ZED says running @ 1 ohm is dumb

[lucas569 10+ year member]

Zed also said that full range Class D sucked. Care to guess what topology his latest amplifiers are? Full range Class D.

im sure hell have some smart reason for that and the zed fanboys will bow down

 

[audioholic 5,000+ posts]

that's because your sub isn't efficient enough to get full excursion from the power your amp puts out at 4ohm.
the main point is efficiency, but that is a concept of yesteryear. It has been pretty much thrown out the window since 2002 or so

You make it sound like an efficient subwoofer is a lost technology. The car audio industry has shifted away from higher efficiency subs for a very good reason... Hoffman's Iron Law, which states . Those higher sensitivity subs of yesteryear also required much larger enclosures than do the lower efficiency subs of today. With amplifiers getting larger, watts getting cheaper, and cars getting smaller all the time, its a natural trend for the speaker industry to stray away from large enclosure, higher efficiency drivers.
Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

And in fact, running at a lower impedance for increased output capability from the amplifier, and then adjusting your gains artificially low, is superior to running at a lower impedance and setting your gains at their 'proper' position. Why? 'Headroom' for dynamics.

Just because someone is good at designing amplifiers does not make his theories on everything car audio related true, obviously.

 

[lucas569 10+ year member]

You make it sound like an efficient subwoofer is a lost technology. The car audio industry has shifted away from higher efficiency subs for a very good reason... Hoffman's Iron Law, which states . Those higher sensitivity subs of yesteryear also required much larger enclosures than do the lower efficiency subs of today. With amplifiers getting larger, watts getting cheaper, and cars getting smaller all the time, its a natural trend for the speaker industry to stray away from large enclosure, higher efficiency drivers.
Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

And in fact, running at a lower impedance for increased output capability from the amplifier, and then adjusting your gains artificially low, is superior to running at a lower impedance and setting your gains at their 'proper' position. Why? 'Headroom' for dynamics.

Just because someone is good at designing amplifiers does not make his theories on everything car audio related true, obviously.

very well put!

 

[thericanballer 10+ year member]

You make it sound like an efficient subwoofer is a lost technology. The car audio industry has shifted away from higher efficiency subs for a very good reason... Hoffman's Iron Law, which states . Those higher sensitivity subs of yesteryear also required much larger enclosures than do the lower efficiency subs of today. With amplifiers getting larger, watts getting cheaper, and cars getting smaller all the time, its a natural trend for the speaker industry to stray away from large enclosure, higher efficiency drivers.
Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

And in fact, running at a lower impedance for increased output capability from the amplifier, and then adjusting your gains artificially low, is superior to running at a lower impedance and setting your gains at their 'proper' position. Why? 'Headroom' for dynamics.

Just because someone is good at designing amplifiers does not make his theories on everything car audio related true, obviously.

you ALWAYS have great informative posts. and theyre always really long. lol. but good tho. i like this thread ive learned a lot actually.

 

[RJesus 10+ year member]

You make it sound like an efficient subwoofer is a lost technology. The car audio industry has shifted away from higher efficiency subs for a very good reason... Hoffman's Iron Law, which states . Those higher sensitivity subs of yesteryear also required much larger enclosures than do the lower efficiency subs of today. With amplifiers getting larger, watts getting cheaper, and cars getting smaller all the time, its a natural trend for the speaker industry to stray away from large enclosure, higher efficiency drivers.
Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

And in fact, running at a lower impedance for increased output capability from the amplifier, and then adjusting your gains artificially low, is superior to running at a lower impedance and setting your gains at their 'proper' position. Why? 'Headroom' for dynamics.

Just because someone is good at designing amplifiers does not make his theories on everything car audio related true, obviously.

The mystic holy aura that zed puts off must have confused me.

