Talk:Loudspeaker/Archive 2

Loudspeaker manufacturers

We need a separate article for this. Comments?--Light current 22:02, 20 May 2006 (UTC)

The list should be deleted. If it was a separate article, for example List of loudspeaker manufacturers, there is a good chance the list would not survive an AFD. Manufacturers should only be mentioned on this page if they are notable. AlistairMcMillan 22:14, 20 May 2006 (UTC)

Yes. Let the list stand or fall by its own merits!--Light current 22:32, 20 May 2006 (UTC)

Floorstanding pic?

An image of a tower speaker would be a nice addition if anybody has one. Also, could some of the talk be archived? It's awful long.

Archiving: Done. Folks should, of course, feel free to copy-back any archived discussion they feel wasn't finished.

Atlant 15:39, 8 June 2006 (UTC)

Well that was quick. I'd've left some of 2006. I guess we'll see if anybody is bothered by it. --Howdybob 23:04, 8 June 2006 (UTC)

You can always bring some back if you think its been prematurely archived. 8-| --Light current 23:36, 8 June 2006 (UTC)

Added floor-standing speaker photo. Rohitbd 15:27, 28 June 2006 (UTC)

Last three sections are unnecessary or covered elsewhere

I removed these and added links to home theater and surround sound in teh szee also section.

Home cinema speakers

There are various different speaker set-ups for home cinema speaker systems. They include :

• 5.1 channel sound. This requires:
  • Left, center, and right front speakers
  • Left and right surround speakers
  • A subwoofer (which is counted as ".1" channel because of the narrow frequency band that it reproduces). This speaker can reproduce the bass frequency from all the main channels or may only do so for those speakers incapable of doing so. This is usually achieved by an amplifier setting of 'large' or 'small' defining the speaker type.
• 6.1 channel sound is similar to 5.1 but there is an added center rear channel
• 7.1 channel sound in home theater is identical to 6.1 except that it has left and right rear speakers. In SDDS, 7.1 is the same as 5.1 but adding center-left and center-right speakers in the front of the listener for better audio positioning.

It is important to note that the sound channels offered to the speakers may be original individual channels (normal 5.1) or they may decode additional channels from the surround channels (This distribution can be accomplished by a Dolby Digital EX decoder, a THX Surround EX decoder) or they may be simulated (where the two surround channels are spread to center rear or twin rear speakers.

See also: Home theater in a box

Wireless

So-called wireless loudspeakers are becoming popular in many applications, such as home theater, due to their convenience, removing the need to run speaker wire. Despite its name, however, the unit is really a wireless receiver, amplifier and loudspeaker in a single box.

Multi driver systems

Home cinema systems generally include multi-driver systems.

'Multi driver' refers to any speaker system that contains two or more separate drive units, including woofers, midranges, tweeters, and sometimes horns or supertweeters. Many multi driver systems use a bass reflex, or ported, design. These incorporate a small hole, (called a port), in the speaker cabinet to allow the low frequencies generated by the rear of the woofer cone to escape from the cabinet in phase with that radiated from the front of the cone. This improves the bass response of the system.

The multidriver speaker stuff doesn't appear anywhere else in the article or in Wikipedia, so I put it back in, tried to integrate it better. Gzuckier 18:20, 13 June 2006 (UTC)

Doesn't the inconsistent hyphenation look a bit untidy to everyone else? Not knowing which one to keep, I won't change it myself. Carl Turner 15:54, 26 September 2006 (UTC)

Loudspeaker shape?

Why is a Loudspeaker always round and cone shaped the way is invariably is? I havn't seen or heard this discussed amywhere. I assume it's beacuse of the shape of a sound wave, but I would love to hear a detailed explination, and of any variations on it.

It's a question of the physics of coupling energy from the voice coil to the part of the speaker that pushes the air. The voice coil represents (more or less) a point source of mechanical force. The thing that moves the air must occupy an area larger than a point so that it can create a substantial (audible) change in pressure and it must be stiff enough not to distort (much) under the force applied by the voice coil and resisted by the air. The end result is that a cone is the easiest shape to engineer that meets these various criteria.

Flat speakers (with styrofoam moving elements) have been made, but they don't perform as well as conventional conical speakers.

Ribbon tweeters are another example of a non-conical speaker. In that case, the entire ribbon is simultaneously the voice coil and the driven part that pushes the air.

