electronic crossover

[Andrewjvt]

Has anyone got experience with an electronic cross over?

Has anyone removed the passive crossover from a speaker and then created an active speaker?

Can an electronic cross over divide the hf, mrf and lrf using one stereo amp or are multipul amps required?

I was up reading about this on the net till 2 this morning.

I was thinking i can make my own active speaker.

All advice and help much appreciated.

 

[davedotco]

Has anyone got experience with an electronic cross over?

Has anyone removed the passive crossover from a speaker and then created an active speaker?

Can an electronic cross over divide the hf, mrf and lrf using one stereo amp or are multipul amps required?

I was up reading about this on the net till 2 this morning.

I was thinking i can make my own active speaker.

All advice and help much appreciated.

Yes.

Yes, sort of.

An electronic crossover will divide the incoming signal into frequency limited 'bands', each band will require it's own power amplifier. If it is a three way system (bass, mid, treble) then you will need three channels of amplification per speaker.

If you are thinking of converting existing passive speakers for active use, then you need to be aware that in passive systems the crossover often does more than simply 'crossover' the drive units, it has to adjust for different sensitivities and often 'shapes' the signal fed to the drivers in order to modify the raw response of the drive units.

 

[Andrewjvt]

The other thing to take into account is the power requiments of each driver, bass drivers need more power than the high frequency drivers, so in actives you may see 200w amp for bass and 50w for tweeters. Actives should have amps tailor made for each driver, because they know the power and the impediance of each. So its not as straight forward as you may think.

Yes well aware of that one
And already had amps in mind but may just stick with the passive build as the cost per sound improvement may not justify but im looking deeper into it. Thanks for the reply

 

[Andrewjvt]

Has anyone got experience with an electronic cross over?

Has anyone removed the passive crossover from a speaker and then created an active speaker?

Can an electronic cross over divide the hf, mrf and lrf using one stereo amp or are multipul amps required?

I was up reading about this on the net till 2 this morning.

I was thinking i can make my own active speaker.

All advice and help much appreciated.

Yes.

Yes, sort of.

An electronic crossover will divide the incoming signal into frequency limited 'bands', each band will require it's own power amplifier. If it is a three way system (bass, mid, treble) then you will need three channels of amplification per speaker.

If you are thinking of converting existing passive speakers for active use, then you need to be aware that in passive systems the crossover often does more than simply 'crossover' the drive units, it has to adjust for different sensitivities and often 'shapes' the signal fed to the drivers in order to modify the raw response of the drive units.

I had in mind
Wilmslow audio k100

Use an abrahamsen power amp for tweeter at 70w. My hegel pushes 250w for bass then would need something between or about 150w for mids.

Thats why i asked if i could use my amp for mid and bass then seperate amp for highs until possible other power amp for bass
Possibly hypex?

 

[BigH]

The other thing to take into account is the power requiments of each driver, bass drivers need more power than the high frequency drivers, so in actives you may see 200w amp for bass and 50w for tweeters. Actives should have amps tailor made for each driver, because they know the power and the impediance of each.

 

[Benedict_Arnold]

If you are going to all ths trouble, why not just buy some off the shelf power amps and tri-amp your speakers with the same amps feeding HF, MF and LF?

Most "up market" bi / tri amp-able speakers don't actually have crossovers as such. The little brass jumpers between the speaker terminals on the backs of such units merely convey the same full spectrum signals to each cone and let the cones sort it out for themselves.

 

[davedotco]

If you are going to all ths trouble, why not just buy some off the shelf power amps and tri-amp your speakers with the same amps feeding HF, MF and LF?

Most "up market" bi / tri amp-able speakers don't actually have crossovers as such. The little brass jumpers between the speaker terminals on the backs of such units merely convey the same full spectrum signals to each cone and let the cones sort it out for themselves.

Complete and total nonsense!

Of course they have crossovers, just separate ones for each frequency band.

 

[davedotco]

Has anyone got experience with an electronic cross over?

Has anyone removed the passive crossover from a speaker and then created an active speaker?

Can an electronic cross over divide the hf, mrf and lrf using one stereo amp or are multipul amps required?

I was up reading about this on the net till 2 this morning.

I was thinking i can make my own active speaker.

All advice and help much appreciated.

Yes.

Yes, sort of.

