Dayton Audio RSS315HO-4 12" Reference HO Subwoofer 4 Ohm
I was offered this driver for a price I could not pass up. (this has happened a few times already). So now I might as well put it to use.
This sub would support an active, existing, open baffle 3 way. The open baffle sounds great, but does not quite extend deep, plus but I'm not comfortable with the excursion at lower frequencies, so it would be great if I could relieve them a little.
The sub needs to cover up to 70 hz or so only. Strictly music. Not looking for earbleeding spl either, just "enthusiastic" listening. I have a tda7492e board at 36v for amplification available (I could get something else if I need to). Minidsp XO. Ideally, this would be the first of two subs.
The problem of course is size. Smaller is better.... I could hide a 6 ft external vent behind the couch though.
I was offered this driver for a price I could not pass up. (this has happened a few times already). So now I might as well put it to use.
This sub would support an active, existing, open baffle 3 way. The open baffle sounds great, but does not quite extend deep, plus but I'm not comfortable with the excursion at lower frequencies, so it would be great if I could relieve them a little.
The sub needs to cover up to 70 hz or so only. Strictly music. Not looking for earbleeding spl either, just "enthusiastic" listening. I have a tda7492e board at 36v for amplification available (I could get something else if I need to). Minidsp XO. Ideally, this would be the first of two subs.
The problem of course is size. Smaller is better.... I could hide a 6 ft external vent behind the couch though.
If you've got the minidsp you can go really small sealed and eq to taste. If you want to go vented I've had good luck with a 40L inclosure tuned to about 26-28hz or so.
I'm having a hard time getting bassbox to model this driver in a sealed box. It keeps returning an F3 of ~65hz.
A vented box requires a pretty large port, and even though I said I could hide an external port, it is not the most elegant solution.
It seems a pair of passive radiators might work well, but I'm getting a little tired of bassbox crapping out on me all the time (anyone else have stability issues with bassbox 6?).
A vented box requires a pretty large port, and even though I said I could hide an external port, it is not the most elegant solution.
It seems a pair of passive radiators might work well, but I'm getting a little tired of bassbox crapping out on me all the time (anyone else have stability issues with bassbox 6?).
That f3 is extremely close to the sealed box response noted on the Dayton page you yourself linked to in post 1 - why do you therefore think you're having a hard time if it agrees with the manufacturer?
FWIW, any driver with a Qts as low as 0.31 will exhibit this behaviour in a sealed box - the f3 will always be much higher than Fs.
Your options are therefore choose another type of loading, or resort to a Linkwitz Transform type circuit (Analogue & Digital options both available) to allow you to manipulate the final frequency response to what you want. This option does use up a lot of the driver's thermal and dynamic headroom to do it though - ie you're throwing lots more power at it at low frequencies.
Well, probably because I don't really know what I'm doing... 🙂 (Seriously, I'm just starting with this). It's good to see that i'm getting the same magnitude of numbers.
I believe i'm on track with a passive radiator box.
Using two of these : Dayton Audio DS215-PR 8" Designer Series Passive Radiator
With a total mass of 130g each
in a 12.5X12.5X18" (internal) box
should yield an F3 in the low 30's?
I'm not an expert on PR's, but I have seen recommendations to use a ratio of approx 2x the SD of PR to main driver.
That's because with the PR's doing most of the work down at the tuning frequency, they can have substantially higher excursion than the main driver, (at least, I think...). There's even a tip on that Dayton page you liked to saying much the same thing - you did take account of that, right?
Make sure you model the excursion of the PR's at full power, as well as the excursion of the main driver.
That's because with the PR's doing most of the work down at the tuning frequency, they can have substantially higher excursion than the main driver, (at least, I think...). There's even a tip on that Dayton page you liked to saying much the same thing - you did take account of that, right?
Make sure you model the excursion of the PR's at full power, as well as the excursion of the main driver.
Not normally, historically need 1.75-2x driver Sd = 15" at minimum for a 12", so too small for a pair of 10" = dual 12".
That said, this was years ago, so may need more for some of these newer super high Xmax drivers.
GM
That said, this was years ago, so may need more for some of these newer super high Xmax drivers.
GM
Thanks guys,
Learning as i go. Looks like the simplest thing to do is to go with 2 12" PR's with similar XMAX as the driver. The DSA315-PR's seem to model well.
Is there a rule of thumb as to how much weight can safely be added to a PR?
Learning as i go. Looks like the simplest thing to do is to go with 2 12" PR's with similar XMAX as the driver. The DSA315-PR's seem to model well.
Is there a rule of thumb as to how much weight can safely be added to a PR?
Never seen one, though have seen specs for some that either list a weight limit or not to use more than what's provided.
GM
GM
I'm confused. You said you got a good deal on the driver but if you have to buy the passive radiators then it turns out to not be that much of a deal. The driver does not require a very big box ported or sealed.
The f3 you state of the sealed enclosure is about right but with minidsp a little eq and you're good.
The port needed will fit in a 40L box no problem, just use a 4" port and an elbow or two. If it starts chuffing you need more subs.
I'm cheap and I hate the idea of paying for passive radiators.
The f3 you state of the sealed enclosure is about right but with minidsp a little eq and you're good.
The port needed will fit in a 40L box no problem, just use a 4" port and an elbow or two. If it starts chuffing you need more subs.
I'm cheap and I hate the idea of paying for passive radiators.
You're right. A sealed box can be very small, but seems to be ~10dB down at 30hz. It just seems like a lot to make up, but maybe i just need to go ahead and try it.
with the minidsp and enough amplifier this will not be a problem. You may not end up needing as much eq as it first seems. It's best to measure in room and eq to taste.
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