okay, i'm sure i'm not the first to think about this, but i wanted to find out what would be necessary to turn my old cd/mp3 head unit and 4 perfect-condition factory speakers into a tabletop system

i have an aiwa mp3 player from my car that seems to work fine (it was starting to get a little sketchy when playing discs on bumpy roads, but i'm sure a mustang suspension didn't help the situation), but i like the display a lot (large lettering, pretty colors) and thought it would look pretty good sitting on my desk

i have the four original factory speakers that are in perfect condition (i left the two memphis pro references and 3-way pioneers in the car for $100) and i remember that they actually sounded pretty good before i swapped them out for a slightly more high-powered system

anywho, i know that subs have to have a more acoustically-specific box in order to work correctly (something about reverb?), but that speakers can stand free (like they do in cars)...so if i want to turn them into tabletop speakers, do i need a specially-designed box? if so, what do they need to be made of? what dimensions (the speakers are 5x7)?

and before y'all start telling me to google it, i found SOME resources, but they didn't really answer my question (i'm usually pretty good at googling, but i don't too much about the topic to put in the right phrases)

thanks for the help

9/17/2005 11:10:37 AM

you'll need to get a 12 VDC power source that can handle your HU. They aren't cheap.

9/17/2005 1:15:38 PM

you can't just join the wires from the back of the head unit to a wall plug adapter (you know, the 2 or 3-prong things)?

9/17/2005 2:27:16 PM

car stereo runs on 12V DC. wall power is 120V AC. you'll need a AC to DC power supply that outputs 12V at about 10 amps to run the head unit. if you want to add subs to this later on, you're gonna need a really hefty power supply that can do about 30 amps.

i would suggest building small boxes for the speakers. they don't have to be anything special or specific, but free air they will not have any bass at all. in simple terms, the sound waves from the back of the speaker and the sound waves from the front of the speaker cancel each other out and you get no sound. when you put a speaker in a box, it keeps the sound waves from behind the speaker contained in the box and you can hear the sound waves from the front of the speaker.

Having boxes will also make the speakers easy to place and handle as they will no long be round and you can set them facing you rather than the ceiling.

9/17/2005 3:10:26 PM

such as a 120w power supply for a laptop (the external cord and brick setup is what i'm talking about)? wouldn't that do it?

9/17/2005 4:13:22 PM

my dell power brick puts out 4.62A at 19.5V so that wouldn't work
each power adapter is different. they are marked for their inputs and outputs.

you want the output to be 12-14V and 10+amps

9/17/2005 5:19:58 PM

Quote :

"you'll need a AC to DC power supply that outputs 12V at about 10 amps to run the head unit. if you want to add subs to this later on, you're gonna need a really hefty power supply that can do about 30 amps."

well, that depends on how much power his amp puts out. i used to have a head unit and a 50x2 amp pushing a 10 and 2 6x9s in my room years ago. all i had was a radio shack 10a power converter. worked fine and actually sounded pretty good.

9/17/2005 5:36:57 PM

don't atx standard computer power supplies have a line that runs at 12v@10a to power the mobo or something? wouldn't that work?

*as i look them up, they run anywhere from 12v@10a to 12v@34a...so would that do it?

[Edited on September 17, 2005 at 6:41 PM. Reason : *]

9/17/2005 6:28:55 PM

it would *probably* work.

9/17/2005 7:15:18 PM

As long as you don't turn the volume up loud it will "work". You'll also notice on bass notes that the HU lights will dim, voltage will probably drop below 12 (could harm the unit, esp if you turn it up). Also keep in mind power rating and peak power. A 120W laptop power adapter running at 12V will probably only handle 10A in rush...

[Edited on September 17, 2005 at 11:48 PM. Reason : 14V would be better than 12V as you would not need as much current]

9/17/2005 11:46:48 PM

I dunno how well an ATX power supply would work for powering an audio amplifier... they are switched mode, and not at all optimized for audio applications (generally optimized for cost )... it's fairly likely that such a noisy (electrically) power source would result in, well, noisy audio reproduction. I'm also not sure that they are fast enough to handle short, intense bass notes. You could solve both problems, though, by putting a big, fat capacitor (or several) between the PSU and the amp.

