EDIT: don't know how i got 10l for a tweeter. Must have mixed it up with cubic centimeters and just didn't know that was way too much.
I'm building something similar to Troel's 3-way designs here, here and here.
My question, is that if the woofer and tweeter share an enclosure, as they do in his designs, does the recommended volume for the woofer enclosure suffice, or do you add the volume recommended for the tweeter?
So if a woofer requires 40 liters, and a tweeter requires 10 liters, do you make the enclosure 40 or 50 liters?
I'm building something similar to Troel's 3-way designs here, here and here.
My question, is that if the woofer and tweeter share an enclosure, as they do in his designs, does the recommended volume for the woofer enclosure suffice, or do you add the volume recommended for the tweeter?
So if a woofer requires 40 liters, and a tweeter requires 10 liters, do you make the enclosure 40 or 50 liters?
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All those 3 tweeters have their volumes encapsulated so they
don't have any extra requirements. They are tuned to a certain
frequency and you can see it in its impedance plot. Your main
concern is to choose the XO frequency and roll-off in a fashion
that they can withstand power input without getting fried in a
frequency region of relatively low distortion.
don't have any extra requirements. They are tuned to a certain
frequency and you can see it in its impedance plot. Your main
concern is to choose the XO frequency and roll-off in a fashion
that they can withstand power input without getting fried in a
frequency region of relatively low distortion.
If the two, or more, speakers require 40Litres and 10litres, then they require separate enclosures of 40Litres and 10Litres. They cannot be combined into a common enclosure of 50Litres.
SS-3WC
The holes in the mid brackets on the left make it appear as if the bass woofer and the tweeter share the volume, with only the mid woofer sealed.
Same here with the SBA-3WC
And here with the AT-3WC
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Tweeter volume is so small it isn't usually taken into account, so YES woofer and tweeter share the same box if the tweeter has a sealed back although some of us sometimes enclose it if we think the box needs stiffening in and around that area but generally not needed
Edit
No tweeter that I know of would ever need 10 litres of box volume, some larger midranges would if operating close to their pistonic range :ie close to resonance but even open backed tweeters would need only about 5cc or so of enclosure
Total box volume is the sum of the individual needs of the drivers, so if you had a woofer needing 40 litre + a midrange needing 10 litres then the total internal volume needed would be 50 litres and external vlume would of course be greater due to the wall thickness etc
Edit
No tweeter that I know of would ever need 10 litres of box volume, some larger midranges would if operating close to their pistonic range :ie close to resonance but even open backed tweeters would need only about 5cc or so of enclosure
Total box volume is the sum of the individual needs of the drivers, so if you had a woofer needing 40 litre + a midrange needing 10 litres then the total internal volume needed would be 50 litres and external vlume would of course be greater due to the wall thickness etc
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Cool, thanks for clearing that up. I initially made a design similar to above where i added the tweeter volume but I now fear this will make the overall volume for the woofer (a 10" BTW) too great. It's about 5+ liters extra, should that cause issue?
PS don't know how i got 10l for a tweeter. Must have mixed it up with cubic centimeters and just didn't know that was way too much.
Let's separate theory from effective. 🙂
In theory, every single cubic millimeter in a box volume is important. So, if you use an internal crossover, or sealed tweeter, additional bracing, etc. it all needs to be subtracted from the box volume.
In practice however, boxes tend to be much more forgiving than you'd think, and prediction of response less precise than we'd want and drivers may vary from sample to sample. Adding wadding may add effective volume as well, up to around 12-15% at most. Same for thick damping panels like Sonic Barrier. However the final result is found only by testing. Throw the room in and it all the modelling starts to seem pointless. 🙂
I usually just look at the total volume and see how much of a difference I'm making. Unless I'm reducing the volume by 10% or more, I don't care.
Best,
Erik
In theory, every single cubic millimeter in a box volume is important. So, if you use an internal crossover, or sealed tweeter, additional bracing, etc. it all needs to be subtracted from the box volume.
In practice however, boxes tend to be much more forgiving than you'd think, and prediction of response less precise than we'd want and drivers may vary from sample to sample. Adding wadding may add effective volume as well, up to around 12-15% at most. Same for thick damping panels like Sonic Barrier. However the final result is found only by testing. Throw the room in and it all the modelling starts to seem pointless. 🙂
I usually just look at the total volume and see how much of a difference I'm making. Unless I'm reducing the volume by 10% or more, I don't care.
Best,
Erik
I'm not sure if this was clear, but drivers should share a space IF and only IF they are driven by the identical electrical signal. So, woofers for the same channel (in series or parallel) may share a volume. You need double the volume though. 🙂 Most box simulators will do this calculation for you, including helping you to consolidate a port if desired.
However, as soon as the drivers sharing a space have different signals applied all this goes away. That is, your L and R woofers should not share an acoustical volume nor should a mid and woofer or mid-woofer and woofer as in a 2.5 way.
There is some interesting work that has been done to mix a mid and woofer in the same volume, but doing so is a purely academic experiment with little upside. One of the big negatives is that you greatly reduce the dynamic range of the midrange.
However, as soon as the drivers sharing a space have different signals applied all this goes away. That is, your L and R woofers should not share an acoustical volume nor should a mid and woofer or mid-woofer and woofer as in a 2.5 way.
There is some interesting work that has been done to mix a mid and woofer in the same volume, but doing so is a purely academic experiment with little upside. One of the big negatives is that you greatly reduce the dynamic range of the midrange.
Although a lot of early Japanese speakers did have the mid and woofer sharing the box space, in the speakers I have opened for spare parts drivers the "Woofer" was rolled off low with a single inductor in-line.
Quite often a reasonable 8 inch bass/mid with a 10 inch woofer and a lot of fibreglass stuffing.
Probably not what we would consider doing these days but I've done it for party speakers when in a hurry, not Hi-Fi but it works
Quite often a reasonable 8 inch bass/mid with a 10 inch woofer and a lot of fibreglass stuffing.
Probably not what we would consider doing these days but I've done it for party speakers when in a hurry, not Hi-Fi but it works
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