ST900 Platinum Speaker System

Speaker Size

Rockford Fosgate Motorcycle Speaker SystemKicker Motorcycle Speakers


Looking for the absolute best in a bar mounted bolt-on speaker system? The ST900 Platinum Motorcycle Speaker System by Steel Horse Audio, featuring Rockford Fosgate® amplification and Kicker® speaker technology, is your answer ... with over 900 peak watts of industry leading, distortion free output and pure full range highway sound, nothing comes close!

  • Over 900 watts of CEA-2006 certified peak power for top end, best in class sound at any speed, even with loud pipes 
  • Easy bolt-on installation to the handlebars or highway bars of any Harley, Indian, Honda, Yamaha & More
  • Illuminated handlebar mounted controller for play/pause, volume & tracks
  • Connect to any Bluetooth® enabled device for a wireless audio connection
  • Also connects to any standard headphone jack for universal compatibility
  • Acoustic baffles for added bass response and musical clarity
  • Choose from 4" or 5.25" speakers with a 2-speaker or 4-speaker option
  • Pair with Saddlebag Lid Speakers for the ultimate audio experience
  • All-Weather certified for even the harshest weather conditions
  • True spec-tinned Oxygen-free Copper speaker wire for superior sound and corrosion prevention
  • Made with steel enclosures in a high quality show chrome or satin black finish
  • Premium 8 Gauge Amplifier Wiring Kit with 100% Premium OFC Copper
  • Designed and built in the USA with only the highest quality components
  • Industry leading 5-year warranty on all parts and components




  • Speakers | Channels: 2 or 4
  • Peak Wattage Power: 900W ~ 1050W (CEA-2006 Certified)
  • RMS Total Wattage: 400W ~ 500W (CEA-2006 Certified)
  • RMS Channel Output: 200W x 2 Channels / 100W x 4 Channels
  • Classification:  Full Range Class BR
  • Signal-to-Noise Ratio:  >90dB
  • Total Harmonic Distortion (THD+Noise):  4-Ohm: <1.0%
  • Frequency Response: 20Hz - 20kHz +/-1dB
  • True spec-tinned Oxygen-free Copper wire
  • Amplifier Size: 1.53 x 4.25 x 6.75 (in.) 
  • 4" Speaker/Enclosure Size:  4.75" (Diameter) x 3" (Depth)
  • 5.25" Speaker/Enclosure Size:  5.75" (Diameter) x 3.25" (Depth)




  • Rockford Fosgate® PBR extreme amplifier (We recommend the optional PBR amplifier mount)
  • Illuminated, weatherproof handlebar mount controller with Bluetooth®
  • KS Series Kicker 4-inch (4") or 5.25-inch (5-1/4") speakers in waterproof housings
  • 100% Copper spec speaker and amplifier wiring kit
  • 3.5mm to RCA cable for optional connection to any standard headphone jack
  • Speaker and controller mounting hardware for 1" & 1-1/4" bars included (Other sizes available upon request)
  • Instruction manual with black zip ties

This is for a complete Steel Horse Audio 900W+ Bluetooth Motorcycle Speaker System.  All you need to provide is your mobile audio device.



Ask a Question
  • With the 4 speaker system with two 4" and two 5.25", can both speakers fit on a touring crash bar? The 4" mounted on top, and the 5.25" mounted on bottom?

    This is a popular option and works very well to mount all 4 speakers on the crash bars.

  • If the amplifier installed in the saddlebag, will it be easy to remove the saddlebag, and easily detach the amplifier harness?

    Yes, the amplifier has a quick disconnect harness, making it very easy to just remove the bag and disconnect the amp.

  • With the 4" + 5.25" ( 4 speaker option) is it 2 - 4" and 2 - 5.25" speakers?

    Yes, that option will get you a pair of the 4" and a pair of the 5.25".

  • Can these be heard on the freeway with a full face helmet on?

    Yes, these are desgined to be loud and clear at highway speeds (80+), with no windshield and straight pipes.  Adding a helmet will actually cut down on wind noise and helps improve the sound even. more.

  • How much are the 4 inch speakers by themselves?

    The 4-inch speakers by themselves are available as the Unplugged Edition (STSPKR).  You can find all the different models here:

  • Is there any difference in the 4 inch speakers and the 5.25 speakers?

