Active VS Passive crossover.

[kanwar]

Thanks for the explanation Kanwar.

Yes Plate amp is what I meant. Any well designed popular amp ? Audiophile if one must insist . Future of active speakers looks promising. Coaxials (Single point sound source) drivers with active crossover and well made amp seems the way to go.
Regards

Yet to see any in home audio.

 

[FCALA]

Hi guys,
First of all, I have to say that I have enjoyed reading this thread. Lots of great info!

My questions is this....

I have been looking at different crossover/amplification designs and so far I have found passive systems that use one amplifier and filters just before the driver and fully active systems that use an active crossover before separate amps.

What I am wondering is why no one uses passive filters feeding into separate amps that feed the drivers. Wouldn't this be the best of both worlds?

 

[matbhuvi]

Hi guys,
First of all, I have to say that I have enjoyed reading this thread. Lots of great info!

My questions is this....

I have been looking at different crossover/amplification designs and so far I have found passive systems that use one amplifier and filters just before the driver and fully active systems that use an active crossover before separate amps.

What I am wondering is why no one uses passive filters feeding into separate amps that feed the drivers. Wouldn't this be the best of both worlds?

There is a power loss when you go through passive crossover. Hence the first order passive crossover which has the minimal components is considered ideal. You need an amp before the passive crossover.

Passive crossovers are also impedance specific. You can not just take the passive crossover of speaker A and use it in speaker B. The impedance need to match. That adds another compatibility issue of adding amp after passive crossover.

 

[Danieljohn]

I say chaps, nothing better than not having crossovers at all in your speakers.

:clapping:I prefer Acoustical crossovers [Tannoy's compound horn 250/300 hz] :licklips:& Mechanical crossovers [Almost all whizzer cone Fullrange drivers]:yahoo: over Electricalhyeah:Crossovers

 

[Santy]

@Danieljohn

Please avoid quoting so many posts in a thread with no meaningful content other than smileys. I have removed all except one.

 

[GeorgeO]

I have just started the active journey with my new minidsp, looks like an interesting feature rich and powerful tool.

 

[nn_in]

B&O Tech Whats so great about active loudspeakers?

 

[Hari Iyer]

I'm no expert but am stating what has been told to me by a couple of experts who are involved in speaker & amplifier design with whom I've personally interacted.

Active crossovers are far more superior to passive crossovers, period.

I do not fully agree that active cross-overs are more superior to passive crossovers. Active or passive both depends upon how well it has been designed. Passive cross-overs take lot many effort to design, tweak and perfect and is lot time consuming. With active digital filters its more easy to play around for the design.

I personally believe that you should go for active if you have too many digital sources in the audio chain. If you are more of a vinyl / tube amp uses i will suggest passive cross-overs are the best bet for you. It does not make any sense using analogue source throughout your chain and use an active cross-over at the speaker end.

 

[GeorgeO]

If actives are far superior, then I wonder why many well known speaker brands have not switched over to them?

 

[keith_correa]

I personally believe that you should go for active if you have too many digital sources in the audio chain. If you are more of a vinyl / tube amp uses i will suggest passive cross-overs are the best bet for you. It does not make any sense using analogue source throughout your chain and use an active cross-over at the speaker end.

I don't understand this. What is the connection between an analog/digital source and active crossovers?

 

[keith_correa]

OT [not by so much though] but what are people's thoughts about PLLXO's?

 

[Fantastic]

PLLXO's?

Low level R and C are easier to get than suitable L . We find inductances in RF circuits as they are easier to fabricate in small sizes.
There have been circuits using RLC filters in phono preamps also but never became popular. It must be the difficulty in making suitably sized inductances.
However with just RC filtering this is a possible approach. But then you get stuck with maximum achievable Q of the circuit.
It isn't always possible to easily duplicate the characteristic of a passive speaker level crossover with a plain RC Passive Line Level XO.
But yes, in some cases it is possible to use it well , especially if we have very good drivers. Most DIY'ers will find it difficult to do this because it needs lots of building, testing and sufficient test equipment and "time".

Remember you can have a PLLXO partially in the amp and followed by a minimal passive power crossover in the speaker . But it would be a 'system' design as the PLLXO and the power amp are included in the "crossover" scheme !

 

[Fantastic]

If actives are far superior, then I wonder why many well known speaker brands have not switched over to them?

As we all know actives are available but belong to the 'higher end' of Hi-Fi which also automatically means very expensive.
Most speaker brands are geared to making and selling large numbers to achieve good profits and to keep costs down and hence making them affordable. This is not possible with an active system as they need to sell the electronics along with the speakers due to the embedded crossover in the design. So they will automatically be much more expensive.

