Car audio Rumours
09-29-2009, 03:51 PM
#51
LOL...
Fact some old gear is in fact better than newer gear. I run PPI, A/B. I just read the Damping factor article, and also like to add that I've heard it also depends on slew rate as well. I know from experience that my music sounds tighter, and more clear with running higher damping factor amps (and I mean real EDF values). Lots of the kids just see lights and sounds with today's equipment. There's truth to the saying...it's what's under the hood that counts.
by far the tightest bass I have ever heard a car audio amp produce.....period
it would probably wipe the floor with a couple of the Brystons and YBA'a I ahve played with
09-29-2009, 04:34 PM
#52
When i tried to inform him that the recone was done by Team PSI to give it a bit more punch (extra stiff spiders, woven tinsels) and that the box was designed by the same person for said speaker he just gave me a blank look.
So i went on to tell him that Team PSI is Dave who was like the brains behind all RE's speakers until his partners sold him out and that he also designed the box which was built to spec at 2.5 cft after displacement and with i think 31.5 sq inch of port tuned to 33 or something in that area. He didn't even flinch and went back to talking about his 152 and Vegas and drinking.
Anyways dinner is ready so thats enough for now. Maybe later ill fill you in on his rant about how Fi and DC and a few other decent umm "online" sub manufacturers were "nothing but backyard sub woofer manufacturers who dont know a thing about making speakers and all they do is assemble bought parts in there garages"
09-29-2009, 05:00 PM
#54
Ok.... so you asked for current draw and I gave it... so, how fast would a 1 farad cap discharge with a 600w amp on it 
and about the avatar... I just picked one of the generic ones that came with the board (long before I was an admin) I guess people just associate it to me now
and about the avatar... I just picked one of the generic ones that came with the board (long before I was an admin) I guess people just associate it to me now
09-29-2009, 05:16 PM
#55
Bryston makes amps for cars?? my dad has 2 old 4B's lying around that I want to put in my van with an inverter, but I think its well beyond unfair to compare amps for cars to amps for indoor use, because my ampzilla is rated at a great deal less than my 2500watt car amp, but when I hooked up a sub to it, the sub sounded wayyyyyyyyyyyyy better than it did in the van.
as for the whole cap thing, this might be an interesting read Why you don't need a capacitor - Realm of Excursion
particularly this part, which made me laugh
1.5 Farad cap lights the bulb for about …………5 minutes and 28 seconds
a giant cap lights the bulb for about……………. 54 minutes
a nine volt alkaline does so about …………………. 2 hours and 14 minutes
I think its safe to say that cap performance in subjective, because honestly I had one and my lights dimmed, then I put in a bigger battery and the dimming stopped, so I took it out, and it was installed for 2 years running the same 500wrms
09-29-2009, 06:30 PM
#56
500 Watt CAFz'r
Join Date: Jan 2008
Posts: 537
After about 35 milliseconds the cap will be at ~12.4 volts and effectively out of circuit (battery will dominate). What do I win?
09-29-2009, 06:39 PM
#57
09-29-2009, 06:51 PM
#58
after 35 milliseconds (your number) the cap is nothing more than an extra drain on the battery. Correct?
09-29-2009, 07:54 PM
#59
09-29-2009, 07:58 PM
#60
it's all blamed on Crowns Current Servo's....
they make shure the woofer cone is exactley where it is supposed to be
at all times
oh look...more BLING for this entertaining thread
What It Is DAMPING FACTOR
Tech Made Simple
Loudspeakers have a mind of their own. You send them a signal
and they add their own twist to it. They keep on vibrating after the
signal has stopped, due to inertia. That’s called “ringing” or “time
smearing.”
In other words, the speaker produces sound waves that are not part
of the original signal.
Suppose the incoming signal is a “tight” kick drum with a short
attack and decay in its signal envelope. When the kick-drum signal
stops, the speaker continues to vibrate. The cone bounces back and
forth in its suspension. So that nice, snappy kick drum turns into
a boomy throb.
Fortunately, a power amplifi er can exert control over the loudspeaker
and reduce ringing. Damping is the ability of a power
amplifi er to control loudspeaker motion. It’s measured in
Damping Factor, which is load impedance divided by amplifier
output impedance.
Let’s explain.
If the speaker impedance is 8 ohms, and the amplifi er output
impedance is 0.01 ohms, the damping factor is 800. That’s a
simplication. Since the speaker impedance and amplifi er output
impedance vary with frequency, so does the damping factor. Also,
the impedance of the speaker cable affects damping. Thick cables
(with low AWG) allow more damping than thin cables with (high
AWG).
