Pioneer sub sounds like its farting on low frequences

[thecoolnessrune]

I have had an HTiB for years now from Pioneer. It was a great starter kit, and lets face it, we dont all have 5k to blow on a home theatre. I would gladly just upgrade to a real sub, but now being a college student I have far less money available to me than I even did before.

My system is fine speaker-wise, I never have them up high enough to even use a quarter of their power most likely. (For kicks a few days ago I did take apart a speaker so I could see it and set the receiver to treat it as a full-range speaker... Little sucker can go ).

That's beside the point though. My problem has always been the subwoofer. It's an 8" subwoofer in a ported box made of pretty thick MDF (my guess if 1/2"). The amp is integrated. My problem is that at high volumes the subwoofer makes a horrid noise that sounds like something is rattling. Or farting... Something like that. I figure it can't all be port noise is it? It sounds like the amp components are vibrating inside or something.. I don't know how to open it because the MDF is glued together (I dont see any screws at all). Is there any way to quiet this thing down or am i just faced with the fact that I've reached the limitations of the sub and I just have to keep it at a lower volume?

EDIT: The video is linked here (Right click and Save)

Enjoy the farting!


EDIT 2 The biggest and perhaps last direct edit I'll do is this last video and set of pictures. I finally got up the nerve to take my subwoofer apart by removing the amp. I can't remove the darn grille because the STUPID pegs are glued into wood! *curses at the necessity of it even though he now can't get the friggen thing off* The subwoofer itself is the only thing remaining in the box and its still making that horrid noise. The subwoofer itself is glued together extremely tightly and i dont feel anything so much as vibrating in there. So here's a whole bunch of pics.

Cool! An Amplifier!
Wow.. Wish the heatsink on my comp was that big..
At least the caps on this thing are top notch..
The gassy little ah heck..
The gassy little ah heck's anus..
We're goin' in!
There's the mouth from the back.. The tonsils?
The large intestine in all its glory..
Stupid epoxied plastic pieces!

Well that's all the pictures I got. I also got a new longer vid! This time without one mention of the word "fart" for all you sensitive people out there. Plus now you can watch it at work without hearing a southern hick saying "fart" every couple of seconds, as I'm sure that would bring upon quite a burden of questions that would probably only bring about more questions than answers... But yeah, the video in all its gaseous glory can be found here (Again right click and save as).

Have fun everybody

 

[Nohr]

To have a look inside you'd have to remove the amp or the driver. The cabinets themselves aren't usually meant to be taken apart.

Honestly it just sounds like you're hitting the sub's limits. There are subwoofer options in the $150-$250 range that would probably do a much better job, no need to spend $5k!

 

[Rubycon]

A farting sub (my does that sound metaphysical!) in most cases is the result of an improperly selected crossover, too low of a high pass filter (HPF) causing the driver to become overworked prematurely. Once the voice coil begins to leave the gap it will sound bad. Vented enclosures should not be driven at frequencies below their vented resonance as excursion will reach x-max and eventually x-mech (the point where damage occurs to the voice coil former from striking the back plate of the magnet. ) Spiders and surrounds can also be damaged by this abuse.

 

[thecoolnessrune]

Originally posted by: Rubycon
A farting sub (my does that sound metaphysical!) in most cases is the result of an improperly selected crossover, too low of a high pass filter (HPF) causing the driver to become overworked prematurely. Once the voice coil begins to leave the gap it will sound bad. Vented enclosures should not be driven at frequencies below their vented resonance as excursion will reach x-max and eventually x-mech (the point where damage occurs to the voice coil former from striking the back plate of the magnet. ) Spiders and surrounds can also be damaged by this abuse.

Heh.. Well I've been doing it for the better part of 4 years so it must be one tough little booger

My High pass crossover is at 100Hz. That's as low as it will go and the recommended for my system. The other settings are 150Hz and 200Hz.

I dont know what the x-max of my sub is. Unfortunately I can find almost no existence of documentation about the driver. Just know that its an 8" driver powered by a "100 watt" amp (no idea if it can really do that, no more than I really believe the speakers are 100 watts at 8 ohms), shining a light in it looks like the driver has a foam surround, and judging by its resemblance to the rest of the Pioneer line I'd say the cone itself is IMPP. I have a digital camera with a mic so tomorrow I'll take a recording of the sounds its producing.

