Ceramic & Alnico of different sizes in the same cab?

[blaineadd9]

A while ago I played a rig at a guitar store that consisted of an '85 bassman with a homemade cab. The cab had 1 12" speaker and 1 10" speaker, and one of those two was ceramic. I want to recreate this with a 63' bassman head I just acquired.

 

I just ordered a Mather cab to accommodate the two speaker sizes and now I'm looking into which speakers would be most musical. Sadly, this is my first foray into the non-stock world and I am totally lost. Any advice or suggestions would be appreciated!

 

Thanks!

 

Blaine

[Mr.Grumpy]

This is for guitar use, right?

 

First concern needs to be matching the impedance (ohms) between your amp and the speaker cab. Assuming you want an 8 ohm cabinet, you'll want either two 16 ohm speakers if wired in parallel, or two 4 ohm speakers if they're wired in series... But if you need either a 4 ohm or 16 ohm cabinet, then you just need two 8 ohm speakers. Are you confused yet?

 

Once that's sorted out, there's still a lot of choices to be made, and I'm afraid I won't be much help. People will ask you what kind of music you play, and what sort of "tone" you're looking for. I do know Eminence and Celestion are considered "good" brands, Jensen is still around (they made Fender OEM speakers back in the day), and I hear Weber makes good speakers. JBL and EV (Electro-voice) are well respected if pricey brands too.

 

Some of the guys in the amp forum seem to know a lot about speakers, but it's one of the rougher neighborhoods in HarmonyCentral Land.

[WRGKMC]

A couple things. For proper functionality First is impediance. Older fender bassman amps ran on 4 ohms. Two 8 ohm speakers wired in parallel will give you 8 ohms. They will run on 8 ohms and shouldnt cause a problem with new tubes. To get that, you would need two 16 ohm speakers wired in parallel or two 8 ohm wired in series.

 

Ceramic speakers have a hard breakup and an alnico have a softer smoother breakup. How they sound together is purely try it till you find a good combo. Alnicos are more expensive and much lower wattage than ceramics so you need to be careful not to blow the alnicos with overwattage.

 

Next is tone and balance. To match the outputs you need to match wattage AND SPL level. If one speaker is very loud and the other is weak, the weaker wont do much for a fuller tone.

 

Lastly you have the frequency responce of the two speakers. If both have a big hump at one band of frequencies, you may have certain notes player that are loud and others that are weak. The cab also comes into play here. Sealed Cabs have a certain air volumes that are designed to match the resonant frequency of the speaker. Most guitar speakers fall within the same responce range so the bass frequencies shouldnt be off too much with a miss match, but there can be a issues with PA and Bass cabs where the cam needs to have the proper air volume to reproduce low frequencies properly. Guitars are midrance instruments so the bass gets rolled off most of the time anyway.

 

 

So if you go here, and look at the specs on this alnico speaker. http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-473

 

Its 35 watts which is about as high as you're going to get on a 10". Sensitivity/SPL(loudness) level is 97.5db which is really good, then the frequency responce id 100~5.5K which matches guitars very well. Guitar range is usuall about 140~5K or so so you wont loose any frequencies.

 

To fin a ceramic match I found this one http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-480

 

The SPL is 98.8db, just a littel louder than the 10". The frequency responce is 80~4200hz, so the speaker will be a littel deeper than the 10". Wattage is 150w so there no problem there. If anything you wont get any speaker breakup like you might with the 10".

 

The balance of the two should be pretty good. The 10" may be a littel lower but it will put out more on the top end. The 12" will hold a solid low end and supply the working power for guitar chords. The 10" should break up a littel playing leads which are usually higher on the neck so this combo may work well together.

 

For a better and louder match I may use these.

 

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-840

 

http://www.parts-express.com/pe/showdetl.cfm?Partnumber=290-808

 

The SPL levels match and the frequency responce does too. The wattage of both is high enough to where I'm not worried about blowing the alnico, and its a combo of british and american sound so it would be versitle for getting both a marshall/fender sound.

 

For an old fender though I'd likely go with these.

 

http://jensentone.com/p12q.php

 

and

 

http://jensentone.com/p10q.php

 

Jensons, Utah, Oxford, and Altec and Rola speakers were used in many older fender amps You also found Electrovoice CTS and Eminance in others. The ones I first listed were eminance which are pretty good. I went with Jensons in a 4X10" cab with my 66 Bassman to get the classic blonde sound which I really like. The SPL level was a bit lower than the Eminance but I really like the cutting midrange they put out and how they break up at high volume. I like how they sit with my voice singing too. nothing worse than having too much top end. You rag your voice out trying to sing above the guitar frequencies.