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If you use the signal coming from the output side of the factory amp to the rear door speakers, there is no crossover to deal with, it is a full range signal. The factory speakers had a cap/coil crossover built onto the side of the magnet to protect them. I was using this signal for my LOC inputs and it rocked, but the OP's problem of the super high frequency was killing my tweeters as well. I am getting the parts together to build a resistor board to hook across the outputs of the Sony amp to see if it will stop that.
yeah i understand that. i'd still prefer to use the preamp signal wires and control it myself. i hate how if you turn the volume up high enough, the amp attenuates itself. pisses me off.
 

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yeah i understand that. i'd still prefer to use the preamp signal wires and control it myself. i hate how if you turn the volume up high enough, the amp attenuates itself. pisses me off.
I hear you. From what I have done in my car, I think only the bass gets attenuated as the volume goes over 3/4 or so. With my system installed now, I hardly ever even see 1/2 volume on the dial, and the LC2i uses Accu-Bass to compensate for the bass roll-off if I do go up that high. It is loud and clean now, just need to build the network to protect the factory amp from eating itself.
 

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BS man, you can tie in after the amp. have you see my videos? and it works just fine.
Yea, what he said.

Floor plan Plan Line Diagram Parallel

My "post amp" setup on my 2013 has been working fine as well and sounds wonderful. Looks like DDT's breadboard project may be a hot item for the 2014+ Sony folks.

-Scott
 

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I will be making a trip to Fry's after work today to gather the parts and build the network. I will put up a diagram and pic once it is done. This should protect the Sony amp and also keep that insane signal from getting to the tweets. I am using an active crossover, so testing will not be the same as most installs using the passive setup provided with most speaker sets, but in theory it should work for all '14+ models. I have a '14, build date 9/13. I will also see which version Sony amp I have and post that up too.
 

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Sweet. I should check that the focals that I want are active!

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Discussion Starter · #46 ·
Ok here is an update. I got everything replaced that was bad, blown, melted beyond repair. I have sent my oem amp to an engineer at Arc for him to look at. Ive installed my resistors and so far so good. Everything sounds good, still getting my full range signal from the rear channels. While i was tuning and after playing for about an hour at full throttle, oem amp is cool, my aftermarket amps are cool and resistors are cool. I noticed the little pop I use to get once at start up and turn off is gone. Everything is going good so far. Ive pitched an idea to Arc as well for a t harness type DSP that would have load resistors, DSP and line driver built in but not sure if it makes business sense to produce something like that.

Id like to make a few bold points since there still seems to be confusion on what I am talking about.

This effects 2014 and up MFT Sony systems only. So far seen revision AF and after on the amp.

This is across all 2014 and up MFT Sony systems, not just the FST but all ford products.

The rear outputs are full range signal and not EQ'ed out the a$$ like the fronts are even summing.

Here are some pics of my resistor block i put in and with all the cover plates back on finally. All connections to the amp harness are soldered and heat shrunk.

Electronics Technology Electronic device Electronics Electronic component Technology Electrical connector Electronic device Trunk Vehicle audio Subwoofer Vehicle Car Automotive lighting Blue Light Electric blue Vehicle audio
 

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I finished installing the JBL GTO-5EZ amp I mentioned earlier in this thread. I made my own harness for the speaker outs to feed the amp and then I spliced into the factory wires for the doors. I am feeding the sub part of the JBL amp the front and rear signal from the Sony amp since it gave me that option so I didn't even need to wire the sub input. I don't seem to be experiencing bass roll off but at the same time I am using the sub volume control. I can tell you the built in load is working fine and the Sony amp seems to like the setup. The system sounds much better. I used the set up CD that came with the amp to set my gains to their optimum level. I still have to tweak the crossovers but all in all I am very happy with the amp and the fact I didn't have to spend a lot of money on other equipment. Mind you this set up is for clarity and more volume, which I achieved and not to blow anyone away. It almost feels like JBL designed this amp for our systems. At $230.00 dollars out the door it's a great investment for an upgrade. If you want to see some pictures I posted them in the full system upgrade section of the forum. Thanks again guys for all the info in this thread.
 

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That's really clean. Much better now that you can run factory amp back under the trunk. This gives me more hope for this winter :)

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All I want is st3 package with st1 stereo :( not looking forward to doing a processor in this car.
That is basically what I have. I have what would be an ST3 in the US except it came with the ST1 stereo. Every ST in Canada comes equipped as an ST3 except you have choose of stereo.
 

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Here is the resistor box I made fir mine. Added a cooling fan and put a box around it just in case.


Drive it like you stole it!
 

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Here is the resistor box I made fir mine. Added a cooling fan and put a box around it just in case.


Drive it like you stole it!
Mounted on a breadboard?

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Discussion Starter · #52 ·

Here is the resistor box I made fir mine. Added a cooling fan and put a box around it just in case.


Drive it like you stole it!

Very nice, I didn't spring for a fan yet. I figured id see how it worked out first and so far the resistors are staying pretty cool, well I mean cool for a load resistor.

So far so good still playing good no issues.
 

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Yes, the board came with the box.


Drive it like you stole it!
 

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Hey faSTenough

Your post really got my attention, I just recently installed my amp to run my front components and would like to address this asap.

I have had a good read through but I'm not sure what I need to do to fix this issue. Could you give me a hand with what I need to buy and where I need to put them in the system.

I have the front left right speaker signals going to the LC2i, from there it is straight to the amp. Front tweeter signals are not going anywhere but everything else is still connected to a speaker.

