View attachment 14422
I am reposting this chart to illustrate why what we hear is so objective. And explain a little about the term we hear often in audio, Decibels. This chart shows the NORMAL hearing range of the male human ear based on age. As you can see at 20 years old you have pretty good hearing across the audio range. By the age of 40 years old hearing of the high frequencies above 8 kHz is 20 dB lower. A -20dB is a drop in hearing to 1/4 of what it was at 20 years old. Or to put it in the opposite direction a 20 year old hears the high frequencies 4 times as loud as a 40 year old.
The term Decibels or dB is a measuring unit that must be referenced to what is being measured, for example in power measurements a 3 dB increase is a doubling of power. A 3 dB increase of an 100 Watt audio amp is 200 watts. When dB is used in relation to human hearing a 3 dB increase in sound is barely discernable to your ears. Because dB is a non linear measurement, the math is a little funky. A doubling of your power amp (+3dB) from 300 to 600 Watts will not double what you hear, it will just be a noticeable increase. A +10dB is needed for yours ears to discern "twice as loud". In a nutshell after the age of 20 for men you lose about 1 dB per year above 8 kHz until age 40 then about 2dB a year thereafter.
What this shows is we all hear differently, this chart is for men, women suffer much lower losses with age. So women hear different from men. My wife can even hear what I am thinking at a rock concert. How can a 40 or 50 year old man judge sounds they can barely hear? I cannot tell you how the highs sound in a speaker until they are adjusted for my ears, once that is done I can then judge the entire frequency range and give an opinion of the overall balance. We as humans can only testify to how something sounds to OUR own ears. If everyone listened to music the same way with the same ears we would not have had various types of tone controls on audio equipment for over a century to compensate. The effect we are talking about can be compensated with the built in EQ. Although the adjustment is highly technical I will attempt to explain. If the music is too bright sounding to you turn the highs down......not bright enough, turn them up. And keep in mind that the source of the music you are playing may also require adjustments to your ears.
My thoughts on stats is that statistics are very overrated and extremely over used. When you can take a sample size of 625 people make that a representation of 6 billion, I don't think that works and there are thousands of reasons why it doesn't work but we dont need that have that conversation here. Yes, we all loose hearing as we get older. Some more than others depending on how well they took care of their hearing and there are probably some genetic issues there as well, but sound is not objective. It is a very personal and subjective thing. The real difference in subjective vs. objective is that objective situations can be observed independent of personal biases and experience (i.e. data), whereas subjective situations can usually only be viewed by one person, filtered through their unique lens of personal experience, taste, emotion, and bias (Websters). While you have presented data, that data does not accurately represent the total population. If we all believed statistics like the press did, Hilary would have been president (And no, I did not want her to ever be president). Tone controls have single handily destroyed music because people A. were never taught how to use them, and B. Never used them correctly. Your definition of tone controls is like you have tool box, and inside the toolbox you have a hammer and nails. Your door knob is broken, so instead of going to the store and buying a door knob to correctly fix the problem, you take that hammer out, you hammer a nail in the door almost all the way in, then hang the hammer upside down on the forks to use a a pull for the door.
There is no disagreement on your comments "what we all hear is different" that is abundantly clear. You get that from the gear people put in their car, and you are I are two glowing examples of that. Hell, even how some people are ok with the factory system and some are not. Tone controls were never designed to allow you, the consumer, to correct for your hearing. That's like that mess in the 70's when the EQ came about and everyone just set it to a smiley face by raising the highs, raising the lows, and sinking the mids. You even still see this in brand new cars when I get in to test drive and some yahoo has been in the car, and adjusted the radio by turning up the treble and bass, and turning down the mids when the factory radio is equipped. I am able to detect it every time. Why? Because the factory system was tuned for its environment to bring the system back in alignment with the acoustics of the car, and everything in the car that effects the acoustics.
So with that said, lets take the question of what DOES and DOES not sound correct? Who am I at age 49, based on your chart to say what sounds correct and doesn't? What sounds correct is the intention of the artist who recorded the music. That is the only reference you can use. Be it John Williams when he conducted for the Star Wars, or Jaws, or Indiana Jones movies, or Stevie Ray Vaughn when he recorded his interpretation of Voodoo Child. When the 8-track, album, Cassette, DCC, CD, DAT, MD was laid down on the media, that master tape had what the artist intended and over time the quality of that original recording has improved with technology. Now, while I will admit my method for getting to what sounds right is of my own concoction it has been tested in many cars against many good sets of ears and it works every time and does not require your hearing to get right, it does require an Real Time Analyzer.
