Theoretically, a (box) speaker can have crossover at the baffle step frequency. What would be advantages and disadvantages of such a design?
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In a passive speaker you can "equalize" the baffle step by chosing corresponding driver sensitivities or simply by attenuating the upper driver with resistors/L-pads. That is usually much cheaper than big inductances.
You could even adapt the speaker to different positioning by changing L-pads or (for active systems) adjusting levels.
The only "disadvantage" I can see is that you cannot freely chose (and change) the crossover frequency. It's bound to the baffle width.
2.5 way is a way to allow this while keeping the crossover separate. It's fairly easy to make it work.
One advantage is not losing up to 6dB of driver output
A disadvantage is high passing a driver much higher than it's linear bandwidth would require otherwise
As an example, high passing a 225mm woofer at around 300 to 400Hz to avoid baffle step loss, forces the driver out of the operating range which it's typically best at reproducing, relative to smaller drivers.
Thank you for the responses!
Looks like there are advantages, provided the combo of the baffle width and the xo frequency is not an afterthought and therefore does not over constraint the drivers around the xo into uncomfortable f range.
What about the steepness of the baffle step slope - what is it determined by? Designer should be taking the step slope as one of the inputs into the xo design.
Looks like there are advantages, provided the combo of the baffle width and the xo frequency is not an afterthought and therefore does not over constraint the drivers around the xo into uncomfortable f range.
What about the steepness of the baffle step slope - what is it determined by? Designer should be taking the step slope as one of the inputs into the xo design.
Yes there can be some advantage.
As already pointed you might loose less output on the mid.
Ime not the theorical full 6db but in the 2/3db range - depend from the bsc needed in place -you rarely need the full 6db compensation as boundary are often close enough to have an effect) and it'll depend of the width of your box/ center frequency of bsc.
Another thing often overlooked and which have not been stated here either is relative to directivity behavior: once you are above bsc center freq the box start to have an effect on driver directivity, narrowing it.
It might or not be an advantage, depend on your design goal.
As an example D&D 8c use the box width ( hence bsc) to achieve a smooth transition from the cardio loading to the waveguide directivity.
Of course it's a global approach taking into account box width+driver own directivity behaviour.
As already pointed you might loose less output on the mid.
Ime not the theorical full 6db but in the 2/3db range - depend from the bsc needed in place -you rarely need the full 6db compensation as boundary are often close enough to have an effect) and it'll depend of the width of your box/ center frequency of bsc.
Another thing often overlooked and which have not been stated here either is relative to directivity behavior: once you are above bsc center freq the box start to have an effect on driver directivity, narrowing it.
It might or not be an advantage, depend on your design goal.
As an example D&D 8c use the box width ( hence bsc) to achieve a smooth transition from the cardio loading to the waveguide directivity.
Of course it's a global approach taking into account box width+driver own directivity behaviour.
Yes you have to take it into account right from the start of the project if you want to play with it whatever the game ( very wide box, medium or narrow...).
Better plan than being sorry. 😉
Steepness is a locked parameter. 4 octave wide shelf ( with center freq in the midlle of this 4 octave range).
The amount of gain ( i prefer cut than boost) is location dependant as boundary play a role.
https://trueaudio.com/st_diff1.htm
Isn't it dependant from the driver type and what you plan to accomplish?
I mean a 8" mid can suffer from being cut ( high passed) at 400hz, but if it is a low mid/sub then...?
Another example could be to use a 12" as mid woofer high passed (for directivity purpose and mid frequency 'tactilness') to xover circa 1200hz to a constant directivity waveguide to have a smooth transition.
Typical econowave approach.
I would say none, but you may need to reword the question, as it is unclear what exactly you are asking.
Here is a documented example of use of bsc (through box width) to lessen demand on mid driver:
http://www.troelsgravesen.dk/Acapella_WB.htm
http://www.troelsgravesen.dk/Acapella_WB.htm
XO best placed at somewhere between 0.707 ≤ Fbs(-3)=f0 ≤ 1. I have had success for numbers lower in the range.
dave
especially if you are not chasing the absolute deepest octave of bass response possible.