Not even "mostly". This is completely wrong. Our ear/brain combination can sort out all these confounding aspects to a large degree. Stop making claims that are clearly wrong and people might start listening to you.
If one would like to experience how much auditory "pre-processing" the brain performs, there is a simple experiment to give you a taste. Listen to pink noise at moderate volumes with headphones for at least a half an hour. Best if you close your eyes as well. This seem to scramble the brains auditory processing of the local environment. Then take off the headphones and listen to the room. You will suddenly hear most the reflections and reverberation that your brain usually filters out. The effect will fade as your brain reestablishes the environment model.
I'd like to split whole process into three slices which can be optimized quite separately; speaker design, room acoustics and electronics. Listening setup i.e. locations of listener and speakers is not very independent slice though it's one of the main phases in optimizing process. It matches speakers with room acoustics, furniture, geometry/dimensions etc. and some subjective preferences. Electronics may need matching with speakers and listener e.g. due to some hearing issue.
Hearing is able to separate all of those slices so speakers could and should be designed properly to get whole package work. And if we design speakers properly, that helps optimizing result in different locations e.g. in some other room of the same house. This is - or at least should be very important feature with commercial products.
Automatic room EQ is quite common today. More and more people believe that smoothed in-room response is what we hear also above bass frequencies. Maybe partly because room response optimizers (separate devices or integrated in active dsp speakers) measure, visualize and equalize that without much intelligence and constraints e.g. how much and what kind of EQ is allowed for direct sound >400 Hz. Measurement is usually based on sweep with unknown smoothing width and algorithm so "visible truth" also depends on how programmer has solved that particular mathematical puzzle. Manufacturers of those devices wash their hands leaving responsibility and decisions to users who might be quite ignorant without experience what is proper sound.
It really looks that seeing of measured response is able bias understanding and listening impression what is better or worse sound.
So bentoronto is not alone with his opinions. That is okay though I don't agree with him
I don't think that this is very surprising. With headphones you get used to what noise sounds like, then you take them off and you hear the difference the room makes. Not so surprising. If the two differ dramatically then one might say that this is worse than a smaller difference, but that would need to be proven. I would hardly call it "pre-processing" though.
I keep saying this, but I guess that I'll have to say it again.I'd like to split whole process into three slices which can be optimized quite separately; speaker design, room acoustics and electronics. Listening setup i.e. locations of listener and speakers is not very independent slice though it's one of the main phases in optimizing process. It matches speakers with room acoustics, furniture, geometry/dimensions etc. and some subjective preferences. Electronics may need matching with speakers and listener e.g. due to some hearing issue.
Hearing is able to separate all of those slices so speakers could and should be designed properly to get whole package work. And if we design speakers properly, that helps optimizing result in different locations e.g. in some other room of the same house. This is - or at least should be very important feature with commercial products.
Automatic room EQ is quite common today. More and more people believe that smoothed in-room response is what we hear also above bass frequencies. Maybe partly because room response optimizers (separate devices or integrated in active dsp speakers) measure, visualize and equalize that without much intelligence and constraints e.g. how much and what kind of EQ is allowed for direct sound >400 Hz. Measurement is usually based on sweep with unknown smoothing width and algorithm so "visible truth" also depends on how programmer has solved that particular mathematical puzzle. Manufacturers of those devices wash their hands leaving responsibility and decisions to users who might be quite ignorant without experience what is proper sound.
It really looks that seeing of measured response is able bias understanding and listening impression what is better or worse sound.
So bentoronto is not alone with his opinions. That is okay though I don't agree with him
The situation is not broadband. IOW, at low frequencies the room and the speakers blend into one. The wavelengths are long and is the ears processing time so we hear a steady state sound with all the reflections etc. all blended together. But this is not the case at higher frequencies. The ear hears the transient reflection free signal and the reflections as separate events (in most cases.) One can simply not discuss the whole bandwidth of audibility as if we perceive it all the same way. Ben's belief is correct at LFs, but incorrect at HFs - the transition being room specific.
For one example, there is no benefit in finally achieving a flat anechoic response because once back in the real world, the speaker polar response will interact with the specifics of your room, drywall, windows, carpet, and furnishings to render it almost a waste of time.
can you explain what you consider flat?
Bass room gain asks for a anechoic decreasing bass response.
Reflecting surfaces asks for a small dip in the 3000khz +
Other than that the anechoic measurements helps tremendously to design a good cross over.
