Fast midrange driver

Chuck, among others, you need to read up on this. Filters do not change the mechanical properties of drivers. They only modify the signal sent to them. Sorry, to be rough.

I suggest the AES papers starting in the 1950's where this was all described. Time better spent than reading some glossy magazine inventing terms, advertising copy writer, or some blogger who knows less than you. It is physics. Just physics. Newtonian physics.
 

Brett

Member
2002-01-07 6:02 pm
Newtonian physics.
Really? I just read a white paper from a cable manufacturer explaining how their cables used quantum tunneling to enhance electron propagation through the conductors, resulting in improved resolution. Some reviewers even described it as lifting many veils.

Thinking they might be onto something, I bought a pair of interconnects and installed them un system unbeknownst to the wife. As she walked through the front door later, when I was listening to Famous Blue Raincoat, I heard her exclaim loudly and she ran into the room wanting to know what I'd done to the system as it had never sounded so good and 'organic'. She was in such a state, I had to rush her into the boudoir and calm her down. Eventually.
 
I am sure he was being facetious there.
Had to look that up (no native speaker), but glad you got my intentions in some way. But the serious part: ‘fast’ probably only could be defined as high bandwidth and low resonance (Q) behavior. Since midranges mostly are limited by a bandpass filter, I dare say the properties of that filter determine the ‘speed’. And of course all becomes pretty irrelevant when you add it all up to a 3-way and start equalizing response to flat.
 
"The more you limit a drive-unit in the frequency domain, the less well-defined its output wil be in the time domain"
Kal Rubenson Stereophile Nov 2004.

Which is ok and necessary in multiway speaker

Limiting driver frequency response most of the time would improve their audible distortion.

Full range 8 inch would perform poorly below 100hz compared to woofer or subwoofer.

Fullrange 8 inch generally ( and if same cone material used ) also would perform
not as good as proper woofer in 100-400hz region, even when used within the power and and suspension limit.

There is cone/surface distortion, suspension nonlinearity that’s harder to measure but it is there which is a bigger elephant audibly than impulse response.
 
Glossy magazines and serious math... although I wouldn't advocate ranting about Stereophile, since that magazine at least took the effort to publish measurements over the years.

Imho, apart from the correct on-axis execution, 'fast' midrange possibly stems from the directivity characteristics of the system and the resulting in-room response. In modern living rooms sound at midrange frequencies decays rather slowly and the contribution of indirect sound can be quite high. Apart from the effects on directional information in the sound this also could lead to the experience that a speaker sounds 'slow' (never believed I ever would write such a thing :unsure: ). Any ideas about this (I can't recall scientific work on this subject anyway)?
 

Boden

Member
2010-03-02 9:29 am
less well-defined its output wil be in the time domain" For starters : isn't wil with double ll, i.e. will?

What on earth is "well defined" supposed to mean in the context of impulses? So we have "well defined" and "less well defined" impulse responses? Or is this referring to a less than perfect square wave? We can only only guess, but we all know bandwith effects the shape of an impulse.
Vintage Audio Magazine style gibberish, if you ax me.
 
Imho, apart from the correct on-axis execution, 'fast' midrange possibly stems from the directivity characteristics of the system and the resulting in-room response. In modern living rooms sound at midrange frequencies decays rather slowly and the contribution of indirect sound can be quite high. Apart from the effects on directional information in the sound this also could lead to the experience that a speaker sounds 'slow' (never believed I ever would write such a thing :unsure: ). Any ideas about this (I can't recall scientific work on this subject anyway)?

The directivity effect of midrange dispersion in less acoustic treated room would mostly sounds more “fuzzy” and less defined.

However, even in typical
untreated room with moderate high reflections, differences between midrange driver material and construction is still very audible.

Both the room and the driver contributes differently to the perception of the midrange sound.

Also another option and matter of preference:

Smaller, wider dispersion midrange despite their higher room reflection and a bit lesser than ideal cone/surface material also can sound “faster” partly because of the cone/surface noise settles faster and the wider dispersion direct sound also perceived as “faster” and more natural.
 

Brett

Member
2002-01-07 6:02 pm
Smaller, wider dispersion midrange despite their higher room reflection and a bit lesser than ideal cone/surface material also can sound “faster” partly because of the cone/surface noise settles faster and the wider dispersion direct sound also perceived as “faster” and more natural.
I don't agree, and in most rooms have a much stronger preference for narrower controlled directivity to keep spurious reflections and extended decay shorter or at least well outside Haas.
 
I don't agree, and in most rooms have a much stronger preference for narrower controlled directivity to keep spurious reflections and extended decay shorter or at least well outside Haas.
If you have different experience when you listened in your room is fine, whatever works best.

I tried both dispersion profile and both works well if the driver is very good, but with wider dispersion driver the demand for better cone/surface material and motor is less.

I am not a fan of limited dispersions horizontally for 1000khz and up

One lesser discussed and overlooked reason is mid and mid high distortion is higher frequency than fundamental, when using more abrupt off-axis dropoff, the higher frequency distortion’s on-axis sounds is more prominent, hence less natural sounding.
 
Pardon my ignorance, but what exactly is cone/surface noise?
It is non-ideal sound produced by the cone material and geometry combination

Same motor , same cone geometry, same suspension, same equalized response still sounds different between paper cones ( thickness, fibre profile and mix, etc), even more so with differing cone material

Contributing factor:
More or less pistonic or bending in motion,

Brittle/ flexible bend transitions while on action ( eg.paper vs carbon fibre vs plastic ).

Mass, damping

Layering of composites, paper fibre types, resins, damping compound, metal ringing, cone profile, patterning and cuts/grooves, dust cap size and material.

How the cone/surface is driven
(eg voice coil former driven dynamic driver vs planar vs electrostat ).
 
So a limited bandpass filler mid like in a Duelund filter type would be wrong on a time domain behavior... or VS a LR24 classic 3 ways with a larger mid?
I doubt...
Btw I didn’t mention anything about filter time domain response.

Unless using digital filter with phase adjustment, all filter is wrong in time domain response, but in practice it can be less significant factor to achieve optimized final sound, depending on the frequency range it’s applied and dispersion.