AC car stereo hookup

Well, you'd need a 12 volt DC power supply. It would have to be big, around 25 to 30 Amps (130W × 2 ÷ 12V = 21.7A, the extra amps are for the receiver).

I'm not sure if this is the information that you need but from what I read in your post, this is it.

Vulcan You may be right but 21 amps seems like a lot through 18-20 gage wire usually used in car stereo's. I know I've smoked some harnesses in the past so I am absolutly not an expert, but intuitivly that seems like a lot of. current

Well since you did not give a Pioneer model number (Pioneer Super Tuner III is a feature) I will have to approximate.

130W max power is (well a value used for marketing purposes and not particularly helpful). What you have is about 22W x 4 channels continuous based on Pioneers website and other stereos I have worked with (I am also assuming this is RMS from experience). So, if you want to fully drive 4 channels you will need, at a minimum, about 88W + 12W (to cover conversion losses inside the stereo) = 100W power supply with an output voltage of around 12V, giving around 8.3A. A 13.8V radio transmitter power supply may be a better (and possibly cheaper option).

I have looked at doing this before for a friend and his 1kW amplifier, but the cost of the power supply is just too high. In the end, a couple of car batteries and an inexpensive charger may be a cheaper option.

As a side note, I built a fairly inxpensive 50W RMS amplifier to power my custom built 12" earthquake ported enclosure sub. Works really well in the lounge.

Gadzuks! I've forgotten about PMPO! Peak Music Power Output is a totally devious way to fool the ordinary consumer (which I obviously am ). Having worked in a sound contracting company, everything to me was in RMS including power output.

Is that 130Watts PMPO or rms?

I remember back when I was shopping for a stereo system for my home. The sales lady led me to a unit that shouted 300W on its front panel.

I was dumbfounded! It was such a little unit and didn't look like it could handle such power. The sales lady kept talking about how I could blast the neighbor's ears with this little baby. Meanwhile I was looking in the back of the thing trying to find the AC power rating. Then, in small letters, I found in the back of the speaker box the words "50Wrms".

This is totally irresponsible advertising if you ask me.

The cd player is advertised as 45W X 4. Right now I am only concerned with powering the two yamaha outdoor speakers which are advertised at 130W max power input, but may want to add more in the future. The guys at radio shack tried to tell me that a 3 A 12V DC power supply would work, but I find it hard to believe.

I have tried to find a home theater combo unit that has an FM tuner and cd/dvd player but cant find one without purchasing the entire package (surround speakers and all). I would have thought someone would sell this.

From the Yamaha website (link below) the actual continuous RMS power (which is the value you need to design to) is, not surprisingly, a lot lower than the peak average value. 40W per speaker sounds much better. Of course it really depends on how loud you want the volume, a 12V 3A power supply will work and would work fine for average listening volumes outside for 1 or even 2 speakers (remember amplifier power and sound volume do not have a linear relationship).

http://www.yamaha.com/yec/products/productdetail.html?CNTID=200138&CTID=5003200&ATRID=1020&DETYP=ATTRIBUTE

A fun exercise would be to grab a car battery and an ammeter and actually monitor the current the system draws, this may help optimise your power supply choice. Alternatively, get a power supply 4 times bigger than the 3A one they suggest and use it to power all 4 speaker outputs.

P.S. You can get the home theater unit you want all day long on E-bay...

Get yourself a simple 10A Power supply and go to town, you'll do just fine with that. 15 Amps if you're really going to push things, but I doubt you'd pull that current if you had a dozen speakers hooked up (and the speaker resistance in this case would far outweight the importance of their rated power anyway).

We used to power those old Pioneers with an AC adaptor that had the output adjustment switch on it (I.E. 1.2, 1.5, 3, 6, 9 and 12V). That 45 Watt per channel rating is true for about 7 milliseconds when you first power the unit up and the outputs are still muted (until the power supply regulates). That unit will run between 8-11 Watts per channel if you run it wide open.

That unit is old as the hills my friend...anything with a Super Tuner III in it is a great old piece, and should run like the dickens (I wouldn't be surprised if the CD player still worked in it). I've been a Pioneer certified Mobile electronics tech and MECP certified (Level Two) installer.