Measuring in room is a gamble nothing less.
can you explain what you consider flat?
Bass room gain asks for a anechoic decreasing bass response.
Reflecting surfaces asks for a small dip in the 3000khz +
Other than that the anechoic measurements helps tremendously to design a good cross over.
Measuring in room is a gamble nothing less.
So according to Linkwitz a concrete sewer under Newyork subway is good enough to play Britney Spears, wow what a revelation, enlightening is near...
yes, why make a flat response? it is pointless, lets make any response that we like to our diy speaker! a roller-coaster curve sound fun and amusing yeeeeaaa!
yes, why make a flat response? it is pointless, lets make any response that we like to our diy speaker! a roller-coaster curve sound fun and amusing yeeeeaaa!
Are you referring to equal-loudness contours? I'd think you'd want to avoid tuning a speaker for that because people play their speakers at different levels. Instead, use a treble and bass knob. Though, I'd really like to have it built into a DSP algorithm. Automatically adjust with volume level. Or have a mic that measures dB for you and adjusts the curves.
Ben are you saying that the phase difference between two drivers that are overlapping in frequency is irrelevant? Are you saying that it makes no difference if they are in phase, 10 deg out of phase, 45 deg out of phase, 90 deg out of phase or if the phase is changing at different rates for each of the two drivers?
Are you saying because of the room this becomes completely irrelevant because the phase is going to be messed up anyway?
My original comment to the OP was that good phase matching between the drivers at the crossover point (and for a distance either side) helps with driver integration. You rebutted this.
A good symetrical accoustic slope for each driver will help with driver integration, provided both drivers are operating within their comfort zones. Additionally if the crossover point is chosen well it should also help in getting an even polar response. Regardless of whether you are going for even order (drivers in phase) or odd order (Drivers 90 deg out of phase) phase matters. You cannot get the desired symetrical summing of drivers if you ignore the phase. You may be able to get something that sums flat on axis with poor phase matching between the drivers, but off axis it is likely to have some nasty surprises. These are things that room correction cannot really fix.
In room measurements are useless for trying to match phase, which is why quasi anechoic are used. Once you have designed a well behaved speaker using those quasi anechoic measurements, then you can worry about eq'ing (or not) for your particular room. If you design purely with in room measurements, then I do not believe that you can get as good a result as you will if you properly design the speaker with quality anechoic measrements, and then tweak (separate to the crossover) for your particular room.
If you don't want to go to that trouble that's your prerogative, but to tell others that well established design principals are rubbish is in no way helping the community.
Tony.
Are you saying because of the room this becomes completely irrelevant because the phase is going to be messed up anyway?
My original comment to the OP was that good phase matching between the drivers at the crossover point (and for a distance either side) helps with driver integration. You rebutted this.
A good symetrical accoustic slope for each driver will help with driver integration, provided both drivers are operating within their comfort zones. Additionally if the crossover point is chosen well it should also help in getting an even polar response. Regardless of whether you are going for even order (drivers in phase) or odd order (Drivers 90 deg out of phase) phase matters. You cannot get the desired symetrical summing of drivers if you ignore the phase. You may be able to get something that sums flat on axis with poor phase matching between the drivers, but off axis it is likely to have some nasty surprises. These are things that room correction cannot really fix.
In room measurements are useless for trying to match phase, which is why quasi anechoic are used. Once you have designed a well behaved speaker using those quasi anechoic measurements, then you can worry about eq'ing (or not) for your particular room. If you design purely with in room measurements, then I do not believe that you can get as good a result as you will if you properly design the speaker with quality anechoic measrements, and then tweak (separate to the crossover) for your particular room.
If you don't want to go to that trouble that's your prerogative, but to tell others that well established design principals are rubbish is in no way helping the community.
Tony.
no, standing waves and room size boosts bass response at some frequency
you have almost no control over this, extensive and costly sound absorbers can fix it.
As most loudspeakers have a declining bass response, the room gain compensates.
If you design a flat bass sounding speaker let say to 30 hz, it will sound with too much bass because of room gain at some bass frequencies.
BTW, even if the mix is made to sound good at normal listening level... at lower level it will become midrange-like, but this is exactly what I want. there is no need to 'equalize' my ears and brain adapts to the lower bass level perceived there. I can listen at 1 o clock no issues with neighbors.
