Googling my questions does not give me clear answers...probably a 3 min answer from someone with skills...


Kube1989

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Hi-
I'm new....my son has a 78 Cordoba with a new (but cheap) head unit. Speakers are original and floating ground system and truly sounds awful- so I want to replace speakers.
Front has 3.5" on dash, Rear is 6 x 9s. want to add 5ch amp and sub in trunk and allow for EQ in future.

Looking at:
• Planet Audio AC1800.5 5 Channel Car Amplifier - 1800 Watts, Full Range, Class A/B, 2-4 Ohm Stable, Mosfet Power Supply, Bridgeable
(
Power - 300 watts max x 4 @2-Ohms plus 5th channel 600 watts max x 1 @2-Ohms, 150 watts max x 4 @4-Ohms
plus 5th channel 300 watts max x 1 @-4-Ohms, 600 watts max x 2 bridged @4 Ohms)

• a pair of 4 ohm, 200RMS/400 max 6x9s for rear
• a pair of 4 ohm, 120RMS/300 max 3.5 for front
• 4 ohm Alpine SWT-12S4 1500W Max (300W RMS) Single 12" Sealed Subwoofer Tube

I planned on taking the single pair of RCA out of head and splitting them so I get 4 sends to amp. (also allowing for easy EQ addition later)
Using the amp's 5th channel selector to take MIX of Ch1-4 for sub input.

Questions are:
1. Are those speaker ratings OK for that amp? (I have seen too much conflicting info to understand whether spkr or amp need to have more wattage)

2. I understand the power for amp should not run with the signal send from head to amp- but can the sends run with the spkr returns to front?
I've only got 2 sides of the car for running wires...how would a professional split them up?

3. Does the amp magically know what ohmage the spkrs are? I do not see a selector switch on amp for 2 vs 4 ohms...
I'm guessing it can sense the impedance and pushes wattage accordingly?

If anyone has suggestions of what would work better with the amp or vice-versa- I'm all ears...
(BTW... his budget is under $500 for total project)

I appreciate any and all help, in advance! Thanks
 
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hispls

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Planet Audio is a very low quality brand and every piece of equipment you listed is lying about power output/handling which is a bad start coming out the gate.

Cheapest thing I see at a glance for a reliable 5 channel amp is about 350$ but there may be some sales somewhere or a better option. I'd say you should be looking for 50x4 + 300X1 rating which is adequate and will likely mean you have a product that isn't trying to lie to you. Ditto with speakers. There's not a set of coaxials out there that'll really withstand 200W and I'd avoid any company who would claim otherwise on general principal. That said 50-70w honestly rated coaxials would do fine for you and Alpine, Kicker, JBL/Infinity, and other trustworthy brands should all have comparable entry level offerings for you.

A high end 5 or 6 channel amp would have switch to internally sum signal from only one RCA pair in but you're probably going to run Y splitters up by the amp. Keep RCA away from any power cables is good practice, speaker level outputs shouldn't matter but normally I'd do power and speaker stuff down along whichever side the battery is on and RCA in the center or up high if possible.
 

Popwarhomie

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jt4x4

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For question #3: the amp doesn't need to know the speaker impedance. The amp creates an output voltage, and current and power follow suit based on impedance. The math is up to you.
 
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Kube1989

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Well I went ahead and purchased the items you suggested. My question is wiring the sub. It's got dual voice coils. Dual 2 ohm. None of the paperwork shows how to wire that. Do I have to jump from terminal to terminal or just use one set of them or what? Thanks for your help :)
 

Popwarhomie

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1.jpg
 
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Coolhand20th

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I would wire it to a 1ohm and according to the NVX information on Amazon it is capable of 1ohm stability. Just adjust the gains correctly. But as pop pointed out 4ohm is ok on that as well since it does 350 and the sub is 350 rms.




26521
 

Kube1989

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I have seen that diagram however the amplifier is not forum it's too home. Or am I running the dual 2 to accept the 4 ohm from amp?
I would wire it to a 1ohm and according to the NVX information on Amazon it is capable of 1ohm stability. Just adjust the gains correctly. But as pop pointed out 4ohm is ok on that as well since it does 350 and the sub is 350 rms.




View attachment 26521
Thanks everyone I appreciate it :)
 

nauc

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id run component speakers in the front doors, sub and amp/s

forget rears. save that money for better stuff

for subs i like Fi. amps Taramps. comps Image Dynamics

fwiw, im pickin up this beauty for home theater soon 😁

 

LsGuy

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I have seen that diagram however the amplifier is not forum it's too home. Or am I running the dual 2 to accept the 4 ohm from amp?

Thanks everyone I appreciate it :)
It took me so long to figure out what you were trying to ask here lol.

Your amp doesn't determine the impedance (2 ohm vs 4 ohm), your subwoofer does. Your woofer has 2 two ohm voice coils. Wiring them the method shown in the diagram pop showed will create four ohms of resistance resulting in the subwoofer receiving 350 watts RMS from the amp. This is wiring in series. If you wired it in parallel your subwoofer impedance would be one ohm. Your amplifier does state one ohm stable, but doesn't state power output at one ohm that I saw. Regulardless, one ohm wiring would likely result in over double the rated power of that subwoofer.
 

Coolhand20th

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The information on Sonicelectronix says 350 rms and 700 max on the subwoofer. But also says 600x1 at 2ohms on the amplifier. So yeah 2ohms would be perfect for it. Says 1ohm stable on Amazon but not on Sonicelectronix so idk if I would now trust the Amazon information yet they "supposedly" get it from NVX. Amazon has been wrong before on this stuff. I think I would do the 2ohms after going through all that information on Sonics site since they were the ones who had them built for them as a in-house Car Audio company.


 

Popwarhomie

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I would wire it to a 1ohm and according to the NVX information on Amazon it is capable of 1ohm stability.
I was wondering why I recommended a D2 ohm subwoofer for that amp. I forgot it is 1 ohm stable.
 
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Popwarhomie

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Popwarhomie

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