Audio T Verdict
The Arcam SA45 is a flagship all-in-one music system for customers who want the convenience of modern streaming without sacrificing the power, connectivity or upgrade potential of a serious Hi-Fi separates system.
Its fifth-generation Class G amplifier delivers 180W per channel into 8-ohm loudspeakers, giving it the control and dynamic headroom required for demanding standmount speakers, substantial floorstanders and larger listening rooms.
High-resolution network streaming, an 8.8-inch colour display, Dirac Live Room Correction, HDMI eARC, separate MM and MC phono stages, balanced analogue connections and dual subwoofer outputs make it considerably more flexible than a conventional integrated amplifier.
The SA45 also provides balanced and unbalanced pre-amplifier outputs, optical and coaxial digital outputs and Pre Amp Mode, giving the system room to grow. It has no CD mechanism, internal music storage, USB computer audio input or wired headphone socket, but for customers seeking a powerful and beautifully integrated music system, it is an exceptionally complete solution.
Arcam Radia SA45 Streaming Integrated Amplifier
The Arcam SA45 combines a high-resolution network streamer, digital-to-analogue converter, stereo pre-amplifier, fifth-generation Class G power amplifier, MM and MC phono stages and Dirac Live Room Correction within one full-width component.
Connect a suitable pair of passive loudspeakers and the SA45 can form the centre of a complete system for streaming services, internet radio, vinyl, television sound, digital sources, analogue components and music stored across a home network.
A large 8.8-inch bonded display presents album artwork, track information and system settings, while the Arcam Radia app provides network setup, music browsing and everyday control from a compatible phone or tablet.
Fifth-Generation Class G Amplification
Arcam's fifth-generation Class G architecture uses more than one power-supply level to combine low-level refinement with the ability to produce substantial output when the music demands it.
During ordinary listening, the amplifier operates from its lower-voltage supply region. An additional power-supply rail becomes available during larger and more demanding musical peaks.
This approach provides greater electrical efficiency than operating a similarly powerful amplifier continuously in Class A, while retaining the current delivery and dynamic ability needed to control demanding loudspeakers.
Read our
guide to Arcam amplification and Class G technology
for further background.
180W per Channel into 8 Ohms
The SA45 delivers 180W per channel into 8-ohm loudspeakers with both channels operating across the full 20Hz to 20kHz audio range.
This provides substantial reserves for larger rooms, less sensitive speakers and customers who enjoy listening at realistic levels.
Arcam specifies harmonic distortion of 0.002% at 80% of the rated 8-ohm output under its stated measurement conditions.
300W per Channel into 4 Ohms
Output increases to 300W per channel into a 4-ohm load at the manufacturer's stated 1kHz measurement condition.
The increase demonstrates the ability of the amplifier and power supply to provide considerably greater output as loudspeaker impedance falls.
Nominal impedance is only part of the speaker-matching process, so sensitivity, impedance variation, room size, listening distance and preferred volume should also be considered.
Our
amplifier power and loudspeaker matching guide
explains how these specifications work together.
The 4-Ohm Figure Is Measured at 1kHz
The 180W rating is specified with both channels driven from 20Hz to 20kHz into 8 ohms.
The 300W rating is specified into 4 ohms at 1kHz and should not be presented as a full-bandwidth measurement.
Balanced Analogue and Digital Architecture
The SA45 uses balanced analogue and digital signal paths within its internal audio architecture.
Balanced circuit arrangements can help reject common electrical noise and maintain separation between the positive and negative halves of the audio signal.
A balanced XLR source input, balanced pre-amplifier outputs and balanced subwoofer outputs are provided for compatible external equipment.
Linear Toroidal Power Supply
A newly developed linear toroidal power supply supports the amplifier, streaming platform and sensitive audio circuitry.
Arcam has designed the supply to reduce electrical noise around the analogue and digital stages while retaining the current delivery required by the powerful Class G output section.
A separate switching supply operates during standby, reducing energy consumption when the main amplifier is not in use.
High-Resolution Streaming Platform
The SA45 uses a six-layer digital audio and streaming platform with a continuous ground plane designed to keep unwanted noise and interference away from the sensitive audio components.
Compatible network and locally stored music can be played at up to 32-bit/384kHz, with DSD supported up to DSD256.
