Question about going active!

[Gill]

Can anybody explain about this process in layman terms,do's and don't's for going active.I read few articles but could understand much lol ,I know it means a seperate channel for each driver and the crossovers are placed before amplification takes place.But i want to know it in detail and the practical aspects of it.
Like, can i use two different amps to power the front midbass n tweeters!
If yes, then what about RCA? as the HU has just one RCA for the fronts!These sort of question are on my mind!
If someone can explain indetail,it would be helpfull or post a link from where i can gain some insight!!

Cheers!

[gunbir]

Originally Posted by Gill

Can anybody explain about this process in layman terms,do's and don't's for going active.I read few articles but could understand much lol ,I know it means a seperate channel for each driver and the crossovers are placed before amplification takes place.But i want to know it in detail and the practical aspects of it.
Like, can i use two different amps to power the front midbass n tweeters!
If yes, then what about RCA? as the HU has just one RCA for the fronts!These sort of question are on my mind!
If someone can explain indetail,it would be helpfull or post a link from where i can gain some insight!!

Gill saab,

The concept of active means you have no passive (read: physical) crossovers. It is all done in the digital domain (ideally, but one can also use amp's analogue crossovers).

Let me give you an example:

The Pioneer P80, Alpine 9887 can do 3way active. That means they will do Highs + Mids + Subwoofer (instead of Front + Rear + Sub) if used in active mode. So you need 6 channels of amplification (or 5 if you use a mono channel for the sub) and you will only run a pair of tweeters, midbass and sub(s).

The crossover points are set from the HU. In this case your tweeters will have a HPF. The midbass will have a bandpass (that means HPF and LPF). And the sub will have only LPF.

So lets say you set your Tweeter's HPF @ 3KHz, your Midbass's LPF @ 3KHz and HPF @ 80Hz, your Sub's LPF @ 80Hz. That means your tweets play everything above 3KHz. Your Mids play everything between 3KHz and 80Hz and your sub plays everything below 80Hz. I have left out subsonic for the sake of simplicity.

advantages:
- Set tweeter level as you please
- Time Align midbass to suit your installation

disadvantages:
- no rear fill possible
- need more amp channels
- if not careful, can damage drivers (usually tweeters) by choosing wrong crossover settings and levels.

Hope this makes sense... If not, call me

[Gill]

Originally Posted by gunbir

advantages:
- Set tweeter level as you please
- Time Align midbass to suit your installation

disadvantages:
- no rear fill possible
- need more amp channels
- if not careful, can damage drivers (usually tweeters) by choosing wrong crossover settings and levels.

Thanks Gunbir bai ji!
NO REAR FILL is a big disadvantage!It kills the dream right there , was thinking of getting six channel of amplification for tweets,mid fronts and rears.
Is there no way out to have rear along with active setup on 9887!Even fully adjustable crossover on amp won't help?
are these the only advantages that i will gain by going active?

Cheers!

[DerAlte]

Gunbir-ji, any other simpler method of doing 3-way active in front AND having rear fill? Like snake mar-jaing and stick also not tooting?

[Bass&Trouble]

Originally Posted by DerAlte

Gunbir-ji, any other simpler method of doing 3-way active in front AND having rear fill? Like snake mar-jaing and stick also not tooting?

Using an outboard active crossover for just the fronts, running the rear off the full range output off the rear pre-out of the head unit.

Or using an amplifier that allows you full active crossover controls on-board i.e. LP/ HP/ BP.

[DerAlte]

Originally Posted by Bass&Trouble

Using an outboard active crossover for just the fronts, running the rear off the full range output off the rear pre-out of the head unit.

Or using an amplifier that allows you full active crossover controls on-board i.e. LP/ HP/ BP.

What is the difference between an outboard active crossover (at that power level, say 50W in the mid-bass/mid range) and an amplifier with full active crossover controls on board?

By active crossover you mean the segregation is at the low signal level - or am I getting it wrong? Any examples of such amps?

[Bass&Trouble]

Originally Posted by DerAlte

What is the difference between an outboard active crossover (at that power level, say 50W in the mid-bass/mid range) and an amplifier with full active crossover controls on board?

Where did power come into the picture, sir?

