fleabag Posted April 28, 2014 Share Posted April 28, 2014 (edited) Since WinISD is over my head, being a dullard, I need some cab guru advice on cab improvements ( if any - maybe not ) I have a 2x10 with 2 Eminence BETA 10a's , well known here I suspect, but just in case, they're 250 watt 8 ohm, with the pair wired as a 4 ohm cab. Internal cab measurments are 560mm / 22" tall - 360mm / 14" width - 395mm / 15.5" deep Rear firing port is 95mm / 3.75" long and 95mm / 3.75" throat ( parallel , not tapered and no flare ) I'm wondering if another port would improve anything, since i cannot change the cab size. Or am i already getting the best out of it ? Thanks in advance TSP / Specs of the BETA 10a [IMG]http://i62.tinypic.com/214yxdu.jpg[/IMG] Edited April 28, 2014 by fleabag Quote Link to comment Share on other sites More sharing options...
JPJ Posted April 28, 2014 Share Posted April 28, 2014 Had a quick look at it in winisd and for that cabinet volume, adding a second port isn't going to do anything meaningful and the roll off below 100hz is fairly steep. Probably the best thing you could do (if you haven't already) is add some good acoustic wadding to the inside surfaces of the cab to cut down on the reflections and try and 'clean' things up a bit. [b]Note[/b]: use of the term 'clean' is not meant to imply any sort of acoustic engineering knowledge on the part of the author. Other acoustic engineers may offer more relevant advice Quote Link to comment Share on other sites More sharing options...
stevie Posted April 28, 2014 Share Posted April 28, 2014 I agree with JPJ. The only thing I would mention is that the cabinet seems to be tuned to 40Hz, which is on the low side. You will increase power handling a bit and maybe get a slightly punchier sound if you take the port out. A port length of 18mm should tune the cab to around 50Hz. My modeling program tells me you are exceeding xmax at around 100/150W. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted April 28, 2014 Share Posted April 28, 2014 You're not going to be able to do much better, if at all, with Beta 10s. They have limited low frequency output capability due to a short excursion capacity, xmax. 3mm is what I'd consider just adequate. 5mm or so is what you'll find in better quality drivers. One driver with 5mm xmax has nearly the same output capability as two with 3mm xmax. If your cab isn't making the grade you should be looking for a cab loaded with better drivers. Quote Link to comment Share on other sites More sharing options...
fleabag Posted April 28, 2014 Author Share Posted April 28, 2014 JP Stevie Bill - thanks for your input, much appreciated Presumably then, if were to leave the cab specs as they are, I simply cannot mount better X Max drivers, due to cab limitations, or can i mount better drivers if i changed the port dimensions ? I suspect that if i go for better drivers, i'd need better cabs to put them in, which is the worse case scenario for me, financially Quote Link to comment Share on other sites More sharing options...
ahpook Posted April 28, 2014 Share Posted April 28, 2014 [quote name='JPJ' timestamp='1398698073' post='2436681'] [b]Note[/b]: use of the term 'clean' is not meant to imply any sort of acoustic engineering knowledge on the part of the author. Other acoustic engineers may offer more relevant advice [/quote] Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted April 28, 2014 Share Posted April 28, 2014 [quote name='fleabag' timestamp='1398713652' post='2436923'] JP Stevie Bill - thanks for your input, much appreciated Presumably then, if were to leave the cab specs as they are, I simply cannot mount better X Max drivers, due to cab limitations, or can i mount better drivers if i changed the port dimensions ? [/quote]Knowing the prices on drivers in the UK you're usually better off to go with a good used cab than to replace drivers into an old cab. That way you can sell the old cab, rather than end up with a couple of used drivers to try to sell. Quote Link to comment Share on other sites More sharing options...