Gapless playback allows live albums, classical works, concept albums and continuous mixes to move from one track to the next without an artificial pause.
Spotify, TIDAL and Qobuz Connect
Spotify Connect, TIDAL Connect and Qobuz Connect allow the SA45 to be selected directly from within each service's own application.
Music is delivered to the amplifier through the home network rather than being continuously routed through the controlling phone or tablet.
Available sound quality and features depend on the selected service, subscription, recording and region.
Apple AirPlay and Google Cast
Apple AirPlay allows compatible iPhone, iPad and Mac users to send audio to the SA45 across the home network.
Google Cast provides similar functionality from supported applications on Android, Apple and computer devices.
These network technologies provide a convenient way to play from compatible applications that do not offer their own direct Connect integration.
Roon Ready
Roon Ready certification allows the SA45 to operate as a recognised network endpoint within a compatible Roon system.
Roon provides detailed metadata, music discovery, library organisation, signal-path information and multiroom playback.
A separate Roon Server and suitable Roon subscription are required.
The SA45 Is a Roon Endpoint
The amplifier receives music from a separate Roon Server located on a compatible computer, NAS drive or dedicated server.
It does not contain the server software or store a complete Roon library by itself.
Arcam Radia App
The Arcam Radia app guides initial Wi-Fi setup and provides access to internet radio, podcasts, presets, USB media and compatible music stored across the local network.
The app can also manage playback and provide access to system settings from a compatible phone or tablet.
The controlling device and SA45 should normally be connected to the same local network.
Internet Radio, Podcasts and UPnP
Internet radio provides access to stations from the UK and around the world without requiring a conventional radio aerial.
Podcast support adds spoken-word programmes, interviews and specialist content through the Arcam Radia app.
UPnP compatibility allows the amplifier to access suitable music libraries stored on a computer, NAS drive or other media server connected to the same home network.
External Services Can Change
Radio stations, podcasts, streaming services and regional availability may change independently of the amplifier.
Some services require a separate account or paid subscription.
USB Music Playback
A rear USB-A socket accepts a compatible USB flash drive containing supported music files.
Files held on the drive can be browsed and selected using the Arcam Radia app.
Supported formats include AAC, AIFF, ALAC, FLAC, MP3, OGG, WAV, WMA and DSD.
The USB Socket Is Not a Computer Audio Input
The USB-A connection is intended for compatible storage playback and amplifier software updates.
The SA45 cannot be connected directly to a computer for operation as a USB DAC.
No Internal Music Storage
The SA45 does not contain a user-accessible hard drive or SSD.
Personal music should be stored on compatible USB media, a computer or a network-attached storage device.
ESS Hyperstream IV DAC Technology
The digital section uses ESS Hyperstream IV DAC technology in a balanced internal configuration.
Advanced jitter reduction and the carefully designed six-layer circuit board help protect the conversion stage from timing errors and electrical noise.
Streaming sources and external digital inputs are converted by the SA45 before being passed to its pre-amplifier and Class G power stages.
Selectable DAC Filters
Four selectable DAC filters allow the behaviour of the digital-to-analogue conversion stage to be adjusted.
The available options balance frequency response, phase behaviour and pre or post-ringing in different ways.
Audible differences can be subtle and system dependent, so the filters are best compared using familiar music.
8.8-Inch High-Resolution Display
The bonded 8.8-inch front display presents album artwork, track information, source selection, presets and system settings.
Its larger size makes playback information easier to read from a normal listening position than the smaller displays fitted to many streaming amplifiers.
Display and illuminated control brightness can be adjusted to suit daytime or evening listening.
Dirac Live Room Correction
Dirac Live measures how the loudspeakers and room interact across the intended listening area.
The software can then create a correction filter intended to improve frequency balance, timing and integration within the room.
Multiple measurement positions are used and the completed filter is stored within the SA45 for selection during everyday listening.
Read our
introduction to Arcam and Dirac Live Room Correction
for more background.
Dirac Live Requires Initial Calibration
Calibration is completed using Dirac Live software on a compatible Windows PC or Mac.
The supplied measurement microphone connects to the computer using the included USB cable rather than plugging directly into the amplifier.
Measurement Microphone Included
Arcam includes a measurement microphone and five-metre USB cable for the Dirac Live setup process.
The microphone should be positioned at ear height and kept within a clear line of sight of the loudspeakers during each measurement sweep.
