Phil Starr

I've tried both the Behringer 205 and the TC VoiceSolo, they both work after a fashion. They are built to work on a mic stand but that is a bit of a nonsense as they make the stand too top heavy for anything but the most tame of gigs. They both are loud enough to cause feedback so extra volume isn't useful. The Behringer sounds like a very loud portable radio the TC is much cleaner sounding but as a practical proposition for vocals only the behringer works better as the mids are what you need and you will get early high frequency feedback from the TC IME. I sold my Behringer to my drummer so he could hear the vocalist and he liked it, with no vocal mic he could position it close and no feedback. For monitoring my backing vocals they are only OK if your drummer is loud. The gain you need to hear yourself over the drums is enough for anything that close to the mic to cause feedback issues. It's just good enough to pitch but that's it once you've cut it to stop it howling. (some say my bv's are howling) I lost them when I started using an RCF ART310 as a floor monitor. The much flatter response and the floor positioning allow all the gain you need. I'm losing my hearing, too much exposure to high levels of sound. Too late I'm turning to IEM's they don't just give you the sound they cut the sound level at your ears to levels that don't cause damage. Using earplugs is a matter of fit, I struggled with poor bass, falling out and tight uncomfortable plugs. All of these are cured by well fitting in-ears. I thought I'd feel cut off from the audience, you'll be amazed just how much audience sound comes through the vocal mics. On a good day I get hi-fi/studio sound through my in-ears and my playing has improved because I can hear everything. I wish I'd done this when I started gigging and if I could pay £20,000 to get my hearing bck to where it was 15 years ago I'd take your arm off. Do yourself a favour and try some nice comfortable over-ears in rehearsal where no-one cares what you look like. Once you get that set up how you like it you will want that at a gig. Even those little Behringers are going to damage your hearing.

Bad luck, it is horrible when that happens. Before you rush off and start spending it is worth spending an hour or two checking what actually went wrong. It could be something simple you'll spot if you work through logically and without all the pressure. I don't think you checked your speaker lead for example and I'm not clear if you tried just going straight from bass to amp. Speakons often have screw terminals that work loose over time so there are a lot of very simple things it could be. If it is indeed the amp then it could be repairable. I can't say I stay rational and organised in these situations even though I know a cool head can fix most things You'll want to take a backup at least until you are confident about your amp. I have a Warwick Gnome which sits in my bass case and I also carry a DI box to gigs. Sansamp, Zoom B1four, there are loads of options.

God is there more than one or does he commute round the country

You've heard me play then 🤣

The Jack is an unusual design and has been optimised to work with specific speakers. To be honest I'd expect Bill's advice to be the best advice you can get if you want to build one of his designs.

I've not used either of your suggestions but by all accounts the PJB has a great all round sound. It may well have a flatter response in the bottom octave than an 8 but at the expense of efficiency and ultimately volume. I'm using a different system for this purpose. A Warwick Gnome (TC BAM or an Elf would work as well) with a 6" speaker. It's tuned to give a very respectable volume and a flat response down to 80Hz (there is very little actual bass 40-80Hz coming out of a bass pickup) It has a very satisfying sound, light agile and detailed, which is great for practice as the detail is what you need to hear nd the lack of subsonics reduces the noise carried through floors and walls. If you are handy with wood all you need to know is here House Jam Micro Cab - Amps and Cabs - Basschat https://www.basschat.co.uk/topic/455858-house-jam-micro-cab/

@Happy Jack has pretty much nailed it. I used to run a jam session. You should understand that most Jam Sessions aren't really a free for all. there is usually a core of people who form a house band with vaguely rotating members. The organiser is usually being paid a few quid by the pub and so they have to make sure the music keeps on going and are at least not driving the other customers out of the pub. I had a couple of singers who would usually give me advance warning of what they wanted to sing and I'd have chord sheets available for some of the songs. Most popular songs have three or four chords and simple structures and anyone who has played in covers bands will have a few songs in common. Any 'jamming' is usually a guitar solo played over a single chord or either a verse or chorus repeated for far longer than is sensible I had a lot of bands come along and play half a dozen songs if they are 'between' gigs and a couple of acoustic acts who would just do their thing but borrow bass and drums. As for playing bass at these things, I'm the worlds worst improvisor and played some shocking mistakes. No-one seemed to notice, too busy dreaming up their own mistakes I guess. I prepared as best I could, made a note of songs I hadn't heard before and looked up the chord sequences. Keep the playing simple, root note only or root fifth. The most I would do would be simple 3 note arpeggios but the root is your friend. Oh and don't forget you can use dead notes when you haven't a clue what the guitars are doing. I loved it when the guitars were playing full chords for a song. If you recognise the chord you know what the root is, barred chords are easy to follow.

