Freakin' And Peakin'!!!!!

[similost]

Talk about the coolest thing I have ever seen..

I've got a pair of Community MVP speakers, and I finally decided push them to the limit.. and that's when the coolest light show I've ever seen started..

On the back of the speakers, they have a red LED clip light.. but inside, showing through the ports, and around the 15"... it lights up BIGTIME inside the speaker when clipping.. .so even from the front, you know you are pushing them too far.. it's getting too late tonight, (neighbors) but tomorrow, I'll try and get a picture.. never seen anything liket it... TOO COOL!!!! looks like lightning kinda.. besides these speakers sounding fantastic, the light show makes them the coolest speaker I've ever seen, much less heard...

 

[Dan ʕ•ᴥ•ʔ]

Probably a 12V auto bulb to protect the drivers from clipped signals. Ampeg and others have been doing it for decades. Pretty cool. huh?

 

[Paul C]

Eminence crossovers have those bulbs build into the tweeter portion. As the bulb heats up, it increases resistance and gives a "soft limiting" to the tweeter.

 

[Dan ʕ•ᴥ•ʔ]

Speaking of which, had a fella bring me a new (to him) Acme 2x10 bass cab, all in a tiz because "something was on fire when (he) played loud!" I assured him all he was seeing was the light bulb doing its job.

 

[similost]

Speaking of which, had a fella bring me a new (to him) Acme 2x10 bass cab, all in a tiz because "something was on fire when (he) played loud!" I assured him all he was seeing was the light bulb doing its job.

Now that's funny, because my wife saw it first, I was behind the speaker, and she started pointing at it with a really freaked look on her face.. I realized what it was when I saw it, and turend it down and told her I was pushing it too far... but never heard of this or seen it before.. the coolest thing I've ever seen.. and what was even more impressive was they weren't distorted sounding at all.. still really nice and clean...

 

[Dan ʕ•ᴥ•ʔ]

Yep...as Paul noted...soft limiting. :yes:

 

[Urizen]

Yep...as Paul noted...soft limiting. :yes:

By placing a tube in the circuit?

 

[similost]

Yep...as Paul noted...soft limiting. :yes:

so I guess kinf of like a resister, or a cap to soak up the excess energy, but not quite? Never heard of this before...

 

[RayW]

so I guess kinf of like a resister, or a cap to soak up the excess energy, but not quite? Never heard of this before...

Thermistor is the term. As it gets hotter the resistance goes up and limits the current.

I remember Bose using them in their subs back in the 90's. They advertised the subs as taking infinite power. If you put more than about 100W into them the thermistor lit up like a Christmas tree. The sales weasel at the shop I was in thought it was the coolest thing since the Victrola.

Ray

 

[similost]

Thermistor is the term. As it gets hotter the resistance goes up and limits the current.

I remember Bose using them in their subs back in the 90's. They advertised the subs as taking infinite power. If you put more than about 100W into them the thermistor lit up like a Christmas tree. The sales weasel at the shop I was in thought it was the coolest thing since the Victrola.

Ray

aaahhhh... ok.. now I understand.. forgot I read about thermisters before.. never seen it in practice before..

 

[averagewhiteman]

So That"s What Those Are!

AK, always some good info.

My Dad gave me some Bose 701's (purchased mid nineties) a few years ago. I drove them past their peak, and the oblong front ports LIT UP big time.

I thought it was some type of warning. and the speakers sustained no damage. I told Dad about it, right after I told him I sold the 701's and purchased an sx-1050 and some HPM-700's with the proceeds.

 

[dc270]

I found the 12v bulbs in a lot of the Norman Labs xover designs. It works tretty well....until the bulb burns out!!

I like to never found out why my tweeter quit until I tested the bulb!
DC

 

[bowtie427ss]

Truly pushed to the "limit" will render you in need of new bulbs.

The bulb, or in the case of a few of my networks which have pairs of bulbs paralleled, serve as a current "drain" in effect adding compression to the HF circuit.

FWIW, big enough HF transients will take out the HF driver as well as the bulbs. Tho they may be fun to watch, they represent current being produced by your amplifier, that's not being given up as sound.