Why do audio manufacturers continually lie to us?

[Nefrodite]

4 6.5's? thats kinda small my civics rear speakers are 6x9 3 way coax definetly more surface area then 6.5 still only decent bass wise, but 6.5's = not for bass are they farting from low end distortion or high end screeching? i had to buy speakers with silk dome tweeters, all the metal ones i tried were to shrill for me ears but i'm weird

my sony amp has freq cutoff control and eq.. so that solves some probs too


as for clipping, i swear my stupid headunit blew two infinity tweeters. bzzz bzzz!! luckily it was within the 30 day return preiod

 

[StageLeft]

wbwither Yeah they're pretty good speakers. everything I've read about them told me they were the thing to buy last year so I picked them up - and in Canada they are even cheaper than in the US (after conversion of course). You see they cost $240 CAN and they cost $200-220 US if you buy them here :Q

I know I have to buy a sub - so to get the volume up I'll have to lower the bass output from the receiver as a whole right? This way I can compensate by raising out what the sub does...because as it is now if I want to go above 3 on this particular song I'd have to start actively going below neutral on bass to avoid distortion on the titans. I'll be getting a paradigm PDR 10.

nefrodite It's the low stuff that screws my car up. I'm never getting enough lows! I don't drive around with sir mixalont on either; I just love a good full bass sound to my music.

EDIT: In actual fact I think I can set the crossover point in setup on the receiver for fronts so I guess I'd make them try to ignore anything too low...

 

[bizmark]

Skoorb,

I'm not sure I really understand your question. Maybe this will answer it.

The way to set up your subwoofer really depends on your receiver.

If it's a Dolby Digital receiver, then it has the correct crossover settings and controls to handle the bass. You will set your front speakers to "Small" and tell the receiver that you have a subwoofer, which you will hook up to the RCA subwoofer output. All of the deep bass (it depends on the receiver for the exact cutoff point, but usually anything less than some point between 120Hz and 80Hz) will be sent to the sub, and none will be sent to the Titans. (well, it doesn't 'cut it off' exactly, but it rolls it off very steeply. effectively, it cuts it off.)

If it's a non-DD receiver, then it probably doesn't have adequate bass management, in which case you'll want to run the L/R speaker wire from the receiver to the speaker-level inputs on the sub. Then run the speaker-level outputs on the sub to the Titans. The sub will subtract the low frequencies from the speaker-level signal (and play them), then send the signal on to the speakers. Most subs have a crossover knob so you can set exactly the right point to mix between the sub and satellites. In this case, your receiver will think that it's just driving a normal pair of full-range speakers, but your subwoofer will be fooling it.

Once you have set up the sub, you'll probably want to keep the bass knob on your receiver to its neutral position. However, what you do with this can vary considerably, even with the same set of speakers and just moving them to a different room. Just set it to however it sounds best to you. Unless you want to buy a test-tone CD and an SPL meter, and sit there and graph things and tweak until your graph is flat as possible

Really, that's something that I think most audio people tend to forget about: the most important thing is how it sounds to YOU. We all have an idea that flatter is better, and in an absolute sense, it is. However, our ears and our brains are not absolute. if you really have a preference for deep bass, then by all means turn it up to your heart's content.

FYI many radio stations bump up the bass on their signals to make them sound "better"!

 

[Nefrodite]

ah, your not going to be happy without a sub then i'm certainly itching for a decent one. cars are lousy enviroments for speakers.. its sad you can get 200 dollars of computer speakers that have so much more bass and general sound quality then a car set that costs 2x as much hehe car audio=little bang for buck.. no thanx to the car

 

[StageLeft]

Yeah I can ramble and become quite incomprehensible. What you said about small and large is exactly what I'm talking about though. I was without my system for about 8 months so I've forgotten its features. I bought this nice system and had to move 2 months later and only got it back a week ago. Small large is exactly what I need! I am now itching to buy my new sub. Kami told me the PDR 10 costs about $370 CAN in canada and I think it costs around $350 US down here. Curses!

 

[StageLeft]

BtW this thread has fed me more usable info than about 99% of the ones i ask. Thanks for all the input guys/gals!

