planning sound system upgrade, 03 g35

I'm new to the forum and have been spending a lot of time reading the threads here on the site. Anyway, based on the research I've done, here's my game plan for upgrading my OEM sound system.

Right now I've got a 2003 Infiniti G35 coupe with the Bose amplifier/OEM speakers. I replaced the HU with an Eclipse AVN5435 three years ago. It's been working great. But now I'd like to upgrade my sound system even more, bit-by-bit.

I've ordered a complete set of Infinity Kappa speakers to replace every OEM speaker in the car right now. I chose the Kappas largely because the OEM Bose amp runs at 2 ohms and I needed 2-ohm speakers to match up. In addition, I've heard them and like the way they sound. Anyway, here's what I ordered:

*Front doors: Infinity Kappa 60.9cs component speakers (w/ tweeter)
*Rear sides: Infinity Kappa 62.9i 6.5" speakers
*Rear deck: Infinity Kappa 692.9i 6"x9" 2-way speakers

For now I'll just utilize the OEM speaker wiring coming from the Eclipse HU. In the future, however, I'm going to want to get an amplifier and a subwoofer to round out the system.

As for the amplifier, I'm targeting the Alpine PDX-5 (5-channel). I plan to run my front Kappa component speakers of two of the channels (75wx2@2ohms). I'll also run my Kappa 6x9's off two more channels (75wx2@2ohms).

I can then run a sub (300wx1@4ohms) of the remaining channel. I was looking hard at the JL Audio Stealthbox (10" W1v2 subwoofer) for the G35 coupe so it'll sit tucked away. I have very limited trunk space and would like to preserve it if at all possible. The woofer in that Stealthbox is rated from 75-300w, I believe, so would it work well with that amp?

Lastly, I really don't want to run more than one amp since my car's space is very limited. That said, I am planning to power the Kappa 62.9i 6.5" rear side speakers using the factory wiring directly from the Eclipse HU. I've read that those speakers are really just for "filler" noise, especially considering I hardly ever have anyone in the back seat.

My goals with this system are to provide a completely upgraded sound system that will create a dynamic audio experience inside the cabin. I am not into excessive bass, and just want a little punch to match up with the other upgraded speakers that will be putting out more power. Does this sound like a good approach? I welcome your comments/advice.

Instead of the Alpine PDX-5, what do you guys think of maybe using the Polk PA1100.5 instead?

https://www.polkaudio.com/caraudio/pa/index.php?s=overview#pa1100_5

Stay away from the polk amp, stick with the alpine, The rest of your setup sounds decent im not a big fan of infinity products though.Nothing bad about them I just feel like there are so many better products out there in that price range. mb quart, alpine, jl audio etc.

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-A vision without a plan is just a hallucination-

spmpdr wrote:

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Stay away from the polk amp, stick with the alpine, The rest of your setup sounds decent im not a big fan of infinity products though.Nothing bad about them I just feel like there are so many better products out there in that price range. mb quart, alpine, jl audio etc.

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I've heard that some are saying the Alpine lacks punch. But at the same time I'm not really trying to blow my doors off! My goals are pretty modest, actually. And I know Alpine makes high quality products. Do you have any personal experience with Polk amps?

No I don't have personal experience with Polk amps,but I have owned several alpine amps and never been disappointed. I do have experience with there speakers and was not very impressed.I just believe when it comes to amps reliability and longevity are more important than overall power because if the amp doesn't work then there is no power. Also I would be willing to bet alpine outperforms polk hands down.

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-A vision without a plan is just a hallucination-

What do you think of the JL Audio HD Series amps? I could stack a set of those to get my 5 channels...

https://www.audiojunkies.com/blog/966/jl-audios-new-hd-amplifiers

Now your talking jl audio is a great ,reliable brand. what amps are you thinking of going with? perhaps a 4 channel and a monoblock?

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-A vision without a plan is just a hallucination-

spmpdr wrote:

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Now your talking jl audio is a great ,reliable brand. what amps are you thinking of going with? perhaps a 4 channel and a monoblock?

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Yeah, precisely. I think I might be able to stack those puppies right where my OEM Bose amp sits. They're tiny!

