Audio T Verdict
The QUAD S-1 is proof that a genuinely small loudspeaker does not have to settle for ordinary high-frequency technology. Its 45 x 12mm true-ribbon tweeter gives this compact standmount much of its character, partnered with a 100mm woven Kevlar bass/mid driver and carefully tuned rear reflex loading.
At just 285mm tall, the S-1 works particularly well where space is at a premium, but it deserves to be treated as a proper Hi-Fi loudspeaker rather than simply placed wherever it fits. QUAD recommends stand mounting, with the ribbon around seated ear height and enough breathing space behind the rear-firing port.
With 84dB sensitivity it is not especially efficient, so we would favour a capable amplifier with useful current delivery rather than choosing purely from the minimum wattage figure. Get the amplifier and positioning right and the S-1 can produce an impressively open, detailed and spacious presentation from a remarkably compact cabinet.
QUAD S-1 Ribbon Standmount Speakers
The QUAD S-1 is the smallest standmount model in the S Series, combining the company's true-ribbon high-frequency technology with a compact woven-Kevlar bass/mid driver and rear-ported enclosure.
It was designed for listeners who want a physically discreet loudspeaker without abandoning the wide dispersion, transient response and fine detail associated with QUAD's ribbon-driver designs.
- Compact 2-way standmount loudspeaker
- 45 x 12mm true-ribbon tweeter
- 100mm woven Kevlar bass/mid driver
- Rear-firing bass-reflex port
- 3.2kHz crossover frequency
- 84dB sensitivity at 2.83V/1m
- 8-ohm compatible nominal impedance
- 4.2-ohm minimum impedance
- 25 to 150W recommended amplifier power
- 58Hz to 20kHz frequency response at ±3dB
- 55Hz bass extension at -6dB
- 6.7-litre cabinet volume
- Dual HF/LF speaker terminals
- Suitable for conventional single-wiring or bi-wiring
- Layered MDF and high-density particleboard cabinet
- Rounded front and rear cabinet edges
- Black Oak, Sapele Mahogany, Piano Black and Piano White finishes
QUAD True-Ribbon Tweeter
The defining feature of the S-1 is its 45 x 12mm true-ribbon high-frequency driver.
A ribbon tweeter works differently from a conventional dome tweeter. Rather than attaching a separate voice coil to a diaphragm, the lightweight conductive ribbon itself operates within the magnetic field and performs the dual role of electrical conductor and sound radiator.
This removes the need for the additional moving mass associated with a conventional voice-coil assembly.
A Modern Ribbon Designed for Real-World Use
Ribbon tweeters have historically had a reputation for being delicate, but QUAD designed the S Series unit specifically to address that concern.
The ribbon uses a sandwich construction to improve robustness and is fully immersed within a powerful magnetic field.
The aim is to preserve the low moving mass and rapid response that make ribbon drivers attractive while making the unit sufficiently durable for use with modern amplifiers.
The Ribbon Is Both Voice Coil and Radiator
In a conventional dynamic tweeter the electrical voice coil moves a separate dome or diaphragm.
In the S-1 ribbon, the conductive element itself responds to the magnetic field and radiates the sound.
Reducing the number of mechanically coupled moving parts helps the high-frequency driver respond quickly to small changes in the signal.
Controlled High-Frequency Dispersion
QUAD deliberately controls the way the ribbon distributes sound through the room.
Horizontal dispersion is designed to remain wide enough to provide good coverage across the listening area, while vertical dispersion is more tightly controlled.
The narrower vertical behaviour helps reduce the amount of high-frequency energy directed towards the floor and ceiling.
Why Tweeter Height Matters
Because vertical ribbon dispersion is deliberately controlled, the S-1 performs best with the tweeter positioned approximately at seated ear height. A correctly chosen speaker stand is therefore more than a cosmetic accessory.
100mm Woven Kevlar Bass/Mid Driver
Below the ribbon sits a 100mm woven Kevlar cone responsible for both bass and midrange reproduction.
Using one driver across this broad part of the spectrum keeps the S-1's architecture relatively simple while avoiding an additional crossover point through the vocal region.
The woven structure is designed to combine low mass with useful stiffness, helping the cone maintain controlled behaviour as frequency rises towards the crossover region.
