New Clarion Speaker

[richdave]

What you’d might want to try is placing 130uf electro cap across your main speakers to try and cut out the sub bass coming through.

Arent you just shorting out the low frequencies by doing this? What will this do to the amp?

Does the BA audio setup have a crossover network to "split" the low/mid/high frequencies for each set of speakers?

[olcoolone]

You are creating a very crude 6dB per octave at 100/120 Hz’s high pass filter for the main speakers.

If your amp doesn’t have to produce the frequency below 80 Hz’s, this leaves more power for the mid to high range be allowing more headroom in the amp.

This is only good in multi speaker systems like premium sound with sub.

I don’t think there is any high pass filters in the BA’s but I think there would be a low pass for the sub as you would get vocals coming through the sub.

All you do is connect the - side of the cap to the + side of the speaker and the + side of the cap to the + speaker wire……you leave the – speaker wire connected to the speaker.

SORRY there was a typo in the last message I posted the cap should have been a 330uf electrolytic.

If you want to go 1 step better make a 12DB per octave at 80/100 Hz’s high pass filter use the same cap the same way but put a 11mH choke/coil between the + and – of the speaker after the cap as well.

If anyone tries this in a Falcon please let me know what difference it made.

[richdave]

If you want to go 1 step better make a 12DB per octave at 80/100 Hz’s high pass filter use the same cap the same way but put a 11mH choke/coil between the + and – of the speaker after the cap as well.

You mean in parallel with the capacitor

On the high pass filter, usually there is an additional component which has a low inductance at high frequencies and a high inductance at low frequencies....An RC or preferrably an LC network. My original statement still stands, putting a capacitor across the speaker will only serve to act as a low inductance to the low frequencies effectively shorting that part of the audio spectrum out. What will this do to the amp?

[olcoolone]

An RC and LC network will not really alter the frequency as they either alter the impedance of the driver or the volume of the driver making it possible to balance a multi speaker system like a Tweeter that is overly bright to a mid range or a mid bass. (this is different to time alignment of tweeters and mid range speakers)

What I am talking about is high pass filters that let everything above the set low point through.

With the amp I mean the amp in the head unit in the dash not the sub amp in the boot.

By using a high pass filter on the head unit and main speakers you are altering the load characteristics of the amp and an amp will deliver better quality sound when it does not have to produce bass frequencies.

This is the same as if you had to run a sub of the main amp in the head unit sure you can do it but the other frequencies will suffer because the lower you go in frequency the more cone movement you need to produce a pressure wave so you can hear it ………..it’s all to do with wave lengths

In the late 80’s and early 90’s most of the leading brand car audio manufactures produced amps that were tri mode compatible for this reason.

Even today most amps on the market can’t run down to 20Hz’s due to power supply switching issues….. is you did an analysis of the amp you may find it will go to 20Hz’s but from 100 Hz’s down there will be a increase sub harmonics making it sound like it is producing a lot of base.

The only way to really fix this is to go to valve amps but then you have problems of supply voltage and currant load along with size.

Or you can use a A/B class amp for 100Hz’s to 20 Khz’s and still use it below 100Hz’s or use a class D amp for 100Hz’s and below (you can not use a class D amp above 100Hz’s due to power supply switching noise)

It’s the old story every thing is a compromise due to space and or price.

Sorry if I am wrong or I didn’t answer your question properly.

[olcoolone]

This link may help

http://www.the12volt.com/caraudio/cross12db.asp

[olcoolone]

This is better

http://www.the12volt.com/caraudio/cross.asp#hp

[Cam]

By using a high pass filter on the head unit and main speakers you are altering the load characteristics of the amp and an amp will deliver better quality sound when it does not have to produce bass frequencies.

Are you talking about putting a filter between the amp (the head unit) and its load??

If so how does this avoid the amp (in the head unit) from amplifying these frequencies??

Surely the AMP will amplify all frequencies within its capabilities that are contained in its input signal. The filter (the one we have installed) will then prevent some of these frequescies from reaching the load (speakers or additional amp).

If you wanted to prevent the amp in the head unit from having to amplify various frequencies you would need to posistion the filter on the input side of the amp not its output side. (which of course would not be a wise idea)

Am I missing your point perhaps - but I dont see how a filter on the output of an amplifier will effect what freequencies that amplifier is outputting?

[olcoolone]

HU

In the Falcon with premium sound there is two amps (one in the head unit in the dash 25 x 4 for the full range speakers and another in the boot for the sub 150 x 1) this is what I believe.

With the high pass filter on the speaker all you are doing is cropping the frequency going to the speakers:-

If you placed an amp meter on the power inputs on an amp and with music played into it from a CD player you may notice the amp is drawing 40 amps, now with the music set at the same volume disconnect the speakers and the amp meter will show nearly 0 amps….simple hey

If the amp can not see the frequency the speakers will accept (cross over), it will not produce power at the given frequency.

For example

You are driving you car along a flat road on cruise set at 100 Kph and a hill appears so you leave it on cruise and you climb the hill at 100 Kph…no big deal and then you travel down the other side of the hill still at 100 Kph on cruise…the only thing that appears to have happened was that the engine worked a bit harder going up the hill and a bit less going down the hill and the fuel economy went from a little higher to a little lower…no big deal

WHAT HAS THIS GOT TO DO WITH AUDIO

Take the flat road as your mid range signal (vocals and most instruments).

Take the up hill as bass (drums and doff doff).

Take the down hill as your highs (clarinet and men’s voices when castrated).

Take the speed as sound level.

Take the fuel as sound quality.

If the hill was maybe smaller or not there at your entire engine would not have to work harder and fuel economy would be lower, so if the bass is taken out your amp does not have to try a produce it and in return you your sound quality increases.

Have a look at page 80 of your owners manual under power limiting, this is mostly found on cheaper OEM car stereos to keep the customer happy and maybe warranty claims .You will never see it on good quality after market stuff…why, better amplification of the signal.

Next week I may talk about phantom centre speakers and AM stereo conversions…!

[Guest Mr Walker]

DavoXT,

I forgot to ask - did you start off with the std system or Prestige? Can't remember if you can get Prestige on std XT?

[DavoXT]

Prestige (standed with 6 disc stacker in dash) you can't get the premium which is a joke as a XT V8 cost more than a futura.