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Discussion Starter #1 (Edited)
I will be installing two amplifiers:

1. MB Quart REF4.80 rated for 4x80watts into 4 ohms and 4x160watts into 2ohms. Fuse rating: 2x35amps. This amplifier will power a set of 4ohm tweeters and mids (Hybrid Imagine) running active.

2. MB Quart ONX1.1500D rated for 1500watts RMS power @1ohm, 1000watts RMS @2ohms, 500watts RMS @4ohms. Fuse rating: 2x70amps. This amplifier will power Infinity Kappa 120.9w subwoofer configured for 4ohm load (sub rating: 350watts RMS). Down the road there could a subwoofer upgrade.. though somewhat unlikely.

Alternator rating: 130amps
Big 3: TBD

As you can see, both amplifiers will be used way below their maximum capacity. I was going to buy a 5-channel Alpine or something but then I picked up both of MB Quarts because I like their compact size, and total price was less than a less powerful 5-channel.. so why not.

I have questions about fuse rating at the battery, distribution block, wire gauge, etc.

1. I know the usual rules of fusing at the battery, but given that I will be using both amplifiers way below their maximum power output potential and that car's amplifier will not provide more than 130amps of current, is it really necessary to have a 210amp fuse at the battery? What would you recommend?

2. Right now I am running a 20ft long 4awg power wire from the battery to my trunk. Is this wire safe to use in my situation or should I upgrade to lower gauge?

3. Is it necessary to fuse the power wires between the distribution block and the amplifier? Is it ok to run 4awg wire from distribution block to the amplifiers?

4. What wire gauge I should use to run from the ONX1 amplifier to my subwoofer?

5. For the big three, what gauge of wire do you recommend?
 

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150 at the bat is all you need

Knukonceptz4 gauge is perfect for your situation

12 gauge for subs is fine
 

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there are some cheap cadence 0 gauge kits, or buy the wire in balk on ebay. run the 4 gauge between the distro's and amps.

for the big three the best bet would be to run 0 gauge. you might be able to get away with using left over 4 gauge for your big three instead of buying more 0 gauge.

Amazon.com: cadence 0 gauge: Electronics
 

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^ you know that isn't 0 gauge right lol, good joke!
 

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As far as the fuse at the battery, fuse it for the rating of the cable, Not the amps. Check the Manufacturer's current rating on the cable and fuse below that value.

I'd use solid copper welding cable in the engine bay, and back to your distribution block. Then yet can switch to a more commercial brand for appearance, if that's of concern.
Knuconcepts has good quality cable and connections for inside the vehicle. THe welding cable would save you a little money for the long runs.
 

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I'd do solid copper all the way through regardless including speakerwire. Copper can carry more current than cca and you don't have to worry about corrosion or set screws getting loose which can cause a fire hazard. For fuses fuse the main wire to 125a, your sub amp to 80a with a 4g run, and the 4ch only needs a 50a fuse for the load you're giving it. For your sub and all speakers 16g is plenty right now but if you go down to 2 or 1 ohm on your sub 12g will likely be needed. I personally run 16g for all 5 speakers in my install.
 

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Discussion Starter #7
I have more information on what I have installed now.

It has been a while since I installed my current power wire, but I finally found out what it is as well as the fuse rating.

The kit that I installed is StreetWires ZN5K-04. It comes with 18 ft. of 4 AWG power cable and a fuse holder with a 150amp fuse. I have heard several people recommend me to spec the fuse rating for the wire, including recommendation of 125-130amp fuse for the wire of this thickness and length. However, if the manufacturer includes a 150amp fuse, then the wire is perhaps good for 150 amps of current or so? It seems to me I could leave my amp wiring as is and add a distribution block to the amps.

The kit description says:

* Designed specifically for car audio systems up to 1000 watts
* Made from 100% oxygen-free copper for a pure uninterrupted transfer of power
* True-to-Gauge cables/wires meet or exceed the industry standard of copper required for the gauge size
* CEA-2015 Compliant
 

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Sounds good man. I tend to do my main run at 0awg though... I try to account for future upgrades, and don't want to do it more than once. Lol
As mentioned above, but I forgot to mention... Make sure your using ofc of true gauge. And as your last post states, you are.:)
 

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Discussion Starter #9
I try to account for future upgrades, and don't want to do it more than once. Lol
Heh.. Sounds like the voice of experience.

I am on the fence about running thicker power cable.. based on what I know, for the load that I will be driving with my amp, the current power cable and fuses should be fine... but what if I upgrade..

Having said that, I think I will not be upgrading anything any time soon. I can see myself in about a year putting in a DSP like JBL-MS8 and rear fill speakers running from JBLs built-in amp, but not much else.
 

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Heh.. Sounds like the voice of experience.

I am on the fence about running thicker power cable.. based on what I know, for the load that I will be driving with my amp, the current power cable and fuses should be fine... but what if I upgrade..

