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Calum Audio Ltd

Sub of Doom

Sub of Doom

Regular price £985.00 GBP
Regular price Sale price £985.00 GBP
Sale Sold out
VAT included for the UK, no taxes charged for EU or US customers. You may be liable for import taxes, contact us if you're unsure. Shipping calculated at checkout.
Build Format

The Sub of Doom is an 18” horn loaded, port assisted subwoofer. Available with two driver options, a pair of ferrite BMS 18” drivers as the base offering, with an upgrade to dual neo 18 Sound 18” drivers for increased sensitivity, rms power handling and LF extension.

This box features quad Helmholtz resonators with purposefully turbulent airflow to aid in driver cooling and reduce power compression.

Measurements suggest a –3db point of 36hz in singles with the standard driver. In quads this drops to 30hz. With the premium driver, in singles this box ought to be at -3db at 34hz, in quads this drops to 28hz.

These cabinets / kits are built to order, please allow for a 8-10 week lead time. 

If you're purchasing a flatpack kit, please be sure to check the difficulty levels and advice in the dropdown sections below.

Features and Applications

This is a dedicated subwoofer cabinet. As with all horn loaded subwoofers, it benefits greatly from being used in multiples. We suggest this design really comes alive when you use 2+ together.

Flatpack kits include

  • All panels, cut from 18mm Birch plywood
  • All the screws you need
  • All the bolts and insert nuts you need
  • Gasket tape for the access hatch
  • Wadding
  • A pre-wired NL4 speakon dish, with a gasket
  • 8 metal bar handles with gaskets
  • 4 swivel casters, with heavy-duty internal mounting plates
  • Pre cut port tubing

Flatpack kit build difficulty

Expert. Cabinet building experience is necessary to be able to complete this build successfully. Reasonable build complexity, lots of individual parts potentially including multiple subassemblies. The order of assembly requires careful planning; there is only one way to build the kit. You need a drill / impact driver and glue. You will likely find clamps and a nail gun would be useful as well. Please do not order expert level kits if you are not confident you’ll be able to complete the build.

Acoustic Specifications

Exact acoustic specifications change depending on what driver you put in this cabinet.

We recommend the BMS 18S450 as a good standard option. This is what is in the Standard Loaded cabinet. You can expect a frequency response of 36hz - 200hz @ -3dB with single cabinets. With 4 cabinets, you can achieve 30hz @-6dB.

The 18 Sound 18NLW9601 is a great premium option. This is what is in the Premium Loaded cabinet. You can expect a frequency response of 34hz - 200hz @ -3dB with single cabinets. With 4 cabinets, you can achieve 28hz @-6dB.

Physical Specifications

  • 608mm x 1219mm x 1219mm HxWxD (without casters)
  • 4 cutout handles
  • 8 metal bar handles
  • 4 swivel casters with heavy duty internal metal mounts
  • Dual NL4 speakon
  • 18mm Birch plywood used throughout - 100% NON Russian plywood is used throughout our products, all timber can be traced back to the mill of origin.



This is a very large cabinet and has to be shipped on oversized pallets. Shipping outside of the UK is very expensive.

UK Shipping

This cabinet is available for purchase through this website for shipping within the UK.

EU Shipping

There are a growing number of countries that can purchase this cabinet directly with shipping via this webshop. We are happy to quote for shipping to anywhere in the EU, some countries are just a little more challenging than others, so require a manual quote to be generated. If you need a manual quote then please get in touch with us. Please brace yourself for this to be expensive, this is a very large cabinet.

Please be aware that you may be liable for import taxes and duties upon importing this item. If you have any questions, or your country isn't listed, please get in touch.

Global Shipping

This is one of the few cabinets that we will not ship globally due to the size.


Design credit for the Sub of Doom - Neman Horn goes to Scott Hinson of DIYRM. If you're a speaker nerd, it's well worth following his page on Facebook, it's full of excellent content.

The original design post can be found here.

Follow Scott's work here.

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