Phil Starr

Thanks Geoff, I have visitors this w/e. I'll have a look on Mon.

I can do a rough calculation based on that but I need the exact width and height of the port as well as the length to get it right. Check for anything loose whist you are looking

[quote name='geoffbyrne' timestamp='1496255984' post='3310022'] If I pluck a low B and let it ring, I hear it 'fluttering'. The original driver was farting out badly at any decent volume (EQ flat) so I thought I'd try a Beyma in it. Big improvement but, as I said, there's still this 'flutter' that to my uneducated ear sounds like the air pushing & pulling through the ports. (Chuffing?) I was wondering if an exta round port at the back would improve matters? What measurements do you need, Phil? G. [/quote] I want to calculate the tuning frequency of the cab, I have the dimensions of the cab from Ashdown's ads but I need to know how long the port is. It could be chuffing or it could be something loose in the cab. It's very hard to be certain without hearing the cab. It might be worth a quick look to check if any stuffing in the cab is loose or there is anything moving around near the port, like the cabinet covering. It's an outside chance but worth a check. The Beyma will probably shift more air than the original driver so chuffing is certainly a possibility. You can't just add a port, that will completely change the tuning of the cab. You'd need to considerably modify the cab if you need a bigger port, possible but it might be easier to build a new cab, and cheaper if you sell on the Ashdown which will lose most of it's value if no longer original. Low B at full power is always going to be a challenge for a single 12" speaker but let me have the depth of the port and i'll have a think.

[quote name='Bill Fitzmaurice' timestamp='1496144686' post='3309067'] I don't know about Linden, but American Basswood is too lightweight for speaker cabinets. It's considered a junk wood, not suitable for construction or furniture. It doesn't even burn well. [/quote] It's just not something we see over here as a plywood so I've no experience of it. My son lives in Japan and when we visit I grab the chance to look at Japanese joinery. I don't recognise many of the timbers and like everything in Japan they try to use Japanese materials. The ply I've seen is fantastically good quality but was being used for finish work so you'd expect that. DIYJapan you need to just chat with your timber merchant about it's suitability, you don't get to do anything in Japan without a hell of a lot of training so they are likely to be knowledgeable about timber even if not speaker cabs.

[quote name='Thunderpaws' timestamp='1496179548' post='3309432'] Is it the volume of the port that matters? For example, if corner triangular prisms were used, should the volume of the prism be the same as the volume of the cylinder that makes a circular tube port? [/quote] Yeah, as Beer of the Bass says you need to calculate the ports for each cab and tuning but in a practical sense the length of the port depends upon it's cross sectional area so if the corner ports are the same area as the round ones their length will be the same. There's a slight complication because the termination of the port has a different impedance against the walls of the cab so there will be a small end correction to apply. In practice the cab would work OK but you probably wouldn't hit the tuning exactly.

[quote name='Count Bassy' timestamp='1496183854' post='3309468'] One thing (possibly the only thing) I remember from my Physics degree is that at the same pressure doubling the diameter of a pipe will increase the flow by a factor of 16, not the 4 times that the actual area might suggest. So, although 4 ports of diameter X will have have the same area as a single port of diameter 2X, the flow through the single large port would would 16 times that of a single port at X, or 4 times the flow of 4 ports of the same total area. [/quote] I have a distant memory of studying fluid dynamics 40 years ago and some 'interesting' maths. It should have been obvious but it's easy to get complacent when using computer models . I guess that narrow ports are more resistive and you get turbulence at lower port velocities.

Hi Geoff, I had a quick look at the Ashdown and I don't see why it wouldn't sound at least OK with the Beyma. It looks to be a similar sized cab to ours and I'm guessing tuned within the ranges we tried. If you could measure the depth of the port I could look at it properly for you. What exactly do you mean by "it isn't breathing smoothly at low frequencies"?

If you are doing covers I suspect it's about not knowing the song as much as being rhythm blind. There's a huge difference between being not being able to do something and never being able to do it. The difference is practice I don't think singing is as easy as it looks for most of us. I struggle to play bass and sing at the same time, especially when the chord changes don't line up with the sung line. Singers tend to be over confident, they can sing along with the original so they reckon they can do it to order. By now I'm imagining their confidence is shattered as it has been a topic of debate which probably doesn't help. With three weeks to go I'd be thinking of cancelling TBH, but you want practical suggestions. They have to listen to the songs over and over again at every available opportunity. Get another band member to cue them in either by counting them in or by playing a cue or even giving them a nod or a wink. Can they come in on time with a Karaoke track? If you can get backing tracks for your songs it gives them something solid to practice with. Sit down with them one to one and go through the problematic songs listening to the originals, pick out what the music does just before they come in . Get them to listen out for that cue and practice that entrance only. 3 weeks isn't much time, all any of you can do at this stage is to try your best (who booked in a gig before you were ready?) once it is over your singist needs to decide if they want to spend the hours working on each song to bring them up to scratch. If not it might be time to move on.

