OK, I will let you off lightly with that answer. But I did want to get into some very basic acoustics that are obvious yet almost always missed.
If I aim a directional loudspeaker at a piece of carpet how much sound is absorbed? (Answer lots of it, as there are not enough details to give a numeric answer.)
Now if the carpet is to the side of the loudspeaker so that the sound waves are parallel with the carpet, how much is absorbed? (Answer almost none.)
Now if I aim the loudspeaker so that the sound waves strike at a 45 degree angle how much is absorbed relative to the straight on setup? (Answer 50%)
Why?
Most of the acoustic modeling programs only use one number for the coefficient of absorption. Most material is rated for a single number. Does anyone here know what that number is supposed to represent?
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Kindhornman, all you REALLY need in a multiway speaker system is a seriously designed and EVOLVED passive XO network. That this is so has been proven many times by the likes of BBC and some serious speaker manufacturers. Unfortunately, this is not often done for lack of knowledge, but for the manufacturers' hesitation to spend serious money on that rather than on BS marketing. Developing a good XO costs time and work, both of which translate easily into the price.
Using an electronic XO is better still, but it assumes you also have some extra amps hanging around, and that is a bit more expensive. OTOH, if done well it can produce truly stunning results, albeit at a price.
What I'd like to see is a symbiotic project from a speaker maker and an amp maker, working together to produce a well adjusted, well made joint project in form of an active speaker. It has been done many times, even from mass produceing companies such as Philips and Grundig, and it worke surprisingly well. It was the idiot public which didn't get it even one bit, because they percieved these companies as low end manufacturers. Bad news for everyone.
John will say his piece, but in my view an electronic XO of formidable quality could be made with op amps. Just about every electronc XO I ever saw and heard was made using op amps, some were also very well thought out. But keep the power amps discrete, please, it's a different ball game, in their case you need to work with serious currents.
Using an electronic XO is better still, but it assumes you also have some extra amps hanging around, and that is a bit more expensive. OTOH, if done well it can produce truly stunning results, albeit at a price.
What I'd like to see is a symbiotic project from a speaker maker and an amp maker, working together to produce a well adjusted, well made joint project in form of an active speaker. It has been done many times, even from mass produceing companies such as Philips and Grundig, and it worke surprisingly well. It was the idiot public which didn't get it even one bit, because they percieved these companies as low end manufacturers. Bad news for everyone.
John will say his piece, but in my view an electronic XO of formidable quality could be made with op amps. Just about every electronc XO I ever saw and heard was made using op amps, some were also very well thought out. But keep the power amps discrete, please, it's a different ball game, in their case you need to work with serious currents.
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While I agree some magazines do try very hard, and kudos to them for it, let me ask you a simple question, SY, and upon my word, it's no provocation - when was the last time you saw manufacturer's spec based on full IHF standards? I ask because I happen to know that IHF requires an amp to be driven at 33% of its nominal power (where it's least efficient if class AB) for 30 minutes before you go for full power measurements. In all sincerity, take a wild pot shot guess at what percentage of all amps sold today would pass the 30 minute warm-up test with no overhat protection firing? I don't know exactly either, but if I were to guess, I'd say less than 10%. Just look at the crap they call "heat sinks" these days. I'v tried the 30 minute warm up with quite a number of strictly consumer electronics (integrated amps, receivers) and NONE, literally NOT ONE passed it. Including Harman/Kardon's products.
There is no point in having any standards if the manufacturer is not obliged to use them, while beinf free to add their own data in any other way they like in addition. In my view, the FTC should make declarations as per the IHF standard mandatory, think what you like, but do it, or no go to the market, period. No buts, no ifs, no maybes. And they feel like being funny, stiff penalities will soon tech them that it ain't no joke.
The Germans, with their DIN 45500, for its shortfalls, was a GOOD idea overall, too bad they didn't update and evolve it further.
