Dayton Audio ST305-8 12" Series II Woofer

Brand:| Model: ST305-8
The new generation of Dayton Audio Heavy Duty woofers features natural sounding paper cones that are chemically treated for extra durability and long life. The ST305-8 12" Series II woofer is suitable for pro or home audio subwoofer use.
  • Natural sounding paper cones that are chemically treated for extra durability and long life
  • Consists of a rubber surround and large flat spider for superior damping
  • Feature a large magnet structure
  • Made in USA
Part # 
Weight: 15.33 lbs.  
List Price$129.99
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Your Price
Buy 4-up$90.06
Part # 295-120
Qty:  EA
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Product Details

Dayton Audio ST305-8 12" Series II Woofer

The Dayton Audio ST305-8 Series II heavy duty 12" woofers feature a large magnet structure, vented pole piece, bumped backplate, and large voice coil. This combination provides excellent power handling capability, high efficiency, and very low distortion. The ST305-8 speaker's suspension system consists of a rubber surround and large flat spider for superior damping characteristics and outstanding transient response. Made in the USA.

Product Specifications
  • Nominal Diameter12"
  • Power Handling (RMS)275 Watts
  • Power Handling (max)550 Watts
  • Impedance8 ohms
  • Frequency Response25 to 2,000 Hz
  • Sensitivity92 dB 1W/1m
  • Voice Coil Diameter2.5"
  • Magnet Weight56 oz.
Thiele-Small Parameters
  • Resonant Frequency (Fs)29.6 Hz
  • DC Resistance (Re)6 ohms
  • Voice Coil Inductance (Le)3.07 mH
  • Mechanical Q (Qms)10.55
  • Electromagnetic Q (Qes)0.36
  • Total Q (Qts)0.35
  • Compliance Equivalent Volume (Vas)4.52 ft.³
  • Mechanical Compliance of Suspension (Cms)0.36 mm/N
  • BL Product (BL)15.92 Tm
  • Diaphragm Mass Inc. Airload (Mms)81.33g
  • Maximum Linear Excursion (Xmax)8 mm
  • Surface Area of Cone (Sd)506.7 cm²
Materials of Construction
  • Cone MaterialCoated Paper
  • Surround MaterialRubber
  • Voice Coil Wire MaterialCopper
  • Voice Coil FormerKapton® / Polyimide
  • Basket / Frame MaterialSteel
  • Magnet MaterialFerrite
Mounting Information
  • Overall Outside Diameter12.03"
  • Baffle Cutout Diameter10.95"
  • Depth6.25"
  • Bolt Circle Diameter11.59"
  • # Mounting Holes8
Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion)
  • Sealed Volume1 ft.³
  • Sealed F368 Hz
  • Vented Volume2.52 ft.³
  • Vented F341 Hz
Dayton Audio ST305-8 12" Series II Woofer
  • BrandDayton Audio
  • ModelST305-8
  • Part Number295-120
  • UPC844632000041
  • Product CategoryWoofers
  • Unit of MeasureEA
  • Product Rating
    (42 Reviews)
  • Weight15.33 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.