    The biggest difference between the 4" and the 5.25" will be the bass. The 5.25" has a larger woofer which will push more of those lows for a heavier bass sound. It can also handle a bit more volume, but other than that, the sound is very similar.

  • Will the high end speaker system fit on a 2018 Sportster 1200?

    Our systems are universal mount and are designed to mount to the handlebars or highway bars of any motorcycle, including the 2018 Sportster 1200.  If you take a look at our photo gallery, we have a few Sportsters in there that you can check out.

  • How do these speakers compare to the Kicker PSM3?

    The Kicker PSM3 are an average speaker that are limited because of the 3" size and max wattage.  We use a 4" speaker with over 900 max watts for added bass and volume output in a highway rated motorcyle speaker.

  • Would it be possible to buy ST900 4-speaker set with only 2 speakers as I’m planning to run 6.5” kickers in the lower fairings and 2 speakers from the set on handlebars?

    Yes, this is a popular option.  Just let us know after placing the order and we can include the 4-channel amp instead of the 2-channel.

  • Can I get four speakers, one pair in Chrome and one pair in Black?

    Yes, that is no problem.  Just message us after you place the order and we can take care of it.

  • What gauge are the speaker wires? What gauge are the hot and negative wires?

    16 gauge True spec-tinned Oxygen-free Copper speaker wire and 10 gauge hot/positive (+) and ground/negative (-) wire connections.

  • Ok if you could rate the st900 would you rate this system with the oem harley davidson boom system

    Consindering we get quite a few of the H-D Boom bar mount systems in for the trade-up program, and that I have actually heard them compared to ours, I would say the Boom is about a 5 and we are about a 9 (out of 10).  They easily drown out the Boom speakers... And still remain clear and full range.

  • Can I add a subwoofer to my bike with this amp?

    As long as you get the 4-channel version, you can run Steel Horse Audio speakers with the front 2 channel and a set of subwoofers (lids) with the rear 2 channels.

  • How much louder and better is the sound on the ST900 over the ST600?

    The ST900 speaker system is about 15-20% louder.  They are both fantastic systems and work well for highway riding, even with straight pipes and no windshield.

  • Can you run two of these amps with same Bluetooth controller that comes with it? I want to run one amp for saddlebag speakers and another amp for front speakers!

    The best option would be to do the 4-channel ST600 amplifier and power the Steel Horse Audio speakers with the front channels and the lidspeakers with the rear channels. The results are phenominal...  If you start to add additional amps, it will be too much for the charging system and battery.

  • How many watts does it put out if running it 2 x channels?

    When using 2-channels, Peak wattage is over 1000 watts and RMS wattage is 100 Watts x 2 @ 4-Ohm or 150 Watts x 2 @ 2-Ohm (RMS).

  • Could u please show a really good picture of the amplifier wiring harnesses that come with this?

    You can see a photo of the amplifier wiring harnesses here.  We also include an official Rockford Fosgate wire kit with the proper wiring for power, ground and remote connections.

  • I have a Freewheeler 2016 HD. Will the ST900 4 speakers fit ? Plus will you recommend putting two speakers in the front and two speakers on the back of the motorcycle?

    We have installed the 4 speaker system on numerous Freewheeler bikes.  It is a very nice, clean install.  Most people will go on the handlebar and highway bar, or rear backrest.  There are some photos in our gallery of freewheeler installs here:

  • I have a Yamaha Raider... could a 4 speaker system fit this bike, and can you give me an idea on mounting?

    The ST600X2 (4-speaker system) will fit your Yamaha Raider.  You would mount one set of speakers to the handlebars and the other set to the front down tubes, highway bars or forks.

  • Does this speaker system work on a 2006 Wide Glide Harley Davidson?

    The ST600 is our top end system.  It is universal and compatible with the '06 Wide Glide.  The ST400 and ST200 motorcycle speaker systems are also compatible.

  • Does it fit a Vrod handlebar?

    The ST600 Motorcycle Speaker system will fit on the H-D VRod bars using the included mounting hardware.  We have installed a few of these on VRods.

  • I'm looking at the ST900 4 speaker system, my bike has 6X9 speaker mounting holes in the saddle bag covers. Can you supply or recommend the 6X9's needed to compliment the system.

    We recommend the Kicker PS692 6x9 speakers.  These compliment the ST900 system very well and match the correct wattage and specs.

