Category Archives: dj-blog

the box pro DSP 18 Sub

the box pro DSP 18 Sub review

New for 2019 season.

I now have a great new pair of 18″ subwoofers replacing my trysty Alto TSSUB15. Whilst the new aub’s are larger and heavier than my old ones, they are more powerful and the bass goes deaper. This is great if you’r a fan of R&B, beyonce,ย Flo Rida – Low, or any other song where you want some rumble ๐Ÿ™‚

  • Ply construction, so is strong and lightweight
  • Great power to weight ration of only 35kg
  • With:18″ driver at 800W RMS,ย  which is more than enough for any event.
  • Maximum output level: 128 dB – Peak 131 dB

Some more technical imagesย “the box pro”ย  “DSP 18” breakdown including poweramp module and driver

The 18″ driver has a 120oz magne and has a cast frame!

JAM18A-SUB is the power amplifier module. Don’t know much about this class-d 800w module.

Alto TS215 Active speaker

A quick servicing of my trusty Alto TS215 main speakers. Been using these for the last year and I can say that I am very impressed with the quality of sound, weight and overall performance of the Alto TS215.

On of mins started rattling where the amp plate is screwed to the speaker case, so I thought i’d take some photo’s of the insides since I can’t find any on the web.

These are marketed as 1100 watt speakers. From my experience and inspecting the units I believe that the true RMS wattage of the Alto TS215 is about 275w RMS.

Firstly looking at the neodymium compression driver which has a heat sink. This is lovely and clear and never distorts. The compression driver is a fairly compact unit and units of this size generally handle from 50w RMS.

With the extra heat sink (as seen below),ย  i’d guess it will handle 75w RMS.ย HG00602

Below is the amplifier module.ย ย ย (21) UT1609112933344 B160802596ย HK16961

(21) UT1609112933344

Read of 15″ woofer

Front with grill removed

15″ woofer side on view

Woofer part code HK17413 1607 – 4 Ohm subwoofer

Given the weight and the fact that it has a ferrite magnet makes it easy to estimate the power rating since it’s related to the size of the magnet.

The Alto TS215 woofer can handle 200w RMS. This can be confirmed by connecting it to an external amplifier whilst it’s in it’s enclosure.


Overall the TS215 is an excellent speaker for 275w RMS. I wish manufactures would go back to stating the true RMS wattage of their speakers as it would make it easier to compare. I notice that Behringer also over-inflate their ratings to similar levels.

In comparison to the Wharfedale LX15 (400w RMS) these are almost as good. When you are a mobile DJ and consider the weight of these vs using an external amplifier and two Wharfedales, the extra reliability of using two active speakers vs a single amp. The Altos are a winner every time.