at risk of blowing speakers?

justinhedrick · October 20, 2011, 11:56:42 AM

so, i experimented with boosting my EQ at practice on tuesday, i use a VTM 60 into a randall 2x15 that's rated at 150 or 160 watts (it was made for bass back in the 80s). mostly adding more low end and some more mids while cutting the highs.

it sounded really good, and when pushed with my rat pedal sounded awesome, but there was so much low-end i was worried i was going to blow the speakers. i thought i heard some speaker distortion, but it was loud, i can't be sure.

so . . . should i stay awake at night worrying about this?

RAGER · October 20, 2011, 12:00:46 PM

I wouldn't. A VTM 60 into a cab that's rated @150 watts or so? Doesn't sound like a recipe for disaster to me.

justinhedrick · October 20, 2011, 12:07:35 PM

Quote from: RAGER on October 20, 2011, 12:00:46 PM
I wouldn't. A VTM 60 into a cab that's rated @150 watts or so? Doesn't sound like a recipe for disaster to me.

oh, and i'm also going to be adding another cab to the equation next week. it's rated at 150 watts as well, so that would be a 60 watt head into 300 watts worth of speakers, right? (i'm running the cabs in a series/parallel configuration).

RAGER · October 20, 2011, 01:03:18 PM

You mean you're running the cabs parallel? or series. it's one or the other. individual speakers in a cabinet can be wired series/parallel

justinhedrick · October 20, 2011, 01:07:33 PM

Quote from: RAGER on October 20, 2011, 01:03:18 PM
You mean you're running the cabs parallel? or series. it's one or the other. individual speakers in a cabinet can be wired series/parallel

well, i had a box built so i can run my 2 four ohm cabs off the 8 ohm output of my head. so, the ran in parallel, but the cabs are wired as series. basically i'm running 2 cabs like a typical 4x12 would be wired (series/parallel).

SpaceTrucker · October 20, 2011, 01:31:07 PM

Your not gonna blow that cab. Now, my vtm120 cranked up into it might, Cause of over excursion. But if your playing, even downtuned guitar into a bass cab your not gonna hurt it. Unless you start hearing a clicking sound(from the speakers going in so far they hit the magnet.), then you need to back it off.

justinhedrick · October 20, 2011, 01:53:38 PM

Quote from: SpaceTrucker on October 20, 2011, 01:31:07 PM
Your not gonna blow that cab. Now, my vtm120 cranked up into it might, Cause of over excursion. But if your playing, even downtuned guitar into a bass cab your not gonna hurt it. Unless you start hearing a clicking sound(from the speakers going in so far they hit the magnet.), then you need to back it off.

awesome. rock on.

dunwichamps · October 20, 2011, 01:59:59 PM

you will not blow it but you might get speaker clipping, u may or may not like that

Hemisaurus · October 20, 2011, 02:43:23 PM

The peaks can damage it, if your pushing the cone beyond it's excursion limits, you won't burn out the voice coil, but you can damage the former if it goes beyond the gap, or smacks back against the back plate. You'll be happier once you get your other cab in place. Is it a sealed or a ported box?

A sealed box has more resistance against over excursion than a ported one, but oftentimes what you think is speaker distortion could be vibration from the cab, is it all tight, drivers, panels, jacks, handles etc. Does the noise go away if you move your head off the cab? Once I play beyond a certain volume, I have to move the head off the cab, no matter how damn heavy the head is.

RacerX · October 20, 2011, 02:59:20 PM

QuoteOnce I play beyond a certain volume, I have to move the head off the cab, no matter how damn heavy the head is.

I never put my head on my cabs. Poor old girl doesn't need to be vibrated any more than she already has over the years. It's off to the side on top of a milk crate for her.

justinhedrick · October 20, 2011, 03:18:13 PM

Quote from: RacerX on October 20, 2011, 02:59:20 PM
QuoteOnce I play beyond a certain volume, I have to move the head off the cab, no matter how damn heavy the head is.

I never put my head on my cabs. Poor old girl doesn't need to be vibrated any more than she already has over the years. It's off to the side on top of a milk crate for her.

thinking about it, i think the vibration is from the tubes, probably the first pre amp tube.

i don't have any milk crates to place it on, but i could just set it on it's side i guess . . . i wish i could afford a cool head box.

hemi, it is a sealed cab if memory serves. it MAY have a small port on the bottom. i haven't had the grill cloth off in so long. it is pretty tight, the speaker are front loaded and the back baffle can't come off.

my kustom cab is ported, if you can call it that.

Hemisaurus · October 20, 2011, 03:28:30 PM

Quote from: justinhedrick on October 20, 2011, 03:18:13 PM
Quote from: RacerX on October 20, 2011, 02:59:20 PM
QuoteOnce I play beyond a certain volume, I have to move the head off the cab, no matter how damn heavy the head is.

I never put my head on my cabs. Poor old girl doesn't need to be vibrated any more than she already has over the years. It's off to the side on top of a milk crate for her.

thinking about it, i think the vibration is from the tubes, probably the first pre amp tube.

i don't have any milk crates to place it on, but i could just set it on it's side i guess . . . i wish i could afford a cool head box.

hemi, it is a sealed cab if memory serves. it MAY have a small port on the bottom. i haven't had the grill cloth off in so long. it is pretty tight, the speaker are front loaded and the back baffle can't come off.

my kustom cab is ported, if you can call it that.

Well it's no real nevermind, just more curious. You just have to figure if your speakers are going beyond their limits, or if you are just hearing cabinet rattles. 90% of the time, the rattles in my Peavey are cured by me taking a hammer to the grille frame and knocking it back in. I spent a lot of time putting extra screws in those panels though 2" long, which was probably overkill, but hey it makes nary a squeak now. Pop the grille cloth off, if it's one of those frame dealios, or if it's metal, best thing I did for my 18 was replace the metal grille with one of those circular ones that just clamp against the speaker rim.