stevie Posted December 10, 2018 Author Share Posted December 10, 2018 I'll make some more measurements and post them tomorrow to give you all a better picture of how the cab performs. On the matter of flat pack cabs, I know that some of you are keen to get hold of some, but despite spending a lot of time on it, I'm struggling to find a competent cab builder. The ones I've been talking to either don't seem to know what they're doing (one was unable to source poplar ply!), or are so slow in responding to messages that they give the impression of being very inefficient. There are still a few possibles left on my list, but I'd prefer to deal with a company that's not half way across the country. The other option that's open to us is to have the CNC plans prepared so that any competent woodworking company with a CNC machine can work with them. Phil tells me that there are some Basschatters who produce those files for a living. If so, I'd appreciate if you would help us out. Marco (Ghostbass) is busy preparing technical drawings of the cab and I can supplement this with drawings of all the components, hole sizes, etc. that you would need. Can anyone help? Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted December 10, 2018 Share Posted December 10, 2018 (edited) 3 hours ago, stevie said: I'll make some more measurements and post them tomorrow to give you all a better picture of how the cab performs. On the matter of flat pack cabs, I know that some of you are keen to get hold of some, but despite spending a lot of time on it, I'm struggling to find a competent cab builder. The ones I've been talking to either don't seem to know what they're doing (one was unable to source poplar ply!), or are so slow in responding to messages that they give the impression of being very inefficient. There are still a few possibles left on my list, but I'd prefer to deal with a company that's not half way across the country. The other option that's open to us is to have the CNC plans prepared so that any competent woodworking company with a CNC machine can work with them. Phil tells me that there are some Basschatters who produce those files for a living. If so, I'd appreciate if you would help us out. Marco (Ghostbass) is busy preparing technical drawings of the cab and I can supplement this with drawings of all the components, hole sizes, etc. that you would need. Can anyone help? Read this and got me wondering about poplar ply ...according to the web my local Woodyard stocks something called Banova plus which is balsa plywood with hardwood outer -designed for lightweight furniture and trade stands it seems - no idea how much it costs of if suitable but sounds light! Edit: not as stiff as poplar ply, but stiffer than mdf https://d371dyuip757b1.cloudfront.net/downloads/Banova-Technical_Processing_Guide_V.online-download.pdf Edited December 10, 2018 by LukeFRC Quote Link to comment Share on other sites More sharing options...
RichardH Posted December 11, 2018 Share Posted December 11, 2018 (edited) I have a contact on an audio website who does produce hifi speaker flatpack kits, I could ask him. However, i suspect it won't be cheap. I suspect the best way to approach it would be to ask for a batch of kits to be made up. That means someone needs to stump up a load of ££££ up front. Without enquiring, I would suspect we would be talking a couple of hundred quid for the setup and cutting time etc. Then there's the material costs. Also remember that most CNC cutting means waste, so we'd need to be sure that you can still get two kits out of one panel, otherwise the costs go up... Half way house would be just having the panels supplied cut to size, though that would require people to cut the baffle and handle holes etc. If someone was so inclined, they could make router templates to create the the relevant cuts, but they would then need to get involved in producing the kits and shipping them out etc. Depends how far down the line people want these flatpacks to be. Unless you can just throw a sheet of ply onto a CNC machine, then it starts getting very time consuming and therefore expensive. I think the other thing to emphasise is that unless the flatpack is cut with rebates etc to help panel location, then anyone assembling them will still need a range of tools etc - it's still not going to be a half hour "lego" assembly job. Final thought for the morning (and no disrespect to those expressing an interest), I suspect that the actual number of people who put the money down for a kit will be fewer.... and therefore the costs get higher per kit. I am in the midst of moving house (hopefully!!) so can't get involved in flat packs at the moment. However, once moved, I would POTENTIALLY consider the half way house thing, where I get a load of sheets of ply cut as per the cutlist at Avon plywood and then route the baffle holes, top handle rebate and rear panel speakon holes, so that all the tricky stuff is done (though the whacky brace shapes might be another thing to consider). Edited December 11, 2018 by RichardH 1 Quote Link to comment Share on other sites More sharing options...
