# Creating a test bench



## Phreaxer

What is really needed to create a small test bench/garage system? I worked at a place years ago that we had a box that we plugged into the wall and installed a deck and speakers into and were able to test decks, speakers and just generally have music in the install bay. I'm looking to recreate something like this for my garage, but don't have a clue. I'm guessing it wouldn't be as simple as using one of these: power adapter / converter AC 100V-240V to DC 12V 1000mA | eBay 
And if that link doesn't confirm it, I'm looking to do this on the cheap if at all possible.  hehe


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## 96jimmyslt

Computer power supply.

Get an 80+ gold if you care about electricity savings.

Determine how many amps you will need on the 12v+ rail though.

If it's just head units, then most likely 10 amps (my double din has a 10 amp fuse)

I just recently bought an NZXT 650 w 80+ gold power supply for my computer for $100.

The 12v+ rail on it is 54 amps.

But I'm sure you can just use any old power supply you find on craigslist for $10 or so

I have an old 500w ultra v-series power supply with 120mm fan I upgraded from if you are looking for a power supply for this.

I also modded a head unit into my last computer to test CD's so I didn't have to walk out to the car to test them.

Powered on, even played music from one speaker just fine and played games all on the same power supply.

You can even get away with a subwoofer on it, if the sub amp is under the max wattage for the 12v+ rail.

In this case, my nzxt psu is 648 watts and 54 amps on the 12v+

I am not sure if using a power adapter would be better or worse for this or not.




Also, that link claims 1000mA which is 1amp...seems like it would not power anything that uses more than 1 amp...


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## Nismo

The big problem with small power supplies (the Radio Shack 13.8v unit I purchased included) is the lack of power storage. They may put out a fair amount of amperage, but the ones I've used have had some serious issues with input surge current causing the units to shut off. It may take a cap/battery of some kind to stabilize the draw and prevent shutoff.

Eric


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## 96jimmyslt

Nismo said:


> The big problem with small power supplies (the Radio Shack 13.8v unit I purchased included) is the lack of power storage. They may put out a fair amount of amperage, but the ones I've used have had some serious issues with input surge current causing the units to shut off. It may take a cap/battery of some kind to stabilize the draw and prevent shutoff.
> 
> Eric


Or just buy a computer power supply and be done with it


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## 96jimmyslt

out of curiosity I will test my OLD ultra v series 500w power supply on my amps and see how they do.

the power supply has thermal over load protection, in rush current protection and short circuit protection.

I will post the results or maybe even take a video in a few hours


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## red line auto

I just happened on this site when surffing the web for informational site for car audio. i run a speed shop and Audio install shop in NH. I saw this thread and was curious i have to say that a computer power supply is a great idea. i am going to give it a try at my shop. right now i use a bank of batterys to do my test work. But the power supply idea would take up alot less space. one thing im going to see is if i can set it up to run a head unit for the shop radio. Again i think this idea is a tremendous idea.


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## Aaron'z 2.5RS/WRX

If you aren't using the bench all the time, a battery charger and battery is perfect for the hobbyist.. 

Then mount an old HU in the front edge of the bench (depending on construction of course) run front speaker wires to a set of bench speakers... run the other set to a compression terminal, mounted to the front edge of the bench... Then run the RCA's over to the fron edge of the bench and place a set of male to make connection block out, so you can quickly and easily plug in RCA... done..

As for the power side, again, some terminals on the front edge of the bench, (HU powered from here as well) 

power/ground could easily be connected via an old set of jumper cables..


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## red line auto

Exactly how i have it now. Me being a shop the batterys aren't the best of ideas. as they die on me ALL the time. i have a battery tender that i use to maintain them but with a bunch of testing they go dead fast. They are older batterys so that may be the bigger problem. But if a computer power supply would deliver the 12 volt i need i think it might be the way to go.


