help! facts are hard to find!!

here is a post from some one in a forum,who i disagree with,il reply with what i think in bold.its just my opinon,im lookin this up on the net,but its hard to find real stuff!! tell me what u think!
_________________________________________________________________
From a Tom Nousaine post at the link below (not that easy to follow the very long UseNet discussion on the danger of clipping -- I read the entire thread and
I can't say there is agreement ...
but Tom does test speakers for a living,
so I'll assume his opinion is an expert opinion:

"The speaker never comes to a stop.

how does he know? when you see a 50hz sinewave being clipped,the actual clipped part will be very short,say 0.02seconds long im guessing,this is not long enough to see,but is plenty enough to be called Dc.

This idea is a fundamental misunderstanding that comes from that "DC" argument.

i disagree
I think it stems from the misunderstanding that the analog picture of a sine wave or square wave as it appears on the face of an oscilliscope is actually the 'signal' and the flat top is some kind of DC component.

an oscilloscople displays v/time division,this is represenative of the amp output,speaker input,is it not?

That picture is just an analog idea or representation of the sound or signal.

if oscilloscopes are so wrong,what is right,and why

As Mark began by saying (in his paper) there is no DC component ... he's right .... and therefore the cone never stops.

hes right because you say so?

Another part of the analysis that tends to get forgotten is that the tweeter's impedance will be rising as well and the only important harmonics will occur around the resonance area of the speaker.

im not sure about what hes meaning here.'important harmonics' ?

All this is not a criticsm of the work (paper).

The idea is well taken and right on the money.

You won't protect your speakers by using a larger amplifier.

a large amp wont clip

It will just burn them out as fast by supplying
more power no matter what the condition
of the signal."
it will burn them out ,if ur silly
TOM

quote from:
http://groups.google.com/groups?selm=20020228221328.28778.00001881@mb-fo.aol.com&output=gplain

:-S

and then i get confused cos seemingly intelligent people say things that arent logical

thanks
as usual

:^)
btw ive been loooking at the DEATHBOX at decware forums,it seems a load of BS,no real facts how it works,just a big funny ported thing,and ppl who build them tend to say its boomy at 60hz :-P
am i allowed to say things like that?? :) or is that an attack on them/...

_mike

That forum is probably the last place to get facts.

You can outperform a deathbox (dual 10" bandpass) with
a single 'monster' 12" or 15" in a 2 cf. box. /hehe

/marketing

If you want to do car audio, go here.
http://www.caraudioforum.com

You'll get straight answers.

HELP
btw jbl2226h in room-im getting high excursion wayne!!!! whats going on!?! :-S

my excursion is about the same as my 8inch on a conical pipe with the SAME amp.

to get similar midbass loudness i have to turn the amp up about 1/4 way around but ofcourse i get huge 33hz which wasnt there!.

also,if i have NO active filter,the highs of the sub, are SO LOUD like 20db or something crazy,that i turn my amp back to where i have it with my 8inch,sounds equal volume ,but little or non detectable bass.

is this the effect of the EBS? i didnt expect it to be that much!
only 5db lower at worst ,92db efficiency,
which is supposedly the efficiency of my 8inch conical pipe!

will get 240watt jaycar amp sometime.
im afraid how much excursion il get.i wish i could measure it somehow.

and no im not playing 10hz sine :P
Regards,
_Mike

I should first qualify that I have not yet been willing to afford a pair of 2226's, so I speak only from my experience listening to the speakers of others and running simulations.

I think the woofer wants a smaller box. Especially in home sized rooms, or near walls/corners. Maybe 124 liters tuned to 33. Would you be willing to try this driver in a smaller box? I think you will like it a lot. I noticed that all the ones I have heard were about 4 to 5 cubic feet.

Thomas F.

1st thing
i filter low pass LR 12db/octave at 70hz, i just did no filter, to compare it in loudness to my 8inch conical pipe sub,

there is a large difference in sound output.. i think im not used to EBS, the rising response is no trouble with the filter..

2nd thing
i think my tiny transformer cant supply my 30watt IC amp with enuf current.. which is a major prob, the va is probably less than equal to AMP rms rating which is VERY bad..

jaycar 240watt shud b good

my alignment
-it isnt ideal, but it should be okay with power. i rechecked its output with what power i have,its what i expect.. less than i remember.. perhaps i looked at it with 100watt and then replaced that with '20watt' in my head :-D its certainly the most output ive heard, so clean compared to any sub! my mates 2x kappa pro 10s dont match it for soudn quality and his subs are flying 2cm excursion with 1.3kw, such a waste :)

i have been listening to it more, it is surrepticiously louder than i thought, -its because im going lower freq, which is less detectable apart from rumble :-P
and im used to thumping45hz 8inch sub which ive found doesnt actualy sound that nice, and uses that thump to get abit louder :-D

im happy in the fact that i couldnt have bought from a better company

the only sub i cudve gotn was, SHIVA12 or JAYCAR 12 so i made good choice

next up, basshorn plans for it, to see if its viable :-)

thanks :-)
OH and also, im putting sound dampening material in it next time the speakers off, and siliconing around the frame to make sure its airtight cos it doesnt mate perfectly with the wood,
_mike

Another thing folks often forget when discussing music power is that it is riddled with amplitude and frequency modulations. There is the signal generated by high frequency instruments surfing on the signal generated by low frequency instruments. When an envelope generated by the performance of a bass or mid bass musician goes near or over the power limits of an amplifier the higher frequency waves modulated onto that envelope get cut off or lost since the amplified signal is driven above DC power rail. Yes, the amplifier is outputting DC at the rail voltage until the driving signal’s amplitude controls the power stage to drop below the rail voltage or something blows up.

The best way to see the true affects of clipping is to connect a silly scope to the amplifiers output that is connected to a loudspeaker and play some dynamic music while fiddeling with the silly scope’s knobs to get it to sync on the peaks. The good old Grateful Dead works well. Phil Lesh can hit some dynamics that puts the whole signal in the dumber. The volume can be adjusted to watch just the high frequencies getting cut off. AC\DC is good too the steady simple beat can be used to sync the scope almost perfectly. And watching the signal generated by Bonn Scott’s vocals is a good example of higher frequencies putting the amp into clipping. Folks have heard me speak and write about the “Bonn Scott vocal test” before. It’s easy to use to see and listen to an amp exceeding it’s limits.

The bottom line is there is very little RMS power causing an amp to clip. It’s mostly peak power. And when an amp is clipped it is outputting the amps DC rail voltage for that duration.