9/18/2005 12:46:01 AM

so...if i laptop ps and a desktop ps aren't realistic options, what am i looking at as an affordable, usable solution? can anyone send me a link to the sort of power coverter/supply i would need?

9/18/2005 4:39:26 PM

a decent computer psu should run the hu just fine, the most powerful hus (alpine v-drives) are around 26w rms x4=104 watts. that means u should get a psu capable of around 15amps on the 12v+ line, as for the speakers i would throw them in some kind of enclosure . overall problay more work and $ than it's worth. i'd just sell the cd palyer and get a cheap mini-system

9/18/2005 8:17:25 PM

Quote :

"I dunno how well an ATX power supply would work for powering an audio amplifier... they are switched mode, and not at all optimized for audio applications (generally optimized for cost )... it's fairly likely that such a noisy (electrically) power source would result in, well, noisy audio reproduction. I'm also not sure that they are fast enough to handle short, intense bass notes. "

Look, at least when Noen is giving advice he generally knows what he is talking about, even if he does have to morph it to fit his agenda. You on the other hand, are talking out of your ass.

A PSU supply has to meet the ATX spec which is 100mV ripple on the 12V line, 10%. Keep in mind this is at full power. This 12v line is inevitably going to be switched into a torroid anyway to get up to the ~30v or so needed to power the speakers properly which is going to swap any noise generated by an ATX supply. You think the supply in a car is less noisy than one coming out of a PSU? Check your head man.

Quote :

"You could solve both problems, though, by putting a big, fat capacitor (or several) between the PSU and the amp."

You mean, in addition to the ones already sitting on the output in the PSU, AND the ones on the input AND output in the amp itself?

Regardless, he is powering a HU, not a dedicated amp, and even though I am a fan of Alpine and think they are the most realistically rated HUs out there, they don't do 26W RMS on all four channels at the same time.

Even if they did, this kid isn't going to have all four speakers 5 ft from his head and blasting them at full power for any appreciable amount of time. THEY ARE THE FACTORY SPEAKERS OUT OF HIS CAR FOR CHRIST'S SAKE. It's reasonable to expect at most he will be doing 15-20W (I'm being generous) at any one time and even then his ears won't last long. And, and even if he did won't to blast them at these levels, those factors speaks aren't going to live long if he does so.

So, with all the necessary information in mind, a solid PSU doing 120W on the 12V line will more than likely be plenty for this setup. The worst that happens is you pull too much power and the supply shuts down.

9/19/2005 1:16:40 AM

uh

9/19/2005 4:45:38 AM

speaking out of one's ass ... "26W RMS" per channel vs your asstimate of "30V to power the speakers" = 112.5W per channel w/ 8ohm speakers and increasingly more fantastic as impedance decreases... that'd be more like 14Vrms to power the speakers properly... unless you're acknowledging here the significance of peaks in audio reproduction that you ignore everywhere else?

a little nitpicking... PSU supply? that's a Power Supply Unit supply then? might want to familiarize yourself with an acronym's meaning before spitting it with intent

how to lose a debate... ignore the point about peaks, construe the capacitor remark as solely relating to the noise level, and then imply a 120W -max- 12V supply will be sufficient to power a 104W RMS amplifier... I suppose the head unit draws no power for anything other than audio amplification, particularly not the spindle motor or the DSP for mp3 playback, the amplifier's capacitance you're so quick to point out certainly wouldn't be enough to trip the shut down of the PSU as soon as you turn the motherfuck on, that he will be filtering any and all bass... how does it go... you might need to get your head checked?

finally, note a few key words in my post: dunno, not sure fairly likely

if you're going to call me out for pulling a Noen, try not to pull one yourself in the process... then maybe try not to trip over the fact that I'm ALREADY indicating my own uncertainty regarding the subject in your haste to talk some shit.

OH, AND ONE MORE THING, your out-of-ass comment about car power being noisier than ATX power

A. on battery, you look like a proper fucking idiot making this statement.
B. on alternator, it's exactly the same thing, an AC source full-wave rectified. and assuming you aren't flicking your brights on and off, the ripple is pretty fucking low, easily within your 100mV ATX spec that I'd bet your bald scalp 90% of generic ATX supplies don't even joke about hitting. the ones I've seen tested can't even bring their 12v rail's nominal voltage within .5v most of the time, nevermind ripple.