 

[Jejunum]

unrelated but it is




<< It's kind of like the hotdogs and buns thing. They sell hotdogs in packages of ten but buns in packages of eight. Why is that? >>



duhhh so u buy 80 hotdogs total and have a big party...then u buy beer too..mmm beer

 

[Goi]

Most of the time its much more dangerous to underpower a speaker than to overpower it, since the amp would be driven beyond linearity and will distort and/or clip, sending a signal that will damage/destroy the associated speaker, even if the speaker is rated at a power rating(RMS) much more than the amp.

You really have to look at the specs carefully, especially the amp. Is the power rating a maximum/dynamic one or a continuous/rms one? At what impedance is that power rating measured, and at what sort of THD? Also, at what frequency range is that power measured? If you don't look at ALL of these factors, you might be misled. Many lower end equipment don't rate the continuous power rating of their equipment but rather the dynamic one. Even if they do, they might rate it at 6ohm or even 4ohm impedance, rather than the standard 8ohm, to increase their power rating. Other "tricks" are qualifying their rating with a high THD(<0.1%), set the frequency of their measured rating at a single value(usually 1KHz) rather than the entire audible frequency range(20Hz-20KHz), or measure the power rating with only 1 channel driven.

So, what you come up with is a distorted picture which is very misleading. In your case, you think your receiver is 5x110W, but it could be rated at 4ohm or 6ohm, while your Paradigm Titans are 8ohm nominal impedance speakers. Because of this, your receiver might actually only be 5x60, and driving them to maximum will cause clipping/distortion which will ultimately destroy your speakers.

 

[Jerboy]

<< I have yet to come upon an audio system in which the speakers were rated along with the power source and the power source was unable to destroy the speakers. For instance my home theater receiver is 5 X 110 and my paradigm titans are rated at I think 100 watts each. This thing could blow them without even trying if I wanted to. In my car 17 X 4 RMS on my head unit rating is easily able to distort my 4 X 40 RMS speakers.



<<
It seems to me that for mose audio equipment if you want it so that you can turn the volume on full, or near enough, - and yes this is speaker distortion not distortion from the source >>



Not to be an ass, but how do you know?

Do you know, because source distortion did not register on oscilloscope when you fed the amp with reference sinusoidal signal and cranked the volume up until distortion could be heard?


- you'd need speakers rated several times more powerful than the amplifier itself. Why is this? >>



Actually, I believe you need an amplifier with considerably higher power handling capability than your speakers. You can blow out a speaker with an amplifier rated less than speaker wattage, because right when your amp max out, it's output is clipped and sends DC component into speaker. DC component burns out your speaker voice coil.

 

[blahblah99]

The setup in my car is two 4" midranges in the front, 1" tweeters in the front, and two 4" coax in the rear. They are all infinities powered by a precision power 4x50RMS amp. They can go LOUD because I have an active crossover before the amp that re-routes the signals so that the 4" only get frequencies above my set point (which is at 120Hz, -6dB/oct). The tweeters have its own passive crossover network. I also have two 10" subs that get low frequencies, powered by another precision power 4x50 amp in bridged mode. With this setup, my speakers can go loud enough for a block party and my 4" speakers are only rated at a MAXIMUM of around 60W.

My point? If you design your audio system carefully and adjust it so that each speakers get signal within the range they were designed for, you will be able to get not only clearer sound, but also be able to push them near their rated RMS power. Of course, you will never get what was advertised, but you may get up to 70% or even 80% of the rated power.


And about getting an amplfiier that's rated MORE than what your speakers can handle - Just think of it as a 600hp car. The horses are there, but your not always going to be using it.

Some specs that you see advertised on amplifiers and speakers:

Peak power - this is how much instantaneous power the speaker can handle for a limited time.
RMS power - this is how much power the speaker can handle over long periods of time.
THD - Total harmonic distortion: the lower the better... This is the measure of distortion in a signal, usually a 1khz sine wave, and its harmonics up to the 9th.
Freq response - The frequency response of the amp or speaker. Doesn't necessarily mean that it can't operate outside this range. It just means that provides the same gains and phase across the frequency range give in this figure. Anything outside this range will usually have a lower gain and huge phase shifts.
Impedance - Car speakers are usually 4 Ohms while home theather and computer speakers are 8 or 16 ohms. Why different impedance? I have no clue, maybe it is a marketing scheme so people can't plop home speakers into their cars and vice versa. Never stick a lower impedance speaker into an amp that requires a higher impedance load or your going to end up replaciing a lot of transistors.
Bridged Mode - is coupling two channels of the amp to provide a single channel output.

