Car Sub in house using PC PSU or 12v Transformer?

[Gershy13]

3 hours ago, rhyseyness said:

13A fuse on the plug would only blow when you're pulling over 3000W from the wall, so you'd probably want to change that for something smaller in case your PSU goes wrong.

As for the fuse "built in" to the 8 gauge... meh, if you're putting in your own 400W fuse on the output, probably isn't necessary.

 

Basically you want one fuse between the mains and the PSU, then one between your PSU output and the amp.

This means if there's a problem anywhere along the line, the fuse SHOULD protect your equipment.

Kettle leads should have a ground connection.

The "top" pin on the kettle end should be a ground.

Ok, how would I put a fuse on the output? The amp had built in fuses, and the power supply I'm not sure, it has short circuit protection tho...

You're saying I should change the plug fuse for a 5a?

Also, I'm not exactly sure my wire is 8 awg... it looks a lot thinner than the 4 gauge I have, it's thinner than the average kettle lead... is there a mm measurements I can take?

And yeah, I found out that there is a ground connection... I used a multimeter on the continuity setting and tested it.. 

 

[rhyseyness]

55 minutes ago, Gershy13 said:

Ok, how would I put a fuse on the output? The amp had built in fuses, and the power supply I'm not sure, it has short circuit protection tho...

You're saying I should change the plug fuse for a 5a?

Also, I'm not exactly sure my wire is 8 awg... it looks a lot thinner than the 4 gauge I have, it's thinner than the average kettle lead... is there a mm measurements I can take?

And yeah, I found out that there is a ground connection... I used a multimeter on the continuity setting and tested it.. 

 

Wait... what was your plan for the 400W fuse?

I assumed that would be going on the output of the PSU before the amp.

PSU->8 gauge->Fuse->8 gauge->Amp.

 

Yes I'd recommend you change the plug fuse to 5 amps, because the wall outlet is 240V, which at 5A will be 1200W... Even if your PSU is HORRIFICALLY inefficient, you won't come anywhere near that under normal operation.

 

8 AWG should have a conductor cross sectional diameter of approximately 3.26mm.

 

Good testing for the ground connection.

Exactly the right way to test.

 

Hope that all makes sense

[Gershy13]

2 minutes ago, rhyseyness said:

Wait... what was your plan for the 400W fuse?

I assumed that would be going on the output of the PSU before the amp.

PSU->8 gauge->Fuse->8 gauge->Amp.

 

Yes I'd recommend you change the plug fuse to 5 amps, because the wall outlet is 240V, which at 5A will be 1200W... Even if your PSU is HORRIFICALLY inefficient, you won't come anywhere near that under normal operation.

 

8 AWG should have a conductor cross sectional diameter of approximately 3.26mm.

 

Good testing for the ground connection.

Exactly the right way to test.

 

Hope that all makes sense

No I didn't plan to put one lol, I was going to go straight PSU to amp... the amp had built in 2x 15a fuses... so is it better for me to use the external 8 gauge fuse then? It's 30a

I'm not exactly sure what conductor cross section diameter means, but I'm assuming it means the copper should be thst thick, I'll go and check it after school...

 

I found lots of kettle leads lying around which we arent gonna need, so I'll probably chop the ends of one of them and we should be ok...

Thanks, 

 

[rhyseyness]

17 minutes ago, Gershy13 said:

No I didn't plan to put one lol, I was going to go straight PSU to amp... the amp had built in 2x 15a fuses... so is it better for me to use the external 8 gauge fuse then? It's 30a

I'm not exactly sure what conductor cross section diameter means, but I'm assuming it means the copper should be thst thick, I'll go and check it after school...

 

I found lots of kettle leads lying around which we arent gonna need, so I'll probably chop the ends of one of them and we should be ok...

Thanks, 

 

Ah fair enough, in that case you'll just need the plug fuse.

Won't need any others

 

And yes, that's exactly what it means.

The diameter of the copper part in the wire, or, as you say, how thick the wire is.

 

Kettle lead will be fine

 

No problem at all. Glad I could help

[Gershy13]

2 minutes ago, rhyseyness said:

Ah fair enough, in that case you'll just need the plug fuse.