Jakey Jake that is dangerous, some cheap chargers have very high off load voltages which might blow the equipment.......!

At best you need a 12 volt car battery to try and keep the voltage down.......A small 2amp charger and a good sized battery would work, but do not leave the charger on all the time, or you will be gassing the battery......a nacked light and you will have a big bang!! If you do not understand the technology, leave this version alone!!!

Buy a good, cheap (2nd hand from Ebay?) regulated power supply with a properly regulated 12 volt output, voltmeter and ammeter, with at least a 5 amp capacity......that way you will not get overvoltage....it will work fine.

no any standard car player can produce so large power for your speakers.

just think of such little space in a car!, in fact it only need 2W power enough for your enjoy programme. but some times music need more peak power, so peple mark their products at high number, and meantime, for a headroom, manufactruer will produce some more power to satify with younger requirement. so 10W, 15W, and 20W can be get. they are peak power, not average power. in an ordinary theater, 15W speaker enough for near thousands of audiences watch film.

but due to business, people like their products has more higher power up to 1000W!

dont believe ti.

so please chech out your speakers specification and then select correspondent power amplifier for your stereo player.

don't forget to impedence match your speakers. car audio usually runs 4 ohms for each speaker output and home theater speakers are usually 8 ohms. if you don't impedence match the amplifier, you can make it run hot or even blow transistors.

Not with 8 ohm speakers on a 4 ohm output! It will work just fine.

The other way round is not to be recommended though!!

I dont agree to you completely. the output of the aplifier has different ourput selection, one is OCL, or OTL out, you can unconsider the impedance and link directly. if the amplifier is consistant impedance output you have to consider the impedance match.

most of the car stereo player are the first output. you can link any impedance speaker, high or lower, no problem.

This is very, very bad advice...

No offence Dude, but almost all car audio is going to be sensitive to the impedance of the speakers it will be driving. This is the number one factor considered when sizing equipment / power requirements...Speaker count, Impedance and connection algorithm (I.E. series, parallel or a combination of the two).

As a matter of fact, most car audio is actually designed with different power ratings, depending on the speaker impedance (as it should be) and classified that way in competition. If I have a 1000W @1 Ohm Class "A" amplifier running to a pair of parallel wired 4 Ohm speakers (2 Ohm load), then I can compete at the 500W level because that is the most my Amp will be able to supply. And even if you are not running amplification equipment with impedance sensing output, the amount of current that the amp will pull is based on these numbers (E=IR...or in this case, I=E/R...Current = voltage / resistance or 12.0V / 4ohm load = 3Amp max draw per speaker).

The amp in that unit is designed to run four, 4 Ohm speakers maximum (or any combination and number of speakers equaling 4 Ohms per channel) for a max Current draw of 12 Amps, plus 15% for variation in the regulated power supply to account for 15-17V input voltage when the alternator is running. This is how the manufacturer ends up with a 15 Amp main power fuse on the unit (12.0 Amps + 15 % for a total of 13.2 Amps max).

You should never just hook any speaker up to any amplifier...even if you're not going to listen at high volume, you could overwork the mains and toast them in a very short time.

Very bad advice? No!!!, quit not!

I noticed you metioned your amplifier a A class amplifier. do you know these different classes' defference?

A class amplifier is of a transformer couple type. its resistance match type. its efficience is less than 50%, although it has a good behaviour on distortion. of cause if you dont match resistance to output, it will has more less power output! thats why I said one is resistance match type amplifier.

To improve efficience, people use AB class , B class, c class, d calss and e callss and f class and H class amlifier.

but more recent, we use B class , if no transformer output, we call it as otl, if no capacitor, we call it as ocl.

these amplifier has a very low resistance output. we can call it voltage output tupe. then you can link any resistance speaker at its output! no problem!

pls do remember their different!

now you will understand why different class amplifier has differnt efficiency and different connect way!

In our mobil phone audio output, its D class amplifier. its belong digital modify way. has more efficiency than ordinary b calss.

if anyone out there want to know more about AB, C, E, F, H etc class amplifier, tell me I can offer you more knowledge about them.