My small speakers have a bass boost of 4 db at 90 hz and 1 db at 60 hertz,
it sound very nice with plenty of bass, even if -3db is 50 hertz, room boosts it a lot.
Siegfried Linkwitz said if a room is good enough to hold a conversation in it's good enough for music reproduction
I made a similar statement over 15 years ago, but discovered quite soon that those are just empty words even for my own subjective preferences
So that statement could reveal just "level of experience and knowledge" at that moment rather than final personal opinion based on adequate investigations. Worthless as generalization anyway.
Hi Allen, Nothing I can specifically link to, but it has been a key point in many of the things I have read about crossover design over the years.
More anecdotally from my own experiences, when I have had poor phase matching (but reasonable on axis response) the sound has not been right, but when I have redone the crossover to have good phase matching and a relatively symetrical reverse null, the sound has significantly improved.
It would be interesting to go back to some of those older designs and do comparitive off axis measurements of the speaker using the various crossovers to see how the phase differences affect the off axis response.
I know at times it is possible to "fill in" for a driver by using asymetrical slopes and this can work quite well, there are many "tricks" one can use when things are not necessarily ideal. But in my experience, setting an acoustic target and lining up with it generally gives the best results.
Tony.
More anecdotally from my own experiences, when I have had poor phase matching (but reasonable on axis response) the sound has not been right, but when I have redone the crossover to have good phase matching and a relatively symetrical reverse null, the sound has significantly improved.
It would be interesting to go back to some of those older designs and do comparitive off axis measurements of the speaker using the various crossovers to see how the phase differences affect the off axis response.
I know at times it is possible to "fill in" for a driver by using asymetrical slopes and this can work quite well, there are many "tricks" one can use when things are not necessarily ideal. But in my experience, setting an acoustic target and lining up with it generally gives the best results.
Tony.
But not at every location in the room, you get higher low frequency volumes in some locations and less in others, correct?
It looks like this video. YouTube
Standing waves are caused by the physical length of the sound wave and the room boundaries. So it's not really gain. It's amplitude peaks and dips in different room locations. You could stand in an amplitude peak and think you have gain but you're just standing in a peak. If you moved to a node in the room you'd hear a dip, just like if you were standing in the pool the water level would seem to stand still.
My personal experience with measurements and multiway-dsp speakers has teached me to
- set quasi-anechoic response to almost flat on-axis, with some compensation for off-axis problems
- find best location for speakers and spot in the room (use measurements and listening)
- adjust tonal balance to your liking at spot by doing low-Q corrections
- don't do any "room-EQ" with high-Q based on measurements!
We are accustomed to hearing tonal changes and room modes, they happen all the time without music or measurements! If one eq's spot response flat , it will not sound good, but thin and lifeless! Recommended room curve of Toole/Harman is basically ok, but unnaturally smooth!
This is multiple point measurement at my spot, separately for L and R speaker. It is not perfect - back wall is too near behind my head, but I must live with that. Peak at 700hz is reflection from a table between speakers and spot (this is a living room, not a studio!)
- set quasi-anechoic response to almost flat on-axis, with some compensation for off-axis problems
- find best location for speakers and spot in the room (use measurements and listening)
- adjust tonal balance to your liking at spot by doing low-Q corrections
- don't do any "room-EQ" with high-Q based on measurements!
We are accustomed to hearing tonal changes and room modes, they happen all the time without music or measurements! If one eq's spot response flat , it will not sound good, but thin and lifeless! Recommended room curve of Toole/Harman is basically ok, but unnaturally smooth!
This is multiple point measurement at my spot, separately for L and R speaker. It is not perfect - back wall is too near behind my head, but I must live with that. Peak at 700hz is reflection from a table between speakers and spot (this is a living room, not a studio!)
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Phase match is worthy starting point, but it can have also few negative size effects which may need e.g. unsymmetrical phase-mismatch for cure. The most obvious harm is power response dip and DI hump at XO frequency in multi-way - especially with real-life unidirectional radiators. But the same phenomenon improves the result with real-life dipole radiators so dipole speaker benefits phase matching XO more probably that boxed. Another typical consequence is limited possibilities to improve timing with IIR filters.
Finally everything depends on (everything: ) directivity features of each radiator, c-c distance compared to listening distance and room acoustics, order of acoustical slopes etc. So forcing phase match with flat axial response ignoring everything else may not be the smartest move. Fortunately we have access to tools which are able to simulate other features i.e. reveal possible weaknesses due to "forced" phase match.
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