SY belive me we listen... That is our main "objective" evaluation. We also measure, but I mostly measure my drivers in order to really know them well. when the speaker is made raw and fairly straight we adjust by ear. drivers do not play same frequency content the same way so when you sum then there must be a little suck-out where the drivers overlap, else we find and interpret that area being too strong. (the BBc monitor is a good example of this, while most understand the curve as a target, it was just an accident as the two driver could not zum to a straight, and thus they created an icon.what the achieved was a speaker where the rights were bigger than the wrongs, thus our psycho-acoustic capabilities are freed to interpret the music and not tied up in trying to filter the bad stuff away)
Personally I don't find active very good. Passive (serial crossover) lets the dynamic change in the drivers be reflected in the other drivers in the system. this is not possible with digital or active. i have heard good result with bi-amping where a second amplifier drives the bass section.
Scot Struer is not the center of Denmark. nor is B&O the only audio company we have in little ratner cold and winter-dark Denmark
Personally I don't find active very good. Passive (serial crossover) lets the dynamic change in the drivers be reflected in the other drivers in the system. this is not possible with digital or active. i have heard good result with bi-amping where a second amplifier drives the bass section.
Scot Struer is not the center of Denmark. nor is B&O the only audio company we have in little ratner cold and winter-dark Denmark
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You need to read the "Geddes on
waveguides thread".
Interaction of speakers and room and subjective response is discussed there very thoroughly.
waveguides thread".
Interaction of speakers and room and subjective response is discussed there very thoroughly.
PMA: the speaker is supposed to be a reverse microphone, NOT an instrument. this is the only way it can reproduce a recording taken through a microphone. But i agree this is not a very clear and well resorted/resolved case. One big issue with speakers is that the summed membrane area (dimension) vs the wavelength is not a constant, thus the speaker radiates different over the frequency band. ideal would a continuous larger cone with lower frequencies.. (and NO a paper cone gradually decoupling area is NOT that) opposite phase is also energy in the room, even if the measurement mikes and measurement mathematics does not consider it so
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No, they are not solved - not in the sense that every piece of typical gear that one purchases has all the issues resolved, and doesn't require further work. When I first achieved, quite accidentally, optimum sound I thought, "Ah-ha, this is goal, obviously other people will also have achieved this, understand it, there will a collection of knowledge relating to it" ... Haahhhh !!! In the decades since I've kept my eyes and ears wide open, to keep monitoring whether others have picked up on this - and it's pretty obvious that it occurs but rarely.
From my POV there has been close to zero movement in the decades I've been interested in audio - and in many areas it has got worse; the disease of amplifying everything has spread far and wide, and since much of the gear used is pretty crappy it makes the experience of listening to music in the commercial areas borderline tolerable, most of the time. In the home use arena, expensive, "audiophile" systems often sound absolutely terrible, and supposedly well engineered setups are dreary and tedious, have the life sucked out of them, are boring to listen to.
The real solutions have always been around, but they are nearly always ignored, overlooked, not considered important enough - but they still remain there, just waiting for the next bright spark to pick up on the clues ...
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I would rephrase that as "The more accurate the reproduction is at the surface of the speaker drivers, the more you hear only what was recorded". Subjectively, the playback room contribution retreats and becomes a minor participant in the proceedings - the mind has no trouble discarding its impact, and the recorded acoustic holds sway ...
Full symphony orchestra is not a problem also - the difficuly with this sort of music is that its complex, sound tapestry requires every element of the reproduction chain to be at its 100% best behaviour - and frequently this is not the case, meaning that the reproduction "does not work", is not convincing.
And the answer is: that "problem" means sweet FA, has zero impact, if the reproduction is good enough. The brain then gets enough information, the vital low level cues are not buggered up by low level distortion, noise modulation, interference artifacts, whatever you want to call it, and the mind is able to unravel it all, it turns the sound of the instrument into a convincing illusion, within the skull.As well, all instruments have different polar patterns, so do mikes. That's the part of audio which isn't a solved problem, so naturally, we shouldn't talk about it.
When you've experienced a system on the edge of being capable of this, and then get the last block into place, for the sound to be good enough for the illusion to blink into life - then one can start to understand what the process is. Having done this over and over again, over many years, I've sorta got a bit of a handle on this now ...
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