This is a project to design & build a high performance 3-way studio monitor with active amp & DSP. F3 target is below 40 Hz, peak volume at that frequency ~105 dB/m. Target crossover is 3~400 Hz. Lower would be nice but not sure if the mid dome can reach down that low.
I have three 10" woofer pairs on hand to consider. Can you help me choose one?
Here are key properties. Fs & Qts were measured; the rest are published.
*Converted from Parts Express USD price per piece in 100 unit min purchase.
My preferred bass loading is closed box rather than ported, likely due to the increased group delay of the latter. Closed boxes are also simpler to build and Vb less critical. However, many high end studio monitors are ported so it appears my preference is unfounded, perhaps having heard too many poorly designed ported speakers over the years. So I remain cautiously open to both ported & sealed designs.
Vifa/Peerless Tymphany NE265W-8 ticks a lot of boxes: Based on WinISD calculations, a 32 liter box ported to 29.4 Hz provides F3 of 35 Hz. Looking at sensitivity, based on RMS power, this should provide 102 dB@1m max at 35 Hz -- or 105 dB at the peak of 250W (assuming no power compression). A sealed box of the same 32 liters pushes Fs to 57 Hz; this is far worse for bass output, and doesn’t match the ported box till 20 Hz at -15.5 dB. The 32 liter box calculated doesn’t include the port volume or driver displacement, which might be as much as 2-3 liters. This combined with a sealed mid chamber might push external dimensions to 40+ liters. The extremely low weight due to the NE265’s neodymium magnet is a plus, along with the advanced frame design, which appears to have inspired Satori bass/mid drivers. However, one serious caveat is that this driver is virtually unobtanium for DIYers due to the 100pc min order imposed by Tymphany these days; I might not be able to make more than 1 pair, which could be a problem.
Dayton Audio RSS265HF-8 is designated as a subwoofer. A 47l box provides Q=0.707 and F3=38Hz, which seems excellent for a sealed box of this size. Reducing box size to 40l provides Q=0.73 & F3 of 39 Hz. I generally prefer the sound of sealed woofers over ported ones, so the 40l box size is OK, and PEQ with the planned Hypex FA253 plate amp could provide even deeper bass performance or equal bass performance in a smaller box. Using the 250W maximum power output of the Hypex FA253, I calculate max SPL at 39Hz in the 40l sealed box to be ~106 dB@1m. The 14.3mm Xmax (if that means ∓14.3mm) promises good responsiveness to bass EQ, too. The high 7.7kg mass, 3X that of the NE265, is the only real downside -- and the fact that it’s a sub driver suggests FR above 100Hz may not be ideal, though factory specs don’t show anything untoward to 500Hz.
An SB Acoustics SB29NRX75-8 isn’t exactly on my shelf, but four of them are used in my LX521-inspired OB 4-way dipoles. A pair could be pulled for development purposes -- and Solen also delivers these pretty fast. A 53l box with SB3 alignment provides F3 = 32 Hz. Good, but the box is a bit too big. Reducing box size to 40l gives F3= 37.5Hz, slighter lower than the Dayton in the same box. Accepting 200W as the power limit, maximum SPL at 37.5 Hz should be ~108 dB, assisted by the higher 88 dB/2.83V sensitivity. One downside of this woofer is its oversize frame (290mm diameter vs ~265mm for the others), which dictates a wider baffle, likely >310mm, whether or not this is needed for the mid + tweeter.
I have three 10" woofer pairs on hand to consider. Can you help me choose one?
Here are key properties. Fs & Qts were measured; the rest are published.
| Woofer | Fs | Qts | Vas | dB/W | RMS MAX | Xmax | Weight | CAD |
| Peerless NE265W-8 | 26Hz | 0.37 | 97l | 85 | 125W 250W | 9.4mm | 2.24kg | $250* |
| Dayton Audio RSS265HF-8 | 26Hz | 0.51 | 52l | 84 | 350W 700W | 14.3mm | 7.7kg | $268 |
| SB Acoustics SB29NRX75-8 | 26Hz | 0.37 | 86l | 88 | 200W | 11mm | 5.4kg | $245 |
My preferred bass loading is closed box rather than ported, likely due to the increased group delay of the latter. Closed boxes are also simpler to build and Vb less critical. However, many high end studio monitors are ported so it appears my preference is unfounded, perhaps having heard too many poorly designed ported speakers over the years. So I remain cautiously open to both ported & sealed designs.
Vifa/Peerless Tymphany NE265W-8 ticks a lot of boxes: Based on WinISD calculations, a 32 liter box ported to 29.4 Hz provides F3 of 35 Hz. Looking at sensitivity, based on RMS power, this should provide 102 dB@1m max at 35 Hz -- or 105 dB at the peak of 250W (assuming no power compression). A sealed box of the same 32 liters pushes Fs to 57 Hz; this is far worse for bass output, and doesn’t match the ported box till 20 Hz at -15.5 dB. The 32 liter box calculated doesn’t include the port volume or driver displacement, which might be as much as 2-3 liters. This combined with a sealed mid chamber might push external dimensions to 40+ liters. The extremely low weight due to the NE265’s neodymium magnet is a plus, along with the advanced frame design, which appears to have inspired Satori bass/mid drivers. However, one serious caveat is that this driver is virtually unobtanium for DIYers due to the 100pc min order imposed by Tymphany these days; I might not be able to make more than 1 pair, which could be a problem.