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Dayton Audio ST305-8 12" Series II Woofer
Dayton Audio ST305-8 12" Series II Woofer is rated 4.4048 out of 5 by 42.
Rated 5 out of 5 by from Very Impressed!I've replaced 2 blown woofers in my satellite speakers,when I first powered these they sounded excellent I thought and was so happy,that was almost 5 yrs ago being powered bya a crown xls 802 and still sound as good as they did the day I bought them,Thanks parts express..ps my order came fast packing was excellent except for 1 woofer was bad,parts express no question asked replaced the bad one,kudo's parts express and have bought a 80hz low pass filter from them also,my 18 inch sub sounds tight!..Thanks...
Date published: 2015-02-08
Rated 5 out of 5 by from Great sounding speakerPlays awesome, would recommend this to my friends, great to play outdoors on my deck.
Date published: 2014-07-01
Rated 4 out of 5 by from Decent woofer for the money.I bought these woofers to replace the ones in my home built 3-way speakers built in the 90s. One of the original Nippon 12" woofers was bad (voice coil scuffing). So I used these Dayton ST305-8 as replacements. They have plenty of bass and handle plenty of power as I am powering them with my vintage Adcom GFA-1amplifier. They do have a slightly different response than my old Nippons (a little peaky) but overall I am satisfied.
Date published: 2014-05-08
Rated 5 out of 5 by from So Helpful!When a woofer in my very expensive Genelec 1037a speakers failed because the form surrounding it didn't like the humidity here in Hawaii I wasn't sure where to turn. The Genelec factory had no replacement parts and no suggestions. Parts Express discussed the specs with me and these woofers have done a terrific job getting my Gelelec's back into my recording studio. Thanks!
Date published: 2014-04-09
Rated 5 out of 5 by from JBL 126A replacementI stumbled across a set of JBL Jubal L65 speakers a couple weeks ago. Unfortunately the original woofers were replaced with pyle 12" woofers. I started the search for replacements without much luck and the only source was that auction site. The pricing too for original drivers was crazy. i ended up calling PE for a recommendation and ended up with a pair of the series 2 woofers. They were a drop in and after hooking them up was really surprised at how well they fit with the driver arrangement.No complaints as of yet and the original woofer was crossed at 1000hz. well bult and made in america to boot! They are not yet fully broken in and given some more listening time should sound even better.
Date published: 2014-04-01
Rated 5 out of 5 by from Great Woofer for the money!!Bought two of these to replace a couple of dry rotted woofers I had in a set of 30 year old speakers that I bought with a stereo stand system. Was not expected too much from these floor cabinets even after the replacement; they were not $500 speakers in the first place. But WOW, these new woofers made the speakers sound like a million bucks!! Very pleased. Nice deep bass and evenly matched. Good value for the price.
Date published: 2014-01-30
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Product Q&A

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Dayton Audio ST305-8 12" Series II Woofer

How would these work in a nxg 400 watt sub that has nothing but trouble with speakers.Meaning the original lasted 2 months.

Asked by: Dean22

These drivers are the perfect match for a project I am drafting. However the gasket looking material on the frame doesn't suit me. Is this material relatively easy to remove? 

Asked by: jparmeley91
The gasket on this woofer is a laminated cardboard/paper type and can be relatively easy to remove if this is something you would like to do. Be careful not to cut the surround.
Answered by: MattP
Date published: 2015-03-02

Can these speakers run off a 4 ohm load in an 8 load cabinet powered from drown xls 802 amp ?

Asked by: Frankie 8
Please contact our tech support for more help with this question, tech@parts-express.com or 800-338-0531 x1.
Answered by: MattP
Date published: 2015-02-11

Is one cu.ft. really the best sealed cabinet size for one of these? How would sound be affected by increasing cabinet size by 50% to one and a half cu.ft. This would be for music and h/t use. Music being most important. How can I contact mainland?  

Asked by: BW28
Increasing the volume to 1.5 cubic feet will drop the Qtc to .585 and slightly lower F3 to 69 Hz. These will really work best in a ported design if you want decent bass from them. A sealed box will only have useable output down to about 40-45 Hz.
Answered by: MattP
Date published: 2015-01-05

i have a 3.1cft tower im rebuilding what size port would i want to play around 30hz

Asked by: planarmagnetic
I would recommend a 4" diameter, 8" long port for a tuning frequency of 30 Hz.
Answered by: MattP
Date published: 2014-12-31

I have an older pair of cerwin/vega r-211s,will these 12" daytons st305-8series ll sound as good ?I have a twin powered harmon /kardon 750 amp to drive them

Asked by: d nick
The Series II woofers are and have been very popular replacements for Cerwin Vega speakers for many years and are usually what I recommend for this type of application. I cannot directly comment on the sound but they have been very well received from our customers.
Answered by: MattP
Date published: 2014-12-11
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