But many hi-end hi-fi buyers want to use an amp of their choice. All power amps are not made identically. Gain and input impedances etc. vary all over the place. It's possible to overcome that but only by those in the know and that can't be too large !

Those who have spent lots of time mixing and matching will tell you that
combining different equipment isn't as simple as plugging them in as the end result might not achieve what one want's without modifications.

But with miniDSP and other linear crossover manufacturers, Pro's and DIY'ers can experiment with it themselves. It will end up being expensive AND labour is never counted in ( along with a whole string of other hidden expenses ).

This is a wide open field for DIY'ers to play around in !

 

[GeorgeO]

As we all know actives are available but belong to the 'higher end' of Hi-Fi which also automatically means very expensive.

Could you then tell us why a highly rated company like B & W makes active crossovers only for their Nautilus series but not for any others? Their 600,800, PM and CM? There must be some rationale behind it, right?

Why does Wilson Watt offer passive crossovers? Their speakers arent known for being inexpensive.

I'm not trying to start a flame war, all I'm saying is that making sweeping statements like the above can definitely be misleading.

 

[Danieljohn]

I feel Active Xovers are for speaker drivers which have a narrow frequency ranges like subwoofers, midranges[cone type for mid bass & dome type for mid hi's], tweeters, woofers[-6" for mid lows]

So building a passive 3/4/5 way crossover not going to be a easy task even if one does they mess up the sound Phase, Wher as with Active Xovers one can adjust Xover points precisiely as per

speaker drivers frequency responses [sweetspots] & have the advantange of using different amp types:

For High's - Single Ended Triode As they lack dynamic power & for their unique sound signature.

For Mid's - Same as above.

For Low's - Push Pull Triode to T-Class will do.

My setup is bypassed by all these complications by A 10"-15" [Far more linear Mechanically-Crossovered] Fullrange in a Big [Acoustically-Crossovered] TL & Simple seamlessly crossovering first order

network or a single cap between Fullrange & Super tweeter will also do reasonable job.

Aaron

 

[Danieljohn]

Aaron could you elaborate by an example or something : " Mechanically-Crossovered" driver / set up?

Yogi

All Whizzer Cone/Alloy Dome based Full Range Drivers have Mechanical Crossovers, Woofer/Whizzer/Alloy domes are Aligned & Positioned in such a way that they Reproduce Complete Audio

Spectrum without any peaks or dips in Frequency response, Thats the Reason Coral [Japan] gave "FLAT" name to their Full Range Drivers which i had for more than 2 decades in TL's.

I Do prefer Tweeters thou, but only the ones which Reach 100 Khz & above they will gave a Ceilingless Airy feel to Listeners but Xover must be First order only Slicing above 10 Khz Smoothly

To me 10"-15" Full Range drivers are the Ultimate if Installed in a TL or Compound Horn.



Aaron

 

[Hari Iyer]

I don't understand this. What is the connection between an analog/digital source and active crossovers?

No connection as such. If you strive to keep your signal path fully analog using a TT, Tubes then why use an digital cross-over at the final stage? Keep it passive.

 

[Fantastic]

Could you then tell us why a highly rated company like B & W makes active crossovers only for their Nautilus series but not for any others? Their 600,800, PM and CM? There must be some rationale behind it, right?

Why does Wilson Watt offer passive crossovers? Their speakers arent known for being inexpensive.

I'm not trying to start a flame war, all I'm saying is that making sweeping statements like the above can definitely be misleading.

Sorry,I'm not making any sweeping statements. Just my point of view. It isn't the gospel truth and I don't claim it to be so.

Every company has it's reasons for offering what they want. Making active systems is expensive. Each design is usually targeting a certain segment of buyers. So I can't say why their marketing team decided to do something. I'm just giving a logical viewpoint from a consumers point of view. There could be many others also ! Maybe someone really has the exact answers from the manufacturers board room too. We don't know , till they tell us.
We are just trying to reason out what we see. You can certainly disagree on that.
Have fun.
Cheers .

 

[GeorgeO]

Noted, and agree to disagree, cordially. As someone who has built multiple speaker systems using passives and has had one on one discussions with more than one US speaker designer on the subject of crossovers, I have had some insights into how crossovers are designed, which is why I too ex[pressed my point of view-basically, that there is no one perfect solution to crossover design be it passive or active. Nothing more, nothing less. To each his own.

Peace

 

[Santy]

TL related discussions can be continued here:
http://www.hifivision.com/diy/55381-tl-design-considerations.html