# FOCAL KRX3 AMP / SETTINGS



## andreszo (Aug 20, 2013)

Hello!
I have been reading this great forum for months and now I need a piece of advice.
Turns out I will be installing a set of Focal K2 Power KRX3 which I purchased about a year ago brand new. However, I still have many doubts so thats why I never dared to install them.
This is my current set: focal 165kr and JL hd900/5, audison bit one, oem HU (RCD-510) and focal 27kx subwoofer. New Alpine HU is on its way (INA w910) and will be installed as soon as its gets here. I am trying to decide between a fully active 3 way front stage and passive way. First, keep in mind this is not the bi- ampable set, this is the regular one. It is been said this is a very demanding set of speakers, which drops until 1 ohms if it is used with passive crossovers. Installer recommends a fully active set, but I would need one more amp, focal fps-4160 and jl audio hd600/4 are some options for this, which one would you choose? (I can get any of them almost at the same price). Anyone running krx3 fully active? If so, what amplifiers do you have?

Thank you in advance for your help.


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## CrossFired (Jan 24, 2008)

I'd go for the old school Class AB, focal fps-4160 for the SQ.


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## Mitsu1grn (Sep 22, 2008)

Greetings!

The KRX3 with the passive network used will produce a .8 ohms stereo load and most of the class D full range amplifiers will not play them. The FPS 4160 will as will most quality class AB amplifiers. 

That being said, if you wish to go fully active, you will need adjustable crossovers that will allow you to build a band pass network for the 3.5 inch midrange. 

The tweeter and midrange do not need more than 75 watts each going to them. The bass driver will be very happy with about 150-200 watts. 

If you use the enclosure that is included in your kit for the mid and twt I can recommend crossover points and slopes for you that should give you a good place to start if you are going to tackle this yourself.

I do recommend you have an authorized Focal dealer install these for you. They are an exceptional speaker system if it is tuned correctly and installed correctly. Please note that all Focal car audio speakers are designed to be listed to off axis, not on axis. 

If you have any questions please ask, I'll do my best to answer them!

Nick Wingate
Focal America


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## andreszo (Aug 20, 2013)

CrossFired said:


> I'd go for the old school Class AB, focal fps-4160 for the SQ.


Thank you, I definitely love small footprint of HD, and of course the fact that I can stack hd600/4 and the hd900/5 . On the other hand, gold plated terminals of fps4160 persuade me and that it is stable at 1 ohm, so in the case I can not set the speakers fully active I can still go passive safely. I have to make up my mind next week due to this proyect has to start asap!

Some specs for the record :
FPS 4160​4-Channel Class AB FPS Series Amplifier
RMS Power Rating @ 14.4V:
4 ohms: 120 watts x 4 chan.
2 ohms: 200 watts x 4 chan.
Bridged, 4 ohms: 380 watts x 2 chan.
Unique circuit designed dual power supply ensures stable performance under any conditions
LED power (green) and protect (red) indicators
Bass remote level control included
Dynamic soft clipping protects speakers from distortion
Direct mode available for quality active amplification
4-Channel/2-channel operation
Speaker-level (high-level) inputs
Preamp RCA outputs to daisy chain multiple amps
5-Way System Protection circuitry (Short circuit, Thermal overload, Soft clipping, High voltage, Polarity reversal)
Optional High Cap (FPS-CAP) outboard capacitor module increases power efficiency
Thermostat controlled, progressive-speed cooling fan keeps amp operating at safe temperature
Heavy duty aluminum alloy heatsink for extreme heat dissipation
Gold-plated RCA level inputs
Gold-plated screw terminals
Adjustable Low-Pass Filter (50-5000 Hz)
Adjustable High-Pass Filter (50-5000 Hz)
Adjustable Bandpass Crossover (50-5000 Hz)
Input Sensitivity: 0.2V - 5.2V
Frequency Response: 10-52,000 Hz
THD (Total Harmonic Distortion): 1%
Input Impedance: 13k ohm
Signal-to-Noise Ratio: 92 dB
Fuse Rating: 40 Amp x 2
CEA-2006 compliant amplifier
Dimensions: 10-3/4"D x 16-7/8"W x 2-3/8"H

