Zapco / Focal / JL, impedance, power-ratings, and some other questions...

[SRT-10 10+ year member]

Ok, here is the set-up:

Dodge RAM SRT-10 Quad-Cab (BIG cab needs big volume - LOL...)

2 sets of Focal 165K2P's - one set in doors / A-pillars, the other set in the RAM-specific Q-Logic custom kick panels. The specs, (and my dealer) say the K2P's will take 100w "nominally", all day long. However, there is something I am a little un-clear on, so I am hoping that perhaps some the gurus amongst you can kind of "layman's terms" it for me.

These are 4-ohm component sets. Ideally, you would run each set off of one channel of a 4-channel amp. So, then I start to look at impedance and the correlating power rating increases of some of the different 2-channel amps, and I start to scratch my head...

First off, if you were me, would you run a solid 4-channel amp (like a 300/4) on these sets, and let them "play" at 4-ohms all day long, or would you look at running them off of an even higher-power 2-channel amp, taking advantage of the 2-ohm stability (and subsequent power level increases) all of the higher-end 2-channel amps offer...?

I am still a bit of a newb with some of this stuff - so bear with me here - but am I correct in assuming that if you were going to run four component sets off of a 2-channel amp, you would connect two component sets to channel 1 and two component sets to channel 2, thereby showing the amp a 2-ohm stereo load (on each channel)? Assuming that I am correct so far, then how is the 2-ohm rated power "distributed"...? I will use the Zapco DC350.2 here as an example - at 4ohms, it is rated at 2x100w. But at 2ohms, it is rated at 2x170w. Now, you have added an additional component set to each channel to get the 2ohm load, but is that power being distributed "evenly" - that is to say, is each component set getting approximately 85w?

Bueller? Bueller? Bueller?

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[Echo42987 10+ year member]

Either way I would do a four channel amp that does 100+x4 at 4ohms. Just run the speakers at a 4ohm load. And or do a 2-Channel amp and run it at 4ohms there.

-Nick-

 

[SRT-10 10+ year member]

Either way I would do a four channel amp that does 100+x4 at 4ohms

Yeah, that was my original thought, but of my choices (Zapco, Focal, JL), I don't think one of them makes a true 4X100w 4-channel amp...

 

[Prowler573 5,000+ posts]

Ok, here is the set-up:
Dodge RAM SRT-10 Quad-Cab (BIG cab needs big volume - LOL...)

2 sets of Focal 165K2P's - one set in doors / A-pillars, the other set in the RAM-specific Q-Logic custom kick panels. The specs, (and my dealer) say the K2P's will take 100w "nominally", all day long. However, there is something I am a little un-clear on, so I am hoping that perhaps some the gurus amongst you can kind of "layman's terms" it for me.

When looking at audio equipment take notice of the Nominal or RMS wattage ratings. Peak or Maximum wattage rating values are good for nothing more than marketing and as such can be dismissed out ofhand as an immaterial number.

These are 4-ohm component sets. Ideally, you would run each set off of one channel of a 4-channel amp. So, then I start to look at impedance and the correlating power rating increases of some of the different 2-channel amps, and I start to scratch my head...
First off, if you were me, would you run a solid 4-channel amp (like a 300/4) on these sets, and let them "play" at 4-ohms all day long, or would you look at running them off of an even higher-power 2-channel amp, taking advantage of the 2-ohm stability (and subsequent power level increases) all of the higher-end 2-channel amps offer...?

Since your plan is for both sets of components to be up front with you (and people think having components both front and rear pose imaging problems!!!) fading ability isn't something you're going to miss were it gone. With that being said it will realistically boil down to what you can source that best fits your needs and/or intended budget.

I am still a bit of a newb with some of this stuff - so bear with me here - but am I correct in assuming that if you were going to run four component sets off of a 2-channel amp, you would connect two component sets to channel 1 and two component sets to channel 2, thereby showing the amp a 2-ohm stereo load (on each channel)?

Correct.

Assuming that I am correct so far, then how is the 2-ohm rated power "distributed"...?

Energy follows the path of least resistance so assuming the resistance shown to the amp output matches from one component set's crossover to the other that power would be distributed evenly across both sets. Conversely if you were to connect an 8 Ohm driver and a 4 Ohm driver to the same output the 4 Ohm driver would receive more of that channel's wattage output due to showing the output a lower resistance value and consequently being easier for the power to be able to flow into it.

I will use the Zapco DC350.2 here as an example - at 4ohms, it is rated at 2x100w. But at 2ohms, it is rated at 2x170w. Now, you have added an additional component set to each channel to get the 2ohm load, but is that power being distributed "evenly" - that is to say, is each component set getting approximately 85w?

See above.

