Dayton Audio ST385-8 15" Series II Woofer

Brand:|Model: ST385-8
The new generation of Dayton Audio Heavy Duty woofers features natural sounding paper cones that are chemically treated for extra durability and long life. Suitable for pro sound or home audio subwoofer use.
In Stock
List Price$180.99
You Save28%
Your Price
Buy 4+$123.08
Part # 295-130
  • Natural sounding paper cones that are chemically treated for extra durability and long life
  • Unique suspension system
  • Suitable for pro sound or home audio subwoofer use
  • Made in USA

Product Details

Dayton Audio ST385-8 15" Series II Woofer

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 combination of a heavy magnet structure, vented pole piece, bumped backplate, and large voice coil provides excellent power handling capability with high efficiency and very low distortion. Unique 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 Diameter15"
  • Power Handling (RMS)300 Watts
  • Power Handling (max)600 Watts
  • Impedance8 ohms
  • Frequency Response20 to 1,000 Hz
  • Sensitivity91.2 dB 2.83V/1m
  • Voice Coil Diameter2.51"
  • Magnet Weight90 oz.
Thiele-Small Parameters
  • Resonant Frequency (Fs)15.5 Hz
  • DC Resistance (Re)6.4 ohms
  • Voice Coil Inductance (Le)5.37 mH
  • Mechanical Q (Qms)8.3
  • Electromagnetic Q (Qes)0.29
  • Total Q (Qts)0.28
  • Compliance Equivalent Volume (Vas)18.46 ft.³
  • Mechanical Compliance of Suspension (Cms)0.53 mm/N
  • BL Product (BL)20.7 Tm
  • Diaphragm Mass Inc. Airload (Mms)200g
  • Maximum Linear Excursion (Xmax)7.9 mm
  • Surface Area of Cone (Sd)850.1 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 Diameter15.15"
  • Baffle Cutout Diameter13.77"
  • Depth6.06"
  • Bolt Circle Diameter14.56"
  • # Mounting Holes8
Optimum Cabinet Size (determined using BassBox 6 Pro High Fidelity suggestion)
  • Sealed Volume1.67 ft.³
  • Sealed F348 Hz
  • Vented Volume4.27 ft.³
  • Vented F329 Hz
Dayton Audio ST385-8 15" Series II Woofer
  • BrandDayton Audio
  • ModelST385-8
  • Part Number295-130
  • UPC844632000058
  • Product CategoryWoofers
  • Unit of MeasureEA
  • Product Rating
    (31 Reviews)
  • Weight20 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 ST385-8 15" Series II Woofer
in the Woofers product category.