When choosing my amps, I like to pick low THD amps that have a wide freq. response (10Hz, 20hz to 22khz) and the ability to drive speakers down to 1 ohm.
When choosing my speakers, I just do a little research on the internet and GO OUT AND LISTEN to them.

 

[Pacfanweb]

<<RMS power - this is how much power the speaker can handle over long periods of time.>>

That's one of the biggest lies you see. I've seen cheesy amps and speakers that are rated at 300 watts rms, and you know good and well they'd be lucky to do 10 watts on a regular basis.

You really only get this with the off-brand crap.

 

[Goi]

pacfanweb, RMS power isn't a pack of lies, its the way manufacturer's are using it that is. Read my previous post.

 

[C'DaleRider]

Actually, there is a very strict set of guidelines the gov't has for measuring RMS ratings in amplifiers. (This vaires by gov't agency...the Euros and Japanese use somewhat different methods compared to the US.)

Now this is off the top of my head, but the amp has to be turned on for an hour or so at half-volume to precondition it, then the testing is done. RMS can be measured at whatever percentage distortion the manufacturer wants. Those cheapie amps sometimes have outrageous wattage claims made, but on investigation, one will notice the distortion at the listed wattage output is sometimes at 10% distortion....just enough to blow your tweeters all to hell.

One must remember that the woofers draw the most power trying to produce bass notes while comparitively the tweeters draw very little power. The problem lies in trying to get too much bass output from your speakers, driving them too hard, causing the amp to clip, and the tweets are damaged from being overdriven by a clipped waveform and unregulated power output. Essentially, when the amp clips, the "restraings" on the power output at peak from the amp disappears and the amp will just shoot out much greater than rated power.........not a clean signal, but powerful. The woofers are usually strong enough to absorb this momentary spike, but the tweeters are much more delicate and hence blwo much easier.

Impedance is the resistance to electrical flow. Impedance ratings on speakers are not a marketing gimmick, but instead are usually a measure of their effeciency. Low impedance speakers usually requier fewer watts to produce the same decibel levels as higher impedance speakers. The impedance an amp/receiver expects to see is what the switch is for on the back of your amp. Setting the switch for 8 ohms and connecting to 4 ohm speakers will let the amp overdrive itself and qutie possibly damage the circuitry inside. Please note, the better amps are quite able to handle a wide range of impedances without havign to have a switch to take care of it. Amps like Macintosh and Adcom do not use impedance switches.....they are usually able to handle 2-16 ohm loads. Department store amps, like Sony, et al, can have trouble with low impedance, hence the switch to dorta "preload" the amp with low impedance speakers.

 

[Capn]

Speaker Impedance, generally looks something like this


-----------------------------------------------------------------------------------------
-----------------------------------------------------------------------------------------
-------------**--------------------------------------------------------------------**--
------------*--*--------------------------------------------------------------***-----
----------*-----*--------------------------------------------------*******----------
--------*--------*--------------------------------**********----------------------
-----**-----------*-----------************--------------------------------------
***-----------------******----------------------------------------------------------
-----------------------------------------------------------------------------------------

Where the verticle axis is impedance, and the x-axis is frequency. The peak is the resonant frequency of the speaker IIRC. The speaker manufacturer takes this and calls it something like 8 ohms nominal, where the actual impedance at any particle frequency could actually be far above or below this.

 

[tcsenter]

I had a 1990 Cavalier into which I put a Kenwood cassette head unit, a Kenwood 150w 2 channel amp (75x2), 2 Alpine 6x9" rear deck speakers and 2 Pioneer 3 1/2" front dash speakers. All models were on the lower-end of each company's product line. I was really just buying the least expensive but reasonable quality components I could get.

That car rocked like I had spent two or three times what I actually did. The 6x9's hit hard and undistorted all the way up to eight or nine, depending upon the music, harder than I ever thought 6x9 speakers were capable of. Nobody could believe all I had were 6x9's powered by one 150w 2-channel amp.

At first I thought the Alpines were just that good and I got lucky in selecting them, or maybe the Kenwood amp was that good, but after talking with some audiophiles, and doing a bit of reading, the more likely reason that my system seemed unusually powerful and responsive is that the interior of my Cavalier and the volume of my trunk space fell within what would be an optimal range for the design and specs of my 6x9's, if one were to calculate an optimal enclosure and listening area precisely for those speakers.

