OT: Selecting the Right Speakers

[phillip]

I'm considering buying a 100W head so I would also have to construct a speaker cab for it, and I think a 2x12 will be just right.

How do I know which speakers will safely work with a 100W head?  I have the ability to buy speakers from Fender at dealer cost, and they have a fairly wide variety of 12" speakers:

-12", 8 ohm, 30W Alnico
-12", 8 ohm, 50W Ceramic
-12", 8 ohm, 60W Celestion V30
-12", 8 ohm, 75W
-12", 8 ohm, 80W Celestion G12-80
-12", 8 ohm, 80W
-12", 4 ohm, 100W
-12", 8 ohm, 100W

Does each speaker have to be able to handle 100W, or does it work in series, i.e. two 50W speakers in series (if they're wired in series) would be able to handle 100W?

TIA!
Phillip

[B9 Robot]

Phillip,

Two 50W speakers would work or four 25W speakers,etc. Since a 100w amp can put out more than 100w when overdriven, it has been suggested to multiply your amps power by 1.5 and select speakers that will cover that amount of power, to be safe. If you plan on using a combination of different speakers (I would recommend this because many times two different speakers compliment each other well) use the one with the smallest wattage rating and multiply that by the number of speakers you are using to figure your power handling. For example, if you had a 100w and a 15W speaker in a 2X12, it would only be safe to run 30W through it, not 115W or an average of the two 57.5W.  I hope this helps.

Todd

[petemoore]

Unless two types of speakers use the same voice coil, or are measured for ohmage...
 Rephrase: the times I've read ohmage and used different types of speakers wired in P or Series, even if they are rated for say 8ohms, there has been an ohmage and loading difference, one would be louder than the other. Unless I was able to test or knew what I was doing, I stick with the same type in one homeloaded cabinet.
 They are probably Herald Speakers? Those are good, as are the Jensens.
 Jensen site might be a good thing to look up, somewhere around here I saw a listings page with brief descriptions of what the different ones do.
 I opted for Greenbacks, tho would gladly use Blueback or equivalent Jensen 25-30W drivers. I like the tone of lighter cone structures, or what was used in the original old Fenders and Marshalls.
 I have best knowledge of Jensens and Celestions, tho I had Heralds in a HR Deluxe [2x12], they sounded great on clean...I don't know what they'd do with a gainier amp for Dist.    
  I've found that I love the way a 50w amp drives 4x12's. 100w is so fun outdoors, or if you get a schedule involving larger venues. I don't think you'd even be able to really break the 100 over with four nice 12's.
 Often misconcepted is the Wattage vs level. Higher wattege speakers don't really get alot louder with tone, 4 x 25w speakers in a 412 enclosure get fiercely loud, but have a breakup that is ''very pleasing[given the amp is responding 'right''].
 If I could find a bar that likes a loaded 100w, It'd be worth having one, just for fun though, one of those with the right effects and a place to blast off, provides amazing amount of excitement, as well as a being great tutor.

[phat-ass]

Check this link out about making speakers:

http://www.duncanamps.com/technical/speaker_cab.html

It's really good.

This is a really good Excel Spreadsheet:

http://www.duncanamps.com/technical/impedance.html

It's for figuring impedences of speaker cabinets.

Also you should go to:

//www.Eminence-Speaker.com

They have quite a bit of stuff there.

Are you going to be building an open back or sealed cabinet?

The differences are pretty important. If you are building an open back speaker you don't have to know that much, just build a box. Sealed cabinet is way more involved. That first link I posted explains that in detail.

phat

[phillip]

It'll be an open back cabinet for ease of design and construction.

Are there any good construction plans for a 2x12 open back cab floating around on the internet?

Phillip

[phat-ass]

No plans per se. Just read that article from Duncan amps. There's a particular point about just building a 2x12 cabinet in that article.

phat

[Arno van der Heijden]

This site is also handy:

http://colomar.com/Shavano/copy_cabinets.html