[Edited on September 19, 2005 at 5:59 AM. Reason : edit]

9/19/2005 5:43:47 AM

Alright,

I'll give you the point about the 30V because in my head I was mixing HU and power amplifier (it was late)...
and while we are nitpicking, these power amplifier thoughts crept into my head thanks to this comment of yours

Quote :

"I dunno how well an ATX power supply would work for powering an audio amplifier"

So you have near zero room to 'complain' about perhaps confusing terminology or specifications I may have used.

Nonetheless, that comment had ZILCH to do with power output as you are trying to use it and was only in regards to the idea that the output of the PSU has necessary capacity and the input to the amp (or the HU in this case) will also have its own filtering.

Quote :

"how to lose a debate... "

Quote :

"ignore the point about peaks"

You are overstating them and it has zero impact to the bottom line in this instance.

Quote :

"construe the capacitor remark as solely relating to the noise level"

You must have missed this comment

Quote :

"You mean, in addition to the ones already sitting on the output in the PSU, AND the ones on the input AND output in the amp itself?"

Quote :

"I suppose the head unit draws no power for anything other than audio amplification, particularly not the spindle motor or the DSP for mp3 playback"

A few watts maybe. Probably much less than the total converted to heat in the inefficiency of the amplifier section, you tried to play smarty art and left the most obvious one off.

Quote :

"the amplifier's capacitance you're so quick to point out certainly wouldn't be enough to trip the shut down of the PSU as soon as you turn the motherfuck on, that he will be filtering any and all bass... how does it go... you might need to get your head checked?"

I don't have a fucking clue what you are talking about here. It's simple, if he tries to pull more juice out of the supply than it wants to deliver, it will shutdown. What kind of shit you are trying to make up, I don't know.

Quote :

"A. on battery, you look like a proper fucking idiot making this statement."

I never limited my comment as such.

Quote :

"on alternator, it's exactly the same thing, an AC source full-wave rectified. and assuming you aren't flicking your brights on and off, the ripple is pretty fucking low"

Hey, I guess the the coils lighting your spark plugs off don't generate any back EMF, or any electrics in the AC system, not to mention heater fans themselves sitting hear a HU, nor are you running a long wire (of maybe not sufficient size) back to power the amp (or HU even), or the maybe not great ground connection to the chassis, or any of another ton of places where noise can try to creep into an audio system in a car.

What were you saying about misconstrue?

Quote :

"I'd bet your bald scalp 90% of generic ATX supplies don't even joke about hitting. the ones I've seen tested can't even bring their 12v rail's nominal voltage within .5v most of the time, nevermind ripple."

Trite personal attacks aside, you don't have a clue about the ATX spec because a 5% tolerance is also built into the 12V line meaning down to 11.4V which you can bet my bald ass head that nearly 100% of them will make.


Since I have already wasted enough time, lets analyze what has happened here, just like all other threads you shit up.

1. Someone asked question.
2. You gave some pretty lame advice and acted like an authority.
3. Someone else debunks you giving additional, more than likely unneded, information along the way to establish credibility, of which the crucial information is all that is really needed anyway, ie:

Quote :

"So, with all the necessary information in mind, a solid PSU doing 120W on the 12V line will more than likely be plenty for this setup. The worst that happens is you pull too much power and the supply shuts down."

4. You spend 1 hr looking at the argument and formulating an attack
5. Then pick out the most obscure shit, craft false representations of what was stated, and then use this as a basis for what ultimately to a third party looks like general trolling and douche baggery.
6. And inevitably ignoring the bottom line simple advice giving that was needed in the first place.

You're really annoying. I'll be amused to see what you come up with next.

[Edited on September 19, 2005 at 10:46 AM. Reason : x]

9/19/2005 10:41:53 AM

are you fucking serious

9/19/2005 10:44:02 AM

Dude, just go back to chit chat, talk comics, attack noobs, and do what you do best

that is

be insignificant.

9/19/2005 10:47:14 AM

http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&product%5Fid=22-508

9/19/2005 11:05:05 AM

ahahaha


that back emf comment had me rolling.

someone needs to start reading electricity.

9/19/2005 11:12:55 AM

Other than trolling, what the hell are you talking about?

If you are going to poke your fat metaphorical face into the thread, how about you man up and come with whatever intelligence you are attempting to profess you might have.

