BillFitzmaurice.info

metaverse wrote:

Rune Bivrin wrote: Speakers don't clip. They break...

However, if you find that the limiter is limiting a lot, chances are you need more speakers.

I'm assuming that is another way of saying "... in that case you should be using a smaller amp." ??

@ SH - thanks

No, not quite.

If the limiter is limiting most of the time you're probably trying to get more sound from the speakers than what they are designed for.
Adding speakers gives you more sound output, which is probably what you want.

Thanks for all the info guys

Digging another post up from the grave here so that I can be double sure i'm not going to break something ...

My question is :

While running my subs (channel 1) and tops (channel 2) via speakons with my crown xti4000 and setting the built-in limiter at -3db on both channels ... Can I then put my volt meter into A/C mode and attach the red and black meter pens to the red and black binding post outputs on channel 1 or 2 while the amp is powering the drivers via the speakon cables ??

Is that the proper way to test my amp's output voltage ??

Oh that would be loud! It would be better to have the speakers disconnected. The rest of what you posted is correct.

Do it with a sinewave in the middle of your subs' passband. No speakers required.

lol @ Tom

Ok, so I dont need to have any sound coming out of the drivers but I still need to have sound being sent to the input of the amp ??


@ Greg - Be careful with these new terms hahaha ... I learn like a 7 year old

Passband ... I'm totally lost

My favorite is the banana plug way (thanks to someone on this forum).

care to elaborate in some detail ?


Also ... when I set the limiter to say "-3db" on the crownxti4000 should I also be looking to limit the voltage to say 52volts (how?) as well ??

Passband, the band(width) allowed to pass through the crossover to the speaker

XIT limiter operation is a bit of a black box to me, but you nudge in 3dB increments until the voltage is less than the limit with the red lights on.

To answer, yes. Everything gets hooked up as usual except for the speakers.

This link gives a pretty good description http://billfitzmaurice.info/forum/viewt ... p?f=6&t=12

Rune Bivrin wrote: Speakers don't clip.

They do. A driver pushed past xmax reacts almost identically to an amp pushed past the rail voltage capacity. Guitar drivers are specifically designed to reach xmax at a very low percentage of Pe, so that they'll clip easily. They do so at as little as 5% of the Pe rating, so that there's plenty of room to push them hard without overheating the coil. Electric bass and PA woofers OTOH generally reach xmax at 40% or more of Pe; the Kappalites can reach 100% of Pe without exceeding xmax if properly loaded. That leaves far less margin for error between when you can hear them clipping and voice coil failure, making limiting a necessity. And of course in a folded horn you can't hear them clipping at all.

Bill Fitzmaurice wrote:

Rune Bivrin wrote: Speakers don't clip.

They do. A driver pushed past xmax reacts almost identically to an amp pushed past the rail voltage capacity. Guitar drivers are specifically designed to reach xmax at a very low percentage of Pe, so that they'll clip easily. They do so at as little as 5% of the Pe rating, so that there's plenty of room to push them hard without overheating the coil. Electric bass and PA woofers OTOH generally reach xmax at 40% or more of Pe; the Kappalites can reach 100% of Pe without exceeding xmax if properly loaded. That leaves far less margin for error between when you can hear them clipping and voice coil failure, making limiting a necessity. And of course in a folded horn you can't hear them clipping at all.

Well, yeah, I suppose so. Although I'd say in most of the cases we're interested in, a clipping driver is a driver on the way to driver heaven.

Guitar drivers are really a weird lot; more or less intentionally with low x-max, funky break-up modes and decidedly non-flat response. These days, that is. I'm sure they are built like that on purpose today because that's how we expect electric guitar to sound. Way back it was probably a result of trading quality for price and efficiency.

Kudos for reading the thread thoroughly; my comment was made nine months ago. I often wish posters would review the entire thread before chiming in. Not so much here, but on TalkBass most definitely.

Hello again ,


I'm finally getting around to testing my amp's voltage output but after 30min. of searching google I cannot find out how to tell what my speakers voltage handling limit is ...

What is the spec that tells me how much voltage my speaker can handle before it cooks ??

Bfm's subs are specified
Bfm tops are recommended half the RMS. Any top only gets 3db from the last half of the power and power compression eats some of that.

Watts is volts squared divided by impedance. Solve for volts.

More than anyone here I have to thank you the most for consistently helping me out and rescuing my half retarded ass - but i'm still feeling like a lost 10 year old n00b.