Archive through January 01, 2005

 

Anonymous
 
well im worried about draining the car battery whilst running the sub.
at the moment i dont think the battery is up to powering the 6x9's and the sub for long without the engine running... not only that i dont want to wire it somewhere into the wiring loom.
 

Unregistered guest
hey, im sure you have heard this a million times, but i am wondering how to use an old car stereo with an amp and two speakers, in my house; and what is involved in wiring it to play on 110volts from an outlet, or if thereis a better option. If i get a response i will give more details if needed about the stereo/amp/speakers.
Thanx
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 203
Registered: Jun-04
Read all the postings i made above.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 204
Registered: Jun-04
Use a second battery for extra power and use a battery isolator (simply two high current 80-120 amp LUG style diodes) to the second battery that way the cars alternator will charge the battery when the car runs and while it's in use it won't drain the battery that starts the car. Good for beach/tail-gate parties when you're unsure of the run time of your battery 'depends on the volume'. The louder you have it the more power you chew up; when at low volume you can run off the cars battery with any size amp for days with low 'talking level' volume. So I don't think that draining your car battery is that much of an issue unless you're having extended play periods at a loud volume 'without the engine running'. Also when running the wire to the cars battery run a large 4 or 6 gauge wire 'same as you would when running the amp off the battery', this is because if you drain the secondary battery low it will draw a lot of current from the alternator to charge it and inserting a fuse (80 amp or what ever the rating of the isolator is) to protect the branch (and the alternator) between the secondary battery and the isolator would be a good idea.
 

Unregistered guest
Jonathan I have a 700watt Volfenhag amp would I hook up some home entertainment subs to it and if so how
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 205
Registered: Jun-04
Simply the same as you do in a car. Other then the power supply mod you need to power a car amp. This also depends on your speaker configuration and impedance. and what audio source your using from your amp/sound source EX: speaker level output's or line level output's.
 

-----CHOPPER-----GUY.
Unregistered guest
hey got question, on my older house amp, i want to switch into mono but theres no strait mono switch, as is the only thing i found for mono was a button that says "mono/fm mute off" does that switch the amp into mono? and if so how do i hook up properly? do i use A channel and use left and right or do i use right or left side and use channel A&B if so, then plz tell, ive blown yes 4 house amps in the last 3 weeks, more than 1 amp a week lol, so i dont need anouther, your imput would be appreaciated thx.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 210
Registered: Jun-04
A mono switch on a house receiver just makes the sound between the left and right combine, it don't bridge the channels together if you plan on using it as a mono sub amp. Don't try to bridge the amp to a mono sub and don't over load the amp, read its rated Impedance load it can handle EX most house amps can only use 8-16+ ohm speakers so a 4 ohm car speaker is too much load. But most stereo amps will power two 4 ohm speakers on the A if you don't have any other speakers on the B.
 

New member
Username: Kuwitis

Manila, San juan Philippines

Post Number: 1
Registered: Sep-04
hey i got a question,i got a 10" 300 watts w/ dvc subwoofer 4 ohms and i want to hook up to my car amplifier 600 watts to my dvd LFE for my home theater, but i want to know can atx computer power supply can exactly gives the right ampere to my car amplfier with no strange noise or something .... ?...pls... help me...
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 215
Registered: Jun-04
Go by the fuse rating of the amp, that's the easy way to figure out the peak load the power supply will ever see.
 

Unregistered guest
i have a klh 10" amplified home audio subwoofer.
it has a fuse selector on the back. Can i put it to 60hz or 210 WATTS or 120 VAC and just run it off the car battery or something?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 234
Registered: Jun-04
a 110 volt or 220 volt selector it must be. Powering house audio gear in the car is a lot more complicated and power inverters are too noisy for the task.
 

New member
Username: Jokerxg

Palm Coast, Florida U.S.A.

Post Number: 1
Registered: Oct-04
so whats the best thing 2 do?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 237
Registered: Jun-04
I'm not sure that i fully understand what your asking and what you want to do with it.
Your trying to use a house sub in the car right? Or is it going to be used in the house only? What it it going to be hooked up too?
 

New member
Username: Jokerxg

Palm Coast, Florida U.S.A.

Post Number: 2
Registered: Oct-04
I have a klh audio "10 woofer with a built in amp.
Its for a home theater system. i was wondering if i could hook it up in my car without a power converter. i was wondering if hooking the power cord directly to the battery would blow a fuse in the amp. It has a fuse selector on the back of the amp so i can change the imput power.(i guess thats why) Can i turn the switch to 120 VAC, or 210 WATTS, or 60hz and directly hook it up to the battery without hurting anything?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 242
Registered: Jun-04
Its a voltage selector not a wattage selector. It can only be powered from AC voltage of either 110 or 210 volts not 210 watts. So no you can't power it in your car not without adding a new amp or reverse engineering the current amp.
 

