Installing under seat sub in Ford Focus Mk2.5

[doriangh]

Hello!

I am planning to install an Alpine PWE-S8 in my 2010 Ford Focus mk2.5. 

The sub came, but now I’ve gotten into a bit of trouble. Well, there’s kind of no place to put it without some modifications to the car.

I’ve stuck with my idea of putting it under the front passenger seat, as that seems like the best way without many changes. There seems to be just enough space to be able to stick the sub to the seat itself (rather than the floor) in a way as to not disturb the rear passengers, and to get a good fit.

What I’m planning to do is to improvise a base on the bottom of the chair as to hold the unit. I’m trying to mostly base the structure on the solid metal on the sides (the black bit) rather than the thinner silver metal that holds the “sponge”. That way I could place it upside down and not be in the way of the rear air con, and also leave decent room for the rear passengers. 

I’ve attached an image roughly where it should go. It goes deeper than what’s in the image, it’s just for good measure.

What are your thoughts on this? I have not started yet, as I am still planning on how to tackle this.

I would really appreciate if anyone has any better ideas on where to place the sub.

Thank you very much!

[StephenFord]

8 hours ago, doriangh said:

What are your thoughts on this?

With respect, I don't think you want to know my thoughts on this LOL 🤣

[doriangh]

53 minutes ago, StephenFord said:

With respect, I don't think you want to know my thoughts on this LOL 🤣

Something helpful would be really appreciated. I'm no expert, it's my first time trying this out.

[Lenny]

6 minutes ago, doriangh said:

Something helpful would be really appreciated. I'm no expert, it's my first time trying this out.

Not much room under the seat unless you lift the carpet to remove the air duct for the rear seat blower and even then; theres a 2" box iron section in the way; 

You could fit an MDF panel in the boot without any screws or damage to the vehicle atall, then mount the sub to it; alternatively scrap that sub and fit a 10" in the wheel arch using a model specific sub enclosure available on eBay. 

I've fitted two amps and sub with removable mdf panel on my mk2.5 

 

[doriangh]

7 minutes ago, Lenny said:

 

 

If I was going to do a boot install, that's how I would've liked it. Did you make the cover yourself? And where did you get the carpet to match the cars'?

Below the seat is just enough space to be able to do it. I'm going to someone that has the tools, and build an aluminium base on the chair to put the sub on. If there is space, could there be other things damaging?

 

[doriangh]

Also as a side question, if the sub is powered, do I still need an amp, or is the sub just enough? 

[Lenny]

2 hours ago, doriangh said:

Also as a side question, if the sub is powered, do I still need an amp, or is the sub just enough? 

I'm guessing this is your first sub or definitely your first time installing; which is perfectly fine; a sub needs an amplifier to move it in and out; the amplifier is an essential part of creating big sound,

Generally an underseat sub comes with an amplifier built inside; which may be what it means by being powered,

You will need to run either an 8AWG or a 4AWG positive power feed directly from the battery to the amplifer on the underseat sub and a shorter 12" maximum length 8AWG or 4AWG earth feed to a near by bolt on a ring terminal which fits like a washer on a bolt,

The RCA inputs to the amplifier then are two plugs which feed audio from the headunit to the amplifier; 

If you have a factory headlight then you will require a "high to low level RCA adapter" which will take a regular speaker cable in from your headunit and provide you with RCA socket outputs to plug your amplifier or underseat sub in to. 

[Lenny]

2 hours ago, doriangh said:

If I was going to do a boot install, that's how I would've liked it. Did you make the cover yourself? And where did you get the carpet to match the cars'?

Below the seat is just enough space to be able to do it. I'm going to someone that has the tools, and build an aluminium base on the chair to put the sub on. If there is space, could there be other things damaging?

