I have this theory., no wait, I postulate that....

[stehno]

... the only possible means to achieve any higher level of performance can be done by only 1 and/or 2 possible objectives:

1. Improved efficiencies.

2. Lowered resistance.

How wrong am I with this and why?

 

[Folsom]

Extremely, Wrong.

Efficiency of what? Why would it matter? Maybe the least efficient is best. With enough power efficiency is irrelevant. It's about preferance and sometimes the pocketbook.

Resistance is similar. While resistance is bad for shields, it's not necessarily anywhere else. Haven't you ever noticed lots of resistors are used in every single design there is? Often you need resistance in locations to make a device more powerful.

I haven't a clue how this as a topic is anything but non-sense.

 

[es347]

... the only possible means to achieve any higher level of performance can be done by only 1 and/or 2 possible objectives:

1. Improved efficiencies.

2. Lowered resistance.

How wrong am I with this and why?

..ok I give up? What's the punch line?

 

[CGabriel]

... the only possible means to achieve any higher level of performance can be done by only 1 and/or 2 possible objectives:

1. Improved efficiencies.

2. Lowered resistance.

How wrong am I with this and why?

If history proves anything it is that human creativity and innovation are unlimited.

 

[Robh3606]

Efficiency of what? Why would it matter? Maybe the least efficient is best. With enough power efficiency is irrelevant. It's about preferance and sometimes the pocketbook.

Hello Folsom

Well speaker efficiency can make a huge difference depending on your goals. In the real world loudspeaker power handling is a real issue. Just because you have a 10,000 watt amp is pretty much mealiness as all drivers have very real power handling issues. What you want is a combination of efficiency and power handling that are compatible with your SPL goals. Easiest way to get there is higher efficiency speakers as that lowers distortion across the rest of the system. Ideally you want as much clean headroom as you can muster and the only way to do that is higher efficiency speakers. I have a full 30db of headroom over my average mid 80 db listening levels because my mains are 98db 1 watt. All of my drivers are all well under their max power ratings, my amps are running at only a couple of watts so the whole system is operating in its sweet spot.

Rob

 

[853guy]

... the only possible means to achieve any higher level of performance can be done by only 1 and/or 2 possible objectives:

1. Improved efficiencies.

2. Lowered resistance.

How wrong am I with this and why?

Interesting, Steno. My answer is: It depends.

Let’s take the Tesla Model S.

It’s estimated it has a battery-to-wheel efficiency of about 68%. That’s versus a tank-to-wheel efficiency for a conventional combustion engine of about 16%. And in terms of performance (acceleration and emissions), it’s clear the Tesla is a ‘better’ performing car.

But, it doesn’t take into account the medium needed to store the energy. Because while the Tesla uses 320 Wh/mile of energy (85kWh for a total range of 265 miles) and a gasoline-powered car (averaging 35mpg) uses 940 Wh/mile of energy (33kWh for a total range of 35 miles for one gallon of fuel) - the efficiency advantage clearly in the Tesla’s favour - the weight/size penalty the batteries comprise limits the distance one can travel significantly in real-world terms. That is, you can fill up the Tesla’s battery all you want, but you’re only ever going to get 265 miles out of it compared to what can be done if one fills a conventional combustion-powered car’s tank all the way to the top.

So if ‘performance’ relative to efficiency is judged solely in terms of acceleration and emissions, we have a clear winner. If we include real-world range, it becomes slightly more amorphous.

There’s no doubt an electric motor is more ‘efficient’ than a car (maximum efficiency for a diesel-engined car can approach 20%), a high performance vehicle like an F1 car (up to 50%), or indeed a rocket engine (around 70%), but there’s a reason long-haul commercial airliners aren’t outfitting their airframes with electric engines just yet.

So, y’know, efficiency is one thing, performance another. Like I say, it depends.

 

[Folsom]

..ok I give up? What's the punch line?

I believe there is a joke section of the forum...

Robh3606

Sure you can hit thermal limitations. And like I said, sometimes the expensive of inefficiency can climb into the stratosphere, but we already have efficient speakers.... so?