ChopperKing
Unregistered guest
hey i have a pretty simple speaker box rate now for my 10 inch PG tantrium series subwoofer. however...it is in a 2 1/4 sqaure foot box rate now, no ports and running on 154watts of power. it sounds really good rate now but...I know of ways to insted of useing the sound of the speaker, rather to use the air the speaker moves. which is by far better much much deeper sound. i have tried to recreat this by a design i saw, i was unsuccessful. the design i heard of was like a bow inside a box, the bow was like 2 foot squared and used an 8 inch sub, in one half of the box there was a divider a solid chunk of wood, two tubes one in the main chaimber where the sub was and one much longer tube that ran from behind the speaker and through the seperate compartment and out the opposite side. could and body maby draw some sketch on paint or sometin or show me how to calculate a box size correctly for my 10 inch PG sub.(about 2 inch impadence, and around 400watts give or take it doesnt say) plz any help would be very appreaciated thx
 

Unregistered guest
ok i got a 800 watt boss amp and a sony cd player and i want to hook this all up outside of a car i got power to the amp but there r to many wires comin out of the cd player i don't know what to do help me out
 

Unregistered guest
ok i got a 800 watt boss amp and a sony cd player and i want to hook this all up outside of a car i got power to the amp but there r to many wires comin out of the cd player i don't know what to do help me out
 

Unregistered guest
hmmm just wondering...is there anyway you can hook up subs from a home stereo/theater/computer(??) to my car? lol
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 291
Registered: Jun-04
Yes and no, car speakers are special. They are made to sound and work right in small boxes. They have a higher impedance then car speakers and won't load the amp as much (4 ohms for an car speaker and 8 ohms for a house speaker 'normal values anyway'). The amp powering the speakers is more of the issue, in a car you want a car amp in a house you can use a normal house amp but you can use a car amp with a bit of work and extra expense.

What do you have for gear now?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 292
Registered: Jun-04
thacker, all (or most) decks have the colour code for the wires on the top or bottom side. If not don't try to do it yourself by guessing, take it to a installer and they will install it for a reasonable price usually, unless your in the city. Better to pay them and have them responsible for damages done, IMO.
 

4moso
Unregistered guest
err well everything in the rav is stock and i have this bose sub and it says "compatible with amplifiers or receivers 10-200W/channel. rated from 4-8 ohms."
 

Unregistered guest
okay easier question, anyone know how to calculate how much air and how big of port you need for a sub? like i said before ANY information would be appreaciated, cause to me im never done with my sub unless i start breakin windows in my loft lol
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 301
Registered: Jun-04
The simple formula is below for your port size and length. You need to know the thiele-small parameters of your driver and calculate the frequency you need it tuned to first. Then calculate the Fb (tuned resonance of the box) then you can calculate the port size (round port) and length. Use a large port size to minimise port noise. rule of thumb is; 4" driver- 1" port, 5-6" driver - 2" port, 6-8" driver - 3" port, 8-10" driver - 4" port, 10-12" driver - 5" port, 12-15" driver - 6" port, 15-18" driver - 7" port, 18-21" driver - 8" port. for a long throw driver use the next port size up because of the increased air volume it can move.
image/bmpUpload
Calculating_Fb.bmp (16.1 k)

image/bmpUpload
Port_Size-Length.bmp (23.0 k)

 

Unregistered guest
okay ill give that a try first, my speaker like moves in and out about 2 inches and its a ten inch should i just go witha 5" port? and besides porting the box properly how can i get more sound like maybe long tubes? or air blockers inside the box? any info will help thx
 

Unregistered guest
Aight, check this out, i've managed to connect 2 12" subs to a 600 watt amp from a sony home theater. I did it using a "Battery Companion" from AUTOZONE. It's a 1.5 amp (trickle charge), fully automatic, battery charger/maintainer. Its not that good cause it would always go red, meaning it was overcharging. NOW HERES MY QUESTION< WOULD GETTING A CHARGER WITH MORE "AMPS", SOLVE MY PROBLEM OF THE AMP OVERCHARGING.... THE CHARGER?
HOW MANY AMPS WOULD YOU RECOMMEND?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 317
Registered: Jun-04
If your not using a battery for storage no wonder! Even if you are using a battery, a battery maintainer will not do the job at all. If you plan on using a car AMP in the house/work shop for some time go the ATX PSU way.
 

