Speaker overload (tweeter) protection using bulbs (repost)

[Eeyore]

in practice, audible distortion is a warning that you should
turn down the volume.

Couldn't agree more.

The distortion I was talking about was the sort that comes from pushing it
into its excursion limits.

(X max)

Precisely. I have a lovely pair of Altec diaphragms in my "rogue's gallery" that
demonstrates this perfectly. The voice coils meaure 100% OK and look OK.

Graham

 

[Eeyore]

bottoming(or farting) a woofer is truely a horid sound

That's technically exceeding X max (Thiele and Small parameters). Easy to do
with ported cabs and no suitable high order HPF.

Mine (my client's) is 24dB/octave @ 35Hz.

Graham

 

[liquidator]

Glad to hear it. I don't suppose you're a musician who uses Wharfe
gear or repairs pro audio gear for a living, but rather just another
consumer or retailer who has an opinion.

As far as the Behringer gear goes I have no experience with it so
other than seeing a lot of negative comments about it from those who
do use or repair it i have no opinion.

Behringer is like any company...some usable for semi pro, some absolute
garbage.

Thee odd thing is most negative comments about Behringer do NOT come from
users as you say.

Almost all negative posts about Behringer are from users of other brands.

It's no worse than any other cheap stuff, better sometimes. I don't us it,
but plenty of weekend warrriors do.

If Behringer was a s bad as people try to say, they would be out of
business.

Conclusion- many aof the negative posts are bull.

I don't use Behringer, or Mackie, or any of that kinda stuff. But I am not
gonna insist everybody drive the same brand of car I do.

 

[Eeyore]

Same brewery but this IPA
http://www.dogfish.com/brewings/Year_Round_Beers/90_Minute_IPA/11/index.htm

Are you familiar with the origin of the name 'IPA' ?

Graham

 

[Eeyore]

I like to protect gear from whatever might come, so I like lamps and polyswiches. I would
be almost as happy with a frequency-selective limiter that could independently account for
the thermal and displacement limits of the tweeter, mid and woofer (with appropriately
different time constants - an even greater challenge), but the reality is that a lamp in
the tweeter circuit handles 80% of abuse, so it's cheap insurance.

That's how I see it too. We don't get many lamps blown but it does happen, even in the EV
QRx's (almost once a year on average).

But an interesting twist is that with the simple 2nd order HPFs I have been trying (with a
very high Fc, eg 8 kHz, to flatten CD horn response and match sensitivities), a lamp or
polyswitch in the INPUT to the crossover has the nice benefit of also seeing more MF, and
so potentially account for both thermal and displacement limitations. Admittedly the time
constants cannot be independent as would really be required, but it's still better than
having the lamp in the crossover output circuit, and a LOT safer for the amp, which
becomes UNLOADED when the protection operates, instead of shorted.

Indeed it should ALWAYS be on the input side. Which is how ours are arranged. It just
disconnects the HPF.

Graham

 

[Eeyore]

Suggest you try driving a DC coupled amp into heavy clipping and see the
results to speakers which can nominally handle its output.

That's why I use 'clip eliminator circuits'. Did my first 18 years ago in the
1200B. Used a transconductance amp in a feedback loop (inactive until clip
sensed so no effect on normal signal).

Graham

 

[Eeyore]

put a 100% distored signal from a 1 watt amp into a 600 watt woofer and you
will not live long enough to see it burn out.

Uh ?

A 100% distorted signal would be a square wave of 2W rating. That's not going to
bother ANY 600W rated voice coil.

Graham

 

[Eeyore]

No, it isn't. You are cross posting to these groups:

news:sci.electronics.repair

More correctly I was, since the original question was relevant to all.

George should have trimmed the groups for pro-sound comments only.

Graham

 

[Eeyore]

No, it isn't. You are cross posting to these groups:

news:sci.electronics.repair

In practice, I think you'll find the subject matter is still of interest in
all of these.

Graham

 

[Eeyore]

And to suggest no pro equipment ever gets abused by pros is pie in the
sky...

Many a JBL D150 went to meet its maker in the 70s. In flames quite often.

Graham

 

[Eeyore]

Jeez- another idiot to killfiter- where are you pointing out what I said was
wrong?

Jamie is notorious (with me at least) for having some very odd ideas sometimes
in the electronics groups. I think he's a little bit out of touch with current
practice in this area.

