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SurroundTraxx DSP-80
Multi-Train Sound System for DCC

Ready for the full surround sound experience without breaking the bank? This sound system has been designed with multiple trains in mind. SurroundTraxx gives you the realism of high-fidelity sound moving with the train as it travels about the layout, without installing speakers onboard the engine.

While supplies last, the Manufacturer’s Suggested Retail Price for SurroundTraxx is now $475.95, a $150 reduction from the previous MSRP of $628.95.

SurroundTraxx works with a multiplicity of audio speakers that are strategically placed in hidden locations around the layout. Using the latest digital signal processing (DSP) technology and advanced block detection techniques, SurroundTraxx faithfully reproduces the sounds made by each train on the layout and directs the sound to the speaker closest to the train's location. As a train moves along its route, SurroundTraxx makes continuous adjustments to the sound level of each speaker so that the sound appears to follow the train around the layout.

SurroundTraxx does not simply switch the sound from speaker to speaker. It uses an intelligent cross-fade algorithm that factors in train speed, direction, and distance between speakers. The sound makes a smooth transition as your train travels from one sound zone to the next without abrupt pops or thumps.

  • DCC surround-sound system for your layout
  • Suitable for all scales -- N through G!
  • Sounds interact and “move” with your trains; no onboard speakers are necessary
  • Use with any 8-ohm speaker (or subwoofer for lower frequencies)
  • Six sound channels support six different “sound zones” on your layout
  • Simultaneous sound operations for up to six trains to be dispatched at once
  • Memory storage for up to 99 locomotive profiles
  • An extensive sound library to closely match all popular steam and diesel prototypes
  • Ambient effects such as echo and reverb

How SurroundTraxx Works

SurroundTraxx stores a roster of locomotive sound settings in a database called the Roundhouse. This is an extensive library that you can set up and adjust to match your model's prototype or to sound like your favorite horn or whistle, prime mover, or exhaust chuff. Each engine can have a unique sound profile!

Once you have entered your locomotive roster into the Roundhouse, you can use the internal “dispatcher,” which allows up to six trains to operate simultaneously. SurroundTraxx can be set up to pick the first six locomotives detected, or you can assign these slots to the locomotives of your choice (perfect to make sure your favorite engine never goes silent!). These locomotive “slots” used by the dispatcher are called Auto Dispatch (AD) slots.

After the trains have been dispatched, the block detector will identify the trains' locations, the speed they are traveling, and the point where they will cross into new blocks. SurroundTraxx uses this information to move the appropriate sounds to the corresponding sound channel (six are available) on the SurroundTraxx unit. SurroundTraxx uses an intelligent cross-fade algorithm that factors in train speed, direction, and distance between speakers. This reproduces the sound in such a way that it appears as though it is being emitted directly from the train rather than the speakers on the layout.

The multiple trains running on the layout can all be in the same area or spread throughout the layout. SurroundTraxx will still dispatch and reproduce their respective sounds in full audio richness. It truly is a complete layout sound system with multiple trains and operating sessions in mind!

Note: If using single-channel mode (default), the sound will feed through all six channels at once and does not follow the train. In order to set up the other modes of operation, you must use Digitrax® transponding block detection on your layout.

Included with SurroundTraxx:

  • SurroundTraxx system
  • 5V power supply
  • Network cable
  • Speaker harness for six sound channel outputs (6' sections of each)
  • Quick Start Guide
  • Owner’s Manual CD
  • Customer registration card

Additional items needed for operation:

  • Up to six 8-ohm speakers
  • Optional subwoofer
  • The appropriate DCC mobile decoders equipped with transponding or a TL-1 transponder
  • Digitrax DCC Command Station, cabs, and power boosters
  • Additional speaker wire if using a distance greater than 6’
  • Digitrax BDL-168 (or older BDL-162) Block Detectors
  • Digitrax RX-4s (eight total)


SurroundTraxx can accommodate up to six speakers per system, or five speakers and a subwoofer. The size and quality of these speakers are up to you and should be based on your layout design. However, we have a few helpful guidelines and requirements to help you achieve the best audio experience.

The speakers must be passive 8-ohm speakers rated between 5 and 25 watts. We recommend choosing speakers with a frequency response ranging from 80 to 16,000 hertz. If you plan to use a subwoofer, speakers with a frequency response of 150 to 16,000 hertz are sufficient, as the subwoofer will provide the bass.