It wasn't that the Alpines were that great, although they were good speakers, if you put any decent quality speaker into an optimal enclosure and your listening area has optimal properties, it will sound far better than a much larger and higher quality speaker in a poor enclosure. I did notice that if the properties of interior pressure changed even a little, such as having a window rolled down an inch, it diminished the responsiveness of my speakers and they would slighty distort at the same volume. But, when the windows were rolled up, WOW.

Being that most car audio systems are very poorly matched to their environment, it is really not all that hard to believe that a small system could out-perform systems costing two and three times as much.

Unfortunately, I've been unable to reproduce this 'matching' of components with their environments in any other vehicle I've owned. I've since owned a few cars in which I installed good aftermarket sound systems costing much more than what I spent on that Cavalier, but NONE sound as good as that Cavalier did. Damnit!

 

[ttn1]

I agree with the last post regarding enclosures. Many of these rating may have something to do with optimal enclosures as well. Although I may be wrong. If a speaker is set on the floor and connected to the best amp in the world, I seriously doubt if it would sound that great. It would also probably fail before meeting it's spec power rating.

Enclosures are very important in car audio. It may be hard to believe, but your car door or trunk is probably not the optimal enclosure for your speakers.

That being said, most of the power ratings are ballpark figures at best. This has been repeated over and over in this thread. All of the ratings WILL vary with frequency and many other factors. Saying that manufacturers lie is not necessarily true. They just tell you what you want to here. They give you the optimal power rating at the optimal frequency with the perfect environment.

I guess I lucked out when I built my car stereo. I bought reasonably good speakers. I used 2 - 8" subs, 2 - 6" woofers in the rear, 2 - 5 1/4" midrange in the doors and a set of tweeters in the dash. I bought 3 - reasonalby respectable 2x50W RMS amps to drive the system. These amps are well below the ratings on the speakers. I did use proper filters to shape the frequencies going to each speaker though. What exactly is the point of sending a 10 Hz signal to a 5 1/4" speaker or a tweeter for that matter. With these low powered amps, the system can still get loud enough to not want to be in the car. The volume can be maxed and the sound has barely noticeable distortion. So I guess what I'm trying to say is that a system can be underpowered and still run at full volume with good sound.

That being said, I have never trusted car tuner amplifiers. I always use seperate amplifiers fed with the line out from the stereo.

 

[StageLeft]

<< Setting the switch for 8 ohms and connecting to 4 ohm speakers will let the amp overdrive itself and qutie possibly damage the circuitry inside. Please note, the better amps are quite able to handle a wide range of impedances without havign to have a switch to take care of it. Amps like Macintosh and Adcom do not use impedance switches.....they are usually able to handle 2-16 ohm loads. Department store amps, like Sony, et al, can have trouble with low impedance, hence the switch to dorta "preload" the amp with low impedance speakers.
>>

Several years ago I had an old receiver in my house I'd been using. On a whim I decided to take some car subs I had (when I was 16 around 8 years ago I had a brief interest in car audio until my total lack of cash shut that interest down). I hooked them up to the receiver and they sounded good! Then they blew the receiver. I guess this is why

 

[ElFenix]

lots of good info here, keep it up

 

[glen]

For those of you playing along at home,
Clipping does not magically increase amplifier power and blow speakers.
This is probably the biggest "Urban/Audio Legend" I know of.

 

[bizmark]

<< For those of you playing along at home,
Clipping does not magically increase amplifier power and blow speakers.
This is probably the biggest "Urban/Audio Legend" I know of. >>



Has anyone in this thread said anything to that extent?

 

[glen]

<< Has anyone in this thread said anything to that extent? >>


No.
In fact, many have said otherwise, hence the importance of setting the facts straight.

 

[bizmark]

Ugh.. ambiguity. I'm not sure if you knew what I meant, and I'm not sure if I know what you meant.

What I meant was, has anybody said that clipping makes an amp magically have more power and blow the speakers?

 

[Nefrodite]

For those of you playing along at home,
Clipping does not magically increase amplifier power and blow speakers.
This is probably the biggest "Urban/Audio Legend" I know of.

sorry, its just my impression that from the posts in this thread it wasn't an issue

 

[Linux23]

great read!