But he mentions that theres about a 4db difference between 4 ohm and 1 ohm, and only a 2 db difference between 2 ohm and 4 ohm. So obviously at higher ohm's that gap will be greater. I think there might be a trade-off point where efficiency and db gain are both at high levels compared to the extreme ohm levels. Its probably either 2 or 4 lol, but thats just a huge guess. Of course this would be amplifier-specific.

and zed says headroom is bad //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

To some a half filled glass of water is half empty, to others it is half full.

To the engineer, the glass is twice as big as it needs to be.

That leads me to believe that if an amplifier 'needs' headroom to have dynamics, then it isn't designed very well.

It's sensitivity, not efficiency, but you definitely have the right idea. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif
If a sub running at 4 Ohms takes 1 watt to reach a given volume level, the same sub at 2 Ohms will need 2 watts to reach the same level and so on. As no amplifier acts as a perfect voltage source, one is better off running the driver at the higher impedance.

Why aren't there more efficient subs out today?

I would think that in addition to Hoffman's Iron Law,

efficiency, low frequency extension, small enclosure... pick two>.

One could add that a smaller sub would warrant a smaller enclosure, while still being able to maintain low hz and efficiency.

In other words, Rather than having an efficient version of the dc lvl 5 in a box bigger than a car, can't you have an efficient version of a dc lvl 3 in a smaller box? (smaller than the size of a car).

I guess I'd need to know the point in which a 'regular' sized box meets dc lvl x

hopefully its not a dc lvl 0.5 lol.

then that dc lvl 0.5 would be pretty cheap to make, and because of its huge efficiency levels, would be equal to like a dc lvl 3, right?

 

[J31Rob 5,000+ posts]

Zed >

 

[gunz4me2 10+ year member]

im sure hell have some smart reason for that and the zed fanboys will bow down

He pulled the "recent advances in technology" BS reason as to why 12 volt, full range Class D can now sound just as good as Class AB. I guess the Zed fanbois are lapping it up as the gospel.//content.invisioncic.com/y282845/emoticons/rolleyes.gif.c1fef805e9d1464d377451cd5bc18bfb.gif

 

[thegreatestpenn 5,000+ posts]

You make it sound like an efficient subwoofer is a lost technology. The car audio industry has shifted away from higher efficiency subs for a very good reason... Hoffman's Iron Law, which states . Those higher sensitivity subs of yesteryear also required much larger enclosures than do the lower efficiency subs of today. With amplifiers getting larger, watts getting cheaper, and cars getting smaller all the time, its a natural trend for the speaker industry to stray away from large enclosure, higher efficiency drivers.
Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

And in fact, running at a lower impedance for increased output capability from the amplifier, and then adjusting your gains artificially low, is superior to running at a lower impedance and setting your gains at their 'proper' position. Why? 'Headroom' for dynamics.

Just because someone is good at designing amplifiers does not make his theories on everything car audio related true, obviously.

The only thing of value you just said is basically there is a trade-off, either high efficiency and low power with big enclosures or low efficiency with high power and small enclosures.

i think both extremes have their uses, but most people need to be in the middle somewhere. As much as I loved the old school stuff, class a technology sucks current like a mutha. On the other end I love boasting about how big my 3500wrms monoblock amp is, but i can barely fit it in my little civic, let alone subs that can handle it.

Its all about the trade-off

 

[Johnny Law.Lulz 5,000+ posts]

Just reading the first page of this thread.

I noticed a guy saying his nightshade is louder to the ear at 1 ohm rather than 4 on his 3K. But that is also manipulated by your box. Your box is built to specifications at running that woofer at RMS or higher, but you dont know the specs for lower than RMS. Im sure someone could get your nightshade louder than you would think off of 500 or so RMS but it would be a big *** box.

I wonder if you can hear the difference in JL's amps since some of them do the same power at all ohm loads, considering he is talking about the power, i think someone should get one of those or try this and wire it up and listen to ohm load differences.

I also wonder if running a 2 channl at 4 ohm bridged would sound better than 1 or 2 ohm mono.

