IDMAX12 - need 4ohm vs 2ohm load help

[Gauntlet 5,000+ posts]

I recently got a new job making nearly twice as much as I previously did, so I decided its time to blow some cash and get some serious car audio equipment.

In my 92 oldsmobile cutlass ciera, I already have a Pioneer DEHP-8400MP head unit, Infinity Kappa 6x9's in my rear deck and 6x8's in my doors, and cerwin vega 3 1/2's in my dash and tweeters mounted near my overhead visors. I have a Power Acoustik Sapphire SP4X-800 powering the infinitys, and my HU is powering the cerwin vega dash speakers and tweeters.

I plan on buying 2 Image Dynamics IDMAX12 subwoofers along with an Earthquake PHD2 amp to power them (http://www.etronics.com/product.asp?stk_code=earphd2). The question is, the amp specs say it can push 2000x1 at 4ohms and 2000x1 at 2 ohms, so should I purchase the IDMAX12D2 or IDMAX12D4? Also, whatever the answer is, why is 4ohms better than 2 ohms or why is 2 ohms better than 4 ohms?

Anyone have recommendations on what amp wiring kit to get/what gauge wire to use?

Oh, and if anyone has any recommendations on what type of box to put the subs in, i.e sealed or ported etc, thatd be greatly appreciated too.

Thanks for all your help!

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[adamS 10+ year member]

you are going to want to get 2 of the id 4 ohm subs, the subs are duel 4 ohm, so if you wire the voice coils in series, and then wire the subs in parellel, and it will produce a 2 ohm load on your amp.

And it isn't a matter of 2 ohms being better then 4 ohms or not, its just what the subs will produce. A lot of times, when you cut the ohms in half, alot of amps will put out more power, some will just put out the same (like your amp) to give you more flexiblilty when you wire your system.

IDMAX's sound great in sealed encloseres, but dont listen to people that say sealed gives you better SQ, a properly built ported box will give you the same SQ with more SPL, it just depends on how much space you have to give up in your trunk, or how much you are willing to give up.

 

[Gauntlet 5,000+ posts]

thanks for the help, but i have a few more questions.

1) first, youll have to explain to me how to wire the voice coils in series and the subs in parallel. does that mean to wire the left and right channels of each individual sub together, then wire those left and right channels together producing one left and one right channel total for the 2 subs, then hook it up to the amp? or am i completely off here?

2) second, why would i buy the 4ohm IDMAX12's when im just going to wire them down to 2 ohms? wouldnt it be easier to just buy the 2ohm version and not have to do all that work?

thanks for all your help, its much appreciated

 

[Alaxan 5,000+ posts]

Originally posted by Gauntlet thanks for the help, but i have a few more questions.

 

1) first, youll have to explain to me how to wire the voice coils in series and the subs in parallel. does that mean to wire the left and right channels of each individual sub together, then wire those left and right channels together producing one left and one right channel total for the 2 subs, then hook it up to the amp? or am i completely off here?

 

2) second, why would i buy the 4ohm IDMAX12's when im just going to wire them down to 2 ohms? wouldnt it be easier to just buy the 2ohm version and not have to do all that work?

 

thanks for all your help, its much appreciated

Dual voice coils produce a slightly higher output and if you purchased 2ohm dual voice coils you would never be able to allow your amp to see a 2 ohm load. By running a lower load to your amp you allow it to push more freely and thus get a power increase. This is the reason it would be best to get a dual voice coil 2ohm sub. Wiring in series means basically you will go from positive to negative from one coil to the other on each sub. You will then take a lead from the positive on one coil on one sub and run it to a positive on another coil on the other sub and then to the amp's positive lead. From the negative on the opposite coil on each sub you will connect and send to the amps negative lead.

 

[Gauntlet 5,000+ posts]

ok, theres a change of plans. My buddy works at best buy and can get me 2 brand new JBL 1200.1 amps for $400, which pushes 1200x1 at 2 ohms. After hearing about how much current the Earthquake PHD2 uses, and the fact that the JBLs are 100 bucks cheaper, I decidided JBL is the way to go.

Now, let me try and get this installtion process correct. I plan on having a JBL1200.1 power each 4ohm IDMAX12D4 (I only plan to run the amps at 75% power). This is my plan, let me know if I am correct or if there is something I'm missing. The system is costing me well over $1500 - I can't afford to mess up and professional installation prices are freaking ridiculous.

The subs are 4ohms, so I will need to wire them in series to bring them down to 2 ohms. Each sub has 2 coils, lets call them coil A and coil B. I take a pos from coil A and connect it to the pos lead on the amp. I connect the neg from coil A to the pos on coil B. Then, I connect the neg from coil B to the neg lead on the amp. Then repeat the process for the other sub and amp. Is this correct, or am I completely missing the concept?

Also, this system is obviously going to be pushing a lot of power. I currently have an Optima D34 (red top) battery which has 980 cranking amps. Would it be better to get a second battery to power the system, or would a 1 farad capacitor suffice?

Thanks for all your help, you guys are saving me a bundle of $$!!

 

[mrray13 10+ year member]

if your going to buy the two amps and push each sub with one and the amps are two ohm stable your going to need the dvc4 subs, wire the vc in parallel( +to+ and -to-) and then parallel to the amp. this will give you your 2ohm load per amp.

how's your altenator? that's what is going to keep it going as the car is running. IMO, your battery is big enuff and if your alt is a hi-po one(more than 110amps), then a 1farad cap, per amp, would suffice. of course a second battery,and necessary hardware, isn't a bad decision either. especially, if you got the $.

as to your wiring, 0 gauge running from your battery to distrubution block. from there 4 gauge to your amps should suffice. 12 gauge, minimum, to your subs, i would probably use 10 gauge there.

hope that helps......................

 

[Gauntlet 5,000+ posts]

---

if your going to buy the two amps and push each sub with one and the amps are two ohm stable your going to need the dvc4 subs, wire the vc in parallel( +to+ and -to-) and then parallel to the amp. this will give you your 2ohm load per amp.

---

My alternator is 120amps.

The JBL1200.1 is stable at 2 ohms and thats what i plan to run them at. So I should buy the 4ohm subs, wire the DVC in parallel, then parallel to to the amp to produce a 2ohm load? What would wiring the DVC in series and then parrallel to the amp do?

I'm just confused, because adamS told me to wire the DVC in series and parrallel to the amp to produce a 2 ohm load, but now youre telling me to wire the DVC in parallel then parallel to the amp to produce a 2 ohm load.

thanks

 

[Alaxan 5,000+ posts]

Originally posted by Gauntlet ---

if your going to buy the two amps and push each sub with one and the amps are two ohm stable your going to need the dvc4 subs, wire the vc in parallel( +to+ and -to-) and then parallel to the amp. this will give you your 2ohm load per amp.

---

 

My alternator is 120amps.

 

The JBL1200.1 is stable at 2 ohms and thats what i plan to run them at. So I should buy the 4ohm subs, wire the DVC in parallel, then parallel to to the amp to produce a 2ohm load? What would wiring the DVC in series and then parrallel to the amp do?

 

I'm just confused, because adamS told me to wire the DVC in series and parrallel to the amp to produce a 2 ohm load, but now youre telling me to wire the DVC in parallel then parallel to the amp to produce a 2 ohm load.

 

thanks

A 4ohm DVC load in parellel will provide a 2ohm load to the amp......if you are getting 2 amps like you said and running two subs like you said. Run one sub to one amp. Wire the voice coils in parallel.

 

[Gauntlet 5,000+ posts]

thanks a bunch you guys have been a big help