Reference

Reference · Tiles

TILEPASSIVE RADIATORMM

PR Excursion

A passive radiator can run out of travel while the powered cone is barely moving. This tile checks the radiator separately, against its own Xmax.
Shows
How far each passive radiator travels, peak and one way, in mm at each frequency, against its own Xmax.
Healthy when
The curve stays under the PR Xmax line at the power you will use, and the driver stays under its own Xmax on Excursion.
If it is not
More radiators, a radiator with more travel, or less power.

The tile#

PR Excursion

mm

  • One radiator9.5 mm at 33 Hz
  • Two radiators, same mass each6.1 mm at 37 Hz
  • One radiator, 25 W6.7 mm at 33 Hz
Passive radiator example at 50 W, half space, 1 m. Simulated when this page was built.

The single radiator peaks at 9.5 mm near 33.2 Hz at 50 W. The curve is peak, one-way travel per radiator. Open this example.

The dashed PR Xmax line belongs to the passive radiator, not the powered driver. Check Excursion alongside it. With passive radiators in both chambers of a bandpass box, the main curve is the larger front or rear travel at each frequency, and the limit lines identify their chamber roles.

Count and mass must be considered together#

In this comparison, two identical radiators with unchanged mass each peak at 6.1 mm near 37.4 Hz. Adding a radiator changes the tuning as well as the available area, so it is not a comparison at the same alignment.

ChangeWhat to check next
Increase Number of PRsRecheck the new tuning, the response shape and each radiator’s travel.
Increase Added mass (tuning)Tuning falls; recheck peak travel and the powered cone below tuning.
Choose a radiator with more Xmax or areaConfirm its mass, compliance and mounting space as well as travel.
Reduce powerBoth radiator and driver motion fall; compare the remaining SPL.

What to try#

TryWhat it changes
Use two radiatorsSet Number of PRs to 2. They share the work, so each travels less, and the tuning rises.
Mind the added massMore Added mass (tuning) tunes the box lower and can increase peak travel; recheck both the radiator and powered cone.
Less powerTravel follows the square root of power: half the power is about 0.7 times the excursion.

Ask your AI#

Ask your AI

Using 00 Simulator, check the driver and passive radiator excursion in my design at its current power. Preview a second identical radiator, report how tuning and peak travel change, and do not save the change yet.
or open it inClaudeChatGPT

Connect your assistant so it can open your designs.