Whilst I don't know about basswood as a material for ply I would imagine it would be OK, a whole variety of plywoods are available here and often the only part of the plywood that is the named species are the face plies. One supplier over here offers a generic 'hardwood' ply which I prefer to birch ply anyway. Given the quality of Japan's carpentry and the use of a lot of indigenous semi-tropical timbers I wouldn't be surprised if it is very decent quality. We designed the cabs so you could build two out of an eight by four sheet so 18sq ft should be plenty.

surprised no-one has mentioned the biggest difference between the Gibson and the Epi's. Gibsons are really light basses. The Epi's are beasts. I have to say mine created quite a stir at every gig I took it to, just the look of it really, and I loved the sound it made, the sustain and the super fast narrow neck. In the end the neck dive and the twist spoiled it for me. I watched Martin Turner (Wishbone Ash https://www.youtube.com/watch?v=mUolWNHxRiM ) last Friday and like most of the T-bird players he plays mainly with a pick and the bass on his thigh with his picking arm resting against the bass. I play finger style only and without that restraining arm they dive like crazy. I sold the Gibson, it was a waste to have a lovely bass unplayed, then I missed it and a Japanese T-bird came up, a Burny by Fernandes. It has the same light weight and fast neck, the sound is great but without that snarl the Gibson has when you dig in. If the OP is thinking about a purchase try the Epi and Gibson next to each other, it's a completely different experience. Personally I'd wait and see what Epiphone bring out next if a new model is due soon.

[quote name='geoffbyrne' timestamp='1495907223' post='3307512'] Hope not to derail..... I have a Beyma 212 - but am totally hopeless with tools. Anyone building these cabs for money? G. [/quote] It isn't too difficult to build these if you get the panels cut to size for you. If you can use a screwdriver the Mk1 pretty much assembles itself. B&Q will usually cut the panels and a smaller timber merchant will usually help. Some might even offer to cut the holes in the baffle for you.

You'll find designing cabs is a bit like wrestling a balloon. You force one problem into place and something pops out somewhere else. We've very much found that to be the case with designing the Basschat 12. The main thing I was trying to achieve in the Mk1 was a decent speaker that would be easy to build. If you follow the original thread you'll see I built both a tube ported box and one with a wooden slot port. I plumped for the tube ports because of the simplicity of the build and the ready availability in Europe of black downpipe of the right diameter. We ended up with four to keep the port noises down. The slot port version had a resonance when I dropped it, I couldn't leave it alone though and when I went back found it was down to a reflection off the port itself. I damped it down with some judicious stuffing and it could have been designed out with a taller narrower cab. Having built both I thought the tube port tube design was easier to make for someone with limited tools and woodworking experience. Since then working on the Mk2 we've found that a single port gives a lot less port noise than a group of four with the same cross sectional area. I'm not keen on four corner ports for that reason, but it does help stiffen the cab. Balloon wrestling again. My conclusion? I wouldn't worry too much about the ports. If you are a confident woodworker forming them out of wooden slots is fine. The four ports in the Mk1 have never made any audible noises at a gig, even when pushed hard, most/many manufacturers of bass cabs make slot ported designs and there are successful designs out there with corner ports.

The 3012HO is a bit wasted in a box that size. 35-40l is probably better. It will work in the Basschat 12 and you can change the shape to make it taller so long as you stick with the overall volume and the port dimensions. You could use the dimensions of the Mk 2 if you want and leave out the horn, Stevie spent some time working on the bracing and you could simply copy his. The Eminence Beta 12A-2 will work well in this cab. I can imagine getting hold of the Beyma we used would be nigh on impossible in Japan. My son works in Tokyo If you want help with the design just keep posting questions here.

[quote name='LewisK1975' timestamp='1495806826' post='3306773'] Interesting - I bought myself an AKG D5 and was ribbed by my bandmates for not buying an SM58. [/quote]The last laugh is yours I think. I inadvertently did an A to B test of these two when mixing for a friend. Her SM58 cut out and I swapped mid song with my AKG. The clarity and amount of detail that suddenly appeared was stunning. Not surprising really, the SM58 dates back to 1962 it was great in its time and has been a really reliable performer. Technology and materials science has moved on since then and Shure only make the SM58 because people won't let go. The Beta 58 is their modern offering and is way better than the old SM.

Hi Steve, yes mainly the D5's, feedback rejection is pretty good with them anyway. See you are down at the Marine tonight, I might make it down there if I can escape.

[quote name='Steve Browning' timestamp='1495788741' post='3306540'] Our side fills are Alto TX10s and they do the job perfectly. The drummer's one is, indeed, on a short speaker stand so he and I can hear the vocals etc. Works brilliantly. [/quote] Thanks Steve it's encouraging me to give it a go. Do you get any feedback problems?