Mobile Decoders and Transponders

SurroundTraxx is designed to operate on DCC layouts. In order to operate SurroundTraxx in transponding mode (multiple trains in multiple sound zones), you must have DCC mobile decoders with transponding installed in your locomotives. Alternatively, you may add separate transponders to any DCC mobile decoder that is already installed. To emphasize this point, when using SurroundTraxx to its full capabilities, you must either use decoders that come equipped with Digitrax transponding or purchase a TL-1 transponder to add to the locomotive. Sound decoders can also be installed in the locomotive, but are not required. Locomotives that aren’t equipped with transponders will still run on the layout, but will not be able to be dispatched or produce any sound through your SurroundTraxx system.

DCC Command Station, Cabs and Boosters

SurroundTraxx requires a Digitrax LocoNet-equipped command station in order to operate in any of its modes. For now, SurroundTraxx cannot be used with other systems.

Additional Speaker Wire

SurroundTraxx comes with 6’ sections of speaker wire for each sound channel output. If your layout requires more wire, you can add your own wire to the end of the wire harness included with your SurroundTraxx unit.

BDL-168 Block Detectors

To achieve the effect of sound traveling through your layout with your train, you must use Digitrax bi-directional block detectors known as BDL-168s. One BDL-168 will operate eight different blocks. Therefore, if your layout has more than eight blocks, you will need more than one BDL-168.

Digitrax RX-4s

Digitrax RX-4s are required in conjunction with BDL-168s, and you must have one for each block on your layout. For example, if you have 10 blocks you, will need 10 RX-4s for your layout.

Planning Your Layout

The SurroundTraxx User's Guide will guide you through the planning and installation process, from the initial planning stages to the final system configuration.

Installation involves these major steps:

  • Plan your layout
  • Define your track plan
  • Create a schematic
  • Divide and wire your layout into blocks
  • Define your sound zones
  • Identify speaker locations
  • Verify the detection is working

Plan Your Layout

By the time you begin planning for sound, you’ve probably already given a lot of thought to the other elements of your layout. Naturally, the extent of planning required varies by the complexity of the layout and its stage of completion when you begin installation of SurroundTraxx. We encourage you to enjoy the planning stages, taking time to consider the multiple factors in play.

If you are adding SurroundTraxx to a layout that is otherwise complete, you may find it helpful to take a test drive in transponder-free mode before finalizing the sound zones.

When deciding how to wire your layout the first factor is choosing which operating mode you would like to implement on your layout. This may change the set up and wiring of your layout. For instance if you wish to use SurroundTraxx in Transponder-free mode then you will wire the layout just as you would for any basic DCC layout. In other words, you wouldn’t need to divide the layout into blocks or add any of the transponding equipment offered by Digitrax. If, on the other hand you wish to use either 6-channel or 5-channel with a subwoofer mode, you will need to take into account two factors in the general wiring of your layout. The first of these factors is how many block detectors you need, and the second is how many sound zones you plan on having.

The table below lists some general size guidelines for a sound zone on your layout. As a reminder a sound zone and a block are not the same thing as a sound zone can encompass multiple blocks within one sound zone. If you intend to use single channel mode you can disregard this table, as the entire layout would be one sound zone.

Layout Size Sound Zone Size

Tabletop Layouts (4’x8’)

2' to 3' between speakers

Small Layouts

4' between speakers

Medium Layouts

6' between speakers

Large Layouts

8' between speakers

Define Your Track Plan

If you are adding SurroundTraxx to an existing layout, you likely already have a track plan in one form or another. Otherwise, the track plan is your first opportunity to begin planning for sound. The track plan is a scale drawing of your layout, reflecting its geographical realities: each curve, loop, straightaway, etc. It is a helpful tool in identifying challenges and potential tricky spots such as reverse loops and wyes.

The User's Guide shows an example layout to help illustrate the principles employed when planning for SurroundTraxx installation.

Create A Schematic

For the purpose of SurroundTraxx setup, a detailed electrical schematic is not required, but a basic schematic is an important step in separating the layout into blocks, which is a prerequisite to defining your sound zones.

Divide and wire your layout into Blocks

The schematic will help you assess the factors that affect the block divisions. For example, you wouldn’t want to place a block boundary in the middle of a siding. Instead, the boundary should occur at one end of the siding or the other. Likewise, a wye or yard should usually be confined to a single block. Even if you’re not using block detection with signaling devices, it’s helpful to plan your blocks as if signaling were part of the picture.

