amphion One25A Announces First 3 Way Active Studio Monitor User Manual

: June 15, 2024
: amphion

Table of Contents

One25A Announces First 3 Way Active Studio Monitor
Specifications
Introduction
Safety
Warranty and Support
Company Profile
FAQ
References
Read User Manual Online (PDF format)
Download This Manual (PDF format)

One25A Announces First 3 Way Active Studio Monitor

Specifications

Model: One25A
Reference manual: 10/2023
Product Type: Monitor
Country of Manufacture: Finland
Warranty: Two years

Introduction

The Amphion One25A is a monitor that combines advanced acoustic
design, refined signal path, and high-level resolution. It offers
the benefits of active design without compromising on audio
quality.

Safety

Before using the product, please read and follow these safety
instructions:

Do not use the apparatus near water.
Clean only with a dry cloth.
Do not block any ventilation openings.
Install the product according to the manufacturer’s
instructions.
Avoid installing near heat sources such as sunlight, radiators,
or amplifiers that produce heat.
Avoid covering or placing objects on top of the unit to prevent
heat buildup.
Do not tamper with the polarized or grounding-type plug.
Unplug the apparatus during lightning storms or when not in use
for long periods.
Refer servicing to qualified personnel if the apparatus has
been damaged or exposed to moisture.
These monitors can produce high sound pressure levels. Adjust
the volume within safe limits to prevent hearing damage.

WARNING: To reduce the risk of fire or electric
shock, do not expose this apparatus to rain or moisture. Do not
expose the equipment to dripping or splashing. Ensure that no
objects filled with liquids are placed on the equipment. To
disconnect the equipment from the AC mains, unplug the power supply
cord.

Warranty and Support

The Amphion One25A comes with a two-year warranty. The product
is handmade in Finland, meeting the Association for Finnish Work’s
Key Flag Symbol mark of origin requirements.

Company Profile

Amphion Loudspeakers Ltd. was established in 1998. They
specialize in designing and building loudspeakers that provide
honest and accurate sound reproduction. All their products are
handmade in Finland to ensure long-lasting listening quality.

FAQ

1.  **Q: Can the One25A be used near water?**

A: No, it is not recommended to use the apparatus near
water.

```
1.  **Q: What is the warranty period?**
```

A: The One25A comes with a two-year warranty.

1.  **Q: Can I clean the product with a wet

cloth?**

A: No, clean only with a dry cloth to prevent damage.

```
1.  **Q: Where are Amphion products  
```
manufactured?**

A: All Amphion products are handmade in Finland.

One25A
Reference manual 10/2023

beautifully honest
2

Contents

Introduction

4

Safety

6

Warranty and support

8

Instructions

10

Philosophy

12

Technical specifications

14

Technologies and features

16

Controls and connections

20

Lights

22

Setup guide

24

Acoustic centre point

26

Soffit mounting

27

Boundary control

28

Immersive

30

3

Welcome

Introduction
Over a decade has passed since the introduction of Amphion’s studio monitor line. Pushing the acoustic design and keeping the products electrically simple created an intuitive and effective tool, which has been embraced by the world’s top sound engineers. Going against the norm with the passive design was naturally bold and risky, but we managed to get our ideas through. Amphion’s design focus is always result – not technology – oriented. We have never opposed the basic principle of active speakers. We simply felt we could achieve better resolution and naturalness by applying passive design at the time.
Active approach has certain benefits ie. matching the amps to drivers, overload/ overdrive protection and limiters, and the option of making really steep filters and cut-off points. However, many active designs lose resolution due to their highly complex signal paths. As we strongly believe in elegant and refined signal paths, we are not against the use of DSP. But we feel strongly that unnecessary DSP and AD/DA stages should always live outside of the speaker.

4

Presenting Amphion One25A … a monitor true to Amphion’s core strengths of advanced acoustic design, refined signal path, and high level resolution – enhanced with the benefits of active design without any of the downsides.
Anssi Hyvönen Founder & Managing Director, Amphion Loudspeakers Ltd.
5