Won't need any others

 

And yes, that's exactly what it means.

The diameter of the copper part in the wire, or, as you say, how thick the wire is.

 

Kettle lead will be fine

 

No problem at all. Glad I could help

Thanks, I have some pictures...

It's the "8" gauge next to some real 4 gauge... also next to a calliper

 

So all I need is the fuse in the plug? No external fuse with the 8 gauge? 

 

[rhyseyness]

11 minutes ago, Gershy13 said:

Thanks, I have some pictures...

It's the "8" gauge next to some real 4 gauge... also next to a calliper

 

So all I need is the fuse in the plug? No external fuse with the 8 gauge? 

Interesting.

I think you're right.

That looks like 2.05mm to me.

Probably 12 gauge rather than 8.

 

The 4 gauge would be fine to use btw, if that's an option.

Thicker isn't a problem, thinner is.

It will just be more difficult to get into the terminals.

 

OR! You could use 2 runs of that 12 gauge!

(Rather than 1 run of 8 gauge).

That'd be plenty of current capacity

 

Yes if your amp is fused, you don't need an external fuse with the 8 gauge

 

EDIT: Just to check, this is just between the amp and PSU btw.

The cable with the kettle plug will be fine for plug to PSU

[Gershy13]

7 minutes ago, rhyseyness said:

Interesting.

I think you're right.

That looks like 2.05mm to me.

Probably 12 gauge rather than 8.

 

The 4 gauge would be fine to use btw, if that's an option.

Thicker isn't a problem, thinner is.

It will just be more difficult to get into the terminals.

 

OR! You could use 2 runs of that 12 gauge!

(Rather than 1 run of 8 gauge).

That'd be plenty of current capacity

 

Yes if your amp is fused, you don't need an external fuse with the 8 gauge

 

EDIT: Just to check, this is just between the amp and PSU btw.

The cable with the kettle plug will be fine for plug to PSU

Yes it is between amp and PSU... that might be 12 gauge... it's gonna be a short run (less than a metre) but I might end up using 2 runs of 12... that's 2 terminals off the PSU and me twisting them into 1 for the amp side right?

I could use the 4 gauge, but it's really thick and I don't think it will fit in the PSU... also it's quite dirty.. as its old and used... its greasy and not nice to handle...

[rhyseyness]

1 minute ago, Gershy13 said:

Yes it is between amp and PSU... that might be 12 gauge... it's gonna be a short run (less than a metre) but I might end up using 2 runs of 12... that's 2 terminals off the PSU and me twisting them into 1 for the amp side right?

I could use the 4 gauge, but it's really thick and I don't think it will fit in the PSU... also it's quite dirty.. as its old and used... its greasy and not nice to handle...

Sounds perfect to me

That's what I'd do.

 

I agree the 4 gauge would be a bitch to work with.

Not as flexible either.

[Gershy13]

1 minute ago, rhyseyness said:

Sounds perfect to me

That's what I'd do.

 

I agree the 4 gauge would be a bitch to work with.

Not as flexible either.

Alright thanks, so this is the final plan lol

 

Wall socket - plug 5amp kettle lead with c13 connector chopped off - PSU - 12 gauge (2 terminals 4 wires) - amp wires twisted 

[rhyseyness]

2 minutes ago, Gershy13 said:

Alright thanks, so this is the final plan lol

 

Wall socket - plug 5amp kettle lead with c13 connector chopped off - PSU - 12 gauge (2 terminals 4 wires) - amp wires twisted 

Perfecto

4 terminals for power out of PSU, 2 for COM, 2 for V+.

And yea, 4 wires twisted into 2 (V+ and COM) for the amp.

I'm 99% certain this is what you're saying, just making sure

 

I try to picture the current flow, because it makes it easier for me to wire stuff up, so in this case:

Live from plug > PSU L > PSU V+ out > amp + > amp - > PSU COM > PSU N > plug neutral

If that makes everything more complicated for you, just ignore it, lol.

[Gershy13]

2 minutes ago, rhyseyness said:

Perfecto

4 terminals for power out of PSU, 2 for COM, 2 for V+.

And yea, 4 wires twisted into 2 (V+ and COM) for the amp.

