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#41
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Physics of bridging an amplifier - was: Damping Material
I was covering that in design, IMO car speakers should
be designed to withstand the elements common in a car. Back when Boston Acoustics came out with car speakers the first generation used a kind of a clear plastic cone, after a year or more the cones would try out and youcould put your finger through them like a stale cracker..... When they fixed that the next generation ALL of the foam surrounds rotted away after time.... Eventually they learned ..!! ha ha Boston isnt the only one that LEARNED the hard way there were many, and some that havent yet... ;-) Eddie Nousaine wrote: Eddie Runner ...snip....The ones where the customer just play the damn things too loud are typicly burned coils, but we probably see (in the bays) way more of other types of abuse on the drivers as well.... I see what Liz is saying, and you work in a lab more than a bay so you may not see what real installers see... But what we see isnt really what Liz thinks it is (IMO)..... Eddie Runner Of course we're also ignoring environmental damage (temperature cycling, dirt, ultraviolet light, moisture) as well. |
#42
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Physics of bridging an amplifier - was: Damping Material
"Kevin Murray" wrote:
"Nousaine" wrote: snip If the speaker "bottoms" meaning striking some part of the basket it is often already damaged. snip What do you mean by "striking some part of the basket?" I was referring to the motor assembly. I'm sure it's possible but I've yet to see a woofer damaged from a few whacks against the pole piece. I would think that if the diaphragm itself were to strike the basket, the damage would be assured and catastrophic. I'm thinking you mean whacks against the back plate. But yes I've encountered 2 models recently where the damage sounded simply like a rubbing voice coil and/or tinsel lead clicks but dissecting the driver revealed windings knocked off the rear of the former and a deformed former end. Tinsel leads hitting the cone are a clicking phenomenon. Cone hitting the basket is rare but seldom catastrophic; most cones will deform without permanent damage. In the catastrophic case we usually get a broken neck joint at the coil former/cone. The other possibilty is the spider hitting the basket; yes, its rare but there are some designs where this can happen. |
#43
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Physics of bridging an amplifier - was: Damping Material Question
Speakers are rated in watts in order to tell you how much electrical power
they can dissipate. Over 95% of the power delivered to a loudspeaker is dissipated as heat by it's resistive element and can quickly barbecue the voice coil. Reactive power (V-A) is what does all the work in a speaker. Since the reactive power is not converted to heat, the maximum V-A delivered to a speaker will vary depending on several things such as enclosure type, signal frequency, and driver x-max among others. In this case the driver will reach it's excursion limit and mechanically destroy itself. Since your average loudspeaker is only about 5% efficient at best, it's satisfactory to only provide it's maximum power rating in watts. If a speaker bottoms out it will sound like crap and the listener will turn down the volume. This inherent "built-in protection" protects the speaker from mechanical damage resulting from excessive V-A. 5%? You're being kind... |
#44
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Physics of bridging an amplifier - was: Damping Material Question
Since EVERYONE was against me, I
sometimes argued against 5 or 6 guys at the same time, it was overwhelming but I stuck it out and eventually won just about everyone over to the truth.... Yeah, but that's like heaven to you. |
#45
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Damping Material Question
No Ghee, you and Fred are morons. Do you not run a crossover on a sub? Are
you that dumb? Let's say you run your crossover unusually high at 140Hz, do you consider that high frequency? We are talking application here, not what a sub could potentially do in a lab if the conditions are right. Maybe he's talking about harmonics? But I think if you're getting harmonics of that amplitude and that frequency, standing waves are the least of your problems... |
#46
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Physics of bridging an amplifier - was: Damping MaterialQuestion
yes it was some of the most fun online I have ever had...
