Technical2018-10-03T16:11:54+00:00
Quality in every piece.

THE BEST NORWEGIAN PRODUCT SINCE THE CHEESE CUTTER

There is no question that we thoroughly enjoy what we do, and while some may call us geeks, we wear it with pride. There are a painstaking amount of hours involved with developing any small part for our products, be it the material composition of the driver cones, or even something as miniscule as the shape, size and material choice for speaker terminals. We have a habit of spending a lot of time and effort to get everything just right. There are no coincidental design features on Arendal Sound products.

This section contains descriptions of the technical aspects of Arendal Sound products. Please continue reading on, if you like getting to know all the technical details.

WAVEGUIDE TWEETER

THE HEART OF ALL ARENDAL SPEAKERS

WAVEGUIDE TWEETER

THE HEART OF ALL ARENDAL SPEAKERS

The heart of all Arendal speakers, our Tweeter utilizes a 28mm synthetic soft dome with custom designed, matching waveguide. The soft dome itself is sourced from the high end stable of Dr. Kurt Mueller. It is very light weight, totally pistonic to ultra high frequencies, optimally damped, produced to exceedingly tight tolerances and specifically chosen for its sweet sound character and consistent frequency response.

The role of the waveguide is to take an already excellent tweeter and provide refinements to the tweeter’s performance. The size and shape, although appearing rather simple is in fact the result of painstaking modeling, testing and refinement. In precisely controlling directivity across the tweeter’s frequency range, we are able to broaden top end dispersion, which the tweeter naturally wants to beam straight ahead and focus frequencies at the bottom end of the tweeters range, which naturally want to spread out in all directions. This provides a more consistent polar response across the tweeters entire range and provided a close match to the dispersion pattern of the mid-bass driver it works with, simplifying crossover design.

HIGH EFFICIENCY, HIGH POWER MOTOR

The motor of this tweeter is a Tour de Force. All components are bespoke designs for Arendal Sound, extensively FEA optimized. The result is a very wide bandwidth, high efficiency, low distortion tweeter capable of being crossed over at very low 1500Hz, even at very high powers. This is truly a rare combination of such low crossover point, high output capability and clean sound.

•  Large, high grade neodymium ring magnet
•  High temp polyimide CCAW wire
•  Underhung voice coil design
•  Copper and aluminum shorting rings
•  Ultra low viscosity Ferrofluid contributes to voice coil cooling and ensures the best possible transient response
•  Large aluminum heatsink/shorting ring lowers distortion and prevents thermal compression.

HYBRID ALUMINUM & HDF WAVEGUIDE ASSEMBLY

The final piece to Arendal’s tweeter performance is mating the dome with the custom matched, proprietary waveguide, entirely optimised in-house. The waveguide serves several purposes, augmenting tweeter performance to a level that no flat baffle mounted single dome solution could reproduce:

•  Increased efficiency by controlling lower frequency dispersion – Typically a 6dB gain
•  Very low distortion due to increase in bottom end efficiency
•  Precise Polar Response control (sometime referred to as directivity response control)
•  Low crossover frequency (approx. 1 octave lower than without the waveguide)
•  Excellent directivity transition from mid/woofer to tweeter

AIR FLOW VENTING

The air chambers, venting and damping materials found behind the dome and surround are optimized to create a very well controlled impedance, void of secondary resonance spikes that typically result in electrical phase shifts that present an awkward load for amplifiers and further smear the sound, adding a harsh character.

8″ WOOFER

MASSIVE & CLEAN

8″ WOOFER

MASSIVE & CLEAN

The 6.5” and 8” woofers in the 1723 series are built upon the same core fundamentals as the the 13.8” subwoofer, but with application specific details changed. The woofer cones does not have the glass fibre reinforcement of the 13.8” as it is already stiff enough and the bass material’s inherent self-damping with its proprietary cone treatment is chief quality. An entirely bespoke design, the mid-woofers are optimised to cover a very wide frequency range from 1500Hz, down to the lowest bass notes without a hint of cone resonance. Distortion is closely related to how far the cone and motor has to move and for a given volume level. Size presents it’s own engineering challenges and the motor, suspension and diaphragm all must be delicately balanced to be able to cover the critical midrange frequencies without coloration.