I'm 99% certain this is what you're saying, just making sure

 

I try to picture the current flow, because it makes it easier for me to wire stuff up, so in this case:

Live from plug > PSU L > PSU V+ out > amp + > amp - > PSU COM > PSU N > plug neutral

If that makes everything more complicated for you, just ignore it, lol.

Hahahahhah no it's fine I get it lol...

Yup that's fine...

I'm probably going to Velcro or something the PSU to the amp... need to find a way to do it.. not sure it will hold Velcro . (Its carpeted) 

And as for the voltage, should I set it to 13.8v? The manual of the amp says 200w @ 13.8v

[rhyseyness]

8 minutes ago, Gershy13 said:

Hahahahhah no it's fine I get it lol...

Yup that's fine...

I'm probably going to Velcro or something the PSU to the amp... need to find a way to do it.. not sure it will hold Velcro . (Its carpeted) 

And as for the voltage, should I set it to 13.8v? The manual of the amp says 200w @ 13.8v

If the amp says 13.8V, then yea, set it to 13.8V

As for your securing the PSU to the speaker issue... screws?

That's what I did with my old car amp, just screwed it to the back of the speaker unit.

 

Just realised you said securing it to the amp, not the speaker, lol...

Erm... super strong 3M double sided tape... or super strong velcro as you suggest.

Need a mechanical engineer for that one, and unfortunately I'm an electronic one, hahaha.

[Gershy13]

3 minutes ago, rhyseyness said:

If the amp says 13.8V, then yea, set it to 13.8V

As for your securing the PSU to the speaker issue... screws?

That's what I did with my old car amp, just screwed it to the back of the speaker unit.

 

Just realised you said securing it to the amp, not the speaker, lol...

Erm... super strong 3M double sided tape... or super strong velcro as you suggest.

Need a mechanical engineer for that one, and unfortunately I'm an electronic one, hahaha.

Alright thanks... haha nice one! My brother is graduating this month and he's an electrical engineer lol

Screwing it to the sub is a shout... not sure if the PSU has mounting holes tho....

[Gershy13]

25 minutes ago, rhyseyness said:

If the amp says 13.8V, then yea, set it to 13.8V

As for your securing the PSU to the speaker issue... screws?

That's what I did with my old car amp, just screwed it to the back of the speaker unit.

 

Just realised you said securing it to the amp, not the speaker, lol...

Erm... super strong 3M double sided tape... or super strong velcro as you suggest.

Need a mechanical engineer for that one, and unfortunately I'm an electronic one, hahaha.

yeah it doesnt have screw holes to mount it... i would have to make some sort of bracket... im not sure if velcro will stick to the carpety surface...

[straight_stewie]

On 7/4/2016 at 6:00 AM, Gershy13 said:

 

So i want to connect up my car sub (with amp) to stuff around my house.. currently i have it running using a old 150w computer psu... but when it goes past a certain volume, it stops working (150w probably isnt enough...) So im trying to decide if i should get one of these

 

Well, you need to first figure out how much wattage and amperage you need to supply your amplifier with. To do this, you need the peak wattage at the resistance you are wiring your sub at, then you need to know the Amp's efficiency. Simply multiply the peak by the decimal efficiency (you will have to convert from a percent to a decimal). Then add the result of that onto your peak. You end up with the equation: peak * efficiency = y. powerNeeded = peak + y. 

Then you can find any 12 volt power supply that provides atleast that much peak wattage. You may also want to do the above calculation to be sure that the power supply you are getting can supply the needed RMS wattage. (RMS is essentially an average of what the amplifier will use, while peak is the peak wattage that the amplifier will need). If you get a PC powersupply, follow the following steps:

1. Make sure that the 12 volt rail(s) can supply enough power to run the amp (this number will be LOWER than the total wattage of the power supply). If necessary, you can connect your 12 volt rails in parallel with one another. Be warned, if you connect them in series and then complete the circuit, your power supply (and quite possibly your amp) will be ruined: Do not blame me for any damage to your equipment that occurs because of this. Do your own research and testing.
2. If you hold the 24 pin connector with the latch facing upwards, you need to take the 7th and 8th wires from the left, and connect them to each other. This will allow your powersupply to turn on. You may wish to use a switch here instead of hardwiring them so that you can turn the powersupply on and off without having to use the switch in the back.
3. Connect your PSU's 12 volt rail(s) to a fuse large enough to handle the setup. Connect the output of the fuse to the power input of your amp.
4. Connect the ground of your amp to the ground on the computer Power Supply. Try to keep the total length of the ground, including all wire that is part of the powersupply, as short as possible.
5. Hook everything else up exactly as you normally would.

