Speaker noise / distortion

[Disco Leisure UK]

Hi guys. our lads did a gig last night and took out 2 class d JAC12s and 2 class d CD15s subs. They connected from amp to JAC12s then to subs bringing the amp to 4 ohms, the amp is a stageline STA1100 with a rating of 400wrms per side at 8 ohms and 600wrms per side at 4 ohms. During the night as the sound went up the lads informed me that the speakers were crackling / distorting and was even more when on the microphone, I asked if the amp was clipping by any chance and they said no and that the amp was on 3 quarters of the way round on the volume controls, I mentioned that the amp was probably underpowered to run all the speakers as the JAC12s are 300wrms per side and the subs are 350wrms per side, we basically argued all night afterwards about this, they say that the amp is not underpowered, I say it most probably is, can any of you guys advise on this...cheers....:confused:

[DeckstarDeluxe]

test it out with all of you there?

Its hard to poke your head in on things like this as might be other external factors causing the proplem.

[Disco Leisure UK]

test it out with all of you there?

Its hard to poke your head in on things like this as might be other external factors causing the proplem.


We are due to test in the garage later today, I personally used the amp and the JAC12s last week without the subs and they sounded spot on no distortion, even the signal lights on the amp were not flashing, since the subs were connected last night it developed the distortion, so im thinking amp or subs???

[DeckstarDeluxe]

what about the output of the mixer? Was that clipping? Maybe the gain settings?

[CRAZY K]

Hi guys. our lads did a gig last night and took out 2 class d JAC12s and 2 class d CD15s subs. They connected from amp to JAC12s then to subs bringing the amp to 4 ohms, the amp is a stageline STA1100 with a rating of 400wrms per side at 8 ohms and 600wrms per side at 4 ohms. During the night as the sound went up the lads informed me that the speakers were crackling / distorting and was even more when on the microphone, I asked if the amp was clipping by any chance and they said no and that the amp was on 3 quarters of the way round on the volume controls, I mentioned that the amp was probably underpowered to run all the speakers as the JAC12s are 300wrms per side and the subs are 350wrms per side, we basically argued all night afterwards about this, they say that the amp is not underpowered, I say it most probably is, can any of you guys advise on this...cheers....:confused:

Might be worth ringing Class D to check on their view--are you sure about the wiring--using Peaveys sub and high pass filter you go to the sub first and then to the tops. It automatically adjust everything back to 4 ohms so theres no problem.

CRAZY K

[Disco Leisure UK]

Might be worth ringing Class D to check on their view--are you sure about the wiring--using Peaveys sub and high pass filter you go to the sub first and then to the tops. It automatically adjust everything back to 4 ohms so theres no problem.

CRAZY K

Spoke to peter at class d about 6 weeks ago, he says that if you go to the JAC12s first then to the subs it will show 4 ohms, if you go to the bins then the tops then it will show 8 ohms

[Disco Leisure UK]

what about the output of the mixer? Was that clipping? Maybe the gain settings?

Mixer not clipping, they kept well within the green / amber lights, master volume on mixer set a 8

[CRAZY K]

Spoke to peter at class d about 6 weeks ago, he says that if you go to the JAC12s first then to the subs it will show 4 ohms, if you go to the bins then the tops then it will show 8 ohms

Fair enough--is it the tops or bass bins that distort or both:eek:

CRAZY K

[Disco Leisure UK]

Fair enough--is it the tops or bass bins that distort or both:eek:

CRAZY K

Just the tops which slightly distort, we have tested the sound in the garage and have heard it for myself, I gradually increased the sound to the levels they had it last night and can confirm now that they were JUST touching the clip light (just a quick flash) which made me think that they were running the amp at its peak?. I set the amp to 3 quarters of a turn on the amp volume controls like they had it last night. It may be possible that I may need a larger amp with a little more headroom?