Thanks in advance



Ok guys as you know Ive built a pretty extensive system for my 2014 ST with the MFT Sony system. I have had nothing but problems out of this system since day one.

This ONLY applies to 2014 and up MFT Sony systems. There doesn't seem to be any issues with the 2013's and it seems to be across the entire Ford line as I am hearing issues with F-150s ect with the MFT Sony sytem.

The issue is the OEM Sony amplifier which is a class D digital amplifier is having its output filters damaged by not seeing a load thus sending super high frequencies through the output in the realm of 50K hz +. Now what that does is in turn sends these signals through your processor and into your amps. I have blown 2 capacitors on the output filters on my aftermarket amps due to the high frequencies as well as about 4 front right tweeters. Which can get irritating when your highs amp is $800 bucks and those tweeters are $100 bucks each.

This creates an issue because 1) there is no aftermarket solution for adding an indash receiver due to the fact that if you remove the MFT screen your car is inoperable. The CAN network fishes its way through that screen so you cant take it out, as far as relocating it causes other issues with the CAN network by extending those wires it increases the resistance and CAN networks rely heavily on resistance for its termination. Not to mention that there are about 50 wires that plug into that screen that you would also have to extend. 2) Signal can not be taken from any location prior to the OEM amplifier since it is a fixed level signal meaning no matter what you turn the volume to your speakers would play the same volume.

So as far as a solution, I am attempting to try to create a "dummy load" to put on the OEM amps outputs. In order to do this I had to purchase a new OEM amp since my outputs were already damaged and basically start over. I have 9 30ohm 5 watt through hole load resistors that I am making a resistor box to place across all the OEM amps outputs so the amp sees some load, and doesn't destroy itself.

I have also found that the only way I am able to get a full range signal is from the rear channels of the OEM amp. The front tweeter and mid outputs have some funky crossover points in order to make up for the factory Sony speakers short comings. I have summed the front channels together using an Arc Audio SRI and it lacks the brightness and depth and lower mid bass that I know my speakers could produce. Once I had the signal coming from the rear outputs the audio quality increased 100% now what that also means is that now I have no voice for my turn by turn directions on the nav and unable to hear audio when using Bluetooth phone. Bluetooth audio playback is fine but not for a phone call. I can live with that for my audio quality to reach its potential.

I am also working with an aftermarket company who let me know about the other issues that are coming up from this new MFT Sony revision in order to come up with a solution.

If you are only putting in a subwoofer chances are you will not experience any issues because you are most likely crossing over anything from 80 hz up so you wouldn't experience and issues but putting load resistors on it would still help to not damage your amplifier.

Using load resistor is good practice when coming off of any factory amplifier in which some of its channels will not be used for protection.

If you do this make sure to keep the resistors isolated from things that would be sensitive to heat since they will get hot.

I don't have all the answers at this point and will keep y'all updated on my findings after I experiment with the load resistors and finding from the people I'm working with on the issue
 

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@Horn Dog how good are you at reading a schematic wiring diagram? I can post one up showing how to hook up the load resistors, and I got mine at Fry's...10 ohm 10 watt wirewound resistors or anything similar will work. You need one resistor for each speaker that you have disconnected, so we are using 9 since we replaced all and got rid of the center channel.


Drive it like you stole it!
 

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Hey DDT1972

I should be able to read it, unless it is really complex. The only channels that are disconnected on my system is the front tweeter and front midbass. The front midbass is currently connected to the LC2i. Do those two channels still need a resistor?

Thanks
@Horn Dog how good are you at reading a schematic wiring diagram? I can post one up showing how to hook up the load resistors, and I got mine at Fry's...10 ohm 10 watt wirewound resistors or anything similar will work. You need one resistor for each speaker that you have disconnected, so we are using 9 since we replaced all and got rid of the center channel.


Drive it like you stole it!
 

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Here is how I wired in my load resistors, replaced all the speakers and deleted the center channel...

Before I put the resistor in my factory amp was getting really hot even though it was not connected to anything other than the LC2i, now with the load resistors it barely gets warm at all. I chose wire-wound resistors from Fry's 10 ohm 10 watts, but anything similar should work fine as long as it is above maybe 8 ohms and 10 watts.



Drive it like you stole it!
 

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Discussion Starter · #58 ·
Also get your signal from the rear speakers so they aren't crossed over and eq'ed to hell and back.
 

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So let me ask this. I have a 2013.

Would it be incorrect to say that I could simply take my line-out for the rear speakers, Y them (so I have 4 outputs now) and plug that into the 4 "hi input" channels of a regular run of the mill amp, then send that to the passive crossovers of the speakers in my front and rear doors? I'd then disconnect the 'front outputs' from the OEM amp altogether.

So 2 questions in the assumption above:

1) I'm assuming that with the 2013 amp, I won't hurt anything by removing the front-outputs altogether from the OEM amp (I've had the center speaker disconnected for some time now) ?
2) Can Hi-Inputs from an amp accept amplified signals (i.e.: form the OEM amp)? I know they're designed for outputs from head-units where the power is typically much lower. Just want to ensure it'll work from an amplified source too. I imagine it would - the volume knob would just be 'touchier' since output levels (volts basically) are going to ramp up much quicker than a lower wattage hi-level source from a head-unit?

If I'm reading this thread correctly, 2014 issues aside, if I utilize the rear channel OEM amp outputs, I could just wire this all up like I would any other vehicle via hi-level inputs of an aftermarket amp.

Let me know if I'm missing something!
 

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Theory sounds good, just be sure to check the voltage (A/C volts) coming out of the factory amp and make sure it isn't above like 7-8 volts, most amps don't like it above that.
 
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