beginers guide to car audio...

[Bri]

Re: beginers guide to car audio...

Definitely a lot of reading to sludge through there. It would be nice to see something more tailored to smart fitments as your really gonna struggle to fit a tuned sealed box for even an 8" sub in any smart with out loosing much needed space unless a disco on wheels is your after and unless you go for custom door builds your stuck with finding better quality to fill the standard space, but thats no issue as theres plenty that do the job from JBL, Alpine etc..
That said for any one that hasn't a clue where to start as far as an audio install goes there is a terrifying selection of choice out there and any unbiased help in the right direction is good

[davros7760]

Re: beginers guide to car audio...

I think this information is far too valuable to be left in this format - for a start could the moderators make it a sticky so its permanently easily accessible in the ICE section?

Any suggestions as to how it could be made more readable - layout wise?
Obviously Sidle went with what was available i.e spreading over several consequtive threads

I can well imagine people using it as a reference document and it will get niggly

[Duncan.e]

Re: beginers guide to car audio...

Thanks for the info!

Much as I hate to admit it, sound quality is not a huge issue for me as my hearing is shot. My hearing frequency response drops off very rapidly above 2KHz and I have to wear hearing aids to rectify this deficiency.... Don't get old!

[NeilP]

Re: beginers guide to car audio...

Great info, very helpful! But now I have a question....

I'm considering throwing my standard stereo away and replacing it with a 7" Android tablet, using it as a sat-nav, to run Torque - an app which gives a digital dashboard from the OBD port via bluetooth - and finally as a music player.

My question is: The output from the tablet will need to be interfaced into an amp, will I need some form of pre-amp to match the tablet's speaker output to the amps input?

Thanks!

you can use something like a hifonics HFEQ to take care of that, although you won't have the best quality (as you're going to use the tablet's internal DAC - digital audio converter)

specs on the link...

http://www.soundevo.co.uk/shopexd.asp?id=309

[Duncan.e]

Re: beginers guide to car audio...

Great info, very helpful! But now I have a question....

I'm considering throwing my standard stereo away and replacing it with a 7" Android tablet, using it as a sat-nav, to run Torque - an app which gives a digital dashboard from the OBD port via bluetooth - and finally as a music player.

My question is: The output from the tablet will need to be interfaced into an amp, will I need some form of pre-amp to match the tablet's speaker output to the amps input?

Thanks!

[NeilP]

Re: beginers guide to car audio...

that is a fantastic read!

if only every customer I had to deal with could have some knowledge of what was written there, it'd make my life so much easier!

one addition (if i may) would be audison's bit 10 to the line out convertors/eq's as it is dedicated for high level inputs.

Cache also have a number of line out converters, all of which have outstanding low level output voltage!

nice read!

[problemchild1976]

Re: beginers guide to car audio...

thank you kind sir....

don't need the links unless you are planning changing your photobucket links in the near term

JJ

[sidle]

Re: beginers guide to car audio...

you may. will you require the img links??

[problemchild1976]

Re: beginers guide to car audio...

EXCELLENT - well done that man!!

please may i utilise this info on www.forfour.co.uk

one point - no where did you mention using my dad's massive sony hifi speakers and filling the boot of my daihatsu charade with them to get some free good bass

JJ

[sidle]

Re: beginers guide to car audio...

And finally

Disclaimer: I am a professional, and I am an Expert (i do this for a living) but im not the one working on your car.... I'm also not affiliated in any way with the links or products mentioned in this guide.

I have written this guide because I wish someone else had written it and given it to me 10 years ago. I would have saved me some costly mistakes and some stupid errors. This information is "The Received wisdom" if you like, the combined and generalised advice that many people have offered over the years.

Unfortunately, people get tired of typing it over and over again, so I thought I'd put it all in one place, as a port of call for newcomers to crystalise their ideas, review their expectations and get bang for buck from every pound they spend on car audio equipment.

I hope that it is take in that spirit.

This is not a "my way or the highway" post. We all experiment, it's what we do, and should do to keep improving. But you must walk before you run and this guide is intended to get the newcomer off all fours and toddling along FAST. That said, any errors, omissions or just plain lies in this guide, let me know by PM and I will edit them in! Cheers, .

[sidle]

Re: beginers guide to car audio...

Glossary of Terms:
EQ – Equaliser. A box of tricks or a setting on the head unit to boost/cut certain frequencies to make the sound balanced and natural.

SQ – Sound quality is paramount. Staging, imaging and tonal accuracy are the goals.

SPL – Sound pressure level. Competition cars designed to get the most air pressure whilst playing sub-bass. LOUD is king! Also the slightly less competative Street Bassers fit in here.

SQL- Sound Quality, Loud. Some people want the best of both worlds, Good sound quality at a volume that can be heard in other countries. SQL is the result.

TA – Time alignment. A digital process whereby signals to certain speakers are delayed by fractions of a second to overcome the different distances they are from the listener within a car. Not to be confused with “Traffic Announcement” settings which interrupt the music with tales of how dull the M4 is today.

Crossover - A box of electronics that takes a signal and divides it up, sending higher frequencies one way and lower frequencies another.

