Interesting article about guitar speaker design

Jeremiah

http://www.soundonsound.com/sos/feb12/articles/speakers.htm

Includes a discussion with the director of development at Celestion. What I found really interesting is that it suggests that speaker distortion/breakup is not just something that happens only at high volume when the speaker cone is close to its limit, but forms an important part of its characteristic tone even at low levels.

Cirrus

I guess it's a gross oversimplification (and I'll get to reading the article in a minute), but I think of it like this; the middle of a speaker cone moves. The edge doesn't. So somewhere between the middle and the edge, something's going on!

I think that's the main component in speaker break in actually - when the surround is very stiff, the vibration kicked off in the middle of the speaker travels outward through the cone at whatever the speed of sound is in that material. When it gets to the edge which can't move, it's got nowhere to go but reflect back into the cone. The result is lots of nasty cancellations/ interactions/ standing waves. Once the speaker's broken in more the surround is softer so the majority of the cone's movement is closer to that of a piston and not as much sound wave reflects back off the edges of the speaker.

Dave_Mc

Jeremiah said:

What I found really interesting is that it suggests that speaker distortion/breakup is not just something that happens only at high volume when the speaker cone is close to its limit, but forms an important part of its characteristic tone even at low levels.

I've been saying this for a good while. All you have to do is try a bunch of different speakers next to each other, and even at low volumes, some will sound dirtier/grittier than others.

ICBM

Cirrus said:

I guess it's a gross oversimplification (and I'll get to reading the article in a minute), but I think of it like this; the middle of a speaker cone moves. The edge doesn't. So somewhere between the middle and the edge, something's going on!

I think that's the main component in speaker break in actually - when the surround is very stiff, the vibration kicked off in the middle of the speaker travels outward through the cone at whatever the speed of sound is in that material. When it gets to the edge which can't move, it's got nowhere to go but reflect back into the cone. The result is lots of nasty cancellations/ interactions/ standing waves. Once the speaker's broken in more the surround is softer so the majority of the cone's movement is closer to that of a piston and not as much sound wave reflects back off the edges of the speaker.

Yes it is an oversimplification, but like a lot of these things it's very useful.

Dave_Mc said:

Jeremiah said:

What I found really interesting is that it suggests that speaker distortion/breakup is not just something that happens only at high volume when the speaker cone is close to its limit, but forms an important part of its characteristic tone even at low levels.

I've been saying this for a good while. All you have to do is try a bunch of different speakers next to each other, and even at low volumes, some will sound dirtier/grittier than others.

If it wasn't true, speakers would all sound the same at low volume, and they don't at all.

It also disposes of the myth that you need to "push" speakers to get "breakup" or make them sound good. You don't - with a few exceptions, all of which I can think of that have fairly stiff edge surrounds and need a little bit more power to make them move freely... the V30 being a good example.

If anything, pushing the speakers too hard so the breakup becomes chaotic doesn't actually sound good - or at best, sounds like Neil Young. (Which I am well aware is the same thing to a lot of people .)

thermionic

Excellent article.

Dave_Mc

ICBM said:

Dave_Mc said:

I've been saying this for a good while. All you have to do is try a bunch of different speakers next to each other, and even at low volumes, some will sound dirtier/grittier than others.

If it wasn't true, speakers would all sound the same at low volume, and they don't at all.

It also disposes of the myth that you need to "push" speakers to get "breakup" or make them sound good. You don't - with a few exceptions, all of which I can think of that have fairly stiff edge surrounds and need a little bit more power to make them move freely... the V30 being a good example.

If anything, pushing the speakers too hard so the breakup becomes chaotic doesn't actually sound good - or at best, sounds like Neil Young. (Which I am well aware is the same thing to a lot of people .)

LOL

And agreed.

I don't even mind the V30 at low volumes, at least for certain things. That's true ("certain things") for most , if not all, speakers, though. But it may also be true that they don't sound quite as good as some other speakers at really low volumes.

ecc83

A guitar speaker has a magnet, basket, voice coil and cone just the same as a "hi fi" woofer but there the similarity ends.

Even my dinky Tannoy 5A cones have a pk-pk displacement of around 8mm. A Super 65 (G12N-65) I happen to have handy has barely half that and is far stiffer. Bottom line: Guitar speakers do not work as "pistons" to hardly any degree at all and are really just a vibrating membrane.

That you don't need to drive the bllx off a speaker for good sound was brought home to me when Son and I were playing around with a 15W Dominator clone and he got the best ZZ Top "grind" at a measured 90dBC SPL at a mtr from a Greenback. That is well under a watt!

Dave.