Fearful 12/6 "farting" issues.. driving me mad !!SOLVED!!

[mrmakas]

Hi all!

I finally built my first Fearful 12/6 and have in the process run into some very interesting and frustrating experiences.

I have experiences with 4x10 cabs from Eden and GK that were top of the line and also i do sound engineering in the studio and live for a living. That said, i feel like a total fool

I first tested a Fearful 15/6 at someones rehearsal space with my own small Eden WT550 and was really shocked by the "distorted" sound coming out of the mid driver especially. It was farting out, but in a weird way. After this i posted online somewhere (probably here) and came to the conclusion that it had to have been the power amp giving too little juice to an 8ohm impedance cab. Hence the farting.. This made me put the whole building plans off for a while until now.

In the meantime i had bought an EBS Reidmar 750 (also only 350w@8ohm) and was looking for a smallish but powerful and great sounding cab -> the fearful 12/6. Supposed to be high sensitivity and take a lot of wattage if needed and give a great deal of substinence for it.

I first bought only the 3012LF and made the cab, not being able to afford the whole set with the alphalite and crossover parts etc due to other investments in gear. Expecting nothing from it i tried this setup (basically a FEarful 12 sub) and while being muffy, i kinda liked the punchyness and general feel of it. Once i had the money i figured i will finish the cab, and so i did.

This is where it gets really interesting... I hooked it up just like before, same bass, same settings etc. And the stupid farting sound was there again. To be honest i had a slight farting with just the lo driver before, but it was not as audible (bass distortion vs mid/hi). Now it is in your face. I was upset.

I figured it HAS to be the poweramp. So today i packed my gear in the car and drove to my shop where i have my FOH gear and i connected everything and tried the same system just powered by 1800w@8ohm. (ofc not blasting it to pieces) The biggest surprise: There was no noticeable difference between the EBS and the HUGE poweramp -> it was the cab then that farted...

Now i am at home. Dissapointed and almost ready to give up. Maybe i am expecting too much? Could it be a leakage between the mid and bass enclosure? or even in the bass enclosure itself (i have yet to properly seal the connection plate at the back that was fitted AFTER installing the mid driver. Now it is screwed tightly but not sealed with pl premium or silicone etc)? I figured a tiny leakage cannot affect such a huge farting sound, or can it?

What other problems could cause this? The farting funnily happened mostly around the area of and open A and E string. Tight and hard fingerstyle plucking cause real havoc here..

I would love for this to work, but i feel either
1. i expect too much,
2. both (the previously tested and my own fearful) have leakages (or other problems)
3. or then i am just a fool and cannot see the obvious........


HELP! please HELP!

 

[Stumbo]

@agedhorse or @Passinwind or a few other cab gurus might stop by and help you out.

You may have to get the cab scoped to hear where the distortion starts and stops.

Is your cab braced, glued and screwed properly?

Btw, under powering a cab is a myth.

 

[mmbongo]

Since two different Fearful cabs are both distorting the same way, I'd say you either don't like the sound of a dedicated mid or you need to add another cab to get enough output.

 

[mrmakas]

@agedhorse or @Passinwind or a few other cab gurus might stop by and help you out.

You may have to get the cab scoped to hear where the distortion starts and stops.

Is your cab braced, glued and screwed properly?

Btw, under powering a cab is a myth.

By scoped u mean the frequencies where it starts and stops or some kinda db reading? The cab is braced and glued. i removed screws after the glue had dried.. underpowering then would not cause any distortion?

 

[Old Garage-Bander]

Hi all!

I finally built my first Fearful 12/6 and have in the process run into some very interesting and frustrating experiences.

I have experiences with 4x10 cabs from Eden and GK that were top of the line and also i do sound engineering in the studio and live for a living. That said, i feel like a total fool

I first tested a Fearful 15/6 at someones rehearsal space with my own small Eden WT550 and was really shocked by the "distorted" sound coming out of the mid driver especially. It was farting out, but in a weird way. After this i posted online somewhere (probably here) and came to the conclusion that it had to have been the power amp giving too little juice to an 8ohm impedance cab. Hence the farting.. This made me put the whole building plans off for a while until now.

