All,
I'm looking at building a pair of computer (near field) speakers which are reasonably compact but also have decent bass. Having built a number of designs previously the ones that work best are the 2.1 design (full range driver crossed over at 80Hz with a sub). This time around I'd like to build a pair without the sub with the aim to maximize the bass response to replace a design using W3-871S speakers that do a reasonable job but the bass is poor.
So the challenge is to get as much bass from a 3" driver without resorting to a subwoofer or a large box (5 to 7L ideally), and prefer to have it run full range if possible. Quite difficult to do but am willing to compromise top end response or distortion specs if needed.
Doing research on this topic has come up with several considerations:
- Sealed box using a Linkwitz transform, but needs a driver with high x-max and high power capability.
- vented box but will require a driver with high x-max and a high pass filter below the resonant frequency to avoid distortion & possible damage with such a small speaker.
Looking at Zaph's small driver test was very helpful and the clear winner for this application is the Aura NS3-193-8A / Dayton ND90, which has decent lower frequency response and huge x-max for such a small driver. Punching the TS parameters into WinISD shows that I can run this driver with a 6 or 7L box with a tuned port and get down to about 40Hz, which would be perfect. Also feedback about this driver and its bass response is very positive, and its high frequency response up to about 15K is decent although the distortion is a little higher than equivalent drivers according to the Zaph tests.
I think the vented option is the preferred approach (a LT sealed design has the potential to blow the driver) but I'm not sure how this driver would work vented as its so small and most designs I have seen for it are sealed. Also I'm not sure if the WinISD results are correct for a small driver in a vented box.
For those with more experience in speaker design I have a couple of questions:
- Is it practical to have such a small driver running vented & get reasonable performance?
- Am I correct that sealed LT won't work and vented is better for extended bass (even though transient response suffers)?
- Can I trust WinISD results with such a design?
- What T&S parameters apart from xmax are important for extended bass from a small driver?
- Are there any other drivers that I could consider for this application (small box, extended bass)?
Anything else I should consider? Thanks for the feedback!
I'm looking at building a pair of computer (near field) speakers which are reasonably compact but also have decent bass. Having built a number of designs previously the ones that work best are the 2.1 design (full range driver crossed over at 80Hz with a sub). This time around I'd like to build a pair without the sub with the aim to maximize the bass response to replace a design using W3-871S speakers that do a reasonable job but the bass is poor.
So the challenge is to get as much bass from a 3" driver without resorting to a subwoofer or a large box (5 to 7L ideally), and prefer to have it run full range if possible. Quite difficult to do but am willing to compromise top end response or distortion specs if needed.
Doing research on this topic has come up with several considerations:
- Sealed box using a Linkwitz transform, but needs a driver with high x-max and high power capability.
- vented box but will require a driver with high x-max and a high pass filter below the resonant frequency to avoid distortion & possible damage with such a small speaker.
Looking at Zaph's small driver test was very helpful and the clear winner for this application is the Aura NS3-193-8A / Dayton ND90, which has decent lower frequency response and huge x-max for such a small driver. Punching the TS parameters into WinISD shows that I can run this driver with a 6 or 7L box with a tuned port and get down to about 40Hz, which would be perfect. Also feedback about this driver and its bass response is very positive, and its high frequency response up to about 15K is decent although the distortion is a little higher than equivalent drivers according to the Zaph tests.
I think the vented option is the preferred approach (a LT sealed design has the potential to blow the driver) but I'm not sure how this driver would work vented as its so small and most designs I have seen for it are sealed. Also I'm not sure if the WinISD results are correct for a small driver in a vented box.
For those with more experience in speaker design I have a couple of questions:
- Is it practical to have such a small driver running vented & get reasonable performance?
- Am I correct that sealed LT won't work and vented is better for extended bass (even though transient response suffers)?
- Can I trust WinISD results with such a design?
- What T&S parameters apart from xmax are important for extended bass from a small driver?
- Are there any other drivers that I could consider for this application (small box, extended bass)?
Anything else I should consider? Thanks for the feedback!
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Joined 2009
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this has worked well for me
http://www.diyaudio.com/forums/full-range/175056-martello-enclosure-fr88ex.html
You want good bass from a 3"er, which is an oxymoron. However, Psychoacoustics tells us that you only need to get to 80Hz to "hear" the bottom end of all acoustic instruments. The complete harmonic series of, say, the double bass lies above 80 Hz. Our brains recreate the fundamental from for the harmonic series. What you will never get from a 3" driver is slam. Forget it.
