Subwoofer crossover points for Canton Movie 80CX 5.1 speaker system

by P Williams
(Wales, UK)

I have recently purchased the Canton Movie 80CX 5.1 speaker system and a Sony STR-DH810 AV receiver. Knowing nothing about subwoofer crossover points I ended up trying to research the subject using google.

I came across the following quote “Try aiming for a crossover point that's around 10Hz above the lowest frequency that your smallest speakers can reproduce without distortion.”

The Canton Movie 80CX speakers have the following specifications:

Frequency response (Hz) Satellites & Centre: 120 - 25,000
Frequency response (Hz) Subwoofer: 38 - 140 (adjustable)
Subwoofer: crossover (65 to 150Hz)

According to the crossover rule of thumb I should set the subwoofer crossover point to about 130Hz. I am confused as to why Canton would design the subwoofer to be capable of a crossover point considerably below 120Hz.

Would setting it to say 70Hz leave a hole in the sound between 70 & 120Hz? I am confused so can anyone help. The highest subwoofer crossover point setting is also 10Hz higher than its own maximum frequency response.

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Hi

Much of the information you have is about right.

“Try aiming for a crossover point that's around 10Hz above the lowest frequency that your smallest speakers can reproduce without distortion.”

Yes, that's a reasonable number to aim at.

"Would setting it to say 70Hz leave a hole in the sound between 70 & 120Hz?"

Yes, it would, so you don't want to do that.

The wide range of crossover frequencies for the sub is mainly due to the fact that speaker systems like these are designed to be inter-changeable and upgradable. For example, you could use the subwoofer with larger speakers in the future which would go below 120 Hz.

In fact, when setting up a system like this, you would not normally use the crossover control on the subwoofer itself - it is usually better to let the AV receiver control the crossover. Therefore, to start with, turn the subwoofer crossover control up as high as it can go - 140Hz.

Then, run the Digital Cinema Auto Calibration of the AV Receiver - page 35 of the manual. Most AV receivers have these auto calibration tools, and they are usually a good way to get a decent basic sound. Once it has done its job, you can tweak the odd setting to suit your taste.

The auto calibration will set a crossover frequency. When it has finished, go in and see what it is. If it's not quite right - say 100Hz - then you can manually change it to about 130 Hz. You can usually change the setting while you are playing some sound (music is usually better than a movie), so you can hear the difference it is making.

All the best.

Paul (Site Editor)

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