Phil Starr Posted November 13, 2021 Share Posted November 13, 2021 13 hours ago, The fasting showman said: Hi Phil, the Faital Pro PR12 300 arrived today and it sounds great from what I can tell at home, very balanced sound across the neck and will be ideal for pub gigs where you've got the speaker firing into your back on a cramped stage (stage if you are lucky). I've still got some faffing to do with finishing off but I'll PM you the pics when sorted. It's an epic Covid related, toolbox stuck at the house of my Covid stricken boss, a £23 6ft x 2ft 12mm ply hyperbolic paraboloid from Wickes, hand cut panels with that saw you use to cut the end off a tube of silicon...but we got there in the end! Thanks for a great design, Martin Thanks for that. I'm always ridiculously pleased when a build makes it's first sounds, even more so when it is someone else's. That Faital is a nice driver but recommending something when other people's tastes and needs vary so much is always a bit of a risk. Really looking forward to seeing the pics, 2 Quote Link to comment Share on other sites More sharing options...
The fasting showman Posted November 14, 2021 Share Posted November 14, 2021 On 13/11/2021 at 09:12, Phil Starr said: Thanks for that. I'm always ridiculously pleased when a build makes it's first sounds, even more so when it is someone else's. That Faital is a nice driver but recommending something when other people's tastes and needs vary so much is always a bit of a risk. Really looking forward to seeing the pics, Just PM'd you my O level woodwork project Phil! Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted November 15, 2021 Share Posted November 15, 2021 It's looking good, time to show the world.😉 1 Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted November 23, 2021 Share Posted November 23, 2021 I've been pondering something.... If you know the ID of a circular port and the length of the port, can this be regurgitated into a shelf port? I've had a play with WINISD and a calculator and I can do the maths, but wondered if there were more factors that would influence the change from one type to another? (keeping shelf a good distance away from back wall of enclosure, wadding etc etc) I've been mulling over building the latest 12" basschat cab, but possibly with a shelf port and maybe even in a kickback style enclosure (Fearless F112 style) Or should I just keep quiet and build it as per plans? 😁 Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted November 25, 2021 Share Posted November 25, 2021 (edited) On 23/11/2021 at 15:32, GlamBass74 said: I've been pondering something.... If you know the ID of a circular port and the length of the port, can this be regurgitated into a shelf port? I've had a play with WINISD and a calculator and I can do the maths, but wondered if there were more factors that would influence the change from one type to another? (keeping shelf a good distance away from back wall of enclosure, wadding etc etc) I've been mulling over building the latest 12" basschat cab, but possibly with a shelf port and maybe even in a kickback style enclosure (Fearless F112 style) Or should I just keep quiet and build it as per plans? 😁 I should probably let @stevieanswer this but I well remember the long and detailed discussions about the benefits of various port configurations. to precis, flat sided ports work less well than round ones and a single large port works better than multiple round ports. Round ports also allow for fine tuning. Edited November 25, 2021 by Chienmortbb Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted November 25, 2021 Share Posted November 25, 2021 On 23/11/2021 at 15:32, GlamBass74 said: I've been pondering something.... If you know the ID of a circular port and the length of the port, can this be regurgitated into a shelf port? I've had a play with WINISD and a calculator and I can do the maths, but wondered if there were more factors that would influence the change from one type to another? (keeping shelf a good distance away from back wall of enclosure, wadding etc etc) I've been mulling over building the latest 12" basschat cab, but possibly with a shelf port and maybe even in a kickback style enclosure (Fearless F112 style) Or should I just keep quiet and build it as per plans? 😁 Certainly not! The original Mk1 prototype was a slot ported design. I shelved that (see what I did there ) because I needed a lot of clamps to make it and I wanted something that could be built with the sort of tools people might have at home. The whole point of publishing these designs and running the incredibly long threads is that you are home building and you can either copy the recipe and get the same result of a built and tested design or you can follow the ideas and make something that suits you. We are happy to discuss the likely implications of any changes you propose and that will help de-mystify the whole process. Essentially if the port has the same cross sectional area and length then it will be tuned to the same frequency. We did find in developing the Mk3 that port shape influences how early port noises start to happen. A single large circular port being the ideal as far as port noises are concerned. Turbulence occurs initially at the edges of the port. A slot port however will stiffen the box so you gain and lose something. Turbulence is something easy to get with test signals in the workshop but not something I've experiences noticeably at a gig. If you are building a 2 way design with a horn then I would keep the overall volume of the cab the same. Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 12, 2021 Share Posted December 12, 2021 MK3 started taking shape today. Jigsaw has been busy 😁 Can I ask.... If I wanted to build a tweeter less cab to go under the full range version, what would I need in the way of crossover / filter? Thanks. Jon 3 Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted December 12, 2021 Share Posted December 12, 2021 Hi Jon, @stevie might be along later to help but you have two practical considerations. The obvious crossover is to build an identical low pass filter to the one in the cab you are building which will mean both your 12's will be operating over the same frequency so you'll have the same bass but 3-6db more of it. What you will hear on top of the speaker with the horn raised nearer your ears won't have changed much but the audience will be getting a bass dominated sound. The other approach would be no crossover at all. This would mean you'd have all of the sound of a 1x12 without a horn. Up to the crossover this would be good two identical speakers in phase making a noticeably bigger sound but above the crossover point the output of the lower can would overlap with the tweeter so that at some frequencies there would be cancellation and at others reinforcement. All that means that the combination wouldn't sound the same as the original cab and would no longer be FRFR. the only way to find out how it sounds would be to try it. I'm not saying it would be bad, just different. Barefaced and the like often advise the mixing of cabs and some people like it. They probably like making extra sales. I'd wait until you have tried the cab you are building. It will go extremely loud and will comfortably match the drums, you may not need an extra cab. As you are self building you could leave space for the horn in the second cab s you could add it later if you didn't lke the combination or you could build two Mk3's but have a switch to cut the horn when it suited you. But try the cab first, you might be pleasantly surprised at the volume 1 Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 12, 2021 Share Posted December 12, 2021 Thanks Phil. Was probably getting ahead of myself. Really enjoyed the build today. Normal use a router, but kept it simple with a jigsaw today. Came out a treat! Jon 1 Quote Link to comment Share on other sites More sharing options...