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## 96jimmyslt

red line auto said:


> I just happened on this site when surffing the web for informational site for car audio. i run a speed shop and Audio install shop in NH. I saw this thread and was curious i have to say that a computer power supply is a great idea. i am going to give it a try at my shop. right now i use a bank of batterys to do my test work. But the power supply idea would take up alot less space. one thing im going to see is if i can set it up to run a head unit for the shop radio. Again i think this idea is a tremendous idea.


It will run a head unit fine.

In theory, it will power up to the maximum wattage and amperes of the power supply

Head units use very small wire already, so that's no problem.

I am going to combine all the 12v wires on my old power supply and see if it powers my sony xm-4045 and a pair of polk db 651's


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## ChrisB

I have an IOTA DLS55 that also doubles as a battery charger and used Anderson Power Poles for quick disconnects. One set goes to distribution blocks and another set goes to heavy duty battery clamps like those found on jumper cables. The power poles make life easy for switching between the two.

I use a Clarion DXZ785USB as my source, mainly because I can use CD or my iPod for testing. I had an Alpine prior to that, but it is now in my sister's car. Regardless, direct iPod voltage for sending signal to most amplifiers via headphone out to RCA in SUCKS!

For measuring audio signal, I have a USB Mic Mate and a Countryman Type 85 Direct Box. I really need to upgrade this part to something that will allow me to send signal on the input side and measure the output side while providing phantom power.

For measuring electrical signal, I have four 4 ohm/250 watt dummy loads from parts express, a Fluke True RMS meter, a Crapsman meter, a Sencore CRT oscilloscope, and a Velleman handheld oscilloscope. I would like to get a couple of ammeters, but good ones aren't cheap.


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## red line auto

i was talking to a friend of mine and he has doen this befor. and he said for simple testing a power supply would work the best. We are going to set one up and my shop to run the shop radio. Will post pics of what we do and how we did it once its done. but as i said befor this is a awsome idea.and i will be using it.


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## 96jimmyslt

red line auto said:


> i was talking to a friend of mine and he has doen this befor. and he said for simple testing a power supply would work the best. We are going to set one up and my shop to run the shop radio. Will post pics of what we do and how we did it once its done. but as i said befor this is a awsome idea.and i will be using it.



All you do is hook up the 12v+ from the power supply to the 12v+ on a head unit or amp.

Use the 5v+ for the remote (since power supplies have only one 12v+ per line)

And obviously use ground for ground.

I just took a video but it's 400mb so it will take a while to upload.

It's very, VERY straight forward.

You basically just calculate the wire size you need and double the wires on the power supply to equal to the amp's required size.

So if you wanted to run 500w rms I would recommend bundling up a couple of the 12v+ wires to make 8awg.

Just make sure the power supply has over 500w (I would recommend DOUBLE the RMS) and at LEAST the same amperes that the amp needs.

As you know, the amp will not pop the fuse unless under extreme circumstances, so it's not using all, lets say, 30 amperes if the fuse is 30 amperes (like my xm 4045)

It all depends on what you are going to run.

Again, VERY simple stuff!

I might take a shorter video so it uploads quicker and cuts through the un-important stuff.


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## 93accordlxwhite

I'd appreciate a video 96jimmy, seems like a handy thing to have around especially if it's easy and cheap


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## red line auto

i get what your saying here. and a video would be AWSOME. I am going to build one tomorrow and see how it works out for what i am trying to do. Now it time to go threw all my old power supplies i have in my shop and find a couple of bigger ones.


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## 96jimmyslt

93accordlxwhite said:


> I'd appreciate a video 96jimmy, seems like a handy thing to have around especially if it's easy and cheap





red line auto said:


> i get what your saying here. and a video would be AWSOME. I am going to build one tomorrow and see how it works out for what i am trying to do. Now it time to go threw all my old power supplies i have in my shop and find a couple of bigger ones.


I wouldn't recommend using older power supplies one bit. They lack the features that you would want, usually.

I have 2 uploading now. one 20mb uploading via ipod (5 minute eta) and one 400mb from my computer.

I tried to be as quick as possible with the ipod one to get it up quicker.