Unregistered guest
hi i just recently been working on a backpack speaker system i just got 2, 145 watt sony xplods an a 60 watt sub now im only running a 18 watt kit type amp with 2 3000maH 7.2 volt batteries together to put out 14-16 volts depending on charge it sounds ok but i wanna step up the amp to avoid clipping im also using a ipod as the input source an it an only take about close to half the colume up of a ipod but anyway can anyone tell me if theres a car amp i can use or anything else on the cheep side or somthing i can find on ebay thats small that i can use wit the same battery packs snd will be able to give me optimal performance from my xplods and sub? any help greatly appreciated.
 

kpa62
Unregistered guest
thier 140 watt not 145 my mistake
 

ChopperKing
Unregistered guest
hey i got a question again, in my car i got two ten inch subs, now my car is a 74 super beetle so i mean they are really loud inside the cabin and they really rumble, but a little to much that they make my cd player skip when i listen loud is there a good way to stop the skippin without having to turn down the sound?
 

cody_1133
Unregistered guest
I was just wondering if all u audio geniuses ever thought about wiring a few 120ac to 12ac step down transformers in parallel to get however many amps u need then wire to large barrel diodes to use as a rectifier and ta da u have a cheap hi power power source if any one can see sumthing wrong wit that let me know.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 344
Registered: Jun-04
cody_1133, yes several problems. No regulation for constant voltage as the load changes. Very Heavy compared to switching regulators for the same power. Poor efficiency compared to a switching regulator. This type of power needs very large capacitors to reduce the ripple because of the lower frequency.
 

cody_1133
Unregistered guest
is there ne way to fix those problems and make it work?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 352
Registered: Jun-04
YES you can fix that problem, don't even think of using a transformer based power supply and linear regulators. Use a switch mode power supply and that fixes thoes problems. The cost of building a custom supply with computer ATX PSU's is very little compared to buying one.
 

Unregistered guest
i have 2 car subs, and one car amp, i want them to all work in my room, im not using a special reciever, im actually gonna use my cd player from my truck that i had it hooked up to earlier, this is possible right, and if so how? main problem is powering the amp and cd player, i just need power
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 356
Registered: Jun-04
Read the archive above. I have explained it many times before to many other people on how it's done.
 

Unregistered guest
how do i plug in an amp to my car stereo.?
i need a diagram and some directions.
 

DC power guy
Unregistered guest
I hooked up my TV to two speakers in the back of my van through an amp. It sounds great but I need and external 12 volt volume control. I found lots of 110 volt speaker controls but no 12 volt. Does someone make a 12 volt speaker volume control?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 367
Registered: Jun-04
DC power guy, what? Your thinking of PA gear you dont need that. What exactly is your setup?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 368
Registered: Jun-04
julio sanchez, Its not that simple to install an depends by model and how it needs to be hooked up. I personally recommend that you take it to a dealer/insanitation professional to install it for you. It can be complicated and then they are responsible for damage if it's done wrong.
 

Anonymous
 
123123123
 

DC power guy
Unregistered guest
My set up is, I have a 12 volt TV with RCA Jacks that I connected to two speakers in the back of the my van. I bought and installed an amp.
I now have great sound, but I can only contol the volume by the gain control on the back of the amp. I was thinking of buying a equalizer just so that a have a knob to contol the volume.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 374
Registered: Jun-04
All you need is a $3 doller dual ganged audio potentiometer from radio shack.
 

DC power guy
Unregistered guest
Thanks FryGuy.ca, I'll give it a try.
 

15YearsOldKid
Unregistered guest
but my amp has a "RMT" connector, where shall i fix it to??
is it okay to power a pre-amp on the ATX power??
an ATX needs a "Power button", as long as it is not triggered, it wont work(isnt it??)
can the ATX support both my PC running and the amp(120w, 4 channel).
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 386
Registered: Jun-04
The RMT is remote power on for the AMP you simply tie it to the positive (+12 volts or yellow wire) or place a switch in that line then you can turn it on and of.

Yes you can power a pre amp off the power supply as well as any other 12 volt device.

I had a document that I had posted above but it's in the archive now. The document will explain what you need to mod with the PSU to get it to turn on and how to expand the current as needed.

Most likely you won't be able to run your computer and the AMP off the same PSU. You'll need to measure the power requirements of the PC during boot up and heavy use to determine its load on the PSU. Then look at the fuse rating of the AMP to determine its peak load and compare the two. If you have enough head room on that PSU then you may be able to run both. If not when you turn up the volume your PC will shut down because of the PSU going into protect/over current mode.
application/mswordUpload
Using_an_ATX_Computer_Power_Supply_to_Make_a_Scalable_Multipurpose_Power_Supply.doc (51.7 k)
 

Anonymous
 
I hooked up a dual ganged potentiometer from Radio Shack, between my van TV and amp, like you recommended. Now I have some volume contol, but I was hoping for more control. It works from about half to full volume. Is there a better potetiometer I can use. Thanks. You have been a big help.
 