stevie Posted December 11, 2018 Author Share Posted December 11, 2018 16 hours ago, LukeFRC said: Read this and got me wondering about poplar ply ...according to the web my local Woodyard stocks something called Banova plus which is balsa plywood with hardwood outer -designed for lightweight furniture and trade stands it seems - no idea how much it costs of if suitable but sounds light! That got me really excited this morning, Luke. I researched it and it looks like the 18mm version of that ply would have a similar stiffness to the 15mm poplar we're using at the moment. Although there's a cost penalty, it would cut the weight of our cab by 3 KG. That's a lot! So I phoned them up. The material is made by a Swiss company and, according to the UK supplier you mentioned, they have decided not to export to the UK in the future. They weren't sure why. Once the UK company has sold off its existing stocks, you won't be able to get hold of it any more. Interestingly, they said they were trialling an alternative plywood. That one is actually a bit stiffer than poplar, but would still cut the weight of our cab by about 1.5kg. I'm going to keep my eye on that, but I'd rather not take the risk of using an unkown type of plywood for the time being. All good information though. 1 Quote Link to comment Share on other sites More sharing options...
stevie Posted December 11, 2018 Author Share Posted December 11, 2018 8 hours ago, RichardH said: I have a contact on an audio website who does produce hifi speaker flatpack kits, I could ask him. However, i suspect it won't be cheap. I suspect the best way to approach it would be to ask for a batch of kits to be made up. That means someone needs to stump up a load of ££££ up front. Without enquiring, I would suspect we would be talking a couple of hundred quid for the setup and cutting time etc. Then there's the material costs. Also remember that most CNC cutting means waste, so we'd need to be sure that you can still get two kits out of one panel, otherwise the costs go up... Half way house would be just having the panels supplied cut to size, though that would require people to cut the baffle and handle holes etc. If someone was so inclined, they could make router templates to create the the relevant cuts, but they would then need to get involved in producing the kits and shipping them out etc. Depends how far down the line people want these flatpacks to be. Unless you can just throw a sheet of ply onto a CNC machine, then it starts getting very time consuming and therefore expensive. I think the other thing to emphasise is that unless the flatpack is cut with rebates etc to help panel location, then anyone assembling them will still need a range of tools etc - it's still not going to be a half hour "lego" assembly job. Final thought for the morning (and no disrespect to those expressing an interest), I suspect that the actual number of people who put the money down for a kit will be fewer.... and therefore the costs get higher per kit. I am in the midst of moving house (hopefully!!) so can't get involved in flat packs at the moment. However, once moved, I would POTENTIALLY consider the half way house thing, where I get a load of sheets of ply cut as per the cutlist at Avon plywood and then route the baffle holes, top handle rebate and rear panel speakon holes, so that all the tricky stuff is done (though the whacky brace shapes might be another thing to consider). It's nice to see some community input. Thanks, Richard. However, it looks as if I may have cracked the flat pack issue. I don't want to speak too soon, but will post more details when I have firm details. Quote Link to comment Share on other sites More sharing options...
stevie Posted December 11, 2018 Author Share Posted December 11, 2018 (edited) For those who like to roll their own, here's a layout for the crossover. Read together with the circuit diagram I posted earlier. I think that building a crossover might have been a step too far for a lot of people last time. So.....this time, I'm prepared to build and test a quantity of crossovers to get the ball rolling. All you'll have to do is screw the board down inside the cab and connect the wires. The six connections you can see on the bottom of the board are screw connectors for the wires. I'll precut the wires to size and crimp the connectors so that you won't have to solder anything. I'll even include a Speakon. As long as you cover the cost of the components, I'm happy. I'll do this for the first ten. Then you're on your own. If the flat packs work out, I'll be using a local CNC company. So I'll be able to collect and send a flat pack and a finished crossover out together to those wishing to build them, which will save on carriage. Building a crossover on a plywood board is a bit of a time consuming exercise. So if we have anyone out there who can produce fibreglass PCBs in small quantities (milled would be OK), please make yourself known. Edited January 30, 2019 by stevie 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted December 14, 2018 Share Posted December 14, 2018 What are you powering the cabs with? And how much power/how sensitive are they? I was always tempted to build a fearful - but was kinda put off by the whole tendency for folk to use massive high wattage amps Quote Link to comment Share on other sites More sharing options...