But before I get into that, your chart and what your talking about are two different things and for those interested I think needs clarification. Doubling your power, gains you 3db in amplitude not frequency independently, they work together. Amplitude is measured by your ears in pressure and unless you ear drums have been blown out, you can discern the difference at age 49 between 100 watts of power behind a speaker and 200 watts of power behind a speaker for a multitude of reasons that I will discuss below. At age 49, I can come real close to even telling you what the problem frequency is while its playing. Is it guessing? I don't think so, experience more likely. Your chart explains how over time your ability to discern higher frequencies diminishes. I agree with that assessment 10000% percent. But that a person cannot tell the difference between a car horn and a train horn would be complete nonsense. An average car horn is 94 db. In the United States trains are required to play their horns at least 96db, and a maximum of 110. I don't know about you but I can not only hear that but feel that. Most people can discern the difference between clarinet and a flute or a flute and an piccolo. Lots of us old people going to classical concerts and there are a lot of frequencies being played from the orchestra. So just want to clarify.
I have said in my "How to tune a car audio system" post, that I could tune the car and be deaf and get it right. I do that with an RTA. The only subjective piece here is what I am saying is the correct acoustical curve for any given environment. There is not one perfect curve, but there is only one perfect curve for every car, house, boat, plain, concert arena, arena, etc. I come to that by making sure there are only smooth transitions from frequency to frequency in a car, and by not adding anything that was not there. It is so accurate, that it can be printed out and used over and over again in the same vehicle with the same equipment. No adjustments are necessary. That curve gets you back to what the artist originally intended for how their music should be heard. Which is what the competition scene is all about. Now, granted, back to your tone controls, there are those like yourself, you want to adjust the sound to accommodate their hearing and to each their own. Some like a lot more bass than treble(I don't know whats about), but I do find it odd that most bass heavy systems are just like the old smiley face EQ setups, all bass, all treble no mid. Some guys will even load up a pair of 15's, and tweeters in the front and call it a day. I know what causes this, but I don't want to get in to it.
So why would anyone buy an amp that makes 900 watts? 1500 watts over an amp that just has 50 x 4? As you have said based on efficiency if a speaker is 93db efficient, then theoretically I could buy a 4 watts amp. That is 1 watt by 4 channels, and power the front and rear speakers, and .5 would go to each tweeter, .5 would go to the midrange up front, and 1 watt would go to each speaker in the rear. DONE. I can help with this ill thought logic. Your 26 Watts factory system only gives you about 7 watts of clean usable power. Which based on our 1 watt by 4 channels should be enough. Right?
Well we have to take some inventory of some items to figure it out. 1 is called headroom, 1 is called noise floor, 1 is called clipping, and 1 is called distortion And one is called DB gain. I have said, listening to music is an audible experience as well as an emotional experience. You are not going to feel anything emotional at 1 watt. You can print all the graphs you want. Its not happening. Its all about headroom. Headroom is the 20db or so between the maximum volume you can play something before taking the amp into clipping. Clipping defined is Clipping is a form of waveform distortion that occurs when an amplifier is over driven and attempts to deliver an output voltage or current beyond its maximum capability. Driving an amplifier into clipping may cause it to output power in excess of its power rating(Webster). Headroom is the sweet spot of where you take the amp to its extreme before distortion comes into play. This is where the music comes to life or for that matter a system comes to life. The noise floor is the bottom limits where the music disappears and the noise of the amp is louder than than the music. Unwanted distortion is caused by a signal which is "too strong". If an audio signal level is too high for a particular component to cope with, then parts of the signal will be lost. This results in the rasping distorted sound (Websters). Most people even if they don't understand what distortion is and I say most, they get it doesn't sound good. So who gives a rats but about all of this. Anyone who cars about making their system sound as good as it can and not just getting by with hearing some background noise in their car while they drive down the road.
The amp in the factory radio having about 26 watts of total power, I said only about 7 was useful, what I mean by that is the noise floor with a zero information track on a CD, you can hear the radio way above volume 10, so as volume increases so does the system noise. Which means you are hearing the system noise, on top of your music. Then at the other end, the louder you get, you run into two problems, as volume increases, you start to reach clean portion of the amp, and start to reach the limitations of the speaker both of which increase the amount of distortion that is now audible to your ears. If people are curious that is what a noise gate is for. A noise gate watches the signal and when the signal goes to zero, the system cuts the output to remove the system noise created by the system.
You can hear system noise. It sounds like a average fan running in a quiet room. You can hear distortion. It sounds like listening to a clarinet playing but instead of it being sharp and clear, it now starts to break up. Let's take our theoretical 1 x 4 watt amp and apply this science to it. Your feeding the .5 to your tweeter. the first .2 is system noise, and back .2 is distortion. So you really are only getting .1 amp of clean signal to your speaker. So when you ask why spend all that money on a car system?
Here it is and no matter what anyone says, the science behind this cannot be disputed.
For an amp to sound its best, you need it to be played at a minimum of 75% of its rated capability and you have to do a lot to get it there. That is the sweet spot with every amp made no matter what its limitations are. All amps are not created equal, but each one has a sweet spot and it happens at 75% of its rated output. So the end goal here is the more you get the amp to perform within its rated power range the cleaner it will sound the louder you play it. And if you were not trying to play your sound system louder than a whisper, then just keep your factory system.