15YearsOldKid
Unregistered guest
is it okay to use the molex power connector(the power for CD-Rom)?
i found out that if i short the "PWR-ON" once when u got it connected, the power currents became active, can i just use that as Power on/off???
Is this dangerous? What's the cost if it fails??
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 387
Registered: Jun-04
You may have the pot hooked up backwards? The source should feed into the outside pins on the pot then you should have full volume control on the knob.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 388
Registered: Jun-04
The power on to the ground with a switch can be used to turn the power supply on and off.

The Molex plug can be used to get power but it only has 16 gauge wire so if the current to the AMP is any more then say 3-6 amps then you will need to use a few connectors (or more) together. Then you'll get good power to the amp. Your amp should have about a 15 AMP fuse, so you will need to tie all the plugs you can together on the power supply. The longer your wires the heavier the wire you'll need or more small wires together to carry the power and minimize power loss.
 

CKKC
Unregistered guest
hey, i got i think a good question. can you hook two house amps together? but thats not the only thing. can you take 1 channel or two if monoed, of each amp and run them into the same speaker? i pretty sure thats what you do with car amps at least. but also my house amps are old school, from like 1988 or something like that one is arund 300 watts and the other around 150watts.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 394
Registered: Jun-04
From a technical standpoint it's possible to do.

But you need to be sure of a few things:
1. The speaker out don't have a common chassis ground with the electrical ground. (If so you'll pop fuses when you try to bridge them together)
2. They should be the exact same size amp and best to be the same exact model of amp. (This is because the other amp could push too much power through the smaller amp causing it to pop its output fuse)

To test the first requirement use a volt meter and test for continuity between the speaker ground and the chassis of the amp. If you get a low ohm reading at all then the chassis ground is common with the speaker ground and it can't be used bridged.
 

Unregistered guest
hi, i wuz wondering how to make any sort of AC DC convetrer for any car stereo amp to work in a house 240v supply... if u could suggest the main parts needed and the basics of making one!
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 396
Registered: Jun-04
Use the above plans and change the PSU switch to 220-240 volts.
 

Unregistered guest
I too am trying to set up a car radio/CD/MP3 player in my house. I've read the entire thread, but I still have a few questions. I plan to follow the suggestions and use an ATX PSU, but I'm struggling with the bounceless switch. I read FryGuy's doc about a scalable multipurpose PSU and the UT specs for a bounceless switch (http://ece.utep.edu/Faculty/webusev/ee2369/EE2369_lab6_03F.doc). So here are my questions:

Bounceless Switch
1. What size transistors do I need? Where can I buy them (my local Radio Shack sucks)?
2. What gauge wiring should I use?
3. Do I really need a 5VDC SPDT switch? I can't find one anywhere. Is it possible to use a higher rated switch (i.e., 12V)? Can I wire it differently and use a SPST?
4. Are there pre-made bounceless switches that cost under $10 that will work?

Back Up Power
1. When I cut the power supply with the toggle switch, I want to maintain the station presets and the clock settings. The only stand by power is +5V. I assume this won't power the memory so I was thinking about using a 12V lighter battery (http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5 F009%5F014%5F002%5F000&product%5Fid=23%2D279). Would this work?
2. If I hook up a battery, I assume that I would hook up the stereo's 12V "always on" (i.e., cigarette lighter lead) and the stereo's ground wires. Sound reasonable? Do you think I'll need to replace the battery every 2 hours or should it last me a while?

Other
1. Do I need to power the fan or will convection cooling be sufficient (I'm only powering the head unit and 2 or 4 6x5" speakers)?
2. Has anyone developed or seen an instruction guide to do this (similar to FryGuy's scalable multipurpose PSU doc)?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 426
Registered: Jun-04
No you don't need bounce less switch you'll run the PSU all the time for the +12 to keep the time. Just tie the PS-ON to the ground. The wire gauge depends on the wire run and total current you have going threw the wire. 10 gauge for a short run can do 30 amps longer run you will want a larger wire maybe an 8 or 6 gauge.

The battery can be charged by the ATX PSU because the voltage differential is high enough. To limit the charging current and a diode to bypass the current limit for the load draw (be sure to use a large high current diode not the little radio shack ones). You can use a simple incandescent light bulb (more current hotter the bulb and more resistance to the circuit to limit the current, you'll need to play with bulbs in series and/or parallel to get the right charge current). (Your link above didn't work for me so I'm not sure what the battery was but it should be a rechargeable NiCad type)

You will need the fan because if you run it hard at any time you can burn it out, best to get a PSU with a thermal controlled fan or buy a replacement fan that's thermally controlled.

