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View Full Version : 'Re-cabineting' C56 Dorians w/S1 system



jimbofish
01-15-2014, 10:53 PM
Got this pair of C56 Dorians a few years ago. They have the S1 system - LE14/LE175/LX10. Replaced the surrounds and the paper caps in the crossover. They sound wonderful!

The cabinets, however, are a disaster. Several of the corners are completely chewed/bashed away. The baffle board and the bottom are badly cracked, probably from someone dropping them. Even the stone tops have chips and gouges in them. 6121161212

So, the time has come to build new cabinets for them. Obviously, I could just replicate the existing cabs. I see from the catalogs here that the same S1 system was also used in the C51 and C61 speakers. The main difference, other than the style and finish, is the internal volume is larger, 3.5 cu' vs 2.0cu'. Space is not a problem so the larger cabinets are an option for me.

My first question is, what advantage should I expect from the extra volume? I'd expect extended bass response, but I'm not that knowledgeable about speaker design. It would cost more and take up more space to build the larger cabs, but I'd like to know beforehand if the improvement, if any, will be worth the effort. I haven't found any specs that would indicate the difference in frequency response.

So, what experience does anyone here have with both sizes of the S1 system that they'd care to share?

John W
01-16-2014, 08:16 AM
Those cabinets certainly have seen better days.

Do a search on-line for a program called WinISD. It is fairly easy to use and has built in parameters for the LE14A. You can quickly experiment with different box sizes and tuning frequencies and plot on a graph the difference in response.
It will also calculate the port length for you.

I think the same basic footprint, and shape but 6 or 8 inches taller might be something to consider – keeping the stone top.

jimbofish
01-16-2014, 09:30 AM
You reminded me that I already have WinISD on this computer. It's an old version though, beta it says. I'll try putting the C56 and C61 dimentions in and see what it says.

jimbofish
01-17-2014, 09:15 AM
Well, I've been playing with WinISD without much gain. AFAICT the C56 speakers I have now should have ridiculously long ports or crazy response curves. I don't think it's going to be much help at this point.

Are there published specs for the cabinet/systems in question? I haven't found any in the library here.

macaroonie
01-17-2014, 11:44 AM
Out of curiosity I had a look in WIN ( beta version ) First option it gives is tuned to 50 hz but after a bit of mucking about I got to this.

140litre box
tuned to 30hz
port is 4" dia , 98mm long

That volume is Just shy of 5 cu ft. If those figures hold true I would advocate building a taller box with a narrower baffle , say 14" , but deeper front to back.
This will raise the drivers more to ear height and if you centralise all the bits and bobs your imaging will improve.
I'll leave it to you to do the aesthetic stuff.

PS can't account for what happens when you replace the Lansalloy with foam if that's what you plan. Probably not a lot. Others may know more about this.

As a starting point 350wide 400 deep 1000 tall gives you exactly 140 litre but that's not including cabinet wall thickness

M

jimbofish
01-18-2014, 09:22 AM
Appreciate the efforts with WinISD, but I'm not looking to re-design a cabinet, just plan to use the existing dimensions for the larger C51/61 that JBL already used for this system when they were current. I suspect there is a way to show that with WinISD but I'm not having any success.

So I'm really just asking for experiences or references to what I can expect by moving to the larger cab. If the difference is slight, it may not be worth the extra space and material. I do know the old cabinets are leaking from the joints and cracks and a new C56 sized cab should be an improvement.

BTW the surrounds have already been replaced with foam.