So i was listening to my system today and i put my ear next to the box and i heard some sort of slapping noise. I know this cant be a good thing but who knows im a noob. I have a 12'' Q with the BP option being powered by a hifonics bxi1208d. I have the gain at half way and the sub sonic at 32 hz and the low pass at around 100 110. I have a down firing box, 2.5^3 ft tuned to 32 hz. Is the sub supposed to make this noise or what?

thanks for any help

I don't know a lot either and I don't know what the slapping noise is. But i do know that you should turn your sub sonic filter doooowwwn. If you have it at 32hz it means it is getting rid of frequencies below the tuning your box is at, which isn't good. Also i would turn your low pass down to around 80hz, the fi q is meant for low frequencies.

I thought you wanted your sub sonic set to where your box was tuned at....chit i guess i was wrong. Where do you think i should set it, i know its all on listening preference but i want a range.

thanks

how for down does your subsonic filter go?

15 hz

well from what i've heard, you should set your subsonic filter around 5-10hz below your tuned frequency. But i'd still definitely recommend turning your low pass down. I'm getting an Fi Q 12" and i'm setting my low pass down to 65hz, but that's just me

Do you have a new Q or an older one? Are your tinsel leads woven into the spider?

So i was listening to my system today and i put my ear next to the box and i heard some sort of slapping noise. I know this cant be a good thing but who knows im a noob. I have a 12'' Q with the BP option being powered by a hifonics bxi1208d. I have the gain at half way and the sub sonic at 32 hz and the low pass at around 100 110. I have a down firing box, 2.5^3 ft tuned to 32 hz. Is the sub supposed to make this noise or what?

thanks for any help

Do you have a picture of your box?

Edited May 15, 200916 yr by nmssd12

I have had my sub for maybe a month and a half maybe two so idk if its the new style or not...

but for the picture im going to have to wait till tomorrow to take it and set up a photobucket account.

What do you guys suggest for the low pass setting?

i wouldnt use a rule of thumb for setting subsonic filter. Since it is a safety device, what i would do is play a tone that is far below tuning that you are not really gonna achieve while listening to music.

So, if it's tuned to 32hz, turn subsonic ALL the way up and set your head unit to the maximum volume that you will ever play it at on a constant level.

Now, while the 20hz tone is playing, gradually turn the subsonic filter down watching the excursion depth of the sub. You have 2 choices hear. Limit the movement to it's Xmax(u will hear a big difference once it moves out of xmax, linear excursion) or Xmech which is maximum mechanical excursion. Once you find a good peak for your excursion, leave the filter there and never turn your volume up past where u set this at and NEVER boost any bass settings or increase the gain from this point on or you will have to retune it again.

OH, and be careful when doing this method.

Be sure you are not sending a dirty signal, clipped signal, etc and not hellaciously overpowering the sub with a gigantic amp when doing this because you are playing a full amplitude test tone for a while and is the quickest way to heat up a speaker.

sounds like a plan, thanks a lot guys!

could be the box driving apart and then slapping back togather.

could be the box driving apart and then slapping back togather.

That is what I was thinking.

To tell you the truth, i think that may be it because i would of heard this noise from before....

that brings me to another question though: Is a down firing box better than a standard ported box for my truck?

Ford F-150 Ext. Cab.

Try taking the sub out of the box and play it free air and see if the noise is still there. Just be careful, it won't handle very much power outside the enclosure.

If you have it at 32hz it means it is getting rid of frequencies below the tuning your box is at, which isn't good.

You should never be allowed to post any advice on here again.

The whole point of the SSF is to attenuate frequencies below tuning, to keep the driver from running into over-excursion. You set it so it begins cutting frequencies below tuning. In the case of a 4th order vented box, it can attenuate anywhere from 12-24db/octave below Fb and work pretty good.

But i do know that you should turn your sub sonic filter doooowwwn. If you have it at 32hz it means it is getting rid of frequencies below the tuning your box is at, which isn't good.

No.

Tell him to do that and he will break it for sure.

Shouldn't be having any noises...not really sure what to suggest outside of what others already have.

Play it free air on low volume / power..see if it makes the noise.

If you have it at 32hz it means it is getting rid of frequencies below the tuning your box is at, which isn't good.

You should never be allowed to post any advice on here again.

I almost fell out of my chair. . .

So i was playing it again yesterday just to see if i wasnt crazy and i heard it again. I will be taking the sub out of the box and inspecting what is wrong. it seems like it is only making the noise when it hits the lows so it could be the box slapping. I will keep you guys updated.

1) tinsel slap: older model FI had problems with extra long tinsels, so instead they shortened it and weaved it into the spiders.

2) extra wire from the terminals of the sub moving around

Ok well i hope this worked for pictures.....

If you cant tell on the one of the magnet, it is shifted. IDK if it was supposed to be like that or what. Please let me know what to do and what you guys think.

Edited May 18, 200916 yr by racerx86

If the magnet shifted a lot, the coil may be rubbing. But it would do it at all frequencies as long as the excursion is enough to put the coil where the shifted magnet is.

As people posted before it could be a the box, I had it happen to me last summer. I knew my favorite sub was blown till I had my tech look at it and he found the box seperation..

okay ill take the sub and put it in a different box and see if the noise continues.

Is the shifted magnets going to affect my sub in any way? Should i send it back in? I havent had it for long so i assume its still under warranty.