Blown speakers question.
Registered User
Joined: Oct 2002
Posts: 7,584
Likes: 1
From: Baton Rouge, LA
imo -- when recommending to someone who's low to moderate experienced, i suggest keeping your amplifier's RMS wattage output to within 90% to 125% of the rated RMS (or continuous) wattage for the speakers.
i'd suggest not working w/ much under 100Wrms to the front speakers for this car.
so, i'd suggest you shop speakers and an amplifier as such.
for your distortion questions:
just about all of the time, distortion that will damage your speakers is clearly audible. there are fundamentally 2 types of distortion, mechanical and clipping distortion.
mechanical is when you are physically forcing the speaker to move beyond the parameters it was designed for...
this can have several different sounds as signals... the speaker will sound like it's fluttering, popping (like a mechanical strike) at max excursion, and/or making a farting type sound (pffftt) at strong beats or bass notes.
you can't run a speaker at these conditions for long before you're going to do damage... this is the distortion most people think of when you discuss the topic.
clipping is when you're driving the amplifier (pre-amp or main amp) at levels to where the waveform signal exceeds the dynamic range of the amplifier. i know that's probably not helpful, so here's an analogy...
an amplifier can only make so much power... it has a ceiling as it were, which represents the power limit. now, if i stick a trampoline in the room to represent my signal (music), and i start jumping. as long as my jumps are lower than the ceiling, everything is good.
but, when i start getting some big jumps (turning up the volume), i'm going to start hitting the ceiling w/ my head. now, i can do that for a while, especially if i'm not hitting it hard.
but if i jump harder (turn it up louder), i'm gonna start hitting the ceiling very hard. and it's gonna hurt. because the power i'm bringing from my jump is being changed from upward speed to a *WHAM*.
when you start hitting the ceiling of the amp's ability (dynamic range), you're "clipping" the top of the signal off (ie, hitting your head, and not getting a full jump). that clipping is a distortion to the sound.
a little clipping you won't even notice... but a lot of clipping will do damage in time.
now, i'm sure you're wondering, what does this sound like... well, it's harder to detect, especially at low levels. it kinda sounds like a "blurring" of the music. like it's fuzzy at the edges or something. that's because a truncated waveform (ie, top clipped) creates harmonics at frequency multiples... so, you hear notes that don't exist.
here's a couple clips that should give you a better idea (from http://www.bcae1.com):
borrowing from this page: http://www.bcae1.com/2ltlpwr.htm
(these can be loud, so turn down your volume until you've tested them out at least once)
here's a 1000 hz signal that is alternately clipped and pure
here's a 100 hz signal that is alternately clipped and pure
and here's a song w/ the left channel clipped severely and the right channel clean
that should give you an idea of what you're listening for...
from that site:
the image mentioned can be found at the bottom of the page i linked you to...
there's also a ton of basic car audio info on this page: http://www.bcae1.com/installationprimer.htm
and in the FAQ at the top of the Electronics section
i'd suggest not working w/ much under 100Wrms to the front speakers for this car.
so, i'd suggest you shop speakers and an amplifier as such.
for your distortion questions:
just about all of the time, distortion that will damage your speakers is clearly audible. there are fundamentally 2 types of distortion, mechanical and clipping distortion.
mechanical is when you are physically forcing the speaker to move beyond the parameters it was designed for...
this can have several different sounds as signals... the speaker will sound like it's fluttering, popping (like a mechanical strike) at max excursion, and/or making a farting type sound (pffftt) at strong beats or bass notes.
you can't run a speaker at these conditions for long before you're going to do damage... this is the distortion most people think of when you discuss the topic.
clipping is when you're driving the amplifier (pre-amp or main amp) at levels to where the waveform signal exceeds the dynamic range of the amplifier. i know that's probably not helpful, so here's an analogy...
an amplifier can only make so much power... it has a ceiling as it were, which represents the power limit. now, if i stick a trampoline in the room to represent my signal (music), and i start jumping. as long as my jumps are lower than the ceiling, everything is good.
but, when i start getting some big jumps (turning up the volume), i'm going to start hitting the ceiling w/ my head. now, i can do that for a while, especially if i'm not hitting it hard.
but if i jump harder (turn it up louder), i'm gonna start hitting the ceiling very hard. and it's gonna hurt. because the power i'm bringing from my jump is being changed from upward speed to a *WHAM*.
when you start hitting the ceiling of the amp's ability (dynamic range), you're "clipping" the top of the signal off (ie, hitting your head, and not getting a full jump). that clipping is a distortion to the sound.
a little clipping you won't even notice... but a lot of clipping will do damage in time.
now, i'm sure you're wondering, what does this sound like... well, it's harder to detect, especially at low levels. it kinda sounds like a "blurring" of the music. like it's fuzzy at the edges or something. that's because a truncated waveform (ie, top clipped) creates harmonics at frequency multiples... so, you hear notes that don't exist.
