1966 Jensen C12NSL Bass Speaker(?) Home Brew Question

[bobh1959]

Scored this cab (above) which contained this speaker (below)

The cab is a gutted Lowrey/Gibson T-2 organ amp. The speaker is a 1966 Jensen C12NSL. I've seen many Jensens but never one with an SL after the power rating (N).
I played guitar through it and am pretty sure the SL has something to do with this speaker being much more of a bass speaker than a guitar speaker, heavy bottom and no highs. Does anyone know anything about this variation of the C12N?

I also have a guitar speaker question, please allow me this slight breach of not staying in a proper "Bass" lane. What would be wrong with adding to my cab a vintage 8" CTS speaker suitable for instruments, crossed over at some hopefully optimal frequency to prevent a "mid" spike and to protect the 8" speaker by removing lower frequencies? I'm thinking of using a high frequency roll-off pot to balance any potential sensitivity variations between the speakers. This is essentially a common practice with bass cabs. I know using a horn in a guitar cab is a non starter, but when people say 2-way cabs are poor guitar speakers is that because they assume you'd be using a horn. Essentially my question is what's wrong with a 2-way guitar cab if both drivers are proper guitar speakers?

 

[beans-on-toast]

I have a standard C12N in a Leslie 125 cabinet. That standard model worked fine for low end at the time. The Lowrey speakers had the SL tacked on. Not sure if it was a modified OEM designation or just their part number.

A crossover in a guitar amp has been done in the past. Same for full range studio monitors. so it s't just bass cabs that have them. Always good to include a rheostat or off switch in your design. Sometimes the mid driver is chambered within the cabinet. This complicates things.

 

[bobh1959]

I have a standard C12N in a Leslie 125 cabinet. That standard model worked fine for low end at the time. The Lowrey speakers had the SL tacked on. Not sure if it was a modified OEM designation or just their part number.

A crossover in a guitar amp has been done in the past. Same for full range studio monitors. so it s't just bass cabs that have them. Always good to include a rheostat or off switch in your design. Sometimes the mid driver is chambered within the cabinet. This complicates things.

Good to know about the code, thanks. The mid driver is actually going to be a period correct Jensen C8R. I'm using an 800hz 2-way Eminence crossover and for now I'm not going to chamber the C8R because I'm retrofitting a Premier 120 chassis which is only like 15 watts and the cab is vented in several places. I appreciate your input.

 

[BogeyBass]

if the 8" is crossed over it wont require such a large chamber, since it wont be dealing with bass frequencies.

then again without isolation from the LF or low frequency driver, i wouldn't expect good performance.
others have used sealed back 8" or sealed back 6" speakers to eliminate the need for chamber.

but high crossover points is recommened such as the 800hz you already choosen. but simple 1st order crossovers usually aint enough a 2nd order or 3rd order work better for the sealed backs. when you look at the rather odd impedance curve they have. usually a friendly point of that curve is a reasonably crossover point and frequency. its just good to be aware of the curve since they have a odd jump to them when designing the crossover

with the jenson far as i understand the L was a low frequency driver. most likely yes lower Fs or resonant frequency and will have less highend.
somewhat similar to what celestion did with the G12 with 75hz and 55hz models

 

[bobh1959]

if the 8" is crossed over it wont require such a large chamber, since it wont be dealing with bass frequencies.

then again without isolation from the LF or low frequency driver, i wouldn't expect good performance.
others have used sealed back 8" or sealed back 6" speakers to eliminate the need for chamber.

but high crossover points is recommened such as the 800hz you already choosen. but simple 1st order crossovers usually aint enough a 2nd order or 3rd order work better for the sealed backs. when you look at the rather odd impedance curve they have. usually a friendly point of that curve is a reasonably crossover point and frequency. its just good to be aware of the curve since they have a odd jump to them when designing the crossover

with the jenson far as i understand the L was a low frequency driver. most likely yes lower Fs or resonant frequency and will have less highend.
somewhat similar to what celestion did with the G12 with 75hz and 55hz models

Wow, more good stuff, thanks. I'll follow your advice and isolate the C8R inside the box. Here's the crossover I got for it.
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