One Driver Handles Bass and Midrange
The S-1 is a true 2-way design.
The 100mm cone handles frequencies from the bass through the midrange until the crossover transfers responsibility to the ribbon tweeter at 3.2kHz.
There is no separate dedicated midrange unit, helping keep the cabinet exceptionally compact.
3.2kHz Crossover
The crossover frequency is specified at 3.2kHz.
The crossover network divides the incoming amplifier signal between the woven Kevlar bass/mid driver and ribbon tweeter so that each works over the frequency range for which it was designed.
A good crossover has to do considerably more than simply split frequencies: the acoustic output, electrical behaviour and relative level of the two drive units must also integrate correctly around the crossover region.
Rear-Firing Bass Reflex Port
The S-1 uses a carefully tuned rear-firing reflex port to augment low-frequency output from the small cabinet and 100mm driver.
The port uses energy from the rear of the bass/mid driver and tunes it to contribute usefully at low frequencies.
This allows greater bass extension than a similarly sized sealed enclosure could normally provide, but it also means distance from the wall behind the speaker affects the result.
55Hz Bass Extension
QUAD specifies bass extension to 55Hz at -6dB, with the main ±3dB response beginning at 58Hz.
For a loudspeaker only 285mm tall with a 100mm bass/mid driver, this makes the S-1 suitable for a wide range of music in smaller and medium-sized rooms without automatically requiring a subwoofer.
Does the S-1 Need a Subwoofer?
Not necessarily. For conventional stereo music listening, its 55Hz published bass extension may be entirely sufficient depending on room size, speaker positioning and the type of music you enjoy.
A properly integrated subwoofer can add the lowest octave for electronic music, organ, film soundtracks and listeners wanting greater low-frequency scale.
The important word is integrated: adding more bass is only worthwhile if the subwoofer blends naturally with the S-1 rather than drawing attention to itself.
84dB Sensitivity
Sensitivity is specified at 84dB for 2.83V at 1 metre.
That is relatively low compared with many larger loudspeakers, so the S-1 benefits from an amplifier with sensible power reserves.
This does not mean enormous amplifier wattage is essential, but it does mean we would avoid assuming that the smallest speaker automatically requires the smallest amplifier.
Small Speaker Does Not Mean Easy Speaker
The S-1's compact size can be misleading. At 84dB sensitivity it requires more amplifier output to reach a given listening level than a 90dB speaker under otherwise identical conditions. Room size, listening distance and how loudly you listen should all be considered when choosing the amplifier.
25 to 150W Recommended Amplifier Power
QUAD's current specification recommends amplification between 25 and 150 watts.
This is a broad compatibility range rather than an instruction to use a 150W amplifier.
A quality lower-powered amplifier may be entirely appropriate in a smaller room, while greater power reserves can be useful at longer listening distances or when higher playback levels are required.
Why Underpowered Amplifiers Can Still Cause Damage
An amplifier that runs out of usable power can be driven into clipping, creating distortion that can be harmful to loudspeakers.
For this reason, simply choosing the lowest wattage amplifier because the speakers are physically small is not necessarily the safest approach.
We would rather use a suitable, clean-running amplifier with sensible headroom and control the listening level appropriately.
8-Ohm Compatible Nominal Impedance
QUAD describes the S-1 as 8-ohm compatible.
Like almost every real loudspeaker, its electrical impedance is not fixed at one value across the entire frequency range.
The published minimum is 4.2 ohms.
This is another reason amplifier matching should consider more than nominal impedance alone.
58Hz to 20kHz Frequency Response
The published frequency response is 58Hz to 20kHz at ±3dB.
That range covers the majority of musical fundamentals and the conventional audible high-frequency spectrum from a very compact enclosure.
Compact 6.7-Litre Cabinet
The current QUAD specification gives the internal cabinet volume as 6.7 litres.
Its physical dimensions are:
- Height: 285mm
- Width: 156mm
- Cabinet depth: 240mm
- Additional rear-terminal allowance: approximately 30mm
This makes the S-1 one of the easiest conventional QUAD Hi-Fi loudspeakers to accommodate where room space is limited.