*​*JL Audio HD Series 4-Channel Class D Amplifier
RMS Power Rating (11V-14.5V):
4 ohms: 150 watts x 4 chan.
3 ohms: 150 watts x 4 chan.
2 ohms: 150 watts x 4 chan.
1.5 ohms: 150 watts x 4 chan.
Bridged RMS Power Rating (11V-14.5V):
Bridged, 8 ohms: 300 watts x 2 chan.
Bridged, 6 ohms: 300 watts x 2 chan.
Bridged, 4 ohms: 300 watts x 2 chan.
Bridged, 3 ohms: 300 watts x 2 chan.
MOSFET power supply
Remote bass level input (HD-RLC required and sold separately)
LED power indicators
4/2 channel operation
Speaker-level inputs
Preamp RCA outputs
Single Cycle Control?
Heavy duty aluminum alloy heatsink for heat dissipation
RCA level inputs
Screw terminals
Variable high-pass filter (50-500 Hz, 24 dB/octave)
Variable low-pass filter (50-500 Hz, 24 dB/octave)
Frequency response: 20-20,000 Hz
Optional wired remote level control: JL Audio HD-RLC
Optional stacking equipment for HD amplifiers: JL Audio HD Stack Kit
Dimensions: 10-13/16"L x 8-7/8"W x 1-15/16"H


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## andreszo (Aug 20, 2013)

Mitsu1grn said:


> Greetings!
> 
> The KRX3 with the passive network used will produce a .8 ohms stereo load and most of the class D full range amplifiers will not play them. The FPS 4160 will as will most quality class AB amplifiers.
> 
> ...


Hello Nick!

Audison Bit One is part of my gear, so band pass for mids is covered. Not sure if I am using the enclosures provided yet, but I can manage to get the same volume of them for custom enclosures. And, crossover and slopes will definitely help. About a focal authorized dealer, trying to get the best professional around here. 

I promess keep this thread updated! 

Thanks!


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## andreszo (Aug 20, 2013)

Hello guys!

Finally Santa got me the fps 4160! I was not sure if it could handle the krx3 in bridged mode, due to .8 omhs stereo load. Fortunately, Focal headquarters confirmed by phone to america authorized dealer that fps 4160 can safely run krx3 in bridged mode. Anyway, an indoors test will be made in passive mode to be totally sure. 
I have to wait for some days to install it on my car due to the lack of good rca connectors in my town. By the way, I currently have monster 402xln rca cables, but I see they are discontinued. Any advice on rca? what about gold plated rca cables?

Cheers!


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## andreszo (Aug 20, 2013)

Some pics!


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## jhnkvn (Mar 26, 2011)

I'm running a full-active Focal KRX3 on Audison VRx 4.300 and a Focal FPS 4160.

As for your RCA cables, just don't go overboard on their prices. Just pick out a trusted brand and go from there. Don't just look at car audio RCAs but give home audio RCAs a try so not to limit your selection.


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## andreszo (Aug 20, 2013)

Thanks jhnkvn. I was not sure about sticking with monster xln 402, which I think are very well builded rca, and the set of focal elite I fortunately took for testing from a local store. I love gold finish of focal but monster xln look very strong and durable. Well, before making up my mind, here is a versus photo shoot: :surprised:

Edited: Unfortunately, I can not insert images on the forum


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## The real Subzero (Apr 13, 2010)

I run fully active. Old Alpine amps and an old Pioneer active 3way network deck. Running active, I have not needed to gain up as much as I did with the passive crossovers hooked up. Watch the gains, dont burn up your speakers.


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## MariusKrx3 (May 16, 2014)

Hello guys !