 

[NorthStar]

The more details you can provide the closer your answers. :b

 

[RogerD]

Is he talking about current resistance or signal resistance? System efficiency?

The lower the signal resistance the greater the purity of the signal...which in turn means the system efficiency is improved. Just my thoughts.

 

[Folsom]

Um, no. You need input impedance to be high enough that your preamp can drive it (and well). Therefore signal resistance is anything but low at the amp. It should be low at the source, or preamp output. The ground however should be as low as possible.

Purity goes down, substantially, when the amp has low impedance.

Current resistance isn't as big of a deal as people think either. Half the time people are trying to overcome a problem by making the power supply cables/cap plates enormous. A resistor doesn't actually slow it down or anything like that. But if calculated wrong then the power supplies transformer may not be large enough, or high enough voltage. Efficiency drops with resistance, but ironically (not really but it sounds like it) some resistance may make the circuit actually provide substantially better current delivery by stopping unwanted current from being stored on the circuit.

 

[the sound of Tao]

Stehno,
I'm figuring you probably have all your postules at the ready to fire out in defence of this proposition so it may be more fully postulated by us all.

I sense a little Machiavellian stirring but do find it kind of interesting to see what we might learn from this and as usual hoping it is a fruitful thing.

Would it be helpful to better define 'any higher level of performance'... Since 'any' is by any standards quite a small margin.

Also are you intending this to be only 'objectively' higher performance and with only measurable levels of performance evaluated and then some guide to that criteria.

If not, I am wondering how are you are going to deal with any subjective appreciation of higher levels of performance. Given the relative impossibility to account for everyone's perception as to better performance, this will be a sticky point if you don't box out subjective gains.

Also do you intend 'improved efficiencies' to be quite specific wrt speaker efficiency or do you mean this to be a virtually open definition that can be used to cover just about any perceived or measured improvement eg improved efficiencies in noise reduction, or improved efficiencies in component to component noise shielding, or improved efficiency in current response or resonance management etc.

And with regards to 'resistance' is your response then going to be so irresistible as to make all current resistance to your position futile... Hoping not, looking forward to this landing with the butter on the upside.

 

[stehno]

Interesting, Steno. My answer is: It depends.

Let’s take the Tesla Model S.

It’s estimated it has a battery-to-wheel efficiency of about 68%. That’s versus a tank-to-wheel efficiency for a conventional combustion engine of about 16%. And in terms of performance (acceleration and emissions), it’s clear the Tesla is a ‘better’ performing car.

But, it doesn’t take into account the medium needed to store the energy. Because while the Tesla uses 320 Wh/mile of energy (85kWh for a total range of 265 miles) and a gasoline-powered car (averaging 35mpg) uses 940 Wh/mile of energy (33kWh for a total range of 35 miles for one gallon of fuel) - the efficiency advantage clearly in the Tesla’s favour - the weight/size penalty the batteries comprise limits the distance one can travel significantly in real-world terms. That is, you can fill up the Tesla’s battery all you want, but you’re only ever going to get 265 miles out of it compared to what can be done if one fills a conventional combustion-powered car’s tank all the way to the top.

So if ‘performance’ relative to efficiency is judged solely in terms of acceleration and emissions, we have a clear winner. If we include real-world range, it becomes slightly more amorphous.

There’s no doubt an electric motor is more ‘efficient’ than a car (maximum efficiency for a diesel-engined car can approach 20%), a high performance vehicle like an F1 car (up to 50%), or indeed a rocket engine (around 70%), but there’s a reason long-haul commercial airliners aren’t outfitting their airframes with electric engines just yet.

So, y’know, efficiency is one thing, performance another. Like I say, it depends.

Interesting perspective, 853guy. So I assume you're conditionally in agreement with my OP?

Assuming your stats are accurate, you go on to say, "the weight/size penalty the batteries compromise the distance one can travel." However, you neglected to mention a few other things such as drag coefficient, aerodynamics, passenger load, etc, all of which influence the Tesla's total range of approximately 265 miles.