 

Thanks,

I've done all myself and built the panel very easy I have a guide here, 

Bought the carpet in Halfords, need to paint the MDF to seal it and provide a smooth surface for some spray glue to stick to; then apply the carpet,

The panel has a cavity of 25mm where all connections are sandwiched between the panel and the back seat; it can be easy unplugged and removed if more boot space is required; I've also put in a socket from the headunit Speakers output so when the amp panel is removed you can then plug in to the headunit output to maintain audio but not as loud. 

Amp panel guide: 

Full list of my guides 

 

[doriangh]

Update. 

I've done it! 

Here's the result:

 

I've attached it completely from the chair. The bottom part was easy enough, just drilled 4 holes in the chair:

 

For the top part I've used two L metal brackets and, again, 4 holes in the chair:

 

Here's how it looks with the chair outside:

It retains full air vent functionality, and the foot situation is not that bad. The chair fully goes front and back. I've yet to attach the cables and update you guys on the process and final result + sound.

[doriangh]

I've managed to make the connections. I've tapped into one of the fuses from the fuse box (a 40A one) for the positive, and the negative hooked it on a screw on metal (for ground). So I've used only the red and black cables from the power adapter that came with the sub (I've taped the rest). I did this in order to keep the sub off when the car is off, and make it turn on when I turn on the power. Then I used a RCA cable to connect the sub (red/white) to the head unit (Kenwood DMX-7017 DABS).

It didn't work at all at first. I've tested all connections and they seem to work fine. The only thing that did it was turning on Loudness in audio features to high. A blue LED finally turned on on the sub. 

The problem is that it doesn't work all the time, just at random times, and it sound very bad. Like it's cranked up to the max all the time. There are gain and frequency controls, as well as a remote. For testing we turned the frequency and the gain to the max, so I'm wondering if that's why it sound bad, but it sounds the same even at low volume.

Can someone figure out what's wrong here?

Thank you very much.

[F0CUE]

You need to setup X’over then adjust the settings in SW Level. 

[doriangh]

Hi again. I've set up x'over and it didn't change anything. I'm beginning to think it might be a power + audio cable issue. I'll try getting power from the battery straight first to see if that fixes it. As I've said, I've tapped into one of the fuse's cable.

[F0CUE]

14 minutes ago, doriangh said:

Hi again. I've set up x'over and it didn't change anything. I'm beginning to think it might be a power + audio cable issue. I'll try getting power from the battery straight first to see if that fixes it. As I've said, I've tapped into one of the fuse's cable.

Seems like a lot of hassle for more bass. I hope you get it sorted. You directly tapped the fuse wires? If so not good best to use a piggyback. 

[StephenFord]

39 minutes ago, F0CUE said:

Seems like a lot of hassle for more bass.

Well, in the words of that famous 21st century philosopher, Meghan Trainor, 'It's all about the bass, the bass, the bass...' 😀

[doriangh]

39 minutes ago, F0CUE said:

Seems like a lot of hassle for more bass. I hope you get it sorted. You directly tapped the fuse wires? If so not good best to use a piggyback. 

Thanks for the reply. Well, I didn't think it would be this hard at first. I'm returning it if it doesn't work perfectly, since all this hassle cannot result in a mediocre result. I've piggybacked into a cable from a fuse.

[doriangh]

Just now, StephenFord said:

Well, in the words of that famous 21st century philosopher, Meghan Trainor, 'It's all about the bass, the bass, the bass...' 😀

I don't want it to be only bass. My intentions were to have a little more punch to the sound. Didn't expect such a proccess.

[StephenFord]

9 minutes ago, doriangh said:

I don't want it to be only bass. My intentions were to have a little more punch to the sound. Didn't expect such a proccess.

When you get to my age, you'll be happy with a radio that can get the news without crackle LOL

[TomsFocus]

1 hour ago, StephenFord said:

When you get to my age, you'll be happy with a radio that can get the news without crackle LOL

Give it a few more years and all you'll want is the whistly sport channel on AM frequency...  Remember many trips to Wickes or Ladbrokes with my Grandad listening to Radio 5 Live!  