The standard of high ohm load sounds better is a purely SQ thing though which seems to have already been established in this thread.

 

[thegreatestpenn 5,000+ posts]

I also wonder if running a 2 channl at 4 ohm bridged would sound better than 1 or 2 ohm mono.

depends on the brand, some of the most beautifully sounding amps I've had are rf power series amps and the mono amps crushed all others I used in terms of clean bass (and still got loud). But this audiopipe amp I'm using now is only louder than my tiny 200wrms@4ohm 2channel when set over 1000wrms@1ohm so

 

[Pyro_By_Nature 5,000+ posts]

Zed's comments are way too general to take seriously. If we were to apply his logic thoroughly, its stupid to run an amp at 4ohms, because the difference in output from it at 4ohms versus 8ohms is negligible. Consequently, its stupid to run an amp at 8ohms, since the difference in output between it and running at 16 ohms is approx the same as going from 4 ohms to 8. And, its stupid to run at 16 ohms instead of 32 ohms... Get my point?

I haven't been on this forum in a while, but sure enough you're still spitting more hypothetical babble, big surprise //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[audioholic 5,000+ posts]

There is a lot of confusion in this thread. Let me try to sort through some of it for you guys.

The mystic holy aura that zed puts off must have confused me.But he mentions that theres about a 4db difference between 4 ohm and 1 ohm, and only a 2 db difference between 2 ohm and 4 ohm. So obviously at higher ohm's that gap will be greater. I think there might be a trade-off point where efficiency and db gain are both at high levels compared to the extreme ohm levels. Its probably either 2 or 4 lol, but thats just a huge guess. Of course this would be amplifier-specific.

and zed says headroom is bad //content.invisioncic.com/y282845/emoticons/confused.gif.e820e0216602db4765798ac39d28caa9.gif

To some a half filled glass of water is half empty, to others it is half full.

To the engineer, the glass is twice as big as it needs to be.

That leads me to believe that if an amplifier 'needs' headroom to have dynamics, then it isn't designed very well.

Why aren't there more efficient subs out today?

I would think that in addition to Hoffman's Iron Law,

One could add that a smaller sub would warrant a smaller enclosure, while still being able to maintain low hz and efficiency.

In other words, Rather than having an efficient version of the dc lvl 5 in a box bigger than a car, can't you have an efficient version of a dc lvl 3 in a smaller box? (smaller than the size of a car).

I guess I'd need to know the point in which a 'regular' sized box meets dc lvl x

hopefully its not a dc lvl 0.5 lol.

then that dc lvl 0.5 would be pretty cheap to make, and because of its huge efficiency levels, would be equal to like a dc lvl 3, right?

Zed's db difference is in reference to using an amplifier example that does not double power going from 4ohms to 2ohms. That is specific to the design of the amplifier he's using for an example, not the norm. The laws of physics tell us that halving resistance doubles the work produced, given a specific amount of energy exerted. This only changes when the amplifier design, for various reasons, alters this otherwise normal energy to work relationship (another example is the slash series of amps from JL who produce the same power in a range of resistances/impedance, again due to the design). Which does not alter the law of physics dictating energy in versus work created, the design difference merely alters the amount of energy the platform/design will input and amplify. In short, he is 'stacking the deck' to try and bolster his theory. Power compression will increase as power output to the the speaker(s) increases, but that is an outside factor not relating directly to the discussion of amplifier performance based on impedance.
As to his comments on headroom, well he lives in a perfect world where an amplifier can handle any dynamic signal variance under any circumstance. Ironic really, considering he is also the same person telling us its futile to run your amplifier at its lowest rated impedance. If an amplifier has sufficient 'headroom' built-in by design, there is absolutely no argument against running it at its lowest possible impedance. None.

