Celestion Spider Frame G15C (15" 50w 16ohm) T/S specs?

[VTypeV4]

I have a vintage G15C that was bought from eBay for next to nothing although after a few weeks use it developed a slight coil rub. I have since removed the magnet and re-aligned it and now the speaker works great without complaint.

Does anyone have the T/S specs for this unit? My plan is to put a custom built enclosure around the unit and plan to go down the vented box route to extend the low frequency response a touch. I expect originally it would have been put in a smaller than ideal sealed enclosure.

It'd be great if anyone could help.

I have also emailed Celestion and am awaiting a response from them.

Many thanks, Matt

[IMG]http://i778.photobucket.com/albums/yy70/VTypeV4/Cel1.jpg[/IMG]

For easy reference, this is the drive unit in question..

[Mr. Foxen]

Gut feeling is a vented enclosure isn't going to suit that at all. Really massive sealed box for any low, and even then not much, or small sealed box and use it for nice mids with some speaker breakup.

[VTypeV4]

Thanks Mr F and not meaning to contradict but..

I got this from Dr Decibel at Celestion..

[i]Hi Matthew[/i]
[i] Sorry we don’t have parameters for these things. Try downloading Audua’s Loudspeaker Workshop which will teach you to measure the parameters of your speaker. You will likely end up with a box between 75 and 100 litres tuned to around 45Hz using two 100mm diameter vents 300mm long. That’s a good practical size for a 15”. Remember its getting old now so be a bit sympathetic if you hear it struggling!![/i]

[i]Regards[/i]
[i]Doc[/i]


My plan with the vented box is to give an extended low end a little but also give the unit a slightly easier life within it's operating parameters. I don't plan to gig the box particularly or even work it hard, it'll probably be used for recording too being driven by a 60w valve amp at little above bedroom level..

It was on my understanding that a vented box was easier on a drive unit of any description when operated above Fb?

[Mr. Foxen]

If you use a high pass filter its safer. But simultaneously saying they don't know the properties of the speaker and also making recommendation as to what to do with it doesn't fill me with confidence.

[VTypeV4]

[quote name='Mr. Foxen' timestamp='1360718463' post='1975505']
If you use a high pass filter its safer. But simultaneously saying they don't know the properties of the speaker and also making recommendation as to what to do with it doesn't fill me with confidence.
[/quote]

Thats a fair point, I hadn't considered that..

It sounded OK in my WEM cab so maybe something of that description is in order but just a little larger voulme wise? I was thinking somewhere between the size of a Trace Elliot 1153 and a 1518..

I guess without data other than Fs (55Hz), and a guestimated Xmax of around 3mm it's gonna be a case of build it and see?

[Mr. Foxen]

Other option is build an enclosure suited to another available driver with known specs, and if that one doesn't work, you can put a driver you know will work in there.

[VTypeV4]

I could do that.. I have an EV SRO 15L with an EVM-L recone kit which is in fine fettle and there's plenty of data on those..

Thanks Mr F, I'll have a think.

[VTypeV4]

Not meaning to Hijack my own thread but..

I read on another forum that the G15C was Celestions' lower power equivilant of the JBL D/E140..

Does this sound likely or simply hearsay?

[Mr. Foxen]

"Equivalent" doesn't mean much, this kind of dates from when everyone 'knew' a 15" speaker had a sound from it being 15", so equivalence might be no more than that.

[VTypeV4]

[quote name='Mr. Foxen' timestamp='1360886928' post='1978084']
"Equivalent" doesn't mean much, this kind of dates from when everyone 'knew' a 15" speaker had a sound from it being 15", so equivalence might be no more than that.
[/quote]

Ok man, cheers..

[bertbass]

My first ever 'real' bass setup was a Wem ER40 and a Wem Starfinder 1x15 cab and the cab had one of them thar Celestions in it, if that helps. Many years later I had a Wem 2x15 which was the same size cab but with 2 of those Celestions in it. Probably doesn't help that much after all.

[VTypeV4]

Thanks anyways Bert..

I'm gonna put it in my 1x15 Ashton cab and see how it performs in a reasonably large vented box vs the small sealed WEM.

Truth is, I'm not expecting miracles or 35 Hz (which would be a miracle!), just a pleasant and warm sounding speaker to use at home or to do a bit of old school recording with an SM57. I paid next to nothing for it but think it's;s a really cool looking old thing that could be put to good use.

Here are some pix I did of the repair job..

[IMG]http://i778.photobucket.com/albums/yy70/VTypeV4/Celcoil1_zpsd3204df8.jpg[/IMG]

[IMG]http://i778.photobucket.com/albums/yy70/VTypeV4/CelCoil2_zps861f06e2.jpg[/IMG]

[IMG]http://i778.photobucket.com/albums/yy70/VTypeV4/Celcoil3_zpsd4a4a3ad.jpg[/IMG]

[IMG]http://i778.photobucket.com/albums/yy70/VTypeV4/Celcoil4_zps3c55f509.jpg[/IMG]

I was surprised by how deep the voice coil iss, I expected it would be really short being only a 50w speaker. I guess the paper former is the limiting factor..