Layered Cabinet Construction
The enclosure uses alternating layers of MDF and high-density particleboard.
QUAD uses the different materials as part of a sandwich construction intended to reduce cabinet-panel resonance.
A loudspeaker cabinet should ideally provide a rigid, quiet structure for the drive units rather than adding its own delayed vibration to the music.
Rounded Cabinet Edges
The front and rear upper edges are smoothly rounded rather than forming an entirely square box.
This gives the S-1 its distinctive compact appearance while softening the visual bulk of the enclosure.
Four Current Finish Options
QUAD currently lists the S-1 in:
- Black Oak
- Sapele Mahogany
- Piano Black
- Piano White
The wood-effect and lacquered options allow the S-1 to work visually in both traditional and more contemporary rooms.
Stand Mounting Is Recommended
QUAD states that the S-1 should ideally be stand mounted.
A proper speaker stand places the ribbon at a useful listening height and gives the cabinet a stable platform without surrounding it with furniture that may interfere with the rear port.
It also gives you considerably more freedom when adjusting distance from the rear and side walls.
Can the S-1 Go on a Shelf?
Yes. QUAD's manual states that the S-1 may be placed on a rigid shelf that is separate from the rest of the system.
However, because the reflex port fires backwards, shelf depth and rear-wall distance become particularly important.
If you have the choice, a suitable stand generally makes positioning and bass tuning easier.
Start Around 200mm From the Rear Wall
QUAD recommends beginning with the loudspeakers at least 200mm from the wall behind them.
Moving them closer to the wall generally increases perceived bass output, but placing the port too close to the boundary can make the bass less distinct.
Moving the speakers further into the room usually gives cleaner bass definition and greater freedom to adjust toe-in.
Use the Rear Wall as a Tuning Tool
If the S-1 sounds a little lean, moving it slightly closer to the rear wall can increase low-frequency reinforcement. If the bass sounds thick or indistinct, bring the speaker further into the room. Small changes can make a surprisingly large difference with a rear-ported design.
Allow Around 300mm From Side Walls
QUAD's manual uses approximately 300mm from the side walls as a useful starting point.
Every room behaves differently, so these figures should be treated as the beginning of the setup process rather than a rigid final position.
Two to Three Metres Apart
For conventional stereo listening, QUAD suggests placing the speakers approximately two to three metres apart and roughly equidistant from the listening position.
In a smaller room or nearfield system the practical spacing may naturally be reduced.
Toe Them Slightly Towards the Listener
QUAD recommends angling the loudspeakers slightly inward towards the listening seat.
Toe-in affects both image focus and the amount of direct high-frequency energy reaching the listener.
Rather than assuming one angle is correct, begin with a modest inward angle and adjust by ear.
Keep the Ribbon Around Ear Height
The tweeters should sit at approximately the listener's seated ear level.
This is particularly relevant to a ribbon design because the S-1 intentionally controls vertical high-frequency dispersion.
Dual HF and LF Terminals
The rear panel provides separate terminal pairs for the high-frequency and low-frequency sections of the crossover.
The upper terminals feed the ribbon-tweeter network and the lower terminals feed the bass/mid section.
Removable metal links connect the two sections for normal single-wire operation.
Standard Single-Wire Connection
For the simplest installation, leave the supplied terminal links in position and connect one speaker cable to each loudspeaker.
Maintain consistent positive and negative polarity between amplifier and speakers.
Incorrect polarity between the left and right channels can weaken central imaging and make bass reproduction less coherent.
Bi-Wiring
The S-1 can also be bi-wired.
Bi-wiring uses separate cable runs from the same amplifier channel to the HF and LF terminal sections, with the factory links removed.
QUAD's S Series manual actively recommends bi-wiring where practical, although a high-quality conventional single-wire connection remains perfectly valid.
Remove the Terminal Links Before Bi-Wiring
If separate HF and LF cable runs are used, remove the metal linking straps between the terminal sections first. For normal single-wire operation, leave those links securely in place.
Bi-Amping
The separated crossover inputs also make bi-amplification possible with suitable amplification.
One amplifier channel or amplifier can then feed the HF section while another feeds the LF section.