I will also be testing a JL 12w3v3-4 and p500-2 on this power supply after bundling the wires up as thick as I can.


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## red line auto

when i say old im not talk really old im talking the one i took out of the shop Graphic arts comps. i need more power to run them. i know the older ones are more unstable than would be ideal for this idea to work to its fullest


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## 93accordlxwhite

Wow thanks!


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## 96jimmyslt

red line auto said:


> when i say old im not talk really old im talking the one i took out of the shop Graphic arts comps. i need more power to run them. i know the older ones are more unstable than would be ideal for this idea to work to its fullest


Well ANY power supply will work for a head unit.

Head units use almost no power by themselves, to my knowledge.

I would like to point back to the stock wiring thickness for head units for this example.

Power a couple speakers from the head unit will use a little more power obviously, but if the other threads are correct and true, they won't use more than 25 w each.

So a 100w power supply will theoretically be fine, but it's not recommended to use an amplifier or power supply at full tilt. (get a 1000 w rms for 500w sub, etc)

I tried to post this but I kept getting internal sever error.

*Short version:​*
http://www.youtube.com/watch?v=n3512MOpRek&hd=1

*Long version:​*
http://www.youtube.com/watch?v=Xt9ANqBfbzc&hd=1

I also just hooked up the power supply to the p500-2 and jl 12w3v3-4 and it hits HARD with only one single 20awg power wire.

This amp required the use of 12v+ on both b+ and remote.

Took the video, it's uploading right now. Will edit with the player in about 30 minutes (200mb video)

ALSO: after this I will hook up both the sub amp and the highs amp and see if I can get a complete system running off this one 500 watt power supply.

I was really amazed at how hard the 500w rms sub and amp hits on just one 20awg wire... The sub amp is at half gain though.

Here is a link on how to "short circuit" the power supply motherboard pins to power on

How to Convert a Computer ATX Power Supply to a Lab Power Supply - wikiHow

Of coarse most of the steps are optional and you really only need to turn the power supply on and cut a few wires to get it working car audio applications.

Apparently *GREEN* is the "DC on" wire you will need to bridge.

Note: some amplifiers or head units will require a 12v+ connection for the remote turn on. The sony xm4045 only required a 5v+ and probably would work with a 3.3v+ - all available from a computer power supply.

Furthermore, I would recommend using a head unit or equalizer for a sub since, when testing this, I encountered WAY too many voice frequencies when running the phone directly to 3.5mm with an RCA adapter into the sub amp, EVEN WITH THE FREQUENCY RESPONSE ON 50Hz!!! Which usually kills all voices in the car.

You can use as many powers supplies as you like for this. A small one for a head unit or 2, a bigger one for a high pass amp, and an even BIGGER one for sub amp.


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## Phreaxer

This is by far my favorite thread that I've started and apparently it wasn't as dumb of a question as I thought it was. lol


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## 96jimmyslt

Phreaxer said:


> This is by far my favorite thread that I've started and apparently it wasn't as dumb of a question as I thought it was. lol


I installed a head unit in my computer to test CD's so I didn't have to go out to the car to test them.

This was around 5 years ago.


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## Phreaxer

Just watched your videos. Thank you very much for putting those together. They put all the descriptions in this thread into a form that even I could follow along with.  Now I need to get into the boxes in the garage full of old PCs and PC parts to see what kind of power supplies I have in there. lol


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## 96jimmyslt

Here's the sub amp

Again, VERY surprised it hit this hard.

http://www.youtube.com/watch?v=liPgckbeYH8&hd=1


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## red line auto

i am blown away at how well this worked for you. after seeing this i know it will work perfectly for what i wanna do. All the videos helped put what we have been discussing in to context and makes it alot easier to understand.


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## Nismo

96jimmyslt said:


> Or just buy a computer power supply and be done with it


You can  all you want. I've been doing this stuff going on 15 years now. I'm constantly working on how to misuse something and make things work. Yes, I've used good, solid Antec computer power supplies, and the RS power supply. I've had them shut off on me. Just an observation in case someone ran into stuff shutting off on them.