Dayton Audio RSS265HF-8 is designated as a subwoofer. A 47l box provides Q=0.707 and F3=38Hz, which seems excellent for a sealed box of this size. Reducing box size to 40l provides Q=0.73 & F3 of 39 Hz. I generally prefer the sound of sealed woofers over ported ones, so the 40l box size is OK, and PEQ with the planned Hypex FA253 plate amp could provide even deeper bass performance or equal bass performance in a smaller box. Using the 250W maximum power output of the Hypex FA253, I calculate max SPL at 39Hz in the 40l sealed box to be ~106 dB@1m. The 14.3mm Xmax (if that means ∓14.3mm) promises good responsiveness to bass EQ, too. The high 7.7kg mass, 3X that of the NE265, is the only real downside -- and the fact that it’s a sub driver suggests FR above 100Hz may not be ideal, though factory specs don’t show anything untoward to 500Hz.
An SB Acoustics SB29NRX75-8 isn’t exactly on my shelf, but four of them are used in my LX521-inspired OB 4-way dipoles. A pair could be pulled for development purposes -- and Solen also delivers these pretty fast. A 53l box with SB3 alignment provides F3 = 32 Hz. Good, but the box is a bit too big. Reducing box size to 40l gives F3= 37.5Hz, slighter lower than the Dayton in the same box. Accepting 200W as the power limit, maximum SPL at 37.5 Hz should be ~108 dB, assisted by the higher 88 dB/2.83V sensitivity. One downside of this woofer is its oversize frame (290mm diameter vs ~265mm for the others), which dictates a wider baffle, likely >310mm, whether or not this is needed for the mid + tweeter.
Well, Genelec, K&H/Neumann and ATC (to name a few) use proprietary drivers. From perspective reliability, serviceability and price a pro driver like the FaitalPro is a very good option. But you don’t have to forget the drivers you mentioned, apart from the NE265, which is EOL, as Tymphany is getting out of the DIY business (at least, that is what the DIY business tells us…).
Why do you need to squeeze a 10" driver into less than 40 liters? There is nothing to win by using a too small volume with a large cone in HIFI.
Also an f3 of 40 Hz is not really 10" territory. You should better use some 8" for your "monitor" volume. An 8" will work much better with a dome mid, too.
Anyway, I question this whole, unfounded DIYS hype for dome midrange. There is nothing you can't do just as well and better with a cone midrange. You will never get the dynamics of a good 5" mid cone from some 3" dome chassis. There is some good reasons they have fallen out of favor. Just because lately some marketing guy saw a niche for them doesn't make them better. They are, if done right, sometimes a solution for some special applications, but no universal, superior concept, even as some may think so.
Also an f3 of 40 Hz is not really 10" territory. You should better use some 8" for your "monitor" volume. An 8" will work much better with a dome mid, too.
Anyway, I question this whole, unfounded DIYS hype for dome midrange. There is nothing you can't do just as well and better with a cone midrange. You will never get the dynamics of a good 5" mid cone from some 3" dome chassis. There is some good reasons they have fallen out of favor. Just because lately some marketing guy saw a niche for them doesn't make them better. They are, if done right, sometimes a solution for some special applications, but no universal, superior concept, even as some may think so.
Reliability & serviceability are important, I see your point. But this project is more likely to be a one-off (or few-off
), not some kind of production run, never mind how short. It's for friends.I have to admit the 13.5mm Xmax & 400W AES power is enticing.
Practical usability in small mixing studios where <40Hz reach is still desired. Accuracy is #1, but it's not exactly hifi, afaik. Typical monitor size in my friends' studios is 12x18" with ~15" depth. They would like an enclosure that isn't much bigger.
It is not just any dome but the the 3" Beryllium JA0801 from the Yamaha NS1000. It reaches 500Hz in stock form & I'm modding the backside to lower the Fs to <300Hz. I've had them for a few years; the itch is on to make something of them.
I appreciate that there are likely other 10" woofers that could fill the role and perhaps better, but I am asking specifically (at least to start) which of the 3 10"s on my shelf you would choose for this project?
Note that the Dayton RSS265HF-8 is a pretty robust driver & PE actually recommends 1.1' sealed for f3=40Hz -- not so different from the SDX-10 in this aspect.
While decreasing the resonance frequency is nice, typical midrange domes don't have the volume displacement to support high output and low cross points simultaneously. I couldn't find specs on the NS-1000 mid in a quick search, but I'd be cautious trying to push them lower.
Is this sealed for the SB29? If not, F3 of 37.5 ported vs F3 39 sealed is kind of an unfair comparison to the Dayton. That 1.5hz is irrelevant but the sealed will have a much better F6 and F10.
The Dayton is the only one that looks like it will do well in a small sealed box. As I mentioned, PE says F3=30Hz in 1.1 cubic feet.
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A 12db/oct 500Hz (and 6kHz) crossover was used in the Yamaha NS1000.
I don't think it's too far to try 400Hz LR4. This will actually provide better protection from low freq waves than the NS1000 xover.
A 66mm diameter flat wound copper wire strikes me as more robust than what we find in most tweeters, but no way to test without breaking one -- and these domes are just too rare to do that. I guess we could find out in actually use.
Regarding the weight of the Dayton woofer: Surely it's not the moving mass by itself that's critical for transient response, it has to be the combination or ratio of moving mass & motor strength. BL of 15T·m looks, pretty decent, imo. But yeah, I have my doubts about how well this driver will play up into middle-A area.
I don't think it's too far to try 400Hz LR4. This will actually provide better protection from low freq waves than the NS1000 xover.
A 66mm diameter flat wound copper wire strikes me as more robust than what we find in most tweeters, but no way to test without breaking one -- and these domes are just too rare to do that. I guess we could find out in actually use.
Regarding the weight of the Dayton woofer: Surely it's not the moving mass by itself that's critical for transient response, it has to be the combination or ratio of moving mass & motor strength. BL of 15T·m looks, pretty decent, imo. But yeah, I have my doubts about how well this driver will play up into middle-A area.