 

[thecoolnessrune]

As a continuation, I'll copy a PM I sent to Tiamat, as I'm open to all suggestions:

That's exactly the problem. The open areas are about the whole house. My room is very large but very narrow. (12x25). But I have a window-like area that goes into the computer room (10x10), an open doorway to the laundry room (5x10) and there is no door to my bedroom, just a large oak doorway that goes into a long hallway to the living room / kitchen 1 and then down another long hallway (30 feet in fact) that goes into a large kitchen and then that living room down a small hallway. The result is that my room is acoustically connected to the entire house simply because there's no door on my room (and since it is my parent's house, there never will be).

I'm going to an apartment this fall for college, so obviously I my subwoofer problem will be solved there.. I simply won't get one.. And I'll be worse off than before. But I still spend a lot of time here and would like a decent sub. If all the above wasn't bad enough my room is carpeted >_>

I'm just not sure what I could do about it. About $250-500 is all I could put out for a sub. But with me being in such an acoustically sucky area, I'm not sure I could put a subwoofer in the budget in and be happy with it. I would like to consider my-self an HT user, but the fact of the matter is that I use it to listen to music 99.5% of the time, and would like a subwoofer that can hit very hard while following a bass guitar. I listen to all forms of music. But I suppose to put it in simple terms I want it to hit hard to dance music, while being able to hit every low note with passion in Aerosmith's Don't Wanna Miss A Thing..

Am I just screwed?

 

[YOyoYOhowsDAjello]

You could get a pretty nice sub for less than $500.

Have you tried playing some test tones to see if it's particular frequencies or if it's below a certain point that it starts making the noises?

 

[thecoolnessrune]

Originally posted by: YOyoYOhowsDAjello
You could get a pretty nice sub for less than $500.

Have you tried playing some test tones to see if it's particular frequencies or if it's below a certain point that it starts making the noises?

Where could I get test tones to try? It seems to vary between the volume being too high or the frequency being bad.

For instance (and I'm sorry I only have pop music to test at the moment) If you take Ying Yang Twins and Wyclef Jean's "Dangerous" song, the song alternates between a low bass line, and a high bass line. It plays the high bass line just fine, but the low bass line just sounds horrid.

On Mary J. Blige's "Feel Like A Woman", the high part of the outro bass line sounds like absolute crap, but the low part feels solid and strong..

So maybe it is the x-max.. I dont think it's the x-mech because it's been doing this for 4 years, and while it sounds a little worse than it did before, it certainly isn't destroyed.

EDIT: And I know I could get a decent sub for $500, but the question is, can it do a decent job when my whole house is essentially my room >_>

 

[sdifox]

Originally posted by: thecoolnessrune

Originally posted by: YOyoYOhowsDAjello
You could get a pretty nice sub for less than $500.

Have you tried playing some test tones to see if it's particular frequencies or if it's below a certain point that it starts making the noises?

Where could I get test tones to try? It seems to vary between the volume being too high or the frequency being bad.

For instance (and I'm sorry I only have pop music to test at the moment) If you take Ying Yang Twins and Wyclef Jean's "Dangerous" song, the song alternates between a low bass line, and a high bass line. It plays the high bass line just fine, but the low bass line just sounds horrid.

On Mary J. Blige's "Feel Like A Woman", the high part of the outro bass line sounds like absolute crap, but the low part feels solid and strong..

So maybe it is the x-max.. I dont think it's the x-mech because it's been doing this for 4 years, and while it sounds a little worse than it did before, it certainly isn't destroyed.

EDIT: And I know I could get a decent sub for $500, but the question is, can it do a decent job when my whole house is essentially my room >_>

search for frequency sweep online, I am sure there is a wave file somewhere. sounds like you are overdriving the sub, turn it down before you get the ring stuck.