Dayton Audio ST385-8 15" Series II Woofer
Dayton Audio ST385-8 15" Series II Woofer is rated 4.6129 out of 5 by 31.
Rated 5 out of 5 by from 3-Way Tube Design Full RangeMy first speaker build - "crazy engineer gets idea and hands dirty" - I used these Daytons as woofers in a pair of three-way speakers I built using 24"sonotubes for cabinets in a ported enclosure design. With simple design via the stated parameters, they effortlessly provide clean response down to 20Hz. Not booming bass, just full low-frequency response. Amazing what speakers with this range of response sound like. "Unhurried" bass response; not pressured, not loud; just full rage. They can really fill a big room with sound. I first tested them outside in a 2-acre plot. Just great in large spaces.Please excuse the "trash can" stands and lack of paint in the pictures.I plan to use these woofers in similar enclosures as powered subs.
Date published: 2011-07-18
Rated 5 out of 5 by from smooth and lowbuilt a 19 HZ transmission line sub.It's on casters.... Line length is 15 feet.Hits pretty solid down to 22-24 HZ.Very efficient in this cabinet.Serious bass at 300 watts...Well worth the extra money over other 15's....
Date published: 2011-01-17
Rated 5 out of 5 by from Two of These Perform Well in a 558 Seat TheaterI built two speakers using two of these along with a Goldwood 6 1/2" OEM woofer as the mid, and a Dayton Audio Silk Dome tweeter; all running with a Dayton Audio 5,000 hz 3-way crossover. I built these speakers for my school's theater and these sound awesome! The theater has come alive! Everything sounds better, the piano sounds like someone is actually playing the piano on stage! Vocals sound much better, more natural sounding.The school's theater used to use a pair of JBL JRX115's and sadly, my speakers sound better. One JBL JRX115 cost about 339, while one of my speakers cost 328 to build...The cabinets I built are sealed, which I think sounds better and tightens up the bass. Overall I love this woofer, this is absolutely the best woofer I've ever purchased. Very loud too!
Date published: 2010-03-28
Rated 5 out of 5 by from Wow!Drop in replacement for my Pioneer CS-D9900 four way speakers. Perfect fit and nice increase in performance. Now I'm thinking of updating the mid ranges and tweeters.
Date published: 2009-12-22
Rated 4 out of 5 by from Very powerful outputIt has very strong and steady output with great control. Very, very punchy lows. It takes gobs of power (over 400 watts from Adcom 550 amps!) hour after hour with no problems.
Date published: 2009-11-19
Rated 5 out of 5 by from Outstanding Woofer ReplacementI used it to repalce the woofer that blew out in an 18 year old American Acoustics D8550E 3-way speaker. Dropped right in and sounded fantastic. Highly recommend it as a replacement woofer.
Date published: 2009-07-10
Rated 5 out of 5 by from EXCELLENT WOOFER REPLACEMENTI recently purchased a pair of these Dayton ST385-8 15" Series II Woofers to replace my 18 year old Optimus Mach III (Realistic) due to surround rot out. I didn't want to purchase a new complete set of speakers because I liked the way these speakers looked so my other option was to replace the woofers. The sound is EXCELLENT and the quality of the woofer looks much better than the Mach III. The only thing I had to do was to enlarge the cut-out by 1/8 of an inch which was no problem. I'm using a YAMAHA receiver to drive these speakers. I would recommend these woofers and I also like is the 5 year warranty.
Date published: 2009-03-30
Rated 5 out of 5 by from Good speaker.I used it to replace an Electro Voice Force 15 with an open voice coil. Could not obtain another Force 15.
Date published: 2009-03-23
Rated 5 out of 5 by from awesome frequency responseI utilized these 15's, along with Dayton 5 1/4" aluminum cone woofers, bi-radial horn tweeters, and home made crossovers at 400 hz. and 4k hz., as my front "old school 80's type" speakers. Speakers are in a little over 4 cu. ft. box, tuned to 20 hz.I had used Realistic Mach II speakers, and thought they were really great. But I realize how much I was missing in the range down to 20 hz. and below. It was if another octave lower was finally present. The difference was amazing. The important thing is not the "thump" so much, as to hear and feel the bass vibrations that even go below audible range.
Date published: 2009-02-13
Rated 5 out of 5 by from Couldn't Believe What I've Been Missing!I replaced some 20 year old Pyle Drivers with these and I couldn't believe my ears. Better bass and overall response for my stereo system. Special Thanks to your sales department and my sales guy! KUDOS for your recommendation of these replacement speakers...they are wonderful!
Date published: 2008-12-11
Rated 5 out of 5 by from Couldn't Believe What I've Been Missing!I replaced some 20 year old Pyle Drivers with these and I couldn't believe my ears. Better bass and overall response for my stereo system. Special Thanks to your sales department and my sales guy! KUDOS for your recommendation of these replacement speakers...they are wonderful!
Date published: 2008-12-10
Rated 5 out of 5 by from Excellent Replacement SpeakerReplaced Peavy speakers that were blown out with the Dayton ST385-8 15" series II woofers. The sound has richer tones then the old Peavys. Very satisfied. Recommend highly.
Date published: 2008-12-10
Rated 5 out of 5 by from Rock The BlockThese 15" mad dogs thump like nobody's business. I got them as the crown jewels of my homemade system only to realize that they need 5-9 cubic feet of cabinet space to breathe. I gutted my wife's entertainment center (I'm in the doghouse now) and discovered that I'd better port them or watch the entire $1,000 cabinet explode (Before I ported them, I held my hand up to a crack and the air pouring through it was like the business end of an air conditioner at full blast). Thanks to vault-cracking drillbits and the holes they create, that entertainment center is now a pair of towers the size of matching phone booths. I have since purchased 50-watt L-Pads to balance them against my tweeters and midrange domes (which I turned off so I could get the right amount of "thump" before rounding out the mix). I also took advantage of those $17 buyouts on cheap 15" woofers so I could couple each of the Dayton IIs with a baby brother acting almost as passive radiators to these behemoths with 90-ounce magnets. You can pay more than $99/speaker for a top-shelf woofer, but I don't know why you should. With these godzillas, I don't need subwoofers. My house rocks so completely that I have no idea how far these mothers will go. I'm afraid to find out. I just know that I've got all the bass I will ever need for my system. How many people can say that?