Because as it stands, you don't

A) Have the foggiest fuck what back emf is
B) How it gets created in a coil
C) Anything else that we are talking about here.

You are the last person that needs to be in this thread you scum bag.

9/19/2005 11:53:05 AM

oh are you using "man up" now too

let me add that

9/19/2005 11:53:26 AM

actually, I think what happened was more like:

1. Someone asked a question
2. Someone suggests a solution that I have PERSONALLY CONSIDERED BEFORE
3. I comment in a very un-authoritative tone, stating CLEARLY several times that I did not know, was uncertain... at my most assuming point in my post, I merely implied it was PROBABLE that it would not deliver the desired results.
4. ?? You search my recent posts for something to jerk yourself to, persumably, unless you'd like to explain how you come into the thread several days later (when there's no joking about you having a life) only to troll my post.
5. I retort
6. You dig your head further into Noen's ass and initiate as many tangents as possible to cover your tail

I'd think you'd have figured out that I didn't care enough to Google for the ATX spec when you brandished it like some snotty Asian kid shitting his pants in excitement while waving his graded final above his head, and I responded with disdain. I'd comment again on the lack of interest in following through with someone elses research illustrated by the uncertainty of my first post, HOWEVER, you very clearly missed that detail then, when I attempted to bring it to your attention rather explicitly in my retort, and look here I am pissing in that high wind a third time.

I didn't bring the efficiency into it because I felt it was trivial. Thank you for bringing this debate through all the rigors of a high school physical science class, on your journey to bring it to the level of a bad Springer episode.

9/19/2005 11:53:39 AM

Quote :

"as it stands, you don't A) Have the foggiest fuck what back emf is B) How it gets created in a coil C) Anything else that we are talking about here."

yea I am sure backemf from a fucking engine starter really fucks up the battery output.

[Edited on September 19, 2005 at 12:02 PM. Reason : .]

9/19/2005 12:02:28 PM

Wow

You try harder than anyone else in Tech Talk and elsewhere to come off as some technical beacon, and upon getting, for the most part, owned pretty hard in this thread, you retreat into some

"I was saying maybe, and I am not sure, and it could be possible" rhetoric?

If that isn't one of the pussiest cop outs this site has seen in awhile, I dunno what is?

Edit:

Ignition coil != starter

GET THE FUCK OUT OF THE THREAD YOU IMBECILE.


[Edited on September 19, 2005 at 12:20 PM. Reason : x]

9/19/2005 12:19:41 PM

wow

you douche

All ignition coils have terminals connected to a FUCKING RELAY

that back emf doesn't even reach your ignition key/battery


NOW GTFO OF THIS THREAD

9/19/2005 12:37:40 PM

LOOK

YOU DUMB PEICE OF INDIAN COCK SUCKING SHIT BASTARD

I'M NOT TALKING ONE GOD DAMNED THING ABOUT

THE KEY

OR

THE STARTER MOTOR

SHUT

THE FUCK

UP

PLEASE FOR THE LOVE OF GOD

9/19/2005 12:43:55 PM

Quote :

"that back emf doesn't even reach your ignition key/battery"

Please GTFO now

9/19/2005 12:46:04 PM

Quote :

"LOOK YOU DUMB PEICE OF INDIAN COCK SUCKING SHIT BASTARD I'M NOT TALKING ONE GOD DAMNED THING ABOUT THE KEY OR THE STARTER MOTOR SHUT THE FUCK UP PLEASE FOR THE LOVE OF GOD"

YOU AREN'T EVEN IN THE CORRECT CHAPTER YET

YOU DON'T EVEN HAVE A CLUE WHAT I AM TALKING ABOUT AND YOU ARE ARGUING SOME SHIT THAT I AM NOT EVEN CONTENDING OR CONCERNED WITH

FOR FUCK'S SAKE KILL YOURSELF FAST

DO IT NOW

9/19/2005 12:54:00 PM

Then what're you talking about?


The "backemf" jumping over from the ignition coils to the head unit?

9/19/2005 12:55:18 PM

You are inconsequential to me.

Go run along and create a thread about girls you aren't getting any time soon.

9/19/2005 1:06:09 PM

omg you pwned me

Guess the "backemf" really does jump from place to place in a car.

