Dayton Audio SD215-PR 8" Passive Radiator

Brand:|Model: SD215-PR
The Dayton Audio Passive Radiators are excellent general-purpose passives suitable for replacement or for new construction.
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Part # 295-492

Product Details

Dayton Audio SD215-PR 8" Passive Radiator

The 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: 75 g • Sd: 194 sq. cm. • Xmax: 9 mm • Dimensions: Overall diameter: 8.50", Cutout diameter: 7.09", Depth: 2.28".


Note: Adding mass to the passive radiator will decrease Fs and increase Qms.

Tip: As a general rule the passive radiator(s) should be able to move double the volume of air as the active woofer(s)/subwoofer(s) in the system. For example: A passive radiator system for a 8" woofer/subwoofer that has 9mm of X-max would require 2-8" passive radiators with 9mm of X-max. For single passive radiator systems, it is common to use a passive that is larger than the active woofer(s)/subwoofer(s).

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
    (12 Reviews)
  • Weight1 lbs.
  • 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.

View similar products to the Dayton Audio SD215-PR 8" Passive Radiator
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Dayton Audio SD215-PR 8" Passive Radiator
Dayton Audio SD215-PR 8" Passive Radiator is rated 4.0833 out of 5 by 12.
Rated 1 out of 5 by from Passive is an Understatementthis unit is a joke. Dayton Audio...I'm gone. This is the last DA product I'll ever bet on again.
Date published: 2015-09-30
Rated 5 out of 5 by from Contol The Bass In Reflex Full Range SpeakerI had purchased a pair of Audio Nirvana Super 8 ALNICO full range drivers after being told that they were the "perfect storm" speaker and that they provided the most bass of all the different Audio Nirvana drivers. I built an enclosure to specifications provided by the manufacture and was left with a bass reflex speaker that has fantastic mids and highs but the bass was uncontrolled and left much to be desired. They sat unused for years and then I decided to try putting a passive radiator in the enclosure to see if that would help. Wow, exactly what was needed. The passive radiator provided the control that was missing with just a 3" port. The tight and precise bass is so smooth and real. It truly was the missing piece to this loud speaker.
Date published: 2014-08-22
Rated 4 out of 5 by from Great replacement for Sunfire Tru Jr. SubwooferThe screw holes don't line up with the existing holes, but a few new screws and a drill takes care of all of that. Great replacement for the radiator of a Sunfire Junior Subwoofer. Once the woofer stretches out and gets loose, it works and sounds great.
Date published: 2014-08-06
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: 2013-09-09
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: 2013-05-21
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: 2011-04-19
  • 2015-10-08T06:58CST
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Product Q&A

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Dayton Audio SD215-PR 8" Passive Radiator

Would just one of these 8" passive radiators work paired with a JL-Audio 6W3v3? Or would it require 2? In such a scenario, minimum sealed box volume would be? Would weight need to be added to the PR? How is weight typically added?

Asked by: TheGDog
This will work with one passive. I would recommend a volume of 0.32 cubic feet with 75 grams added to the passive which will tune to 37 Hz and provide an F3 of 37 Hz.
Answered by: MattP
Date published: 2015-09-29

To eliminate port noise on my Energy ESW-8 8-inch powered subwoofer, I'm looking to seal up the reflex port and add one (or two) of these PRs. The sub goes down to about 33-hz. Would this passive radiator fit the bill for what I need?

Asked by: albeau
It could, unfortunately we have no way of modeling anything to help with tuning or how much weight to add. If the active woofer is 8", I would recommend two 8" passives. Adding weight will drop the tuning frequency but you don't want to add more than 75 grams to each of these.
Answered by: MattP
Date published: 2015-09-29

Can you use an 8 inch passive Radiator, with an 15 inch woofer, 6.25 cubic ft. cabinet? it was calling for 2 four inch ports 1 inch long, Can I use the passive instead?

Asked by: jamman69
Please contact our tech support for more help with this question, or 800-338-0531 x1.
Answered by: MattW
Date published: 2015-07-20

Would this PR be a good fit for the Dayton SD215A-88 8" sub in a .35 cu ft box? Or would I be better off leaving the subs sealed? This would be under each front seat in my car for midbass. Transient response is slightly more important than volume

Asked by: Bendy
Yes, that passive radiator will work well with the SD215A-88 in a .35Ft3.
Answered by: MattW
Date published: 2015-04-10

Im building a set of Line-Arrays 7"x72"x 11" internal , with 8- SB Acoustics 5" - SB13PFC25-08 . I was thinking of using 2 x 8" radiators one on each side at the bottom of the case ,is my assumption correct on size of radiator and mounting location ?

Asked by: wildchild
You will actually need eight of those passives in order to maintain a high enough tuning frequency and keep excursion down. Eight passives with no weight added would provide a tuning frequency of about 45 Hz and F3 of 70 Hz. In the volume you have you could also just port the enclosure with two 4" diameter, 5" long ports for the same tuning frequency but an F3 around 50 Hz.
Answered by: MattP
Date published: 2015-03-20

Looking to make a small subwoofer for the garage using this with the Tang Band W6-1139SIF 6.5. Is .33 cubic ft. the ideal size and how much weight would i need to add?

Asked by: MEMFIS
Yes that volume is perfect. I would add 75 grams to the passive which will provide a tuning frequency of 35 Hz and an F3 of 44 Hz.
Answered by: MattP
Date published: 2015-01-19
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