Date published: 2008-07-22
Rated 5 out of 5 by from awsome subOrdered these after talking to Eric in the tech dept. I was oking at some other subs but he said i would not be pleased with them they were like $300 a peace i have had these for around 2 weeks and am very pleased with them. I will defenitly be using Parts-Express again, and i would like to give a huge thanks to Eric. Thanks for the help and saving me $400.
Date published: 2008-07-01
Rated 5 out of 5 by from REAL BassRich, smooth, deep, wall-shaking bass without detectable distortion, these really bring out the low frequencies. I am using them in 4 cu ft sealed, acoustic suspension enclosures, for the 20 Hz to 800 Hz range. These are my fourth make/model in a series of ever-improving woofer trials. Time to stop experimenting. The sound must be experienced to be believed.
Date published: 2008-05-25
Rated 4 out of 5 by from Very nice woofer!I bought 4 of these to replace the 4 woofers in a pair of dual 15" Cerwin Vega speakers (PSX-253). The bass hits harder and goes deeper than the old woofers. I am very pleased and would definately buy Dayton woofers for any other replacement. Also, partsexpress has the fastest delivery ever! Just 2 days! Very good selection as well!
Date published: 2008-05-06
Rated 5 out of 5 by from Great speaker for a good priceI recently bought the dayton ST385-8 15" Series II Woofer, to replace some old school 15" fishers. WOW what a huge difference. There is some much bass now i dont even need my subwoofer.
Date published: 2008-04-18
Rated 4 out of 5 by from Very Good ValueI installed this in a 4.8 cubic foot enclosure with the 500 Watt BASH Amplifier and it sounds incredible. I never knew I was missing so much of my lower frequencies, even with other subs. An excellent product for a very reasonable price.
Date published: 2008-02-19
Rated 5 out of 5 by from best woofer i've heardAmazing bass response. They are better than any subwoofer I've heard.
Date published: 2008-02-02
Rated 4 out of 5 by from Has the right elements but....I used a pair of Dayton ST385-8 15" series 2 woofers in an all-out rebuild to replace some 15" drivers suffering edge rot. They sound just spectacular delivering unreal lows. In a cabinet tuned to 20Hz this can be a borderline emotional experience at high sound pressure levels. However my concern is craftsmanship. I was happy to see they are made in the USA but the fit and finish was a bit of a disappointment. Case and point: The surround appears off center with the gap between the speaker face mounting gasket and the edge of the surround varying between 1/16" and almost 1/8" of an inch. The surround also seems cut thin in places and, quite frankly, I think should be wider where it meets the speaker cone. The dustcap appears just slightly out of round with the mounting edges that meet the speaker cone. Upon unpacking the speaker I noticed the surround mounting gasket would easily become delaminated and thus would reccomend mounting the entire speaker behind the driver board. Otherwise it seems fairly solid: Rear vented pole piece, fairly large magnet, thick voice coil feed wires. Yes they REALLY DO weigh about twenty pounds most being magnet and pole pieces. Clean up the craftsmanship and I think it would be that much better a product. For the price, however, it's steak performance at hamburger prices.
Date published: 2007-11-10
Rated 4 out of 5 by from nice valueThis replaced a 1969 Jensen guitar 15" woofer in a 3 way bass reflex cabinet. The other surviving Jensen has a more natural sound than does this Dayton. The Dayton has a huge magnet and big surround and is a bit boomie on the lows. It should last forever. well constructed.
Date published: 2007-10-12
Rated 5 out of 5 by from More boom for the buckNice clean powerful bass at a very reasonable price. Free shipping promo was great since these puppies weighed 20lbs a piece. They were a replacement for some home theater front speakers I built 15 years ago.
Date published: 2007-09-12
Rated 4 out of 5 by from Accurate low end base responseI purchased a pair of Dayton ST385-8 15 Series II Woofers to be mounted in my homebuilt subwoofer cabinets. Each cabinet is 8 cubic feet (ft3). The speakers are driven with a Hafler 500 power amp via a active low-pass filter. The base response is good down to 30 hz. I am very pleased with this model from Dayton and would recommend it for woofer/subwoofer applications.
Date published: 2007-08-23
Rated 5 out of 5 by from Awesome deep bassI used these in a 3 way system tuned to 20 Hz. The enclosure is a bit too small (a little over 4 cu.ft.) for this speaker, but the depth of bass has to be heard to be belived. I can attest to bass going below the region of hearing, and into feeling. I am not talking about overpowering "thump-thump" one hears from cars, but true deep bass - the final octave between 20 and 40 hz.
Date published: 2007-06-06
Rated 5 out of 5 by from Excellent performance in digital organ subwooferI have two designs for use with a digital organ subwoofer (pedal stops from 32 Hz down to 16 Hz) using the Dayton 295-130. When performance requires fundamental down below 30 Hz, this is the only way I know to provide that acoustic power realistically at a reasonable cost.
Date published: 2007-06-03
  • 2015-11-25T06:31CST
  • bvseo_cps, prod_bvrr, vn_cps_3.1.6
  • cp_2, bvpage2n
  • co_hasreviews, tv_0, tr_31
  • loc_en_US, sid_295-130, PRD, sort_mostRecent
  • clientName_PartsExpressInternational