9/19/2005 1:06:52 PM

No

I think you owned yourself.

Again.

9/19/2005 1:10:28 PM

Quote :

"Guess the "backemf" really does jump from place to place in a car."

9/19/2005 1:10:53 PM

I have a 400w ATX power supply that I bought ONLY to run car stuff in my house. It works great, no problems. only thing to watch for is that 400w is total peak... as mentioned already the 12v line varies in power as it is only to run general stuff while the high power chips run on the lower voltages. it does 11A on 12v which is 132w...

but, Cost/functionality/cool factor probably isn't worth the money on JUST factory speakers

Sell the CD player to me for $20...

http://3btech.net/ch550wadufan.html

12v 30A for $17... yellow wires are 12v... black wires are gnd
(although the power numbers add up to 650w... dunno what to believe on a shitty PSU...)


[Edited on September 20, 2005 at 3:23 PM. Reason : power numbers don't add up... oh well]

9/20/2005 3:16:15 PM

Dude. A ghetto power supply, factory speakers, and an Aiwa CD player? Put the CD Player in the classifieds (or eBay) and use the money to buy a boombox from BestBuy.

9/20/2005 3:29:41 PM

Quote :

"You try harder than anyone else in Tech Talk and elsewhere to come off as some technical beacon"

I don't really "try", seeing as nearly all of my posts are generally a few lines and off the top of my head. However, someone in the thread habitually writes page-long essays, probably ought to be including a bibliography with the essays on account of the number of references, and has gone so far as to actually proclaim himself the authority on at least one topic. Who's trying to impress, again?

btw... admitting ignorance is not a "pussy cop-out", if you're trying to help someone solve a problem. I suppose it might be a pussy cop-out if you're trying to impress people, however.

[Edited on September 20, 2005 at 4:29 PM. Reason : *]

9/20/2005 4:26:42 PM

Oh the old "essay" dis again, huh?

Your creativity is about as good as your Noen attacks.

9/20/2005 4:51:55 PM

Dude

Baldy


you failed this thread.


GTFO while the sun's shining.

9/20/2005 4:52:40 PM

BACK to the question at hand.... you could always just hardwire the HU to a car battery and set up a trickle charger to keep the battery charged. That is, if you want a car battery hanging around..

9/20/2005 7:05:45 PM

Pretty sure I won the thread if we are keeping score.

9/20/2005 7:40:44 PM

hahahhahahahahahahahha


back emf

9/20/2005 7:42:14 PM

^^^ my thoughts exactly, or a cheap car battery charger capable of 10 amps, with a motorcycle battery as a capacitor to control surges

9/20/2005 7:51:34 PM

You can't even explain back emf.

Evidenced by you having not even attempted it yet.

9/20/2005 7:53:24 PM

hahahahhahahahahahhahah

9/20/2005 7:56:02 PM

why does everyone knock aiwa? i never really had any problems with it, the car sounded great with the speakers i had, and just look at it!



3 years ago when the average car mp3 player cost $400, i got it for $200...i LIKE it!

and i don't know what y'all's factory speakers were like, but mine are actually decent...not as nice as the ones i left in the car after i sold it, but they're just as good as a mid-priced boombox

besides, i like making things...it's fun

thanks for everyone's help...if you have any more suggestions, please post them...not that you really care, but i'll probably post what i do if it works

9/20/2005 9:51:27 PM

Your refusal to explain it pretty much means I win. And if you post hahahah I'll copy and paste this post.

9/20/2005 11:04:35 PM

can you tell me how exactly your "back emf" creates ripples in a fucking head unit power input?

9/20/2005 11:38:07 PM

speaking of cop-outs... the old 'the old "essay" dis' cop-out again? I'm pretty sure the length and obviously prepared/researched nature of your posts is PRETTY FUCKING RELEVANT to the argument that I made, regardless of whether or not you have felt like responding to it in the past, or feel like it now.

finally, as much as I wanted to avoid getting involved in another one of your pissing contests, the alternator is the primary source of electrical noise in the car, in the neighborhood of 100-200 mV peak-to-peak. No other source of noise in the circuit is on that order of magnitude, don't make me post 'scope pics so help me God because I have seen them. You may stop jerking your back emf.

9/21/2005 2:15:54 AM