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Abarth 595 Soundsystem

This post is a work in progress

Abarth 595 Soundsystem

A soundsystem upgrade on an Abarth 595, with 8 channels of class AB power, Twin 10″ subwoofers, Upgraded front end and audiocontrol sound processing, Oversized power wiring across the whole system, noise control applcation and the possibility of a future 3 way active and 2 way rear fill, 2-3000wrms on bass and fully DSP tuned.

Custom Android Headunit

Here’s the final layout for the interface it’s a real mixture of carefully selected apps, custom code and some photoshop skills that bring it all together. Overall I would say its nicer than most on the market!

The headunit is powered with a 3A supply connected via a 10A automotive relay.

Audio is currently routed via the 3.5mm headphone out untill I figure out DAC options

Fabricating the fascia

The tablet is held in place with a custom bracket fabricated from ABS plastic. It will then have a fiberglass moulded fascia built around it to cover the gaps and blend it into the dashboard.

I like the profile when it’s just resting up but I think it will need to be rotated forward a little to reduce some of the possible glare from the windscreen.

Upgrades to power delivery

I used oversized 00awg pure OFC wiring across the whole system. I replaced the alternator to battery positive cable and ran the same to the amplifers to ensure maximum current transfer and a future proof upgrade.
I also replaced the terrible earth strap which causes a lot of problems on this vehicle and the small gague wire from the chassis to the gearbox, i really want to run a cable direct from the alternator chassis to the battery ground and from there back to the amps, this will ensure the same capacity is available on both supply and return across the whole system with zero bottlenecks except the alternator,

I will at some point have to increase the capacity, being the alternator is at the back of the engine i can see enough space for the possibility of a dual alt setep in the future, i have a whole range of high power alternators that i can try out, im thinking another 90-120A should cover any future needs.

Positive wiring to alternator and amplifiers

I manged to get to the alternator under the car and reaplce the quite small gauge wiring to the positive post on the battery, i left the original wiring to the starter motor and cut off, secured the open end safely and cable tied it at multiple points to secure it in place.

Ground wiring to the chassis and gearbox

Here you can see under the battery tray where the negative post connects to the chassis leg providing the main return point for all negative connections across the car, I also went ahead and replaced the strap from chassis to transmision as a temporary measure to increase the capacity of the retun from the alternator through the gearbox and engine. i will eventualy as i said go direct from alternator casing back to ensure there is no bottlenecks in the current carrying capicity of the system. Just look how crusty that earth strap is! That’s where people have a lot of issues with thir Fiat/Abarth 500’s

Temporary fuse holder

I made this temporary ANL fuse holder untill i get round to upgrading the system, its safely tied down and isolated using multiple wraps of self amalgamated tape, tessa tape and some plastic caps over the top.

Noise control

To save weight and cost I always measure the cabins noise floor, This gives me a base measurement to work from, I take measurements stationary and driving in different locations to make sure both ambient and engine road noise can be accounted for. I use a calibrated microphone so I can compare spl levels before and after applicating noise control products which tells me which areas need more attention and which have reached their potential.

I use sound deadening to treat large thin panels on the bodywork these usually have a higher pitch ring when knocked on and vibrate, These bitchumen based products work by adding mass to the panel and lower the resonant frequency (pitch) of the panel, by reducing it low enough you can generally bury the vibration and noise produced in the bass region. By lowering it, it also makes it hard to locate, frequencies below 125hz are generqly harder for the ear to localize accurately this again blurs the vibration into the background and masks it. This is the initial stage for the boot it will undergo testing.

Note 1:
I had to insert some acoustic foam between the enclosure and the wheel well to futher reduce some vibrations tranmitting through the enclosure into the sheet metal.

Note 2:
I’ve noticed a huge increase in road noise coming from the rear quater panels and rear wheel arch areas, this will be the next areas i tackle whilst removing or replacing the rear speakers.

Front doors

I plan on making some custom enclosures once i decide on what to do in the rear quaters, Read below to see what i have planned for those!

For the front doors, if i plan to keep up with, and balance out the rear end i have planned out then ill have to at least fit a pair of 8″ of three 6″ to have the grunt to maintain balance upfront and a forward facing image across the dashboard. Seeing as the abarth has HUGE A pillars so i will definitely try to fit a full range mid in there, im aspiring to create some kind of waveguide up the a pillar as its massive enough to fit most any 3″ or 4″ driver and some kind of guide up the pillar replaceing the OEM a pillar trim.

Rear quaters

I have an idea of using the current 10″ JL WxV2 subs that are in the boot now, Install them in custom tuned enclosures in the rear quaters and upgrading the rear subs to the 12″ version of the same model. Id run the 12″ WxV2 upto 60hz then let the 10″ take over to 150hz, as long as i make sure the doors can keep up with the amount of rear fill this will cause then i should be able to balance the system out.

Boot floorpan

Tweeters

Midbass

The midbass for the front doors will be have to be a multidriver configuration to have enough cone area to keep up with the rear end. I estimate at least three 6″ or two 8″ drivers to 25cu inches to 31.1cu inches roughly taking a average 12mm xmax the difference between the two will be down to fitting three 6″ being much easier but id rather have the larger cone area of the twin 8″, they will need to be able to work in a small enclosure, a maximum of 20mm xmax to minimise woofer reach into the side of the driver and passenger seat, a minimum of 12mm to achieve the desired displacement nearly 5000 cubic inches

Subwoofers

The subwoofers are a pair of 10″ JL Audio WXv2 each working in close to a cubic foot of volume per driver in a sealed enclosure. Im using a pair of old school Vibe audio 4x110wrms class AB amplifiers, Even though i could run this entire systme on just one amplifier im installing two so that i ca considering running an active 3 way at a later date

Concepts and 3D sketches

I started out with this idea in mind, having the amps flipped over with the guts on show through some perspex, i wanted to build inserts that could be placed over the subs and amps so that you end up with a completely flat floor ready to carry anything and keeping everything functional and protected.

Fabricating the enclosure

The plan was to keep as much of the boot space as possible, so building the subwoofer into the wheel well meant i could keep the overall height fairly low, I can also bolt down the enclosure using the original mounting point for the spare wheel, its also wedged and locked into place tightly against the rear bench frame, it doesnt move at all even with some force applied so its very secure.

Fitting Amplfiers

Measuring and tuning

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