[quote name='AdamWoodBass' timestamp='1495783767' post='3306485'] Only time I've used side fills is many years ago in an originals rock band. The frontman ran a really high end PA hire company so we were able to get on the bill for a lot of festivals and outdoor gigs. I'd say they are very useful because they fill the stage and you really get a sense of atmosphere to the gig, we also had wedges at the front but that was pretty much just for vocals. For the band it feels very natural and seems to add a little something to the gig. For the guy doing the front of house mix it's a nightmare from what I understand because they have to ensure the side fills don't bleed into the mix for the FoH system. Typically it's really useful outdoors where accoustics of a room aren't a factor but in a theater or something it can be a pain. [/quote] I grew up with the idea of sidefills bleeding into mic's being a problem, but that was in the days of SM58 mics and earlier. The dead spot for those cardioids is looking along the mic straight at the monitor. The AKG's and Sennheisers I use now are super cardioids where the dead spot is offset at about 135 degrees but they are pretty dead from the sides. I've a little personal vocal monitor for just my vocals and it works much better from the side than looking down the barrel. Much less feedback and somehow easier to pick out your voice when it comes from that direction. That's all got me thinking. Good to hear what you say about atmosphere too.

We play in a lot of cramped spaces in pubs with limited floor space and often poor acoustics. Band politics and funds won't allow in ears. We've also had a series of incidents where punters trip over floor monitors and catapult themselves into the band. Most of our mics are supercardioid rather than cardioid so monitors need to be to one side rather than straight ahead, so I'm thinking that a couple of small PA speakers at ear height would take up less space and potentially be clearer than our current line of floor monitors. Has anyone tried this?

Looks like you tried all the right things. If it's all been working OK through the Aux out then it's unlikely to be the speaker end so you are left with the mixer. Could be a connection problem or I suppose a software glitch. You did switch it off and on again! I don't know the Soundcraft, is it possible there's some way of muting the output?

In most cases 24dB/octave is going to be much better if what you want to do is clean out the crap without affecting your sound. Happy to give you the technical reasons if you want.

The most likely explanation is the leads, though it could be a socket. If there is a poor joint or an invisible break in the cable itself then just wiggling something can re-make the connection. If you've connected it up at home you'll have done a lot of wiggling and maybe swapped leads around. Intermittent faults are a bugger to find. Always carry some masking tape with you to gigs and you can mark the leads in any channel that fails, then you can investigate when you get home. There's also nothing to lose by squirting some switch cleaner into the sockets. Sensibly you could replace all the leads and eliminate them as suspects. Good luck

[quote name='Bill Fitzmaurice' timestamp='1495641564' post='3305548'] My living room is larger than that. Maybe I should start charging my guests for their drinks? I can't imagine a room that small being able to pay me enough to leave the house. As for subs, read what I actually posted. Low tend to make their way throughout the room no matter what its size. It's the directional mids and highs that need spreading about. [/quote]It's a cultural thing Bill, a lot of our pubs are in very old buildings, often converted domestic houses completely unsuitable for live music, but we go ahead anyway. It's more common for drums being too loud than needing any extra help, hence the pragmatic approach. Ideal isn't available to us so we do what works. My local dates back to the 14th century.

The 70's was considered the low point of Fenders by many, the CBS era, funny how things change. https://reverb.com/uk/news/fender-and-the-cbs-takeover I wonder if there are other reasons for the sound difference. The pups will vary, modern pups tend to be higher impedance/over-wound. That will limit the mids. Magnets do fade over time too depending upon the material so that could be a factor. I note some high end guitar manufacturers are baking woods to speed up the chemical cross linking of the wood fibres, old wood will do that naturally, and of course wood is bought in batches from all round the world as timber resources are depleted. Older slow grown and exotic timbers are just getting harder to find as species and habitats are destroyed. You have the excuse to try lots of basses though, good luck with the quest.

Late to the party I'm afraid. My need was exactly the same as yours, to keep away from the lights on or off scenario. I started on the Parbar route, four lights with the controller built into the pole with a foot controller. I wouldn't recommend these particularly, the built in programs are for discos and just change too quickly for most bands, not great for your big ballad You can set them to static but who needs four identical lights. I also got complaints for band members that they are quite bright shining into their eyes the beams are quite narrow. They ended up on the floor so I went out and bought a 12 light strip (something like this https://www.lighthouseaudiovisual.co.uk/ledj-pixel-storm-12-tri-batten-led-bar-67054-p.asp?gclid=COSA9oKTiNQCFQu4GwodrqMDLw ). It sits behind the drummer and lights up the whole rear wall. It's 12x3W triclour led and it's enough for the places we play, good strong colours, crucially it only responds to bass in the sound to light mode so keeps time with the closest bass source, kick or bass. I'm going to add a couple of static led par lights to give the stage a colour wash and some light when the music stops. I like the idea of just three lights and I use the parbar to light the audience, they are really excellent for this. The drummer has a little laser light which creates little points of red and green that swirl around us. That works well for a bit of atmosphere. As to brands I don't think there is a whole lot of variation short of the genuinely pro stuff which'll cost more than your PA. It all looks like it comes out of the same factory in China. Look out for the larger leds and COB lights as people have said. The Harley Bensons were only cheaper than the Chauvet, ADJ and Kam lights when I checked because the came with lesser stands and check you are getting a decent metal housing if you want it all to stand regular use. Outside of the main disco brands there is some remarkably cheap stuff on eBay but I've fought shy of trying it. I decide not to go the DMX controller route, just too distracting to fiddle with when I'm supposed to be playing bass.