Arcam recommends taking at least five measurements across the intended listening area before designing and exporting a correction filter.
HDMI eARC for Television Sound
HDMI eARC allows a compatible television to send stereo audio to the SA45 through one HDMI cable.
Films, television programmes, games and streaming-video applications can then use the Arcam amplifier and connected Hi-Fi loudspeakers.
Compatible television volume commands can operate the SA45, while automatic input switching can select HDMI when television audio begins.
Our
guide to improving television sound with a stereo system
explains the benefits of this type of arrangement.
Use the Television's ARC or eARC Socket
Connect the HDMI cable to the television socket specifically labelled ARC or eARC.
A conventional HDMI input without Audio Return Channel support will not send television sound back to the amplifier.
The SA45 Is a Stereo Amplifier
HDMI eARC is provided for compatible television audio rather than surround-sound processing or video switching.
Set the television to stereo PCM if an encoded multichannel format does not produce sound.
Four Conventional Digital Inputs
Two optical Toslink inputs and two coaxial RCA inputs allow suitable external digital sources to use the SA45's internal DAC.
Compatible products may include a CD transport, television, games console or another digital audio source.
These inputs support compatible 16-bit and 24-bit stereo PCM at sample rates up to 192kHz.
Optical and Coaxial Digital Outputs
Optical Toslink and coaxial RCA outputs allow compatible digital audio to be passed to an external DAC, digital recorder or another suitable component.
These connections add useful flexibility for customers who want to use an alternative conversion stage or distribute digital audio elsewhere within a system.
Format compatibility should be checked with the connected external product.
Inputs and Outputs Are Separate
The SA45 provides four digital inputs as well as dedicated optical and coaxial output sockets.
Check the rear-panel labels carefully before connecting a source or external DAC.
Three RCA Analogue Line Inputs
Three stereo RCA line inputs provide connections for conventional analogue source components.
Suitable products include a CD player, tuner, cassette deck, external DAC or another source with a standard line-level output.
Line-level products must not be connected to either of the dedicated phono inputs.
Balanced XLR Analogue Input
A stereo pair of balanced XLR inputs is provided for a compatible source component.
Balanced connections can provide improved rejection of electrical interference, particularly when long interconnects are required or several mains-powered components share the same equipment area.
The source must provide a suitable balanced analogue output. An XLR connector alone does not guarantee that every product uses the same internal circuit arrangement.
Moving-Magnet and Moving-Coil Phono Inputs
Separate MM and MC phono inputs allow a broad range of turntables and cartridges to connect without requiring an external phono stage.
Use the moving-magnet input with a suitable MM or compatible high-output cartridge, and the moving-coil input with a suitable low-output MC cartridge.
A grounding terminal is provided for turntables that use a separate earth lead.
Browse our
turntable range
for suitable source options.
Use the Correct Phono Input
Confirm the cartridge type before connecting the turntable.
Connecting a line-level source to either phono input can produce severe overload and distortion.
Turntables with Built-In Phono Stages Use a Line Input
When the turntable's own phono stage is active, connect it to one of the conventional analogue inputs.
Do not pass the signal through both the turntable's phono stage and the SA45 phono input.
Bluetooth 5.4 Audio Reception
Bluetooth 5.4 allows compatible phones, tablets and computers to play directly through the amplifier.
The wireless platform includes Snapdragon Sound, AAC, Bluetooth LE Audio and Auracast support with compatible equipment.
The amplifier can remember multiple paired source devices, while the configurable maximum Bluetooth input volume can help prevent unexpectedly high playback levels.
Wireless Bluetooth Headphone Output
The SA45 can transmit sound from its connected sources to compatible Bluetooth headphones.
Headphones are paired and selected through the Audio menu on the front display.
This allows vinyl, streaming, television and other connected sources to be heard wirelessly.
No Wired Headphone Socket
The SA45 supports compatible wireless Bluetooth headphones but does not provide a front or rear wired headphone connection.
Bluetooth Input and Output Cannot Operate Together
Bluetooth headphones cannot be used while Bluetooth is selected as the amplifier's input source.
Select streaming, phono, HDMI, analogue or another digital input when listening through wireless headphones.
Auracast Audio Sharing
Auracast allows the SA45 to broadcast audio to multiple compatible Bluetooth LE Audio receiving products.