stevie Posted December 15, 2018 Author Share Posted December 15, 2018 I'm using an Ashdown Rootmaster 500 at the moment. The driver itself is quite sensitive. From about 80 Hz up, It's at least a couple of dB more sensitive than the Kappaliter 12LF used in the Fearful and others. I've modelled them both in our cab. Blue is the Kappalite. Both drivers will go lower in a larger cabinet. Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted December 15, 2018 Share Posted December 15, 2018 (edited) 2 hours ago, stevie said: I'm using an Ashdown Rootmaster 500 at the moment. The driver itself is quite sensitive. From about 80 Hz up, It's at least a couple of dB more sensitive than the Kappaliter 12LF used in the Fearful and others. I've modelled them both in our cab. Blue is the Kappalite. Both drivers will go lower in a larger cabinet. What kind of amp power would you recommend? Edit: I use a walkabout so only have 300-400w into 4 ohms Edited December 15, 2018 by LukeFRC Quote Link to comment Share on other sites More sharing options...
Muzz Posted December 15, 2018 Share Posted December 15, 2018 Just on the Walkabout thing; I have one, and use it with a BF Super Twin (2x12), and I can confirm with a cab with good sensitivity, 'only' 300-400w is plenty for a rawk band with 2 Marshall 100w/412s and a shed-building drummer.... Perhaps 1x12 might not be enough, but 2x12s definitely is... 😀 Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted December 18, 2018 Share Posted December 18, 2018 The Walkabout is rated at 165W into 8 ohms. I would guess that that would give about 118B with the Faital Pro driver. I will model; it soon but I am up to my ears at the moment. Quote Link to comment Share on other sites More sharing options...
stevie Posted December 20, 2018 Author Share Posted December 20, 2018 Luke, this cab is aimed at the owner of the newer class D amps producing 500W into 4 ohms and 300W into 8 ohms. Unless you run your amp flat out, there's not a huge difference between 300W and 165W - so I suspect you'd be fine. This cab will certainly go as loud with your amp as any other 12" cabinet out there. It will obviously not be as loud as a 2x12" 4-ohm cab though. 1 Quote Link to comment Share on other sites More sharing options...
LukeFRC Posted December 21, 2018 Share Posted December 21, 2018 17 hours ago, stevie said: Luke, this cab is aimed at the owner of the newer class D amps producing 500W into 4 ohms and 300W into 8 ohms. Unless you run your amp flat out, there's not a huge difference between 300W and 165W - so I suspect you'd be fine. This cab will certainly go as loud with your amp as any other 12" cabinet out there. It will obviously not be as loud as a 2x12" 4-ohm cab though. Hmmm so different amp, two of them or I resist this rig changing GAS... Quote Link to comment Share on other sites More sharing options...
stevie Posted December 21, 2018 Author Share Posted December 21, 2018 I think you'll be surprised how potent this little cab is. If you wait until after the New Year, I'll send you mine to try. Keep it for a couple of weeks and decide for yourself. Then send it back to me. My band is quiet in January and I have a spare cab anyway should a surprise gig happen. 1 Quote Link to comment Share on other sites More sharing options...