Passive System – A speaker set up where crossovers that receive no power of their own filter the signals to split them between tweeters and woofers. The crossovers sit in the signal path after amplification.

Active System – A speaker set up where a crossover divides the frequencies prior to amplification. Each speaker has it’s own dedicated amplifier channel.

2-Way System – A speaker set up consisting of a tweeter and a woofer on each channel.

3-Way System – A Speaker system consisting of three separate drivers – Tweeter, Mid-range and Woofer.

Co-Axial Speakers - A Set of speakers with a shared centre line. Normally a woofer with a tweeter mounted in the middle.

Component Speaker Systems - A speaker system comprised of separate parts, usually a woofer, tweeter and crossover all separate.

[sidle]

Re: beginers guide to car audio...

Some generic advice:

Set a budget and stick to it.

Listen to well set up cars to understand how they sound so good, and perhaps how you could improve on them.

Listen to badly set up cars to see why they sound bad and how you can avoid the same pitfalls.

If in doubt – ASK!

Keep safety in mind. You’re playing about with high currents and fire can be the result.



Some notes on car types:

Saloons, estates and Coupes tend to be relatively easy to put a basic install in. The same holds true for hatchbacks and people carriers as well as luxury 4X4’s.

Convertibles have a host of problems associated with being louder to start with, and having (generally) a sealed boot and fitting a subwoofer can be problematic. Getting a system to sound good with the roof down and the car moving will require serious attention to detail.

Sports cars tend to be limited by space within the cabin and their light weight ethos.

Classics may not have had speaker mount points and tend to have little if any deadening. Minis, Landrovers and MG’s have all been fitted with fine Audio systems, but they require a serious amount of work and more likely than not some fabrication skills to make speaker enclosures and amp mount points.

Modern cars are more and more often being supplied with integrated sat-nav and vehicle information screens. These can pose a serious problem to the DIY audio enthusiast, simply in obtaining a clean signal to amplify. It may be that retaining the OEM “head unit” and adding a processor such as the Audison Bit One, JL Audio Cleansweep or JBL MS-8 may be the expensive and only option in some cases. See owners club advice

[sidle]

Re: beginers guide to car audio...

Here is a simple system diagram of our basic install:



From this hopefully you can see how it all fits together. This is what we'd call a "3 channel system with a 2 way passive front end". This is a system diagram of what i first ran, and I have to say it sounds pretty sweet.

Of course, there are other system designs you can try:
This system has 4 channels and feeds full range signal to a pair of coaxial speakers. I would expect these speakers to be mounted in the rear doors in a normal set up.


Or how about an active set up?
Here we can see that each speaker i.e. each tweeter and woofer has its very own amplifier channel.


This system as shown would rely on either the head unit or amplifier having flexible enough crossovers built in to filter out the frequencies not suitable for each speaker. It also lacks a sub woofer channel – the 4 channel amplifier will not support this system alone.

Therefore, the system map for a viable active system will look more like this:



Here we see that an active crossover takes over the duty of splitting one stereo RCA input from the headunit into three pairs of outputs for amplification. A mono sub amplifier has been added to drive the subwoofer. (Note I have omitted some of the remote wires and the power supply for active crossover and mono amp for simplicities sake!)

You will note the core of these systems is the same. You can use the same 4 channel amp, Sub, and parts of the component speakers and even the head unit in all configurations as your system expands and improves. Hopefully now it is clear why the standard advice to buy good equipment is sound. Well bought equipment re-usable in new systems.

So hopefully now you have a better idea of how you can approach your first install.

[sidle]

Re: beginers guide to car audio...

Sound deadening:
A cheap pack of a self adhesive sound deadening product will be quick and easy to cut, shape and install in doors, floor pans and other large resonant panels. The bare minimum is to deaden the outer skins of your doors, essential if you’re putting 6 ½"s in there. If you have the choice of £200 speakers or £150 speakers and £50 on sound deadening, then get the deadening and the cheaper speakers. You’ll win out every time. Deadening has been done to death on this and other car audio forums so I’m not going to labour the point other than to say, do it, you won’t regret it!

"OK! I've got a huge pile of kit and an empty wallet! Let's get it all in there! I wanna hear the music!!!"

So you’ve bought the basics. You’ve got a head unit, a 4 channel amplifier. You’ve got a Set of nice 6 ½” front speakers or 5 ¼ ‘s at a push, and you’ve got a big wedgy MDF box with a 12” sub installed in it…. How do we fit this stuff to best effect?

It’s quite simple, but finding and running cables along the car tends to be the biggest pain. A close second is removing trim such as door cars to gain access to speaker mounting locations. Running cables into doors and through bulkheads is often the most challenging so see if owners clubs have any specific tips on routing. Often Right Hand Drive cars have a set of holes in the bulkhead on the left hand side where brake cylinders and clutch cables pass through the bulkhead in the continental model and it is wise to make use of these. If you intend to drill or use self tapping screws then CHECK before you do so. A drill bit or screw into a fuel tank, brake line or wiring loom will be very expensive and time consuming to put right.