This can be useful for shared headphone listening and accessibility applications.
Conventional Bluetooth headphones do not automatically support Auracast, so compatibility should be confirmed before purchase.
Balanced and Unbalanced Pre-Amplifier Outputs
The SA45 provides both stereo RCA and balanced XLR pre-amplifier outputs.
These variable outputs follow the selected source and volume setting and can feed a suitable external power amplifier.
The
Arcam PA240 Class G power amplifier
provides one possible external amplification option with balanced and unbalanced inputs.
Pre Amp Mode
Pre Amp Mode disables the SA45's internal power amplifier while leaving the source selection, streaming platform, volume control and pre-amplifier outputs active.
This allows the SA45 to operate as a streaming pre-amplifier with an external stereo power amplifier or pair of suitable mono power amplifiers.
Disable Pre Amp Mode When Using the Speaker Outputs
The internal power amplifier does not drive connected passive loudspeakers while Pre Amp Mode is enabled.
Leave the setting off during normal integrated-amplifier operation.
RCA and Balanced Subwoofer Outputs
Two RCA subwoofer outputs and two corresponding balanced XLR subwoofer outputs provide flexible connection for one or two suitable powered subwoofers.
The Subwoofer Config menu tells the SA45 whether no subwoofer, one subwoofer or two subwoofers are connected.
Dirac Live can then measure the combined loudspeaker, subwoofer and room response as part of the calibration process.
Browse our range of
powered subwoofers
for suitable system options.
Use One Connection Type per Subwoofer
Do not connect both the RCA and XLR output to the same subwoofer input arrangement unless the subwoofer manufacturer specifically supports that configuration.
Use either the balanced or unbalanced connection appropriate to the complete system.
Ethernet, Wi-Fi and System Control
Dual-band Wi-Fi and wired Ethernet connect the SA45 to streaming services, the Radia app, Roon and compatible local music libraries.
Ethernet can provide greater reliability where wireless coverage is weak or the local network is congested.
RS232 and infrared control connections support compatible automation and custom-installation systems.
Trigger input and output connections help coordinate standby operation with other compatible components.
Network Standby and Automatic Standby
Network Standby keeps the amplifier visible to compatible apps and services while it is in standby.
Switching Network Standby off reduces energy consumption but may require the amplifier to be switched on manually before it appears within an app.
The Eco Timer places the SA45 into standby after approximately 20 minutes without playback or user interaction and can be disabled where required.
Add the Arcam CD5 CD Player
The
Arcam Radia CD5
provides dedicated compact-disc and USB-storage playback in matching Radia styling.
Its analogue RCA output can use the CD5's internal DAC, while its optical or coaxial output allows the SA45 to carry out digital-to-analogue conversion.
Comparing both connection methods provides a useful way to decide which DAC and analogue stage best suits the complete system.
SA45 or Separate ST25 and Amplifier?
The SA45 combines streaming, source control, room correction and powerful amplification in one enclosure.
A separate
Arcam ST25 network streamer
and integrated or pre and power amplifier system provides greater freedom to upgrade individual components.
The right approach depends on available space, system complexity, future upgrade plans and whether reducing the number of boxes is a priority.
Speaker Matching
The SA45's 180W output and Class G architecture make it suitable for a wide selection of high-quality standmount and floorstanding speakers.
It is particularly relevant where the loudspeakers benefit from substantial current delivery, the room is large or the preferred listening level requires greater headroom.
The right combination still depends on loudspeaker impedance, sensitivity, room acoustics, placement and personal taste.
Read our
amplifier and speaker system-balancing guide
for further advice.
Protection and Ventilation
The SA45 monitors conditions including excessive temperature, amplifier faults and power-supply faults.
If protection is activated, switch the amplifier off and inspect the loudspeaker cables, ventilation and connected equipment before restarting it.
The amplifier is designed to run warm and should be placed on a firm, level surface with open space around its ventilation openings.
Do Not Use a Closed Cabinet Without Ventilation
Restricted airflow can increase operating temperature and cause the amplifier to enter protection.
Do not place another component on top, as this can obstruct the heatsink and expose the other product to heat.
Keep the Amplifier Away from Turntables
Avoid placing a turntable directly on top of or immediately beside the SA45.
A phono cartridge may pick up mechanical vibration or electromagnetic hum from substantial amplifier power supplies.