stevie Posted December 13, 2021 Author Share Posted December 13, 2021 (edited) I don't really have a lot to add to what Phil said. I'm not a big fan of doubling up on cabs. I appreciate that people like a "wall of sound" behind them, but it tends to emphasise the low end at the expense of everything else. I would definitely advise against doubling up on the tweeter in the BCIII system, however, as two widely spaced tweeters is a sure-fire recipe for comb filtering and won't add anything useful. As Phil said, this is a really loud system. I can't see many situations where a second would be needed. Also, the compression driver configuration means that you don't need to raise the cabinet off the ground to hear it. The full range of the bass reaches your ears standing from about 1 metre in front of the cab. It's nice to see another one of these coming together. Edited December 13, 2021 by stevie Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 13, 2021 Share Posted December 13, 2021 Cheers Stevie I will go with 1 cab. I think the only reason I was so keen was because the 8x4 sheet gave me 2 complete cabs! I am really looking forward to hearing it. I will add a few more pictures as things progress - and try not to ask too many silly questions Jon Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 14, 2021 Share Posted December 14, 2021 Braces in today. T Nuts fitted into baffle. Going nicely 3 Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 15, 2021 Share Posted December 15, 2021 Quick check before work this morning Braces dried up nicely Laid some panels on to get an idea of size of the beast I'm getting rather excited 😍 2 Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted December 15, 2021 Share Posted December 15, 2021 The pile of tools on the left looks like my workshop, the neatly racked spanners not so much Good to see it coming along 2 Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted December 15, 2021 Share Posted December 15, 2021 On 13/12/2021 at 11:40, GlamBass74 said: Cheers Stevie I will go with 1 cab. I think the only reason I was so keen was because the 8x4 sheet gave me 2 complete cabs! I am really looking forward to hearing it. I will add a few more pictures as things progress - and try not to ask too many silly questions Jon There is no such thing as a silly question. only silly answers. 1 Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 15, 2021 Share Posted December 15, 2021 I must admit that I felt awful when I looked the photo online rather than on my phone - What a dump! (the whole garage is like it... and my shed.... and trailer.... and greenhouse) I think i've inherited this trait from my recently departed and massively missed father ☹️ We were never the tidiest of people when we got our teeth into a project I always clean down between jobs, but this one seems to be taking the michael somewhat Why do I need a battery for a vespa on the bench? Right.... next bench pic will be MUCH tidier ☺️ I've just ordered the wood for a BFM Omni15 Tallboy too 😲. I feared that I may have this one done before the christmas break (definitely need a project to get my hands out of the quality street tin..) Onwards and upwards! 2 1 Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted December 15, 2021 Share Posted December 15, 2021 I have two chainsaws awaiting re-built carburettors on mine. Plus the control unit for an Ariston boiler which has been scrapped (but the relays might come in handy) 2 Quote Link to comment Share on other sites More sharing options...
GlamBass74 Posted December 15, 2021 Share Posted December 15, 2021 ahhh..... the old "come in handy" eh? ☺️ Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted December 15, 2021 Share Posted December 15, 2021 3 hours ago, Chienmortbb said: There is no such thing as a silly question. only silly answers. I beg to differ. Example: How many pieces of pizza can you fit in a trombone? Quote Link to comment Share on other sites More sharing options...
Stub Mandrel Posted December 15, 2021 Share Posted December 15, 2021 My workshop is in a container. I now have a date for moving it into its new home. Quote Link to comment Share on other sites More sharing options...
nekomatic Posted December 15, 2021 Share Posted December 15, 2021 1 hour ago, Pea Turgh said: I beg to differ. Example: How many pieces of pizza can you fit in a trombone? Well that’s just a silly example. I mean, you haven’t even said how big the pieces of pizza are. 1 Quote Link to comment Share on other sites More sharing options...
Pea Turgh Posted December 15, 2021 Share Posted December 15, 2021 28 minutes ago, nekomatic said: Well that’s just a silly example. I mean, you haven’t even said how big the pieces of pizza are. Come on, they’re twice as big as from the middle to the edge, obvs! Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted December 15, 2021 Share Posted December 15, 2021 2 hours ago, Pea Turgh said: I beg to differ. Example: How many pieces of pizza can you fit in a trombone? Answer: It depends how well you roll them! Quote Link to comment Share on other sites More sharing options...
Chienmortbb Posted December 15, 2021 Share Posted December 15, 2021 I think wwe just hijacked the Den of Iniquity thread. 3 Quote Link to comment Share on other sites More sharing options...
Bridgehouse Posted December 15, 2021 Share Posted December 15, 2021 2 hours ago, Chienmortbb said: I think wwe just hijacked the Den of Iniquity thread. No, no. No no no. The DoI would insist that Pizza was invented well before trombones and thus the real question is “how many pieces of pizza can play the trombone?” 1 1 Quote Link to comment Share on other sites More sharing options...
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