What is stopping the ultimate?

Tacs. There is a lot of truth in what you say.

Why such direct things are not done is a wonder to me. Seems you like to think about these things. Answer this for me. Amp makers always measure distortion as voltage amplitude distortion , almost exclusively. It's almost all they care about - using negative feedback ect... But a driver-transducer is current controlled. Most amp makers never worry about this. It's important because the current in the driver's coil is going to be the output voltage divided by the speaker's impedance right(ohm's law)? This means that as the speaker's impedence fluctuates all over the place (with frequency and voice coil temperature) the current does too. Current will only be linearly related to output voltage if the speaker presents a purely resistive load which it never does. Anyway, the impedence fluctuations translate directly into distortion of the current driving the coil. To me this is why you get so many amps that sound crappy with certain speakers. Do you get what I mean? I like to make speakers as a hobby and i have always wondered on this point. It seems the amp people are so focused on one thing they fail to see what is important to the speaker-current. I do not see it even discussed. I believe you would have to raise the amp's output impedence to deliver more consistent current. Tell me what I'm missing.. as I said I just like to mess with speakers and am not an EE or anything.

Sincerely, I remain

Clueless,

I agree with you.

Many of the amp vendors do actually talk about current. At the low-end of hi-fi (where I and my budget reside!) talking about "high-current" designs and providing at least sketchy numbers (very sketchy) to partially back it up is pretty standard practice.

They do this to distinguish themselves from the JVCs of the world that are doing 5x100WPC home theatre receivers with well under 1% THD, for under $300. All in a box that weighs about 10 pounds.

I don't think they (the low-end of high-end) feel the need to provide more detailed current numbers than they do (mainly just amp ratings, with no associated information), because very few people ask about it.

I'm thinking of Rotel, NAD Silver Series, and the like. May also be true at the higher-end.

- Eric

Ehart. I'm not talking just about the amp's ability to throw out current in my post but I agree with you totally. Power (in watts) is voltage times current and you need both. Current is needed when the load goes low. I agree with you as far as you go.

But I am talking about another issue in addition. Providing STEADY current into a varying load (the speaker) which gets very little attention as far as I can tell. Amp folks talk a lot about steady voltage output and the speaker coil is a current issue which should be kept constant as possible. This is true even with high end stuff. When you do hear about current it's always this artifical discussion about an amp running into a resistive load. I may just not understand something. That is why i'm throwing it out for discussion. Some of the smaller set amps drive really effecient speakers with inherent damping and avoid the current issue talked about in the post above .. at least to greater degree than the high powered amps.. Maybe one of the reasons they sound better?

Sincerely, I remain

The amount of money that some folks are able and willing to expend on this hobby these days always makes me wonder why the high-end industry stops short of trying to exceed the present paradigm of reproduced sound. It seems to me that instead of wringing hands and waiting to see what new digital format or channel configuration will prevail in the battles of the big boys - who aren't selling their products based on audiophile criteria - the high-end could form an industry consortium of their own to originate a perfectionist approach to recording, software, and system parameters that could be adopted by audiophiles and the high-end industry alone. Yes, such an effort would be very expensive, as would the resulting hardware and recordings. It would also have to be backward-compatible in some way with existing formats and software. But given the amounts of cash that some of us are apparently ready to throw at mere refinements of old technology and tweaks that don't significantly advance the illusion of recreating the original performance, and the prices that are already paid for vintage records of audiophile interest, I can imagine such an all-out assault actually reinvigorating the business. In general, the new paradigm would focus on completely integrated systems (forget the separate components, mix-'n'-match approach), be multi-channel and all-digital in nature, and would require purpose-built dedicated listening environments (the answer to the thrust of the original question is the listening room, by the way - on par with software and above speakers). The recording process would be an integral part of this system, utilizing a purist audiophile-grade chain and agreed-upon microphone techniques to enable predictable multi-channel reproduction. The digital recording and storage media and all signal proccessing would have to be accomplished using a data density exceeding theoretical distortion and detection limits of electronics and the human ear. The number of discrete audio channels would be determined solely by what is acoustically required for transparent soundfield immersion (my own guess is eight, minimum). Maybe the system would even run off of a dedicated, high-power utility line incompatible with other household devices. Whatever it takes. And whatever it may be - whether a complete room/system cost a million dollars and recordings cost hundreds each - I bet that buyers would come forth and ante up. Such is the power of music (and money). And the rest of us mortals would still have what we've got today. (But I, for one, would not feel much the poorer for it, since I primarily listen to vintage records and reissues from the golden ages of rock and roll, DIY punk, studio pop, jazz, rhythm and blues, etc., where the signature [read: distorted] sound of the recording [analog and often mono] and the medium [often less than pristine] is as important to the atmosphere of the record as the performance itself!)

Clueless (who isn't) smacks the nail right on the head. The electrical interaction between the amplifier and the speaker is wayyyy complex and cannot be deduced from reading the spec sheets of both. You have to do it with your ears. That's why amps with very similar measured characteristics sound so strikingly different when connected to the same speakers and why speakers sound so very different when connected to the same amp.

I wouldn't say that at some point in the future these matters couldn't be measured and quantified but at this point we've only got one way to do it....with the ears.