I have never seen another guide for this mod that's why i made a basic one myself. Maybe I'm the only one crazy enough to try it and prove it can be done. Electronics, isn't it fun :-D
 

Unregistered guest
OK, so if I tie the PS-ON to the ground, it will always be on and sending juice to the head unit (HU). In this case, should I hook both the 12V constant and turn on leads from the HU to the +12V from the PSU?

If the HU is turned off, I assume the draw from the PSU (and hence the draw of household current) drops to a very low level. Is this a fair assumption? (I want to be sure this thing isn't putting out a lot of heat when not in use.)

A very brief search didn't pop up any compact-sized NiCad of NiMH 12V, only Alkaline. Could I put a large capacitor in place to give me enough power for a 2-3 minute power loss? If so, how large should the capacitor be if it's only powering the HU's memory? Any thoughts?
 

15YearsOldKid
Unregistered guest
is it okay to just use an AT power supply? Is it easier for that? AT power supply already has a built-in switch, can it function on my amp?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 430
Registered: Jun-04
The power draw will be low with it turned off use a amp meter to see if the draw is acceptable. You may want to place a switch on the lead from the HU that normally is switched by the ignition switch (ACC) that may reduce the power consumption even more.

You can get a lead acid battery from radio shack that's 12 volt or build a battery pack of NiCad's to be 12 volts (they have battery holders also for this).
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 431
Registered: Jun-04
An AT PSU may be used in some cases but most AT PSUs need a +5 volt load to have a sustained +12 volt rail at the full rated current. That's a problem unless you want to waste 35 watts of load on the +5 rail with a load resistor.
.........

I didn't think so.
 

Dustin Jive
Unregistered guest
i just got a car cd player and a 120 watt car amp from my friend for free. i dont have a car and want to hook them up in my room. i have two 800 watt subs. i realize i need a ac to dc converter. both the cd player and the amp take 12v dc. do i have to buy two converters or could i buy one 24 volt converter and split the power between the two? or does it not work that way? if anyone knows how to do this without buying two converters or knows how to make a converter i would be very thankful. please give me any info possible. or at least tell me what the exact kind of converter(s) i need. thank you very much
 

Dustin Jive
Unregistered guest
i just got a car cd player and a 120 watt car amp from my friend for free. i dont have a car and want to hook them up in my room. i have two 800 watt subs. i realize i need a ac to dc converter. both the cd player and the amp take 12v dc. do i have to buy two converters or could i buy one 24 volt converter and split the power between the two? or does it not work that way? if anyone knows how to do this without buying two converters or knows how to make a converter i would be very thankful. please give me any info possible. or at least tell me what the exact kind of converter(s) i need. thank you very much
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 441
Registered: Jun-04
If you're going to buy a converter, be sure to get a 12(~13.8) volt one, not 24 volt. You'll need either a large converter or a few smaller ones to power it all. I have a document above on how to mod an ATX PSU to make a scalable power supply if your comfortable with a slight moding of the wiring and custom work.
 

dustin jive
Unregistered guest
so fry, how much is one large converter? and how many volts would it be? so culd i get one 12 volt converter and split that so that it powers both the amp and the cd player? or do i have to get two 12 volt converters. both the cd player and the amp take 12v. also on the cd player there is blue wire called the Auto antenna. the instructions to the amp say the auto antenna wire provides 12 volts to turn on the amp.could i connect that wire to the remote turn on inlet on the amp then bridge a wire to the 12v power inlet to power the amp? sorry for all the questions but i really need help. Thanks
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 444
Registered: Jun-04
A single large power supply can power it all. If you buy a high current switching power supply you're looking at a lot of money, about $200+ depending on the power needed. This is why I moded an ATX computer power supply to do the same job. It has proved to have some problems on some power supplies that are non-standard but for most it has worked well. This can save you a bit of money if you don't mind doing a bit of electrical work.

The power antenna on most Head units should work but a few have noted that on some the power antenna only works when the radio function is selected on the head unit. You'll have to try it to be sure this is not the case on your head unit.
 

Unregistered guest
Jonathan, thanks for the help. I finally have all the parts I need (I think) and I have read your paper a couple times. Since my setup is slightly different from the one you describe in your paper, I plan to set it up as follows:

(HU = head unit, PS = ATX power supply unit)

* Cut extra wires on PS (red, orange, grey, purple, blue, brown)
* PS_ON (green) to PS Ground (black) - Always On
* Add a 10A fast-blow auto fuse between PS +12 (yellow) and HU
* Wire HU constant power (yellow) and HU ignition power (red) to fuse to PS +12 (yellow).
* Wire HU ground (black) to PS Ground (black)

So I have a few additional questions...
1. Do you foresee any problem if I just pigtial the HU's constant power and ignition power together?
2. If I'm not shutting down the PS, do I even need to wire up the HU's constant power?
3. Any thoughts on the best way to cut the extra wires on the PS? There's very little room in the box and some of the connections have 5 or more wires (e.g., red & orange).
4. Does it matter which +12 and which ground I use? There are three connections on the board for +12 (yellow) and three connections for ground.

