The Scale CD18SUB was not developed simply because we wanted another subwoofer in the Scale range. It was developed because our customers asked us for one.

By that time, the Scale CD10, CD12 and CD15 active loudspeakers had already become well established in Norway, with more than 1,000 units sold across the three models.

Customers using the CD series wanted a subwoofer that followed the same philosophy: professional performance, serious specifications, good sound and a price that remained within reach.

That request became the starting point for the CD18SUB, which was subsequently developed in Norway and Germany by Scale together with experienced German professional-audio engineers.

Since then, the CD18SUB itself has built a strong reputation in Norway, with sales approaching 100 units and consistently positive feedback from professional users.

In this article: Why we developed it · Development · Engineering approach · 18-inch driver · Amplifier & DSP · Cabinet & handling · Proven in Norway · Specifications · Applications · FAQ

Developed because our customers asked for it

The story behind the CD18SUB actually started with the success of the Scale CD loudspeaker series.

The CD10, CD12 and CD15 active loudspeakers had already become a well-established part of the Scale range in Norway, with more than 1,000 units sold across the three models.

As more customers began using the CD series for live sound, mobile PA, venues and installations, we repeatedly received the same request:

Could Scale develop a genuinely professional subwoofer to match the CD series — with professional specifications, strong sound quality and a price that remained accessible?

That customer demand became the starting point for the CD18SUB.

We did not want to develop just another inexpensive 18-inch active subwoofer. The objective was to create a system that could satisfy professional users in terms of output, low-frequency control, reliability and practical system integration while still following the value-focused philosophy that had made the CD series successful.

The result was the CD18SUB: a professional 18-inch active subwoofer developed specifically in response to what our existing customers were asking us for.

Developed in Norway and Germany

Once the concept had been established, development took place between Norway and Germany, with Scale working together with experienced German engineers specialising in professional audio system development.

The engineering team brought extensive experience from the wider professional-audio industry, including development work associated with some of the industry's major international brands.

The CD18SUB was not developed by simply selecting an existing amplifier module and combining it with an available 18-inch woofer.

The complete system was considered together: driver behaviour, cabinet volume, reflex-port geometry, amplification, DSP, cooling, mechanical construction and practical handling.

This complete-system approach is particularly important with a professional subwoofer because amplifier wattage alone tells only a small part of the story.

Engineering before branding

Professional loudspeaker pricing can vary dramatically even when two products appear relatively similar on a specification sheet.

Part of that difference comes from engineering and component quality. But part also comes from international distribution structures, marketing, brand positioning and the cost associated with maintaining large dealer networks.

Scale has always taken a more direct approach.

With the CD18SUB, the priority was to put the available development budget into the parts that actually influence performance: the woofer, motor structure, voice coil, amplifier, DSP, enclosure and acoustic design.

An interesting development occurred after the CD18SUB project had been completed. Approximately eight months later, a major European professional-audio manufacturer introduced an 18-inch active subwoofer in a similar performance and specification category, positioned at approximately €2,500.

We do not present the two products as identical. What was interesting to us was how closely the overall direction of the market followed the engineering approach already taken with the CD18SUB.

It confirmed that the concept behind the Scale system was positioned very much within the professional segment, even though Scale was able to offer it at a very different price level.

18-inch neodymium driver with a 4-inch voice coil

At the centre of the CD18SUB is a high-performance 18-inch neodymium woofer with a 4-inch voice coil.

The neodymium motor provides high magnetic flux and efficiency, while the large 4-inch voice coil supports high power handling and long excursion.

A ventilated magnet structure helps reduce power compression and distortion during sustained operation.

This becomes particularly important in professional use. A subwoofer may be operating for several hours during a concert, club night or event, and maintaining consistent output over time is just as important as producing a high SPL figure for a short demonstration.

Low-compression bass-reflex design

The woofer operates in a bass-reflex enclosure with an aerodynamically developed low-compression duct.

The purpose of the port design is not simply to generate more bass. Correct airflow and enclosure tuning help the system maintain a controlled low-frequency response as output increases.

The result is bass designed to remain defined and usable rather than becoming loose or uncontrolled when the system is driven harder.

900W RMS Class-D amplification

The CD18SUB uses a 900W RMS / 1800W digital Class-D amplifier.

Class-D amplification provides the efficiency required for a modern active subwoofer while keeping the amplifier section compact and reducing unnecessary heat generation.

The amplifier uses an aluminium heat sink together with a low-noise cooling fan to help maintain stable operating temperatures during extended professional use.

Integrated DSP for system setup

The integrated DSP gives the user practical control over how the subwoofer integrates with the rest of the PA system.

High-cut frequency can be selected at 80, 100, 120 or 150 Hz, with 100 Hz as the default setting.

The system also provides 0–180° phase adjustment and up to 16 ms of delay.

These controls are particularly useful when combining the CD18SUB with different top cabinets or when the physical position of the subwoofer requires timing adjustment.

The CD18SUB provides XLR input and parallel output connections, making it straightforward to integrate into professional PA systems and link additional equipment where required.

15 mm birch plywood and practical handling

A professional subwoofer must be designed for more than acoustic performance.

