50 replies to this topic

[Crowson_punk]

Sound staging:

I've worked as a sound engineer for a while now, and bad staging in cars (unfortunately including my own...) is a major bugbear of mine!!!

Lets look at the average sound set up in a mini:

Under the seats most people fit 6x9's the reasons against them have already been covered for parcel shelf fitting, but under the seats is a very bad place for speakers. Mainly as most of the speaker boards point down towards the floor in my experience and that is silly! What it does is bounce the sound off the floor and into a random pattern towards your ears, completely diffracting the stereo image the music's producer spent so long getting right!!!

Then, we move onto the rear shelf speakers, rear speakers as has been said tend to be a bit fuzzy in ears due to them facing the wrong way! But on top of that I often see minis with them pointing at the back window... Surprisingly this does the same as a board pointing at the floor/back seats.

Front speakers I've seen mounted in several ways, but for now, we'll assume they are in the door pockets. Most aftermarket and home build door pods point the sound straight at your shins! As above with the back shelf etc

Hear we can see a rough guide (yes the angles look wrong and aren't accurate, so please take them as a very quickly cobbled together paint picture, to very roughly demonstrate the principle,) to the path the sound takes from the average install:



As you can see, the sound has no clear path to the centre, where a stereo image is centered. it's one of the reasons a film always sounds better at a cinema than it does on your home surround sound as nobody ever gets the picture right lol. The front speakers that are aimed at your shins actually cancel certain frequencies out of each other as they both point directly at each other!!! I have this in my golf at the minute and its damned annoying. (i'm just too skint to do owt about it!)


The best designed builds tilt the speakers towards the top centre of the car, as thus;


As you can see i've ignored the back seat passengers, as they don't matter, they'll always mangle the stereo image no matter how hard you try in a mini lol there just isn't the space!

So we have in that picture, the tweeters at the front on top of the dash or attached to the A pillars, either or it doesn't really matter, Door pods with 6.5" (or mid bass woofers,) speakers pointing directly at a point in the car in between the front seats and level with the headrests, Then the pods in the rear bins with smaller speakers doing similar, only a little further back so as not to muddy the sound. They are usually a lot lower in level than the front.

Under the back seat we have a small 6-8", (ten if you can get on in, i haven't tried lol,) for the mid/lows and a 12" in the boot. I would usually suggest a sealed enclosure for the little 'un and a ported for the big. That gives you hard bass drops and tight, punchy mid bass. I find bass guitars and deep voices pop from sealed 8"'s really nicely!

So I'm sure you're about to ask "but if theres only you in ther car you'll get mostly the left in your ear anyway so it's all irrelevant!" and, I shall say, "thats what the balance control on the stereo is for!!!"

A few early 00's sony head units came with a one touch sound stage button, that could boost the volume to the side opposite the driver so it balanced the sound out. But i'm guessing they dropped it becuase nobody knew what it was for!!!!! On a poor build you'll find that you actually need to boost the side you're on as you mostly hear the left. In a well designed system the speakers on your side will be pointing at your head so will need the volume cutting a bit to even it all out!!!

Ideally you want the fader set to about 4/5 to the front to keep the levell of the backs at a background. The main problem with doing this is a lot of headunits only have front and rear amp pre-outs meaning you're sub will go quite with the back!!! To combat this always make sure the headunit has a seperate subwoofer amplifier out, as it saves you having to buy line level controls to distribute the signals! Any questions, feel free to ask!!!

Jon.

Edit:

I forgot to mention about surfacings lol. A lot of spl Installers fit fabric over the hard plastic/metal surfaces of a car. this isn't just aesthetic! It softens impact of the sound waves, and reduces distortion or fragmentation of frequencies you get from hard surfaces such as glass or metal. Insulating the floors etc has already been covered, so just remember that the aim is to place the sound where you want it BEFORE it has to reflect off anything. this isn't always possible and when you're in the car you are generally in the way!

Edited by Crowson_punk, 21 June 2010 - 09:48 AM.

[minilester]

very informative... but in your first picture even as a "rough" diagram the angles you present for the sound reflection are sooooo wrong and a little miseading to anyone who really is intrested in getting the sound stage right... not trying to start an argument, but but people will believe you to be right as you sound like you know what your talkin about. if you could just redraw that top diagram with chaotic angles that mirror the angle of attack on the surfaces it hits would be more accurate and not so misleading just to "prove your point" diagrams that are wrong gives people false knowlege on a subject they dont know to much about.

and the second section your suggestions for subs is way to generalised..

if you listen to house/garage/club music get a ported 10"sub
hip-hop/drum and bass/jungle/bassline/niche get a 12"-15" tuned
pop and rock 8"-10" will suite you fine but you'll need to play with tthe ported or non-ported boxes to find which works best for you

your speaker set up it self is ok.. but then all the stage it self needs to be set up fore the music gene you listen to aswel..


Lester

Edited by minilester, 20 June 2010 - 11:30 AM.

[Crowson_punk]

Well due to it not being a 3d drawing, it's hard to show when the sound heads towards the floor/roof/back window lmao

It's just a rough impression. I wasn't going to spend hours with protracters....

sound never bounces back dead straight as it depends on what surface it hits, windows give you a fairly soft reflection, with little bleed through and as a result it tends to refract like light does coming back off centre, metal gives you a distorted, "tinny" reflection thats often fragmented, carpet and headlining tends to trap a bit more of the frequencies but you get a fairly straight return..

it's not quite the same as playing squash, where you can aim a bounce perfectly.

