Vauxhall Owners Network Forum banner

Omega speakers and ICE misconceptions

9K views 5 replies 6 participants last post by  Dave's Vectra 
#1 ·
Standard fit.
17cm front and 13cm rear. Pressed paper cone. Small, lightweight magnet and voice coil. They’ll handle around 20-30Wrms. Both front and back have a separate tweeter, which has a high pass filter (Simple capacitor to block bass). Their frequency range and performance are a bit limited, but they’re surprisingly good.

‘Custom Fit’ replacements.
These are designed to be a simple swap for the original speakers. They are more solid and have a slightly higher power rating. They are usually co-axial in layout, with all the noise producing bits mounted close together on the same axis.
They generally have slightly better performance than standards, depending on make.
They don’t usually need an ‘adaptor ring’ to be fitted and have several mounting holes round their edge to allow maximum compatibility. Several manufacturers produce them, such as Pioneer, Alpine and Kenwood.

‘Component’ replacements.
Usually consist of two separate drivers, Midrange and Tweeter. They are driven via a crossover, a little box of electronics, which separate the frequencies.
They have a much higher power rating than the other two types. The midrange drivers have stiffer suspensions and require a lot of power to make them move. Generally better performing than the other types. Normally ‘high passed’ and used as ‘Midrange’ speakers in systems with separate bass speaker.

‘6X9s’ replacements.
Often the speaker of choice for many aftermarket systems, they are an ‘all round’ speaker (no pun intended!). They have a large-ish ‘bass’ cone and coaxially mounted mid and tweeter parts. They are easy to fit and can have good overall performance. ‘Jack of all trades’, best describes them!

Subwoofer
Separate bass speaker, usually in the boot, as that’s really the only place it’ll fit, driven by separate amp. ‘Active’ subs have the amp and speaker built into one neat box, which can be removed from car reasonably easily.
Can be mounted anywhere in the boot, facing forwards, backwards or sideways. (However, subwoofer placement is a huge and complex theory in itself).
Requires a large power source. The amp should be the same or higher in power rating (rms values).

Popular misconceptions!

“Headunits produce 40-50Watts per channel.”
Not quite!

40-50W is a manufacturer’s quoted maximum rating, where supply voltage is unrealistically high, distortion is noticeable and amplifier life is limited. It cannot normally be achieved in a car.
Rms values should always be quoted. It’s a more realistic value that can be sustained under normal in-car conditions. Headunits, by their design, can only produce around 18Wrms per channel.

“A 300W speaker will ‘give out’ 300W”.
That depends on the meaning of “300W”
Quoted power is usually, unfortunately, maximum, not RMS rating, and under unrealistic conditions. Lesser manufacturers add up the power of each drive unit within the speaker to give a grand total!
The speaker will only ‘give out’ whatever is put in. Drive a 100 Wrms speaker with 50Wrms and it will produce 50Wrms.

“My speakers are distorting”.
Probably not!
You turn up the volume and bass, and all you get is a nasty rasping. That’s the headunit trying to output more power than it can. Remember, it’s only got 18Wrms to give. It can’t handle it, so it chops the waveform, which now resembles a square wave and sends it to the speaker, which tries to reproduce the wave. It can’t and the voice coil starts to overheat and will eventually fail.

“Standard speakers won’t handle the power of my new H/U”
They will! Remember, the rating of the new headunit is only about 18Wrms.
If the headunit is any good, the standard speakers should sound better.

“Speakers should go in the rear of the car”.
It’s a bit of a personal choice.
The best speakers should be at the front of the car. Just like a home Hi Fi or live stage performance, the sound is at the front. The rear speakers can be used to ‘fill in’ the sound. Speakers were traditionally put in the rear parcel shelf, as this has always been the easiest way to do it, especially using 6X9s. It is not the best for sound quality though.

“Replacement components will give me better sound.”
Not necessarily.
The only proper two ways to drive them is ‘high passed’ from an external amp or ‘full range’ from an external amp. In the first case, they will be used in conjunction with a separate bass speaker. In the second case, they won’t.
When driven from a headunit, they should sound clearer and have better stereo ‘image’, but the bass response may be worse than the standard speakers and the headunit will probably start to distort at a lower volume than it did before.

“Standard speakers are rubbish”.
Not nowadays.
Manufacturers now realise that a decent sound system can help to sell cars. Most car owners appreciate decent sounds, so the standard speakers are quite good and will sound even better if given a good quality, undistorted signal from an external amplifier.

“You can’t use a big amp on a small subwoofer”
You can if you’re sensible.
It is perfectly safe to use a 1000Wrms amp on a 250Wrms speaker, as long as the amp gain is set appropriately. It is better to have ‘headroom’, where the amp is easily able to provide the required output without distortion.
It is not good to use a 250Wrms amp on a 1000Wrms sub. The speaker will not be driven hard enough and won’t perform to its best, and there will be a temptation to turn the gain on the amp up and send the speaker a distorted signal, which will damage the voice coil sooner or later.
Even if a subwoofer is matched to an amp. properly, it can still be damaged if it is in the wrong type and size of box.

“Standard speaker wire will melt if I use an external amp.”
Not under reasonable conditions.
Most standard car speaker wire will handle 6Amps continuously. That’s equivalent to around 70Wrms. That’s far more than is normally needed for front component speakers running full range. If they’re high passed, the draw will probably be 35Wrms at the very most.

“The big fuse will protect the amplifier from overload”.
It won’t.
It’s there to protect the power cable. If the cable is shorted anywhere along its length right up to the fuse, the fuse will blow before the cable overheats and melts.
This will prevent a possible fire! The fuse must be rated at a bit less than the cable.
Amplifiers have ‘small’ fuses too. They protect the insides of the amp from overheating and catching fire under short circuit conditions.
 
See less See more
#2 ·
Bro i am new - and this is one of the most insightful pieces of reading on the subject - and clearly show me all the mistakes that i made when installing a new Sony bluetooth head unit and Infinity coaxials and infinity 6X9s - in my dad's 1998 Maxima i think it sounds horrible. But he is fine with it low volumes and all - but spent so much money for such a crappy result. Thanks mate Cheers.
 
#4 ·
Standard fit.
17cm front and 13cm rear. Pressed paper cone. Small, lightweight magnet and voice coil. They’ll handle around 20-30Wrms. Both front and back have a separate tweeter, which has a high pass filter (Simple capacitor to block bass). Their frequency range and performance are a bit limited, but they’re surprisingly good.
Hi, are these sizes the same on pre and post facelift omegas?
 
#5 ·
Can I wire my Subwoofer to my Astra's Standard H/U?

Hey,

I've just bought my self a twin-active 12inch FLI Sub woofer system. And I stupidly didn't check before, whether I could connect it to my factory fitted Astra head unit?

It is a CD500. Or would i have to buy a after market head unit and all the relevant cables?

Many thanks!
Mitch
 
#6 ·
Hey,

I've just bought my self a twin-active 12inch FLI Sub woofer system. And I stupidly didn't check before, whether I could connect it to my factory fitted Astra head unit?

It is a CD500. Or would i have to buy a after market head unit and all the relevant cables?

Many thanks!
Mitch
If the active sub has a 'High' input on the amp, you can run it from the stereo
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top