Balcro Posted December 21, 2018 Share Posted December 21, 2018 (edited) Hi LukeFRC, I can confirm chienmortbb's (Tuesday post) earlier estimate of "how loud it will go". Just ran winISD in auto mode - it sets the volume @ 69.81 litres. The following are basic & theoretical figures without fine tuning, nor is there reference to the actual volume of stevie's cab:- 165w input gives a maximum SPL of 119dB from 80Hz upwards!! xMax is only exceed below 37Hz at which point the output is 108.5dB. There's no arguing with stevie's assertion that "this cab will certainly go as loud with your amp as any other 12" cabinet out there." No discernible difference in output between 165w & 300w - the graph lines overlay each other. Putting 2 drivers in - just for fun- & upping the volume to 130 litres (still with 165watts) gives a potential 124.7db!! Balcro. Edited December 21, 2018 by Balcro 1 Quote Link to comment Share on other sites More sharing options...
stevie Posted December 23, 2018 Author Share Posted December 23, 2018 The cab's slightly smaller than the WinSD suggestion, Balcro - so power handling is a bit better than you've calculated. Plus, the port is a very efficient design that keeps going when most others are suffering from bad compression. Quote Link to comment Share on other sites More sharing options...
3below Posted December 23, 2018 Share Posted December 23, 2018 (edited) On 14/12/2018 at 23:01, LukeFRC said: What are you powering the cabs with? And how much power/how sensitive are they? I was always tempted to build a fearful - but was kinda put off by the whole tendency for folk to use massive high wattage amps I have built a fearful 15/6/1 clone in conjunction with Shermann audio who did it as a one off / explore the possibilities. It is a seriously good cab, however it does have an appetite for watts, I find 700W into 8 ohms adequate. Edited December 23, 2018 by 3below spag Quote Link to comment Share on other sites More sharing options...
stevie Posted December 30, 2018 Author Share Posted December 30, 2018 A 15/3 should be fairly loud even with a modest amp. Did you find you needed 700W? Did the guys at Shermann measure the end result? Quote Link to comment Share on other sites More sharing options...
Jimrs2k2 Posted January 7, 2019 Share Posted January 7, 2019 Just referring to the fearful comment, yes you can pump 700 watts in them all day but its definitely not required. I have been using a 15/6/1 for ten years and found 3 / 500 plenty, however I have experimented with 3k power amps and it was completely stupid when paired with the matching sub. That saying I am very impressed with the 12 cab it is really very very good. Quote Link to comment Share on other sites More sharing options...
funkle Posted January 24, 2019 Share Posted January 24, 2019 Any word on flat pack progress? I remain interested... 1 Quote Link to comment Share on other sites More sharing options...
stevie Posted January 25, 2019 Author Share Posted January 25, 2019 It's been a hectic month for me work-wise, and I haven't been able to spend much time on this project. However, I have located a CNC company prepared to supply us at a reasonable cost, which is a big step forward. RichardH has been doing sterling work finalising the drawings, building on Ghostbass's original work, and we should be putting the final drawings up very soon for those wishing to use their local wood merchant. I'll be back on the job again within the next few days to organise a prototype flat pack, and I'll keep you informed of events. I'm hoping to have flat packs ready once this awful cold spell has finished, which is probably good timing. 1 2 Quote Link to comment Share on other sites More sharing options...
funkle Posted January 25, 2019 Share Posted January 25, 2019 (edited) Thanks kindly for all the hard work, Stevie and everyone. Edited January 25, 2019 by funkle Quote Link to comment Share on other sites More sharing options...
stevie Posted January 31, 2019 Author Share Posted January 31, 2019 (edited) Here are the drawings and cutting list. A big thank-you to RichardH (and Ghostbass) for doing these. I still have a bit more tweaking to do to the crossover - nothing major - and we'll add the final crossover to the PDF soon. BC112-v3 drawings v 4.pdf Edited February 15, 2019 by stevie 1 2 Quote Link to comment Share on other sites More sharing options...
RichardH Posted January 31, 2019 Share Posted January 31, 2019 (edited) I was only able to do these because of the work that others had done before - I have just been chopping things around and rejigging. Just spotted a slight glitch in the cutting sequence on the cutlist sheet, but will correct when the final crossover is added. Edited February 5, 2019 by RichardH Quote Link to comment Share on other sites More sharing options...
stevie Posted January 31, 2019 Author Share Posted January 31, 2019 Two G braces in the cutting list? Quote Link to comment Share on other sites More sharing options...
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