Atlant 11:23, 2 July 2006 (UTC)

In the late 80's and early 90's there were some square speakers, which sounded quite well. I have no idea why those don't exist any more. I have seen some Sony and Aiwa models.--Lenilucho 16:05, 2 July 2006 (UTC)

AFAIK, the problem with shapes other than round is directivity - a round shape will exhibit the same directivity in both the vertical & horizontal planes (or axes), but an oval shape will have greater directivity along the elongated axis. A rectangular shape will have increased directivity along the diagonals (and the longer side). Also, manufacturing circular cones may be easier than other shapes. Rohitbd 13:33, 10 July 2006 (UTC)

About Tesla

On the question of Tesla's possible invention, see: http://www.tfcbooks.com/teslafaq/q&a_040.htm

In particular this quote attributed to Tesla (1916): "Whenever I received the effects of a transmitter, one of the most convenient and simplest ways [to detect them] was to apply a magnetic field to currents generated in a conductor, and when I did so, the low frequency gave audible notes." Page author cites Prodigal Genius by John J. O'Neill. It sounds like Tesla was listening to the raw note produced by the wire (the wire would vibrate in the field) rather than to a coil attached to a cone. Busy man. Twang 00:34, 11 July 2006 (UTC)

Efficiency section cleaned up somewhat - needs more work

I snipped the following text from the efficiency section of teh main article. I susggest it gets its own home in an article or section on dB Drag contests, although some of the text in question is factually questionable or misleading, IMO.--Ron E 16:28, 28 October 2006 (UTC)

Current state-of-the-art loudspeakers can approach apparent efficiencies of 70% or higher, but only under very special circumstances and in a narrow frequency range around resonance. In closed or small environments (such as cars or bedrooms) it is far more important to have a speaker with a high X_max (cone eXcursion maximum) as opposed to high (dB/(W·m)) rating. A higher X_max indicates that the driver can move a larger volume of air as power increases. A few top of the line woofers have a very low "sensitivity" rating i.e. 80 to 86 dB/(W·m) (a nominal efficiency of 0.1%). However at full power in an enclosed automobile may achieve 160+ decibels at 20% to 40% apparent efficiency. In general a low frequency speaker designed for high SPL's will have a larger and or heavier magnet, and a higher X_max.

• video of 158 dB woofer at 80 millimeter amplitude 450 kB mpeg As shown in this example, sometimes the speaker with the lower sensitivity rating has a far higher amount of acoustic output.

Present and future

Loudspeaker enclosures are likely to advance as far as they did in the late 1950s, thanks to new materials that can allow manufacturers to produce the required heavy walls with curved shapes. Defeating the 10% distortion levels of straight-sided enclosures is now cost-effective for mass manufacturing, and sound quality improvements will be available with products for the common consumer with the common budget. Products using curved shapes and heavy walls will become available with sound quality improvements immediately noticeable to the average consumer. Enclosures may even become works of art. Professional public sound at concerts may use fully spherical or egg-shaped loudspeaker enclosures.

The text above appears biased and factually incorrect. Straight sided enclosures do not have "10% distortion". Egg shaped and spherical enclosures have been possible for many years.--Ron E 16:43, 28 October 2006 (UTC)

See Also section

The RMS link in the See Also section links to a disambiguation page. someone needs to fix it, so please post back here when you have done it.

Thanks

Stwalkerster 14:07, 13 September 2006 (UTC)

And why didn't you want to be bold and fix it?

Atlant 14:22, 13 September 2006 (UTC)

Yeah do it yourself! 8-)--Light current 01:25, 27 November 2006 (UTC)

Out of phase Head Phones

I need some help. I have two pairs of Coby CV-H56CIR headphones both which have an out of phase connection making one speaker louder than the other. How can I fix them without modifying anything? 68.168.82.226 02:30, 26 November 2006 (UTC)

I'm a little confused about your diagnosis. Do your headphones have several drivers per ear? Otherwise, an "out of phase" condition (with the left ear phase reversed from the right ear) wouldn't lead to a difference in apparent loudness; instead, it leads to bizarre stereo imaging.

In any case, some headphones have four-wire cords so that you can set the phase of the drivers by reversing a pair of leads at the stereo phone plug. Otherwise, if you're really sure you have an out-of-phase condition, you'll be taking the headphones apart and rewiring them.

Atlant 22:41, 26 November 2006 (UTC)

Conversely, you could swap your ears around! 8-)--Light current 01:23, 27 November 2006 (UTC)

RMS power

There is no such thing as RMS power. I correct. --82.158.89.187 14:15, 8 December 2006 (UTC)

Sensitivity

Sensitivity should not be expressed as dB/W·m because that would imply that there is an inverse and linear relationship between the SPL and the power or distance. This is not true. It shoud not be expressed, either, as dB/W/m. The correct term is dB for 1 W at(or @) 1 m. Sorry for my english.--82.158.89.187 15:29, 8 December 2006 (UTC)

Sub, Midrange, and Tweeter

The portion of the article that refers to the different speakers (sub, mid, and tweeter) is incorrect. Vritually no "subwoofers" go above 200 hz. High drivers generally kick in at around 12k ish. This portion of the article needs to be rewritten for accuracy. Austinro 17:55, 27 December 2006 (UTC)

I'll buy your claim about the subwoofer crossover frequency but you're clearly wrong about the 12KHz tweeter crossover frequency. Try the following Google search and see what you find:

• http://www.google.com/search?hl=en&lr=&q=dome-tweeter+woofer+midrange+KHz+crossover-frequency

3 to 4 KHz looks much more typical for the tweeter crossover frequency in a typical 3-way (W,M, & T) setup.

Atlant 18:09, 27 December 2006 (UTC)