Bi-amping needs considerably more care than ordinary bi-wiring, particularly when matching amplifier gain and system configuration, so we recommend discussing the intended setup before connecting it.
50-Hour Running-In Period
QUAD recommends allowing approximately 50 hours of normal use for the loudspeakers to run in.
This does not mean they need to be played continuously or at unusually high volume.
Simply use the system normally at sensible levels and allow the mechanical components to settle through normal operation.
Suitable for Nearfield Systems
The S-1's small enclosure also makes it useful for high-quality nearfield systems where a conventional full-size standmount would simply occupy too much space.
Audio T has previously partnered the S-1 with compact electronics in desktop and low-volume systems, where the combination of small cabinet dimensions and ribbon-tweeter detail makes particular sense.
Suitable for Home Cinema Surrounds
QUAD also identifies the S-1 as suitable for rear-effects use within an S Series multichannel system.
Its compact dimensions can make it easier to accommodate as a surround speaker while retaining the same ribbon technology used throughout the wider S Series.
S-1 or S-2?
The S-1 is the smallest standmount in the range, while the QUAD S-2 is the larger alternative.
QUAD S-1
- 100mm woven Kevlar bass/mid driver
- 45 x 12mm true ribbon
- 84dB sensitivity
- 58Hz - 20kHz response
- 55Hz bass extension
- 285mm high
- Best where space is tight
QUAD S-2
- Larger woven Kevlar bass/mid driver
- Same S Series ribbon concept
- Higher sensitivity
- Greater low-frequency extension
- Larger enclosure
- Better suited where greater scale is required
The S-1 is the obvious choice where cabinet size and room space take priority. If you have room for a larger standmount and want greater bass extension and output, the S-2 is worth comparing in the same system.
Audio T Experience With the S-1
The S-1 has been used across several Audio T systems over the years, from traditional integrated-amplifier setups to compact desktop and low-volume systems.
Our original S-1 introduction highlighted its unusual combination of a 285mm-high cabinet, 100mm woven Kevlar driver and ribbon tweeter, while more recent Audio T system guides have continued to use it where compact dimensions and high-quality stereo reproduction are both priorities.
Key Features
- QUAD S-1
- Compact standmount loudspeaker
- 2-way architecture
- Rear-vented enclosure
- 45 x 12mm true-ribbon tweeter
- Ribbon sandwich construction
- Controlled horizontal dispersion
- Controlled vertical dispersion
- 100mm woven Kevlar bass/mid driver
- 3.2kHz crossover
- 84dB sensitivity
- 8-ohm compatible nominal impedance
- 4.2-ohm minimum impedance
- 25 to 150W recommended amplifier power
- 58Hz - 20kHz frequency response
- 55Hz bass extension at -6dB
- 6.7-litre cabinet volume
- 285mm cabinet height
- 156mm cabinet width
- 240mm cabinet depth
- Approximately 30mm additional rear-terminal allowance
- 5.2kg net weight
- Layered MDF and high-density particleboard cabinet
- Dual HF/LF terminals
- Single-wire connection
- Bi-wire capability
- Bi-amp capability
- Stand mounting recommended
- Approximately 50-hour running-in period
- Black Oak finish
- Sapele Mahogany finish
- Piano Black finish
- Piano White finish
Frequently Asked Questions
Is the QUAD S-1 still current?
Yes. QUAD continues to list the S-1 within its current S Series and passive-speaker range.
Is the S-1 a bookshelf or standmount speaker?
QUAD describes it as a bookshelf speaker, but also states that it should ideally be stand mounted. Audio T therefore describes it as a compact standmount loudspeaker while recognising that it can also work on a suitable rigid shelf.
Is it a 2-way speaker?
Yes. One 100mm bass/mid driver is partnered by one true-ribbon tweeter.
What size is the ribbon tweeter?
45 x 12mm.
Is it a true ribbon?
Yes. QUAD specifies a true-ribbon high-frequency driver.
How does a ribbon tweeter work?
The lightweight conductive ribbon operates within a magnetic field and acts as both the electrical conductor and the sound-radiating element rather than using a conventional separate voice coil and dome.
Is the ribbon fragile?
QUAD developed the S Series ribbon using a sandwich construction specifically to provide greater robustness than older delicate ribbon designs. Normal care and sensible amplifier use are still required.