If you wnat to know more about audoi room arrangement, absorb material selection, power select etc studio knolege, I will be pleasure to take care.

If it's got an inline fuse, check the fuse size. That should give you a ballpark idea of what size power supply you will need. For a more accurate answer, you could put an ammeter in series.

Ballpark figure for a regular car stereo fuse is 15A. I sincerely doubt you will pull anywhere near that though even at full volume with 4 speakers connected.

As suggested, get a car battery and an ammeter and give it a try.

DO NOT USE A CAR BATTERY!!!! use deep cycle batteries, car batteries are designed for short bursts of high power, then the alt takes over. you will ruin a car battery so fast...

In practise, as long as the speakers have either the correct impedance or are higher, no damage will be done to either the speakers or the amp.

the only proviso isas long as the speakers are of a sufficient wattage, just in case someone screws the volume up. But this is also true of when a 4 ohm speaker is attached.......so that is nothing new......

For maximum volume output, in this case, a 4 ohm speaker would be slightly louder, that is all....

I doubt seriously if anyone could tell the difference!

generally speak, the speak has 4, 8, 16, and 32 ohm resistance. if you connect the 4 ohm speak to a fixed voltage output amlifer, you would get more power than higher ohm speak connected.

but if you connect a fixed resistance ouput amplifier, you have to connecta matched speaker, otherwise, youi will not get maximum power output.

this is their difference.

your germany has the gest speaker manufacuterr. I read many book in the old time was wroten by your germany specialists. and they are translated into chinese.

....and that is exactly what I said! Also, how often do you run at max volume? Like almost never......

No damage will be done to any part of the system as long as the loud speakers are of the same impedance or higher........that is the important part that a newcomer must understand......

(But do not forget that some manufacturers have made errors in design that might cause damage when using the correct impedance and full volume, as they thought it would not be noticed!!! Using a higher impedance will reduce the possibilty of damage at that point slightly!)

speaker damage or not depend on the output fo the amplifier.

almost of amplifier has higher power output to get a good sound quality. especially semiconduct power amplifier, they would be better to have a 4db room head. or even higher if you enjoy music at hi fi .soem of them can be 10db. becasue of our human ear feature.

so pay attation to power output, dont broke down your speaker. especially your high frequency speaker part.

Some words got lost in your message, it does not make much sense anymore.

Please remember that the original use was a car radio on a mains outlet!! This guy is not interested in HiFi, he just wants to hear music!!!!!

If he was really interested in HiFi he would be buying himself something really upmarket in a system with components etc!!!

You appear to have not read and understood what he really wants to do.....

oh, sorry for my speaking too more...

but the car stereo is belong to hi fi.

dont mind, if I make a mistake.

I think I will jump in here with a few comments. Firstly, the primary cause of speaker damage (other than accidentally putting sharp objects thru the cone) is when the amplifier driving the speaker is pushed too hard and the output starts to clip. This causes the nice sinusoidal waves to become square wave-like as the peak of the wave limits to the max available supply rail voltage. This in turn causes heating inside the coil of the speaker, resulting in letting the smell out and damage (over time). Now, the interesting thing is it is easier to accidentally damage a 1000W speaker with a 5W amplifier than a 5W speaker with a 1000W amplifier.

Also, the average stereo, be it car or home, has a volume dial on the front (nothing new there), but remember this is merely a volume control which controls the amount of amplification of the audio signal being fed into the amplifier. Just because the dial go's all the way up to (say 20) does not mean you can operate it on volume 20 and everything will be fine. If you have a large input signal, or a lot of low frequency bass (which requires more power from the amplifier) the amplifier will reach its limits long before the maximum volume control end is reached, resulting in signal distortion, clipping and potentially permanent damage to the speakers (and potentially hearing loss as well ). Always rely on your own hearing and common sense when adjusting the volume control.