An electronic crossover will divide the incoming signal into frequency limited 'bands', each band will require it's own power amplifier. If it is a three way system (bass, mid, treble) then you will need three channels of amplification per speaker.

If you are thinking of converting existing passive speakers for active use, then you need to be aware that in passive systems the crossover often does more than simply 'crossover' the drive units, it has to adjust for different sensitivities and often 'shapes' the signal fed to the drivers in order to modify the raw response of the drive units.

I had in mind Wilmslow audio k100

Use an abrahamsen power amp for tweeter at 70w. My hegel pushes 250w for bass then would need something between or about 150w for mids.

Thats why i asked if i could use my amp for mid and bass then seperate amp for highs until possible other power amp for bass Possibly hypex?

Good luck with that.

In theory you could split the supplies crossover so that you disgard the part that crosses over from the bass to the mid, just use the part that crosses over from the mid to the highs.

Use an electronic crossover between the bass and the mids.

However, you will need to match the sensitivity and the gain of the two amplifiers which in this case will be quite dissimilar. Probably other issues too.

 

[Vladimir]

Probably other issues too.

Time alignment, phase issues, drivers ringing into breakup mode...

It's an expensive kit to start learning things by ear.

 

[Andrewjvt]

I may one day try to make an active 2 way but ill stick to the passive for now.
Thanks guys if its gonna be a pain ill forget it but was worth a shot.
Im getting the k100 btw and illl stick on a new thread with my demo reactions.
This will be my kit for until it breaks or i become rich.
any new upgrades will be active.

 

[expat_mike]

I may one day try to make an active 2 way but ill stick to the passive for now. Thanks guys if its gonna be a pain ill forget it but was worth a shot. Im getting the k100 btw and illl stick on a new thread with my demo reactions. This will be my kit for until it breaks or i become rich. any new upgrades will be active.

You may find this interesting http://www.linkwitzlab.com/sb80-3wy.htm

I planned to build this system, and bought the drivers, and some of the electronics, but never got any further.

It seemed such an unusual hifi design in those days, but of course 35 years later, it would be considered 'normal'.

 

[steve_1979]

I was thinking i can make my own active speaker.

MiniPSP make amp plates with a built in active crosovers that have everything you'll need to convert a passive speaker into an active speaker:

Clicky

 

[spiny norman]

Here's a thread with lots of info and links to manufactures who make active crossovers, amp plates and other resorces that might be helpful.

Clicky

I really miss Keith Harris and Orville the Duck.

 

[Andrewjvt]

I may one day try to make an active 2 way but ill stick to the passive for now. Thanks guys if its gonna be a pain ill forget it but was worth a shot. Im getting the k100 btw and illl stick on a new thread with my demo reactions. This will be my kit for until it breaks or i become rich. any new upgrades will be active.

You may find this interesting http://www.linkwitzlab.com/sb80-3wy.htm

I planned to build this system, and bought the drivers, and some of the electronics, but never got any further.

It seemed such an unusual hifi design in those days, but of course 35 years later, it would be considered 'normal'.

A good read thanks

 

[Andrewjvt]

I was thinking i can make my own active speaker.

MiniPSP make amp plates with a built in active crosovers that have everything you'll need to convert a passive speaker into an active speaker:

Clicky

 

Im gonna read about that but think im going to build the passive now lol

Looks very interesting btw

 

[lindsayt]

All you need is an adjustable active crossover. Plus a small stack of amps. Each of which can be bought for under £200.

My adjustable active crossovers have both had volume controls for each frequency band. This allows you to compensate for different driver efficiency and amplifier gain.

In any active system I'd still want a capacitor in circuit for the midrange and treble drivers as protection in case of amp failure. Unless, of course, the drivers were cheap and easily available.

 

[Benedict_Arnold]

If you are going to all ths trouble, why not just buy some off the shelf power amps and tri-amp your speakers with the same amps feeding HF, MF and LF?

Most "up market" bi / tri amp-able speakers don't actually have crossovers as such. The little brass jumpers between the speaker terminals on the backs of such units merely convey the same full spectrum signals to each cone and let the cones sort it out for themselves.

Complete and total nonsense!

Of course they have crossovers, just separate ones for each frequency band.

Those aren't crossovers, then, are they? If they are there at all, they're high and low pass filters there to prevent the excesses only. If there are geniune crossovers, why bother with putting bi-wire bi-amp terminals at all? And why does the sound improve when you do bi-amp or replace the jumpers with speaker cable? Like I said, most high quality bi-wireable / bi-ampable speakers let the drivers sort it out for themselves.