WE USE:

1. CCAW (Copper Clad Aluminium Wire) in the voice coil, balancing the lightness of aluminium, with the conductivity of copper.

2. An aluminum shorting ring to reduce inductance, increase frequency bandwidth and lower distortion, whilst benefiting from the greater heat dissipation of a larger voice coil.

3. Suspension FEA analysed to deliver symmetrical travel, lowering non-linear distortion

4. Klippel analysed, lightweight, long fiber pulp cones, treated with a custom formulation for inherent self damping, that remains pistonic through its operating range and beyond.

5. Voice coil venting to reduce physical and thermal compression, maintaining a hugely dynamic response.

MULTIPLE DRIVERS

Multiple drive units are combined to further reduce Doppler distortions and augment bass output and power handling. The result is clean, dynamic, high output capability, maintaining composure and subtle details.

After thorough optimization and testing (using FEA, Klippel and other methods) of aluminum shorting rings with a focused field design, the result is a linear magnetic field over a wide range of input levels, ultra-low distortion, low inductance, and very dynamic bass.

Symmetrical suspension consists of critical components such as the NBR surround, Connex spider, and integrated tinsel leads. All combined to create very high excursion capability with an exceptionally linear suspension. Again, this contributes to high output and low distortion at all operating frequencies.

Air flow venting underneath the dust cap (vents in cone body) and spider (vents in the basket) is added for two very important reasons. First, air heat from the voice coil is forced away with each stroke of the cone diaphragm. This continuous exchange of air mitigates thermal compression and increases the woofer’s overall power handling capability. Second, the airflow relieves asymmetric compliancy and noises (ie, distortion) due to non-linear compression and rarefaction of air typically trapped under the dust cap and spider. Typical vented pole designs will be limited in effectiveness due to the lack of airflow volume. Meaning, at the highest power and excursion where the airflow is needed most, the pole vent alone will not be sufficient.

Shielding is added to all drivers except for 1723 S models.

13,8″-WOOFER

Size matters

13,8″-WOOFER

Size matters

Why 13.8”? The 25% larger surface area, when compared to a 12” driver, yields a woofer that requires less excursion and power to achieve the same SPL levels. The result is lower distortion, higher power handling and most importantly – tighter bass. Every part for this driver has been custom tooled to deliver high output, low distortion, accurate bass.

DESIGN FEATURES

Ultra-high temp polyimide former with CCAW voice coil (copper clad aluminum wire) for low mass, high motor force and optimal thermal dissipation.

Benefits:

  • 85% Aluminum / 15% Copper allows larger wire for more surface area.
  • 68% as conductive as copper, but only 40% the mass for lighter weight.
  • Ultra-high temp Polyimide prevents insulation breakdown at high power levels (aka “burnt voice coil”)

After thorough optimization and testing (using FEA, Klippel and other methods) we refined a motor featuring multiple aluminum shorting rings with focused field “T” pole design. The result is a linear magnetic field over a long voice coil throw, with very low inductance.

The symmetrical suspension consists of a heavily analysed NBR surround and Connex spider with integrated tinsel leads. All combined to create a very high excursion with linear suspension. Again, contributing to high output and low distorting accurate bass.

HYBRID CONE

Our unique hybrid cone of long fiber pulp and fiberglass, takes advantage of the pulp’s superior stiffness to weight ratio, with the additional rigidity of fiberglass to deliver a driver of massive durability that inherently inert and self damping. The result is a cone that achieves optimal pistonic motion at all frequencies it is asked to produce and beyond.

DRIVER SHIELDING

Shielding is added to all drivers to avoid any problems with air shipping as UPS (and other carriers) have an upper Gauss (magnetic field) limit. As Arendal Sound speakers and subwoofers are shipped world wide, we did not want them to be held at the airport terminals. We absolutely would not fit them with smaller motors than they deserve. We compromised nothing.

