what is the concern(s) with having such a system? i've installed systems in other cars using the included passive crossovers, but this time i want to try something different with the TL. thanks!

 

Sorry for sounding stupid but what is the difference b/t an active and passive crossover?

 

the only concern is extra time and effor to set it up. the payoff is great though, especially if it has at least a 24db rolloff. also using this method means you are essentially biamping your components, so u will need at least a 4 channel amplifier just for ur component speakers.

the beauty of active(electronic device that electronically cuts off frequencies before the audio signal is amplified) vs passive(a circuitboard w/capacitors, resistors and inductors that filter out certain frequencies from an amplified audio signal) is that they are usually feature laden, where as a passive xover will usually only have tweeter cutoff adjustments, like mine, but nothing more. yeh, w/ active xover, you can set the xover frequency where ever u need it most, usually dictated by speaker placement. also, you are cutting up the frequencies before the signal is amplified. so the amplified music is usually gonna be better for sq(high end components can have passive xovers that rival active ones in sq though)

in a nutshell, active xover means versatility but time spent in getting it adjusted correctly.

passive xovers are pretty much connect and forget.

 

cool, pretty much what i thought! i'll post some pix when it's done. thanks!

 

- An active crossover filters the signal before it is amplified.

- A passive crossover filters after it's been amplified.

P.S. The only stupid question is the unasked one....


OOPS... I guess I should have read the rest of the thread before replying... Systek already answered that for you... oh well...

 

Very well explained by Systek, I might add...

As he mentioned, in HIGH END systems passive crossovers would actually sound better... assumming that you have everything designed and "selected" to be right on the money. That is probably easier to do in a home "listening room system" where you can measure and place the speakers where you want them... instead of living with odd placed speakers in a car. But in the end the more "PURE" the signal, the better it will sound. Any amplifier stage will induce its own design anomalies and artifacts. Just like any HU amplifier... NO TWO SOUND THE SAME. So the SQ would be very dependent upon the quality of the design and components involved. Of course this is true with passive crossovers or filters as well. Mylar caps are MUCH better sounding than electrolytic. But of course they are more costly... Again, it's how critical your ears are and how fat your wallet is. You could get poor, fair, good, or great sound from either method.

The ideal thing would be to have an active crossover installed to adjust things to where the ear finds the perfect sweet spot. Then measure all of the plots and values, and replace the active crossover with a HIGH QUALITY passive crossover having the exact same characteristics. That way you would have the perfect settings WITHOUT the amplifier noise and ringing, etc.

Of course that is going to the EXTREME. But I was just validating the point that Systek was trying to make about the pros and cons of each type of crossover.

In the future... whenever you read something that mentions "Active" or Passive" with respect to an electronic circuit.

An "active" circuit involves a stage that is active, meaning a device such as a transistor is used that takes voltage or a power supply to do its job... The inherent "gain" involved in an active device allows the circuit to accomplish the task without losing signal level, and/or can buffer input and output impedances by typical factors of several hundreds to one.

A "passive" circuit involves components that do NOT require any power supply to do their jobs, such as resistors, capacitors, and inductors. They will react to signals at different frequencies in different ways. However, since they are passive and simply react to the signal, there will be a resultant loss of gain through the components and impedance buffering is minimal. Depending upon the type of circuit... This may be preferable or unacceptable. It all depends upon what the circuit is designed to do....

SB

 

Some great info on crossovers:
http://www.crossovers.com/active_vs_passive.html

 

wow...talk about going to the extreme, ive never seen or heard anyone actually do that in car audio competition vehicles, but some of them bastids dont give out any of their secrets, jeje.

another problem that should be mentioned, or better explained is about the possible noise that SB mentioned. with added active components in any system, there is the possibility of introducing more noise into the audio signal. one of the most common problems that shows up is engine noise, better known as engine whine. this is usually due because of each component having its own ground contact which causes a ground loopback and picks up that noise(which is emi emitted by the alternator)

the cure for this is to try to have one grounding point for all your "active" components, such as the radio, eq, xover, and amplifiers. now, from personal experience, i have found that you can use 2 grounding points, as long as they are to bare metal and tight and secure, and not have any noise. i have done this in several different types of cars so its not an anomaly. One grounding point at the HU and another at the amp rack.

also, if you are upgrading your HU, go ahead and find a nice large bolt as the new grounding point. the factory ground is never quite as good and my friends and i have always found it to introduce noise when used.

enjoy...

 

southbound.. I don't get it you always write essays when you say something haha.. just a random observation.. but lots of info and always a good read btw thanks for this topic I was interested too just didn't post