Amp/sub question (spec help please)

fluxcapacitor11 · September 23, 2017

I need some help from the electronic gurus. I have a monoblock amp, runs 1500w @ 2 ohms, 750w @ 4ohms. I have one 4 ohm sub hooked up. The sub came mounted in a box, and I would like to add an identical one on the other side of the truck.

To do this properly, how would I add the speaker? Run a second set of speaker wire from the single channel on the amp? Connect the 2 speakers to each other and run a common wire to the amp? Direct wire one to the amp, then "jump" to the second speaker from the first?

Sorry for my ignorance in this. Just don't want to burn up the amp or the voice coils. Thanks!

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Maxsuperdog · September 23, 2017

Do a search on Crutchfields site and you can find the proper wiring diagram.

fluxcapacitor11 · September 23, 2017

I did. But I'm still not sure about it. I don't want to run the amp at 2 ohms and every diagram I saw, adding a speaker did that. I'm not great at this stuff, so just want to be sure I don't slam 1500 watts to a 600w speaker

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Ichie123 · September 24, 2017

Not enough information here to make a fair assessment. You don't want the amp to run at 2ohms. Why? If the sub is already being pushed the full 750 for one, the added sub would need another 750 watts additional in order to not underpower both subs. Underpowering can fry a sub just much as overpowering.

The question is are you wanting just to run at 4 ohms for the SQ? If so you need to buy an amp that will run 1500watts at 4ohms.

Or are you just trying to match the power the subs need? In thta case you would need to wire down to 2 ohms. But of course this all revolves around is your subwoofer a dual voice coil (DVC) or is it a single voice coil (SVC)

fluxcapacitor11 · September 24, 2017

So the speaker I have and the one I want to add are both 4 ohm, 600w max. I'm just trying to not blow them.

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fluxcapacitor11 · September 24, 2017

They are the cheap pioneer down fires. I would assume they are SVC.

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Ichie123 · September 24, 2017

Alright so you're pushing 750watts to a MAX 600 watt sub? You need to know the RMS of a sub and match that up to your amp. Otherwise you're just over powering it right now.

So assuming they are SVC there's no way to keep 4 ohms. It will be forced to go down to 2 ohms. Now you said the amp does 1500 at 2 ohms. The best solution is to find an amp that will put out the right wattage at 2 ohms. Otherwise you're going to blow them pretty fast.

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fluxcapacitor11 · September 24, 2017

Thanks. I think that's where I screwed up with this. RMS of the amp is 563w at 4ohm. 1125w @ 2ohm. Speaker is only listed as 4ohm, now rms listed, but nominal is only 150w. Guess I'm grossly over powered. I just read 600w speaker and amp had 563w rms.

Keep in mind these pioneers come in a sealed box, and they are very tight. So I don't want to risk losing the seal by popping the speaker out to check the coils. Especially if I am about to return it because it's just too weak to handle the amp.

My whole goal of the thread was to see if even hooking a second identical speaker to the amp was possible without damage.

Thanks for all the help.

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HagiborChayil · September 27, 2017

Late response, I know. Yes, with how ohms laws work the second sub when wired in parallel will receive the same amount of power that the first has.

Max is a pretty number to get someone to buy a product.

RMS (root mean squared) is an actual mathematical formula to show the continuous power that can be run to a product. Pioneer calls continuous/ RMS nominal.

Worst case is wire them in series to 8 ohm if you grossly over powered them. Or tune very well.

Giving model numbers can always help for us to double check for ya. Hope it all works great since I'm so late in my response.

fluxcapacitor11 · September 28, 2017

Thanks for the response! I've done some more research on my equipment. The speaker is DVC wired in the box to 4ohm. I also dig deeper into reviews of my amp where people with more equipment and knowledge than me tested the amp and got about 120 watts out of it.

So with all that. I should be able to lower the output on my amp (tune well) and "daisy chain" 2 Identical speakers. This would keep the amp 4 ohm to match the speakers and not over power them. The second sub will be in tomorrow, so we'll see!!!

Amp: BOSS Audio AR1500M Armor 1500 Watt, 2/4 Ohm Stable Class A/B, Monoblock, Mosfet Car Amplifier

Speakers: Pioneer TS-SWX2002 8" Shallow-Mount Pre-Loaded Enclosure

I know it's not a killer system. But it's affordable and with one speaker it is about the bass of the bose system. 2 should be all I can handle. I have one in the center console now, and will put the second under the back seat.

Thanks again to everyone that helped!

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HagiborChayil · September 28, 2017

Ok with those subs if yuou wire them In parallel you will get 2 ohms and in series you will get 8 ohms.

Boss is extremely well known for not pushing anywhere close to the numbers they claim. It has a 30 amp fuse on it meaning that if it were 100% efficient with its power (boss wont be, and neither will class A/B) the laws of science as noted by Ohm say that watts = volts × amps. Voltage from the battery when the vehicle is pin should be 14.4 roughly so we will assume that.

So 30 amps × 14.4 volts = 432 watts of output at best... So I would say it would be safe to run those in parallel.

Lastly remember gain is not volume. No reason for that gain to be over halfway under most circumstances

fluxcapacitor11 · September 28, 2017

Got the second one in. Definitely adds to the system. Still not the 12 I was used to in my last truck, but I just need to realize with where I want these speakers placed, this is what I have!

Thanks again for all the help.

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