My bass practice has stalled and my tea has gone cold as I've disappeared down another rabbit hole I'm a biologist by training and chemistry was my second subject at university, I started to fact check and bamboo is way more interesting than I imagined, and my chemistry way more rusty than I realised. So to summarise bamboo has a very different structure to wood. It is made of similar cells arranged in a different way. The conducting tissues are surrounded by bundles of fibre cells which give the stems their stiffness. These cells are longer than most similar cells in woody tissue. There are lots of these fibre/conducting bundles in the stems and they are surrounded by parenchyma cells, these are softer cells and they strengthen the structure by absorbing and spreading forces on the fibres. Mechanically this is very like fibreglass. It goes beyond this. The fibre cells have walls which are made of strands called fibrils, as are all woody tissues, but bamboo has evolved a few extra tricks. The ratio of lignin to hemicellulose in the fibrils shows higher levels of hemicelluloses which are less strong than lignin but the mixture is stronger than lignin alone as the hemicelluloses create strong hydrogen bonds with the lignin. The hemicelluloses also have microfibrils which increase the strength of the fibres. Article in Nature Bamboo is a grass, not wood and it has lots of exciting possibilities. It grows quickly, maturity in 4-5 years and not decades like wood. The plant survives harvesting. The 'waste' can be chemically treated (breaking those hydrogen bonds) to produce long soft fibres softer and stronger than cotton. The technology is young and developing so the price may drop as it is scaled up. Whether monocultures of bamboo prove to be better than monocultures of cotton and spruce/fir is a potential issue but bamboo is more productive and may be able to address the shortage of timber in the construction industry. Certainly growing a fibreglass like material as strong as steel sounds promising. For bass cabs the Youngs modulus/stiffness thing could mean thinner cab walls and lighter cabs. I don't know how easy it will be to cut/drill/glue/shape. The density isn't an issue, it's lighter than some hardwood ply not as light as poplar. I think at this time it's wait and see. Will availability improve and the price come down? It's great we have one entrant into the bamboo cab market. If it is successful we'll see more.

This sounds right to me too. Early on Tommy was experimenting with a range of drivers and sold off a few of his trialled drivers here. I tried to buy some of them. I got the impression at the time he had settled on eminence.

It will. The Kappalite has a more powerful magnet system and this damps the movement of the speaker more than the less powerful motor system in the Deltalite. This means it works better in a smaller cabinet. The kappalite is the speaker to beat for a tweeterless 115 for me and something I was considering for a Basschat design, and my own use. It's the basis for the original barefaced cab and a great choice used by a lot of other people. Not only does it have an excellent bass response but a wide flat upper mid peak that will sound quite musical. If you are serious about a build then why not start another thread and we can maybe do something there. Hopefully you can put up some pics of the build and encourage others to have a go at a self build Best to tag me on that thread as I've got a new band and don't come on quite as often as when I'm with an established band or between bands.

We seem to have wandered off a bit from Al's first post but it is great to have a place to discuss PA Just something to think about really when discussing putting the PA at the back behind the players. It just isn't a great idea really. I'm a pragmatic person so I'm not saying it can never work, I will say it is never the best solution in terms of how your band will sound. Two reasons for this. The PA is louder than the human voice. If it isn't why would you use it, just sing. If you have anything other than an acoustic band the band is likely to be louder than the vocals and even though the mic is much closer to the singer than the rest of the band it will pick up everything in it's line of fire. I have meters on all channels and those vocal mics are busy all the time even when the singer isn't there. A hit on the snare registers at the same volume as the singers voice. You need to get a clean sound from each musician to get a good mix so moving anything away from the vocal mics is good. Don't put the PA at the back, keep it in front where as little sound as possible leaks into the vocal mics. Point everything back line away from the mics if possible. I've mixed for bands that are so loud on stage that there is no point in the set where the singers voice matches the instruments in the vocal mic. Secondly there's a thing called 'gain before feedback' link. It's basically very simple, how loud can you turn things up before feedback. There's loads of components to this from the acoustics of the room, pickup pattern of the mic, how flat the frequency response of your system is, how loud the rest of the sound is and so on. It's quite possible that with a singer with a loud voice you can turn down the gain and they can go into the audience. Or turn down the gain and just be quieter. Or just be in a perfect room with no little acoustic problems but eventually if you turn up loud enough your PA starts screaming. A column may well have a flatter response than a poorly designed horn and a more predictable dispersion but that's as much about the quality of the system. A good horn system will beat a poorly executed column. Putting the speaker at the back was a bit of advertising from Bose written by the marketing people. Putting anything behind the vocal mics just decreases the gain before feedback over placing them in front. Something you can possibly get away with but never a good idea.