On a side note, I was just in Swabish Hall for 2 weeks on training. What amazing weather, it didn't even rain. (well, until I left anyway).

fist of all, I wish you dont mind, dont angry to my words.

distortion is another thing we discuss here. it can cause spaeker damage, but its not main cause of damage, the main cause is power too higher.

the number you see on the meter ( so called UV meter) is normally indicate a signal level before power amplifier. the whole audio equipment has definite level at dfferent stages. it depend on sensitive and distortion.and popwer output.

for example, at 0 position of the uv meter, (1mW or 0.775V, or 1mv or 1V, depend on your difine) the power output is 10W, if the pointer over to red line db, the power will be more, say, a double. if the speak can afford 15W, you keep the pointer less time over the db. etc. other wise the sp;eaker will damage. leep the pointer at gree zone. or nagetive zone.

so 10w amoplifier cannt damage the 100w speaker, and 100w aplifier can easily damage 1w speaker.

the intensity of sound depend on the power ouput. no doult.

of cusae human has diffent hearing sense, just like everybody has diffent higher. but we have a hearing standard. generally, we measure a sound fireld at 1M distance at 1W ouput.

man has a different frequency response is another thing. ie, middle is sensitive than two sides, lower frequency and higher rfrequency. we can amusse it at 500-4khz as middle zone. ... we can discuss at another thread, if you are interested in it.

Audio amplification is one of those subjects that gets more and more in depth the further you take it.

So, I still stand by my comments but add that if you have a 100W amplifier and a 1W speaker, AND you decide to push the speaker cone too hard by overloading it, it will obviously be in danger of being damaged. Now this is easy to hear (mechanical noise as the cone slaps against the ends when you try to drive it past the end of its maximum travel). Distortion and its associated resistive heating (due to the associated DC current) inside the coil can be much subtler (especially at the low and high ends of the audio range). This you may not hear or notice (until the smell of winding varnish and cooked formers or lack of sound coming out of the speaker), hence much more dangerous. This is especially relevant in sub woofer amplification due to the large amounts of power being dealt with. Remember, a 1000W sub woofer is designed and rated for 1000W ac. It is not designed to run on dc. As a little experiment, get an old high-power rated 4ohm sub woofer and put a 9V lantern battery across it and see how long it takes for the coil to be destroyed (the answer is not very long at all).

After all, you expect the end users to have at least some common sense (and hearing left) to notice when they are overdriving a speaker.

I used to design and build my own amplifiers and ported speaker enclosures.

100 to 1w is only an example but some people use 100w amplifier to load a, say, 15w or 20 w speaker in practice is true.

why, its depend on HI fi, audio spectrum construct, amplifier feature etc.

not only dc produce terrible heat, but ac can produce, especially there is ac heating in speaker.(virtual value). unless you use ocl circuit and one side drive device is broken out, a dc suddently flow to speaker.

woofer speaker part needs more power than other parts, as it has more longer distance travel when works. of cause it has more heat produced than other part( in composite box) , thats why designer try to use magenetic fluid in magenetic path to descent heating as a heat sink.

the level meter or power meter keep you not to burn the speak with a good acoustic quality.

how much power amplifier did you build? whyat type circuit? and speakerbox,

we enjoy sharing with you. lets open another topic.

Well, since you asked, it all started with Sub-woofer systems. The first was a 12" Earthquake sub-woofer running in a ported and tuned 50 litre box. The amplifier was a 50W rms single channel kit, and the power supply was custom built also. I have donated this one to my parents, and makes a lovely addition to their home audio setup, except they cannot turn it up too loud or the windows vibrate.

....... well that was fun. The builders just dropped a dry powder fire extinguisher which emptied its contents all over the factory, and set the fire alarm off......

Anyway, other sub-woofer enclosures include my custom designed 25 litre sealed box with a sloping front panel which fitted flush with the rear seat of my old hatchback (this was running a JL audio 12" 500Wrms sub-woofer, with a separate 0.25F capacitor array) and few sub-woofer boxes for friends (including a twin 12" 250W reinforced sub box that was so strong you could jump up and down on it with your friends), along with all the associated car electrical wiring. I have also built a nice front speaker stereo speaker (magnetically screened) and amplifier array with a separate 10" woofer system, for the study (almost entirely out of spare parts. The 10" paper woofer is from an old electric organ).

