How do TINY speakers produce such BIG sound?

Paradoxically, it seems to me that these devices with the micro speaker have no space for anything like a horn. There is just a micro speaker and it is stuck to the iner surface of the hard plastic casing which has a series of seemingly inadequate perforations.

What exactly is a nano driver?

Google does not comes up much apart from the name of some Nano iPod and its software drivers. Or sets of golf clubs!

Alex Coleman wrote in news:Xns97C07183CDF9A71F3M4@127.0.0.1:

Exactly. :) While the sealed baffle is NOT the most efficient, at all, it does extend the bass response. If the case shell is hard enough, and the driver has a neodymium iron boron magnet (as is likely at that small size to increase efficiency), then the smaller the airflow through the case, the stronger the bass. I mentioned in another post the use of pulsed energy, compressing the sound such that the decays are more abrupt than usual, falling to a lower level than usual, leaving the attacks to stand out. That makes the sound 'punchier', and that allows a strong drive over shorter periods to allow power saving and some way to overcome the losses due to inefficient coupling. There may well be other tricks too, like the shifting of amplitude from the bass fundamental to the next few harmonics.

Alex Coleman wrote in news:Xns97C07204D1EE171F3M4@127.0.0.1:

Good question. Even if you add bose to the terms, then try again after changing to the Google suggestion of nonodrive, I don't see any different. Perhaps it's related to the term 'plug top' which wasn't in the training I was given 20 years ago, but seems to be both current and dating back 40 years. Whatever was wrong with 'plug and socket'? :) WHile we're at it, could these new terms mean that an incandescent lamp will be known as a 'bulb' to differentiate from a 'tube'? And if anyone has any advance warning of impending legislation/convention/regulation to cease calling a spade a spade, I'd welcome the head's up. That is all. >:)

I think it has to do with the frequencies you want to reproduce. To play bass frequencies you need to move more air masses. To play treble frequencies you don't need to move much air. Have you tried to play a techno song with your mp3 mobile? The drums are aweful. But the high frequencies are almost cristal clear. Never ask a good response to bass freqs in a 1/2"x1/2" speaker, I suppose...:-)

I built a "Klipschorn" from drawings one of my fellow engineers at Bell Labs drew up in 1950. With the popularity of stereo, it was hard to find a room with corners in the right place, but it made a wondrous sound! :-)

From my post of 5/6/06 "Speaker impedance":

".... I recall talking to Paul Klipsch, the inventor of the "Klipsch horn". This was a speaker enclosure about six feet tall and four feet wide that sat in the corner of a room and used the corner walls and floor as an extension of the horn. Paul contended that there was no such thing as a "small" low frequency wave."

I've often wondered what he might think of the speakers they're now offering under his name!

Virg Wall, P.E.

No it's about the other parameters of proper design.

A speaker housing and entire device cabinet that doesn't resonant. An amp circuit that can provide the necessary current without severe distortion. A speaker that can likewise handle it.

Many simply thought the size of the speaker was the main criteria when it is simply that small speakers are also more commonly very cheap ones. Someone could make a really low quality larger speaker, put it in a terribly resonant cabinet and drive it will too low a wattage amp and it too would sound terrible... though tend to have more bass.

What you say seems to make a lot of sense to me.

It seems also to be similar to what SRS Labs provides in their audio rendering products.

That link leads to things like these:

Ehnaced spatial rendering and sound impact

Bass enhancement thru harmonics

etc

kony wrote in news: snipped-for-privacy@4ax.com:

No again. >:) He's right. There are two diverging methods now. You're talking about the pure form, the striving for true hi-fi, where basic techniques are refined.

THis thread isn't about that though. It's about how speakers small enough to have no chance of rendering real air moving capability without shaking themselves to brittle fatigued pieces, mounted in tiny sealed baffles that couldn't accept such movements without developing deap-sea pressures even if such air movemnt were possible from those little speakers, can still somehow produce good bass. All kinds of non-purist tricks must be used.

Actually, some of those tricks should be used even by the purists. The mani one being panning and balance set by delay and not only by varing the signal level. Try it with a flanger effect, set the feedback to zero, modulation off, and adjust the sub-millisecond delays slowly to afect an already-panned signal. This simulates the tiny delay our heads cause to incoming sounds (That's what the 'head related transfer functions' thing is about, btw). This, combined with subtle low-pass filtering, can make a signal pan well beyond the speakers.

There are several reasons why such tricks are not used in purist hi-fi:

1. Expense. Until recently, it's been prohibitive.
2. Subjectivity. The delay needed to make a degree of panning depends on ear and head shape.
3. The effect has been used as a gimmick, and has got a bad reputation in a purist context.