Routing Cables
Conventional wisdom dictates that you run power cable up one side of the car, RCA and signal cable up the middle (as that's where the head unit is) and Speaker cable down the opposite side of the car from the power cable. In reality this is rarely possible. So long as you can maintain a separation of 5cm or so between the signal, speaker and power cables you will not pick up and nooise form one to the other. It is worthwhile knowing where ECU's and other complex electronic items in your car are (ie. airbag ECU's, Fuse boxes etc) are and routing all cables well away from these. They tend to kick out high frequency interference and coils in crossovers may well pick that up inroducing noise to the audio system. Only by examining your car will you work out the best route for your cables.

[sidle]

Re: beginers guide to car audio...

Wiring it all up:

You need cable to send signals from the head unit to the amplifier, and get the amplified signals from the amp to the speakers.

"Damn! This cable is expensive. how much should I spend?"

Power supply:
You DO need to invest in decent power cable to run your amp. Car audio systems operate at high power but low voltage, and this means their current draw can be insanely high. A powerful amplifier might draw 100 Amps at full load – Even an electric Kettle only draws 10 Amps! Voltage drop also occurs over distance, and your amp might be 4 or 5 metres of cable away from your car battery. Voltage drop forces the cable to carry even MORE current, heating it up even more and increasing its resistance… this is a viscous cycle. This means that you need the thickest copper power cable you can afford, End of story. Realistically 4Awg (4 gauge) is a minimum for any amplifier of acceptable power output. If you start exceeding 1Kw total power draw, it’s time to upgrade to 2Awg or even 0Awg.

This power cable MUST be fused. Not should, not “it would be nice”… This cable plainly and simply MUST be fused as close to the battery as physically possible. This is not to protect the amp, it can take care of itself. This is to protect the cable itself.

The problem with a car electrical system is that the entire vehicles body is a ground and connected to the negative terminal of the battery. And you’re taking a length of cable, and passing it through sharp metal bulkheads and lying it along the cars chassis with nothing more than a couple of mm of insulation and a lick of paint between the +ve and –ve sources. Let’s say for example that a sharp metal edge in the engine bay cuts your insulation on your power cable and then contacts the conductor within. Here are the two scenarios:

Fused: Your battery is short circuited and begins to supply as much current as it can down your poor cable. The heat at the point of the short circuit is so great that it actually welds the cable to the bulkhead, making the connection firm… the battery instantaneously supplies 600 Amps down the cable, things get red hot, the cable insulation starts to melt… and the fuse burn out, breaking the short circuit. Oh, and your amp stops working until you’ve repaired the cable and replaced the fuse.


Unfused: The first part is the same, the battery begins to supply 600amps into the short circuit. The cables insulation does begin to melt though, and in fact gets so hot it sets itself on fire, catching with plastics and fuel in the engine bay. There is no fuse to blow, so the fire takes hold. Your engine is toast by now, and if you’re driving you’ve got about 10 seconds to pull over and get out before the cabin is filled with acrid smoke. You get to watch your car burn to the ground, which is kind of cool if you’re a masochist. Oh, and your insurance probably won’t pay out after their investigators find out that the fire was wholly due to your negligence in fitting a 4awg cable directly to your positive battery terminal without a fuse.



So for power supply, you need a thick cable, and a fuse holder and fuse, and you need some ring terminals to make a good solid connection to the amplifier and battery.
The Ground should be equal in gauge to the supply, and should be grounded as close as possible to the amplifier. You should ground to bare metal and secure it. A huge number of problems with noise in audio systems or amplifiers being unreliable or not working, are due to inadequate grounding of the amp.

For signal
You will need a couple of RCA cables. To go from the front to the rear of most cars, you will need them to be 4-5 metres long, or you can make your own easily using plugs and cable from places like RS or maplins so long as you know which end of a soldering iron to hold. You can spend a lot, or you can spend a little. £10 a cable should be enough to get them to be good quality and durable, and that is all you really need.

Speaker cable
Speaker cable is also important. It should be copper, and it should be sufficient diameter to carry high voltage signals a few metres without appreciable drop. 16Awg-12Awg should be more than adequate for most applications. £1 a metre would be an acceptable upper limit on the amount to spend. Are you going to notice the improvements in spending £3 a metre on the finest copper cable known to man? I would argue that you’re in a tin box doing 70Mph on the M6 toll road and you should not waste money by buying audiophile grade cable to run along the floor pan of your car….
Your remote wire can be any old length of wire. It literally carries a 12V signal to power up the amp. Some RCA’s have a thin strand of cable in the middle to perform this function and I would make use of this. Alternatively, you can use a length of speaker cable. You can use the +ve strand as your remote wire, and the –ve strand can be used to reinforce your head units ground by connecting it to amplifier ground, to eliminate noise.
Amplifier wiring kits are available and offer a bundle of cable, a fuse holder and some signal and speaker cable. They can offer a cost effective way to get what you need, just check the lengths supplied meet what you need. If you’re not going for the standard “Amp in boot, Head unit up front” install, or your battery is already in the boot, you may be able to make savings by buying cable off of the shelf separately.