Most of the amplifiers were kit sets, with all except the 50Wrms amp being single polarity voltage supply (i.e. single voltage rail) types.

I haven't built anything audio related recently as I just don't have the time, or anywhere to put them. But that is not really the point, half the fun was actually building them and the learning experience that came with it (and what a journey it has been).

wow, you are a good son for presenting your parents with a wonderful speakers .

however its too powerful to listen to. for an old coupler, a 5--10w amplifier enouh for a 16m2 room.

and your higher up to 500w speaker box can be used for a wild field stage of pop music. JBL is a good speaker manufactuer.

but I wonder if the 12" diameter is somewhat smaller? how much in the box?

Due to the high sensitivity (simply the efficiency of converting electrical power to sound) the power required for normal listening (when say watching TV) with the 12" sub in the ported 50 litre enclosure is about 10-15W. I don't think it has been run higher than 30-40W in the lounge (even during testing). The single port is about 120mm in diameter and during moderate bass levels you can hear the noise of the air moving in and out of the port (which was quite a surprise). The 50 litre box also looks stunning and has also made a wonderful place to stick pot-plants. It is a pity one of them leaked and some water got into the enclosure thru the port (which of course was located on the top ). Fortunately I designed, built and sealed it well so the 6-odd coats of varnish on the inside of the enclosure prevented any damage.

My JL 12" 500W speaker box is certainly loud (even with the 250W rms amplifier I am powering it with). It was expensive, but the speaker has a travel of about 3/4" which can outperform your average 15" sub woofer. I should really find the time to install it in my new car.

install your car a 500w speaker?

Can you still drive your car?

Yes, but without the capacitor array the interior lights dim with every bass note due to the high currents. I wouldn't want to leave the stereo on for an extended time with the engine off.

If you mean the town in Germany, we would spell it Schwäbisch Hall, or if your keyboard did not have the umlaut characters, you would write Schwaebisch Hall.

Also we seem to be in a new dry spell again with perfect weather, yesterday got tp 31 C here around Frankfurt am Main. (Not Frankfurt an der Oder!)

What you wrote about clipping is exactly right, we never got there before and I was trying to keep things simple for the Guy that posted the Blog.......I was of the opinion that it might be getting to be too much.....

....but if you feel its not, then you should mention the effects of too thin connecting cable to speakers......over to you again!

I think I will stay away from the wire thickness issue as the discussions then have a tendency to move into special porarized structure audio cable, cryogenic freezing to enhance audio quality thru altered crystaline structure of copper cable, and the good old gold plated single-phase house outlets for improved audio quality. <sigh>

Today's quote - "A fool and his money are soon parted".

OK accepted, but I feel that the Guy who started the Blog was just trying to get some music where no mains voltage was available......

.....and as long as his speakers are rated higher than the max output of the car radio AND are of equal impedance or higher, he will achieve exactly what he wants....

All this theory is good when designing, but when you only want to hear a moderate volume (so that the battery lasts a long time between charges for example) then it is completely overdone. A few simple rules will more than suffice!

If the blog owner sees the problem differently, I have over simplified the problem in some way for example, would he please chime in and guide us back onto the path of righteousness asap!!

The question is have we achieved what he wanted? Please let us know.

My main objective was to see if anyone knew of a cheap 12vdc power supply that would power the car stereo. I was thinking of using the power supply out of an old desktop PC since they are so readily available these days verses buying one at a hobby store or off ebay. My second thought was to just use a 12v battery, but then I would have to purchase a charger.

I thought maybe there was an easy fix to the problem.

The speakers are rated higher than the receiver and are of higher impedance so I am not concerned about that.

Some PC power supplies need a small fudge/link to actually power up. A really old PC supply from say 1986 -286 era does not need that at all, they have a switch for the mains and power up and stay on without any fixes.

I recently found some of these old supplies in a pristine unused condition for free, they are now my bench supplies!!

Even if you find one with dust and needing a new fan (the usual reason for them not working), they would do you a good turn! The fans cost very little, just make sure its a quiet one!

Look for a PC power supply with the power switch built in or built on the power supply itself.....or at least a mains switch on a short extension lead (be careful though!)...

Best of luck.