MZ wrote: Since EVERYONE was against me, I sometimes argued against 5 or 6 guys at the same time, it was overwhelming but I stuck it out and eventually won just about everyone over to the truth.... Yeah, but that's like heaven to you. |
#47
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Physics of bridging an amplifier - was: Damping Material Question
Like I said, "at best." You never know when someone has come up with a yet
unknown but more efficient design. I was covering my ass really. "MZ" wrote in message ... Speakers are rated in watts in order to tell you how much electrical power they can dissipate. Over 95% of the power delivered to a loudspeaker is dissipated as heat by it's resistive element and can quickly barbecue the voice coil. Reactive power (V-A) is what does all the work in a speaker. Since the reactive power is not converted to heat, the maximum V-A delivered to a speaker will vary depending on several things such as enclosure type, signal frequency, and driver x-max among others. In this case the driver will reach it's excursion limit and mechanically destroy itself. Since your average loudspeaker is only about 5% efficient at best, it's satisfactory to only provide it's maximum power rating in watts. If a speaker bottoms out it will sound like crap and the listener will turn down the volume. This inherent "built-in protection" protects the speaker from mechanical damage resulting from excessive V-A. 5%? You're being kind... |
#48
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Physics of bridging an amplifier - was: Damping Material Question
What's the most fun you've had online...?
"Eddie Runner" wrote: yes it was some of the most fun online I have ever had... |
#49
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Physics of bridging an amplifier - was: Damping MaterialQuestion
im not gonna say
Kevin Murray wrote: What's the most fun you've had online...? "Eddie Runner" wrote: yes it was some of the most fun online I have ever had... |
#50
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Physics of bridging an amplifier - was: Damping Material Question
My guess is it involves the name "Paris Hilton"...
-- Mark remove "remove" and "spam" to reply "Eddie Runner" wrote in message ... im not gonna say Kevin Murray wrote: What's the most fun you've had online...? "Eddie Runner" wrote: yes it was some of the most fun online I have ever had... |
#51
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Damping Material Question
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#52
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Damping Material Question
"MZ" wrote in Maybe he's talking about harmonics? But I think if you're getting harmonics of that amplitude and that frequency, standing waves are the least of your problems... I considered harmonics but came to basically the same conclusion that if you have harmonics that are that bad then something else is wrong. I also considered the source, Ghee, and thought that he probably doesn't even know what a harmonic is. Les |
#54
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Damping Material Question
(Scott Gardner) wrote:
On 25 Mar 2004 02:10:00 GMT, (Nousaine) wrote: "MZ" pam wrote: No Ghee, you and Fred are morons. Do you not run a crossover on a sub? Are you that dumb? Let's say you run your crossover unusually high at 140Hz, do you consider that high frequency? We are talking application here, not what a sub could potentially do in a lab if the conditions are right. Maybe he's talking about harmonics? But I think if you're getting harmonics of that amplitude and that frequency, standing waves are the least of your problems... In a 2600 ft3 room the standing wave region runs from 25-300 Hz. In a smaller car such as a Corvette, CRX, Acura Integra this is shifted up an octave to roughly 60-600 Hz. In a larger car it drops somewhat....but it's very common to have standing wave effects at 140 Hz in a vehicle. I think the standing waves discussion originally centered on whether you could find them *inside* an enclosure, and whether damping material would affect them. Whether or not they're present inside the vehicle, I think it's safe to say that the volume inside a subwoofer enclosure is so small as to preclude the formation of standing waves inside the box. Scott Gardner Agreed; standing waves at bass frequencies inside an enclosure are irrelevant to al but the largest enclosures....say 25 ft3. |
#55
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Damping Material Question
"thelizman" wrote in message
