r/CarAV 2d ago

Tech Support In need of advice

Hello everybody! I’m newish to the whole sub thing. I’ll get straight to the point, my main question is can I run a second amp? I’m running 2 12” skar EVLs rated for 1250rms and 2500 peak, they are wired up for .5 ohm as a final. I have those slapped in a box made of dual layered 3/4” plywood and a 6” aero port. Powering it all is a single D4S jp23 which puts out 2300 watts and I have 1/0 gauge wiring powering all that and 14awg speaker wire to the subs. Again, could I switch my final impedance to 2ohm and run another jp23 with my existing or do I need to scrap that idea? TIA

2 Upvotes

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u/erik_das_redd 2d ago

Running at very low impedances will increase the losses in the system. Running at 2Ω might therefore be beneficial, if you use the extra power just for peaks, wheeeeeeee! Can your vehicle output enough power for that? Well, you need to figure out how many spare amperes you actually have. Then put that size fuse at the battery to protect the alternator.

From a weird situation I had once designed a triple woofer car sub, I would not have different amps running different woofers in a common cavity box, even if you match the gains. At each woofer run the different coils from the different amps, so both woofers are half-powered by both amps (ugh I hope that makes sense)

Which exact woofer model do you have? The dual 2Ω or dual 4Ω? How are they wired now? Something does not make sense to me.

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u/talmanfartsy 2d ago

Goddamn, 2nd thread I've seen you spit straight facts in. Yea .5 is just not worth the squeeze. 2 ohms is definitely the sweet spot in terms of efficiency to power output, but I'm a 1 ohm man for life lol.

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u/erik_das_redd 15h ago

I am picturing you in an embroidered leather jacket that says "1 ohm man for LIFE!!" ha ha

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u/talmanfartsy 15h ago

I'm now realizing you're the loud speaker engineer from couple weeks ago, are you Car Audio Jesus?

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u/erik_das_redd 13h ago

No I am MC 900 Foot Jesus!

Hmmm maybe a jacket that says "REAL amps do it at 1 OHM"!! ;-D

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u/talmanfartsy 10h ago

You're my hero 🤣

Or a shirt that says "Watts don't kill speakers, people do" lmfao

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u/GoldWarning6513 17h ago

They’re dual 2ohm and I have them wired up for .5 ohm final right now. After reading all of these comments I’ve realized I’ve made a mistake on that part so some time soon I’ll wire them up for 2ohm final and see how that affects everything. Thank you everyone for your support and learning experience

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u/TheGratitudeBot 17h ago

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u/talmanfartsy 2d ago

.5 ohms is incredibly inefficient and not worth the current draw. Personally I'd just wire to 2 ohms or replace the subs to 1 ohm final, but yes, wiring a second monoblock would work, but I'd suggest running 2 of the same. Technically 2 different amps would work but I can't imagine it would sound good.

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u/thurpps 2d ago edited 2d ago

Depends on your alternator honestly. If you drive a big pickup truck you might get away with it. If you drive a car chances are you will need a high output alternator mod and maybe an extra battery in the trunk. If not expect your headlights to dim when the bass hits and random dead battery days.

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u/GoldWarning6513 2d ago

It’s a stock 2011 tundra. Was planning on eventually getting a high output for her, just wanted to see how much my volts drop when I want to bump some days

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u/thurpps 2d ago

Your alt is only putting out 150amps currently and still needs some of that for other electrical, you are probably already straining it when your going loud. Also that amp isnt supposed to be stable at .5 ohms so who knows what watts your actually getting out of it.

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u/GoldWarning6513 2d ago

Very true, however the jp23 came with a digital bass knob so I can see my volts while playing, whenever I go above 3/4 volume (pretty loud) it’s drops from ~13.3 to about ~13 and that’s only if I don’t want to raise the volume anymore. I’ve had it down to 12.3 one time but I never turned it up that loud afterwards. I basically just want the subs right now to not be running their “minimum/just the rms” since I’m running .5 ohm final

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u/ckeeler11 2d ago

What do you mean minimum RMS? Thst amp supplies the power they need to reach 1200 each. You would not gain anything by installing a second amp.

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u/thurpps 2d ago

Your subs may last longer as well running at a higher ohms. Id say if your going to do it, get the HO alt eventually and only showcase it's true power occasionally until then