Dayton Audio SD215-PR 8" Passive Radiator

Brand:| Model: SD215-PR
The new Dayton Audio Passive Radiators are excellent general-purpose passives suitable for replacement or for new construction.
Part # 
Weight: 1 lbs.  
List Price$22.99
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Buy 4-up$17.25
Part # 295-492
Qty:  EA
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Product Details

Dayton Audio SD215-PR 8" Passive Radiator

The new Dayton Audio Passive Radiators are excellent general-purpose passives suitable for replacement or for new construction. A built-in mass disc offers a good starting point for most designs, and a convenient M5 threaded hole (screw included) allows different types of weights to be added if desired. Cosmetically and mechanically, the passives match the Shielded DVC line of subwoofers, with a poly coated paper cone and medium-roll rubber surround for clean excursion and long life. The possibilities with these passives are endless, from floor standing two-ways to small active/passive subwoofer systems.

Specifications: • Fs: 21 Hz • Vas: 1.40 cu. ft. • Qms: 2 • Cms: 0.75 mm/N • Mms: 0.75 g • Sd: 194 sq. cm. • Xmax: 9 mm • Dimensions: Overall diameter: 8.50", Cutout diameter: 7.09", Depth: 2.28".


Product Specifications
  • Nominal Diameter8"
Dayton Audio SD215-PR 8" Passive Radiator
  • BrandDayton Audio
  • ModelSD215-PR
  • Part Number295-492
  • UPC844632000393
  • Product CategoryPassive Radiators
  • Unit of MeasureEA
  • Product Rating
    (9 Reviews)
  • Weight1 lbs.
  • Case Qty12
  • California Prop 65

    Warning: California residents only. Please note per Proposition 65 that this product may contain chemicals known to the State of California to cause cancer and birth defects or other reproductive harm.

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Dayton Audio SD215-PR 8" Passive Radiator
Dayton Audio SD215-PR 8" Passive Radiator is rated 4.3333 out of 5 by 9.
Rated 4 out of 5 by from Replaced blown Sunfire Super Junior passive radiatorI bought this to replace a blown Sunfire Super Junior passive radiator. It fit the hole perfectly. I believe it, like any speaker, could use some warming up and stretching before criticizing it. In the week I have had it in the enclosure, I believe it has warmed up considerably. I have yet to meter the sub again and I have yet to open the amp on it but my initial observation is saying that I will need to pin the volume back a little. Great price, great value and it does the job!
Date published: 2014-04-01
Rated 4 out of 5 by from Excellent alterative to porting.Bought these to use in a DIY home theatre sub along with an 8" Tangband. I like the sound better than ports. Bass is tight and controlled with no port noise. The option for adding weight to change the resonance is a nice feature and is easier than trying different port lengths for tuning.
Date published: 2014-04-01
Rated 5 out of 5 by from passive-ly speaking.I had a TB 6x9 woofer collecting dust on the shelf, decided to match it with the 8'' passive radaitor in a .33cf box. Unit sounds good.
Date published: 2014-04-01
Rated 5 out of 5 by from oooh! Rad(iator)!I built a triska and love it! Don't ask toooo much as it's just a lil 70 watt 8" but it's pretty rad, I must say!
Date published: 2014-04-01
Rated 4 out of 5 by from Another great findIf you need an 8" PR, these are great for the price. I'm using them with a 6.75" driver in an automotive application and they work great
Date published: 2013-06-29
Rated 4 out of 5 by from good value/qualityMaybe a bit too stiff. Probably will loose up a bit after period of use.I use as passive for my quattro sub.Very tight/well control bass. Need more power than bass reflex design though.
Date published: 2014-04-01

Product Q&A

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If your question requires design or troubleshooting information,
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Dayton Audio SD215-PR 8" Passive Radiator

how do you design a sub box to use a passive radiator?