Eric


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## wannabesq

What I did, was use a Molex extension cable, so I wouldn't have to hack up the PC power supply, I just can plug it into the hard drive power cable. 

One thing, is older power supplies (like Pemtium 1 and earlier) had most of their power on the 5 volt rail, and hardly any power on the 12 volt side. I would look for an amplifier that has a single 12 volt rail, as it's easier to see what kind of power it can put out. Many ATX Power supplies have multiple 12 volt rails, which won't help a single amp very much. I guess it could be handy to have multiple amps hooked up, but at that point, a single rail is still easier. 

Also, some power supplies are "modular" and only have empty connectors, rather than a bundle of cables, which would greatly simplify it's use for 12v car audio applications, as you would only need a single cable to be plugged in.


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## SLICKDSG

Yes , I am gonna try this in the near future . What about modding the power supply internally to accept bigger cable ?


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## 96jimmyslt

SLICKDSG said:


> Yes , I am gonna try this in the near future . What about modding the power supply internally to accept bigger cable ?


What about it?

You are limited to the board's solder point.

I mean, how big of an amp/series of head units/amps are you planning on running?







^ that's the 3.3v line. Just bundle them together.

I would really like to know your reason for asking that question, though.


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## goodstuff

I use three power supplies I raped from various old broken computers to power 2 amps and a kicker 2 way active crossover. One amp is a pioneer 40x2 for the 6x9's and the other is a kenwood 45x4, two channels bridged feed 90 watts to the busted ass JL 12w0 in a ported box. I use a discman for the source. Req taught me how to do this years ago. I'll get a shot of it tonight if I can. Works great for testing head units and small amps and any other small 12v power items. I set mine up so they are on when ever they are plugged in, they can be set up to be turned off and on with a switch but I didn't want to do this as I would rather leave them unplugged when not in use. Never had a problem with them other than when it was really cold, around zero out in the garage they didn't want to turn on right away. I had to turn them off and on a few times and they were fine. Kickass idea and great way to not spend any money on store bought power supplies.


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## goodstuff

heres a shot from long ago.

S5030360.jpg picture by damagedd - Photobucket


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## yuri

guys , i thought i would share some of the items i use for my garage set up .
these are main items i use for testing and comparing .....

the most important ...... power supply .

hawker battery .. 12105f weighs in at 101.4 lbs 










as a back up a a optima 5.5 









also a vibe 50amp constant power supply ..










i have never needed to use the optima or the vibe power supply as the hawker has taken everything i trow at it , sometimes 6/7 large amps running at once ......

i use a trickle charger to keep it fully charged ,which i disconnect when listening/testing .










i have 7 vibe fast plugs connected the the hawker . allows for easy and fast connecting of amps etc. 













some other items i use a lot are a source switch , great for comparing heads units side by side , i use the same cd in the head units ,same amp and same speakers and the switch to flip between ,,,


you can also connect the switch backwards to compare amps side by side from the same head unit 










the speaker switch ( on the right ) makes it easy to compare sets of speakers side by side from one amp or head unit .... 


something else i have is two pairs of the same speakers , i use when comparing amps side by side . one set connected to each amp and use the audio switch to flip between them ..










some things i use are a active alpine x-over ,allows me 4 way control 









i use a kenwood 1023 as my reference amp .
rated @ 2x 200w rms and 1x 600w rms ,, this actually pumps out over 800w rms @4ohms mono , a fantastic sub amp as well a great sq amp .













and some genesis amps (SM60's & B40's) for components and active use 










all my testing and comparing is for my own pleasure /fun , nothing scientific about it .. 
check out some of the toys i have been recently playing with ..
http://www.diymobileaudio.com/forum...ical-advanced/108149-ghetto-garage-setup.html


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## chad

Nismo said:


> You can  all you want. I've been doing this stuff going on 15 years now. I'm constantly working on how to misuse something and make things work.
> 
> Eric


Amen


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