R32 GT-R System Recommendations?

[lwells]

Just to add another question -- what is the difference between 2 Ohm and 4 Ohm gear, and specifically, in relation to subwoofers? Is either better/worse/indifferent?

LW.

[ferni]

Ohms is the loading the amp/speaker... and the way you wire it up..

Good amps (expensive) can be stable down to lower ohms - 1ohm stable .5 ohm stable etc..

means you can power more things off it (now i get mixed up here)

parrellel and series, one makes the ohms load go one way and the other the other way

ie 2 4 ohm speakers wired in parrellel will cause a 2ohm load to be put on the amp ( i think )

2 4 ohm speakers wired in series will cause a 8 ohm load to be put on the amp ( one way or the other )

not sure which is better/whey but i'm sure fhrx can tell us

As for that clarion unit, not sure - its bound to be good, i have the 835 cd/mp3/wma player (no screen since i find i have enough trouble keeping the car on the road without trying to watch tv) and i really thought it came down to wank factor, in a skyline anyway since its not a cruising/luxary car ...

[lwells]

ferni: thanks -- perhaps grand-master guru Fhrx can help us

Another question since I am piling them on, this time related to amps: is the LRx line of Audison good for my purposes, or should I be aiming higher? There seems to be huge jumps in amp prices from about 500-1000 to 1500-2000. Is the extra cost of something like the VRx line (or equivalent in other brands) worthwhile, or does it just buy marginal improvements and flashy cases?

Frhx: I noticed you don't list Rocjford Fosgate or Phoenix Gold amongst your preferred amp manufactures. I have been reading through thread in CAA and a number of people seem to suggest amps from these too manufacturers (although, in Rockford's case, the 2004 line more than the older stuff). Any particular reasons you don't suggest these brands?

Cheers,

Lucien.

[Fhrx]

We do recommend Phoenix Gold and Rockford but due to the fact that I have over 3500 products available to my fingertips I cannot list them all. :(

[Fhrx]

There are two main factors in the above post by ferni. Ohms and loading amps down.

Let's explain Ohms first.

Well lets see? Put simply, Ohms is the measurement of electrical resistance and system impedance. It is a measure of the degree to which electrons are limited in both velocity and quantity in passing through a circuit. In Impedance measurements, this takes into account, the mechanical resistance inherent in the motion of transducers. The standard is usually 4 ohms for car audio and 8 ohms for home and commercial audio. Some specialty woofers may be rated at 2, 6, 12 or even 16 ohms. You would have seen the 12 ohm JL's before no doubt.

Ohm's Law is the he mathematical relationship between voltage, current, and resistance. It is named after George Ohm, it's discoverer. Ohm's law states that current volume in a conductor is directly proportional to the voltage flow across it and inversely proportional to its resistance. In general, this means that more voltage will produce more current, if resistance stays the same, but higher resistance will cause current to decrease if voltage stays the same. In mathmatical terms, V = I x R, where V is voltage, I is current, and R is resistance. Ohm's law is a description of electron behavior upon which virtually all understanding of electronics is based.

Just for further background information, you might have heard all this called resistance of impedance so I'll give you a little more info on those two things as well.

Regarding resistance, almost all conductors of electrons exhibit a property called resistance. Resistance impedes the flow of current. It is measured in units called Ohms. With a water hose, resistance could be regarded as friction between the water and the hose. A larger hose would create less friction and have a lower resistance than a smaller hose. It could also be a finger over the hose end. In electrical circuits, small round cylinders with wires on either end are called resistors. These typically reduce the flow of electrons to serve the specific requirements of the circuit elements, such as amplification or switching functions.

Finally, Impedance. The totality measured in Ohms of all electrical opposition to current flow: resistance, reactance, capacitance, as well as all mechanical factors inhibiting the completion of energy transfer in a contained system. In practical terms, this means that most Drivers are assigned a certain nominal impedance based on their DC voice coil resistance and mechanical stiffness. For car audio this is usually 4 ohms; for home stereo, 8 ohms is the standard. Put simply, your voice coil has a certain amount of copper winds in the voice coil(s). If you want a high resistance, triple the amount of winds and the current suddenly has to do X amount more work to travel past the coil.

If all that seems like bollocks, think of a tap. Voltage is the pressure, the flow is the amperes and the ohms is your finger over the end. When you take your finger off, the resistance is lessened (eg 0.5 - 1 ohm) and the water pours out everywhere. When you begin covering the hose end the resistance goes up (4-8 ohms)...

