Active vs Passive Setup

[Unclesoong]

WOW!! News travels fast!

[Sarong1]

Hi Uncle soong, what about going "semi-active" then for car audio? I have heard this terminology in home audio, still very vague in terms of my understanding on their concept. It still retains a passive crossover for the 2-way but active for the mids or something like that. It also involves bi-amp. Is this ever tried in car audio before???

[Unclesoong]

Yes, heard some set ups doing semi-active.

Semi active means using the active crossover to bandpass the mids and the passives high passing the tweeters.

But bear in mind that the crossover points at the passives is not tunable and it's fixed.

That means as compared to a passive system, you get an extra option to low pass the mids, that's all.

I personally would like to either go full active or just simply stay with a passive system.

[Icboc_lee]

long time didnt chat in the forums.Dont mind to add something.

when talk about the passive.Normally we will re build the crossover. Bcos most of the crossover cannot support the enviroment inside the car. What i meant the dB for the car and the positioning of the tweeter+midbass. So the EQing will be different.

What my friend did was rebuild their crossover to enhance the system. Bcos the crossover point and slop may change when inside the different car/positioning of tweeter.

 

Personally, i like Active. of cos must using the HU are able to support. i personally will choose F1. Because active you will fully control the system in different enviroment. EQing and crossover also can set according to it. EQing is very important to the car

[Mrlee]

Where is the best shop to install these?

[Lionheart7004]

UNTRUE!!

As long as you are not sending clipped signals to your speakers, you will not be having problems with yur speakers.

If you run active, just be careful on your HPF on the tweeters, setting them above 3khz usually should be OK.

Putting those resister caps on the tweeters will compromise the details and resolution of your high frequencies and a big no no!!

Active systems do not mean better sounding as compared to passive systems.

Just that active systems allow you more flexibility in tuning to improve on your staging and imaging.

 

Unclesoong,

 

Can you bother to eloborate on difficulties to improve staging and imaging via passive crossover?

[Mdvic]

Bor,

 

Tks for the very "Chiem" explaination on the Active and Passive setup..

 

My setup is like that, if you where me will you go for passive or Active?

My final decision is !!!!!!!...

 

1.Pioneer DEHP - 9650MP Cd Turner / Head Unit

 

2.Soundstream TRC.6 - Soundstream Component Speakers / Front Speakers

2ch amp 250w x2 @4 ohms Or bridge RMS power :500w x 1 @ 2 Ohms

 

3.Lanzer Heritage HR6.1-Component Speakers / Back Speakers

2ch amp 250w x2 @4 ohms Or bridge RMS power :500w x 1 @ 2 Ohms

 

4. Soundstream XS-12 - 12" 4 Ohm DVC Subwoofer 300w RMS

JBL BP-600.1 - Subwoofer Mono Amp

 

5.Boss Audio CAP20BK- 1.2 Farad Capacitor w/ Digital Voltage Display

-----------------------------------------------------------------------------------

Edited June 6, 2006 by Mdvic

[Neotan]

Hi all,

 

I have difffering views on the ability of DEH-9800 BT to support an active set up

(http://www.pioneer.eu/eur/product_detail.jsp?product_id=12583&taxonomy_id=25-121)

 

According to the installer, the tuning options are limited only to front , rear and sw - not the mids - therefore I need only a 2-chan amp. An bro on forum claims that it DOEs support active.

 

I don't not intend to have a SW (due to space constraints) and have purchased the Oz matrix 180cs only.

 

Please advise...

 

 

Regards,

 

Neo Tan

[Neotan]

It's ok... It's confirmed that the HU does not support active setup

[Neotan]

I find the tutorials found here to be pretty useful...

 

 

http://mobile.jlaudio.com/products_amps_pages.php?page_id=30

[Jwho]

Hi,

I am also a newbie into ICE. I have the following setup in my car but havent install it and would like some advice on what is the optimum setup for my ride (mazda 3 sedan).

 

- Stock mazda 3 HU

- Infinity component speakers with tweeters and crossovers.

- Infinity 2 way speakers

- Rodek 4 channel Amp

- Cadence Pre-amp

- JBL CS200 monobloc amp

- Sony 12" Xplod Subwoffer enclosed in Customized wooden box.

- Stinger capacitor to power up the JBL monobloc

 

I am thinking of taking out the subwoofer from the wooden box and fix it on my spare wheel area with acrylic top to save some booth space. any comments on the pros and cons?