Graham

 

[Eeyore]

Dave we've gooten off on the wrong foot, but what happens is Eeyore starts
these damn crossposts.

He has been asked a number of times to stop.

He's a nice fellow but he keeps staring into space and mumbling
"crossposting is good".

What it does is throw groups of people together who don't know each
other...it ALWAYS wstarts fights .PERIOD.

I wish Graham (Eeyore) would stops as he's been asked to- but he's convinced
he's right, and no amount of logic is gonna change that..

According to the currently accepted rules of netquette, a post that is relevant
to several groups SHOULD be cross-posted. Most certainly not multiposted.

Explain how it is off-charter in rec.audio.tech or sci.electronics.repair where
a lot of audio is discussed daily. It was a repair question after all ! And
technical.

Graham

 

[Eeyore]

Boy!, you're way out of your league..

Typical Jamie response.

Liquidator knows his stuff 99+ odd % of the time.

Graham

 

[Eeyore]

Glad to hear it. I don't suppose you're a musician who uses Wharfe
gear or repairs pro audio gear for a living, but rather just another
consumer or retailer who has an opinion.

He's a US (NY state AIUI) audio hire company operator.

As far as the Behringer gear goes I have no experience with it so
other than seeing a lot of negative comments about it from those who
do use or repair it I have no opinion.

Seen and heard of more Behringer gear die prematurely than any other brand that
one ought presumably to be able to take seriously.

Ron (UK) tried 2 of their big amps. Both went U/S just outside warranty.

OTOH, the venue I help out still has 2 of my Studiomaster D series amps working
day in, day out and both are 10+ yrs old. Only maintence needed, blowing out the
heatsinks and replacing a couple of scratchy gain pots. And you can replace those
pots in 15 mins compared to the over one HOUR it takes for a QSC RMX !

Graham

 

[Eeyore]

Thee odd thing is most negative comments about Behringer do NOT come from
users as you say.

I've experienced their stuff fail on one of my clients. He will NOT buy
Behringer any more. He has a BUSINESS to run that requires RELIABILITY.

Graham

 

[Eeyore]

You would have flunked electronics 101.

Clipping and DC are not the same thing. That argument was selltled years
ago- only those with minimal knowledge advance it today.

In the early days of DC coupled outputs, some amps still had a degree of
internal AC coupling or bypassing in the drive circuitry.

They could indeed 'drift' DC under prolonged overdrive.

Graham

 

[Eeyore]

"Jamie" wrote in message

What is this "amplifier saturation" you talk of ? Please use accepted
terminology.

Ahnothetr person with minimal knowledge.

This is my experience of Jamie too. He reckons he's some hot shot but constantly
uses the wrong words to describe things for example. His knowledge is also very
dated.

Graham

 

[Eeyore]

I feature mostly Meyer Sound Labs gear for the serious rig and behringer for
the disposable low end crap

I'd love to lnow if Behringer gear destined for the N.A. market still uses
leaded solder. Could exaplin a LOT ! Any chance of asking Jim Savery. I've lost
his contact details.

Graham

 

[Jamie]

liquidator wrote:




What is this "amplifier saturation" you talk of ? Please use accepted
terminology.





This is my experience of Jamie too. He reckons he's some hot shot but constantly
uses the wrong words to describe things for example. His knowledge is also very
dated.

Graham

Graham, you play with toys.. you work with toys.. and as usual,
all you have left is finger pointing because you've lost what ever
you had. That is, if you had anything of value to start with other
than what you find off the backs of others.

Your knowledge of electronics is most likely gained from destroying
an untold amount of components and still to this day, you have to
scratch that bold head of yours and wonder what you did with that last
puff of smoke you allowed to escape.

You boast that your an elite in audio design, from what I've seen you
point out. A mear amateur, expert you are not!.

Thank you and have a nice day, BSA..

http://webpages.charter.net/jamie_5"

 

[Jamie]

Jamie wrote:




Typical Jamie response.

Liquidator knows his stuff 99+ odd % of the time.

Graham

It's not shocking that you would side with him. If I
didn't know any better, the two of you must be collaborating.

It would explain a lot of things.

Graham, the hole your digging is getting bigger.
Please watch your step, I wouldn't want to see any one get
hurt now.

You are not an elite in audio design or any other for that fact,
get over your self. I'm sure you're good for something and maybe
one day you'll find it.


http://webpages.charter.net/jamie_5"