I have KRX3 for front and KRX2 for rear...and i allso buy 2 x fps 4160 focal amplifiers + 3sixty.2 sound processor.

Wich is the best setup i can make with them ? Personaly i want to get the best possible result in sound with them.


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## The real Subzero (Apr 13, 2010)

MariusKrx3 said:


> Hello guys !
> 
> I have KRX3 for front and KRX2 for rear...and i allso buy 2 x fps 4160 focal amplifiers + 3sixty.2 sound processor.
> 
> Wich is the best setup i can make with them ? Personaly i want to get the best possible result in sound with them.


If you already have, put the krx3 up front and the krx2 in the rear.


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## mughal90 (Sep 8, 2011)

Hi guys, m running krx3 full active. Jus got them wired active yesterday. Using mcintosh amps and helix cdsp. Can u guys share the crossover and slope settings u are using ?

My drivers are on A pillars directed towards centre of the cabin. To start off my settings are 

25-70hz / 70 - 400hz / 400 - 4khz / 4khz - 20khz. All slopes 24db using linkwiz


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## The real Subzero (Apr 13, 2010)

mughal90 said:


> Hi guys, m running krx3 full active. Jus got them wired active yesterday. Using mcintosh amps and helix cdsp. Can u guys share the crossover and slope settings u are using ?
> 
> My drivers are on A pillars directed towards centre of the cabin. To start off my settings are
> 
> 25-70hz / 70 - 400hz / 400 - 4khz / 4khz - 20khz. All slopes 24db using linkwiz


My woofers are playing from 65hz to 175hz, my mids are playing from 175 to 3.5k, and tweeters from 3.5k and up. 
sub plays 65 - 20


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## Mitsu1grn (Sep 22, 2008)

Greetings!

Fully active I would recommend the following xover and slopes:

Tweeter: 3.2khz and up -18 db per octave

Mid: low pass 3.2khz at -12 db. High pass 500 hz at -12 db. 

Bass: low pass. 500 hz at -12 db. High pass 65 hz at -24 db. 

Should be a good place to start. 

Nick Wingate
Orca Design


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## hawaiiguy (Apr 11, 2015)

Mitsu1grn said:


> Greetings!
> 
> The KRX3 with the passive network used will produce a .8 ohms stereo load and most of the class D full range amplifiers will not play them. The FPS 4160 will as will most quality class AB amplifiers.
> 
> ...


Hi Nick and Board, Would the Focal FPS 2160 also safely run this set of speakers. I also have the KRX3 with non modified crossovers and have been considering a few options the past month. Or the FPS 2300 RX?

I really like the reviews on the FPS and would like to add that to run this set of speakers. Though I didn't read any info that said this or the 4160 were 1 ohm stable. I am thinking the difference between the two amps is just 2 more sets of monoblocks as I read thats how they were designed. 

Thanks for input, by the way what is the current model of A/B focal amps not that these are discontinued?


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## SouthSyde (Dec 25, 2006)

hawaiiguy said:


> Hi Nick and Board, Would the Focal FPS 2160 also safely run this set of speakers. I also have the KRX3 with non modified crossovers and have been considering a few options the past month. Or the FPS 2300 RX?
> 
> I really like the reviews on the FPS and would like to add that to run this set of speakers. Though I didn't read any info that said this or the 4160 were 1 ohm stable. I am thinking the difference between the two amps is just 2 more sets of monoblocks as I read thats how they were designed.
> 
> Thanks for input, by the way what is the current model of A/B focal amps not that these are discontinued?


Nick is having problems logging in, but please send him an email at..

[email protected]

He will be happy to answer any questions you have!

Thank you


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## aroonkl (May 21, 2017)

Would Mosconi AS 200.2 be ok to do passive KRX3 ?


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## RVA_LVER (Apr 28, 2016)

aroonkl said:


> Would Mosconi AS 200.2 be ok to do passive KRX3 ?




Clean out your inbox. I tried to PM about Zero 3. 


Sent from my iPhone using Tapatalk


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