The lower the amplifi er’s output impedance, the higher the damping
factor, and the tighter the sound is. A damping factor of 1000 or
greater is considered high. High damping factor equals tight bass.
How It Works
How does an amplifi er control speaker motion? When the loudspeaker
cone vibrates, it acts like a microphone, generating a signal
from its voice coil. This signal generated by the speaker is called
back EMF (back Electro Motive Force). It creates a current which
travels through the speaker cable back into the amplifi er output, then
returns to the speaker. Since back EMF is in opposite polarity with
the speaker’s motion, back EMF impedes or damps the speaker’s
ringing.
The smaller the amp’s output impedance, the greater is the effect
of back EMF on the speaker’s motion. An amplifi er with low output
impedance short-circuits the back EMF, so the back EMF drives the
loudspeaker with a relatively strong current that works against the
speaker’s motion. When the speaker cone moves out, the back EMF
pulls the speaker in, and vice versa.
In short, the loudspeaker damps itself through the amplifi er output
circuitry. The lower the impedance of that output circuitry, the more
the back EMF can control the speaker’s ringing.
To prove it to yourself, take a woofer that is not connected to
anything. Put your ear next to the cone and tap on it. You might
hear a low-pitched “bongggg” if the speaker itself is poorly damped.
Now short the speaker terminals and tap again. You should hear a
tighter thump.
Damping factor varies with frequency. As you might suspect, damping
factor is most important at low frequencies, say 10 Hz to 400
Hz.
Bottom Line......
Amps with a true high effective Damping Factor
deliver cleaner, tight kick drum and bass.
Tech Made Simple
Loudspeakers have a mind of their own. You send them a signal
and they add their own twist to it. They keep on vibrating after the
signal has stopped, due to inertia. That’s called “ringing” or “time
smearing.”
In other words, the speaker produces sound waves that are not part
of the original signal.
Suppose the incoming signal is a “tight” kick drum with a short
attack and decay in its signal envelope. When the kick-drum signal
stops, the speaker continues to vibrate. The cone bounces back and
forth in its suspension. So that nice, snappy kick drum turns into
a boomy throb.
Fortunately, a power amplifi er can exert control over the loudspeaker
and reduce ringing. Damping is the ability of a power
amplifi er to control loudspeaker motion. It’s measured in
Damping Factor, which is load impedance divided by amplifier
output impedance.
Let’s explain.
If the speaker impedance is 8 ohms, and the amplifi er output
impedance is 0.01 ohms, the damping factor is 800. That’s a
simplication. Since the speaker impedance and amplifi er output
impedance vary with frequency, so does the damping factor. Also,
the impedance of the speaker cable affects damping. Thick cables
(with low AWG) allow more damping than thin cables with (high
AWG).
The lower the amplifi er’s output impedance, the higher the damping
factor, and the tighter the sound is. A damping factor of 1000 or
greater is considered high. High damping factor equals tight bass.
How It Works
How does an amplifi er control speaker motion? When the loudspeaker
cone vibrates, it acts like a microphone, generating a signal
from its voice coil. This signal generated by the speaker is called
back EMF (back Electro Motive Force). It creates a current which
travels through the speaker cable back into the amplifi er output, then
returns to the speaker. Since back EMF is in opposite polarity with
the speaker’s motion, back EMF impedes or damps the speaker’s
ringing.
The smaller the amp’s output impedance, the greater is the effect
of back EMF on the speaker’s motion. An amplifi er with low output
impedance short-circuits the back EMF, so the back EMF drives the
loudspeaker with a relatively strong current that works against the
speaker’s motion. When the speaker cone moves out, the back EMF
pulls the speaker in, and vice versa.
In short, the loudspeaker damps itself through the amplifi er output
circuitry. The lower the impedance of that output circuitry, the more
the back EMF can control the speaker’s ringing.
To prove it to yourself, take a woofer that is not connected to
anything. Put your ear next to the cone and tap on it. You might
hear a low-pitched “bongggg” if the speaker itself is poorly damped.
Now short the speaker terminals and tap again. You should hear a
tighter thump.
Damping factor varies with frequency. As you might suspect, damping
factor is most important at low frequencies, say 10 Hz to 400
Hz.
Bottom Line......
Amps with a true high effective Damping Factor
deliver cleaner, tight kick drum and bass.