Let me know if you see any problems with this setup.

Thanks again for all your help.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 446
Registered: Jun-04
The constant power keeps the time and other things in volatile memory (gets lost when power is removed) (like the spot on the CD that was last played to resume from, etc). The ignition power supplies power to un-necessary sections of the circuit. My only concern would be the standby power used if you keep the ignition wire on the PS all the time. I would have a switch to reduce the standby current when it's not used.

The common coloured wires on the PS are all connected to the same spot on the PSUs power rail. I would remove the wires you don't need by either cutting them as flush as you can or using a soldering iron to remove them all together. Then replace the wires you need with a larger gauge wire in your case a single 12-10 gauge wire would be fine for the ground and the +12 rail.

Hope that answers all your questions.
 

poiyui
Unregistered guest
Thanks!
 

Soberer
Unregistered guest
I have heard that a switching power supply can cause noise issues? To those who have successfully done this, how does it sound?

I have a 300 watt rms car amp I'd like to use to power a subwoofer for my home theater. It looks like pyramid has a couple AC > DC convertors for around 60$ (on ebay) that supply ~20amps. Do you think they would do a better job than the ATX PSU?

What happens if I underpower my amp?

Thanks, I appreciate any responses.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 450
Registered: Jun-04
They can cause noise but the issue is not the cleanliness of the power but with ground-loop feedback.

This is if the source and other gear that's connected have grounds that are on a different potential plane that will cause noise. Connecting all the gear to a common ground can eliminate that. The problem that I hear most is with computer sound cards and using an AMP. A computers sound card will have a different ground potential then the external amp causing noise. A solution would be to use an audio isolator.

You can get an ATX PSU with 25 amps (@ +12 volts) for $20-25 if you look around. In Either case you'll still have the same problem and there is no simple power supply or any one thing that will solve all possible problems you may encounter.

If you under power an amp it will just force the power supply into over-current protection mode and the AMP will die until the over-current condition is removed, what you get is the AMP kicking on then off. Just reduce the volume or increase the current of the power supply (or power supplies that you can parallel for higher current).
 

dustin jive
Unregistered guest
hey fry or anybody else who can answer , i just bought two 12v dc converters. when i hooked them up to my head unit. it turned on very weak then shut off. also when i hooked my amp up to my personal cd player it would only go so loud before it started to jumble the music. both using the volume on the cd player and the gain on the amp. im assuming that 12volts just isnt enough. would a 13.5 volt converter do the trick.? or is there is certain wattage/amps you could recommend?
and if i am using the power from the auto antenna to power my amp should i get more than a 13.5 converter. help would be very much apriciated.
 

dustin jive
Unregistered guest
hey fry or anybody else who can answer , i just bought two 12v dc converters. when i hooked them up to my head unit. it turned on very weak then shut off. also when i hooked my amp up to my personal cd player it would only go so loud before it started to jumble the music. both using the volume on the cd player and the gain on the amp. im assuming that 12volts just isnt enough. would a 13.5 volt converter do the trick.? or is there is certain wattage/amps you could recommend?
and if i am using the power from the auto antenna to power my amp should i get more than a 13.5 converter. help would be very much apriciated.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 453
Registered: Jun-04
The power supply needs to be able to supply more current to properly power it all. That's why it cuts out and/or goes jumbled when you increase the volume.

A 12 volt power supply actually puts out 13.8 volts if you measure it. Its some 15% rule they have for power supplies output voltage. EX: A 5.0 volt power supply is actually made to put out 5.75 volts. It's a strange but true fact about power supplies.

Power equals voltage by the current.
EX: 12 volts X 2 amps = 24 watts
So the current required depends on the power needed. The voltage stays the same.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 454
Registered: Jun-04
If you're using the power antenna wire to power the AMP you will burn the switch/circuit out. You can use the power antenna to the REM on the amp. That will turn the AMP on when the head unit is turned on.
 

Dustin Jive
Unregistered guest
so what voltage for a converter would you recommend?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 456
Registered: Jun-04
You didn't get what I was saying to you above. I was saying that 12 volts isn't actually 12 volts when talking about power supply voltage. A 12 volt power supply almost always puts out 13.8 volts. Same as everyone else, personally when I calibrate a power supply it's always 15% higher then the rating on the tag, it's to allow for voltage drop with current
 

Unregistered guest
Well, I gave it a try; but there seems to be a problem... I removed the board from the ATX PSU and removed all the excess wires using a solder iron. Was careful to ensure the solder remaining on the board didn't spread and cause a bridge across two rails. Then, I hooked the green wire (PS_ON) to a black. Hooked the head unit's ground to a different black (I left three on the board) and taped the final black. Then ran the PSU's yellow (+12V) to a fuse holder (32VDC) w/ a 12V/10A fuse. Then I taped the final yellow (I left two on the board). Finally, as a test to see if it worked, I ran the head unit's yellow (Battery) and red (Acc) to the other end of the fuse holder, pigtailing all three wires.