[quote name='Jus Lukin' timestamp='1495564374' post='3304913'] It's probably more a question of dispersion in any speaker system, and how much one actually needs​ to hear the full range of any signal for a gig to work. And also whether​ one brand can improve on dispersion over another, or whether dispersion is a fixed factor of, say a 12" driver, regardless. I'd love to have some kind if solid answer, but as in your OP, it's pretty hotly contested! [/quote] Actually this thread has been quite civilised. I'm quite keen to hear people's actual experiences about what problems they've had so I can get a feel of how much they need to hear the full range of signal. I'll stick my neck out and try to explain the technical side of things, I declined to have a bash at that on the other thread when it all got a bit heated. The techies amongst you will see where I've glossed over a bit of detail and I'll be as accurate as I can but it'll be simplified. All the classic experiments on dispersion have used a rigid transducer (posh word for speaker, but think more like a tiny horn driver) which acts as a piston. They did this with the 'speaker' mounted at the end of a long tube the same diameter as the speaker and repeated it in free air and with it mounted in a large flat plate. That was to show what effect a speaker cab would have (sort of). What you find is that as the frequency goes up the radiation of higher frequencies narrows once you go past the point where the width of the speaker becomes a significant fraction of the wavelength. What is happening is that from the front all of the sound from the speaker reaches your ears at just about the same time. From the side some of the sound from the other side of the speaker takes a little longer and this interferes with what you hear. (I'm happy to explain this cancellation process but let's keep it short) In practice what this means for a 12" speaker is that up to around 500Hz gives a fairly flat radiation response and even at 1000Hz there isn't going to be too much loss of high frequencies 30degrees off axis. (This will vary with the cab a little) above 2000Hz in a practical speaker cab the response begins to be lobed and an off axis response will show quite big irregularities in the frequency response. If you go to the Faital site you can see this for yourself with the regular bumps in a falling response off axis http://www.faitalpro.com/en/products/LF_Loudspeakers/product_details/datasheet.php?id=101050110 If you are as nerdy as me you can compare speakers ad they do this for all their drivers. You can see they all have the same rough pattern but there are differences between drivers. Of course this is all theory, in practice practical speaker cones are made of paper and have to be light or they wouldn't make much noise. This means they bend. A typical 12" speaker will have a 2" voice coil, a corrugated surround at the edge and the cone will weigh about 40g. At 2000Hz it has to move forward then backward then return to zero 2,000 times a second. That initial push from the centre takes a fraction of a second to travel through the paper so there will be a time lag before the edge moves and there will be resistance to the movement at the edge, and a limit to how fast that 40g can be accelerated and decelerated. So the cone starts to flex and effectively only the middle of the cone keeps moving in time with the signal. Martin Colloms describes the cone vibration as contracting to the driving point with increasing frequency and offers an equivalent circuit diagram which is how speaker designers mathematically model speaker behaviour. (Win ISD works on a model like this) If you are really into this stuff then I'd recommend High Performance Loudspeakers by Martin Colloms pub Wiley as a good read. (how sad am I ) Speaker manufacturers have exploited this for years with hard metal domes and little 'whizzer cones' stuck straight onto the voice coil; used to extend frequency response. Cone materials are used to vary and control the flexing (Mark Bass use banana fibres in their pulp mix for example) and the thickness of the cones across their width is finely controlled, along with tricks like flared cones, conical cones and ribbed cones. The problem is that if you stick with pistonic cones you'd need to crossover at 500Hz, then you'd need to crossover again at 5,000 Hz as that speaker ceases to be pistonic, if you want to make a full range speaker. The holy grail of cone design is to have something that is well behaved enough under cone breakup to take you to the halfway frequency point where you can have a 2 way speaker to cover the whole range. It's what the cones do around that point which make a 2 way speaker design great or not. (maybe I've over simplified there) So to summarise, all 12's (all speaker sizes really) follow the same pattern of radiation but there are thing we can do to make crucial modifications and they don't all have the same off axis response.