electronic crossover

[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.

Why vertical bi amping sometimes does not yeld much improvement perhaps

Passive bi-amping, whether vertical or horizontal has minimal if any effect, other than on the wallet.

The expectation that 'doubling' the amplifier 'power' (at substantial cost) will improve the sound quality will of course convince many that bi-amping is better.

I can think of no technical reason why bi-amping is better and several as to why it is worse. I have never heard any benefits and to my knowledge, there are no convincing tests that show any.

 

[abacus]

Bi-amping does give a small improvement over straight single wiring, as the output power is spread over more output transistors; however it is in not worth spending extra money on additional amps unless you have a spare amplifier lying around, or you have spare outputs available on your AV Receiver that can do the same.

Bill

 

[abacus]

For creating an active speaker with external amps, get one of these https://www.soundtech.co.uk/music-retail/dbx/driverack/driverack-pa2 then add this https://www.soundtech.co.uk/music-retail/dbx/driverack/rta-m and add as many as these http://www.music-group.com/Categories/Behringer/Power-Amplifiers/Studio-Monitor-Amplifiers/A500/p/P0217 as you need.

Sorry the links aren't active (You will need to copy & paste) as the spam filter blocks the post with them in. (It seems the spam filter only allows spam through, not genuine posts)

Hope this helps

Bill

 

[jiggyjoe]

If your interested in building your own speakers i suggest you have a look here:http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm

Lots of designs and he goes into the pro's and con's of active and passive speakers.

 

[davedotco]

Bi-amping does give a small improvement over straight single wiring, as the output power is spread over more output transistors; however it is in not worth spending extra money on additional amps unless you have a spare amplifier lying around, or you have spare outputs available on your AV Receiver that can do the same.

Bill

about this Bill.

Both amplifiers are driven full range so the voltage used by the output devices remains unchanged. The extremely high out of band impedance of the crossiver will limit the current, so could possibly be a benefit.

Struggling to see how that could affect sound quality in a possitive way. I thought doubling up the power supplies might help but seeing as how both amplifiers are running full range I can't really see how.

 

[jiggyjoe]

I did have a go going active with my old mordaunt short ms20i pearls using my arcam a85/p85 combo and an in car electronic crossover. Sounded pretty good but had some humming issues. Used REW to match the response as close to the passive version as possible.

if i was going to have a go at active again id probably go 2 way using the hypex plate amps with built in dsp crossover.

 

[jiggyjoe]

I passive biamp my monitor audio rx6 and it definately sounds better at high volume this way. Although the crossover split is different from a 2 way. One amp drives the upper bass driver and tweeter, and the other amp drives the lower bass driver only. Doing it this way makes the impedance load on the amps considerably easier than if driving them with one amp.

 

[Blacksabbath25]

If it was me Andrew I would stick with passive speakers and save up for a really nice set of passive speakers to go with your lovely hagal amp . Can you do bridging mode with the hagal ? Because like you said about me that would be good for me too to do the bridging thing too

 

[Vladimir]

I think the kit for arround 2K is an excellent value. You are getting A LOT of speaker for that money and best to start with a passive setup, perhaps experiment and have fun later on.

 

[Andrewjvt]

For creating an active speaker with external amps, get one of these http://www.music-group.com/Categories/Behringer/Power-Amplifiers/Studio-... as you need.

Sorry the links aren't active (You will need to copy & paste) as the spam filter blocks the post with them in. (It seems the spam filter only allows spam through, not genuine posts)

Hope this helps

Bill

Will read later

 

[Andrewjvt]

I think the kit for arround 2K is an excellent value. You are getting A LOT of speaker for that money and best to start with a passive setup, perhaps experiment and have fun later on.

Going to build this one passive for sure

 

[Andrewjvt]

If it was me Andrew I would stick with passive speakers and save up for a really nice set of passive speakers to go with your lovely  hagal amp . Can you do bridging mode with the hagal ? Because like you said about me that would be good for me too to do the bridging thing too

No i dont need to. I mentioned bridge mode for your case with 2 abrahamsen amps so you can have 250w per channel and more volume.

As well as bragging rights to one of the meanest power supply on the forum

 

[plastic penguin]

Andrew. Why? How's this sea change come about? I know you were exploring the concept of actives but....

Must say I'm surprised you're looking to ditch your current system.

 

[Andrewjvt]

Andrew. Why? How's this sea change come about? I know you were exploring the concept of actives but....

Must say I'm surprised you're looking to ditch your current system.

No not getting rid of anything but am building k100s and was exploring if i could turn the 100s into an active speaker design using my current amp and maybe adding a few more. If that makes sense

 

[davedotco]

I passive biamp my monitor audio rx6 and it definately sounds better at high volume this way. Although the crossover split is different from a 2 way. One amp drives the upper bass driver and tweeter, and the other amp drives the lower bass driver only. Doing it this way makes the impedance load on the amps considerably easier than if driving them with one amp.

Is an unusual design.

There is a lot going on with different drivers and ports but overall the impedance does not look that difficult, though if the amplifiers are struggling in normal mode then bi-amping might give the amps an easier ride.

Perhaps your amps struggle to produce the required current...?

 

[Benedict_Arnold]

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.

NO - the amplifer circuit is NOT drawn. The Polk speakers in question do indeed have two sets of input terminals. Look at their pictures on line.

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.

NO - you can connect bi-wireable speakers to two completely different (brand, model, valve vs transistor, wattage, case colour, you name it) power amps, one for HF, one for LF, and in extremis you can use as many mono power amps as you have speaker terminals to connect them to.

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.

No again - see above.

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

NO again - if you use different power amps for HF and LF how are the circuits the same?

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.

Yes but it's a lot easier just to take the little brass strips off the terminals. That's why they're there. And my point still stands. Remove the brass strips, connect one pair of speaker wires to pone pair of terminals and all you'll get is either all HF or all LF.

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.

See above. You're wrong.

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.

At last you're right about something, but the same is true for bi-wireable speakers with the little brass links.

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.

You can also use different power amps for HF and LF, and as I said, in extremis use separate mono power amps for each pair of speaker terminals available. Doing so enables one to double (or treble or ...) the power available to the speakers. BTDT.

 

[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.

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.

Next you'll be telling me electrons travel from positive to negative and that centrifugal force is real.

A passive crossover does NOT split the signal at all.

It merely reduces (but not necessarily eliminates) one end of the spectrum from reaching the speaker cone in question. In fact it doesn't even do that. The impedance of a capacitor drops (exponentially?) as frequencies increase, and is theoretically infinite to a DC signal (until the potential reaches the point where the dilectric breaks down and the capacitor shorts out), so the capacitors reduce the LF signals going to the tweeters. They are placed in series with the tweeters for this reason. On the flip side, the impedance of a coil rises (exponentially?) with frequency so HF frequencies are blocked from going to the woofers.

Most crossovers also include a coil in parallel with the tweeter and a capacitor in parallel with the woofer to provide a "short circuit" for the LF and HF frequencies respectively as well, helping further reduce the unwanted elements reaching the woofer or tweeter as appropriate.

 

[Vladimir]

Klik

 

[davedotco]

Before continuing I suggest you aquaint yourself with the "first law of holes".

The basic design of crossovers (or filters) is simple and well known. As I said above, if you do not understand the subject, amply illustrated in your post #41, best not to comment.