Subwoofer magnet and toroidal transformers

[sjanand]

In the subwoofer I'm building, there are 2 X 300VA toroids planned as close as 3inches to the subwoofer magnet. My questions are:

1. Would the toroid demagnetize the subwoofer magnet in the long run?

2. Would the subwoofer magnet polarize the transformer to saturate?

Please comment.

Anand

[pjp]

Let me add another thing for you to worry about:
3. Will the heat from the transformer / amp spoil the speaker cone ?

[AndrewT]

Originally posted by pjp
Let me add another thing for you to worry about:
3. Will the heat from the transformer / amp spoil the speaker cone ?

The heat from the voice coil is more likely to be a cause of damage.

[peranders]

Originally posted by sjanand
In the subwoofer I'm building, there are 2 X 300VA toroids planned as close as 3inches to the subwoofer magnet. My questions are:

1. Would the toroid demagnetize the subwoofer magnet in the long run?

2. Would the subwoofer magnet polarize the transformer to saturate?

Please comment.

Anand

1 The transformer has a very low magnetic field around it = NO

2 Not likely with the distance but beware of it.

How big is the speaker element and how big is the enclosure? 600 VA in a small box?

[sjanand]

Peranders,

See http://picasaweb.google.com/anand.su...h/TheSubwoofer

There are two 12" drivers in push-pull config. Enclosure is completely sealed and is around 130 litres. SAF is bad -- Q is good -- around 0.85 measured roughly using SpeakerWorkshop.

I initially planned to plant the amp and transformers on the back panel. I'm now thinking of sqeezing them all into the pull-driver cavity. See snap 6.

--Anand

[bego2]

Nice sub.

[badman]

Toroids have good suppression of lateral fields. There is a significant field coming out the top and bottom of the toroid (like a column of flux centered around the hole).

Point this away from the drivers for best results.