Product Q&A

Get your questions answered from other customers
who own this product or have experience with it.
If your question requires design or troubleshooting information,
please email  for a prompt reply.
Dayton Audio ST385-8 15" Series II Woofer

Witch 15" woofers will fit the PA knock-down trapezoid speaker cabinet part # 245-326, and what is the top 3 woofers that fit.

Asked by: sibercat
There are many many options that will work in that enclosure. The top three can only be determined by your specific application requirements.
Answered by: MattP
Date published: 2014-01-20

if I were to put this driver in a 10 qubic ft sealed box what would be my low freq cut off point. my free online calculator suggests 41 hrtz for 2.5

cu.ft the problem is it doesn't allow input for different box sizes. 41 isn't bad for that sized box but I wouldn't mind at all buildinga bigger box if I could get down in the 20's of hertzes.
Asked by: spunky
In a sealed box, I don't see a lot of changes in the F3 or 3 db down point. The main difference in the larger cabinet is the rolloff slope. The 2.5 cubic foot box is 15 db down at 20 Hz and the 10 cubic foot box is 9 db down at the same frequency. The cone is also not controlled as well in the larger box.
Answered by: Chrisf
Date published: 2012-11-27

I have a prebuilt box that is a little over 4 cubic feet and has 2 3 inch ports, each about 4 inches long. For this woofer, what adjustment would I ne

Asked by: denzee300
This woofer works very well in 4 cubic feet vented, you will just need to extend the port length to about 12" for a lower tuning frequency of 25 Hz.
Answered by: MattP
Date published: 2012-11-16

whats the recommended ported enclosure for it

Asked by: dwal
Most manufacturers DO post a "recommended" enclosure, even though they are or should be fully aware that you cannot have such a thing that works with all different size rooms, seating positions, input power levels, response requirements, etc. The location of the enclosure in relation to the room walls/corners, as well as in relation to the listeners position, is just as important as the location of the port and location of the subwoofer cone ON the enclosure. If the room has hardwood floors, there is a difference in how the enclosure would be designed versus a thick-pile carpet. I recommend you, and everyone else who asks this type of question, to search the internet for acoustic engineering services. A seriously qualified engineer should be able to design exactly what is needed to accomplish your specific goals. They will charge for their service. But, you would not buy a 500HP motor for your camaro all to throw a cheesy transmission on it would you? It's all about how the entire package works together as a whole. Manufacturer blanket recommendations can guarantee nothing in terms of performance/response or "what you'll hear".Best regards
Answered by: ThaiBoxing101
Date published: 2014-12-14

What port size[s] would I need for a 6.5 cu ft box. please?

I'm hoping to hear my pipe organ records as they should be!
Asked by: jackomancy
In your 6.5ft³ enclosure, you'd want two 3" ports about 11" long each. This will tune your box to around 21Hz, and provide an F3 frequency of 23Hz. In this configuration, the ST385 should handle at least 200 watts before running into any excursion problems.
Answered by: RussR
Date published: 2012-07-18

what port diameter and length would work in a 3 cubic foot box?

My Dayton series II 15" woofers are in a sealed box of 3 cubic feet. I know a vented box should ideally be much bigger to acheive optimal depth. However, I would like to increase the depth of the bass as much as I can within the current box. What do you recommend as far as port length and diameter? The woofer is in a three way passive system handling the frequencies from 312Hz on down as low as we can get it to go.
Asked by: cfinchrist
In your 3.0ft³ enclosure, I would suggest two 3" ports, each about 24" in length. This will put your F3 frequency down to approximately 32-33Hz.
Answered by: RussR
Date published: 2012-09-02
  • 2015-11-25T07:06CST
  • bvseo_cps, prod_bvqa, vn_cps_3.1.6
  • cp_2, bvpage2n
  • co_hasquestionsanswers, tq_12
  • loc_en_US, sid_295-130, PRD, sort_recentQuestionsFirst
  • clientName_PartsExpressInternational

Recently Viewed Products

Get Deals
emailed to you every week.

Be the first to hear about new and exciting products,special pricing and incredible deals!

See This Week's "GET DEALS" Email
Get Sales Flyer
Parts Express
725 Pleasant Valley Dr.Springboro,OH 45066USA

© 1986-2015 Parts Express, All Rights Reserved

Live Chat Software