Having said that, I think I will not be upgrading anything any time soon. I can see myself in about a year putting in a DSP like JBL-MS8 and rear fill speakers running from JBLs built-in amp, but not much else.
Lol well you know yourself and what you have planned... If it's what you need, your golden.
Now me, I know myself... And I better be prepared for my constant indecision. Lol
In the past year, I've had old school ab's x3...newer ab's x2 +d...4x older d's... And will prob change to 3x new class d's! Lol
 

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Have you already bought the amps? I own a MBQ Q4.150 and bought an ONX1.1500D for an install that I helped with and both are total crap. With the Q4.150, it runs at a million degrees and turns off all the time in the summer, has a super noisy fan, and is known for killing tweeters in an active setup. With the ONX, it just doesn't seem to have the output that my old Planet Audio P1250D does. Like... significant difference with the same speakers in the same box. I thus conclude that Maxxsonics amps are garbage and will never buy or recommend them again.
 

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Discussion Starter #12 (Edited)
Have you already bought the amps? I own a MBQ Q4.150 and bought an ONX1.1500D for an install that I helped with and both are total crap. With the Q4.150, it runs at a million degrees and turns off all the time in the summer, has a super noisy fan, and is known for killing tweeters in an active setup. With the ONX, it just doesn't seem to have the output that my old Planet Audio P1250D does. Like... significant difference with the same speakers in the same box. I thus conclude that Maxxsonics amps are garbage and will never buy or recommend them again.
In my opinion, you can't really say anything about ONX1 unless you have measured its output. Comparing it to another unmeasured amp is not good enough. Perhaps it's just your old Planet Audio is underrated? That's not unheard of older amplifiers, many were also rated at lower voltage. ONX1 is probably rated at 14.4V and based on what I have heard, it does the rated power. The cars could have different wiring, alternators, etc.

Regarding the REF4 amplifier, the reason I got interested in it is because a Russian car audio web site recently did a comparison of budget 4-channel amplifiers and took measurements. This was their top pick. Not only it does a lot more than rated power (it did 110/180watts instead of 80/160), it also measured well in "SQ" measurements like THD, channel separation, etc. The way I see it, this amp is a hidden gem. To put it in perspective, the same web site was not so impressed with a 5-channel MB Quart ONX in a different review (it did ok, just not greatly).

Yes, there is a bit of gamble there, but I paid $120 for the REF4 and $140 for ONX1, both new and shipped for that price, and it seems like in both cases I roughly know what I am getting, and it seems like a good value. Both have 1 year warranty, so I hope if I get a bad apple, I might swap it for a better amplifier. Oh another thing.. I don't have a place to install my mono block amplifier in any place other than on the back of subwoofer box, which is not optimal. However, should my mono amplifier be destroyed from sub box vibrations, I would really prefer if it was a $140 ONX1 amplifier instead of a $300 kicker or alpine..

I don't know anything about amplifier design, but class A/B amplifiers run HOT. Point. I have heard of people reporting all kinds of amplifiers shutting down in the summer, from higher quality BA amps all the way through cheap Jensen amps. You need a huge heatsink and forced cooling if you expect the amplifier to put out a lot of power. For this reason, I will never consider class A/B power to run a subwoofer, but for normal speakers or active front stage which needs even less power, why not?
 

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I'm not pulling much power from it - it can smoke my fronts easily and 2 channels are used only for tweeters which barely need any power. It's way overpowered for what I need. It does need larger rail voltages than smaller amps just to be able to have the output potential, but I don't think it is very efficient even for an AB amp. It alone, even at only moderate output, was pretty bad on my stock charging system... and my stock system had a 145A alternator (now a DC Power 270XP). And that was without a sub. With the Q4 and Planet Audio amps, I have no issues with the 270A alt, but I don't think I should have had problems with just the Q4.

Good luck with the amps since you already bought them. I hope you don't have the problems I did, but I personally won't ever buy a Maxxsonics amp again.
 

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I don't know anything about amplifier design, but class A/B amplifiers run HOT. Point. I have heard of people reporting all kinds of amplifiers shutting down in the summer, from higher quality BA amps all the way through cheap Jensen amps. You need a huge heatsink and forced cooling if you expect the amplifier to put out a lot of power. For this reason, I will never consider class A/B power to run a subwoofer, but for normal speakers or active front stage which needs even less power, why not?
not true at all. plenty of class A/B designs that dont blister your fingers. my old hifonics amps got barely warm run flat out for hours.
 

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Discussion Starter #15
not true at all. plenty of class A/B designs that dont blister your fingers. my old hifonics amps got barely warm run flat out for hours.
Well it seems like there is a difference between old and new.. a lot of current amps are not meant to run efficiently, because they're skewed to run in 2ohm mode. For two or four channel amp to power a subwoofer, channels have to be bridged and the amp ends up running in its least efficient mode. A/B subwoofer section is also common on 5-channel amplifiers.. but they put so little power into 4 ohms that again it's pretty much given that the sub channel will be running at 2ohms.. meaning less efficiency.
 
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