Now amp loading.

Just a quick note on overdriving amps when loading them down. Remember that power specs are not the only thing you look at when purchasing an amplifier. There are other things such as damping factors, slew rates, s/n ratios, separation and THD figures to go on too. Then there is wieghting of the figures to consider too.

Just because an amplifier is X ohms stable doesn't mean you can simply load the amplifier down without risking something going pear shaped. Most Skyline motors are 8000rpm stable but you don't stay on 8000rpm all day do you?

My suggestion is always plan a system at 4ohms. If you need more bass, add another amplifier and subwoofer, don't just ring the neck of your existing amp.

Hope that cleared things up a little. As you can see neither way is 'better'. Series and parallel wiring configurations simply allow you move loading options.

[lwells]

We do recommend Phoenix Gold and Rockford but due to the fact that I have over 3500 products available to my fingertips I cannot list them all. :(

That's cool, was just wondering if you had explicitly not listed them It all seems a bit the same to me: so many similar products at the same price points with same features, its hard to know what is worth purchasing :headspin:

/me settles back to try and digest Fhrx's last post

LW.

[funkymonkey]

luce, as I said... too much money on ya hands lol.

I run 2 rockford amps in the car, one dedicated to my nakamichi 12" sub and one for my focal splits (which I've replaced for now with alpines till I work out how to make the custom pods etc). For the rears I bought dodgy JVC speakers and wired them straight into the head unit, as all I want them for is rear fill.

I was going for a very simple yet clear audio setup, not really doof doof.

BTW side note, FHRX do you offer the same 20% discount to us as you do to ozhonda forum members?

[lwells]

funkymonkey: don't worry, I am doing my best to "relieve" myself of my excess money issues

fhrx: ok, I think I got the just of that.. I was never much good at electronics, so I guess I can't expect too much to stick Anyway, thanks for the explanation. The reason I asked was that I have noticed that some subs come in 2 Ohm and 4 Ohm versions of the same model, so I was just wondering which was the wiser choice. So would I be right in saying that a 2 Ohm version would allow a less powerful amp to power it (as there is less resistence), but the 4 Ohm version will produce better/deeper bass if driven by an appropriate amp?

Finally, would an IDMax be overkill for the system I am building? They seem to be extremely well regarded on CAA for their response and depth of bass. One thing that just occurred to me: is there an optimal sub enclosure size for all 12" subs, or does it vary according to model? I have noticed that some subs seem to have a lot of, errr, "stuff" behind the actual driver, while others basically just have the driver with some wires running out the back. Is there some reason for this difference?

Maybe I should actually demo some of these things first

Cheers,

Lucien.

[Fhrx]

BTW side note, FHRX do you offer the same 20% discount to us as you do to ozhonda forum members?

We do but each month different forums I'm a member of get different discounts etc. But it never hurts to email me because I'll support the Skyline forums anywhere I can.

[Fhrx]

fhrx: ok, I think I got the just of that..  I was never much good at electronics, so I guess I can't expect too much to stick Anyway, thanks for the explanation. The reason I asked was that I have noticed that some subs come in 2 Ohm and 4 Ohm versions of the same model, so I was just wondering which was the wiser choice. So would I be right in saying that a 2 Ohm version would allow a less powerful amp to power it (as there is less resistence), but the 4 Ohm version will produce better/deeper bass if driven by an appropriate amp?

Know the feeling, I am still learning everyday about how things work too.

2ohms would need a stronger and more controlled amp to run it. More current flows at 2ohms than 4ohms so your amp needs to be able to control this larger current flow.

On the matter of sound quality, resistance cannot be equated to sound quality. It all depends on the amplifier driving the sub as some amps are built to run at 1ohm, some are built to run at 20ohms etc...

[Fhrx]

Finally, would an IDMax be overkill for the system I am building? They seem to be extremely well regarded on CAA for their response and depth of bass. One thing that just occurred to me: is there an optimal sub enclosure size for all 12" subs, or does it vary according to model? I have noticed that some subs seem to have a lot of, errr, "stuff" behind the actual driver, while others basically just have the driver with some wires running out the back. Is there some reason for this difference?