Bob
Bob
If the Qts of the driver is below about 3, you can maximise the bass by using a 5th order quasi-butterworth alignment. See here: Satellites and Subwoofers
You'll need to apply some equalisation, but the filter required does provide a high-pass function to reduce below-resonance excursion.
You'll need to apply some equalisation, but the filter required does provide a high-pass function to reduce below-resonance excursion.
Hi Melo, what are the make/model of these and did you compare them to the NS3?
Don, I'm not quite clear about quasi 5th order butterworth, seems its tuning a larger box to extract the last bit of bass - however the NS3 drivers have a Qts of about 0.7 which is too high according to the tables at Elliot Sound (and I don't have the desk space for a larger box).
I think I might be stuck with a classic vented design, as I would run out of headroom pretty quickly with a LT sealed design forcing the bass.
Don, I'm not quite clear about quasi 5th order butterworth, seems its tuning a larger box to extract the last bit of bass - however the NS3 drivers have a Qts of about 0.7 which is too high according to the tables at Elliot Sound (and I don't have the desk space for a larger box).
I think I might be stuck with a classic vented design, as I would run out of headroom pretty quickly with a LT sealed design forcing the bass.
Dayton Audio RS100-4 4" Reference Full-Range Driver 4 Ohm 295-378
These are in Zaph's tests.
They are definitely better.
4mm xmax, copper cap, low inductance, phase plug.
I did an aperiodic. But you could port them.
They also have a far lower Qts. More port friendly.
No BOOM BOOM!
3.28 lt. F3=64 hz
That's for flat alignment. You could port lower with a larger box for a critical Q.
These are in Zaph's tests.
They are definitely better.
4mm xmax, copper cap, low inductance, phase plug.
I did an aperiodic. But you could port them.
They also have a far lower Qts. More port friendly.
No BOOM BOOM!
3.28 lt. F3=64 hz
That's for flat alignment. You could port lower with a larger box for a critical Q.
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Thanks Melo.
These drivers are a little bigger than 3" but still workable. I can model them to roll off below 50Hz with a 5.5L box which is quite nice, and a smaller box than the NS3 (according to WinISD), and their extra sensitivity makes up for the smaller xmax. They are quite similar to the NS3 but have a distinct advantage of lower distortion although a bit more expensive and needs a notch filter at 12Khz. Did you compare the sound quality with the NS3? Will definitely look into this driver.
These drivers are a little bigger than 3" but still workable. I can model them to roll off below 50Hz with a 5.5L box which is quite nice, and a smaller box than the NS3 (according to WinISD), and their extra sensitivity makes up for the smaller xmax. They are quite similar to the NS3 but have a distinct advantage of lower distortion although a bit more expensive and needs a notch filter at 12Khz. Did you compare the sound quality with the NS3? Will definitely look into this driver.
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deandob.... getting amazing bass from these W boxes; I'd be temped to try it with a 3" driver.
pics #28 - #32..... They were tuned on the bench to 60hz.
http://www.diyaudio.com/forums/full-range/217121-please-recommend-desktop-fullranger-3.html
I'm going to see if I can record on a 10 sec clip on a good 2 mic cam corder... it is hard to believe the big box sound.
pics #28 - #32..... They were tuned on the bench to 60hz.
http://www.diyaudio.com/forums/full-range/217121-please-recommend-desktop-fullranger-3.html
I'm going to see if I can record on a 10 sec clip on a good 2 mic cam corder... it is hard to believe the big box sound.
Oh long story to this point... built a table full of boxes with this driver (FF125wk), all slightly different. This last pair will have you running around the room looking for a subwoofer. It's a nice bass also, which does not sound faux.
Listening to wide rage of music, some sound like you are wearing headphones...some other are just okay. E.g. put the Nylons on last night, played that about 3 times...wow (headphone sound).
Using a small BSC, need to add cap next.
Listening to wide rage of music, some sound like you are wearing headphones...some other are just okay. E.g. put the Nylons on last night, played that about 3 times...wow (headphone sound).
Using a small BSC, need to add cap next.
Here is a 3 inch driver. Quite happy, but as the real size is 2 and a quarter, there is no bass. 100Hz and that is all there is to it. Modified Fountek FE85's. Trying to EQ something this small is how you learn about Xmax the hard way. And distortion.
If one heads over to Linkwitz, they can read all about how to calculate the amount of air one has to move for a bass frequency and how much power that takes. These move a couple of mm. To get what I call bass, they would need to move about a foot. I think they can only do that only once.
If one heads over to Linkwitz, they can read all about how to calculate the amount of air one has to move for a bass frequency and how much power that takes. These move a couple of mm. To get what I call bass, they would need to move about a foot. I think they can only do that only once.
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