Greenboy basic 15 cab farting out on lower notes?

[Cutty]

Hi Guys,
I had this greenboy cab built for me it's fitted witha Faitel PR15 400w,which i bought new,but on the lower bass notes it farts out,do you think it may be the porting,or is it possible the speaker is bad?the cab was built with the standard port length so i wonder if anyone has had this problem too,Thanks,Cutty.(i have used it with different amps so it's not that)

 

[themickster]

Try lowering the bass and mids on one of your heads. If that doesn't work, try lowering the volume.

 

[Marko 1]

(i have used it with different amps so it's not that)

If nothing is wrong with any of your gear, it sounds like you're pushing lows pretty hard.

What's your EQ look like and how much power are you using?

 

[Cutty]

I'm using a Ashdown CTM100 all tube amp all eq is flat,and the amp can go pretty loud but this is just in the house when i'm testing it,so not too loud.Thanks.

 

[OldogNewTrick]

can you give us the inside dimensions of the enclosure, together with the port diameter and length.
That would be the only way to simulate the enclosure in order to find out it's xmax limited power.
IIRC it should be app. 80 ltrs tuned to around 50Hz, which should give you solid power handling for a 100W tube amp.
Then on the other hand, there is knowing and there is guessing......

*knowing /simulating driver/enclosure needs the above data.

 

[themickster]

Have you spoken to the builder about it? There might be a bad connection.

 

[Snert]

but on the lower bass notes it farts out

B or E string?

 

[agedhorse]

Might the amp simply be running out of power at low frequencies?

Try another amp first.

 

[Killing Floor]

Where do you set your HPF?

 

[eniac]

I'm using a Ashdown CTM100 all tube amp all eq is flat,and the amp can go pretty loud but this is just in the house when i'm testing it,so not too loud.Thanks.

Cutty, when you say the EQ is "flat", do you mean true flat, or all tone controls at noon?

 

[Arjank]

Might the amp simply be running out of power at low frequencies?

Try another amp first.

This

Since you (Cutty) already mentioned that this happens at a relative low volume I suspect it's not the PR15 that's running out of breath.
Can you give an indication of the cone movement? If it's just a few mm's then I'm pretty sure it's not the PR15.

 

[Cutty]

Cutty, when you say the EQ is "flat", do you mean true flat, or all tone controls at noon?

Yes thats correct,all at noon.

 

[Cutty]

If nothing is wrong with any of your gear, it sounds like you're pushing lows pretty hard.

What's your EQ look like and how much power are you using?

All EQ are at noon,preamp at 9o'clock,so pretty low,and volume adjusted with the master volume control.

 

[Cutty]

Try lowering the bass and mids on one of your heads. If that doesn't work, try lowering the volume.

Ok i will try this.

 

[Cutty]

can you give us the inside dimensions of the enclosure, together with the port diameter and length.
That would be the only way to simulate the enclosure in order to find out it's xmax limited power.
IIRC it should be app. 80 ltrs tuned to around 50Hz, which should give you solid power handling for a 100W tube amp.
Then on the other hand, there is knowing and there is guessing......

*knowing /simulating driver/enclosure needs the above data.

I will have to have a word with the builder of the cab but it's built with the greenboy specs,i believe the ports are 8"in length.

 

[Cutty]

This

Since you (Cutty) already mentioned that this happens at a relative low volume I suspect it's not the PR15 that's running out of breath.
Can you give an indication of the cone movement? If it's just a few mm's then I'm pretty sure it's not the PR15.

Yes it is only about 2mm.

 

[Arjank]

Yes it is only about 2mm.

Then it's not the PR15 causing the fart out.

 

[themickster]

Can you post a soundbite in here?

 

[eniac]

All EQ are at noon,preamp at 9o'clock,so pretty low,and volume adjusted with the master volume control.

CTM100 tone controls are passive, so their behavior probably mimics (but may not exactly duplicate) a Fender-style tone stack. I'm guessing the all-noon setting you're using is a significant departure from true flat.

 

[S-Bigbottom]

this is just in the house when i'm testing it,so not too loud.Thanks.

Take the cab outside.

There can be something in the house vibrating making it sound blown.
Many times people swear a cab is blown but it is that one small thing on a shelf vibrating, even though it sounds like it is coming from the cab.

Low G in my house sounds nasty, but is clear everywhere else.