a signal without boosted treble / cut bass, low mid would be closer to the original and sound more natural.
And why isn't that line straight to begin with?
Because the acoustics of the room accent some frequencies and deplete others. There's no magic new sound there, nothing is missing, it's just that in that room the speaker needs compensation for the room's effects.
So if the room tends to accent 100hz, you turn down the 100hz slider to bring it back into line. If it depletes 12khz, you turn up the 12khz slider to bring it back into line.
Dear gawd, it's not that difficult.
Best bet ... if you want good answers and understanding, you need to study up on electronic theory a bit. AC phasing is a complex topic, not easily explained in a short forum post.
Maybe try ... All About Circuits
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Well and what about absorption of air wrt high end? Do you think a a straight line mimic the behavior of the environnement?
( this is one of the other reason most mastering engineer have this kind of downward tilt with their monitors. Search for Bob Katz's explanations about it's in house curve- minus 1,5db/octave from 1khz and up).
( this is one of the other reason most mastering engineer have this kind of downward tilt with their monitors. Search for Bob Katz's explanations about it's in house curve- minus 1,5db/octave from 1khz and up).
I'm trying to help. Nearly 20 years ago on his forum there was a guy (kui yeung wan / Thorsten ?) pushing EQ for flat response at the listening position. I had the same EQ processor as him, tried it. It sounded awful. Over the years I've measured all the speakers I've owned / built in my room and read a fair number of books. Please buy /read a copy of the Floyd Toole book I mentioned, it's the best book I've ever read on speaker stuff. (I've bought a lot of them over the last 20 years)
Basically you really shouldn't be applying any EQ above approx. 300Hz.
Rob.
No I don't.
I know it compensates for the eccentricities of the listening environment.
Now let me be perfectly clear about that ... to make that compensation may require quite the bit of EQ or DSP compensation... so while it's acoustically flat, it is not electronically so.
I really don't understand how this whole thing has devolved into, well, whatever the heck this is... It's just not that complicated.
So what would you have me do about the 800hz +7 db bulge in my listening room?
Of course I'm going to compensate for it.
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That's fine Douglas. We talk and to be honest from my side it just make me think about something else different than the health of my family members in this containment time.
Thank you for this!
And keep yourself safe. All of you mate.
I wouldn't have you do anything. You can do what ever you want
(I'm not listening to it)You still don't seem to be paying any attention to how much of the signal at listening position is direct as opposed to direct plus reflections.
If the midrange is 70 percent direct and 30 percent reflections at listening position is that how the producer intended ? ( ooh in the listeners homes they'll get this midbass quieter with some delayed reflections off the walls ceiling to make up the spl)
Rob.
I wouldn't have you do anything. You can do what ever you want
But it makes everyone sound like THIS
That's fine Douglas. We talk and to be honest from my side it just make me think about something else different than the health of my family members in this containment time.
Thank you for this!
And keep yourself safe. All of you mate.
Yep, interesting (although slightly frustrating) way to spend a Sunday Afternoon...
Stay safe...
I think that the point is that any alteration of FR should only be done once, not twice.
This was discussed several days ago and Soundbloke offered some interesting insights.
Why are professional monitor speakers designed for a flat response?
ATC +/- 2dB from about 80 to about 17k for eg. and ADAM +/- 3 from 22 to 50k
Re hearing I did a blind test in '72 and could hear a 0.25 dB change on a 1k tone, and shortly after the BBC recognised that a 0.1dB lift or cut over 4k range was audible.
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