wiring a D4 sub to a 2ohm stable amp

ok thanks. So basically when the guy installed my equipment, he wired it in 8ohm, and what everyone is telling me, regarding wiring it in 2ohm is correct.

Now comes the amp, the amp is not 2 ohm stable in bridged mode, to my understanding. So, how should I run my amp?. Set the selector to "mono", and run out of one channel?.

Am I going to hear that noticable of a difference?, because myself being a newbie.. I see running it at 2ohm would drop the wattage. So, that leaves me alittle confused.

nyguy4u wrote:

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 I am into SPL, and I want to get every bit out of the amp as I can.

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That second diagram, at 8 ohms per sub/amp, is correct.  But  your original selection of equipment is where you went wrong if you want to wring the maximum out of everything.  You should change either the subs or the amps...

...if you change the subs, use the D2 model instead of the D4's.  You can then wire them to 4 ohms each.

...if you change the amps, use mono amps instead of two channel amps.  With your current subs, the final 2 ohms loads will indeed work if the amps were mono.

With the change will come twice (or more) draw upon your car's electrical system, so an upgrade in alternator, wiring and batteries will most likely be necessary.  And, sound damping of the vehicle will have to be increased.  So, in reality, the trade-out will cost you.

nyguy4u wrote:

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I see running it at 2ohm would drop the wattage. So, that leaves me alittle confused.

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You have it backwards.  A lower impedance load on the amp will cause the amp to produce higher output.

nyguy4u wrote:

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Am I going to hear that noticable of a difference?

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The difference will be heard when your amp dies from running it at 2ohms.

Yeah, I know I should either have mono amps, or D2's.. but right now, my financial situation won't allow me to do that.

I'm not sure how running my amps at 2ohms would make them "die", if the amp is 2 ohm stable. Please explain?.

So, until I buy different amps and/or subs.. I should just keep my setup the way it is?. Wired in 8ohm. And, my installer was incorrect then?.

I'd like to keep these subs, so if I did do something.. i'd buy different amps. I like an amp to a sub setup, so i'd buy 3 mono amps. With my subs, what's the highest wattage mono amp i'd be able to go?. 2ohm stable of course :)

I agree with keeping the subs and changing amps, the main reason being that a mono class D amp is much more efficient in powering subs than a two channel class A/B amp.  So the load on your car's electrical system when changing won't be such a drastic difference.

Yes, you will have to keep the setup the way it is.  To explain why it doesn't make sense to you that the amp is 2 ohm stable but you can't bridge a 2 ohm load onto it:  the amp is 2 ohm stable per channel.  Bridging is across both channels, and the load is split between the two, making each channel get a load of 1 ohm.  The amp will shut down or burn up in that scenario.

Your subs are rated at 500 watts RMS.  Right now they receive about 230 watts each.  The mono amps you eventually switch to should be rated at 500 watts RMS output into a 2 ohm load. 

And...when you switch amps you will also have the opportunity to change to a single amp to power the three subs, which will result in less load on the alternator.  You could shop for a mono amp capable of 2000 watts into a combined 2.67 ohm load.  (..and save the extra cost of buying three amps...)

Here's a good buy and a good example:  https://www.cardomain.com/item/JBLBPX22001Z

With the use of just one amp, you can sell the line driver and get it out of the signal path.

nyguy4u wrote:

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I'm not sure how running my amps at 2ohms would make them "die", if the amp is 2 ohm stable. Please explain?.

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ok, I got what you guys are saying. Thanks alot.

So, i'll wire the subs to 2ohm, and get a 2ohm stable mono class D amp. I know one amp would be better to power all 3 of my subs, and less drain on my system, but I have 3 amps, more for look in a fiberglass setup. It's a show car, but it's also a cruising car too. I already have a Optima Yellow top, and a HO Alt, so my electrical system is pretty good. So, i'll stick with 3 amps for now.

As far as numbers now, what should I be looking for as far as Mono amps?. Not really brand wise, but #'s wise. As stevdart stated, my subs are rated at 500rms, and peak.. well, I don't know.. because JL Audio's website doesn't even list a peak #. So, when looking at amps, I should really only be concerened at the ratings for 2ohm, and rms, correct?. I see some amps, that are rated for 500rms, but a peak much higher then 500.. so that is ok, right?. I was looking at an Alpine at 1,000 watts RMS x 1 at 2 ohms. I was also looking at a MB Quart at 657 watts RMS x 1 at 2 ohms, and an Infinity at 657 watts RMS x 1 at 2 ohms. Which one would I wanna get?. Would I want to stay with the MB and Infinity because it's closer to 500?, or are even those to high of a RMS to power my sub?.. and should I find an amp rated for 500rms at 2ohm, and lower?.

We're only concerned with RMS output and continuous power handling.  Words like "peak" and "max" have no value here.  Anything higher than 500 watts at 2 ohms is too high, unless you are meticulous about measuring output and making sure the amp is not overpowering the sub.  Safest way to go is to use a good brand that makes 500 watts. In fact, that nice JBL I pointed out would be too much power unless you tamed it.   This Memphis amp is spec'd as you will want and would make a fine addition to a show car...highly recommended.