Safety warnings
6

Safety
1. Please read and follow these instructions before using the product.
2. Do not use this apparatus near water. 3. Clean only with a dry cloth. 4. Do not block any ventilation openings. 5. Install in accordance with the
manufacturer’s instructions. 6. Do not install near any heat sources such
as sunlight, radiators, heat registers, or other apparatus (including amplifiers) that produce heat. 7. The unit generates heat especially during prolonged operation at intensive levels. Please do not
cover or place objects on top. 8. Do not defeat the safety purpose of the polarized or grounding-type plug. A polarized plug has
two blades with one wider than the other. A grounding-type plug has two blades and a third grounding prong. The wide blade or the third prong are provided for your safety. If the provided plug does not fit into your outlet, consult an electrician for replacement of the obsolete outlet. 9. Protect the power cord from being walked on or pinched, particularly at plugs, convenience receptacles, and the point where they exit from the apparatus. 10. Use only with the stand, bracket, or table which is sturdy and stable enough to support the units substantial weight. Ensure the monitors do not tip/fall and cause injury or damage. 11. Any terminals marked with the preceding symbol are HAZARDOUS LIVE and any wiring connected to these terminals must be installed by an INSTRUCTED PERSON or with readymade leads or cords.

12. Unplug this apparatus during lightning storms or when unused for long periods of time. 13. Refer all servicing to qualified service personnel. Servicing is required when the apparatus has
been damaged in any way, such as power-supply cord or plug is damaged, liquid has been spilled or objects have fallen into the apparatus, the apparatus has been exposed to rain or moisture, does not operate normally, or has been dropped. 14. These monitors can produce high sound pressure levels (SPL). Exposure to high volume has the potential to cause hearing damage. Adjust the system’s volume level to remain within safe limits.
WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE. DO NOT EXPOSE THIS EQUIPMENT TO DRIPPING OR SPLASHING AND ENSURE THAT NO OBJECTS FILLED WITH LIQUIDS, SUCH AS VASES, ARE PLACED ON THE EQUIPMENT. TO COMPLETELY DISCONNECT THIS EQUIPMENT FROM THE AC MAINS, DISCONNECT THE POWER SUPPLY CORD PLUG FROM THE AC RECEPTACLE. THE MAINS PLUG OF THE POWER SUPPLY CORD SHALL REMAIN READILY OPERABLE.
7

Warranty

Warranty and support

Amphion Create products come with a two-year warranty against defects in materials and our workmanship. For warranty or out-of-warranty service, in the first instance please contact your original dealer and provide a copy of the original sales receipt. If you require additional assistance, please contact your local sales representative or distributor. If you have difficulty making contact with either of the above, please contact our headquarters. Please do not return or ship any product to Amphion Loudspeakers Ltd. nor its resellers without prior authorisation.

two years warranty

Handmade in Finland

Amphion Loudspeakers Ltd. is awarded the right to use the Association for Finnish Work’s Key Flag Symbol mark of origin. This mark is granted to Finland-based organizations that manufacture their products in Finland, having a minimum domestic content of 50 percent.

8

Company profile

Amphion Loudspeakers Ltd. was established in 1998. We design and build loudspeakers that are characterised by honest and accurate sound reproduction. All products are handmade in Finland (and the Amphion amplifiers are assembled in Finland) to ensure enduring listening quality.

Hear more

www.amphion.fi
Social media www.facebook.com/AmphionLoudspeakers twitter.com/amphion_fi www.youtube.com/user/AmphionLoudspeakers www.instagram.com/amphion_loudspeakers

9

Unpacking

Instructions
180 o
Handmade in Finland

Connecting
10

0

-1

+1

-2

+2

-4

+4

-7

+7

dB

Handmade in Finland

Care

Maintenance

Please contact your local Amphion dealer or sales representative for additional guidance on cabinet, driver, or electronic maintenance. For more information, you can also contact Amphion headquarters or our regional offices in Asia (Japan) and North America (USA).

11

Hear it all Truthful sound

Philosophy
Your ears are the most important tool in your studio. Providing them with detailed, reliable information is the only way for making right, stress-free decisions. Pushing the acoustic design allows our products to have a simple signal path, as well as ensure transparency, resolution, and exceptional time and phase coherence. All products use time-adjusted drivers and low crossovers. This leads into pointsource-like behavior and seamless driver integration. Rock solid “phantom” center, life-like 3D imaging and a wide and deep sweet-spot are characteristic of all Amphion products.
Amphion’s Uniformly Directive Dispersion (U/D/D) allows the speakers to work in a predictable and acoustically-stable manner in all rooms. Amphion’s fifth generation waveguide ensures driver integration, eliminates cabinet diffractions, and produces a uniform and even response throughout a broad frequency band. The result is a wide, even listening area, which provides predictable results in your current room as well as your next. Use of sealed cabinet instead of a vent not only makes for a more natural energy transfer and improved bass definition, but also enhances the midrange clarity.

