SWR Workingman 2x12" cab

[orangepeelneil]

Hi everyone,

 

I was planning to build my own 2x12” cab as I have load of ply,  but this came up locally and is much better than I could build plus I have no spare time right now.

 

It a SWR workingman 2x12” + horn, the baffle board, base and sides are ¾” ply and the back and top are particle board, so it’s not the lightest, however it’s on castors and easier to move than my Mark bass 4x10” due to compact size. I’ve disconnected the horn and made up a jack/speakon rear panel to replace the jack and horn switch.

 

It's loaded with 2 Celestion K12T-200 (and the horn) I don’t know these speakers? They are labelled custom for SWR 

it actually sounds fine, but I’m thinking probably lighter and more efficient/ higher power handing modern speakers would improve this cab, any recommendations?

 

I guess the cab needs modelling in WinISD and speaker options considered.

 

Cab internally is= 42cm H x 55cm W x 54cm H   127Litres

External = 46cm H x 58cm W c 58cm H

 

It has x2 ports 65mm, 100mm diameter.

 

Thanks Neil

Edited January 9, 2023 by orangepeelneil

[Bill Fitzmaurice]

My concern about the K12T-200 is xmax. I can't find specs on it, but the K12H-200TC xmax is only 2mm. That's half what I'd consider the minimum acceptable. It results in a real world mechanical power limit of 25 watts. One can only speculate if the K12T-200 xmax is that short, but given the age of it and knowing Celestion came very late to the party where real bass specific drivers are concerned I wouldn't want to assume otherwise.

Edited January 9, 2023 by Bill Fitzmaurice

[warwickhunt]

I've often been surprised when I've looked at the weight of various drivers.  Some 'neo' drivers are/were heavier than non-neo units; added to which the actual weight saving between some better spec units is minimal in the gross weight of drivers + cab.  I get that better spec drivers would be beneficial but if the weight isn't being shed, will that be an issue later on (the resale of a cab with good drivers in is rarely recouped).    

[orangepeelneil]

Many thanks for the reply @Bill Fitzmaurice

 

Yes I couldn't find much info either on these speakers, I will mail Celestion for specs. 

 

I've seen these speakers being advertised as guitar speakers as they have lots of headroom.

Maybe these have more appeal to guitarists, dunno - will get the spec and see what you guys recommend. 

 

Neil 

 

 

Edited January 9, 2023 by orangepeelneil

[ebenezer]

Nice cab!.....this was the cheaper version of the cab called " BIG FOOT ".....that cab had bag end 12s and a le-son tweeter.....were it me, and it isn't, i would install eminence deltalite....I know you should model the cab, but i think these would suit a broad range of cab sizes etc

[agedhorse]

I would suggest cleaning up the wiring and whatever crossover it’s supposed to have back to factory condition and listen to it before assuming anything. You might be pleasantly surprised.  

[orangepeelneil]

18 minutes ago, agedhorse said:

I would suggest cleaning up the wiring and whatever crossover it’s supposed to have back to factory condition and listen to it before assuming anything. You might be pleasantly surprised.  

Yes, its a fairly decent sounding cab but I've only tried it at low practice volumes .  I wasn't sure if the Celestion were stock, but it appears so. 

I've always liked SWR equipment, great quality kit. 

 

[Bill Fitzmaurice]

K12H-200TC

3 hours ago, orangepeelneil said:

I've seen these speakers being advertised as guitar speakers as they have lots of headroom.

If the xmax spec is 2mm they have more headroom than most guitar drivers, the Greenback is 0.7mm, but the rest of the specs if similar to the K12H-200TC aren't well suited to guitar. I'd be very wary, as even the BN-12 300S has only 2.5mm xmax.

[stevie]

The Celestion K series, as far as I can remember, was a budget range of PA speakers. One of my databases gives 1.5mm as the xmax for this driver. Even taking into account Celestion's more conservative xmax specification, it would be OK in a PA cab (with a sub) but would not go very loud in a bass guitar cab - certainly compared with more modern drivers. It's also got to be at least 25 years old.

[Balcro]

Swapping out the existing Celestions for a pair of neodymiums might only save you about 2.5lbs in weight for each drive unit. Not the best bonus for a possible outlay of £250!

I agree with the comments from "agedhorse". If it works well without any obvious scraping, roughness or rattles  then it's definitely worth a punt.

