bottoming out? help

[trey4sports 10+ year member]

if i have my gain set correctly, and all wires connected and minimal voltage drop down to about 13 volts, but yet once my music is cranked up and i start to hear the subs kind of "miss" is that what is reffered to as bottom out? because im not having big voltage drop but i do get to a point where my subs (not my mids/highs) sound like they cut out, and they are moving quite a bit.

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[joetama 5,000+ posts]

Sounds like you DON'T have you gains set correctly...

 

[blackbonnie 5,000+ posts]

reset your gains

 

[BJ The Man 10+ year member]

if your using bass boost turn it off.

 

[trey4sports 10+ year member]

bass boost is off, gains were set with a DMM. so if this isnt bottoming out, whats it mean to bottom out?

 

[diminishedpower 10+ year member]

bottoming out you usually hear a loud clicking or physical pounding diff from the music, Depends on sub on exactly what it sounds like

 

[trey4sports 10+ year member]

almost like it has reached mech. limits?? i think thats what it is, my box is about 39HZ and when i play upper frequencys like some of jeezys stuff that peaks in the 40's i dont ahve a problem, but when i played chingy gettin it (i think thats what its called) it sounded like it would hit the top of the wave and kinda stop

 

[diminishedpower 10+ year member]

i cant remember the exact but with ported you will get that because after the tunign frequency the box losses control of the suspension. I cant remember the exact numbers ill let someone else state it but thats why you set your subsonic so many hertz under the tuning frequency.

 

[trey4sports 10+ year member]

so essentially this does sound like bottoming out? i wasnt sure i wanted to get some feedback

 

[diminishedpower 10+ year member]

depending on how low the song is going compared to your tuning its not bottoming out but just losing control of the suspension. but again im not there so i dont know.

 

[generalGOTCHA 10+ year member]

Does it sound like a like a hollow thump ?

Some songs arent liked by some woofers period, but from what your saying.. the subs sound good until you hit them with full power ? Or when a certain bass tone starts hittin ???

This is one of those grey areas where you have to be there and listening to it.

If I remember correctly, its when your subwoofer driver is hitting a frequency below tuning that this problem can occur. Your driver starts getting closer to free air resonance and at high power the driver over excurds and it loses its dampening effect when the motors inductance is forceing the cones mass to change cycles\new freq and you hear that "CLACK" sound which yes.. is the drivers mechanical limits. This can be a major factor in the box you built for it. Ive seen an issue where the volume of a box we built was to specs, but the inside chamber (forgot terms I think its called the baffle please someone correct me if I am wrong) where the back of the driver fires against and the air compresses before leaving out the port. Well it was to big in our case, we had to rebuild the box but we kept the same volume , and it never happened again. Its kind of hard to explain in words but I tried.

Anyhow if I am wrong on anything stated above, or I stated it not so accurate please correct me. We all learn from this place from those who know more.

 

[trey4sports 10+ year member]

awesome, what you described seems to fit the problem well. i thought 39 hz would be pretty high for a DD. but this i s just a temp setup my new woofers should be here pretty soon

 

[tcguy85 10+ year member]

your'e probably playing stuff below your tuning.

 

[diminishedpower 10+ year member]

all stuff i said but better explained lol, but ya for a good DD do 30-32 for good sq and spl, with that tuning you shouldnt start running into problems till 20 hertz or less and most songs dont go there

 

[helotaxi 5,000+ posts]

for a good DD do 30-32 for good sq and spl, with that tuning you shouldnt start running into problems till 20 hertz or less and most songs dont go there

That all depends on the sub and the exact design of the enclosure.

What the OP is describing sounds like the sub unloading below tuning. As the freq drops below tuning the air in the port gets out of phase with the cone and begins to cancel out the direct sound from the cone. The inertia of the air in the port also pushes the sub further than it would go under its own power. Run it too hard in this region and the sub could reach its mechanical limits and destroy itself. This could occur way below rated power by the way.