  • Is there a dedicated on/ off power switch for the soundsystem?

    There is a dedicated on/off power switch on the handlebar remote.  Additionally, there is a signal sensing source, so if you forget to turn it off, it will turn off on its own after 5 minutes, to prevent battery drain.

  • Can the ST900 amp run 6-8 speakers?

    The ST900 amplifier is a 4-channel amp.  You could use it to power more channels by wiring in parallel or series, depending on the speaker specs.

  • What size of windshield bag is needed to house the amp to allow for proper cooling?

    The amplifier measures 1.53 x 4.25 x 6.75 (in.) and can fit in most windshield or tool bags while allowing for proper cooling.  As long as the amp is not wrapped in cotton or other fabric, it will be fine.  For a windshield or toolbags we recommend Hot Leathers as any of these will work and allow proper cooling... Windshield Bags: or Tool bags: (

  • Can the amp fit inside the Can Am compartment or how big is the amp itself

    Yes, it should have no problem fitting the Can-Am compartment.  The amp measures 1.53 x 4.25 x 6.75 (in.).

  • Is there a lot of difference in sound quality between the 400 and 600 series

    The ST600 is about 20% louder then the ST400.  The quality on both is great.

  • Can I run 2 saddle bag speakers with the 4 speakers system and can the speakers be adjusted to mount on handlebars that are 1 inch 1/2?

    The 2-speaker ST600 system will come with the 4-speaker amp, so this is a great option.  Running 2 of our front speakers and then 2 saddlebag lid speakers is a popular option and sounds phenominal.  We offer mounting clamps up to 1-1/2" handlebar size upon request.

  • I've used the Boss handlebar systems that claim 400, 600 and 800 Watts, yet all three of those could barely be heard at 75 mph behind a windscreen.. How much loudness difference is there between boss handlebar systems and your speaker systems?

    Unfortunately Boss (and quite a few others) use inflated peak wattage numbers to advertise their speaker systems, when in reality they push maybe 40 watts of true power.  Our systems only use true wattage ratings for great sound at highway speeds, even with straight pipes and no windshield.  The ST600 in particular is CES-2005 certified for wattage and will even rival many bagger/fairing motorcycle speaker systems.  We back this with a 60-day money back guarantee and 5-year warranty.  As a comparison, even our lowest end 200 watt speaker system (ST200) will drown out any Boss system on the market (we take a lot in for trade).

  • Is the amplifier waterproof for frame mounting or needs to be secured in the one of the saddlebags? If the latter, are sufficient wiring lengths part of the system?

    The amplifier is water-resistant but not waterproof (speakers and control are submersible waterproof).  So while it can get some exposure to water, we recommend going in a bag (saddlebag, fork bag, windshield bag, swing arm back, front down tube bag, etc).  There is 10+ feet of wiring included for easy installation in any location.

  • Are the speakers the same between the ST400 and ST600, just different amps?

    The speakers are different to accommodate the wattage difference between these systems/amplifiers.  The ST400 uses a CS version of Kicker speakers and the ST600 uses a higher wattage KS version.

  • Are there any charging requirements for the ST400 or ST600 system? How many amps of power do these systems draw?

    There are no specific charging requirements.  These will work on any motorcycle or power sports application, even scooters and UTVs.  The ST400 will draw about 15 amps of power and the ST600 about 25 amps.

  • does it have a radio feature?

    It does not have a built in radio, but works with any audio device, with or without Bluetooth.  Most audio devices then offer an FM radio option, whether it is a built in FM radio tuner or an app such as iHeartRadio.

  • If I buy a 2 speaker system and decide later I want 4 speakers, can they be added?

    Yes, you will receive the same 4 channel amplifier with the 2-speaker system and can easily add on 2 additional speakers at any time.

  • Do you get a whole lot more sound from 4 speakers? Being that two of them would attach to mustache bars

    You get an average of 15-20% more sound output with 4 speakers, plus a fuller, more surround sound experience

  • 1st how hard to install? 2nd will they attach to 1 1/2 inch handlebars?

    We design all our systems as self install kits.  They only require mounting and a few wire connections.  Installation can typically be completed in an hour or two. You can see a set of the instructions under the 'Product Specs' tab....  The speakers will attach to any 7/8" to 1-1/2" bar sizes.