What is the bass/mid driver made from?
A 100mm woven Kevlar cone.
Is the S-1 rear ported?
Yes. It uses a rear-firing reflex port.
What is the crossover frequency?
3.2kHz.
What is the sensitivity?
84dB for 2.83V measured at 1 metre.
Is 84dB considered sensitive?
It is relatively low compared with many larger loudspeakers, so amplifier quality and available power should be considered carefully, particularly in larger rooms or at longer listening distances.
What amplifier power does QUAD recommend?
The current manufacturer specification recommends 25 to 150W.
What is the nominal impedance?
QUAD describes the S-1 as 8-ohm compatible.
What is the minimum impedance?
4.2 ohms.
What is the frequency response?
58Hz to 20kHz at ±3dB.
How deep does the bass go?
QUAD specifies bass extension to 55Hz at -6dB.
Do I need a subwoofer?
Not automatically. The S-1 can operate as a conventional stereo loudspeaker on its own. A subwoofer is an optional addition where greater very-low-frequency extension is required.
What is the cabinet volume?
QUAD's current dedicated S-1 product specification gives 6.7 litres.
How big is the S-1?
The cabinet is 285mm high, 156mm wide and 240mm deep, with approximately another 30mm required at the rear for the terminal assembly.
How much does it weigh?
QUAD publishes a net weight of 5.2kg.
Should I use speaker stands?
QUAD states that the S-1 should ideally be stand mounted.
Can I put it on a bookshelf?
Yes, provided the shelf is suitably rigid and there is enough room behind the speaker for its rear-firing reflex port to operate correctly.
How far should it be from the rear wall?
QUAD recommends at least approximately 200mm as a starting point. Moving it closer generally increases bass reinforcement, while moving it further away can improve definition.
How far from the side walls?
Around 300mm is QUAD's recommended starting point, although the final position should be established in the actual room.
How far apart should the speakers be?
For a conventional stereo arrangement, QUAD suggests roughly two to three metres apart and approximately equidistant from the listening position.
Should the speakers be toed in?
Yes. QUAD recommends angling them slightly towards the listener, with the final amount of toe-in adjusted by listening.
How high should the tweeter be?
Approximately level with the listener's ears when seated.
Can the S-1 be bi-wired?
Yes. Separate HF and LF terminals are provided.
Do I remove the terminal links for bi-wiring?
Yes. The links remain fitted for ordinary single-wiring and should be removed when the HF and LF sections are independently cabled.
Can the S-1 be bi-amped?
Yes, with suitable amplification and correct system configuration.
How long do the speakers take to run in?
QUAD recommends approximately 50 hours of normal use.
Can the S-1 be used as a surround speaker?
Yes. QUAD identifies the S-1 as suitable for effects-channel use within a multichannel S Series installation.
What finishes are currently available?
QUAD currently lists Black Oak, Sapele Mahogany, Piano Black and Piano White.
What is the difference between the S-1 and S-2?
The S-1 is the more compact model. The S-2 uses a larger bass/mid driver and cabinet and offers greater sensitivity and bass extension, making it worth considering where there is more room available.
Related QUAD Products and Audio T Guides
Why Buy the QUAD S-1 From Audio T?
Compact speakers can be particularly sensitive to the system and room around them. With the S-1, amplifier power, listening distance, stand height and the spacing around its rear reflex port all have a genuine influence on performance.
Audio T can demonstrate the S-1 with suitable amplification, compare it with the larger S-2 and help establish the best stand and room position before you commit to the final system.
- In-store demonstrations
- Amplifier matching
- 84dB sensitivity and power guidance
- Speaker impedance matching
- Stand selection
- Tweeter-height setup
- Rear-wall positioning advice
- Toe-in and stereo-image setup
- Single-wire and bi-wire guidance
- Speaker-cable advice
- S-1 versus S-2 demonstrations
- Compact-room system planning
- Nearfield system advice
- Subwoofer integration where appropriate
- Home-cinema surround integration
- Ongoing after-sales support
Contact your local Audio T store to arrange a demonstration or discuss whether the QUAD S-1 is the right compact loudspeaker for your amplifier, room and listening position.