I did not want to hijack the other thread so here is my situation:

I have the stock non-bose system comprised of one HU (built in 120w amp), a pair of component speakers in the front door, and co-axils in the rear door. I believe these are 4 ohm. I do NOT know if the output from the HU is factory equalized for the factory speakers.

I want to accomplish cleaner, tighter sound including being able to actually hear certain sounds that are muddy right now (e.g. progressive synthesizer sounds). I do not need a loud or vibrating system.

Given the above scenario:

1) Does upgrading just the speakers make sense when the output from the HU could be equalized for the factory speakers?
2) If so, should I go with 4 ohm?
3) If so, should I go with 2 ohm?

Thanks

 

Well stated, great post!

Based on my experience, I have to tell you that I would bet $100 cash that the HU is not equalized at all. Since the Bose HU output is not equalized, I find it terribly unlikely that Infiniti would spend ANY NRE on putting an EQ curve into the "lower-end" system. I appreciate that I don't know since I haven't tested it yet... but I'm VERY confident.

Based on your goals, would it be fair to say that you don't need the system to be any louder, but you do want it to be clearer and more detailed?

IF that is correct, then I will say that you should upgrade with 4 ohm speakers.

I find it highly unlikely that the non-Bose system has 2 ohm speakers. However, even if it does, a loss of 3dB of loudness (with a 50% reduction in output power) will not kill you given your stated goal.

HOWEVER, if you replace 4 ohm speakers with 2 ohm, your amp will definitely increase in distortion and sound worse, because it's not a good amp and is not designed for 2 ohm loads. It might even blow up eventually from operating at that lower impedance (unlikely, but conceivable).

I seriously doubt that your system will do 120 watts without a tailwind while going downhill and lightning striking your car. That's 30 watts x 4. If you assume that "rating" is assigned the way head unit poower is, it's about 15W RMS at 4 ohms. WHen you say it's "built-in", what do you mean exactly?

The reason this is important is that if the "amp" is built into the radio, it lacks any sort of DC-DC power supply. In that case, it's probably capable of about 15W RMS, and that is a significant limitation on the speakers you can use. If it's external, it might be OK, especially if its the size of a hardback book. If it's the size of a pack of 100's, then it's probably not too hot.

So component speaker kits with crossovers that sap power (anything with inductors inside) freak out those IC amp chips and often sound bad. That also limits the speakers you could choose. If the amp is inside the HU, for example, I would discourage getting the DLS UP6, even though I love those speakers, because they would not sound good and you'd be unhappy.

We make an upgrade kit for the Acura TSX which has a very wimpy OEM amp, and we have F tweets, F mids, and R woofs that work OK in that car. I haven't tried this in the G, mainly because of lack of opportunity, but we could probably make a kit with 6.5 woofers and 25mm silk tweeters in front and 6.5 drivers in the rear just for bass.

 

100% correct.

I got the 120W rating from the original brochure. Since the "amp" is built into the radio then you have a valid point that we're only talking 15W in reality.

OK, makes sense, I'm with you so far.

Yeah but you're point above about more power being needed for separates makes too much sense to me. It sounds like now I've got to invest in an amp and either LOC or another HU. Is this right?

One more note: I'm going to install V-MAX (cascade audio) sound dampening in my doors (inner metal panels) next week myself and add their DEFLEX behind the front mid-bass speakers. I'm doing this to see how much the sound will "tighten up" before going any further. Any thoughts based on your experience?

 

I LOVE Cascade and VMAX. ALL we use. I do not have valid results in testing Deflex panels - I've tried them, but never in a good test environment - and I am dying to hear your observations.

The components that we use in the CL-s and TSX kits use no inductors. We use a robust 25mm silk dome tweeter with a low mechanical resonance and then we put a very good-quality polypropylene crossover cap in series with it. We let the mid roll off on its own, having empirically verified that this works pretty well with the xover point we use with our tweeter, and we use a 5.25 in the front door for lower cone mass and better midrange off-axis. In those cars we use 6x9 woofs but in the G we would need to use 6.5 woofs. This is theoretical in nature until we get a chance to try it out.

It is certainly true that your best results are attained with a 4-channel amp and new speakers. For $700 or so you could get a great-sounding amp and speaker set. At our store we'd probably use DLS UP6, DLS CA41 4-channel amp,and avincar 6.5 woofers.

 

If the stock system has components up front already, wouldn't it be utilizing a crossover already? I don't follow why a comp set with a normal crossover using inductors might not work very well.....

 

They also only use a first-order capacitor for a 6dB/octave high-pass on the tweeter, and nothing on the woofer. Cone woofers usually roll off at some point at around a first-order rolloff (6dB/octave).

Their cap is crappy compared to mine... and their lightweight paper speaker has worse breakup modes at the top end compared to better speakers, but that's how they do it and how I do it.

When the inductor is added to the tweeter xover to steepen the slope to 12dB, it is across the wires (+ and -) between the cap and the tweeter. I don't know why for sure, but when I've tried this on low power OEM amps, sometimes they sound scary bad.

 

I think I understand, thanks.

IF you can come up with a kit for the G that is like the one you describe for the TSX and CL-Slike, could you PM me a cost? Thanks