SA35 and SA45 Comparison
Arcam SA35
- 120W per channel into 8 ohms
- 200W per channel into 4 ohms at 1kHz
- 6.5-inch high-resolution display
- Three RCA line inputs
- MM and MC phono inputs
- RCA pre-amplifier output
- Dual RCA subwoofer outputs
- Dirac Live Room Correction
- More compact 12kg construction
View the Arcam SA35
Arcam SA45
- 180W per channel into 8 ohms
- 300W per channel into 4 ohms at 1kHz
- 8.8-inch high-resolution display
- RCA and balanced XLR source inputs
- MM and MC phono inputs
- RCA and balanced pre-amplifier outputs
- RCA and balanced subwoofer outputs
- Optical and coaxial digital outputs
- Substantial 17kg construction
System Matching
Well Suited To
- Customers wanting a flagship all-in-one music system
- Medium and larger listening rooms
- Demanding standmount and floorstanding speakers
- Spotify, TIDAL and Qobuz Connect users
- Apple AirPlay and Google Cast playback
- Roon Ready music systems
- MM and MC turntable systems
- Balanced analogue source components
- Television sound through HDMI eARC
- Single or dual powered-subwoofer systems
- Rooms that may benefit from Dirac Live
- Future external power-amplifier upgrades
Check Before Buying
- No USB computer audio input
- No wired headphone socket
- No internal music storage
- No compact-disc mechanism
- No surround-sound decoding
- Dirac setup requires a compatible PC or Mac
- Auracast requires compatible receiving products
- Bluetooth input and headphone output cannot operate together
- One pair of passive loudspeakers connects directly
- The amplifier weighs 17kg
- Substantial ventilation space is required
Setup Guidance
- Use Ethernet where Wi-Fi reliability is limited
- Set televisions to stereo PCM where required
- Use the correct MM or MC phono input
- Use the Radia app for network and USB playback
- Complete Dirac measurements in a quiet room
- Configure the connected subwoofer arrangement
- Use either RCA or XLR for each external connection
- Disable Pre Amp Mode when using passive speakers
- Maintain correct loudspeaker polarity
- Keep the amplifier well ventilated
Browse our
streaming amplifiers
,
network music streamers
,
passive loudspeakers
,
turntables
,
powered subwoofers
and
analogue, digital and speaker cables
, or explore the complete
Arcam range at Audio T
.
Finish
Radia Black
The SA45 uses Arcam's understated Radia Black styling with substantial aluminium casework, rounded edges, solid controls and discreet yellow detailing.
Key Features
- Flagship all-in-one streaming integrated amplifier
- Fifth-generation Arcam Class G amplification
- 180W per channel into 8 ohms
- 300W per channel into 4 ohms at 1kHz
- Balanced analogue and digital audio architecture
- Linear toroidal power supply
- Six-layer digital audio and streaming platform
- ESS Hyperstream IV DAC technology
- Streaming up to 32-bit/384kHz
- DSD playback up to DSD256
- Gapless playback
- Spotify Connect
- TIDAL Connect
- Qobuz Connect
- Apple AirPlay
- Google Cast
- Roon Ready
- Internet radio and podcasts
- UPnP network-library playback
- USB flash-drive music playback
- Dual-band Wi-Fi and Ethernet
- Arcam Radia app control
- 8.8-inch high-resolution colour display
- Four selectable DAC filters
- Dirac Live Room Correction
- Measurement microphone and USB cable included
- HDMI eARC and ARC television input
- Two optical digital inputs
- Two coaxial digital inputs
- Optical digital output
- Coaxial digital output
- Three stereo RCA line inputs
- One stereo balanced XLR input
- Dedicated moving-magnet phono input
- Dedicated moving-coil phono input
- RCA and balanced XLR pre-amplifier outputs
- Two RCA subwoofer outputs
- Two balanced XLR subwoofer outputs
- Pre Amp Mode
- Bluetooth 5.4 audio reception
- Bluetooth wireless-headphone transmission
- Snapdragon Sound
- Bluetooth LE Audio
- Auracast
- RS232 and infrared control
- Trigger input and output
- Automatic and network standby settings
- Remote control included
- Plastic-free packaging
- Radia Black finish
Frequently Asked Questions
What is the Arcam SA45?
