Tech: Subwoofer pulsing

[paco)))]

Hello, sorry if this is the wrong group to ask this. My jbl sub 135 is
pulsing hard when it's turned on & I have no idea what's causing this.
Does anyone know what it might be? Thanks for any advice!

~Chris

[Mark P.]

On 12 Mar 2007 08:55:51 -0700, "paco)))" <cjohnson99@cox.net> wrote:

>Hello, sorry if this is the wrong group to ask this. My jbl sub 135 is
>pulsing hard when it's turned on & I have no idea what's causing this.
>Does anyone know what it might be? Thanks for any advice!
>
>~Chris


Some subs to that. My big Difinative sub thumps when turned off and
on so I leave it on all the time.

Mark P

[paco)))]

On Mar 12, 12:26 pm, Mark P. <m...@00000.net> wrote:
> On 12 Mar 2007 08:55:51 -0700, "paco)))" <cjohnso...@cox.net> wrote:
>
> >Hello, sorry if this is the wrong group to ask this. My jbl sub 135 is
> >pulsing hard when it's turned on & I have no idea what's causing this.
> >Does anyone know what it might be? Thanks for any advice!
>
> >~Chris
>
> Some subs to that. My big Difinative sub thumps when turned off and
> on so I leave it on all the time.
>
> Mark P

I'm sorry, I meant it just pulses over & over again as soon as I turn
it on & even with no signal going to it. Just bam bam bam....

[Gandalf]

paco))) wrote:
> On Mar 12, 12:26 pm, Mark P. <m...@00000.net> wrote:
>> On 12 Mar 2007 08:55:51 -0700, "paco)))" <cjohnso...@cox.net> wrote:
>>
>>> Hello, sorry if this is the wrong group to ask this. My jbl sub 135 is
>>> pulsing hard when it's turned on & I have no idea what's causing this.
>>> Does anyone know what it might be? Thanks for any advice!
>>> ~Chris
>> Some subs to that. My big Difinative sub thumps when turned off and
>> on so I leave it on all the time.
>>
>> Mark P
>
> I'm sorry, I meant it just pulses over & over again as soon as I turn
> it on & even with no signal going to it. Just bam bam bam....
>

Does it still reproduce audio or only the pulsing?

Does the pulsing occur with no input cable?
["even with no signal" doesn't necessarily mean you unplugged the cable]

Enquiring minds want to know.

--
-Gandalf

Never meddle in the affairs of a dragon for you are crunchy and taste
good with ketchup!

[paco)))]

On Mar 12, 2:24 pm, Gandalf <gand...@rivendell.bog> wrote:
> paco))) wrote:
> > On Mar 12, 12:26 pm, Mark P. <m...@00000.net> wrote:
> >> On 12 Mar 2007 08:55:51 -0700, "paco)))" <cjohnso...@cox.net> wrote:
>
> >>> Hello, sorry if this is the wrong group to ask this. My jbl sub 135 is
> >>> pulsing hard when it's turned on & I have no idea what's causing this.
> >>> Does anyone know what it might be? Thanks for any advice!
> >>> ~Chris
> >> Some subs to that. My big Difinative sub thumps when turned off and
> >> on so I leave it on all the time.
>
> >> Mark P
>
> > I'm sorry, I meant it just pulses over & over again as soon as I turn
> > it on & even with no signal going to it. Just bam bam bam....
>
> Does it still reproduce audio or only the pulsing?
>
> Does the pulsing occur with no input cable?
> ["even with no signal" doesn't necessarily mean you unplugged the cable]
>
> Enquiring minds want to know.
>
> --
> -Gandalf
>
> Never meddle in the affairs of a dragon for you are crunchy and taste
> good with ketchup!

Well, I was given this sub because a friend was going to throw it
away. I haven't hooked it to my system for fear of messing my stuff
up. All I know is I plugged it in to the wall & flipped the switch to
on & there it goes, no input cables hooked up or anything. Just bam
bam bam! The speaker just flexes in & out fully & repeatedly.

[Gandalf]

paco))) wrote:

<snip>

> Well, I was given this sub because a friend was going to throw it
> away. I haven't hooked it to my system for fear of messing my stuff
> up. All I know is I plugged it in to the wall & flipped the switch to
> on & there it goes, no input cables hooked up or anything. Just bam
> bam bam! The speaker just flexes in & out fully & repeatedly.

I think you now know why your friend was going to throw it away.
It certainly sounds as though the amp is blown.

As to whether or not it's worth the repair is dependent on a number of
factors. I can't find very much info about it, other than it's about 4
years old, part of a HTIB solution, and rather 'entry-level'.

It probably utilizes STK [or similar] output ICs as opposed to discrete
components. What that means is parts are relatively inexpensive and
troubleshooting is virtually unnecessary. Of course it also means it's
probably not worth it when it does work. :p

I'd say, unless you have a friend qualified to repair it for the cost of
parts and a six-pack, yank the speaker for the helluvit and toss the
rest in the trash.

Just my .02c
--
-Gandalf

Never meddle in the affairs of a dragon for you are crunchy and taste
good with ketchup!

[paco)))]

On Mar 12, 7:20 pm, Gandalf <gand...@rivendell.bog> wrote:
> paco))) wrote:
>
> <snip>
>
> > Well, I was given this sub because a friend was going to throw it
> > away. I haven't hooked it to my system for fear of messing my stuff
> > up. All I know is I plugged it in to the wall & flipped the switch to
> > on & there it goes, no input cables hooked up or anything. Just bam
> > bam bam! The speaker just flexes in & out fully & repeatedly.
>
> I think you now know why your friend was going to throw it away.
> It certainly sounds as though the amp is blown.
>
> As to whether or not it's worth the repair is dependent on a number of
> factors. I can't find very much info about it, other than it's about 4
> years old, part of a HTIB solution, and rather 'entry-level'.
>
> It probably utilizes STK [or similar] output ICs as opposed to discrete
> components. What that means is parts are relatively inexpensive and
> troubleshooting is virtually unnecessary. Of course it also means it's
> probably not worth it when it does work. :p
>
> I'd say, unless you have a friend qualified to repair it for the cost of
> parts and a six-pack, yank the speaker for the helluvit and toss the
> rest in the trash.
>
> Just my .02c
> --
> -Gandalf
>
> Never meddle in the affairs of a dragon for you are crunchy and taste
> good with ketchup!

That's pretty much what I figured I'd end up doing. I have another sub
upstairs with the same size speaker so who knows, if that one ever
blows or sumptin I might have a spare now. Thanks for the info!