 

[Benedict_Arnold]

The circuit diagram below is for a Polk Monitor 70 bi-wireable speaker, pinched off the internerd. Some detail is missing, but you'll get the gist if you know what you're looking at (and if I can get the WHF forum to post up the picture).

The main point is that the LF and HF circuits are completely separate. You'd only get HF and LF if you bridge the terminals on the back of the speaker.

The circuit on the upper speaker (tweeter) uses a coil in parallel as a LF by-pass and the capacitors as LF-blockers.

The middle speakers see the full range of sound.

The lower speakers use a capacitor in parallel as a by-pass for higher frequencies only.

http://cd8ba0b44a15c10065fd-24461f391e20b7336331d5789078af53.r23.cf1.rackcdn.com/polkaudio.vanillaforums.com/attachments/1/9/8/6/1/3/73785.png

 

[andyjm]

Those aren't crossovers, then, are they? If they are there at all, they're high and low pass filters there to prevent the excesses only. If there are geniune crossovers, why bother with putting bi-wire bi-amp terminals at all? And why does the sound improve when you do bi-amp or replace the jumpers with speaker cable? Like I said, most high quality bi-wireable / bi-ampable speakers let the drivers sort it out for themselves.

Benedict, I don't know what you think is in a crossover, if not a low pass filter in front of the woofer and high pass filter in front of the tweeter.

Bi wire terminals are there for marketing reasons, replacing the link with cable is going to make no difference.

I am afraid I have no idea what 'let the drivers sort it out for themselves' means. The Polk circuit you linked to shows a classic LCR crossover design.

 

[Benedict_Arnold]

A crossover connects a single pair of inputs to both woofers and tweeters. Clearly in the circuit diagram I posted you clearly see woofers and tweeters are NOT connected to the same input terminals and without jumpers all you would get from one pair of speaker wires is all bass / midrange or all treble. Might be semantics but the filters aren't crossovers.
And from hands on practical experience from a pair of ProAc Studio 140s, a pair of Mordaunt Short Mezzo 6s and the wonderful (ahem) Klipsch Reference 42s I'm currently saddled with, unless the clips are in place, one pair of speaker wires gives all treble or all bass.
The defence rests, m'lud.

 

[andyjm]

A crossover connects a single pair of inputs to both woofers and tweeters. Clearly in the circuit diagram I posted you clearly see woofers and tweeters are NOT connected to the same input terminals and without jumpers all you would get from one pair of speaker wires is all bass / midrange or all treble. Might be semantics but the filters aren't crossovers. And from hands on practical experience from a pair of ProAc Studio 140s, a pair of Mordaunt Short Mezzo 6s and the wonderful (ahem) Klipsch Reference 42s I'm currently saddled with, unless the clips are in place, one pair of speaker wires gives all treble or all bass. The defence rests, m'lud.

Benedict, I am afraid I am struggling to see your point. With the jumpers in place, the Polk circuit you linked to is a normal crossover design, with the jumpers removed it has been separated into its two constituent parts, a low pass filter and a high pass filter.

Why anyone should want to separate the two parts of the circuit has never been clear to me.

 

[lindsayt]

A crossover connects a single pair of inputs to both woofers and tweeters. Clearly in the circuit diagram I posted you clearly see woofers and tweeters are NOT connected to the same input terminals and without jumpers all you would get from one pair of speaker wires is all bass / midrange or all treble. Might be semantics but the filters aren't crossovers. And from hands on practical experience from a pair of ProAc Studio 140s, a pair of Mordaunt Short Mezzo 6s and the wonderful (ahem) Klipsch Reference 42s I'm currently saddled with, unless the clips are in place, one pair of speaker wires gives all treble or all bass. The defence rests, m'lud.

That Polk diagram does indeed show a passive speaker crossover. The "single pair of inputs" in this example are the output terminals of the amplifier.

The only difference between bi-wired and non bi-wired systems is the speaker cable part of the circuit between the amplifier terminals and the speaker terminals.

You still have shared wire in the curcuit with bi-wired systems. This being the wire inside the amplifier from the output devices to the amplifier speaker terminals.

Think about it. Picture the whole circuit from amplifier transistors / output transformer to speaker drivers.