12

Work smarter

Achieving more in less time with minimum revisions, while keeping your clients happy, is a must in today’s world. To achieve this, your monitoring must translate well and guide you to focus on the essential information. Being able to totally trust your monitors leads into substantial time savings and peace of mind – even when working towards the tightest deadlines. World class translation and ability to make fast intuitive decisions help achieve consistent results equally well for stereo and all immersive formats.

13

Technical specifications

Operating principle Tweeter Mid Bass Crossover point Amplifier power
Power consumption (idle) Power consumption (max) Max SPL Frequency response Connections
Mains Measurements (H x W x D) Weight

Active, 3-way, sealed cabinet 25 mm / 1″ titanium 15 cm / 5¼” aluminium 25 cm / 10″ aluminium 100 Hz / 2000 Hz Bass 700 W Tweeter & Midrange 2 x 205W THD + N 0,002% 35W 350W 105 dB 22 – 55 000Hz (-3dB) Balanced XLR Input 1x Female XLR, pin 2-hot 230 V / 50 Hz or 115 V / 60 Hz (Factory preset) 316 x 510 x 487 mm 41 kg / 91 lb

14

Frequency response

100.0 dBSPL
90.0

80.0

70.0

60.0

50.0

20

100

1k

180.0 CLIO
Deg 108.0 36.0
-36.0 -108.0
-180.0 10k Hz 20k
15

Internal view

Technologies and features

2

4

1

3

16

1 Waveguide

Amphion’s Uniformly Directive Dispersion (U/D/D) allows the speakers to work in a predictable and acoustically stable manner in all rooms. Amphion’s signature fifth generation waveguide ensures driver integration, eliminates cabinet diffractions and produces a uniform and even response through a broad frequency band. The result is a wide, even listening area, which allows you to trust your monitors in your current room as well as your next.

2 Sealed dual cabinet

The internal bracing is designed both as a stiffening support structure and as a physical-energy dispersion filter. It utilizes the mass of the sub-driver, and how it is connected to the bracing structure, to control the resonance of the whole enclosure in a desirable way. The glue-joints of the enclosure are specifically designed to control various structural stiffnesses as well as enclosure edge vibration dispersion.

3 Isolated chambers New midrange driver and tweeter are in an isolated sealed chamber which minimizes the bass woofer’s negative effects like pressure changes, leading to high midrange and treble resolution ensuring crystal clear transparency.

4 Acoustic symmetry

The channel between the two compartments ensures acoustic symmetry for the midrange drivers, and acts as a transfer-insulator/filter by separating the two chambers. The efficient surface damping qualities of the material between the compartments acts as a vibrational and acoustical dampening filter for the whole enclosure.
17

Back
18

Technologies and features

One25A

AUDIO INPUT

LOW FREQUENCY CONTOUR

4

3

AC MAINS POWER

1

2

1 Simple, refined signal path

Active speakers are typically complex with many sequential active stages – each with countless electronic components. As a result, the sonic integrity tends to get compromised. In DSP-based solutions, the situation is even worse: transparency, depth, and detail is lost because of both conversion and processing. The beauty of passive speaker crossovers lies in their simplicity, which helps to maintain a high level of audio resolution. The One25A follows this design philosophy, but as an active speaker, it is radically different. It could be described as a line-level passive crossover, which is buffered with ultra-clean FET buffers. This gives us the best of both worlds.

2 Removable Amp Pack

Instead of placing the amplifiers and power supply inside the monitor, where they are negatively affected by physical vibration and magnetic forces of drivers, all the electronics are housed outside the cabinet. The rigid, well- isolated steel enclosure can also be removed for soffit mounting. Placing components in a well-cooled enclosure ensures maximum ventilation and lowest possible operating temperature.

3 Boundary control Amphion’s 8-step low frequency adjustment boundary control (+/-7dB). Please refer to page 28 for more information.

4 Protection circuit Amphion’s overload protection circuitry. Please refer to page 22 for more information.

19

Controls and connections
Back

1

2

20

34

1 Input

This is the XLR output for your mains. If you are using an unbalanced destination, it is recommended to leave XLR pin 3 unconnected.

2 Boundary Control Amphion’s 8-step low frequency adjustment boundary control (+/-7dB). Please refer to page 32 for more information.

3 Power input

IEC power connector. Selected between the 100-240V range by users region. Please contact Amphion support if questions occur.