Gunbir was citing the Alpine head unit example where the filtering is performed in the head unit and insteadd of front, rear and sub out you get low, mid, high out. Not all head units do this. So for a regular head unit just doing F + R + Sub, you take the front pre-out, feed it to a seperate active crossover that gives you low/ mid/ high pre-outs. Then use 6 channels of amplification just for the front, assuming you are using 3-way fronts.

By amplifier with active crossover capability, I mean an amp that accepts the full range signal from the headd unit's front output as above and does the same HP/ LP/ BP without the need for the additional active crossover.

Originally Posted by DerAlte

By active crossover you mean the segregation is at the low signal level - or am I getting it wrong? Any examples of such amps?

Yes, in active crossover segregation is always at the low level, right?

Almost all amps have active crossover on board, the HPF/ LPF settings, some with crossover frequency adjustment. This is also an active crossover. There are others like the Steg K series which allow you to do HP/ LP/ BP for a very wide variety of frequencies unlike the limited band in the regular amps.

Something like this:

[thefreak]

Boy! talk about explaining the technicalities to a layman

[DerAlte]

Originally Posted by Bass&Trouble

Where did power come into the picture, sir?
.... Then use 6 channels of amplification just for the front, assuming you are using 3-way fronts.

You answered your question! Your earlier expression was a bit misleading - the amplification was implicit. I realize now that you were always talking of the low-signal part.

Originally Posted by Bass&Trouble

Yes, in active crossover segregation is always at the low level, right?

Sure, but sometimes it is better to be on the same plane: senior moment, as Navin puts it

Thanks, the diagram is very illuminating - will help anyone who is planning active without P80 or 9887.

[Gill]

Can you plz quote few amps that have active xovers!Outboard active x-overs like H701???

[moralfibre]

Originally Posted by Gill

Can you plz quote few amps that have active xovers!Outboard active x-overs like H701???

I for sure know Steg amps do have onboard crossovers with option of choosing modules for choosing cut off frequencies.

Steg crossover modules. (1.5 Lakhs Budget for ICE in Cr-V EDIT: Now installed Pics on page 4)

[low_bass_makker]

Originally Posted by Gill

Can you plz quote few amps that have active xovers!Outboard active x-overs like H701???

Ya H701 can do that. With 9887 and H701 you can go for a 4-way active setup wth high, mids , midbass, lows.

You can use PXA to make it for the 3-way active and 1 rear channel also.

But why spend on PXA if every thing can be done by a Steg amp.

[clipto333]

gill,

why really are you stuck with the rear fills? only if sit at the back, then it is useful. and it wont have the sq of a component speaker for sure.

install another HU for your rear fills lol.

i think my pio amp can do active as it has hp, bp, lp + i can switch the xo to high or low frequency bands.

[Gill]

I am just looking for going two-way active in front(High-midbass,no three ways).
Now the question is can i go active with a fully adujstable 4 channel amp for fronts,and a seperate two channel amp for the rear.Crossovers on HU set to flat and crossovers on the amp do the needfull?

Regarding rear fills(Co-ax shall soon be replaced by something better),i need to have a balance sound in the car,though when i am driving alone i can fade the rears!

[clipto333]

Originally Posted by Gill

I am just looking for going two-way active in front(High-midbass,no three ways).
Now the question is can i go active with a fully adujstable 4 channel amp for fronts,and a seperate two channel amp for the rear.Crossovers on HU set to flat and crossovers on the amp do the needfull?

Regarding rear fills(Co-ax shall soon be replaced by something better),i need to have a balance sound in the car,though when i am driving alone i can fade the rears!

i think its doable. but you wont have the xo controls at your finger tips but you don't adjust tthe xos so i think it will be all right.

everyone has different tastes and i can understand the need for rear fills. my wife will never drive our car if i remove thos infinity's. some how, i will have to fing a way to power them when i go 3-way active. i would have preferred a 4way active xo but i would be spending around 50k for a HU which can do that. some day i will do that for sure. an hx-d2.

for now im going for the 9887. but im still thinking of the clarion which has that toch panel thingy.

i think gunman has installed that HU. would love to have his opinion on the 9887 and the clarion. both can do TA and have 3 way active xos.

honestly tell me, do you listen to the rears while driving or its for the passengers seated there? or you sit at the back?