AIR FLOW VENTING

Air flow venting underneath the dust cap (vents in cone body) and spider (vents in frame) are added for two very important reasons. Air heated by the voice coil is forced away with each stroke of the cone diaphragm. This continuous exchange of air mitigates thermal compression and increases the woofer’s overall power handling capability. Second, the airflow relieves asymmetric compliance and noises (ie, distortion) due to non-linear compression and rarefaction of air typically trapped under the dust cap and spider. Typical, vented pole designs will be limited in effectiveness due to the lack of airflow volume – At the highest power and excursions, where free, smooth airflow is needed most, the pole vent alone is not sufficient.

The brain of Arendal Sound subwoofers
The brain of Arendal Sound subwoofers

The brain of Arendal Sound subwoofers, the Avalanche 500DSP and Avalanche 1000DSP, are built around a Texas Instrument’s 48-bit data path (with 28-bit filter coefficients) DSP engine, allowing virtually unlimited design flexibility with the assurance of no signal degradation along the way. Each amplifier’s transfer function, power output limiting and thermal protection are monitored to the millisecond and are customized for each individual drive unit and cabinet combination. The high efficiency Class D amplifier modules are based on a proven topology that has been continuously refined over the past 4 years. Excelling in transient response, high current output and very low distortion, they deliver the necessities for highly accurate, deep bass with output capabilities that drives and controls each 13.8” woofer to its fullest potential.

Perfectly matched, by design.

AVALANCHE PRE-AMP FEATURES

  • LED mode indicator (power on, standby, mute/protect).
  • Auto on/off (defeatable) on both RCA and XLR inputs.
  • 2 position user EQ modes for your taste:
    • EQ1
      • Frequency response is extended to the lowest octave offering more energy below 40Hz. This effect matches well to effects found in movies and often times is found work well for music tracks as well when more bass emphasis is desired.
      • EQ1 is recommended for larger rooms or if you lust for the extreme bass levels in smaller/larger rooms.
    • EQ2
      • Frequency rolls off gradually below 40Hz, counteracting the effects of “room gain” which raises in smaller rooms. The combined result can be a more accurate, balanced bass level across all octaves.
      • EQ2 is recommended for smaller rooms, especially for music.
  • Volume control with preset for home theater subwoofer gain calibration (reference level).
  • Continuously variable phase control from 0-180 degree.
  • 24db/Octave Linkwitz-Riley Low Pass Filter, variable from 40Hz-160Hz with bypass option for use with pre-processor’s internal bass management.
  • Subsonic protection filter in Subwoofer 3
  • Fully balanced differential XLR input & XLR pass- through output.
  • Soft start volume rise at power on.
  • Amp modules communicate with preamp protection circuit for status monitoring, shutdown & soft start functions.
  • Limiter continuously monitors bass energy content and within milliseconds will control the waveform to prevent any potential overdrive or unwanted distortions.
  • The measured latency is 3ms – Only adds 3ft/90cm in your pre-processor/AVR channel delays.

AVALANCHE POWER AMP FEATURES

  • Integrated high current switch-mode power supply with >90% efficiency.
  • Standby low power mode with <1W power consumption.
  • Self-oscillating PWM generation; less complex and more stable than many other Class D topologies with the benefit of reduced EMI.
  • High current output stage.
  • High damping factor.
  • Excellent transient response and low distortion across the entire power range.
  • Features 2x500W monoblock modules for the Avalanche 1000DSP amps, that are invert-cross-coupled to form a full bridge to more efficiently use the AC power and lowering distortion.
  • Features 1x500W for the Avalanche 500DSP amp.
  • Protection against over-current (and shorted outputs), over temp, over voltage and DC fault.
  • ETL, ROHS and CE certified.

ENCLOSURE TUNING

Vented vs. Sealed

ENCLOSURE TUNING

Vented vs. Sealed

Arendal Sound enclosures are produced in either vented or sealed alignments. Whether you go with a ported or vented speaker or subwoofer will impact how it sounds. Vented enclosures will be bigger than sealed enclosures to achieve the preferred frequency response while retaining high sound quality. For all our vented products we offer a port plug so in effect it behaves like a sealed enclosure for greater versatility.