It has to be loaded into vehicles, carried across venues, positioned on stages, installed, removed and transported repeatedly.

The CD18SUB cabinet is constructed from 15 mm birch plywood and finished in black polyurea for a durable professional exterior.

The enclosure includes two recessed ergonomic carrying handles on each side, giving four handling positions in total.

At 37.5 kg, the CD18SUB is a substantial professional 18-inch system, but the four-handle arrangement makes two-person transport and positioning considerably easier.

M20 threaded pole mount

The top of the cabinet includes an integrated M20 threaded pole mount.

The threaded connection provides a secure mounting point for a compatible distance pole, allowing a full-range top cabinet to be positioned directly above the subwoofer.

This makes the CD18SUB particularly practical as the foundation of a compact mobile PA system.

Proven in the Norwegian market

Scale is still relatively unfamiliar to many professional-audio customers outside Norway.

That does not mean the CD18SUB is a new or untested product.

For many years, Scale's main market was Norway. The CD10, CD12 and CD15 built a substantial user base there, with more than 1,000 units sold across the three models.

The CD18SUB followed the same path.

Sales of the CD18SUB have approached 100 units in Norway — a strong result for a specialist professional PA subwoofer in a relatively small market.

More important than the number itself has been the feedback from customers.

The CD18SUB has been used in mobile PA systems, venues, clubs, live productions and installations, and the response from owners has been consistently positive.

Several customers have told us that the CD18SUB is among the best subwoofers they have used, especially when its performance is considered against its price.

For us, this real-world experience carries considerable weight. Specifications can tell you what a loudspeaker should be capable of. Years of customer use tell you much more about how the product actually performs.

Why is Scale less known outside Norway?

For many years, Scale operated primarily within the Norwegian market.

That naturally meant the products developed significantly stronger recognition in Norway than across the rest of Europe.

The brand therefore arrives in many European markets in an unusual position: the name may be unfamiliar, while several of the products already have years of practical professional use behind them.

With ScaleNordic now operating within the European Union, the products can finally reach a much wider European customer base.

The CD18SUB is one of the products we believe deserves considerably more attention.

Scale CD18SUB specifications at a glance

Where does the CD18SUB fit?

The CD18SUB is designed for professional sound reinforcement and can be used across a wide range of applications.

Typical uses include live music, DJs, clubs, theatres, houses of worship, event systems, fixed installations and mobile PA.

It was originally developed as the natural low-frequency extension for the Scale CD loudspeaker family, including the CD10, CD12 and CD15.

The adjustable high-cut, phase and delay controls also mean the CD18SUB can be integrated with many other professional top cabinets.

Why specifications alone do not tell the full story

It is tempting to compare active subwoofers by looking only at amplifier wattage.

In reality, the performance of a subwoofer is determined by the complete system.

The driver, magnetic motor, voice coil, excursion capability, enclosure volume, reflex tuning, airflow, amplifier, DSP, limiting and thermal management all affect what eventually comes out of the cabinet.

That is why the CD18SUB was developed as a complete loudspeaker system rather than as a collection of impressive numbers for a specification sheet.

The 900W RMS amplifier matters. The 4-inch voice coil matters. The neodymium motor matters. The cabinet design matters. The DSP matters.

But ultimately, what matters most is how all of those elements work together when the subwoofer is being used in a real PA system.

Frequently asked questions

Why was the Scale CD18SUB developed?

The CD18SUB was developed after customers using the Scale CD10, CD12 and CD15 repeatedly asked us for a professional subwoofer with strong specifications, good sound quality and an accessible price. More than 1,000 CD10, CD12 and CD15 loudspeakers had already been sold in Norway when the CD18SUB project was started.

Where was the Scale CD18SUB developed?

The CD18SUB was developed in Norway and Germany by Scale together with experienced German professional-audio engineers.

Is the Scale CD18SUB active or passive?

The CD18SUB is fully active. It contains its own 900W RMS / 1800W Class-D amplifier and integrated DSP, so no external power amplifier is required.

Does the CD18SUB have built-in DSP?

Yes. The built-in DSP provides adjustable 80, 100, 120 and 150 Hz high-cut settings, 0–180° phase adjustment and up to 16 ms of delay.

What type of woofer does it use?

The CD18SUB uses an 18-inch high-performance neodymium woofer with a 4-inch voice coil.

How loud is the CD18SUB?

The specified output is 128 dB continuous and 133 dB peak at 1 metre in free-field conditions.

Can I mount a top speaker above the subwoofer?

Yes. The top of the enclosure includes an M20 threaded mounting point for a compatible distance pole and top loudspeaker.

Is the CD18SUB suitable for mobile PA?

Yes. The cabinet is made from 15 mm birch plywood with a polyurea finish and includes two recessed handles on each side.

Why is Scale less well known outside Norway?

Scale was historically focused primarily on the Norwegian market. ScaleNordic is now making the range available to customers across Europe.

Does the CD18SUB already have a track record?

Yes. Sales have approached 100 units in Norway, and the product has been used in mobile PA systems, venues, live productions and installations over an extended period.