 

[YOyoYOhowsDAjello]

Originally posted by: sdifox

Originally posted by: thecoolnessrune

Originally posted by: YOyoYOhowsDAjello
You could get a pretty nice sub for less than $500.

Have you tried playing some test tones to see if it's particular frequencies or if it's below a certain point that it starts making the noises?

Where could I get test tones to try? It seems to vary between the volume being too high or the frequency being bad.

For instance (and I'm sorry I only have pop music to test at the moment) If you take Ying Yang Twins and Wyclef Jean's "Dangerous" song, the song alternates between a low bass line, and a high bass line. It plays the high bass line just fine, but the low bass line just sounds horrid.

On Mary J. Blige's "Feel Like A Woman", the high part of the outro bass line sounds like absolute crap, but the low part feels solid and strong..

So maybe it is the x-max.. I dont think it's the x-mech because it's been doing this for 4 years, and while it sounds a little worse than it did before, it certainly isn't destroyed.

EDIT: And I know I could get a decent sub for $500, but the question is, can it do a decent job when my whole house is essentially my room >_>

search for frequency sweep online, I am sure there is a wave file somewhere. sounds like you are overdriving the sub, turn it down before you get the ring stuck.

Here are some

http://www.realmofexcursion.com/

 

[thecoolnessrune]

Thanks Yo Yo. My googling skills were failing me. I'll try some of these tomorrow (my parents are asleep and as I said I have no door or anything, so for some reason one of the loudest spots in the house is their master bathroom Amazing how reflection works like that..

I was trying this in the mean time just for kicks and at this low volume its amazing how tight and precise the bass sounds. Maybe I really am just turning it up too loud :*( Still, I'll take vids tomorrow with some of these tones and you guys can hear the sound for yourself. But now I am convinced as well that I could be causing damage to the woofer.

EDIT: What exactly is the ring on the subwoofer btw and how would it get stuck? I've never noticed anything called a "ring" on a subwoofer. I thought about the only way to damage a subwoofer was to overheat the voicecoil or keep bashing it against the backstop with overexcursion (x-mech)

 

[thecoolnessrune]

Just a quick catch up before I must turn in for the night. I played a few test tones. This thing is definitely set for 40Hz. At that frequency even the lowest volume is too loud to play with my parents sleeping. 50Hz is also pretty loud. After that it starts to get quieter. I can hardly hear a 30Hz signal and 20Hz doesn't even come through. Obviously a very limited subwoofer.

I'll update more tomorrow guys. Thank you so much for your help and suggestions, this has been a question going on for 4 years now and I have no idea why i just decided that now would be a great time to get this resolved. Sure its not the answer I like to hear (that I may be damaging my sub) but at least its an answer and I can plan a course of action.

Good night all, and please keep suggestions coming for a nice replacement or diagnosis if you think something different is wrong.

 

[YOyoYOhowsDAjello]

Even if the sub did play 20Hz at the same dB level as 40Hz, it would sound a lot quieter to the human ear.
Here's some random graph I just googled that shows the sound level in dB at frequencies necessary to have the same perceived loudness.
http://hyperphysics.phy-astr.g...e/sound/eqloud.html#c1

I think you might just be expecting too much from the sub?
I have a bunch of suggestions for bang for the buck subs in the sticky thread.

 

[Rubycon]

It's an 8" driver? Nice midrange.

Yes it should definitely be HPF'd at port tuning frequency - most likely 40-55Hz for a box that size. It's easy to find the frequency IF you have a sweep generator. The point where the cone movement is nil with LOTS of air moving in the port is the tuning frequency.

Room effects won't make the speaker itself make strange noises however a room that's a "black hole" for bass will make you reach for the bass pot or lower frequency slider on an EQ. While boosting lower frequencies on a sealed box is generally considered OK, it should NOT be done on a vented box - especially below the tuned frequency! Distortion increases rapidly along with possible noises resembling gastrointestinal troubles.

 

[montypythizzle]

My BIC H100 is fine for my house, er, my room.

 

[sdifox]

Originally posted by: thecoolnessrune
Thanks Yo Yo. My googling skills were failing me. I'll try some of these tomorrow (my parents are asleep and as I said I have no door or anything, so for some reason one of the loudest spots in the house is their master bathroom Amazing how reflection works like that..