For non-biwirable speakers, you could achieve the same disconnection effect as with your Klipsch, MS, Proac by opening the speaker and disconnecting the wires at the input to either the treble or the mid-bass part of the passive crossover.

The only difference between a bi-wirable and non biwrable speakers is the layout of the internal cabling inside the speaker (from terminals to crossover inputs), or the sharing of the speaker terminals.

For speakers that are designed for easy conversion to active crossover mode, there may well be terminals that are connected directly to the drivers without passing through a crossover.

All that bi-wirable speakers allow you to do, is to optimise the speaker cable for treble or mid-bass duties. Some people feel that that is of some importance to the sound quality. Others feel that it is not particularly important in the grand scale of things in a hi-fi system.

 

[Andrewjvt]

All you need is an adjustable active crossover. Plus a small stack of amps. Each of which can be bought for under £200.

My adjustable active crossovers have both had volume controls for each frequency band. This allows you to compensate for different driver efficiency and amplifier gain.

In any active system I'd still want a capacitor in circuit for the midrange and treble drivers as protection in case of amp failure. Unless, of course, the drivers were cheap and easily available.

Thus was kind of what i was thinking...

In my situation how would i fit a capacitor to protect the midrange and hf drivers?

Btw the drivers are not cheap
The mid range is £750 a pair
the tweeter is cheap at about £50-£70 but 8 was thinking of going up to the high class range anyway..

Also as quite expensive to learn on but if can be done. The results could be very good considering the already very good passive performance.

Maybe i could in the future build a simple 2 way active to learn on before going all out to replicate a scm100 active

 

[davedotco]

A crossover connects a single pair of inputs to both woofers and tweeters. Clearly in the circuit diagram I posted you clearly see woofers and tweeters are NOT connected to the same input terminals and without jumpers all you would get from one pair of speaker wires is all bass / midrange or all treble. Might be semantics but the filters aren't crossovers. And from hands on practical experience from a pair of ProAc Studio 140s, a pair of Mordaunt Short Mezzo 6s and the wonderful (ahem) Klipsch Reference 42s I'm currently saddled with, unless the clips are in place, one pair of speaker wires gives all treble or all bass. The defence rests, m'lud.

Benedict, I am afraid I am struggling to see your point. With the jumpers in place, the Polk circuit you linked to is a normal crossover design, with the jumpers removed it has been separated into its two constituent parts, a low pass filter and a high pass filter.

Why anyone should want to separate the two parts of the circuit has never been clear to me.

I'm afraid that B_A does not undestand the basics. Ie a passive crossover being a device that splits the incoming signal into bandwidth limited sections to drive each drive unit, hence the silly suggestion that the individual speakers somehow sort it all out themselves.

Each 'filter' is a separate circuit that only connects to the other filters at the terminals of the speaker, if single wired or the amplifier if bi-wired.

This is absolutely basic stuff, if you don't understand it, best not to comment on it.

 

[Andrewjvt]

A crossover connects a single pair of inputs to both woofers and tweeters. Clearly in the circuit diagram I posted you clearly see woofers and tweeters are NOT connected to the same input terminals and without jumpers all you would get from one pair of speaker wires is all bass / midrange or all treble. Might be semantics but the filters aren't crossovers. And from hands on practical experience from a pair of ProAc Studio 140s, a pair of Mordaunt Short Mezzo 6s and the wonderful (ahem) Klipsch Reference 42s I'm currently saddled with, unless the clips are in place, one pair of speaker wires gives all treble or all bass. The defence rests, m'lud.

Benedict, I am afraid I am struggling to see your point.  With the jumpers in place, the Polk circuit you linked to is a normal crossover design, with the jumpers removed it has been separated into its two constituent parts, a low pass filter and a high pass filter.  

Why anyone should want to separate the two parts of the circuit has never been clear to me.

I'm afraid that B_A does not undestand the basics. Ie a passive crossover being a device that splits the incoming signal into bandwidth limited sections to drive each drive unit, hence the silly suggestion that the individual speakers somehow sort it all out themselves.

Each 'filter' is a separate circuit that only connects to the other filters at the terminals of the speaker, if single wired or the amplifier if bi-wired.

This is absolutely basic stuff, if you don't understand it, best not to comment on it.

Why vertical bi amping sometimes does not yeld much improvement perhaps