4 Power switch

This is the power switch I = ON, O = OFF

! PLEASE NOTE! Always turn power off before inserting or removing cables.

21

Lights

Blue White Red

Standby / On mute Wait for white light
Power on Normal operation
Overload protection Power amplifiers overload protection is active (audio level and spectrum is limited for monitor protection).

Protection circuitry

In order to keep the signal path as short and resolving as possible, the protection circuitry is kept separate from the audio signal path and it remains inactive until limiting is needed.

Instead of muting, cutting the signal, or skewing the frequency balance, the limiting circuitry is designed to keep the workflow undisturbed and the music playing. Technically, it can be considered to be a soft, padded wall instead of a typical brutal brick-wall approach. This gentle approach will help prevent damage to the speaker drivers, but understands real-life situations where playback levels can get overlyloud occasionally. To prevent damage to speaker drivers and human ears, it is always advisable to turn the volume down when the red light is activated.

22

23

Studio-monitor placement

Setup guide
60°

Display Position

Studio-monitor stencil

For both stereo and immersive installations, it is important to maintain symmetry.

24

25

Acoustic centre point

Between the drivers

The acoustic center point of Amphion One25A is located between the drivers (under the waveguide, on top of the woofer), which allows them to be used both vertically and horizontally. Line the acoustic centre point to your ear-level for optimal performance. Depending on your listening distance and room size, the tweeter can be placed both inward and outward. With shorter distances you can increase the size of the soundstage by placing it outward, while with longer distances it can be placed inward.

Removable amp

Soffit mounting

Due to our sealed design the One25A is well suited for soffit mounting. The amplifier pack can be detached and separated from the speaker and a rack mountable Amp Pack version is available. Please contact your local Amphion partner or headquarters for additional guidance.

26

27

8-steps
28

Boundary control
One25A’s boundary control system allows fine tuning the bass response in eight steps i.e. +/- 1dB, 2dB, 4dB, and 7dB (measured at 20Hz).
Placing speakers close to boundaries such as walls tends to cause bass buildup, which can be compensated easily with a turn of a dial, which is located next to the XLR input. Please note that boundary control allows both decreasing and increasing the bass level to fine tune the response to different rooms, wall density, placement and personal preference. Note that the floor is also considered a boundary, which means that the mounting height of the speaker will affect the response at the lowest frequencies.
The adjustment is a smooth shelf-type curve mostly operating at frequencies below 150 Hz. Even if results sound sonically fine, use caution when applying correction as large amounts of boost will use more amplifier power and result in longer driver excursion. Note that the speaker is designed to work in most rooms of various size without any need for adjustment.

Boundary control

10

CLIO

dBu

5

0

-5

-10

-15

5

10

20

50

100

200 Hz 500

1k

2k

5k

10k

20k

29

Immersive

Seamless and uniform
30

Immersive environments set new demands for monitoring. Precise imaging, defined depth information, and immaculate phase behaviour are a must when placing objects on the 3D-grid. As the number of channels grow, even the smallest shortcomings in monitoring lead to a lack of cohesion. Amphion’s unique acoustic design ensures an exquisite, three-dimensional, reference quality soundscape that’s needed to achieve industry leading results.
Our professional studio monitors can be mixed and matched completely seamlessly, as their acoustic design, tonal characteristics, and dispersion are precise and uniform. All Amphions utilize proprietary waveguides, sealed enclosures, tweeters with similar crossovers, and drivers with tight production tolerance – which lead to a seamless sound-field and contribute to sonic conformity and consistency in all settings. Our advanced acoustic design minimizes electrical clutter and allows harnessing the full power of the latest signal processing devices, as well as room correction or other types of advanced software. Due to their phase coherence and pinpoint imaging, Amphion monitors translate particularly well to any playback devices, as they allow you to correctly reproduce information in all planes – including width, height, and depth.
For surround or immersive formats, we recommend that all speakers are aimed directly at the listening position, to ensure consistent balance and focus across the whole sound field. Please refer to page 28.

LCR
(ONE25A)
LFE
(FLEXBASE25)
OVERHEAD
(ONE12, ONE15, ONE18)
SURROUND
(ALL MODELS)

This is an example, many different configurations can be created. Bass Extension shown in sideview.
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Amphion Loudspeakers Ltd. Telkkistentie 2 70460 Kuopio Finland
+358 17 2882100 info@amphion.fi amphion.fi
AE/RMKR/INEN/1023