here's a couple clips that should give you a better idea (from http://www.bcae1.com):
borrowing from this page: http://www.bcae1.com/2ltlpwr.htm
(these can be loud, so turn down your volume until you've tested them out at least once)
here's a 1000 hz signal that is alternately clipped and pure
here's a 100 hz signal that is alternately clipped and pure
and here's a song w/ the left channel clipped severely and the right channel clean
that should give you an idea of what you're listening for...
from that site:
Music Clipped:
The following link is a sample of music in MP3 format. The left channel is severely clipped. The right channel is clean. Use the balance slider on your MP3 software to shift from left to right. In the picture below, you can see that the top (left) signal is clipped and the bottom (right) signal is not. The image was taken directly from the wavefile that was converted to the MP3 file below. When listening to the file, pay special attention to the bass drum track.
As a side note...
Even though the signal is severely clipped, it can be difficult to hear at some points in the track. When you hear someone driving their amplifiers so far into clipping that it's clearly audible, you'll know that the waveform that's being sent to the speakers doesn't even resemble the original waveform.
The following link is a sample of music in MP3 format. The left channel is severely clipped. The right channel is clean. Use the balance slider on your MP3 software to shift from left to right. In the picture below, you can see that the top (left) signal is clipped and the bottom (right) signal is not. The image was taken directly from the wavefile that was converted to the MP3 file below. When listening to the file, pay special attention to the bass drum track.
As a side note...
Even though the signal is severely clipped, it can be difficult to hear at some points in the track. When you hear someone driving their amplifiers so far into clipping that it's clearly audible, you'll know that the waveform that's being sent to the speakers doesn't even resemble the original waveform.
there's also a ton of basic car audio info on this page: http://www.bcae1.com/installationprimer.htm
and in the FAQ at the top of the Electronics section
Registered User
Joined: Sep 2006
Posts: 263
Likes: 0
From: Cocoa Bch, Fl
Perfect...this is gonna take me a few hours to absorb and ponder before my next questions, however here's what I'm planning to install as a ponit of discussion.
Alpine 9857 H/U
specs: http://www.alpine-usa.com/en/products/prod...7&lang=en&tab=F
Alpine Amp PDX 150x2
specs: http://www.alpine-usa.com/en/products/prod...0&lang=en&tab=F
Boston Acoustic Pro 60's
specs: http://www.bostonacoustics.com/car/car_pro...&product_id=296 (check quick specs)
I'm hoping this will be a balanced system that provides great sound with minimum risk of damage. It seem that I'm gonna need to also be careful with our MP3's also, based on your clipping comments.
Alpine 9857 H/U
specs: http://www.alpine-usa.com/en/products/prod...7&lang=en&tab=F
Alpine Amp PDX 150x2
specs: http://www.alpine-usa.com/en/products/prod...0&lang=en&tab=F
Boston Acoustic Pro 60's
specs: http://www.bostonacoustics.com/car/car_pro...&product_id=296 (check quick specs)
I'm hoping this will be a balanced system that provides great sound with minimum risk of damage. It seem that I'm gonna need to also be careful with our MP3's also, based on your clipping comments.
Registered User
Joined: Oct 2002
Posts: 7,584
Likes: 1
From: Baton Rouge, LA
*nods*
saw your install. excellent choice all around, and very clean looking install.
glad to hear you're loving it.
oh, and don't fret too much about distortion killing your stuff. just keep your ears open. if you can hear the distortion altering the music, chances are it's too loud.
saw your install. excellent choice all around, and very clean looking install.
glad to hear you're loving it.
oh, and don't fret too much about distortion killing your stuff. just keep your ears open. if you can hear the distortion altering the music, chances are it's too loud.
Registered User
Joined: Sep 2006
Posts: 263
Likes: 0
From: Cocoa Bch, Fl
Good point on distortion...thanks
The new system is more than loud enough with the top down, no matter the speed.
I'm going to try and gather some temp reading around the amp to see what my actuals are and hope I'm within band in respects to that. It's got an air gap all arounf the amp so hope fully I won't ahve a problem. I'll post that data when I get it.
The new system is more than loud enough with the top down, no matter the speed.
I'm going to try and gather some temp reading around the amp to see what my actuals are and hope I'm within band in respects to that. It's got an air gap all arounf the amp so hope fully I won't ahve a problem. I'll post that data when I get it.
Registered User
Joined: Oct 2002
Posts: 7,584
Likes: 1
From: Baton Rouge, LA
iirc, the PDX is a digital class amp. it should run cool under most circumstances. i would very much like it if you did report back your details, as this community is always interested in small cool running amps.
looks like you're in the South w/ me. hopefully, we'll run into each other at a meet sometime and can compare some notes.
the SESM (Southeastern Super Meet) is coming up in June, and WTD is coming probably in April/May sometime.
looks like you're in the South w/ me. hopefully, we'll run into each other at a meet sometime and can compare some notes.
the SESM (Southeastern Super Meet) is coming up in June, and WTD is coming probably in April/May sometime.
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