Every subwoofer needs a specific volume of air behind it to achieve the bass response that the installer desires. It's not just different between subs either. An IDMAX12 in your car would need a different enclosure if it was in a Hummer or Caddy because you would need a different response curve (larger for more boom)...

The stuff, you mean fibrefill? This is what we put into enclosure when the enclosure is too small (due to space restrictions)... the delayed airwaves fool the subwoofer into 'seeing' a larger enclosure behind it.

[lwells]

The stuff, you mean fibrefill? This is what we put into enclosure when the enclosure is too small (due to space restrictions)... the delayed airwaves fool the subwoofer into 'seeing' a larger enclosure behind it.

No, sorry, I didn't make myself very clear. I meant that looking side on, some woofers are a lot thinner than others. To use the JL Audio series as an examples, note how thin the 12W0 is compared to the 12W7:

Does that make more sense? The W7 seems to have a lot more room behind it for the magnet/coils/etc to move...

LW.

[lwells]

Know the feeling, I am still learning everyday about how things work too.

2ohms would need a stronger and more controlled amp to run it. More current flows at 2ohms than 4ohms so your amp needs to be able to control this larger current flow.

On the matter of sound quality, resistance cannot be equated to sound quality. It all depends on the amplifier driving the sub as some amps are built to run at 1ohm, some are built to run at 20ohms etc...

Oh dear, no simple answer than

LW.

[Fhrx]

No, sorry, I didn't make myself very clear. I meant that looking side on, some woofers are a lot thinner than others. To use the JL Audio series as an examples, note how thin the 12W0 is compared to the 12W7:

 

Does that make more sense? The W7 seems to have a lot more room behind it for the magnet/coils/etc to move...

LW.

It's like saying the RB26 looks different to the SR20. Two totally different speakers. The two afore mentioned subwoofers have different motor and suspension structures and are designed to output a different sound, receive different amounts of power and output radically different amounts of noise.

[lwells]

It's like saying the RB26 looks different to the SR20. Two totally different speakers. The two afore mentioned subwoofers have different motor and suspension structures and are designed to output a different sound, receive different amounts of power and output radically different amounts of noise.

Yes, I understand that much, I was just curious as to the actual purpose of the additional "stuff" (yeah, go the technical terms ) behind the woofer.

Does one particularly type dictate a larger sub box? The reason I ask is a don't want to surrender my entire boot to a subwoofer: I plan to do a custom sub box that moulds into one corner of the boot (with amps and various other bits on the other side) with a "stealth" type install, so loosing a vast quantity of my (already small) boot is not terribly desirable.

Shame there is no Stealthbox made for the R32 GT-R by JL

LW.

[ferni]

I think its larger/better quality magnets behind the speaker, not sure, but it seems common in speakers, the heavier/larger the magnets/stuff is behind the speaker, in regards to subs, or normal drivers (house or car etc..), the better quality...

Also this may help a little - http://ccs.exl.info/sp_wiring.html

[Penfold]

Just wondering Fhrx if its the Clarion VRX935VD thats the most popular CD/DVD/LCD head unit or what your recommendations are? I guess the competition is the Pioneer AVH-P or the Alpine CVA range.

Just that I'm looking for something in that ballpark & wondering what your current recommendation would be from a value for money point of view.

Cheers,

Penfold

P.S. Sorry for hijacking the thread Iwells but it sounds like you'd be interested too.

[lwells]

JP.S.  Sorry for hijacking the thread Iwells but it sounds like you'd be interested too.

Go for it -- I am in the market too, so happy to have it "hi-jacked"

The Alpine's are considered excellent but boy do you pay -- with the Clarion's you can import them from the US and just grab the AU tuner: apparently this doesn't work with the Alpines so you have to buy at local prices which are 2-3x greater.

Its a shame that AU prices are so screwed.. would much rather support a business like Frhx than some US company, but when there is that much of a differential (~$2500) then its hard not to let the pocket rule the heart.

LW.

[Fhrx]

Hmm... It is a large problem here...

[lwells]

Hmm... It is a large problem here...

Certainly is, and since the RRP is set by the manufacturers, its just price gouging: there is no way that shipping and distribution can account for the price difference

Stupid thing is that the Australian operations seem to be well aware of the problem and not care: Clarion Australia will happily modify a US-imported 935VD for multi-region (for a price, of course). Bizarre.

I feel for the local retailers: they just don't stand a chance

LW.