Many neo speakers seem to have great efficiency, i.e they're a lot louder for a given input than the ferric equivilants. Celestions' current 12" line-up shows the difference. The BN300S that Bill mentioned is 4-5 dB louder than the Celestion Pulse 12 from 400Hz & upwards, but the Pulse has a very strong thump around 80-140Hz - see Celestions' own frequency response graphs. Even the few lines of descriptive text for each speaker hint at the overall sound.

https://celestion.com/product/pulse12/

https://celestion.com/product/bn12-300s-8/

If the drive units in the SWR ever fail, then a pair of Pulse 12's will fit the bill nicely (mounting hole size and diameter permitting). The sound will never be the same as the original but a bit of amplifier bass & middle eq correction should sort things out.

PS. I wouldn't recommend the BN300s in that cabinet. Other 12" neos may be more suitable.

[Bill Fitzmaurice]

1 hour ago, Balcro said:

The BN300S that Bill mentioned is 4-5 dB louder than the Celestion Pulse 12 from 400Hz & upwards, but the Pulse has a very strong thump around 80-140Hz - see Celestions' own frequency response graphs.

That has nothing to do with the magnet material. A higher Fs and other factors give the BN300S higher sensitivity in the mids, but also result in less low frequency extension. One of the highest sensitivity drivers ever made was JBL D130, which had an AlNico magnet. It also had very poor low frequency response, but that was an acceptable trade off in 1948, when 25 watt amps were state of the art. It was also designed some 17 years before the advent the Thiele/Small specs. Only after that did designers realize that the main way to get higher sensitivity, more magnetic flux, doesn't increase sensitivity linearly across the full audio spectrum. It tilts it to the mids and highs. Where electric bass is concerned you want to compare sensitivity where it matters most, 50 to 80Hz. You can't do that with manufacturer data sheet charts, as they are measured with the driver mounted in a wall, and don't show the results in an enclosure. You need to use speaker modeling software to do that.

[silverfoxnik]

I had one of these cabs for a while about 12, 13 years ago.

 

It sounded pretty good to me and was great for rehearsals and small pub gigs at the time. 

[Balcro]

19 hours ago, Bill Fitzmaurice said:

That has nothing to do with the magnet material. A higher Fs and other factors give the BN300S higher sensitivity in the mids, but also result in less low frequency extension. One of the highest sensitivity drivers ever made was JBL D130, which had an AlNico magnet. It also had very poor low frequency response, but that was an acceptable trade off in 1948, when 25 watt amps were state of the art. It was also designed some 17 years before the advent the Thiele/Small specs. Only after that did designers realize that the main way to get higher sensitivity, more magnetic flux, doesn't increase sensitivity linearly across the full audio spectrum. It tilts it to the mids and highs. Where electric bass is concerned you want to compare sensitivity where it matters most, 50 to 80Hz. You can't do that with manufacturer data sheet charts, as they are measured with the driver mounted in a wall, and don't show the results in an enclosure. You need to use speaker modeling software to do that.

 

 

I said many neos not all neos. The comment was illustrative not ultra precise and referred to the BN300S for comparison, only because it had been mentioned in earlier posts.

I had already done comparative modelling with winISD before posting, hence my comments on the  frequency response spectrum.  ("The BN300S that Bill mentioned is 4-5 dB louder than the Celestion Pulse 12 from 400Hz & upwards, but the Pulse has a very strong thump around 80-140Hz ") . These comments would not ring true from a look at the graphs on Celestions' web-site which under-represent bass performance. Perhaps I should have said "see the attached winISD graphs", not Celestions' graphs.

My words: "Even the few lines of descriptive text for each speaker hint at the overall sound".

CELESTION:- BN12300S.  Also available in 4Ω the BN12-300S is a 12 inch bass guitar speaker that delivers clear well-balanced bass so you can be confident in your performance whether holding the line or punching through the mix.

CELESTION:-Pulse 12. For bass players demanding well-defined clarity and stunning articulation together with a rich full tone PULSE12 bass speakers deliver an ideal combination of responsiveness and rock solid low end.

This combination of vagueness & hyperbole marketing speak from Celestion is a roundabout way of saying the folowing -

"A higher Fs and other factors give the BN300S higher sensitivity in the mids, but also result in less low frequency extension". "Only after that did designers realize that the main way to get higher sensitivity, more magnetic flux, doesn't increase sensitivity linearly across the full audio spectrum. It tilts it to the mids and highs".

 

 

 

Edited January 12, 2023 by Balcro