And his black and white answer of the glass is twice as large as it needs to be, is simply more generalities that gloss over the complexity of reality. What is 'twice as full as it needs to be' in relation to audible compliance with signal dynamics? The answer: the difference is in the ear of the beholder. To one person, running an amplifier at its lowest possible impedance, and the gain set to its maximum allowable setting, gives acceptable performance in terms of dynamics. To another, more discerning ear, it does not. Which person is 'correct'? In Zed's world of black and white, only one of them can be. In reality, both are. SQ competitors world wide have accepted the idea of artificial 'headroom' in terms of overly large amplifiers, choked back via lowered gain settings, for dynamic headroom. According to Zed, they are all wrong. Are they? To the average enthusiasts, this level of performance is unnecessary. To the competitors, it can be the difference between a winning setup, and an average one, per their level of competition. Sure, if we were all millionaires, we could probably afford to pay for amplifiers with output stages built overly large to accommodate any reasonable dynamic variance in the signal voltage. In the real world, most amps are built to suit the average enthusiast, and a real-world increase in dynamic capability can be experienced from choking down an amp via artificially lowered gains and/or impedance levels of operation. Again, ironic that the man who claims running an amp at its lowest impedance level possible is unnecessary is the very same man who claims an amplifier should/does have the innate ability to handle all dynamic situations already built-in. He contradicts himself.

"One could add that a smaller sub would warrant a smaller enclosure, while still being able to maintain low hz and efficiency."

Smaller in what regard? You seem to be implying there is an additional factor outside the three specified factors Hoffman's Iron law discusses: speaker size. This is not the case. Efficiency, enclosure size, low frequency extension. These three factors are the trade-off, and only these three factors.

The only thing of value you just said is basically there is a trade-off, either high efficiency and low power with big enclosures or low efficiency with high power and small enclosures.
i think both extremes have their uses, but most people need to be in the middle somewhere. As much as I loved the old school stuff, class a technology sucks current like a mutha. On the other end I love boasting about how big my 3500wrms monoblock amp is, but i can barely fit it in my little civic, let alone subs that can handle it.

Its all about the trade-off

Im confused why you decided to judge the 'value' of what I said, then followed up with statements that seem to add little or nothing to the conversation, to be frank. The physical size of your amplifier has nothing to do with Hoffman's Iron Law, or the weight/size of your subwoofer. Its a trade-off between system efficiency (enclosure + speaker), enclosure size required for a desired frequency response, and low frequency extension characteristics. You relating that your overly large amplifier and huge subwoofers are a trade off to a smaller amp and higher efficiency sub, presumably in a larger enclosure, is merely a reflection of current technology and your choice of equipment. Not all 3500 watt amps are the same size, for example. Nor are all 1500 watt (rated) subwoofers the same size. But, Hoffman's Iron Law is an unwavering and unavoidable law of physics. Technology can and does alter amplifier sizes, 1000 watt amps of today are generally MUCH smaller than 1000 watt amps of, say, 15 years ago. Thanks to technological advances. But Hoffman's Iron Law remains exactly the same as it always has, and always will.

 

[audioholic 5,000+ posts]

I haven't been on this forum in a while, but sure enough you're still spitting more hypothetical babble, big surprise //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

You are welcome to post any evidence you have, for or against, absolutely anything I said. Or, you are welcome to imply Im wrong while giving absolutely no basis for your theory what so ever. Lets see which option you choose, shall we? //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[thegreatestpenn 5,000+ posts]

There is a lot of confusion in this thread. Let me try to sort through some of it for you guys.
Zed's db difference is in reference to using an amplifier example that does not double power going from 4ohms to 2ohms. That is specific to the design of the amplifier he's using for an example, not the norm. The laws of physics tell us that halving resistance doubles the work produced, given a specific amount of energy exerted. This only changes when the amplifier design, for various reasons, alters this otherwise normal energy to work relationship (another example is the slash series of amps from JL who produce the same power in a range of resistances/impedance, again due to the design). Which does not alter the law of physics dictating energy in versus work created, the design difference merely alters the amount of energy the platform/design will input and amplify. In short, he is 'stacking the deck' to try and bolster his theory. Power compression will increase as power output to the the speaker(s) increases, but that is an outside factor not relating directly to the discussion of amplifier performance based on impedance.

