Hi all,
I've been thinking about doing my first small-medium subwoofer build and I'm hoping someone would be kind and patient enough to critique what I've come up with so far. This is a bit long winded as I'm trying to talk my way to a decision.
My project goal is for a -3dB in the mid-30s, with an overall volume less than 2cf. Maximum SPL isn't a priority. I already own a Dayton 100W plate amp that I'll start the project off with, but probably upgrade in the future. I have a budget of $200 or so for drivers/ports/etc, and I'm in Canada so driver selection tends to be a little more limited but Solen.ca is usually my go-to. I mostly played around with the Dayton Audio DCS255, DCS305, RSS(210/265/315)HF, and MX10.
I've already crossed sealed boxes off my list as I know I can't meet my goals without a massive box and/or DSP which I don't have the ability to do right now.
Finalist 1
Driver : Dayton DCS255-4
Box : 1.8cf, tuned to 32 Hz
Port : 4" x 16" round
Total Volume : 2.3 cf (includes port)
Ported seems like the obvious choice so this is my control, but when including the port my box volume tends to get larger than I want. This ones a bit large for me but I think I could make it work. Digs deeper than I need but overall pretty happy.
Finalist 2
Driver : Dayton DCS305-4
Passive Radiator : 1xRSS315-PR
Added Mass : 200g
Total Volume : 1.8cf
I was inspired to look into PRs when I came across the Meniscus Baby Boomer. I tried to match their claimed 30Hz F3 at 1cf but couldn't even get close. This was my best attempt using a single PR, and the PR costs more than the driver which seems a bit silly for me to consider and makes this the most expensive option. I'd also prefer dual PRs for the force cancelling property.
Finalist 3
Driver : Dayton DCS255-4
Passive Radiator : 2xDS315-PR
Added Mass : 200g
Total Volume : 1.3cf
Really happy with how small this is, but a bit of a hump in response. Might increase the box size a bit to try and get rid of it. Cone excursion makes me a touch nervous too but its at such a high power level I don't think it's a realistic issue.
Finalist 4
Driver : Dayton DCS305-4
Passive Radiator : 2xDS315-PR
Added Mass : 300g
Total Volume : 2.0cf
The added mass is right at the limit of what Greg at Dayton Audio said was "safe" but it still makes me a bit nervous. Excursion limits are under control and it digs nice and deep.
My current front runners are 3 and 4, with 3 taking a slight lead due to the smaller size. I might be able to tweak the sizes of both to get excursion and added mass lowered a little bit but I'm curious what I'm forgetting to consider, and what the more experienced individuals would do differently.
I've been thinking about doing my first small-medium subwoofer build and I'm hoping someone would be kind and patient enough to critique what I've come up with so far. This is a bit long winded as I'm trying to talk my way to a decision.
My project goal is for a -3dB in the mid-30s, with an overall volume less than 2cf. Maximum SPL isn't a priority. I already own a Dayton 100W plate amp that I'll start the project off with, but probably upgrade in the future. I have a budget of $200 or so for drivers/ports/etc, and I'm in Canada so driver selection tends to be a little more limited but Solen.ca is usually my go-to. I mostly played around with the Dayton Audio DCS255, DCS305, RSS(210/265/315)HF, and MX10.
I've already crossed sealed boxes off my list as I know I can't meet my goals without a massive box and/or DSP which I don't have the ability to do right now.
Finalist 1
Driver : Dayton DCS255-4
Box : 1.8cf, tuned to 32 Hz
Port : 4" x 16" round
Total Volume : 2.3 cf (includes port)
Ported seems like the obvious choice so this is my control, but when including the port my box volume tends to get larger than I want. This ones a bit large for me but I think I could make it work. Digs deeper than I need but overall pretty happy.
Finalist 2
Driver : Dayton DCS305-4
Passive Radiator : 1xRSS315-PR
Added Mass : 200g
Total Volume : 1.8cf
I was inspired to look into PRs when I came across the Meniscus Baby Boomer. I tried to match their claimed 30Hz F3 at 1cf but couldn't even get close. This was my best attempt using a single PR, and the PR costs more than the driver which seems a bit silly for me to consider and makes this the most expensive option. I'd also prefer dual PRs for the force cancelling property.