SEALED BOX

All Arendal speakers start with an optimal, low Q sealed box designs. Low frequency performance is accurately damped delivering a tight impulse response – the time the driver takes to stop moving after the signal has passed is very short – and rolls off at the natural sealed box rate of 12dB/octave below the combined box and driver resonant frequency. This frequency (quoted as the -3dB point for the bass extension) is somewhat higher than a vented alignment, but the roll off below a vented speaker’s -3dB point happens at 24dB/octave. On paper the vented alignments -3dB point will look deeper, but the sealed speaker compensates with a more extension below roll-off.

It is worth bearing in mind that smaller rooms or speaker positions closer to a wall, tend to add 6-12dB of extra gain per octave with descending frequency below about 40Hz. This dovetails in nicely with the natural opposite delivered by the sealed alignment, to give a surprisingly extended and naturally flat, in-room response.

Thus, sealed boxes exhibit excellent, accurate sound reproduction, with a fast transient response and well damped impulse response. Their naturally flat in-room response and lack of ports, delivers minimal phase shifts, making them the easiest to integrate with a powered subwoofer.

VENTED BOX

The Monitor/Monitor S, Center/Center S and Tower/Tower S enclosures offer the ability to alternatively be used in a vented alignment. By removing the foam plugs inside the ports, low frequency -3dB point can be extended and given different bass characteristics. Damping and therefore impulse response are slightly less optimal than the sealed alignment, so the bass gains a slightly ‘fatter’ and warmer quality, with the extended response obviously delivering more bass output down to the ports tuning frequency. The other trade-off is that the port’s output adds a phase rotation at the bottom end, making addition of a subwoofer harder to integrate, but not impossible.

Larger rooms and/or speaker positions further from room boundaries, may value this extra natural output as they will be less supported than in a smaller room. Equally, some listeners may enjoy this extra output in smaller rooms to deliver truly earth shaking (if not entirely accurate!) bass.

Where Arendal Sound has been clever with the particularly bass proficient Tower, is the added flexibility of plugging combinations of the 3 ports and 2 ports for Tower S. With all ports open maximum bass output is guaranteed, but with a higher roll-off point. Obviously all ports plugged brings the Tower/Tower S back to a fully sealed alignment. The Tower/Tower S therefore delivers a choice of multiple roll-off, output and damping ‘tunes’ that will suit a wide variety of tastes, room acoustics and speaker placement.

In the case of the Monitor/Monitor S and Center/Center S, our recommendations are in line with the recommendations above with respect to port tuning, room type and positioning. Although remarkably bass proficient, it is envisaged that the Monitor/Monitor S and Center/Center S will typically be supported by a subwoofer for maximum bass extension and will therefore always perform at its optimum when run sealed in this situation.

ENGINEERING & DEVELOPMENT

How we do things

ENGINEERING & DEVELOPMENT

How we do things

THE GOAL

From the beginning, Arendal Sound products were developed with the mindset to recreate the original sonic event, with the highest level of accuracy. This requires a special consideration to balancing several factors:

Dynamics
Linearity
Distortion
Power handling
Frequency response
Polar characteristics

Experience has shown that each of these factors must be addressed for each design to fully achieve its sonic potential. If too much emphasis is placed on one factor, others will be compromised. There are many examples of loudspeaker designs that sound very good at modest levels, but when called upon to reproduce true dynamics the sound quality quickly disappears. Conversely, there are examples of high output speakers that can play quite loud and fill a room but are often characterized by sonic colorations that can range from displeasing to outright offensive – not very musical. The art and science behind Arendal Sound is to achieve all of the seductive nuances that make music so enjoyable and yet maintain composure with very demanding dynamics – this critical, but not easily achievable combination is the key.

EXTREME STRESS TESTING

Stress, or accelerated life testing, is a hallmark of all Arendal Sound designs. Each new design is required to pass a long list of difficult (if not insane) tests. From full out power testing repeated for days and in some cases for weeks, plus mechanical, thermal and vibration tests; all are designed to quickly identify and correct any potential problems during the design phase. If a component broke, we found out why and discarded it for something better. The result is a product that is as bulletproof as possible to ensure years of unbroken enjoyment.

