The significance of magnet speakers

[GibsonSGgirl]

My 68 Deluxe Reverb came with a non-orignal magnet speaker. While I think it sounds fine with it, I'm curious as to know what some of the differences are between magnet speakers and regular, ie, stock, speakers are.

What's the significance? Why would someone prefer a magnet speaker to a stock one? Or can the magnet be removed? What's the magnet used for?

Sorry, lots of questions, but I'm a newbie when it comes to learning how stuff works...

[Boogs]

Not sure what you mean by "magnet speaker"... Speakers have traditionally either come with a ceramic magnet or an alnico magnet, and now they can have a neodymium magnet sometimes.

Perhaps your amp came with a speaker that didn't have the original magnet in it?

[GibsonSGgirl]

Well, mine looks like a normal speaker it just has a huge square magnet stuck on the back of it. See pics.

[bluesdoc]

Speakers are a HUGE part of the final tone an amp/cab produces and it can be a long process of trial and error finding a speaker that suits one's amp/guitar/drive stuff/style, etc. I wouldn't get overly concerned about which type of magnet is employed for any given speaker in an amp/combo/cab but rather what sort of sound is created by that speaker. With all the choices out there, getting advice from experienced gear heads can really helpful. But even then, there can be lots of trial and error. I'm in my 5th decade of playing, and I'm still trying and erroring.... . And what sounds good at home might not be so ideal at a gig. The room becomes part of the cab's resonant acoustics ....... It's close to endless, but not an impossible task. And it's WAYYYY cheaper than swapping amps... - especially with the selections available these days (eg, Eminence selections, etc)

And Boogs, how about the early 50s and before EM speaker mags!! No PM at all! Four wires to the speaker - two to power the mag and two for signal. I clearly remember taking apart my folk's Stromberg-Carlson 'hi-fi' around 1951

jon

[GibsonSGgirl]

Thanks Jon for the info! What I'm wondering is, what would happen if I decided to take the magnet off? Would I seriously mess something up? Why does my speaker have it and all the original speakers from the period I see not have one, or at least not a big visible one like on mine?

[Distortion788]

Originally Posted by GibsonSGgirl

Thanks Jon for the info! What I'm wondering is, what would happen if I decided to take the magnet off? Would I seriously mess something up? Why does my speaker have it and all the original speakers from the period I see not have one, or at least not a big visible one like on mine?

The size of the magnet (in most circumstances other than specialty materials like neodymium) has a direct correlation with power handling. The bigger the magnet, the more power handling the speaker has, typically. Different materials that are used (ceramic, alnico, etc.) will also affect the size of the magnet and power handling.

A speaker will not function without a magnet.

In more detail...

"The speaker magnet is there to provide a permanent magnetic
field for the the speaker coil, which is connected to what is called a 'pole piece'
under the speaker cone. When the audio signal flows through the speaker coil it
generates a small magnetic field the strength of which varies with the
strength of the audio signal. This small magnetic field is repelled
by or attracted to the permanent magnetic field produced by the
speaker magnet. Thus the paper cone moves away from or closer towards
the back of the speaker. Hence as the strength of the audio signal
wiggles the paper cone wiggles back and forth, and you get sound waves
that match the audio signal..."

[GibsonSGgirl]

Wow that's a cool description. I love learning things like that!

[Scooterjohn]

Originally Posted by Distortion788

"The speaker magnet is there to provide a permanent magnetic
field for the the speaker coil, which is connected to what is called a 'pole piece'
under the speaker cone. When the audio signal flows through the speaker coil it
generates a small magnetic field the strength of which varies with the
strength of the audio signal. This small magnetic field is repelled
by or attracted to the permanent magnetic field produced by the
speaker magnet. Thus the paper cone moves away from or closer towards
the back of the speaker. Hence as the strength of the audio signal
wiggles the paper cone wiggles back and forth, and you get sound waves
that match the audio signal..."

Very cool...you managed to use both "thus" and "hence" in the one description.

[aeolian]

Originally Posted by Scooterjohn

Very cool...you managed to use both "thus" and "hence" in the one description.

And imply that the pole piece was connected to the voice coil instead of the magnet structure.

[devbro]

Generally speaking, speakers with larger magnets will have more headroom and breakup later. As the voice coil moves forward, the magnet pulls it back (or vice versa). The quicker the magnet pulls it back, the faster it can complete a push/pull cycle which creates a "tighter sound". This is why JBL's, EV12L's, etc, with giant magnets are so clean sounding and have such enormous headroom.

[Chris Rice]

Some fantastic speaker info here:
http://www.tedweber.com/reference.htm

It'll keep you learning for hours.

[r9player]

btw looks like yuor speakers are old speakers with replacement mangnets ... they look kinda big even (bigger then a Jensen's would)

[908SSP]

Lots of replacement speakers back in the early 70s had those square magnets. They were never warmly received and fell out of common usage. If they sound fine to you leave them. If you would like speakers closer to stock check and ask around I am sure people can suggest some that would do the trick.

[OOG]

they look like CTS's to me
typical for the period and not the greatest sound imho, kinda edgy
put an Eminence C Rex in there

[aeolian]

That looks really similar to the Cerwin Vega speaker that came in my Polytone back in the 70's. I bought a spare and had it in another cab. Pretty decent sounding speaker. Capable of handling much more power than needed for a Deluxe Reverb.

Originally those amps came with speakers from CTS or Utah. I think some Eminence were also used a bit later on. Some folks who are really into this could probably say exactly if you want to go on a search for replacing the original.

But there are many speakers out there today that are great. And you can tailor the sound of the amp with whatever speaker you put in there. Do a search on Deluxe Reverb speaker or DR speaker. There have been many threads on this. The best sounding Deluxe I've ever heard had a Webber Silver Bell with an alnico magnet in it. But I didn't crank that amp to gig volume. At somewhat less cost, I have an Eminence Red Fang in mine to get a similar chimey sparkly sound. But that speaker doesn't sound good to me at gig volumes. Alnico magnet speakers compress the sound as you get louder. Some people like this effect. I don't. My taste is for a lot of dynamics in the sound. I have in boxes in the basement a Celestion G12-H30 and an Eminence Tonespotter that I can put in there if I want to use that amp to gig with. I've tried both in there and would probably use the Celestion. Robben Ford has a fabulous sounding Deluxe Reverb that has a Celestion 65 in there. If you look though the DR speaker threads, you'll find all kinds of recommendations and descriptions of the colors those speakers add to the sound of the amp.

Welcome to the world of GAS.