[Gershy13]

24 minutes ago, straight_stewie said:

Well, you need to first figure out how much wattage and amperage you need to supply your amplifier with. To do this, you need the peak wattage at the resistance you are wiring your sub at, then you need to know the Amp's efficiency. Simply multiply the peak by the decimal efficiency (you will have to convert from a percent to a decimal). Then add the result of that onto your peak. You end up with the equation: peak * efficiency = y. powerNeeded = peak + y. 

Then you can find any 12 volt power supply that provides atleast that much peak wattage. You may also want to do the above calculation to be sure that the power supply you are getting can supply the needed RMS wattage. (RMS is essentially an average of what the amplifier will use, while peak is the peak wattage that the amplifier will need). If you get a PC powersupply, follow the following steps:

1. Make sure that the 12 volt rail(s) can supply enough power to run the amp (this number will be LOWER than the total wattage of the power supply). If necessary, you can connect your 12 volt rails in parallel with one another. Be warned, if you connect them in series and then complete the circuit, your power supply (and quite possibly your amp) will be ruined: Do not blame me for any damage to your equipment that occurs because of this. Do your own research and testing.
2. If you hold the 24 pin connector with the latch facing upwards, you need to take the 7th and 8th wires from the left, and connect them to each other. This will allow your powersupply to turn on. You may wish to use a switch here instead of hardwiring them so that you can turn the powersupply on and off without having to use the switch in the back.
3. Connect your PSU's 12 volt rail(s) to a fuse large enough to handle the setup. Connect the output of the fuse to the power input of your amp.
4. Connect the ground of your amp to the ground on the computer Power Supply. Try to keep the total length of the ground, including all wire that is part of the powersupply, as short as possible.
5. Hook everything else up exactly as you normally would.

Thanks, but as you can see by the previous posts, I have figured it out and am planninng to buy a power supply, so thanks, but shudda checked the posts first...

[rhyseyness]

On 7/8/2016 at 1:25 PM, Gershy13 said:

yeah it doesnt have screw holes to mount it... i would have to make some sort of bracket... im not sure if velcro will stick to the carpety surface...

Hmmmm... Only way you'd know is by trying it out I guess

[Gershy13]

9 hours ago, rhyseyness said:

Hmmmm... Only way you'd know is by trying it out I guess

yeah ill try and find if we have any velcro around the house and give it a go... The power supply should be coming in a few hours! Thanks Amazon Prime Evening Delivery!!!

[Gershy13]

On 7/11/2016 at 8:08 AM, rhyseyness said:

Hmmmm... Only way you'd know is by trying it out I guess

so velcro doesnt work, but on the plus side the psu works perfectly! Im getting so much volume! Just need to find a way to mount it... its currently sitting on top of the sub.

thinking of getting some velcro and screwing/nailing it to the sub...

[rhyseyness]

On 7/15/2016 at 4:14 PM, Gershy13 said:

so velcro doesnt work, but on the plus side the psu works perfectly! Im getting so much volume! Just need to find a way to mount it... its currently sitting on top of the sub.

thinking of getting some velcro and screwing/nailing it to the sub...

Glad to hear it works!

Velcro screwed/nailed to the sub sounds like a good plan

[Gershy13]

On 7/18/2016 at 8:15 AM, rhyseyness said:

Glad to hear it works!

Velcro screwed/nailed to the sub sounds like a good plan

yeah ill have to try it.

It sounds awesome aswell! I used it with 2 monitoring wedges, and its awesome!

[rhyseyness]

1 hour ago, Gershy13 said:

yeah ill have to try it.

It sounds awesome aswell! I used it with 2 monitoring wedges, and its awesome!

Excellent news!!