Define Your Sound Zones

A sound zone is the area covered by one speaker. You’ll want to revisit your track plan and schematic with the determined the block boundaries, as these resources together are a great help in defining the sound zones. Remember that the sound zones you define for SurroundTraxx relate to, but don’t necessarily equate to, the detection blocks. In other words, multiple blocks can be in one sound zone. Each SurroundTraxx unit supports up to six sound zones.

Identify Speaker Locations

Ideally, speakers should be placed as close to the center of your sound zones as possible, as seen in the example below. You may also want to consider the speaker's shape and size when deciding on speaker placement. Some speakers are easier to conceal than others, and this should be a consideration as you shop for speakers.

Ideally, the subwoofer should be mounted under the benchwork or on the floor. This provides optimal low-frequency response without causing vibration within the benchwork and scenery.

When installing speakers, you can conceal them in the benchwork, inside larger buildings or building facades, or behind greenery. You could also mount them on your ceiling or wall. If your layout incorporates mountainous terrain, you can build speaker compartments into hillsides. Wherever you decide to conceal the speakers, plan for easy access later in case of a loose speaker wire, failed speaker, or another maintenance issue. Self-amplified speakers will have onboard volume controls and possibly other controls, so be sure you can access them.

Sound Library

SurroundTraxx comes preloaded with its own sound library built from the quality sound files users have come to expect from SoundTraxx. Containing both diesel and steam prime movers, air horns, whistles, bells, exhaust chuffs, and more, this library gives the user the ability to customize the sounds of their locomotives.

If you aren't sure how to "build" your locomotive from the menu of sounds, start by visiting the section on our website about choosing the right sounds for your model. Selecting the Right Sounds for your Steam Locomotive will give you some insight into matching the available sounds to your steam engine. Selecting the Right Sound for your Diesel Locomotive will likewise point you in the right direction for your diesel models, beginning with matching the prime mover to the model. For those who want to further match the sounds to their prototype railroad, our Locomotive Airhorn History will prove invaluable.

Steam Sound Effects


  • Cross Compound
  • Poorly Maintained Cross Compound
  • Shay Style Cross Compound
  • Single Phase
  • SP Cab Forward
  • Vacuum Pump


  • Steam Bell 1
  • Steam Bell 2
  • Steam Bell 3
  • Steam Bell 4
  • Steam Bell 5
  • Steam Bell 6
  • Steam Bell 7
  • Steam Bell 8


  • Heavy Smokebox Blower
  • Light Smokebox Blower
  • Light Smokebox Blower 1
  • Light Logging Smokebox Blower
  • Medium Smokebox Blower


  • Early Draft Gear
  • Late Draft Gear
  • Link and Pin


  • Heavy Dynamo
  • Light Dynamo
  • Light Logging Dynamo
  • Medium Dynamo

Exhaust Chuffs

  • Heavy Steam 1
  • Heavy Steam 2
  • Light Steam 1
  • Light Steam 2
  • Light Logging
  • Medium Steam 1
  • Medium Steam 2
  • Medium Steam 3

Prime Movers

  • C Class
  • Heavy Steam
  • K-Class
  • Light Logging
  • Light Steam
  • Medium Steam
  • SP Heavy Steam
  • UP Medium Steam


  • B&O 3-Chime
  • C&S 74 Road Mix
  • C&S 74 Yard Mix
  • C&S 801
  • C-19 Road Mix
  • Climax  
  • Crosby 3-Chime
  • D&RGW C-19 Yard Mix
  • Frisco 1522
  • GBL 40
  • K-27 463
  • K-36 487
  • K-36 488
  • K-36 489
  • K-36 489 "Sticky Chime"
  • K-37 497
  • Lehigh Valley
  • LMS Black 5 Class
  • LMS Brittania Class
  • LNER
  • LNER A4 Class
  • Logging Peanut
  • Lunkenheimer 3-Chime
  • N&W Class A 1218
  • N&W Class J 611
  • Nathan 5-Chime Road Mix
  • Nathan 5-Chime Yard Mix
  • PRR Banshee
  • Reading 6-Chime
  • Santa Fe Freight
  • Southern 3-Chime
  • Southern Single Chime
  • SP 6-Chime
  • SP Airhorn
  • SP GS-4 4449
  • Tweetsie
  • UP Big Boy 4018
  • USRA 6-Chime
  • Westside Shay 12
  • Westside Shay 14


  • Short Whistle
  • Steam Hiss

Diesel Sound Effects


  • Alco Diesel
  • Electronic - Modern
  • EMD Diesel
  • Fairbanks - Morse


  • Diesel Air Compressor
  • Modern GE Air Compressor


  • Early Draft Gear
  • Late Draft Gear
  • Link and Pin

Prime Movers

  • Alco 244
  • Alco 251 V12
  • Baldwin
  • EMD 567
  • EMD 645 Turbo
  • EMD 710 Turbo
  • Fairbanks Morse
  • GE FDL 16
  • GE Gevo 12
  • Railbus