It is a flagship streaming integrated amplifier combining network playback, a DAC, Class G amplification, MM and MC phono stages, balanced connections and Dirac Live Room Correction.
How powerful is the SA45?
It delivers 180W per channel into 8 ohms across 20Hz to 20kHz and 300W per channel into 4 ohms at the manufacturer's stated 1kHz condition.
What does Class G mean?
Class G uses more than one power-supply level, allowing the amplifier to operate efficiently during normal listening while making additional voltage and power available for demanding musical peaks.
Does it include music streaming?
Yes. It supports Spotify Connect, TIDAL Connect, Qobuz Connect, AirPlay, Google Cast, Roon, internet radio, podcasts, UPnP and USB media.
What is the maximum streaming resolution?
Compatible PCM music is supported at up to 32-bit/384kHz, with DSD playback up to DSD256.
Is it Roon Ready?
Yes. A separate Roon Server and suitable Roon subscription are required.
Does it have HDMI eARC?
Yes. Connect a compatible television through its ARC or eARC HDMI socket.
Does it decode Dolby Atmos?
No. The SA45 is a stereo amplifier rather than a surround-sound receiver. Configure the television for compatible stereo audio.
Does it include Dirac Live?
Yes. A measurement microphone and five-metre USB cable are supplied for calibration using a compatible Windows PC or Mac.
Can I connect two subwoofers?
Yes. Two RCA and two balanced XLR subwoofer outputs are provided for one or two suitable powered subwoofers.
Can I connect a turntable?
Yes. Separate moving-magnet and moving-coil phono inputs are provided for suitable cartridges.
Does it have balanced XLR connections?
Yes. The SA45 provides a stereo balanced source input, balanced pre-amplifier outputs and balanced subwoofer outputs.
Does it have digital outputs?
Yes. One optical Toslink and one coaxial RCA digital output are provided.
Can it be used as a USB DAC?
No. The rear USB-A connection supports compatible storage playback and software updates rather than direct computer audio.
Can it transmit to Bluetooth headphones?
Yes. Compatible Bluetooth headphones can be paired and selected through the Audio menu.
Does it have a wired headphone socket?
No. Private listening is available through compatible Bluetooth headphones.
Can Bluetooth input and headphones be used together?
No. Select a different source when transmitting audio to Bluetooth headphones.
Can it be used only as a streaming pre-amplifier?
Yes. Pre Amp Mode disables the internal power amplifier while leaving the source, streaming and variable pre-amplifier outputs active.
Can it play music from a USB drive?
Yes. Compatible music stored on a USB flash drive can be browsed through the Arcam Radia app.
Does it contain internal music storage?
No. Personal music can be stored on a compatible USB drive, computer or network-attached storage device.
What is the difference between the SA35 and SA45?
The SA45 provides greater amplifier power, a larger display, a balanced XLR source input, balanced pre-amplifier and subwoofer outputs, digital outputs and more substantial construction.
How large and heavy is the SA45?
It measures 432mm wide, 390mm deep and 140mm high and weighs 17kg, so it requires a substantial and well-ventilated equipment shelf.
What is included in the box?
The package includes the SA45, mains lead, remote control, two AAA batteries, measurement microphone, five-metre USB cable, quick-start guide and safety documentation.
Why Buy From Audio T?
- Demonstrations with suitable high-quality standmount and floorstanding speakers
- Direct comparison with the Arcam SA35
- Comparison with separate streamer and amplifier systems
- Class G amplifier and loudspeaker-matching advice
- Arcam Radia app and network setup
- Spotify, TIDAL and Qobuz Connect guidance
- Roon Ready system advice
- Dirac Live measurement and calibration assistance
- Single and dual-subwoofer setup guidance
- HDMI eARC television configuration
- MM and MC turntable and cartridge matching
- Balanced XLR and RCA connection guidance
- Bluetooth and Auracast compatibility advice
- Pre-amplifier and external power-amplifier setup
- Ethernet, Wi-Fi and UPnP troubleshooting
- Speaker cable and interconnect recommendations
- Ventilation and equipment-rack advice
- Home demonstrations may be available
- Part exchange available on suitable existing equipment
- Ongoing system, streaming and setup support
Contact your local Audio T store
to arrange a demonstration or discuss matching the Arcam SA45 with suitable loudspeakers, sources and subwoofers.