CUSTOM MADE PARTS

Totally insane testing

CUSTOM MADE PARTS

Totally insane testing

CUSTOM MADE PARTS AND DEVELOPMENT PROCESS

Lofty goals require custom parts and special attention to details at each step in the path to product realization. Each driver was specially developed from the ground up, requiring much expensive and special tooling. No off-the-shelf drivers were worthy of satisfying all of our goals. Over 2 years in development, following a painstaking progression from theory to reality – each driver is first modeled using advanced FEA (Finite Element Analysis) techniques to meet mechanical, electromagnetic and acoustic goals.

Each component was specially evaluated and specified for each product. From the simplest screw, to crossover inductors, resistors and capacitors, the voice coil wire’s thermal characteristics and adhesives; all were selected with the goal of sonic accuracy driving all decisions. After the ground work, comes modeling, CAD and tooling. All speakers and subwoofers are then thoroughly analyzed using state of the art Klippel laser based measurement system, Audio Precision and Clio, alongside other electro-acoustic testing systems and proprietary (secret sauce) methods. Lastly, extensive listening tests to validates that the science meets the requirement of the art. Many refinements are made along the way. The final products are a culmination of experience, modeling, testing, and listening… Along with a lot of blood, sweat and tears and in the end, more than a bit of pride.

GRAPHS & DATA

Frequency Response

GRAPHS & DATA

Frequency Response

YOU WANT DATA?

You want to see the curves? Frequency, impedance and polar response charts for all products linked here.

All loudspeaker measurements are made in anechoic chamber, measured at 2.83v/1m. The subwoofers are measured at ground plane to get realistic frequency response, measured at 2.83v/1m.

Disclaimer: These measurements does not represent the actual response you will get in-room. In your room the speakers will be affected by room gain and surrounding objects/walls causing the bass levels to be elevated as well as the overall frequencies to be affected.

Click here to see Graphs & Data for all our products.

PREMIUM BUILD QUALITY

No plastic

PREMIUM BUILD QUALITY

No plastic

ROCK SOLID HDF CABINETS

Higher density and naturally better damped than MDF (Medium Density Fiberboard), using HDF (High Density Fiberboard) results in a sonically inert cabinet. HDF was also chosen because it can be machined much more precisely than MDF, which is especially important for precision critical areas like the two part HDF & Aluminum waveguide.

Arendal Sound products are using HDF thicknesses ranging from 18 to 50mm throughout the designs, with critical areas like driver mounting and cabinet bases being the thickest.

Internal bracing has been strategically placed to increase overall cabinet strength and limit unwanted panel vibrations that may cause audible colorations. Internal braces are CNC routed to shape to smooth internal airflow and minimize volume losses within the cabinet, whilst maintaining thickness at critical assembly joints.

The final detail for 1723 Tower, Monitor and Center, is to apply a butyl based differential mass damping layer to the inner faces of the cabinet, just to be sure we have damped out every last resonance in the large enclosures. Butyl is not added for 1723 S speakers as these have smaller enclosures and did not give any differences in testbench measuring or audible differences.

MAGNETIC METAL GRILLS

We are especially proud of our new exclusive and fully custom made grills. For all Arendal Sound speakers we have made a free flowing, perforated metal grill which does not affect sound quality. We have then wrapped it with a clean black cloth to tone down the visually hard look, whilst simultaneously damping out any residual vibrations.

In addition, we did not want plastic pins to add the grill, which will degrade the clean look of the cabinet with pin cups. Neodymium sub-surface magnets grip the metal grill with great force, preventing unwanted movement and vibration during high level playback. The grills have a rubber protection to ensure the cabinet is not damaged when you attach the grill and you will hear a nice ‘thump’ when you let them seat. Grilles on or off, our speakers look and sound great either way.

