Why do you need a speaker crossover - discuss

[Marco]

Sorry Marco.. I just find it all very very frustrating!

So leave it there then, Nat - and that applies to you too, Richard. Or just ignore each other, as I will not have this site littered with tedious and banal circular arguments!

Marco.

[Dr Bunsen Honeydew]

In answer to the OP; for high quality, full range reproduction you need a 3 way system (at least). Whether driven actively or passively you will therefore need a crossover.

For a non full range system, then you can get away with a single driver. My Hacker Sovereign II radio makes a very nice & enjoyable sound with a single AlNiCo powered Goodmans Elliptical driver. I've also heard & owned engaging back loaded horns with Lowther & other drivers. But a complete solution? I don't think so. I don't really like asking any driver to cover more than 3-4 octaves.

There is scope to address some driver resonance by mechanical means. It isn't a free lunch though. For example I'd suggest that a speaker like the ES14 suffers as much by the nature of its cone as it benefits from the absence of a crossover feeding it.

All imho. YMMV

There is scope for addressing a lot of it, it depends how you do it. As I have said before in the thread I am not talking about single driver speakers, they don't have a crossover by nature. I am in this case talking about two way, I suppose it could conceivably (but no by me) be applied to three way. Cone doping is only part of it. Driver position has a lot to do with it as well and how the driver interacts with the acoustic.

You have far more experience of horns than I have, and how do you dope a horn (the mind boggles). So I see no other course than bi-amp or active or crossover. Re the ES14 I know little apart from what I have been told having never used them.

None of this is absolute, I am simply saying that there are ways of removing the majority of complex crossover elements by mechanical means in selection and design of drive unit and with after market doping of those drivers and also with cabinet design and speaker drive unit alignment.

I will give you an analogy *IF* it was possible to remove and no longer need your output transformer with your current circuit (i.e. not using the current OTL circuit which I think we agree is a bit dodgy) would you not do it. For me this is the same, if you can get the bloody thing out of the way of the music then do it.

[hifi_dave]

I think the point is being lost here somewhere down the line. Do you accept that any component in the signal path will damage the music? If so by altering the selected driver mechanically to remove that component can only be a good thing - agreed? So you have heard good speakers with a crossover, and so have I, but to follow the argument the speaker would have been even better without those components in the signal path and if the job had been done mechanically.

The only way to have no component in the signal path is to listen to live music. Hi-Fi equipment is full of components.

The best speakers I have heard have had crossovers and I've also heard some horrors with. The nastiest speakers I have heard were single drivers.

Surely you can't create two way speakers where the drivers have different efficiencies without a component or two ? It can't all be done mechanically, can it ?

[Dr Bunsen Honeydew]

The only way to have no component in the signal path is to listen to live music. Hi-Fi equipment is full of components.

The best speakers I have heard have had crossovers and I've also heard some horrors with. The nastiest speakers I have heard were single drivers.

Surely you can't create two way speakers where the drivers have different efficiencies without a component or two ? It can't all be done mechanically, can it ?

Dave please read the thread, the first post explains it.

Driver selection addresses the sensitivity issue, and a simple blocking cap protects the tweeter, that is not a crossover, it is protection. For me the definition of a crossover is the desire to tailor the response of the drivers electrically via passive components configured as filters. I am saying that tailoring *can* be done mechanically and to my ears having compared a version with crossover with a version doped, it has made one hell of a difference.

[pure sound]

You can look at it the other way round. Someone might feel that a carefully implemented crossover or a well designed output transformer (for example) were tools that might be used to take advantage of the particular attributes of a drive unit or a particular output device like a Direct Heated Triode and without them the benefits of those items might not be realised.

With regard to horns, you wouldn't dope the horn. You'd hope that it was fairly inert though. However it will still have a driver behind it and that might benefit from mechanical treatment in just the same way as it might in a conventional direct radiator. Indeed the profile of the horn chosen might be used to extend or limit the bandwidth or sensitivity of a particular driver by strictly mechanical means!

With drivers dozens of different cone materials and profiles have been tried. Trying to control cone behaviour & break-up invariably seems to involve adding mass in one way or another. ie heavier, stiffer materials, ribs, doping etc. These treatments certainly will alter the sound just as applying correction via electrical means will. I still keep going back to paper cones which, when they do misbehave, do so in what seems a predictable & natural way. Adding mass will compromise the fineness of their resolving power though.

I suppose the reason I like multi-way horns is that when used with drivers having lightweight diaphragms & powerful magnets, they can produce adequate SPLs with the minimum of cone movement so a reduced chance of distortion through diaphragm deformation or through the voice coil having to move in the less linear parts of the magnet gap.

With regard to the directly driven electrostatics, its an intriguing idea & I'd like to hear them if only to learn whether it addresses my reservations about electrostatic loudspeakers. Having seen some of Nick's other work (well pictures of it) I'm sure he's more than capable of implementing it safely. I'm not sure it'd ever be a commercial product but then people do make plasma tweeters so who knows?

EDIT. I did once hear some Beveridge System 2's which had 200W valve amps built into the bases and which may have been directly coupled. They were by far the most impressive electrostatic speakers I've heard, not without flaws but head & shoulders clear of the usual Quads & Martin Logans.

[Dr Bunsen Honeydew]

You can look at it the other way round. Someone might feel that a carefully implemented crossover or a well designed output transformer (for example) were tools that might be used to take advantage of the particular attributes of a drive unit or a particular output device like a Direct Heated Triode and without them the benefits of those items might not be realised.

Then they are necessary, that is not the point of this thread. They will become unnecessary when an individual finds a way to do without them. In that case would you hang on to them just for the sake of it.

The rest of your post I agree with.

[pure sound]

By the way Richard, I completely agree with your opinions on the old BBC style monitors. Horrible, slow, sounding things with nasty plastic cones & hugely complicated crossovers. Quite capable of squeezing the life from any piece of music!

I think what AR, Allison & Snell did on the East Coast of the USA was far more interesting.

[Macca]

What about a loudspeaker with a full range driver covering the presence band, a self protecting tweeter and a seperate bass enclosure with a dedicted bass driver and built in amplifier that only delivers power through the 10 hz to say 80 hz range? - that gives you a wideband 3-way speaker with no crossover components.

We have also not addressed the crossover point - sticking the crosover at 2.5khz or 3khz slap in the middle of the performance range is where the crossover will have the most deletorious effect.

[Ali Tait]

Explain safety interlocks (in this context) to me.

You'd have to ask Nick for the details, but as I understand it, if there is a problem within the amp, or one of the speaker lead connections is broken, the HT will be switched off.

[Dr Bunsen Honeydew]

By the way Richard, I completely agree with your opinions on the old BBC style monitors. Horrible, slow, sounding things with nasty plastic cones & hugely complicated crossovers. Quite capable of squeezing the life from any piece of music!

I think what AR, Allison & Snell did on the East Coast of the USA was far more interesting.

Thank goodness for that I don't feel so alone