Showtime

I'll admit it..I'm an Ice Idiot..

i want to upgrade the speakers, (MY96 STi)but dont know what is a component speaker, whats a 2 way or a 3 way, whats passive crossover??. All greek to me..

Do I really need an amp or will better speakers off the head unit do the job..any suggestions of what to put in for about £150/£200

Thanks and be kind...I'm sorry for being dim..

Lee

You're probably better off visiting your local ice dealer then tim-nice-but-dim

for the sort of money you're talking about you could afford head unit OR speakers OR an amp.

presuming you have the std setup its a choice between head unit or speakers.

My personal preference would be the head unit, however some have disagreed and think the std speakers are the poorest part of the system.

Have you any mates who could lend a decent head unit so you could find out first ?

Showtime

Thanks Lee, I've changed the head unit anyway and put in a single CD player. (only a cheapy while I save up for a decent multi CD/Minidisc. Speakers are very low quality, so I want to spend the 200 quid on the speakers. I've seen some good deals on JBL's components (a la' max power adverts) and fancy a pair of MB-Quart 6 X 9's for the rear.

I just didn't know the difference between 2 and 3 way and wanted to know if I can wire them straight in.

Thanks for your input (no pun intended)

Lee

Yes you can sort of wire them straight in..

since you are not using amps the speaker cable that is already present will do the job - although audiophiles change it along with everything else !!

a 2-way speaker (aka Co-ax) has the tweeter in the middle of the larger cone. Thus it is a single speaker which produces sound. The frequencies are crudely chopped by a resistor usually (built into the speaker casing)

a 3-way (aka component) has a separate tweeter which can be mounted anywhere. (This can give a better sound) they also come with a "passive crossover" which separates the midrange from the treble..sends the treble to the tweeter effectively.

whichever you buy you'll take the standard speaker wiring from the head unit into the door and you'll either wire straight to the speaker (2-way) or the crossover (3-way).

only possible catch-you-out with speakers is their physical size compared to the standard ones and amount of space in the door. You need a speaker with less than 74mm of magnet/basket depth to fit and you may need to make up some spacers to avoid the speaker rears hitting the glass.

Adam M

Sory Lee, have to disagree with you on almost all points.

Two way just means it has a tweeter as well as a woofer (or mid bass/mid woofer).

Three way means it has a separate woofer, mid and tweeter.

Coaxial just means that the drivers are mounted on on the same axis ie. small in the middle of big. Sometimes they are not exactly in the middle but offset as there isnt enough room e.g in a three way coax it is difficult for all three to be mounted on the same axis.

Component means all the speakers, 2 or 3 (sometimes 4) are separate and need to be mounted separately.

In the industry, a component speaker is normally the most expensive and has the best power handling, this is because it can have a larger magnet and more circulating air.

In theory however the sound is best when coming from the a single point and this is only really achievable with a coax speaker. The best would be a high power handling coax with good heat dissipation but it is a trade off unfortunately.

Crossovers are just used to separate the sound and protect the speaker from frequencies it can't produce.

Cheaper units have just a capacitor on the positive terminal of the tweeter, this is because at higher frequencies a capacitor conducts electricity but at lower frequencies it does not so bass cannot get through to the tweeter. This means that high frequency does still get through to the woofer but this does not matter as the small currents associated with high frequency are not enough to move the mass of the cone fast enough, so it is dissipated as heat in the coil of the woofer.

A capacitor can be used to cut treble from a woofer by placing one across the terminals. In this situation high frequency simply conducts across the terminals and effectively short circuits the output of the amplifier. Again due to the low power it does not matter.

A crossover is merely a separate box which has two inputs pos and neg. It does what I have described aboved but inside the box and has outputs for each driver (regardless of how many 2, 3, 4.....)

It does get more complicated than this as you can change the effectiveness of the crossover by adding inductors (long coils of wire), and changing the layout. This will change the slope of the crossover. This refers to how steep the cutoff point is. Crossovers do not switch off frequencies above the cut off point they merely attenuate them, the slope simply defines how fast they attentuate them and so is measured in volume decrease/change in frequency.

Sorry if it looks complicated but with this in mind everything else becomes easier when designing systems.

If there is anything I can throw some more light on then just ask.

[This message has been edited by Adam M (edited 23-02-2000).]

Lee

unlike your post mine was designed for the target audience

I'm sure he means coax/components ..yes I do know what crossovers do but showtime did ask for an easy answer..i'm sure you've left him reeling

need to speak to you at some point...

Adam M

Lee,
its not that I was explaining stuff to you, that was for everyone else and was supposed to be understandable for everyone.

My problem with what you was your definition of two and three way. It isnt true. see the clear statements I wrote above before I went off on one.

Forgive my enthusiasm.

Lee

<g> forgiven <g>

AlexM

Hi All,

Just to confuse Showtime even further

Coaxial speakers have theoretical advantages in Stereo imaging as they come closest to approximating a point source. There are also other multi driver configurations which also approximate a point source - they are more common is domestic and professional HiFi, but you tend to need to be further away from the speakers to allow for proper integration of the driver's output.

