Cab farting / rig setup questions

[frankthetank727]

Hello all,

Here's what's going on. I've got this head Fender Bassman 300 | Musician's Friend and I right now I am running it into an 8 ohm Mesa Boogie 4x10 cab. I run the the Gain on 2, master no higher than 4.5, the Bass/Treble around 8, and have both the deep and bright settings enabled. I have the -6dB pad enabled as well.

I run two basses through this rig, both Carvins. I have a Carvin 6 string fretless that I run passive (even though it has an active 18v preamp) and a Carvin 4 string fretted. I notice an issue moreso with the 4 string. I get some farting on the speakers at certain frequencies and volumes, usually in the low registers. I haven't able to pinpoint if its 1) amp settings (too much bass, etc.) 2) the cab can't handle the load 3) too much extra gain from the bass and treble on my bass preamp or 4) something else in my chain

If its #2, would having another cab (thus making it 4 ohm load and having more speakers to push more air) allow me to drive the amp with less effort and take care of the farting issue? Because I already had to replace a blown speaker a few months ago and don't want to go through this again. In relation to #4, I have a pedalboard with a compressor, EQ, etc. I keep the EQ level low as not to overdrive the amp. Maybe my compressor settings are too harsh? Would high compression settings cause the spiking from the hot pickups to be overdriving the amp and cab? I have a hard playing style so maybe that combined with the overly hot active-ness of the pickups is causing this issue.

In the meantime I am going to try some various other settings and see what kind of luck I have. I Just am trying to decide if I am going to need another cab or a different cab. Any tips and suggestions are welcome.

Thanks and sorry for the long post!

 

[waltdogg]

Too much low end that you can't actually hear on the two extra low strings on your bass are killing your speakers. EQ out the lowest frequencies on the graphic EQ until the farting stops. Mainly 31.5Hz.

 

[B-string]

Keep in mind as frequencies get lower, so does speaker power handling and available amp power (headroom). What happens if you plug the bass (s) direct into the amp?

 

[scottfeldstein]

Wait, you have the low on "8"? That's zero-to-ten 8? Or do you mean eight o'clock? If it's zero-to-ten eight, that's part of your problem. Put the bass and treb at noon--straight up--and then turn off the "deep" switch. Then use your EQ to drop frequencies below 60hz. Make sure it's unity gain or just a hint louder than when it's off.

 

[Downunderwonder]

Meh, I don't know how the EQ works on those but it's fixed pointer with numbers on the knob so bass on 8 is probably your problem.

A fdeck HPF stops nasty low frequecies while allowing the bass knob free range.

 

[Eric_Allard]

On a fender tone stack, isn't "flat" approximately 2-10-2 (B-M-T)? Having the bass on 8 plus the deep switch engaged would result in a level of bass that would be punishing to just about any speaker.

 

[carl h.]

0-10 8 is too much with the deep button engaged. Set your graphic sliders to the mid settings, and your other tone knobs to 5.
A little goes a long way and you may not have the right speakers for producing such a bass heavy signal as are sending/blowing speakers with.

 

[frankthetank727]

Alright thanks everyone. Will try dialing back bass and fiddling with the other suggestions and see what happens. If this is in fact the problem but I still need the beefy low end, what would be a good type of cabinet setup to get in place of the 4x10?

I play pretty fast and sometimes technical metal, but we do have slower parts so I like to have the low end while also maintaining top end clarity. I'd love to hear other suggestions as far as cab's / low end speakers go, especially if I am going to have to dial back the bass with this current setup. Throw your best ideas at me. I'd even be willing to do a custom cab if that's what it takes because I kind of need the chunky low end. I don't want things to sound brittle.

 

[scottfeldstein]

maybe a fearful 1515/66

 

[esa372]

maybe a fearful 1515/66

...or 2.

Foz dares you!

 

[Bill Whitehurst]

Don't know what your budget is,
but, yeah a 1515/66 would more than do the job.

 

[Gearhead17]

Another identical 8 ohm Mesa Boogie 4x10 cab. More low end and volume IMMEDIATELY.

 

[BurningSkies]

Are you both cranking the bass up to 8 and using the graphic EQ?

 

[DavC]

if the "deep" button works similarly to the "loudness" button on some stereos ... it should used for a bas boost at lower volumes .. !?? and should be turned off at higher volumes ... as most have said , you're probably overloading the low end with stuff you can't even hear ..?? or if you want to really "feel the bass" get one of those tactile sub platforms that you can stand on .. !?