So applying my improved efficiencies and lowered resistance philosophies, what might happen to the Tesla's total mileage range if Tesla:

1. improves the Model S' aerodynamics by 15%?

2. swaps in all wiring and armatures with superior cryogenically-treated wiring?

3. reduces the Model S' GVW by 15%?

4. designs a new battery of same power potential but reduces size by 15% and weight by 15%?

5. swaps out the current model tires with a new tire tread design that reduces drag coefficient by 15%?

Given the Tesla Model S' current performance state verses these hypothetical (but potentially real) improved efficiencies and reduced resistances what do you suppose would happen to the Model S' total driving range per charge? Also, what might these hypothetical changes do to car's 0-60 performance, lateral acceleration, and stopping abilities?

 

[853guy]

Interesting perspective, 853guy. So I assume you're conditionally in agreement with my OP?

Assuming your stats are accurate, you go on to say, "the weight/size penalty the batteries compromise the distance one can travel." However, you neglected to mention a few other things such as drag coefficient, aerodynamics, passenger load, etc, all of which influence the Tesla's total range of approximately 265 miles.

So applying my improved efficiencies and lowered resistance philosophies, what might happen to the Tesla's total mileage range if Tesla:

1. improves the Model S' aerodynamics by 15%?

2. swaps in all wiring and armatures with superior cryogenically-treated wiring?

3. reduces the Model S' GVW by 15%?

4. designs a new battery of same power potential but reduces size by 15% and weight by 15%?

5. swaps out the current model tires with a new tire tread design that reduces drag coefficient by 15%?

Given the Tesla Model S' current performance state verses these hypothetical (but potentially real) improved efficiencies and reduced resistances what do you suppose would happen to the Model S' total driving range per charge? Also, what might these hypothetical changes do to car's 0-60 performance, lateral acceleration, and stopping abilities?

The reason I specifically used the Tesla was the fact that it’s not theoretical. It’s a real-world concept brought to life with all the inherent compromises present and accounted for. Once we go beyond real-world scenarios it opens up an avenue for dialogue in which realities become stretched beyond the point of truthfulness. Why stop at 15%? While we’re imagining it, why not talk about a new battery design that reduces size and weight by 1000% and never needs to be recharged?

Nevertheless, because you took the time to respond, let’s look at the real-world implications of your suggestions above:

1. Decreasing the CD of a car by 15% has the potential to negatively impact on cooling, packaging, visibility, safety, increased lift at high speed and be more susceptible to sidewinds and instability during high-speed manoeuvres.

2. Added cost, complexity, compliance issues, extended testing, supplier demands.

3. Decreasing a car’s weight by 15% is likely to come through an extensive remanufacture of the car’s chassis and electronics the same way any car 'loses' weight. Aside from the complexity involved, it also has the potential to increase the use of more expensive and labour intensive materials (carbon fibre, magnesium, titanium), decrease the power/range through the use of smaller/lighter batteries, impact negatively on packaging, sound deadening, and luxury features, and decrease the car’s crash-resistance and safety cell.

4. I’m no expert of battery technology. In fact, I’m no expert on anything. But any new battery that can deliver the same power potential but with reduced size and weight has the potential to not only be more expensive to produce, but have negative impact on cooling, charging time, current demands, fuse technology, and yes, total mileage range (any smaller, lighter battery that can deliver the same power is likely to be able to deliver it for a shorter period of time).

5. Reducing the drag coefficient of any tire for any vehicle will result in a negative impact on maximum speed rating, handling and braking distance, and potentially negatively impact ride comfort, puncture resistance and wet-weather performance.

Again, I’m not quite sure where you’re going with all this. Aren’t the answers to your questions obvious? It depends. The fact of the matter is that there’s no free lunch. Efficiencies are ultimately compromises weighed against positive/negative payoffs. You can apply theoretical efficiencies of any amount you want but unless you’re prepared to consider the potential downsides it’s a discussion existing in a vacuum of your own imagination.