The theoretical advantages of a coaxial configuration for ICE applications are undermined in most cases by the mechanical arrangement of the tweeter pod, a mid-range suckout caused by cancellation reflections from the tweeter pod, and last but by no means least, my leg being directly in front of the tweeter when it is in the kick panel or at the bottom of the front door .

As far as I know, only KEF make the only truely cooincident coax driver design because they have managed to design a tweeter small enough to fit inside the midbass driver's pole piece. Tannoy also do true coax drivers with a central horn tweeter arrangement, but at 12"-15" they are probably a bit big for most ICE installations .

Having said that, Adam has some pretty nice sounding coax speakers in the front of his car so he's probably right after all (adjustable tweeter level?).

Cheers,

Alex



[This message has been edited by AlexM (edited 24-02-2000).]

pilch

Not meaning to side with anyone or say you are wrong, but from my experience the 2-way means there are 2 distinct speakers in one unit (tweet plus mid usually) and 3-way is most often a bass plus mid, with external satellite tweet (Showtime - this means you mount the tweeter somewhere away from the main speaker, like on the 'A' column in front of the door). I have 2 sets of JBL in my MY94 WRX; 2-way mid/tweet in the front door, and 2-way mid/tweet with satellite tweeter in the back shelf. Yeah, I know, I need to rotate them! I haven't cracked out the rear tweets yet Before you flame me, yes, I have a sub in the boot. I'm gonna get a custom made side-mount
Getting back to roots; Showtime, I replaced the head unit first with the best unit I could afford (Pioneer 7000 series) which cost £300. It is now around £200-£250. This made a HUGE difference! Then the speakers were popping, so they went. The fronts first, then the back. The back ones were actually good from stock, but I wanted clarity, so I used good mid-range all round and the external sub. The Pioneer head unit has a HPF (High pass filter, cuts out the bass) and external amp support. Great sounds! The bass sub don't handle the power, and I don't have amps for the mid/tweets.
The choice is yours, but I recommend just using the front for now, disable the back, get a sub in the boot (£175 for the custom box/12" speaker, amp extra). This brings us to the debate of whether rear speakers are worth it! 6"x9"s anyone? Heh!

pilch

Adam M

I will stand by what I have always said, dont waste money by buying rear speakers in the first place, put all the money into head unit and front speakers. You can buy some excellent coaxs if you can justify them. They are almost as good quality wise as components (separate speakers) but have true singe point source.

eg. caliber
orion
focal (expensive)
JL (expensive)

I hate to say this but I would try to avoid JBL. They tend to sell on their name which was established in home cinema and pa systems. They have officially independently withdrawn from car audio so their products now are simply other peoples rebadged products. Saying the that the best subs I ever owned were four JBL GT8s.

Showtime

Er.right, No thanks guys, I appreciate all the comments here, I wanted to get some background before visiting local Ice dealer so didn't get stitched up with something I didn't want.

Most speakers on offer all seem to be pretty good, with the emphasis on paying as much as poss for fronts and head unit. I'll start there and advise progress when I start installing.

I've at least got some 'SOUND ADVICE' then

Blow Dog

LOL showtime, very good!

hehe
PS. lemme know what speakers you gonna get for your fronts. I may aswell replace the fronts.
Cem

Showtime

Hmm..Been into Halfords of all plces and they are doing a deal on speakers, buy one set get 2nd set for half price. Seems good, so I was looking at some Panasonic 140W components (13cm) for 85 quid, but couldn't decide on rears, alpine kenwood or pioneer, all seemed good to my (inexperienced) ears.

Should I go for any of the above or stick with the Max' adverts and get some JBL and MB Quarts ??

Also, I have to ask Lee/Adam, what actually makes a standard speaker distort, and what is it about the 'quality ones' that makes them better...just curious whilst I'm here

[This message has been edited by Showtime (edited 26-02-2000).]

Adam M

do not buy them. Do not buy rears. put all money in fronts, and not panasonic.

Max power ads are alright, normally cheap. Up to you.

Not what I'd do though but your choice.

Can try to get you some independent American makes, such as soundstream, phoenix gold etc, possibly cheaply as they are b stock.

Would be a better bet.

Mail me offline if you like but do not go to halfords.

Nick Lines

<BLOCKQUOTE><font size="1" face="Verdana, Arial">quote:<HR>Originally posted by Adam M:
<B>
A capacitor can be used to cut treble from a woofer by placing one across the terminals. In this situation high frequency simply conducts across the terminals and effectively short circuits the output of the amplifier. Again due to the low power it does not matter.
[/quote]

I realise that this is pedantic, but I want to check my understanding as it could be wrong. A capacitor is a high-pass filter, allowing anything above a certain frequency to pass to the speaker, so is used as a simple crossover for a tweeter. An inductor (coil/whatever) is a low-pass filter, allowing anything under a certain frequency to pass to the speaker.

