Cheap 3-way speakers or expensive 2-way?

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#42
To be perfectly honest Troels' Scanspeak three way classic would be an excellent build. It does pretty much what we want it to do.

Why the scanspeak one?

Well the SEAS drivers do not have shorting rings or any kind of motor linearising strategy in place besides their pole geometry. This has been one of SEAS prestige range short comings for a while now, luckily they appear to be sorting this out with the new drivers they release into the range.

The SB drivers are half way there. The tweeter and woofer both have copper within the gap and this results in drivers that punch well above their price point in terms of distortion, especially with regards to the woofer. The midrange however, the SB12MNRX25-4, contrary to what Troels says, does not. This is an extremely odd decision made by SB as it results in significantly higher third order distortion than you'd want.

You can see how it compares here.

SBAcoustics-SB12MNRX25-4-HD.gif


Zaph's measurement of the SB12 vs the SB15..

SBAcoustics-SB15MFC30-8-HD.gif


You can clearly see the difference.

If the SB12 had shorting rings/copper in the gap it would be an amazing driver, sadly it does not and as a result it's simply run of the mill. There are many drivers out there I would use in its place, in fact I wouldn't ever use the SB12 just because of this omission. Why should I when other drivers outperform it?

This is why I would choose the scanspeak version. All the drivers are inductance linearised and most importantly the midrange and tweeter are (not that it's necessary for tweeters mind you, but it IS for midrange and woofers). Woofers if used in three ways and crossed low, don't always need it as the rising distortion with frequency can be completely bypassed, but it's always nice to have.

I am not usually a fan of Troels' designs, due to certain design choices he seems to work around, but the classic series buck this trend and I whole heartedly recommend them. Obviously the scanspeak one as an objective preference, with the SB coming in as my second choice and then the SEAS as the third.
 
#43
5th element said:
I wouldn't exactly go that far. It is scientific fact, proven both by simulation and then practical implementation that multiple sub approaches are excellent at controlling the modal region of a small listening rooms.

It is also scientific fact that controlled directivity, either by wave guides, driver configuration (a la B&Os latest beolab) or implementation (dipoles) are an excellent way of attending to the other issues that a room can present itself with. Most notably the wave guides or beam width steering from the beolab.

From the point of view of what we hear, an uneven bass response is extremely unpleasant, especially if you want (and you should want) a system capable of extension down to the limits of human hearing. Smeared, imprecise imaging with tweeters that call attention to themselves and spitty treble are a product of early room reflections and wide dispersion and are extremely unpleasant. Wave guides specifically help manage these and you don't need much of a wave guide to get appreciable results. The SEAS DXT tweeter doesn't control directivity very low in frequency but already you can appreciate what it does. Going bigger only improves things further, but it's mainly the upper frequencies that benefit the most as these are where we get our localisation cues from.

The 100-400Hz issue? What issue? Take your subs up to 150Hz for a start. With multiple subs localisation becomes far less audible, no sub produces a tremendous amount of output by itself so doesn't draw much attention to itself. I run 150Hz and have a sub right next to the listening position to the side wall and cannot hear it - ever -. The higher up you go the far less of a problem modes become because they are so tightly packed.

Then you've got floor bounce and to a less extent ceiling bounce. You can eliminate floor bounce with floor mounted woofers in three ways. With a floor mounted woofer the bounce to the ceiling and back down is pushed lower in frequency to the point where the multiple subs cover it up.

If you're going to choose to worry about early reflections relatively low in frequency grab yourself a cardioid or a dipole to cover from 150Hz and up to wherever you want it to hand off.

All of these things are more attractive to me than any kind of room treatment. The goal, imo, is to have a system that goes into your room -without- you needing to modify the room in any way to get the sound that you want. People often say that the room plays an extremely important part in how your system will sound, but this is only because your system interacts far too much and in the wrong way with the room.



I get the impression that you're not. Trouble is I'm only a proponent because it works, both on paper/technically/scientifically as to why it works and in principle when you actually implement it properly.
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your clearly confuse about room treatment.

you dont understand what bass traps and early reflections panels do.

cardioid bass, multiple subs. or any type of speaker design will not change the physics of in-room bass.

waveguides do not eliminate early reflections, only limits them

and multiple subs do not eliminate resonance under the modal region, they can only help to acheive flat FR, and do nothing for resonance

Waveguide + mulitple sub is a good approach, but in no way eliminates the benefits of a well professionally treated room.
and can we stop the myth that a treated room is dead. a well treated room is natural, not dead.
a untreated room, and I dont care how many ******* rugs you have or sofa, is overly bright and reverberate and not natural in the slightest.
 
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