I hear it said but don't know what it means.

Anyone able to enlighten me.

Karl

Generally means your playing your subwoofer in the wrong size enclosure below recommended tuning. Most of the time the amp is driven to clipping by using to much bass boost, loudness function etc.

I'm sure somebody else will be able to answer better.

A lack of spring or pressure on a woofer by its enclosure, which can lead to out-of-control vibrating.

So would playing to loud below tuning cause it?

Yes.

See if this thread helps:

subwoofer unloading - SSA Car Audio Forum

Generally means your playing your subwoofer in the wrong size enclosure below recommended tuning. Most of the time the amp is driven to clipping by using to much bass boost, loudness function etc.

I'm sure somebody else will be able to answer better.

Clipping really has nothing to do with it.

Unloading is when the sub tries to move more than it should to produce sound, which can happen when it's played below tuning. With my box tuned @ 36hz, when I was going through songs once, I stopped on a 20hz test tone and it was the loudest to the ear I've ever heard it, it was over-excurting like crazy and while it sounded awesome it looked so bad for the sub, it looked like it was going to pop out of the box. Maybe a week later it blew a tinsel playing lows on music.

Read that other thread and wow. Full of loads of info, useful info.

If you were to tune to say 20Hz wouldn't you roll off higher up the range at say 30-35Hz, decreasing your spl in the higher range up to 60Hz?

Read that other thread and wow. Full of loads of info, useful info.

If you were to tune to say 20Hz wouldn't you roll off higher up the range at say 30-35Hz, decreasing your spl in the higher range up to 60Hz?

In a car audio enviroment yes!

The reason I ask is I'm looking at increasing my output at 20hz & 25hz with as little affect on 30Hz & 35hz.

I compete in propper droppers which is tested at the above frequencies and your peak then an average taken.

I'll be running a 6k 18" off of 2 sundown saz-3500s. I think it's called a MOAB in the states! It's branded up as a brand x audio BA series 18 in the uk.

Any ideas? It's a 4inch coil and nice strong motor so I'll be going slightly smaller on the enclosure side of things to help with the extra power.

Edited April 10, 201015 yr by B-chi

Do you know what your resonant frequency of your vehicle is?

No unfortunately not.

Really hard to recommend anything. Testing and more testing is about all you can do. Build a test box and use a removeable port and test some more until you find your sweet spot in the tuning.

Yeah was thinking along those lines. I'll start at 20Hz and work my way up.

I'm only going to have a couple of weeks testing before the first comp so was seeing if there's a quicker place to start. Not to worry.

Good luck! Let us know on your testing results.

Yeah will do.

You want to pound 20-25hz without losing 30-35hz, why don't you try a sealed box for a flat response? Buy a huge LMS driver like the Audiopulse or a bunch of Eclipse's, TC's, etc.

I understand I will loose higher up but would like to limit it. Scorng is based on an average so I'm looking for the best average. If that means higher 30-35 and low 20-25 then so be it.

Equipment is already bought so well get testing. Then I'll let you all know the outcomes.

I've got an 18 can't go any bigger in my boot I'm afraid lol.

Edited April 11, 201015 yr by B-chi

I would start with a tuning of 28 and go up with 2hz increases. (would be a lot faster to find the good tuning spot to hti the most at those freqeuncies.)