If it were my setup I would run the front components off two channels of the four channel amp and the 6x9s off the other two channels run. run the rear door speakers off the deck and leave them stock, (if your not going to amp them then no need to spend extra money on after market speaker). Then use the monoblock for the sub of course. the rear door speakers and maybe even the 6x9s might throw your sound off,but i think if you amp the 6x9s it should sound fine.

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-A vision without a plan is just a hallucination-

Yeah I think I'm definitely getting those JL Audio HD amps. For now I'll get the 600 for the four main channels and pair it up with the 750 monoblock for my woofer. I'll run one 10" woofer in a 4080 driver-side enclosure for now and if I don't feel I'm getting enough ummph, I'll add another 10" on the passenger side. I'm assuming I'd need another (monoblock) amp to power a second 10" woofer, right?

spmpdr wrote:

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If it were my setup I would run the front components off two channels of the four channel amp and the 6x9s off the other two channels run. run the rear door speakers off the deck and leave them stock, (if your not going to amp them then no need to spend extra money on after market speaker). Then use the monoblock for the sub of course. the rear door speakers and maybe even the 6x9s might throw your sound off,but i think if you amp the 6x9s it should sound fine.

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You might not need another monoblock depending on the rms watts of your subs if you have 2 300 watt rms subs and a 750 watt rms monoblock then you wouldnt need another amp. Just run the speakers in parallel off of the one channel. I run 2 12s off a monoblock right now and it sounds great. I dont know if putting the sub on one side of the vehicle is a good idea I would think it would throw your sound way off.Where does your enclosure mount in the vehicle?

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-A vision without a plan is just a hallucination-

Cool, this is actually the news I was wanting to hear! That JL Audio HD 750 monoblock is pretty powerful, and since the 10w1v2 woofers I'm looking at (also JL audio, ironically) have an RMS rating of 150 (300w max), then this amp should be able to power them both with no issues right? I could easily fit the HD 750 and HD 600 amps in the OEM Bose amp location, I imagine.

Here's a link to the enclosure and how it mounts into the vehicle. I'd get one for each side (driver/passenger):
https://www.4080enclosures.com/shop4080/store/comersus_viewItem.asp?idProduct=1&image=3

spmpdr wrote:

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You might not need another monoblock depending on the rms watts of your subs if you have 2 300 watt rms subs and a 750 watt rms monoblock then you wouldnt need another amp. Just run the speakers in parallel off of the one channel. I run 2 12s off a monoblock right now and it sounds great. I dont know if putting the sub on one side of the vehicle is a good idea I would think it would throw your sound way off.Where does your enclosure mount in the vehicle?

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So would I do better to hook up the dual 10's in parallel or series? Being a 1-channel (monoblock) amp, the JL HD 750 would need a parallel/series config to support multiple woofers. If both woofers run at 4 ohms, should I use your parallel configuration to power them? Wouldn't that decrease the impedance?

So the JL HD 750 runs 750w RMS@1.5ohm-4ohms. If I run the dual 10's in parallel then the impedance drops to 2ohms, which the amp can support just fine. In fact, it looks like I should be able to run both subs to their max power output levels (300w max per woofer) if wiring in parallel.

Going in serial does the opposite, right? So it'd raise the impedance level of the speakers, essentially taking them up to 8 ohms, which that amp doesn't support, correct?

Thanks again for all the guidance!

Okay guys, I have to switch gears for a second...

I was pretty set on getting a pair of JL Audio HD amps (750 and 600) to take care of my four main channels and the sub channel, however it turns out that I am able to get a great deal on the Polk PA1100.5...

That said, will it work for my requirements? As of now, I think I'm going to get two 4080 enclosures, and put JL 10w1v2-4 woofers in them. Would the Polk amp be able to power the four main channels (125x4@2ohms), in addition to two woofers on the sub channel? Seems like a lot for one amp to handle. Keep in mind those JL subs run 150w RMS each @ 4 ohms. I was thinking I could hook them up in parallel so they run at 2 ohms. The Polk amp runs 600x1@1ohm for the sub channel. Is this a good option to power my system? I will literally spend like $200 for my amplifier needs vs. about $1000 for those JL HD's. But I want to make sure it's gonna work!