In the meantime i had bought an EBS Reidmar 750 (also only 350w@8ohm) and was looking for a smallish but powerful and great sounding cab -> the fearful 12/6. Supposed to be high sensitivity and take a lot of wattage if needed and give a great deal of substinence for it.

I first bought only the 3012LF and made the cab, not being able to afford the whole set with the alphalite and crossover parts etc due to other investments in gear. Expecting nothing from it i tried this setup (basically a FEarful 12 sub) and while being muffy, i kinda liked the punchyness and general feel of it. Once i had the money i figured i will finish the cab, and so i did.

This is where it gets really interesting... I hooked it up just like before, same bass, same settings etc. And the stupid farting sound was there again. To be honest i had a slight farting with just the lo driver before, but it was not as audible (bass distortion vs mid/hi). Now it is in your face. I was upset.

I figured it HAS to be the poweramp. So today i packed my gear in the car and drove to my shop where i have my FOH gear and i connected everything and tried the same system just powered by 1800w@8ohm. (ofc not blasting it to pieces) The biggest surprise: There was no noticeable difference between the EBS and the HUGE poweramp -> it was the cab then that farted...

Now i am at home. Dissapointed and almost ready to give up. Maybe i am expecting too much? Could it be a leakage between the mid and bass enclosure? or even in the bass enclosure itself (i have yet to properly seal the connection plate at the back that was fitted AFTER installing the mid driver. Now it is screwed tightly but not sealed with pl premium or silicone etc)? I figured a tiny leakage cannot affect such a huge farting sound, or can it?

What other problems could cause this? The farting funnily happened mostly around the area of and open A and E string. Tight and hard fingerstyle plucking cause real havoc here..

I would love for this to work, but i feel either
1. i expect too much,
2. both (the previously tested and my own fearful) have leakages (or other problems)
3. or then i am just a fool and cannot see the obvious........


HELP! please HELP!

Are you sure it's speaker farting and not a resonant vibration of some kind?

 

[chris_b]

Fearful farting? I've had that.

Scares the horses if you're not careful.

 

[Nighttrain1127]

Just for general info what are your amp settings? Too much bass boost can cause this too

 

[mmbongo]

Fearful farting? I've had that.

Scares the horses if you're not careful.

Better than Fearless farting I guess. I've ruined many a pair of tightie whities thanks to that.

 

[Downunderwonder]

I am curious how you went about reconstruction to add the mid chamber.

 

[mrmakas]

I just built it with the chamber to start with. it was just empty. My amp settings have a slight bass boost, but nothing too drastic. the basses EQ is flat.

 

[mrmakas]

and yes, i am pretty sure it is some kinds farting. ofc i cant be 100% certain.

 

[ctmullins]

Crossover? Maybe disconnect the woofer and run a sine sweep through it, and make sure the lows are filtered out for the mid driver.

 

[Passinwind]

@agedhorse or @Passinwind or a few other cab gurus might stop by and help you out.

You may have to get the cab scoped to hear where the distortion starts and stops.

Is your cab braced, glued and screwed properly?

Everything (handles, jack plates, drivers) needs to be 100% sealed, the tiniest leak can be surprising loud. The mid chamber needs to be stuffed per the plans, not just lined. Beyond that, the Greenboy forum has a much better track record than Talkbass for troubleshooting build problems, assuming that's what this is. That said, it's not altogether uncommon for some players to just hate the midrange character of these cabs, IMO, and IME. But to me farting is all about the bass, not midrange. And Passinwind knows farting, just sayin'.

 

[Wasnex]

Hi all!

I finally built my first Fearful 12/6 and have in the process run into some very interesting and frustrating experiences.

I have experiences with 4x10 cabs from Eden and GK that were top of the line and also i do sound engineering in the studio and live for a living. That said, i feel like a total fool

I first tested a Fearful 15/6 at someones rehearsal space with my own small Eden WT550 and was really shocked by the "distorted" sound coming out of the mid driver especially. It was farting out, but in a weird way. After this i posted online somewhere (probably here) and came to the conclusion that it had to have been the power amp giving too little juice to an 8ohm impedance cab. Hence the farting.. This made me put the whole building plans off for a while until now.