... Tha Ghee wrote: "thelizman" wrote in message ... are you saying there are no standing waves in sub encs.?? Not at subwoofer frequencies. Prove me wrong. yes there are, if there were not then what's the purpose of fiberfill, to reduce standing waves, and make the enc. seem bigger. show me data where there are no standing waves in enc. since you're all knowing. |
#56
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Damping Material Question
"Les" wrote in message
m... "Tha Ghee" wrote in message if you have a metal cone sub there can be hi-freq content. look at the lab graphs, so he's not a moron you may be. No Ghee, you and Fred are morons. Do you not run a crossover on a sub? Are you that dumb? Let's say you run your crossover unusually high at 140Hz, do you consider that high frequency? We are talking application here, not what a sub could potentially do in a lab if the conditions are right. Les were are not morons, there are subs that you can run without x-overs were talking concepts that's why I mentioned this. |
#57
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Damping Material Question
"Nousaine" wrote in message
... "MZ" pam Maybe he's talking about harmonics? But I think if you're getting harmonics of that amplitude and that frequency, standing waves are the least of your problems... In a 2600 ft3 room the standing wave region runs from 25-300 Hz. In a smaller car such as a Corvette, CRX, Acura Integra this is shifted up an octave to roughly 60-600 Hz. In a larger car it drops somewhat....but it's very common to have standing wave effects at 140 Hz in a vehicle. if you look at the graphs of some subs they can play up to 2k or so. |
#58
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Damping Material Question
In a 2600 ft3 room the standing wave region runs from 25-300 Hz. In a
smaller car such as a Corvette, CRX, Acura Integra this is shifted up an octave to roughly 60-600 Hz. In a larger car it drops somewhat....but it's very common to have standing wave effects at 140 Hz in a vehicle. if you look at the graphs of some subs they can play up to 2k or so. The primary breakup mode of most subs are much much lower than that. There may be a few that could play up high (maybe some of those aluminum jobs?), but the impedance is often much higher up there. Got any examples of subs that don't break up until 2kHz and still have a reasonably low impedance there? |
#59
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Damping Material Question
"Tha Ghee" wrote in message were are not morons, there are subs that you can run without x-overs were talking concepts that's why I mentioned this. Why would you want to run the sub without a crossover? We are not talking conepts here, we are talking what is actually going to happen in the vehicle. The OP asked a "what will this actually do?" type question and you respond, in your broken english, with some theory that could potentially happen, maybe, if you are a MORON and don't know how to setup a subwoofer system. Les |
#60
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Damping Material Question
"MZ" wrote in message
... In a 2600 ft3 room the standing wave region runs from 25-300 Hz. In a smaller car such as a Corvette, CRX, Acura Integra this is shifted up an octave to roughly 60-600 Hz. In a larger car it drops somewhat....but it's very common to have standing wave effects at 140 Hz in a vehicle. if you look at the graphs of some subs they can play up to 2k or so. The primary breakup mode of most subs are much much lower than that. There may be a few that could play up high (maybe some of those aluminum jobs?), but the impedance is often much higher up there. Got any examples of subs that don't break up until 2kHz and still have a reasonably low impedance there? The Aura Force 10s and Dynaudio |
#61
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Damping Material Question
"Les" wrote in message
... "Tha Ghee" wrote in message were are not morons, there are subs that you can run without x-overs were talking concepts that's why I mentioned this. Why would you want to run the sub without a crossover? We are not talking conepts here, we are talking what is actually going to happen in the vehicle. The OP asked a "what will this actually do?" type question and you respond, in your broken english, with some theory that could potentially happen, maybe, if you are a MORON and don't know how to setup a subwoofer system. Les if you read most CA mags they say you can run certain subs without a x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? |
#62
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Damping Material Question
Which dynaudio?