Nada... I think the fan turned about 1/4 turn when I first powered up, but nothing since then.

Any ideas?
 

Unregistered guest
Could the problem be related to pins 14 and 15? I didn't short them out b/c I thought that would cause bouncing and damage the PSU.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 459
Registered: Jun-04
The pins 14 and 15 are for the PS_ON they need to be tied together for the PSU to turn on. It's the green wire and the black. I soldered the green wire to the rail with the black wires, holding the PSU on. Then I just use the switch on back to turn it on and off manually.

The bouncing problem is handled by the PSU's onboard debouncing circuit now, so my document above is out of date.
 

Unregistered guest
Let me make sure I understand... Soldering the green wire to the black rail *is* shorting out pins 14 and 15 (so is tying them together). Since the grounds are more than one pin (i.e., pins 3,5,7,13,15,16,17), does it matter which ground is used?

When you mention that you use the switch on back, what kind of switch is it? My PSU doesn't have a switch that I can see(although I plan to wire one between my HU's Acc wire and the PSU.)

Any idea why it isn't producing any power?

Thanks for all your help. I really appreciate it.

All the best...
 

Anonymous
 
hi i am planning on useing an atx power supply to power 2 12 inch subs with a 500 watt amp just wondering if a 350 watt psu will be sufficient or if i should go with a 4-500 watt psu thanx
 

Unregistered guest
Can anyone tell me how exactly to power my 300 watt car amp in the house? I want to put some speakers in mty couch so that it rumbles the person sitting there. is this possible with the amp that i have and if so how do i go about getting power to the amp safely? E-mail me any answers Peachy_30_5@yahoo.com Thank you very much
 

Unregistered guest
Hey, I need help installing my amp, cd player, and my 2 JL W3's inside of my car. I know alot about electronics, but I have tried to do it by myself, and I have no idea how to do it. I have the Amp and the stereo powered straight from the battery. So there are 4 separate wires. Then I have 2 audio plugs from the amp to the CD player. I have the JL's bridged to the amp since it is a 4 channel amp. I plug in everything, and the CD player shows that there is sound coming out of it, but there is no sound coming out at all. I have no clue what to do. Help please. Email me at WVBUDS@hotamil.com if u can help me. Thanks alot. Also, My amp is older, and it says 40x4 on it, and i guess that is only 160 total watts, and I have no clue about my JL's b/c my brother gave them to me. I think he said they had 600 watts a piece. I wonder if they are just not being pushed, but I should at least hear some sound from them.
 

Anonymous
 
Your saying "Ground all unused wires", does it mean jumble all active current wires together, except PS_On and one GND to connected together?
My ATX power supply says that is 10A, 400w,
does that mean i need another power if my AMP is 800w??


 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 460
Registered: Jun-04
Where did I say to ground all unused wires? That's not what it's called, what it's doing its called paralleling. That is all common voltage wires are tied together, same idea as jumping a car with a pair of jumper cables, it gives the connected systems more power.

Go by the current rating of the fuse on the amp. An amp is rated by peak power it's not the actual power and also actual power depends on the loading of the amp with speakers.
The best idea is to power to the same current as the fuse rating for the amp, then even if you add speakers to the amp later you will still have the power capability to run the amp properly.


The document is above on how to mod the power supply. The wiring of the amp is not covered in the document and assumes that you have some basic knowledge.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 461
Registered: Jun-04
poiyui, I have no idea what's going on, when you connect the green (PS_ON) to the ground that will turn the PSU on. If its not staying on after connected to the amp then something is seriously wrong.
 

IB6UB9 69er
Unregistered guest
now i looked in here before to figure out my question and i found something but it was a little technical for dumb me. My question is how do you calculate port length correctly, and where is the best place to put it in the box? I got speakers and an amp for my car but I dont wanna spend 2 - 300 dollers getting someone to make me a box. the dementions Im using are 25" long by 15" wide by 12 inches tall, rate now I got 2 PG 10" subs. Where should I put the port(s) and how many and how long should they be? any info would help cause my box need some help.
 

poiyui
Unregistered guest
I think my problem is that I'm not meeting a minimum load requirement. It seems that most PSUs require at least 10-20% of their max as a min load. Also, I was told that it might be helpful to leave the +5V wire on the unit and hook it up to a small LED or something just to know when the sucker is working.
 