  • 1929 Aooogah Horn
  • Car Horn
  • Hancock Air Whistle
  • Holden K5 H
  • Holden M3 H
  • Leslie A125 Bronze
  • Leslie A200
  • Leslie Combo
  • Leslie RS5T
  • Leslie S2M
  • Leslie S3L
  • Leslie S3LR
  • Leslie S5T
  • Nathan P5 Early
  • Nathan K3L
  • Nathan K5LA
  • Nathan M3
  • Nathan M5
  • Nathan P3
  • Nathan P5 Modern
  • Nathan P5A
  • RGS Goose
  • Wabco A2
  • Wabco E2


  • Dynamic Brakes
  • Engine Start-Up
  • Engine Shut-Down
  • Radiator Fans
  • Short Horn


If you hook one speaker to SurroundTraxx, and an identical speaker to a Tsunami decoder, will the sound output of SurroundTraxx be equal to that of the Tsunami?

No, SurroundTraxx provides a larger audio amplifier than that of the Tsunami. SurroundTraxx outputs are rated for up to 25-watt speakers.

Can I load my own sound files into SurroundTraxx?

No, SurroundTraxx comes with an extensive sound library that allows you to fully customize your locomotives. Inside this library are over 10,000 different sound combinations of horns/whistles, bells, compressors, couplers, and prime movers/exhaust chuffs.

How do I configure the locomotives?

SurroundTraxx has an internal database called the Roundhouse. You will configure, customize, and store the settings for each locomotive here. You will then assign these settings to the same address as your locomotive’s mobile decoder. This will ensure that SurroundTraxx dispatches the sounds for that locomotive at the same time that you run your model.

How are the locomotives assigned to a consist?

Locomotives stored inside SurroundTraxx don’t get assigned to a consist like mobile decoders. However, if you run a set of locomotives together, SurroundTraxx will dispatch each one as they are selected so they will make sound at the same time. Up to six locomotives can make sound at once.

Is any power drawn from the track power while SurroundTraxx is in operation?

No, SurroundTraxx has its own external power supply and does not affect your track voltage outputs.

Will SurroundTraxx affect my onboard decoders?

No, SurroundTraxx doesn’t send any signals through the rail on your layout. It instead receives the same information that’s going to your track, so it will not affect any decoders installed on your layout. Only your command station will send DCC packets to your decoders.

Can I run a locomotive with an onboard decoder at the same time as SurroundTraxx? Can I configure my onboard sound decoders to work with SurroundTraxx?

Yes, SurroundTraxx will work at the same time as an onboard decoder without affecting it. The two can be used in conjunction by adjusting individual volumes on both your SurroundTraxx unit and any SoundTraxx Tsunami Digital Sound Decoder. That can create an interesting effect; for example turning the volume of the horn and bell up in the sound decoder, down in SurroundTraxx, while adding volume to the low frequency sounds, such as a diesel prime mover in SurroundTraxx in order to take advantage of the larger speakers.

How many locomotives on the layout can have sound through SurroundTraxx at one time?

SurroundTraxx provides sound for up to six locomotives at a time.

Is there a limit to the number of SurroundTraxx systems I can link together?

No, you may, however, want to have more than one subwoofer if you get beyond two SurroundTraxx systems in a layout.


Is the Roundhouse the ONLY way to configure the locomotives?

No, the locomotive can also be configured using Ops mode programming with your DCC cab.

How many locomotives can be stored in the SurroundTraxx roundhouse at a time?

The Roundhouse in SurroundTraxx can store up to 99 locomotives at a time. You can also delete and add locomotives as you choose, making it easy to add a visiting piece of equipment to your pike.

If I have more than one SurroundTraxx system, can I move the Roundhouse information from one system to another?

No, you will have to manually enter the settings into each system.


Will SurroundTraxx play sound for more than one locomotive in a sound zone at the same time?

Yes, SurroundTraxx follows each locomotive around the layout, therefore it will produce sound for each of the six locomotives regardless of whether they are all in the same zone or spread throughout the layout. This can make some really cool effects as trains pass each other on the main.

Can I have more than six sound zones?

There are only six sound zones available per SurroundTraxx system. If more than six sound zones are desired then the addition of another SurroundTraxx system is required.