how do you know what size passive radiator to use?
Asked by: jaredd
Generally, you need twice as much displacement from the PRs as you have from the woofer/subwoofer that is driving them. So, if you have an 8" woofer with 6mm of excursion, then (generally) you'll need at least two 8" PRs with at least 6mm of excursion. If the PRs are any significant amount smaller than that then they will probably bottom out, which will sound bad and possibly destroy the PRs. If they are a bit bigger, that should be ok.However, the above is just a generalization, and to actually build a PR box properly there are many more steps. Generally this is how I do it:1. Choose the woofer/subwoofer I want to use2. Pick a few possible PRs to use. For each PR:a) Enter the woofer/subwoofer's specs and the PR's specs into a speaker design program that supports simulating PR boxes. One such program that is easy to use, is free, and which I use all the time is WinISD Pro (it has to be the "Pro" version. The basic version does not support PR boxes).b) If the program you use is able to calculate an optimal design for the given driver and PRs then great, but WinISD can't do that. So instead I have to manually play around with the parameters. First I usually set the box size to something that is typical of a ported box for the given woofer/subwoofer (because ported boxes are very similar to PR boxes, so the internal volume will be similar). Then I adjust how many PRs I have and the amount of mass on each one, and adjust the box size some more if necessary.c) When configuring the box, there are several parameters to optimize. Obviously, the frequency response should be as flat as possible, like with all boxes. Also, you must make sure that the woofer/subwoofer AND the PRs are within their excursion limits at ALL frequencies (even below 20Hz). When doing this, make sure the power level you are simulating in the program is the maximum power level that you'll likely use the speaker at (most programs set the default simulated power level to 1W or something similar, so you'll have to change this).3. After simulating all the PRs, I figure out which PR works best with the particular woofer and go with it.That should get you off to a good start.
Answered by: eboyer
Date published: 2014-04-01

cut out diameter

What is the cut out diameter for the 295-492 passive radiator? Thanks
Asked by: dsjacr
Most speakers at Parts Express have a "B" dimension listed within their specifications. The cutout required for this passive radiator is 7-1/8".
Answered by: mikevv
Date published: 2011-02-27

Does it come with weights or should I just go to home Depot?

Asked by: buyer
This series of passive radiators features an M5 threaded insert. No hardware is provided to tune the radiator. Customers typically buy an M5 bolt from a hardware store and use washers to add weight.
Answered by: mikevv
Date published: 2013-12-28

i have a 12 inch sub for my home audio system its good but its not getting enough bass for my taste i was wondering if i could add this to the box

if not what can i do to make it better i dont know much about pr so plez explane if the simplest way possible
Asked by: colton puckett
There is no simple answer to this question. When you say, "not enough bass" are you referring to volume or "feel" or to how low the bass notes go? If the overall quality of your bass is what you want and you want to add a little more "feel" or amplitude to the bass, this passive radiator may be just what you need. Don't look for major changes however. Passive radiators can only add a little to what you already have. Whether or not you add a passive radiator, I would also recommend experimenting with speaker placement (try a corner front-facing and then rear-facing) and your crossover frequency (try setting it higher), these can be important factors. Good luck!
Answered by: FlyBoy
Date published: 2013-03-24

this is in regards to my other quistion about mt 12 inch sub

OK what i ment by not enough bass i can fell the bass as much as i would like i would like to have and the box i have is a custom box and its about 2 and a half felt long and 13 inches wide with a mounting depth of about 10 inches these are not exact but give or take a couple inches the sub is 500max and 125 rms i was thinking about getting another 12 inch but i cant fine a cheap one that i get as close on the watts for it and the box is ported idk what it is tuned at i got it from a friend if u know a way to find out let me know
Asked by: colton puckett
If you could post the brand and model of your speaker and the exact measurements of the enclosure (including wood thickness) and the exact size and length of the port, I can probably give you the tuning frequency of your current enclosure.Honestly it doesn't sound like this is the answer to your question though. If what you have isn't giving you enough bass in any way, and you are using a 12" sub the passive isn't likely to really give you any real improvement in that direction.A rule of thumb with passives is to use twice the radiator size as the driver size which means two 12" passives for one 12" subwoofer. Even at that, you are going to "tune" them similarly to a port and your output is more likely to go down in terms of DB as opposed to a properly tuned ported enclosure.Bass amount is relevant to two things. Driver area and power. If you want a lot more bass than you have, your best bet is likely to be to purchase a better sub with a custom enclosure built for the driver and the room and/ or add more power to your setup. Give us some more details and we can probably make some comparisons for you.
Answered by: Musgofasa
Date published: 2013-03-24

this is the box mesurements and sube detials

ok the box use 1.5 cm thick wood i dk what kind the mounting depth it 10.5 inch and the port is 2.5 inch diameter and 4.5 inch long the box is 35.5 inch tall and 14 inch wide and 11 inch in length the sub i am use in the dual ds12 500watt max and 125 watts rms also i add a picture as well as a link to the sub and i know its not for home audio but i am on a relly tight budget
Asked by: colton puckett
Without knowing what kind of amp will be used, or how the system is used, I would suggest a passive radiator of larger excursion and diameter for use with this 12" Dual sub. At least a 12" PR.
Answered by: C from Claypool
Date published: 2012-02-17

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