To cut the treble from a woofer, or indeed to cut mid-range from a sub, don't you need an inductor (opposite of a capacitor)

The design of a woofer inherantly limits high-frequency reproduction, but inductors are still useful to ensure a smooth transition from one driver to the next.

Whilst on the subject of crossovers, it may be useful to know that there's two types: active, and passive. Passive crossovers work on the amplified signal (require no power source, hence passive) whereas active crossovers work on the signal before it has been amplified. As a minimum, it is recommended that you use an active low pass crossover for your sub bass: most amps have this, and the feature is starting to appear on lots of head units. (Kenwood System E+, for example). The reason for this is that you're not wasting amplifier power in heating up a coil on the speaker... Another useful feature for the head unit is the ability to filter out low frequency from your front/rear speakers: again, the Kenwood system E+ thing does this. Benefits are that it saves your front speakers from trying to reproduce extremely low frequencies that they cannot play.

Ramble mode now disengaged. Good luck!

Nick

Showtime

Adam,

Will mail you !!
I didn't buy anything at the weekend, did visit sound city in worthing, but expensive !!

AlexM

Nick,

You're almost right. However, most 'proper' crossovers will use an LRC network to get the appropriate band-pass characteristics for the drivers used.

Debates rage on endlessly in the Audiophile press about which is the best approach - a simple crossover which is more efficient, and sounds 'clearer' to some in conjunction with drivers which are designed to roll-off smoothly at their frequency extemes, or a complex crossover network which tailors the frequency response of the drivers to integrate their output smoothly.

There are very good examples of both, e.g. Spendor/Harbeth BBC monitor type designs use very complex crossovers and are very neutral (+-2db from 100hz - 12khz) or simple designs which may be less neutral in terms of frequency response, but are said by some to have better dynamics.

In ICE applications, active crossovers are preferable because they improve the efficiency of amps and speakers, and are more flexible in terms of tuning the output. Reducing the 'out of band' signal to a speaker increases its power handling as it won't waste cone excursion trying to reproduce frequencies below it's operating range. Most subs are acoustically loaded to limit cone excursions for out of band signals.

Cheers,

Alex


[This message has been edited by AlexM (edited 28-02-2000).]

Adam M

Nick you are missing the point.

A capacitor effectively conducts at high frequency. Therefore depending on circuit arrangement it can used as a high pass or a low pass filter. Coils conduct less at high frequency as the inductance of the wire opposes the change in the current through them. This opposition is a function of frequency therefore, the greater the frequency, the greater the resistance.

You can therefore use a coil (or inductor) as a low or high pass filter depending on the circuit diagram.

Coils are used generally for low pass filters on subwoofers as they are more effective at dissipating heat, than a capacitor.

Both are used in crossover design and combinations and layout as mentioned above allow you to alter the slope etc.

To anyone who missed it by the way, a bandpass filter lets through the bit under a high pass filter and over a low pass filter. Eg. could be used for a midrange which does want sub bass or treble.

Anything else?

Adam M

Oh yeah, and before someone picks me up on it, I know that it should be reactance as opposed to resistance when talking about AC signals, but I didn't want to confuse the situation further.

Lee

Yeah..likely someone's going to start picking holes in that lot

**** me, every other word is a mystery..you guys should have interpreters..

Jonathan

Adam

I sell Filters for a living and that is one way to describe a bandpass that Ive never come across. Not sure I'd get my salesforce to use that as a way to describe what they are selling.

Highpass does not mean by definition it only passes high frequencies just frequencies above the stated cutoff frequency. A lowpass the other way.

Maybe a spectrum analyser response would help show the differences

Jonathan

Paulie

[Lurker filter finally off!]

Hi Showtime (and the rest of you...)

You mentioned MB Quart speakers - I've fitted a pair of MB Quart DSC216's in the front of my MY98 and they sound pretty splendid (through my old-school Alpine 7525), considering they were cheap (£80 tottenham court road).

The only pain was having to get my junior hacksaw out and carve up some mdf ring spacers to stop the (sloth-like) windows from banging against them (and yes, I only found this out the hard way )

Adam M

Jonathan,

I would appreciate your sales definition of what a bandpass is, perhaps I have my wires crossed.

I dont know who your definition of a high pass crossover is supposed to have come from but it isnt mine, I assume you mean me as the post is addressed to me. I made som specific references to slopes which directly imply that the cut-off of a filter is not a cliff more the top (or is it middle) of a hill.

Hope you can put me straight re: bandpasses.

Thanks in advance,

Adam

Showtime

Hey, Thanks paulie..I'm off to tottenham court road then, good advice as I'm in town next week anyway..

Paulie

If I remember right, the place was 'Hi Way Hi Fi' - smallish shop with an ICE section at the back.

Then again, the whole street's a cartel, so the prices are pretty much the same...