Finalist 3
Driver : Dayton DCS255-4
Passive Radiator : 2xDS315-PR
Added Mass : 200g
Total Volume : 1.3cf
Really happy with how small this is, but a bit of a hump in response. Might increase the box size a bit to try and get rid of it. Cone excursion makes me a touch nervous too but its at such a high power level I don't think it's a realistic issue.
Finalist 4
Driver : Dayton DCS305-4
Passive Radiator : 2xDS315-PR
Added Mass : 300g
Total Volume : 2.0cf
The added mass is right at the limit of what Greg at Dayton Audio said was "safe" but it still makes me a bit nervous. Excursion limits are under control and it digs nice and deep.
My current front runners are 3 and 4, with 3 taking a slight lead due to the smaller size. I might be able to tweak the sizes of both to get excursion and added mass lowered a little bit but I'm curious what I'm forgetting to consider, and what the more experienced individuals would do differently.
No 2 seems the best basic idea imo. Volume is quite low and response perfekt for music.
Keep an eye on the x-max of the PR, as it has to match the active woofer. So fit two "Dayton Audio DS315-PR 12" Designer Series Passive Radiator" and recalculate.
Two PR is not the best idea, better use one larger PR, a 15" is usually fine for a 12" woofer. Not many 15" PR´s around...
Please do not expect much advantages of two PR´s cancelling out each others impulse. it is more a theoretical advantage, sound wise not noticeable. Two PR´s means 2 times the losses of the suspension. A PR is a nice alternative, but if I have to save on the driver to use them, I will use a conventional vent any time. I think you overestimate it´s advantage.
Maybe consider to use one of the new "Dayton Audio MX12-22 12" Max-X High Excursion DVC Subwoofer 2 Ohms Per Coil" with a simple vent instead of a PR. Budget is the same, result much better. The design is at least 25 years newer...
You can upgrade it with a DSP and a larger amp in the future. The DCS305-4 is finished with your plate amp.
Maybe simulate a box with the MX-12? Do not go to small on volume. 50-70 litres (inside) should be fine.
Imo the DSP is the tool to use on hardly any Subwoofer, because the sub and the room form a system with very varying parameters. Only the DSP can make room and sub the most perfect match. less then 100$ well spent.
Keep an eye on the x-max of the PR, as it has to match the active woofer. So fit two "Dayton Audio DS315-PR 12" Designer Series Passive Radiator" and recalculate.
Two PR is not the best idea, better use one larger PR, a 15" is usually fine for a 12" woofer. Not many 15" PR´s around...
Please do not expect much advantages of two PR´s cancelling out each others impulse. it is more a theoretical advantage, sound wise not noticeable. Two PR´s means 2 times the losses of the suspension. A PR is a nice alternative, but if I have to save on the driver to use them, I will use a conventional vent any time. I think you overestimate it´s advantage.
Maybe consider to use one of the new "Dayton Audio MX12-22 12" Max-X High Excursion DVC Subwoofer 2 Ohms Per Coil" with a simple vent instead of a PR. Budget is the same, result much better. The design is at least 25 years newer...
You can upgrade it with a DSP and a larger amp in the future. The DCS305-4 is finished with your plate amp.
Maybe simulate a box with the MX-12? Do not go to small on volume. 50-70 litres (inside) should be fine.
Imo the DSP is the tool to use on hardly any Subwoofer, because the sub and the room form a system with very varying parameters. Only the DSP can make room and sub the most perfect match. less then 100$ well spent.
Thanks for your feedback. The main different between 2 and 4 was swapping the RSS315- PR for dual DS315-PRs. Since the RSS315-PR has double the xmax of the DS315-PR (26mm vs 13mm) AND it's stiffer (0.22mm/D vs 0.5mm/N) it never comes close to its xmax at the power limit of the driver.
Yeah there is no 15" PR in the DS series, so that's why I had to jump to the much much much more expensive RSS. I think you're right about trading the PRs for a better driver.
When I started down this road the next step up from the DCS series was the RSS and UM series. The MX is so new there isn't much information about them yet, so I'm not sure what would make it a better or worse sub for music.
I didn't spend too much time on it yet but I did an MX12 in a 50 litre box, and ended up with a 4"x18" vent which seems reasonable. Assuming I added it into WinISD correctly anyway.