4x12 Cab Question

[tpwelie34]

Hey guys, I've just recently purchased a 4x12 cab and a head for the first time and have a question.

When I play through it, the sound sounds much better if I walk towards the left side of my cab. Here, the low frequencies sound substantially more than if I were directly in front of or on the right side of the cab.

If I play and stand in front of the cab, it sounds sort of weaker as it is had to hear the low frequencies.

The right side of the cab is like the front side although there are more low frequencies but not as much as the left side.

Do you guys think there is a problem with my cab? Is it an EQ issue? Maybe its an issue with the room?

 

[94Tremoverb]

What brand and model of cab is it? (Some have internal switching that can cause trouble.)

Did you buy it new? (If not, it could have been repaired and be wired incorrectly - actually it's just possible even if it's new!)

It sounds like you may have a speaker phase issue or one (or more) not working properly - I think it would be unlikely that the room could make as much difference as that, although you could try moving the cab. It doesn't sound likely to be an EQ issue either as that would affect the whole cab.

 

[tpwelie34]

What brand and model of cab is it? (Some have internal switching that can cause trouble.)

Did you buy it new? (If not, it could have been repaired and be wired incorrectly - actually it's just possible even if it's new!)

It sounds like you may have a speaker phase issue or one (or more) not working properly - I think it would be unlikely that the room could make as much difference as that, although you could try moving the cab. It doesn't sound likely to be an EQ issue either as that would affect the whole cab.

I bought it used. Is it supposed to sound the same if I stood in front of/to the left/right ? Also, I connected it to my head from the 8ohm jack of the cab to the 8ohm jack of the head. Thats correct, right?

 

[espboogie123]

No they are not suppose to sound the same. If you are standing in front of the amp, you will be blasted with high frequencies that will overwhelm the low end. Standing from the side will eliminate those high frequencies being blasted to your ears thus enhancing the low end. That's the problem with most 4x12 cabs. A guitarist at a show with high amp volume will kill the people standing directly in front of the 4x12, but a simple two feet step to the left or right can make a drastic change in volume/frequencies. Weber Speakers Beam Blockers can help with this problem.

 

[94Tremoverb]

Is it a Mesa cab?

Yes, 4x12"s are very directional, but it only applies to the high frequencies. The low frequency response should be roughly similar both in front and off axis, and in particular it should not be different when standing on opposite sides of the cab, or weaker when directly in front. That makes me think it's some sort of phase or wiring issue.

How to test phase: plug a speaker cable into the mono input, but not into the amp. Get a 9V PP3 battery and hold it to the loose end of the cable so the 'crown' is touching the sleeve of the plug, and then tilt it so the 'stud' touches the tip. As the stud makes contact you should see (even through grille cloth) all four speaker cones move forward, by the same amount. Don't hold it on for longer than necessary to see the cones move - repeat on and off if you're not sure or can't see all the speakers at the same time. If any of the speakers move in the wrong direction, or not much, there is a problem with the cab wiring.

 

[tpwelie34]

Like espboogie said, am I just not hearing that much of the low frquencies because I am being overwhelmed by high frequencies when standing directly in front of the cab?

Do 2x12 cabs have this problem?

 

[YellowJacket]

In general, close back cabs tend to be very directional. Even something like a Thiele with the front vent is also directional. If you want something more 3D and open, a 3/4 back, half back, or open back will be much moreso that way. The downside with an open back is that you lose the punch and thump.

Speaker selection is also a factor too. With any cab, v30s tend to be very VERY shrill sounding, especially at low volumes. Mixing them with c90s will definitely mitigate the highs quite a bit. It flattens things out and gives a more even response. I hear you though, sensitive ears don't do well with high SPLs. I run into that problem. I literally can't handle the highs that come out of a high power tube amp. This is what ear plugs are for!

 

[tpwelie34]

So my situation is normal? I bought this used cab from a female that has owned it for roughly 4-5 years and has taken it out on one tour but it still is in excellent condition so buying it for 400 was a steal for me.

 

[YellowJacket]

It possibly is normal. Definitely be aware of resonance frequencies in a room where you are playing. You would not believe how much a room colours sound. What annoys you might be how sound is reflecting off of flat surfaces while you play, but it might also be resonance frequencies in the cab itself. I have noticed for sure that the sound I hear in a room is always different than the sound I get when micing and recording.

 

[tpwelie34]

So what can I do to figure out if my cab is working as intended?

 

[YellowJacket]

Quick and dirty solution?

Take it to a music store and AB it against a new one!

 

[94Tremoverb]

So what can I do to figure out if my cab is working as intended?

How to test phase: plug a speaker cable into the mono input, but not into the amp. Get a 9V PP3 battery and hold it to the loose end of the cable so the 'crown' is touching the sleeve of the plug, and then tilt it so the 'stud' touches the tip. As the stud makes contact you should see (even through grille cloth) all four speaker cones move forward, by the same amount. Don't hold it on for longer than necessary to see the cones move - repeat on and off if you're not sure or can't see all the speakers at the same time. If any of the speakers move in the wrong direction, or not much, there is a problem with the cab wiring.

Use a flashlight to look through the grille cloth if you can't see clearly. If this is sounding like you need more than two hands, get someone to help!

If the speaker cones are all moving correctly by the same amount and in the same direction, it's unlikely there's anything wrong with the cab and it's just the room or the directionality.

Is this a Mesa cab?

Mesa and some others (eg modern Marshall) have switching options on the back of the cab. These rely on contact points in the jacks to pass the current when the cab is in mono - if the cab hasn't been used for a while you can get corrosion in the contacts which can stop some of the speakers working properly, or if the cable has been tugged sideways when plugged in it can bend the jack contacts and do the same. Either is possible if you bought the cab used.

 

[screamingdaisy]

What brand and model of cab is it? (Some have internal switching that can cause trouble.)

Is it a Mesa cab?

Is this a Mesa cab?

Do you ever get the feeling you're being ignored?

 

[tpwelie34]

Yup, its a mesa cab.

 

[boogieman60]

+100 on the battery test...if the speakers are in phase when you touch the barrel of the plug (-) to the tip of the plug (+) and battery ,the cones should move forward. Great test...not a bad idea to perform on all new equipment..people are only human... :?