fleabag Posted April 28, 2014 Author Share Posted April 28, 2014 (edited) Good point I thought Emi Beta 10a's were quite popular though, so didnt envisage a problem shifting them on. I actually have 4 of them If i remember correctly, they were one of the BFM choices for Omni 10.5's , of which i've owned 2 of, and a Jack 210 which i owned. I sold the the pair of Omni 10.5's in favour of the Jack 210 bought on here, with the thought that I'd easily find another Jack 210 to partner it, but after a long wait, i never did find another, and didnt like my 15" Peavey partnering the single Jack 210, so got rid of both Edited April 28, 2014 by fleabag Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted April 28, 2014 Share Posted April 28, 2014 [quote name='fleabag' timestamp='1398719339' post='2437015'] I thought Emi Beta 10a's...were one of the BFM choices for... a Jack 210 which i owned. [/quote]They still are the entry level recommended driver, but the plans are specific in that regard, and note better options. Plus the horn loaded Jack gets quite a bit more out of them than a direct radiating cab will. Quote Link to comment Share on other sites More sharing options...
Diablo Posted April 28, 2014 Share Posted April 28, 2014 [quote]If your cab isn't making the grade you should be looking for a cab loaded with better drivers. [/quote] So very true of many things, often the cheapest, least grief and most effective way of upgrading anything is to sell it and buy a better one. Usually works for cabs, cars, blenders, toasters and lawnmowers too. Although I did once get 16bhp out of a 100cc two stroke mower motor. Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted April 28, 2014 Share Posted April 28, 2014 [quote name='Bill Fitzmaurice' timestamp='1398718866' post='2437008'] Knowing the prices on drivers in the UK you're usually better off to go with a good used cab than to replace drivers into an old cab. That way you can sell the old cab, rather than end up with a couple of used drivers to try to sell. [/quote] Bill I love the fact you post on here Quote Link to comment Share on other sites More sharing options...
fleabag Posted April 28, 2014 Author Share Posted April 28, 2014 [quote name='Bill Fitzmaurice' timestamp='1398721250' post='2437034'] They still are the entry level recommended driver, but the plans are specific in that regard, and note better options. Plus the horn loaded Jack gets quite a bit more out of them than a direct radiating cab will. [/quote] Yup, I peruse the BFM forums too, sporadically, and am aware of your advice re such matters, whether here or there. Perhaps with some luck ( or maybe ' miracle ' would be the right word ) I could find someone selling off 2 Jack 210 cabs without drivers Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted April 29, 2014 Share Posted April 29, 2014 You don't say what your 2x10 is, if it is a home brew then it isn't going to sell for anything much, the drivers would sell for more on their own. If it is a reasonably well known brand then you would probably get enough by selling it for that to be the cheaper route as everyone has said, there are some real bargains to be had used. If it is a reasonably well made home brew and you are determined to tinker anyway then there are better speakers. For £50ea the Beyma SM110 is a bargain, well made, good excursion though you'll have to wait for delivery at the moment as they are imported specially from Spain. For £60ea there are the Fane 10-300 pro's which i've used. Very strong controlled bass but very neutral top end so they lack sparkle. The eminence deltas are £65 here and are a bit better than the Betas but not as good IMO as the Beymas. For £95 you have the Celestion BN10's (neo speakers) and the Eminence basslites are £90. I'd go for the Beymas or the Celestions. So for £100 you can improve your cab and for £200 you could have quite a good cab with modern lightweight drivers. Hmmm I feel a purchase coming on, rather like those Celestions. You'd probably need to re-tune the ports and check the size of the cut out holes. Look to see what you could trade up to used and then decide Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted April 29, 2014 Share Posted April 29, 2014 Oh of course you might be able to improve the cab with some judicious stuffing and adding some bracing to the panels, the betas aren't great speakers but they aren't the worst either. Quote Link to comment Share on other sites More sharing options...
fleabag Posted April 29, 2014 Author Share Posted April 29, 2014 (edited) Cheers Phil - partly home brew, as they were ex Peavey TX 210, 18 mm ply but with the Beta 10a's fitted, tweeters removed Advice noted. So you think the cab size ( volume ) is not such a problem, (also add stuffing and bracing ) just maybe the port dimension may need attention , when fitting, say, the Beymas ? Edited April 29, 2014 by fleabag Quote Link to comment Share on other sites More sharing options...