If I were designing a balance control for hi-fi based on this I'd have a main balance control that had a couple of smaller controls beside it, one for filter, one for delay. To set it up, pan main hard left, then adjust delay for making the sound go to best extreme for proper location left for whoever is going to listen. Check it again on the right, then use the main, then adjust the filter till it feels right. It's more complex than the usual set of controls, but not much. It's no good setting up digital poresets, a thing like that has to be as hands-on as the controls we've got used to over decades.

Not sure whether the bass enhancement thing counts so well for hi-fi use though. It might in active speakers though, where the aim is to match the power gain stage with the transducer to air coupling. When you have that much control over the output device, it probably can get hi-fi results for a small bookshelf system.

An extra point: If you can try that flanger experiment, set the amplitude on each channel the same. :) What's amazing about this, is the delay part of the panned signal can place the location further left without level difference than the level difference can do without the delay, even when the level is full in one channel and ABSENT in the other!

That should be enough to convince you. But you'll have to do it. Don't just take my word for it.

I'll take your word for it, because I will always be a purist and never wish for any digital REprocessing of the signal.

I built my own headphone/pre/power amps from scratch though, I'm pickier than most.

On a sunny day (Fri, 12 May 2006 05:10:23 -0400) it happened kony wrote in :

What system, i am curious, electrostatic, dynamic, dynamic wit ha coild in teh membrane? Or piezzo? I once build a smal ldynamic one.... when you find you need permanent magnet bias... Also did some experimenting with piezzo.

Is yours betetr what you can buy commercially? (mine was not).

/pre/power amps from scratch though,

Yes done that too.

Na I am not, listening on PC speakers to my music now:-)

Dis someone mention horn? "Dig" these (scroll down)

Regards,

Boris Mohar

Got Knock? - see: Viatrack Printed Circuit Designs (among other things)

void _-void-_ in the obvious place

That's really carrying things to an extreme! The one I built did use two four by eight foot sheets of 3/4 inch plywood, but no concrete! :-)

I noticed the power amp uses transformers. At one time the "hi-fi purests" claimed iron core devices distorted the waveforms. Transformer less designs were all the rage, neglecting the fact that the signal had probably been through many transformers before it reached the final listener.

Virg Wall, P.E.

My MSI motherboard has a Realtec AC97 six channel sound system. There is a built in demo which uses delay plus volume to "move" a sound source. Now that everything has gone digital it's much easier to implement this sort of thing. I can recall experimenting with screen door springs with phono pick-ups attached, to simulate audio delay.

Made some interesting sounds, but hardly hi-fi!

Virg Wall, P.E.

membrane?

bias...

no i meant headamp. I usually listen to Sennheisers or Grados.

On a sunny day (Fri, 12 May 2006 15:07:55 -0400) it happened kony wrote in :

membrane?

bias...

OK, I had a Senheiser too. Was very good.

VWWall wrote in news:7b39g.1573$ snipped-for-privacy@newsread2.news.pas.earthlink.net:

Nor is 2-channel stereo. But it's a convention we've come to accept.

Actually, many sounds are processed with delay panning to set a realistic position. WHile it's possible to overdo it, rendering the effect weird for all but the largest ears and heads, there's nothing wrong with doing it in moderation, it just means that those with largest ears and heads will hear it slightly narrower field than most.

The one thing that gets to me about the purist thing is that I've seen people worry about silver speaker cables, or the tiniest differences in an MP3 encoding process, and various other things, when the differences in the musicl process, or the final mix, or even a bit of EQ on the stereo mix, all make far more bold changes to the sound. If it sounds good, people will accept is hi-fi, so long as they don't see that crude assembly of signals at their end.

If you want a great take on that whole thing, listen to a song by Micheal Flanders and Donald Swann. >:) It's called 'A Song Of Reproduction'. It encourages a healthy wariness of too much narrow refinement. The reason why such things as big sounds out of tiny speakers are amazing people right now is that it's taken the computer industry to shift people's perceptions far enough and fast enough to make it possible to try things which have actually been commercially and technically possible for decades. It's the limited concept of what is 'hi-fi' that has had to break down first.

People can agrue till death about how hi-fi is simple, only to reproduce the original sound, but it can't. No two-channel system can. Which is the point, The only way out of a circular argument is to accept new ideas into 'hi-fi'.

The answer is easy, the goal is not "bold changes", it's accurate reproduction. Some will psychologically err when they assume their further tweaking of audio cables sounds better without an ABX test but even that isn't valid- because multiple changes below a threshold of discrimination (taken alone) can sum to a perceivable difference.

Audio is so subjective though, it's fairly impossible to generalize that "people will accept is hi-fi" when talking about all the possible variations. Even a crude $3 AM radio sounds pretty good compared to silence but set it next to something better... so ignorance can be bliss, the road to perfect sound is long and winding.

Those who do the most critical listening seem to disagree and prefer 2 good channels over digitally mutilated sound. There's nothing wrong with digital at all, to preserve, not change the sound.