Someone asked a couple of days ago why I chose the amps I chose, and you have said what re-tuning?
This is all about getting the cleanest sound with the most headroom available. Being able to play it as loud as possible without clipping the amp and destroying the speakers. Clean volume never destroyed a speaker. Although putting 400 watts on a speaker that was rated at 35 watts will do it. That why a tangband speaker is a terrible choice for a car. Most everything they has a RMS rating in the 50 watts or less range. Not max, because max is only good for about 10ms. The system noise in an average car audio system with zero data can easily be 70db at half volume and you haven't even started playing music. You have used up 1/2 of the speakers playable range, and when you start cranking up the volume, now distortion starts to come into play unless you have done everything else necessary to clean up the signal.
Why would anyone care about playing their system as clean and loud as possible? Have you ever gone to a rock concert, and when you left, you felt exhausted and your ears were ringing? You felt like you had been partying since 1999. The reason is so very simple and so overlooked by so many. It is the difference between a clean sounding system and not clean sounding system. At a concert, the volume is over the top, but that is not the problem, the environment, and the distortion and the noise floor is causing that fatigue. If you were in an arena, and Van Halen was on stage, and you were the only person there except for the band and sound system, You could listen to it all day, and it would be the greatest experience of your life. but at a full blown concert the band has to overcome the noise floor, which means they have to turn up the volume to accommodate for the crowd. Then they have to tune the system to accommodate for the acoustics of the bad location with the crowd.
In a properly tuned system in a car, with 2000 watts, at full volume for 3 hours, two people, including myself sat in my vehicle, and got out with no ear fatigue, no ringing, and could walk into a coffee house and have a normal volume conversation with someone sitting across the table and have no problem hearing them. NONE. It is true and it happens with any car audio system that is setup properly and any audio system in any location setup properly.
You don't stick a turbo capable of making 1000hp on a engine only capable of making a max of 200hp.
I also like how people put that amp in their car, and then don't like that its not loud enough and then they go to that volume knob on the amp called a gain control. That is not what that is for.
So what does all of this BS mean?
It means to get a system in your car, that accurately reproduces the sound the way the artist intended(WHICH IS THE POINT) otherwise, why listen to a specific artist when you could just listen to elevator music, it requires some effort beyond just slapping 4 new speakers and sub in the car. The whole reason people say a system sounds better when they replace the factory speakers is because its louder at lower volumes, aka more efficient, and the reason the adding of a sub sounds better, is because those frequencies at a louder volume were missing from the system. Sure the 6.5" sony's play 40hertz, but its down 30db. When you add the sub, your brought the volume of those frequencies to the fore front, and now you can not only hear then but feel them. Volume does not mean better. It means louder. Replacing factory speakers with more efficient speakers does not make the system sound better, it makes it sound louder.
All of the equipment I have recommended is to that purpose of making your system sound better and I am not going to make any apologizes for that. Taking advantage of a better noise floor, louder volumes without clipping and distortion and reproducing the music as the artist intended. That means making the amp play at its rated output by sending the amp the minimum required power voltage. That means sending enough signal voltage to the amp so that the gain can be turned completely off, thus almost 100 percent removing any noise created by the amp making the amp very quiet so that I am hearing the music and not the system. Adding acoustical dampening to the car which includes rubber sheets to reduce vibrations and reduce overall interior temperatures because heat will effect the environment as well, thick closed cell foam to put a layer between the car and the Mass Loaded Vinyl sheets which lay on top of the closed cell foam to remove up to 3db of external noise, which in effect reduces outside noise by double and increase the systems ability to play louder by the same amount and selecting speakers that are capable of handing more power than what I am sending to them so that they never ever break up no matter how much volume I send it. All of which allows this system to generate as much headroom as possible without clipping and without distortion, and finally the processor which is necessary to undo all of the bs in the car that is interfering with me listening to the music the way the artist intended.
You dont need any of anything I have listed here and in any of the other post I have recommended if you just want background music in your car. But if you want to hear and feel the emotion in the music, and for it to be an experience. Listening to music in the car has been around since the 30's. THE 1930's! It is part of American Culture. You will spend $2000.00 to get 75 hp usable out of this car, and cant spend less than 800.00 to make a sound system worth listening to?
I do really appreciate your knowledge and background. I do, but this is way over your head either because you have never experienced a good sounding system in a car or you just don't care, i'm not sure, but telling these people to just buy more efficient speakers and add a sub, sure, it will sound louder than the factory system, but because you are not re-tuning the system to match the acoustics, you might as well just not do it at all. It's a waste of money. "Whatever is worth doing at all is worth doing well." - Philip Stanhope, 4th Earl of Chesterfield 22 September 1694 ā 24 March 1773. My guess the first person to say it probably was grog who came up with the round wheel, but no one was around to document it.