I'll edit it to make this clear

I've been a bassist for years, and i've spent alot of time playing with amplifiers and setting speaker cabinets up so the size of a sub is proportionate to it's frequency range. If you play jungle through just a 15, you lose a lot of the tightness of the bass lines, and you only get the lows. Ideally you want one of each size with an e.q to send the appropriate frequencies to each. I find a compromise is an 8" for the actual Basslines and the 12" to handle the big drops and the kick drum. This honestly works for any music.

In my bass cabinet attached to my amp I run one 15" woofer, and another cab with 2 10" cones, 2 12" cones and a horn for the high "nuances" you get with guitars. This allows me to set my e.q so I have every note on my fret board covered. P.A systems are the same, a couple of big woofers and a selection of horns and speakrs of various sizings to handle the rest!!!!

Plus dance and house often doesn't have a proper stereo picture, it generally has centre sound and sounds that "ping-pong" from left to right, this makes it essential to get the picture correct else it spoils the effect.

Jon.

Edited by Crowson_punk, 21 June 2010 - 09:55 AM.

[Brams96]

Crowson - I dont disagree with your theory & I understand about the picture your trying to get across. You say your a bassist & sound engineer who has set up many speaker cabinets but unfortunately that doesn't mean it applies to car audio systems. Yes stageing is important but unlike big venues or halls etc in a car you can't have woofers & horn sets all set apart to give you the depth you need. You said:

'In my bass cabinet attached to my amp I run one 15" woofer, and another cab with 2 10" cones, 2 12" cones and a horn for the high "nuances" you get with guitars. This allows me to set my e.q so I have every note on my fret board covered. P.A systems are the same, a couple of big woofers and a selection of horns and speakrs of various sizings to handle the rest!!!!'

PA systems are a lot different than car audio & nobody can get all the different size speakers in their car to cover all frequencies like your bass cabinet. Mini's are a small environment with minimal trim unlike modern cars which are wider, better sound deadened & more spacious. Most people on TMF ask 'what speaker should I get' or 'where should I put my speakers' or 'what sub should I get', (you get the picture) so aren't all to worried about competition level SQ stageing or imaging they just want 'more power'.

To have a 12" sub in the boot & an 8" under the seat is uneconomical to most people and with the right front speaker selection you don't need the 8. Also rear speakers (most of the time) dont add anything to the front sound stage.

For a good sound stage all you need is a decent head unit, a decent set of 6.5" component front speakers in door pods & a single 10" or 12" sub all driven from an amp (or 2). Positioning & angling of speakers is more importent than having different size speakers covering 'all the frequencies'.

[Ruckus]

I never really spent any time reading though this thread/guide... the early stuff from Rob is very good and i agree with almost everything he says. And this is from both techincal and real world experience perspectives.

But the last few posts from this Crowson chap should realy be removed...

He is clearly not coming back after a huge 38 posts!
He Clearly does not own or has never had an audio install in a mini.
Thinks for some reason that PA/Large scale audio is directly relevant to a audio system in a mini?!

He is going on about speaker position and taking about cutting the volume to help the staging...BUT

• With the correct positioning in a car (every car is different) you can get a system that 'stages' for both driver and passenger.
• If your going to this much trouble why not use Time Alignment! (the Balance control is just a poor mans Time Alignment)
• If you adjust your balance and running a mono sub (as you should) then you are cutting volume to the sub as well.
• And he talks about cutingt the left channel? This is SO wrong it hurts! In a mini with front speakers if anything you need to Boost the left and CUT the right, as the speaker nearest you are going to naturally be louder, therefore pulling the stage that way.
• All these speakers and not a word of the correct set up of cross overs, which if done wrong would give frequency peaks all over the place which in turn will destroy staging.
• 'Mini, 'Rear speakers' and 'Sound stage' in the same sentence... really!!
• Does not mention phase problems due to speaker path lengths.

To be honest his point about firing the mids in to he car and up is mostly correct but that's NOT the best way to aim tweets. As there is no BEST way. Due to different tweeters having massively diffrent off/on axis response there cant be a defined right way
I have seen the following tweeters aiming work:

• Aimed to the middle of the car.
• Passengers side aimed a Driver left ear, Driver side aimed at Passengers Right ear.
• Aimed across at each other.
• Aimed away slightly toward the screen.
• Aimed at the screen.
• Aimed at the screen running out of phase.
• Downin the kick with the mids.

And this says nothing of actual install position, which again in the real world ive seen.

• Corner of the dash,
• In the front face of the dash at the sides.
• Mounted on the A- Pillar low
• Mounted on the A- Pillar Mid way up
• Mounted on the A- Pillar right at the top.

The biggest alarm to me that this user has little understanding of a real world system in a mini is the line about using the balance to fade the right channel in a right hand drive mini! Unless he got his left and right mixed up this tell me he is using the logical of large scale or home sound systems with on axis listening, single source point (speakers all in the same places) and no path interference.


Please everyone that's interested do your own research in to what I'm saying but for me 90% of what he says is not relevant.

Basically put the mids and tweeters up front and move them around until it sounds right to you, before you the commit to the instillation.
I know this is hard with the mids but its easy with the tweeters.

Simple

Edited by Ruckus, 27 August 2011 - 08:06 AM.

[Gingerpete]

Hi all, just after some clarification before I start my install.

I'll be going for a 8" sub in the boot with some fairly hefty 6x9s under the rear seats.

Anyhow, I was told on a previous car that the inline fuse from battery to amp should be situated outside the car(was then in the engine bay) having the battery and amp in the boot is it still neccesary to do this? Or is the inline fuse, situated in the boot ok?

Thanks in advance