READ THE THREAD!
Unregistered guest
"is there a really easy way to convert a car amp to run
off a outlet or whould i need to get a house amp."

DOES ANYONE KNOW HOW MANY TIMES THAT HAS BEEN ANSKED AND THE ANSWER HAS BEEN GIVEN?

OR ON THIS THREAD:

https://www.ecoustics.com/electronics/forum/car-audio/4033.html

PEOPLE READ THE THREAD BEFORE YOU ASK THE SAME QUESTION A MILLION TIMES!

IT ALLREADY HAS AN ANSWER!
 

my head hurts
Unregistered guest
to "read the thread"
i checked ur link and i doesent say anything about how to connect the amp to the outlets i kno u need a converter that has a 120v input and that has a 12v output but there are 2 wires on the thing is the black one negative or positeve and on ceiling fans the white wires are neutral and that confuses me cause there are 3 wires in an outlet and which one is the posotive and what do u do w/ the other wire that comes from the oncerter on a 2 prong outlet?
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 471
Registered: Jun-04
Most just plug the PSU in the wall and don't need that information.

The black wire is the hot wire, white is the common and green is the earth ground (non current carrying wire).

The green ground can be removed but I don't recommend you do that. You can also tie the green wire to the case ground, that is what I suggest you do with the green wire if you can.

Its for safety and the common ground can eliminate ground-loop feed back problems (hum/buzz noise).
 

READ THE THREAD!
Unregistered guest
Fryguy, i dont really understand wat do you mean by "paralleling" is it like, connect all unused wires together?
i have a problem just like DDW last time, but albeit different.
I tried not to do the "paralleling" first, connected it to AMP, and it works, so i assume, all equipment is alright, but after i do "paralleling", connected all wires together, the power supply seems to cut off itself, the fan turned for a few secs, and it goes off.
Did i connected the wires wrongly?
or i should connect all to a circuit board?
 

READ THE THREAD!
Unregistered guest
"is there a really easy way to convert a car amp to run
off a outlet or whould i need to get a house amp."

DOES ANYONE KNOW HOW MANY TIMES THAT HAS BEEN ANSKED AND THE ANSWER HAS BEEN GIVEN?

OR ON THIS THREAD:

https://www.ecoustics.com/electronics/forum/home-audio/4033.html

PEOPLE READ THE THREAD BEFORE YOU ASK THE SAME QUESTION A MILLION TIMES!

IT ALLREADY HAS AN ANSWER!
 

my head hurts
Unregistered guest
ok thanks fryguy
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 472
Registered: Jun-04
"paralleling" is the wiring of two or more power supplies or devices in a "parallel" manner.

Its the same as using jumper cables on your car, what your doing is paralleling the batteries together to get more power (higher current).

You tie the positive of the power supplies together and the negitive's of each together, this will give you the combined power of both power supplies to power the load. You may have tied a positive with a ground or another power rail together. That will cause the power supply to go into protection mode.
 

Anonymous
 
no, i only use one power supply, do you mean i can only ground the same wire from the same sets? e.g, from the same molex connector
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 473
Registered: Jun-04
The the hookup is simple. only the same colour wires go together, or remove all the small wires and replace with a single larger gauge wire.

The yellow it the +12 that is the PWR on the amp and the black it the GND or common.

To hold the amp on use a short jumper wire from the amps PWR terminal to the REM terminal. Then when you plug=in or turn on the power supply the amp will be on, with no need for a second switch.
 

Unregistered guest
Hi guys, i have read the above posts and maybe i just diddnt understand it - so i may be asking a question already answered... but here i go

I have 2 EIGHT (8) ohm kickers hooked up to a old 100wx2 amp. I have a home theater receiver that out of the sub pre-out, i have a rca splitter and put in the right and left into the other amp to get the signal to it... so far it's worked great. i have a few questions - 1. I have htem together in a sealed box. would 2 single ported boxes be better? 2. i'm thinking of getting a kicker 8 ohm 15 inch sub, how can i go about powering that without having to use a battery or something that would blow up everything in my house? They dont make an easy "plug into the wall and plug your dc into that" thing that could power a car amp at 4 ohms so i could get a 4 ohm 15? thanks for any help, feel free to email and walking me through this would be greatly appreciated.
 

Silver Member
Username: Fryguy

Nova Scotia Canada

Post Number: 474
Registered: Jun-04
Read the posts above, thats what this forum talks about an it has been answered many times. I got a document that states the simple wiring and moding that needs to be done to an ATX psu, to power a car amp in the home with.
« Previous Thread Next Thread »



Main Forums

Today's Posts

Forum Help

Follow Us