NO PLASTIC

Green Sound. Well, you may find a cable strap somewhere in plastic, but all components in Arendal Sound which affect the sound are built up from non-plastic parts, like our high grade aluminium back plates on subwoofers and speakers. Even our logo is in anodized aluminium.

RUBBER FEET

All subwoofers come with rigid rubber feet (M6 threads) which have a strong grip on the floor. You will not have a subwoofer walking around, even if that is impossible due to the sheer mass of our HDF cabinets which are “super quiet”. Put your hand on our speakers whilst they are playing and you will feel very, very little.

INTERNAL WIRING

Not your average zip cord. All products utilize high count multi-strand wire, braided together.  These were not done for looks, but chosen to produce the most consistent impedance possible and electrical current carrying capabilities. The benefit is very low insertion losses without the problems of “skin effect” caused by large diameter wires. This insures that each driver sees what the amplifier intended without additional colorations.

PREMIUM FINISHES

All Arendal Sound speakers come in four premium finishes;

Black Matte
Black Gloss
White Matte
White Gloss

To ensure the best and long lasting quality, all Arendal Sound speakers use up to 12 layers of paint, consisting of primers and polyurethane paint, hand finished. We use no vinyl, anywhere.

The finish is what you would expect from Hi-End products.

SPEAKER INPUT POSTS

Carefully crafted

SPEAKER INPUT POSTS

Carefully crafted

Not to be forgotten, the connection point of each speaker offers potential pitfalls for installation woes and signal degradations.

Each binding post is made from copper (not brass or other lower conductivity metals), then CNC machined into shape. After the machining process is completed, each component is polished to insure burr free, smooth function and clean cosmetics. The final step is Rhodium plating. Chosen for its excellent conductivity, corrosion resistance and hardness; all serve to protect the copper material and music signal carried within. Each post accepts commonly used wire terminations – banana, spade, pin and bare wire. Input jumpers, made from the same materials as the binding posts, create a simple bridge between inputs without any compromise in quality for use when Bi-wiring is not employed.

The exclusive terminal plate in brushed and anodized aluminum does not only have a beefy look but it also offers a, rigid resonance free performance. The reason for its size is the massive crossovers which are mounted on the back and they need all the space they can get. Mounting the crossovers directly on the plate gives the option for easy future upgrades…

SPIKES KIT

Effective and attractive solution

SPIKES KIT

Effective and attractive solution

There would be no point in the time and attention we’ve put into the massive engineering of Arendal Sounds speakers, if we then asked you to sit it on top of wobbly M6 or M8 spikes. We took a look at what spikes actually do and then applied straight-forward, uncompromising engineering to deliver an effective, attractive solution that doesn’t cost the earth.

Spikes have one job to do. Contrary to popular (marketing?) belief, they do not isolate the speaker and floor from each other. That could only be accomplished with a compliant mounting. No; they provide a solid and stable contact with the floor, locking the speaker rigidly in place. This is what we want, because we need every last detail from our custom built drivers moving air and not the cabinet.

The solution was simple and is included with the 1723 Tower, 1723 Tower S and the 1723 Stand as standard.

First, we engineered a thick aluminum bar that will not bend. The 1723 Tower weighs over 50kg and the 1723 Monitor on its dedicated 1723 Stand weighs over 40kg, before you start adding mass loading – and you can add a lot of mass to The Monitor Stand!

We made that bar long. Long enough to significantly extend the width of the speaker footprint, further aiding stability, and to give you plenty of Knuckle room for adjusting the spikes.

Then we looked at the spikes. We could see no reason why you should be asked to grovel around on the floor with spanners, tipping speakers up to get to the adjusters or locknuts underneath. So we engineered a large diameter conical spike in anodized black aluminum and top screw, all of which can be firmly tightened by hand from above and without having to tip the loudspeaker.

We have again avoided the use of plastics, so you can tighten the locking nuts as tightly as your hands will allow.

The Spike Kit is safe, simple, secure, attractive and very, very effective.

CONTENT OF SPIKES KIT

2 aluminum bars
4 aluminum spikes
4 rubber spikes
8 bar screws
4 metal discs

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