 

[SRT-10 10+ year member]

Dude, GREAT reply - thanks - brings about a couple of more inquiries...

Your comment about imaging - my understanding is that component sets front and rear (as you mentioned) provide awful imaging and a totally off sound-stage, but to run two component sets up front, I would still achieve a relatively balanced and good image / sound-stage, and have the benefit of increased volume / SPL, inherently due to the fact that I am simply "doubling" my speaker / power capacity up front...

Fade schmade - it's my truck, and I never sit in the back anyway... LOL...

Ideally then, is there ANY sound quality differences between a 4-ohm load (4-channel amp driving four component sets) and a 2-ohm load (2-channel amp driving four component sets)

And ideally then, Zapco or Focal?

 

[Prowler573 5,000+ posts]

Dude, GREAT reply - thanks -

You're welcome. Some of us are actually here to help! //content.invisioncic.com/y282845/emoticons/thumbsup.gif.3287b36ca96645a13a43aff531f37f02.gif

Ideally then, is there ANY sound quality differences between a 4-ohm load (4-channel amp driving four component sets) and a 2-ohm load (2-channel amp driving four component sets)

Not that I have noticed personally. Not to the average set of human ears at any rate. The only real noticeable difference between one and the other will be the amount of current being drawn from your electrical system. Assuming that the system in question is up to the task of providing enough current to the gear you're running it should be a half-dozen of one or 6 of the other. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

And ideally then, Zapco or Focal?

That's really going to boil down to personal preference as you can't really go wrong with either. Both companies sell top-notch gear and I cannot see any end user being disappointed with either choice.

Sure you'll get the fanbois who are die-hard loyalists of one or the other but in the end they're really comparable gear with both brands being near the top of the spectrum as far as build quality, reliability, and overall sound quality are concerned.

 

[SRT-10 10+ year member]

Again man, thanks.

With regards to my imaging, am I going to run into difficulties with sound being "all over the place" with my intended speaker placement set up?

So, in theory, using JL as an example, as the slash series power ratings DO NOT change with impedance changes, a 300/4 at 4ohms will do the EXACT same job as a 300/2 at 2ohms - provide 75w to EACH of the four component sets (ideally, given each of the four crossover blocks is showing the amp equal resistance), correct?

Is JL a big "step down" from Zapco or Focal (going to be using a 250/1 to drive my 10w3v3 Stealthbox anyway...)

 

[Prowler573 5,000+ posts]

Again man, thanks.
With regards to my imaging, am I going to run into difficulties with sound being "all over the place" with my intended speaker placement set up?

As I am no expert in this particular department I honestly wouldn't be able to tell you without listening to it after it was installed. Hopefully someone with a bit more knowledge than I possess will chime in here soon.

So, in theory, using JL as an example, as the slash series power ratings DO NOT change with impedance changes, a 300/4 at 4ohms will do the EXACT same job as a 300/2 at 2ohms - provide 75w to EACH of the four component sets (ideally, given each of the four crossover blocks is showing the amp equal resistance), correct?

Yep. Both amps will feed 150 watts to the right side and 150w to the left side at any resistance between 1.5 and 4 Ohms. The only real difference there would be is an additional set of inputs/outputs on the /4 as compared to the /2 for your intended usage.

Is JL a big "step down" from Zapco or Focal (going to be using a 250/1 to drive my 10w3v3 Stealthbox anyway...)

I cannot see you losing anything really appreciable going either route...

 

[SRT-10 10+ year member]

Yep. Both amps will feed 150 watts to the right side and 150w to the left side at any resistance between 1.5 and 4 Ohms. The only real difference there would be is an additional set of inputs/outputs on the /4 as compared to the /2 for your intended usage.

Ok, given the fact that my budget is not really a concern, but I am really sold on JL from a quality, reputation, and price-point stand, if you were me, 300/2 or the 300/4 (an additional $168.00 in price difference) - which way would you go, and why?

 

[chucku 10+ year member]

A 300/4 is $168 more? Online its like half that. The 300/4 is more versitile but I have mine bridged to my mbq comps. Bridging a jl doesnt really do anything power wise. Run the jl 75x4 to your 2 sets of comps and call it a day. Later, if you want to go active add another 300/4 and send a channel to each driver!

 

[SRT-10 10+ year member]

A 300/4 is $168 more? Online its like half that. The 300/4 is more versitile but I have mine bridged to my mbq comps. Bridging a jl doesnt really do anything power wise. Run the jl 75x4 to your 2 sets of comps and call it a day. Later, if you want to go active add another 300/4 and send a channel to each driver!

Yeah, I am talking Canadian $$, list price(s) up here...

And I was toying with the idea (a little bit) of running two 300/4's (channel to each driver) - my dealer kind of laughed at me and said "dude, THAT would be pretty insane..."