As for physical fitting, based on some other G35 owners pics of the JL 500/5 mounted in the OEM Bose amp location I think the Polk amp would actually fit in there (though it'd be tight). It's six inches longer than the JL, but I think there's some room to extend a bit more if necessary, as noted from the pics I saw.

Thanks!
Brian

The polk amp will work but for how long?,That would be my only concern.I know the jl amps are spendy but they are very good and reliable. You should be able to find them for alot cheaper than 1000 bucks too. Also if you wanted to get a smaller monoblock for your subs you could,If each one of subs is 150 watt rms then thats 300 watts rms total. So you just need a 300 watt rms rated amp ,it can be a 2 channel class a/b or a monoblock , that alone could save you a few hundred bucks ,because the amps you have selected are to big,but would work,Try to match your rms ratings and ohm ratings amp to speaker.then you are almost perfectly powering what you have rather than under or over powering them .

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-A vision without a plan is just a hallucination-

Thanks,any idea if this amp would power two subwoofers wired in parallel?

Pioneer GM-D7400M

It runs 400w on a single channel at 2ohms. If I wire the woofers in parallel, then that should provide about 200w to each woofer, as the impedance will drop from 4ohms to 2ohms, is this correct? But that is still above the RMS rating for the subs.

Maybe I should abandon the concept of sharing a single channel amp for two subs, and just go with an amp that has two output channels rated at something like 150w x 2 @ 4ohms? Since these woofers are rated at 150w RMS, does that mean I should definitely NOT exceed that power level? Meaning should I just get an amp that gives exactly 150w to two channels at 4 ohms?

If so, here's a good candidate:
https://mobile.jlaudio.com/products_amps.php?amp_id=436

I guess, in general, it'd be good to know if I should target my amplifier's output to the RMS (not the max) rating of each speaker to be powered. Is this the way to go?

TIA!
B

yes you should try to match the rms rating of the speakers,to the rms rating of the amp,The rms rating is the continuous amount of wattage OF A SPEAKER OR AN AMP.So the closer they are together more efficient your set up is.What is the rms rating of that jl audio amp per channel and ohm load,if it is 150 watts rms @2ohms or 4ohms(stereo) you are good.I would recommend a monoblock still because alot of them are rated class d wich is a better than a/b when it comes to subs.Im sure you can find one that is 300 watts rms.But that 2channel jl is a very good choice too as long as it is to those specs above.I looked at the link and couldnt find the specs.

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-A vision without a plan is just a hallucination-

Thanks, that JL Audio amp above is rated as follows:

Rated Power (2 Channel Mode): 150 W RMS x 2 @ 1.5 ohm-4 ohm (11V-14.5V)

I can get a monoblock, but I guess I want to make sure that the single-channel amp will be able to adequately, reliably power two subs. Is it generally better to go with a 2-channel sub when you're powering two subs, or is it very common to just run them in parallel off a monoblock?

Thanks...

It is very common to run 2 subs off a monoblock but the amp you have is perfect for your application,It is up to you .The only problem I see with that amp is that its not stable at 2ohms bridged but you running in stereo anyway so that doesnt matter.

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-A vision without a plan is just a hallucination-

Sorry for the newb question, but what's bridged vs. stereo? Does bridging mean you're combining the two channels into one, more or less, whereas stereo is using both channels separately?

spmpdr wrote:

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It is very common to run 2 subs off a monoblock but the amp you have is perfect for your application,It is up to you .The only problem I see with that amp is that its not stable at 2ohms bridged but you running in stereo anyway so that doesnt matter.

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Yes bridged means two channels for one speaker (mono)This way doubles the power and lowers the ohm load but the signal isnt as clear.In your case one channel per sub (stereo)This is the cleanest way to get great sound .Dont worry about the questions ,thats how you learn.The dumbest question is the one never asked.

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-A vision without a plan is just a hallucination-

Thanks again! I am very grateful for all the advice!

Take care,
B

anytime man,post pics if you can and best of luck to you

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-A vision without a plan is just a hallucination-