In the meantime i had bought an EBS Reidmar 750 (also only 350w@8ohm) and was looking for a smallish but powerful and great sounding cab -> the fearful 12/6. Supposed to be high sensitivity and take a lot of wattage if needed and give a great deal of substinence for it.

I first bought only the 3012LF and made the cab, not being able to afford the whole set with the alphalite and crossover parts etc due to other investments in gear. Expecting nothing from it i tried this setup (basically a FEarful 12 sub) and while being muffy, i kinda liked the punchyness and general feel of it. Once i had the money i figured i will finish the cab, and so i did.

This is where it gets really interesting... I hooked it up just like before, same bass, same settings etc. And the stupid farting sound was there again. To be honest i had a slight farting with just the lo driver before, but it was not as audible (bass distortion vs mid/hi). Now it is in your face. I was upset.

I figured it HAS to be the poweramp. So today i packed my gear in the car and drove to my shop where i have my FOH gear and i connected everything and tried the same system just powered by 1800w@8ohm. (ofc not blasting it to pieces) The biggest surprise: There was no noticeable difference between the EBS and the HUGE poweramp -> it was the cab then that farted...

Now i am at home. Dissapointed and almost ready to give up. Maybe i am expecting too much? Could it be a leakage between the mid and bass enclosure? or even in the bass enclosure itself (i have yet to properly seal the connection plate at the back that was fitted AFTER installing the mid driver. Now it is screwed tightly but not sealed with pl premium or silicone etc)? I figured a tiny leakage cannot affect such a huge farting sound, or can it?

What other problems could cause this? The farting funnily happened mostly around the area of and open A and E string. Tight and hard fingerstyle plucking cause real havoc here..

I would love for this to work, but i feel either
1. i expect too much,
2. both (the previously tested and my own fearful) have leakages (or other problems)
3. or then i am just a fool and cannot see the obvious........


HELP! please HELP!

Did you use the proper crossover modules? Some of what you describe sounds like the mid range is getting too much low end.

Another consideration. Fearful cabs generally like a lot of power to get loud. Is it possible you are simply over driving your amps? I.E. the distortion is the amp clipping.

 

[Coolhandjjl]

...The mid chamber needs to be stuffed per the plans, not just lined...

I just built it with the chamber to start with. it was just empty. My amp settings have a slight bass boost, but nothing too drastic. the basses EQ is flat.

Stuffed to the point of almost not being able to get the driver in.

If the chamber is indeed empty, that's probably the issue.

Did you use the proper crossover modules? Some of what you describe sounds like the mid range is getting too much low end.

That crossed my mind as well.

I've built three, and have used them with a Crest CA9. They all work fine.

Are you noticing this with multiple basses or just one? Is it an active bass?

 

[yodedude2]

air leak, crossover(s)...grilles?

 

[Munjibunga]

By scoped u mean the frequencies where it starts and stops or some kinda db reading? The cab is braced and glued. i removed screws after the glue had dried.. underpowering then would not cause any distortion?

"Underpowering" is a myth. Look elsewhere.

 

[10cc]

I've seen a GK MBF800 under power an F212. It was farting out the cab. Once an appropriately powered amp pushed the same cab all farts where ceased.

 

[Nickweissmusic]

My guess is, the full range cab isn’t necessarily going to give you the low mid oomph and apparent SPL you are used to hearing from typical bass cabs, so you are trying to do something the cab doesn’t want to do, and overdriving the speaker. Back in the day I had a fancy schmancy Tech folded 412 cabinet with tweeter, and I swear those 4 12s would start over excursion before I reached the apparent SPL of my single bag End 15 cabinet. Also, I can hear my newer bag end 15 with coaxial tweeter reach the end of its rope, before the 25 year old bag end 15 without tweeter does. At the end of the day, I think crossovers just aren’t perfect, and perhaps yours is defective, but like most things, sound is a game of compromises. It seems as though when you go for a full range, hi-fi sound, you can’t expect the same SPL as you do from a traditional woofer, in a similar sized cab (or sometimes a much larger one in the case of my old 412).

 

[BadExample]

Try disconnecting the crossover and wire straight to the 12. If that sounds good, the 12 is probably innocent and the crossover or mid is a problem.