As to his comments on headroom, well he lives in a perfect world where an amplifier can handle any dynamic signal variance under any circumstance. Ironic really, considering he is also the same person telling us its futile to run your amplifier at its lowest rated impedance. If an amplifier has sufficient 'headroom' built-in by design, there is absolutely no argument against running it at its lowest possible impedance. None.

And his black and white answer of the glass is twice as large as it needs to be, is simply more generalities that gloss over the complexity of reality. What is 'twice as full as it needs to be' in relation to audible compliance with signal dynamics? The answer: the difference is in the ear of the beholder. To one person, running an amplifier at its lowest possible impedance, and the gain set to its maximum allowable setting, gives acceptable performance in terms of dynamics. To another, more discerning ear, it does not. Which person is 'correct'? In Zed's world of black and white, only one of them can be. In reality, both are. SQ competitors world wide have accepted the idea of artificial 'headroom' in terms of overly large amplifiers, choked back via lowered gain settings, for dynamic headroom. According to Zed, they are all wrong. Are they? To the average enthusiasts, this level of performance is unnecessary. To the competitors, it can be the difference between a winning setup, and an average one, per their level of competition. Sure, if we were all millionaires, we could probably afford to pay for amplifiers with output stages built overly large to accommodate any reasonable dynamic variance in the signal voltage. In the real world, most amps are built to suit the average enthusiast, and a real-world gain in dynamic capability can be experienced from choking down an amp via artificially lowered gains and/or impedance levels of operation. Again, ironic that the man who claims running an amp at its lowest impedance level possible is unnecessary is the very same man who claims an amplifier should/does have the innate ability to handle all dynamic situations already built-in. He contradicts himself.

"One could add that a smaller sub would warrant a smaller enclosure, while still being able to maintain low hz and efficiency."

Smaller in what regard? You seem to be implying there is an additional factor outside the three specified factors Hoffman's Iron law discusses: speaker size. This is not the case. Efficiency, enclosure size, low frequency extension. These three factors are the trade-off, and only these three factors.

Im confused why you decided to judge the 'value' of what I said, then followed up with statements that seem to add little or nothing to the conversation, to be frank. The physical size of your amplifier has nothing to do with Hoffman's Iron Law, or the weight/size of your subwoofer. Its a trade-off between system efficiency (enclosure + speaker), enclosure size required for a desired frequency response, and low frequency extension characteristics. You relating that your overly large amplifier and huge subwoofers are so how a trade off to a smaller amp and higher efficiency sub, presumably in a larger enclosure, is merely a reflection of currect technology and your choice of equipment. Not all 3500 watt amps are the same size, for example. Nor are all 1500 watt (rated) subwoofers the same size. but, Hoffman's Iron Law is an unwavering and unavoidable law of physics. Technology can and does alter amplifier sizes, 1000 watt amps of today are generally MUCH smaller than 1000 watt amps of, say, 15 years ago. Thanks to technological advances. But Hoffman's Iron Law remains exactly the same as it always has, and always will.

you've talked a lot and added nothing either, just tried to critique most post. how about you provide some real world evidence. what testing have you done? what personal examples do you have? I've said multiple examples and you are only talking about a law that is only ideal at best

 

[audioholic 5,000+ posts]

you've talked a lot and added nothing either, just tried to critique most post. how about you provide some real world evidence. what testing have you done? what personal examples do you have? I've said multiple examples and you are only talking about a law that is only ideal at best

Your argument makes no sense. How would you like me to prove Hoffman's Iron Law to you? And for what purpose exactly? What examples have you provided that alter anything I said? You are just being contrary and argumentative imo.