[StephenFord]

7 minutes ago, TomsFocus said:

Give it a few more years and all you'll want is the whistly sport channel on AM frequency...  Remember many trips to Wickes or Ladbrokes with my Grandad listening to Radio 5 Live!  

Tom, I was brought up listing to Radio Luxembourg with my little transistor radio under the bedclothes broadcast on Long Wave (younger ones can google that!) Having said that, when I was 17, I installed a kickin' Pioneer head unit complete with matching graphic equaliser in my Datsun 120Y. That was way back in 1979, and I'm pretty sure 'car' sub woofers hadn't been invented yet LOL Oh, nice new avatar!

[TomsFocus]

I'm slightly worried about the effects on your passengers of attaching a sub directly to the seat frame.  Probably best to keep some wet wipes and a fresh pair of pants in the glovebox just in case!  

I do appreciate the desire for more bass though, not just to annoy the neighbours but it does a much clearer sound up front when the door Speakers aren't trying to deal with such a large range.  I had a 1000W JBL sub in the boot of several previous cars...until I became elderly and lazy!   Plus, standard systems have improved dramatically since the turn of the Millenium, I found the premium Sony audio in the Mk2.5 decent enough tbh.  I know the standard system with the paper Speakers in the pov models isn't so great.

[Lenny]

22 hours ago, doriangh said:

I've managed to make the connections. I've tapped into one of the fuses from the fuse box (a 40A one) for the positive, and the negative hooked it on a screw on metal (for ground). So I've used only the red and black cables from the power adapter that came with the sub (I've taped the rest). I did this in order to keep the sub off when the car is off, and make it turn on when I turn on the power. Then I used a RCA cable to connect the sub (red/white) to the head unit (Kenwood DMX-7017 DABS).

It didn't work at all at first. I've tested all connections and they seem to work fine. The only thing that did it was turning on Loudness in audio features to high. A blue LED finally turned on on the sub. 

The problem is that it doesn't work all the time, just at random times, and it sound very bad. Like it's cranked up to the max all the time. There are gain and frequency controls, as well as a remote. For testing we turned the frequency and the gain to the max, so I'm wondering if that's why it sound bad, but it sounds the same even at low volume.

Can someone figure out what's wrong here?

Thank you very much.

Can you show me a picture of the controls which you turned please mate;

Theres one that generally requires a screwdriver to turn; and some people assume that it should be turned up full but its actually for setting the Ohms 

I highly doubt that a single piece unit such as the one you have with the sub and amplifier built in together; I doubt that it gives the ability to adjust the Ohms as the speaker is already paired up with the amp as result should have been tuned by the manufacturer; but we will know if you can upload a picture please,

If you have adjusted the "input sensitivity" then you will need a multimeter and a syn wave CD to calibrate the amplifier for best results, not a big or expensive job but worth doing if possible on the device.

[doriangh]

I've finally done it!

I went out today and bought a car amp wire kit with really thick cables. Then I changed the power line from a thin wire from a fuse, to an accessory cable that was leading nowhere and had the exact voltage as the battery which was perfect. Also, yesterday I forgot to plug the power control cables (blue/white one) from the subs' amp to the head unit. I fixed that today.

This is the back of the unit:

Thanks to everyone for suggestions!

[Lenny]

26 minutes ago, doriangh said:

I've finally done it!

I went out today and bought a car amp wire kit with really thick cables. Then I changed the power line from a thin wire from a fuse, to an accessory cable that was leading nowhere and had the exact voltage as the battery which was perfect. Also, yesterday I forgot to plug the power control cables (blue/white one) from the subs' amp to the head unit. I fixed that today.

This is the back of the unit:

Thanks to everyone for suggestions!

Thanks,

I see it doesn't have an adjustment for input sensitivity so that's good in this case; the Ohms are already factory set,