Mixmatched Amp and Cabs Help!

[FenderMeBass]

Hello All

So I recently bought an AG700 because it can go down to 2.67 ohms. I have it plugged into 3 Aggie GS112's.

AG700 specs : Power Output: 700 watts @ 2.67 or 4 ohms, 350 watts @ 8 ohms

GS112 specs : 300 watts RMS

It is sounding farty. I've played two gigs. Putting the gain down as low as I can, putting down the output from DIbox and compressor, had limited results. I had to finish the gig.

Any suggestions ? Should I get rid of the AG700? Pick up different cabs?

 

[Al Kraft]

Have you played those three cabs together before? I ask because I am familiar with the head and cabs and farty would be the last word I would ever use to describe them. It's possible that one of the cabs is not wired the same as the others or you have a speaker cable that is wired backwards. This is where I would start my troubleshooting if I believed my bass, effects and instrument/patch cables were good.

The other obvious question is whether or not you have another amp/cab/combo set-up so you can test your bass, cable(s), and effects. If you have an active bass, I'd also check to be sure I had a fresh battery that was up to 9+ volts. I'm not 100% sure your problem and solution will surface immediately, but these are all likely culprits to check.

 

[FenderMeBass]

Hi Al
The cabs are good. I checked them all out. I've been playing 2 of them for years and love them. I upgraded to the Ag700 and added another 112 thinking it would be a dream, but unfortunately this is not the case. The cables are good, the pedals are good. My 9v bass sounded better than my 18v bass. But when driven, especially by lows, the farting sound comes back. I backed off the volume and bass and the sound was acceptable though muddy.
I miss my tecamp puma !

So you wouldnt think that the wattage difference here is something to think about it?

 

[WayneP]

What kind if EQ settings are you using? In my experience, “farty sound” is typically caused by the woofers being over-driven, either by too much power or excessive low-end boost.

It doesn’t appear that the AG 700 has a HPF, but a similar effect could be had by cutting the “bass” knob, which (according to the specs) has a turnover at 40 Hz. The GS112 isn’t doing anything down there anyway - I used to own one and took frequency response measurements of it, both in my living room and outside. It falls like a brick below 80 Hz. So cutting the bass knob some should get you some headroom.

If that doesn’t help, then it would seem to me that the AG 700 doesn’t like 2-ohm loads, the specs notwithstanding.

Regards,
Wayne A. Pflughaupt

Pedulla Club #45 Unique Arrangements of Hymns, P&W Standards, and Original Tunes
Administrator, Official Tobias Club #133
Administrator, Fretless Club #943
Big Cabs Club #23
My Basses
My Rig: Stage and FOH Friendly
Pedulla Club #45

 

[Al Kraft]

Hi Al
The cabs are good. I checked them all out. I've been playing 2 of them for years and love them. I upgraded to the Ag700 and added another 112 thinking it would be a dream, but unfortunately this is not the case. The cables are good, the pedals are good. My 9v bass sounded better than my 18v bass. But when driven, especially by lows, the farting sound comes back. I backed off the volume and bass and the sound was acceptable though muddy.
I miss my tecamp puma !

So you wouldnt think that the wattage difference here is something to think about it?

Does it sound okay with any combination of just one or two of thecabs? If so, then maybe the head is having trouble below 4 Ohms. I was pretty impressed with the AG700 and in general Aguiar heads have always delivered on their ratings IME. Hopefully others will have some ideas.

 

[crazyBassClown]

I upgraded to the Ag700 and added another 112 thinking it would be a dream, but unfortunately this is not the case.

Isolating the changes will help troubleshoot. Does the AG700 sound good with just the 2 cabs that previously sounded good? The previous amp with all 3 cabs if it can support the load or the new cab and one of the old ones if it can't?

 

[Old Garage-Bander]

Did you check relative polarity of the cabs to be sure they are all the same? As in the cones moving the same direction at the same time?

Try ONE of the two cabs that work well together with the third cab. See if that sounds OK. Then try the other original cab with the new one. If each combination of two sounds good then the polarity is probably correct on all three.
A deeper dive would be a battery test for polarity, or you can trace wiring from cab jack to speakers.
If you need to do that and aren't sure how to test polarity, like with a battery, let us know.

 

[dbsfgyd1]

Hello All

So I recently bought an AG700 because it can go down to 2.67 ohms. I have it plugged into 3 Aggie GS112's.

AG700 specs : Power Output: 700 watts @ 2.67 or 4 ohms, 350 watts @ 8 ohms

GS112 specs : 300 watts RMS

It is sounding farty. I've played two gigs. Putting the gain down as low as I can, putting down the output from DIbox and compressor, had limited results. I had to finish the gig.

Any suggestions ? Should I get rid of the AG700? Pick up different cabs?

maybe I missed it, but what is the ohm ratings on each cab? I’m assuming you are running these in series?

 

[shastaband]

maybe I missed it, but what is the ohm ratings on each cab? I’m assuming you are running these in series?

Going from one cab to the next cab to the next cab is NOT running them in series. These are parallel electrical connections because that’s how the jacks are wired (in every bass cabinet I’ve used or seen in the last 51 years).

 

[WayneP]

maybe I missed it, but what is the ohm ratings on each cab? I’m assuming you are running these in series?

The GS112 is an 8-ohm cabinet. At least the one I had was. So three of them would make for a nominal 2-ohm load.