 

[Ben Noblit]

Wayyy too much bass. Some of it you probably aren't even hearing. Short solution, get an fdeck or something to protect your speakers. Long solution, go get an Acme or some variety of super 15 if you want that much low stuff.

 

[Jim Carr]

...I run... ...Bass/Treble around 8, and have both the deep and bright settings enabled...

...I get some farting... ...usually in the low registers...

...I already had to replace a blown speaker a few months ago... ...I have a pedalboard with a compressor, EQ, etc...

You are sending too much low end. I am surprised you have only blown 1 driver. The others could be half-toasted. If you are running distortion or overdrive on top of the EQ demands plus adding EQ from your pedal, I promise all the drivers in your cab—whatever cab or cabs you have—will die.

So. Roll the lows way back. Take off the deep and bright switches. Learn about midrange. That is where the tone is. Discover what levels of clean volume your speakers can produce. The fdeck HPF helps, if used correctly. Then abide by those limits if you start adding effects. Carry a spare.

 

[GMC]

Bass is a curious instrument in that it's fundamental isn't as important as it's 1st harmonic (at twice the frequency). So a low B of 30 hz, it's first fundamental (and significantly stronger) is twice the frequency (60hz). The 2nd harmonic is at 120hz. So I'd find a way to cut your bass EQ. Anything below 50hz isn't of any use to you. Most three band EQ's have a bass cut or boost control, the bass usually is set at a specific frequency and then ramps everything below that frequency. Which tend to be a little imprecise and lead bassists to think that "better bass" has the bass knob maxed out. Most of the useful bass frequencies (or lows) are in the 80-120hz region. Our mids tend to have a bigger impact in overall tone, and that's in the 200-1Khz region. Our treble is mostly in the 2-8Hhz range. So when a three band EQ has Bass, mid and treble controls...they can be misleading unless they are specifically for bass guitar. Hifi (or full range) Bass/Mid/Treble EQ's are set at 20hz, 1Khz and 20Khz. While the mids are useful (if a little high), the bass and treble controls will no next to nothing except add sub boom and high hiss. So we have to look for EQ's which are tailored to bass or in the case of a graphic Eq, intelligently choose frequencies which work for us on bass guitar. Have you seen the Thumpinator pedal? It heavily cuts all the lower sub frequencies which aren't helpful to our amps and speakers.

 

[WaldoNova]

Before replacing the cab get a Thumpinator or the fdeck hpf. Might be the lowest price solution. Also consider all of the eq suggestions already given.

 

[baxter_x]

Too much low end that you can't actually hear on the two extra low strings on your bass are killing your speakers. EQ out the lowest frequencies on the graphic EQ until the farting stops. Mainly 31.5Hz.

End of story

I used to have the same issue in the passt a broke a several speakers.
I decided to roll off the very deep lows. My entire rig sounded wayyy better, punchier and lows were cutting through like never before!
And abviously, no more fired speakers!!

 

[rolandm]

@GMC, Andy Lewis would strenuously object with your statement, and he has very good reasoning. Fundamentals actually are important, but due to the fact that we have to use a much higher amount of power to properly represent those lower frequencies, and because they are also fairly difficult to control at times, most people are fine to just go without them. I asked Andy why my LowB2 seemed to fart less when I was EQing out very specific frequencies with my GK BL600 (300 watts vs. the 500 recommended by Acme), but not with a 500 watt power amp.

Conventional wisdom is that most of the power is actually associated with the second harmonic, as opposed to the fundamental, in these lower frequencies. This would explain why decreasing the level of those higher frequencies would "free up" a surprising amount of power, which then could be used to reproduce the lowest fundamentals using your underpowered amp.

Some people, who in my opinion are not very bright, contend that because so much power is associated with the harmonics, as opposed to the fundamentals, that it's not necessary for the loudspeaker to reproduce the full range of the instrument. Of course, the proper relationship between the fundamentals and the harmonics should ideally be maintained regardless of the power ratios between the two, so I see that argument as sort of stupid.

Others opine that the human ear can't even hear a "Low B" note at all, which is both stupid and irrelevant. Anyone with a sine wave generator can disprove that silly idea in seconds!

Even if we couldn't hear those notes, we can and could still be able to "feel" them in a tactile sense, which is still an important part of the musical experience.