stevie Posted April 29, 2014 Share Posted April 29, 2014 (edited) If you were to fit more powerful drivers such as the Beyma, another port of the same diameter would certainly help and is perfectly feasible technically. 18mm birch ply cab, properly built, braced (no need to go mad), internally damped, a pair of good quality Beyma drivers - not many commercial 2 x 10s will keep up with that. And it will cost you £100 plus the damping, bracing and plastic port. There is no other way of getting such a big bang for your buck - especially as you will certainly get a few bob for your cheapo Eminence 10s. I'd also suggest you fit Speakons if you have XLR inputs, as they're an easy swap. If you decide to go ahead, get back to me and I'll work out the length of the ports for you (or you can do it yourself in WinISD). One last thing, not all tens are the same size. Check with the manufacturer's spec sheet to make sure your driver will fit. Edited April 29, 2014 by stevie Quote Link to comment Share on other sites More sharing options...
fleabag Posted April 29, 2014 Author Share Posted April 29, 2014 Cheers stevie - sounds promising I like Phil's Beyma recommendation . Ok, so a quick check with the diameters and such and see if they'll fit, and if they do, i'll get some and flog the Betas, and faff about with the stuffing and bracing. Will definately take you up on the gracious offer of working out ports size - TVM ! Will get back to this thread when there's something to update you on. Thanks to all contributors for your kind help Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted April 29, 2014 Share Posted April 29, 2014 (edited) Great, that's the deal. free advice for telling us how it comes out. Edited April 29, 2014 by Phil Starr Quote Link to comment Share on other sites More sharing options...
fleabag Posted May 2, 2014 Author Share Posted May 2, 2014 Beymas ordered - could be 4 weeks , due to sporadic info, spanish postal system, and whether there might be some stock already in the UK. We'll see Might as well get on with the bracing and extra damping Quote Link to comment Share on other sites More sharing options...
paulmcnamara Posted May 2, 2014 Share Posted May 2, 2014 Try a Grammar Pad? Quote Link to comment Share on other sites More sharing options...
fleabag Posted May 2, 2014 Author Share Posted May 2, 2014 Sounds like snake oil Besides, i have castors on the bottom cab Quote Link to comment Share on other sites More sharing options...
fleabag Posted May 2, 2014 Author Share Posted May 2, 2014 (edited) Just a looksee inside, and there seems to be a lot of wadding already. Also, there's some bracing almost 3/4 of the way across the cab, attached to the baffle board and the back board, running horizontal, though it doesnt quite reach the other side ( No.3 ) but is quite thick - at least 15mm. If any bracing needed, i think i could put 2 pieces beneath each driver , full wdith ( No. 1 and 2 ) This pic showing more inside and how much wadding already there - only the back board seems to have any bareness Edited May 2, 2014 by fleabag Quote Link to comment Share on other sites More sharing options...
fleabag Posted May 2, 2014 Author Share Posted May 2, 2014 The previous owner , aende ( a member here - good lad too ) may have done some of the wadding though its possibly original Peavey. Maybe that baffle brace too Quote Link to comment Share on other sites More sharing options...
stevie Posted May 2, 2014 Share Posted May 2, 2014 (edited) You seem to have enough wadding but I'm surprised that the brace between the drivers isn't connected to the back of the cab - that's how it's normally done. The two places you've marked for additional bracing are spot on and you probably won't need any more. Edit: I clearly misread the description here......Of course the brace is connected to the back of the cab. Edited May 8, 2014 by stevie Quote Link to comment Share on other sites More sharing options...
fleabag Posted May 2, 2014 Author Share Posted May 2, 2014 Cheers stevie Yes it does seem weird that baffle brace only goes 3/4 of the way across--- it stops because of the port tube presumably. Although 15mm thick, the board is about 8" in width. Odd ! Its actually attached / glued / nailed ? to 3 sides, ( baffle board back board and one side board, which i didnt mention above but i will brace elswhere as you say, in those 2 places numbered Quote Link to comment Share on other sites More sharing options...
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