Regards,
Wayne A. Pflughaupt

Pedulla Club #45 Unique Arrangements of Hymns, P&W Standards, and Original Tunes
Administrator, Official Tobias Club #133
Administrator, Fretless Club #943
Big Cabs Club #23
My Basses
My Rig: Stage and FOH Friendly
Pedulla Club #45

 

[crazyBassClown]

So three of them would make for a nominal 2-ohm load.

4 would make a 2 ohm load, 3 makes a 2.67 as per the OP. And there are definitely amps that differentiate between them.

 

[dbsfgyd1]

The GS112 is an 8-ohm cabinet. At least the one I had was. So three of them would make for a nominal 2-ohm load.

Regards,
Wayne A. Pflughaupt

Pedulla Club #45 Unique Arrangements of Hymns, P&W Standards, and Original Tunes
Administrator, Official Tobias Club #133
Administrator, Fretless Club #943
Big Cabs Club #23
My Basses
My Rig: Stage and FOH Friendly
Pedulla Club #45

The reason why I asked is the amp has a minimum load of more than 2 ohms if I remember correctly. Maybe the amp was unstable running lower than the safety rating.

I dunno, I didn’t engineer it.

 

[JeezyMcNuggles]

Hi Al
The cabs are good. I checked them all out. I've been playing 2 of them for years and love them. I upgraded to the Ag700 and added another 112 thinking it would be a dream, but unfortunately this is not the case. The cables are good, the pedals are good. My 9v bass sounded better than my 18v bass. But when driven, especially by lows, the farting sound comes back. I backed off the volume and bass and the sound was acceptable though muddy.
I miss my tecamp puma !

So you wouldnt think that the wattage difference here is something to think about it?

Hook them all together, then run your instrument cable out one of them. Touch a 9v to it. Positive to the tip, negative to the sleeve. They move. If one moves inward, instead of outward, pull the speaker out, and swap the leads. Check it again.

If everything's good on the battery test, use a compressor, or simply lower your bass knob.

 

[PotsdamBass8]

Really good suggestions here. I’ll add, what kind of volume are you expecting and getting? 3 GS112 should be able to handle a good amount of volume, but there are plenty of people who require more volume than they can provide. That’s not the fault of the cab. It’s hard to quantify the volume, but let’s put it this way: a 3rd cab will be a little louder than the two that you’re used to gigging. Are you expecting significantly more than in the past, or is it close to what volume you were getting with the two?

 

[jellymax]

start with the aggy and 1 cab. if there is a problem, try a different cord, then a different bass.
if no problem then;
do the 9v volt batt test on each cab. if ok, then 9v test on each speaker cable.
if ok then;
try 2 cabs. if ok, then try 3 cabs. if not ok with 3 8 ohm cabs, then your amp is likely the culprit.
some amps don't like 2.67 ohms.

 

[Rip Van Dan]

Hello All

So I recently bought an AG700 because it can go down to 2.67 ohms. I have it plugged into 3 Aggie GS112's.

AG700 specs : Power Output: 700 watts @ 2.67 or 4 ohms, 350 watts @ 8 ohms

GS112 specs : 300 watts RMS

It is sounding farty. I've played two gigs. Putting the gain down as low as I can, putting down the output from DIbox and compressor, had limited results. I had to finish the gig.

Any suggestions ? Should I get rid of the AG700? Pick up different cabs?

I could see that if you have your Bass EQ dimed or way the hell up on your amp. What are your EQ settings?

 

[Rip Van Dan]

The reason why I asked is the amp has a minimum load of more than 2 ohms if I remember correctly. Maybe the amp was unstable running lower than the safety rating.

I dunno, I didn’t engineer it.

Three 8Ω cabs would put a 2.67Ω load on the amp, which the amp can supposedly handle. It would take a fourth 8Ω cab to push it down to a 2Ω load...unless of course, there's a problem with the amp.

 

[FenderMeBass]

What kind if EQ settings are you using?

---->eq is essentially flat with treble cut to 11:30 and bass along with mid boosted to 12:30 (meaning halfway to 1 o clock)

It doesn’t appear that the AG 700 has a HPF, --> whats that?

but a similar effect could be had by cutting the “bass” knob, which (according to the specs) has a turnover at 40 Hz. --> turnover?

The GS112 isn’t doing anything down there anyway - I used to own one and took frequency response measurements of it, both in my living room and outside. It falls like a brick below 80 Hz. So cutting the bass knob some should get you some headroom.

--> does this mean the 112 doesnt have very much super low freq ability?
thanks!

 

[FenderMeBass]

start with the aggy and 1 cab. if there is a problem, try a different cord, then a different bass.
if no problem then;
do the 9v volt batt test on each cab. if ok, then 9v test on each speaker cable.
if ok then;
try 2 cabs. if ok, then try 3 cabs. if not ok with 3 8 ohm cabs, then your amp is likely the culprit.
some amps don't like 2.67 ohms.

when you say 9v battery test you mean with a bass? or with a meter?

thanks ?

 

[FenderMeBass]

Did you check relative polarity of the cabs to be sure they are all the same? As in the cones moving the same direction at the same time?

Try ONE of the two cabs that work well together with the third cab. See if that sounds OK. Then try the other original cab with the new one. If each combination of two sounds good then the polarity is probably correct on all three.
A deeper dive would be a battery test for polarity, or you can trace wiring from cab jack to speakers.
If you need to do that and aren't sure how to test polarity, like with a battery, let us know.

definitely in over my head here,

the cabs look new and stock