I was trying this in the mean time just for kicks and at this low volume its amazing how tight and precise the bass sounds. Maybe I really am just turning it up too loud :*( Still, I'll take vids tomorrow with some of these tones and you guys can hear the sound for yourself. But now I am convinced as well that I could be causing damage to the woofer.

EDIT: What exactly is the ring on the subwoofer btw and how would it get stuck? I've never noticed anything called a "ring" on a subwoofer. I thought about the only way to damage a subwoofer was to overheat the voicecoil or keep bashing it against the backstop with overexcursion (x-mech)

you won't see it it happens when you over drive the element past it's xmax... and it twists a little and gets stuck and not return to its neutral position.

 

[Soundmanred]

I think you might just be expecting too much from the sub?

BINGO.

 

[Muadib]

Originally posted by: Soundmanred

I think you might just be expecting too much from the sub?

BINGO.

Now that thecoolnessrune as come to that realization, what is he going to do about it?

 

[YOyoYOhowsDAjello]

Originally posted by: Muadib

Originally posted by: Soundmanred

I think you might just be expecting too much from the sub?

BINGO.

Now that thecoolnessrune as come to that realization, what is he going to do about it?

1. adjust expectations
2. get a low budget sub to hopefully improve the situation a bit but still keep expenses minimal ($150-ish?)
3. get a nicer sub that will hopefully keep him satisfied longer ($whatever he can afford)

 

[thecoolnessrune]

Yeah, I think I'm going to budget $500 into a decent sub to change things, especially since my room is so large. One problem I see is that a lot of subs in that price range seem to be downfiring. But my room is medium thickness carpet.. Wouldn't that kinda be like... firing into a pillow?

 

[Rubycon]

Originally posted by: thecoolnessrune
Yeah, I think I'm going to budget $500 into a decent sub to change things, especially since my room is so large. One problem I see is that a lot of subs in that price range seem to be downfiring. But my room is medium thickness carpet.. Wouldn't that kinda be like... firing into a pillow?

As long as distance is maintained between the baffle and the floor material - no. The feet do their job and you will still hear (and feel) sound from the box. Now if you remove the feet and lay it on the floor...you wind up with a five hundred dollar frog that sounds like it's been dining at the Taco Bell! :laugh:

 

[thecoolnessrune]

I finally put up a video of the woofer in the OP. If the word farting makes you laugh or pisses you off, dont watch cause I say it alot

 

[pennylane]

Originally posted by: thecoolnessrune
I finally put up a video of the woofer in the OP. If the word farting makes you laugh or pisses you off, dont watch cause I say it alot

That disclaimer made me lol. I have nothing else to add, except that I have a $200 sub (onix x-sub from av123) that I got because I live in an apartment building where neighbors can be annoyed easily. Still, it's been a great addition to my home theater and I can hear the low end even if I can't feel it so much.

 

[montypythizzle]

If it is farting give it more juice, you will clear up any noise it has now.

My sub farts too.

 

[thecoolnessrune]

The amp is built in. I can't give it any more juice than it has now. And you said in the description that its your mic making the noise.. Mine does it no matter what Hmm.. Perhaps I have blown it? I never really thought about that What's a blown subwoofer sound like?

 

[montypythizzle]

Originally posted by: thecoolnessrune
The amp is built in. I can't give it any more juice than it has now. And you said in the description that its your mic making the noise.. Mine does it no matter what Hmm.. Perhaps I have blown it? I never really thought about that What's a blown subwoofer sound like?

Your's does sound like it is blown. One too many abrupt explosions at high volumes. The Voice Coil former seems to have been malformed and is now scratching at the magnet.

Mine is just blowing massive amounts of air into the mic of the camera, your's is blown

May I interest you in buying a new sub? The only way it will sound good is if it is turned DOWN!! WAY down, but that will make no sense as your mains probably have no bass capabilities.

I know a friend's subwoofer like that. I suggest either a new driver from partsexpress.com.

If it is like another HTIB Pioneer system the sub is located on the back?? Easy to do a transfer.