The UM18-22 is the 18” member of the Ultimax family from Dayton Audio. The Ultimax series features high-power handling, high excursion limits and dual voice coils. They build to move air and sometimes referred to as an audio bulldozer with a sports car’s finesse.

Highlights

• 18″ Woofer
• Over 50 millimetres of peak-to-peak excursion
• RMS power handling of 1000 watts
• Double spiders for stable excursions
• Dual voice coils for extended connection possibilities
• Air cooling through pole-piece and vents underneath the spider

Product details

Dayton Audio UM18-22 18″ Ultimax DVC Subwoofer 2 ohms Per Coil

The Ultimax Series from Dayton Audio is engineered to move air and produce low, clean and articulate bass. This 18” woofer is the largest member of Dayton Audio’s Ultimax family. It’s a large radiating surface area, and a massive excursion limit can move more than 6 litres of air on each peak-peak to stroke. These outstanding capabilities make it one of the most popular subwoofers from the SoundImports’ woofer category .

Other members from the Dayton Audio Ultimax series are the UM15-22 , UM12-22 and UM8-22 .

The UM18-22’s motor system is made up of powerful triple-stack ferrite magnets, dual voice coils that are each double wound with a diameter of 75 millimetres and a vented polepiece with dual shorting rings underneath and above the magnetic gap. Thanks to the large diameter voice coil and excessive venting through the pole piece and underneath the spider, there is excellent heat dissipation around the voice coils. The suspension consists of a “tall-boy” rubber surround and double spiders placed in a mirror configuration to reduce distortion caused by compliance asymmetry. The double (2 + 2 ohm) voice coils allow for stereo 2 ohms, mono 1 ohm or 4-ohm connections.

The electroacoustic parameters support a wide range of enclosure constructions. Place the UM18 in a compact 113-litre enclosure – like the Denovo Audio Knock-Down 113L Subwoofer Cabinet – and you will have an excellent closed-box performance with an F3 of around 28 Hz. In larger, vented enclosures, the UM18-22 is even capable of infrasonic frequencies; A 350 litre vented enclosure tuned to 15 Hz allows an F3 around 14 Hz. A more moderately sized 180 litres vented enclosure, tuned to 20 Hz, still gives an F3 of 18 Hz and is perfect for demanding home-theatre applications.

FAQ

Q: What enclosure should I build for the UM18-22?

A: That really depends on your needs and preferences. The UM18-22 is quite flexible and can be used in both sealed and vented applications. The type and size of the enclosure are always a compromise. You can take a look at the suggestions in the product text for some guideline. These are based on recommendations by the manufacturer and our own calculations. We encourage everyone to play around with simulation software like winISD to figure out what enclosure fits their needs.

Q: I am in doubt between the Ultimax series and the Reference Series from Dayton Audio. Which one should I settle with?

A: Both the Reference series and Ultimax are excellent subwoofers, and neither is a bad choice. They are both capable of low, loud and high-quality, low-frequency reproduction. The Ultimax is more on the extreme side, with higher power handling, a larger excursion limit and low impedance connection possibilities. The Reference series is somewhat more refined. We would recommend taking a look at your application. If you want seat shaking and window rambling experiences, the Ultimax is for you!