-- Mark remove "remove" and "spam" to reply "Tha Ghee" wrote in message ... "MZ" wrote in message ... In a 2600 ft3 room the standing wave region runs from 25-300 Hz. In a smaller car such as a Corvette, CRX, Acura Integra this is shifted up an octave to roughly 60-600 Hz. In a larger car it drops somewhat....but it's very common to have standing wave effects at 140 Hz in a vehicle. if you look at the graphs of some subs they can play up to 2k or so. The primary breakup mode of most subs are much much lower than that. There may be a few that could play up high (maybe some of those aluminum jobs?), but the impedance is often much higher up there. Got any examples of subs that don't break up until 2kHz and still have a reasonably low impedance there? The Aura Force 10s and Dynaudio |
#63
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Damping Material Question
if you read most CA mags they say you can run certain subs without a
x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? You can. But that doesn't mean they're responsive that high. Also, getting back to the original topic, if you're trying to attenuate high frequencies by facing it away from the front, then why would you be concerned with standing waves? |
#64
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Damping Material Question
Tha Ghee wrote:
if you read most CA mags they say you can run certain subs without a x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? Without a crossover, it is not longer a subwoofer. Face it away from the front? As if high frequency sounds didn't reflect... ....just when I thought you couldn't get any more stupid, you surprise me. -- thelizman "I didn't steal the FAQ either" Before you ask a question, check the FAQs for this newsgroup at http://www.mobileaudio.com/rac-faq. It contains over a decade and a half of knowledge. teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/ teamROCS Car Audio News http://www.teamrocs.com/news/ "It's about the music, stupid" This post is Copyright (C) 2004. Reproduction of its content anywhere other than usenet without the express written permission of the author is forbidden. |
#65
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Damping Material Question
"MZ" wrote in message
... Which dynaudio? -- Mark remove "remove" and "spam" to reply the 8" & 10" went up the mid 1khz, and if memory servers me correctly the review said you could use them in a 2 way system in a pinch. |
#66
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Damping Material Question
"MZ" wrote in message
... if you read most CA mags they say you can run certain subs without a x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? You can. But that doesn't mean they're responsive that high. Also, getting back to the original topic, if you're trying to attenuate high frequencies by facing it away from the front, then why would you be concerned with standing waves? Those are two different topic, standing waves and high freq. are not what I discussing, just that some subs can play high freq. that's all. |
#67
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Damping Material Question
"thelizman" wrote in message
... Tha Ghee wrote: if you read most CA mags they say you can run certain subs without a x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? Without a crossover, it is not longer a subwoofer. Face it away from the front? As if high frequency sounds didn't reflect... ...just when I thought you couldn't get any more stupid, you surprise me. -- thelizman "I didn't steal the FAQ either" Before you ask a question, check the FAQs for this newsgroup at http://www.mobileaudio.com/rac-faq. It contains over a decade and a half of knowledge. teamROCS Car Audio Forums http://www.teamrocs.com/caraudio/ teamROCS Car Audio News http://www.teamrocs.com/news/ "It's about the music, stupid" This post is Copyright (C) 2004. Reproduction of its content anywhere other than usenet without the express written permission of the author is forbidden. so just because it has no outside filtering it changes what it is, explain this to me?? they do but they will get absorbed more easily then low freq. content. not as much as you do, I didn't know someone could spout this much crap and no one call them on it. |
#68
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Damping Material Question
You brought up high frequencies to demonstrate that standing waves can be an
issue. So the two are inseparable. My question stands: if you're trying to attenuate high frequencies by turning the driver around, why would you be concerned with standing waves? -- Mark remove "remove" and "spam" to reply "Tha Ghee" wrote in message ... "MZ" wrote in message ... if you read most CA mags they say you can run certain subs without a x-over just face it away from the front. ok Les and you're so eloquent can I be like you when I'm near 80?? You can. But that doesn't mean they're responsive that high. Also, getting back to the original topic, if you're trying to attenuate high frequencies by facing it away from the front, then why would you be concerned with standing waves? Those are two different topic, standing waves and high freq. are not what I discussing, just that some subs can play high freq. that's all. |
#69
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Damping Material Question
"MZ" wrote in message
... You brought up high frequencies to demonstrate that standing waves can be an issue. So the two are inseparable. My question stands: if you're trying to attenuate high frequencies by turning the driver around, why would you be concerned with standing waves? -- standing waves have nothing to do with high freq. if I said that it was a mistake. |
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