 

appreciate any advice..

 

have a good day,

[Bobneo]

Building your own X-over is quite risky as I understand that good speaker already come with complicatred X-over network that is used to tune to the electro mech properties of the speaker to achieve optimum performance. It is not just a matter of getting the right X-over freq but the speaker need to mantain a flat elecrtical AC impedance over a wide range of freq specturm or bandwidth. The reactance or AC impedance will vary with frequency. Looking at the no. of component that are used in some expensive or good speaker X-over network will tell you that it is not an easy job to replace it.

 

Another point that need to take note is removing the tweeter from the X-over network without a series capacitor for full active could be quite risky as DC from the amp may burn the tweeter coil during high surge current at the point of turning on the system, so would advise you to put a series cap for the tweeter for full active as the voice coil wire in tweeter is very fine. Cap will block the DC current from entering the voice coil wire. For the mid/low woofer, it is ok to do without series cap as the voice coil wire are thick enough to handle a few mili second of surge current.

 

Choosing the right kind of series cap for the tweeter is also not easy as different cap value will have also affect the bandwidth as cap is a high pass in nature so it will limit the low pass freq. Rule of thumb is that bigger capacitance will allow lower high pass frequency point. Also the material that is used to make the dielectric of the cap will also impact the sound quality, the best are those using Teflon as Teflon is very stable at high frequeny, cheaper type will be the polyproplene or polyester or polyxxxx type. Use non-polarized cap and do not use polar Elec cap.

 

Some pple call it black magic use by installer but I say it is basic electrical engineering know-how coupled with trial and error to find the right match to your system as your ear is the final judge.

[Kwchan]

wah...didn't know run active must put capacitor, i tot just turn on the HPF on the amp will be good enough

 

so what kind/brand/spec of cap do u recommend and where shall i put it?

 

can find in SLT?

 

thanks

[Headshok]

haha..

 

tink u got it mixed up..

 

in a passive cross over, one of the important components is a capacitor(u open up ur passive Xover and see, those tube like things are capacitors). don get it mixed up with the the caps that u put to power systems.. haha.

 

aniway, for active setups, the HPF on the amp is NEVER good enough. if u wanna run like that, use the passive Xover that comes with ur components will result in better sound

[Kwchan]

i am running active, and my tweet dont come with any X-over

 

i know he is referring to different type of cap, from the equation here:

 

http://www.carsound.com/columns/clark/clrk0012.shtml

 

i should use a 40uF cap, let me see if i can rip off two from my old hardware

Edited March 24, 2007 by Kwchan

[Hyun]

>aniway, for active setups, the HPF on the amp is NEVER good enough. if u wanna run like that, use the passive Xover that comes with ur components will result in better sound

 

addchilli ah, ah shiok, most amps (donno about crap ones lah) active xover is fine, and i'd say even better than using the passive cross. i've met some who say they're some form of purists, believing that passive sounds better. that's probably an illusion resulting from a different sound from the passive cross - difference in levels, freq response, phasing etc.

 

the reason an active cross beats a passive is mainly cos both are (probably) using pretty reasonable-quality components but the passive adds in-line impedance to the amp load, wasting power effectively. and if the component quality isn't good, the passive cross can add further distortion of sound with roll-offs etc. it's cheaper to make good-component active cross than passive cross due to the smaller components involved so most amps should have decent active cross components compared to the equivalent-grade passive cross.

 

for more budget passive speaker sets, u also frequently see passive crosses like -6db/oct LPF for midbass, less frequently even -6db/oct HPF for tweeter (e.g. in coaxials). the more common slopes are -12db/oct. many of these slopes may be less-than-ideal for in-car tuning, and u might do better with an active cross with a more appropriate slope.

 

the good thing about passive cross is that it's phasing is probably taken into account. many people tuning active systems might end up leaving their phasing wrong at the cross without knowing it.

[Bobneo]

Yes, you can buy the cap from shops in the basement in Sim Lim tower or Martin electronics in Burlinton Square which is opposite Sim Lim square.

[Newkid]

Hi,

 

Just to check with everyone..

 

If i am using only passive setup...with a pair of tweeter and mid-range connect to 1 channel of the amp. On my amp side, there is a switch to set to HP, LP or off. Should i set to HP or set it to off. Please advise. Thanks

do you have a cross-over to split the freq between the tweeter and mid bass? if yes, then set the switch to "all"