I've a 115 design at home with an Eminence Deltalite as the driver, I think I can do better with the choice of driver but if you are happy with building a one off at any stage I'm happy to share what is work in progress. i've a 1x15 design

Yes I used WinISD for the calculations/modelling. The results are around what I expected but the program makes a number of assumptions about the design which can put the tuning out a little. When we do this as a 'proper' BassChat design we also check the T/S parameters by directly measuring them. So far the Faitals have proven to be pretty much on spec but that isn't always true of every speaker.

OK we have a design, c100litres with a slot port at the base of the cab. Using two Faital 320's 83cm H, 51cm W and 36cm D. The port is 6cm high and 19cm long. i've tuned it to reduce the bass hump to just 1db and managed to extend the bass so -10db is 41hz. Coincidentally that is bottom E. Internally the dimensions are 80x48x30cm. Sensitivity is 98db/w and it should achieve a slightly scary 126db in real money.

It's so hard to be certain of the lifetime environmental cost of any timber products. US and European standards are pretty good and reasonably well controlled, though conservatives both sides of the Atlantic have cut back funding for inspection and enforcement agencies. Italian Poplar is to be trusted I think but for us over here it is more complex. Most of our 'Baltic' birch is Russian and only the outer plies are birch. A lot of 'Poplar' is made in China and is cored with either Populus yunnanensis or Eucalyptus deglupta and faced with Eucalyptus grandis or other hardwoods that may be sourced from elsewhere in South Asia. If you are a manufacturer buying in bulk it's reasonably easy to track back your timber but it's harder if you are buying a single sheet from the local hardware store. Bamboo looks to be a fantastic resource as it grows to maturity in 4 years or so and can be continuously harvested as the roots remain, a bit like the old coppicing system with hazel and chestnut, or more accurately like mowing very long grass. It will be interesting to see what they do with the waste (about 70%) what inputs are needed to maintain the growth and what problems large monocultures bring. I'm not cynical about this and almost any product made by photosynthesis has to be better than mining or manufacturing. I'm with you in recognising that FSC certified timber is already a 'green' material. I'm sceptical that some of the green hype over bamboo might be a little overdone. The devil is in the detail.

It's an interesting proposition. £100 a cab is expensive but for something high quality not completely prohibitive. Poplar worries me because it is soft and not too rigid so a harder material would be attractive. What I don't know about is workability and how it takes glue and finishes. You would still need some bracing and that tends to have a small glued surface so that might be an issue. If I do it there are people selling smaller panels on Ebay and I'd want to work with that first. I've also picked up a bamboo chopping board from Lidl. I'm going to make a cutlery drawer out of so it will be interesting to see how easy it is to work with

Interesting, so there are quite a range of differing bamboo laminates available. I haven't been able to discover the actual resin they use to bond the material but it is described as D3 which makes it shower proof but not fully waterproof and suggests it might be a PVA. In any case there is no problem with the release of formaldehydes when the boards are cut and shaped. The density is 0.7 (where water is 1) that compares with many plywoods but is heavier than poplar ply. It is very rigid though so you should be able to get away with thinner boards. It is also much harder than most woods so should handle knocks much better. the downside is that it is much more expensive than most plies, An 8'x4' sheet of 12mm board is around £200, enough for two decent sized cabs.

I need to get on and do some research. The fibres are used in some speaker cones but I’ve no idea how the bamboo is formed into sheets, they are really stable though even when wet..

It's potentially a great material, rigid and light. I've been eying up some of the bamboo laminates for a while as a potential cab material. Just need to find it as a sheet material, making a cab from Lidl's chopping boards has even been under consideration as a proof of concept.

It'll be a slot port as requested on the bottom of the cab. I don't like narrow slots so the barefaced vertical port is not ideal IMO, even if it looks aesthetic. That makes this a tall cab and with the 19" top it more or less designs itself. I only need to find an hour or so to fiddle with volumes and tunings and the design work is essentially done.

That's great, it means your cab is almost designed. the original Basschat Mk1 1x12 was designed for a 19" amp so basically you'll be getting two of those. If I remember it weighed about 11kg with ceramic speaker magnets. Yours should come in well under 20kg with the bigger cab but lighter drivers.

Last graph for a while This one shows the Faital 320 in three different sized boxes. The pink is the 50l box, red is 85l and green is 35l. This time the boxes are tweaked to get the 'best' out of each box. What you see happening will be true of any speaker put in different box sizes in general terms. The larger box allows the best bass response in that it is flatter and goes down lower. 85l is about perfect for this speaker in that respect. -3db is well below 50 Hz and -10db which is what most manufacturers quote is pretty close to the fundamental of bottom B on a fiver. Putting any speaker in a smaller cab introduces the bass hump and the smaller the cab the higher the frequency at which it happens. It doesn't show well in this graph but the peak gets higher too. The thing is that for a bass cab more bass isn't really a universally good thing. Our ears don't pick up sub100Hz very well but mics do so the vocal mics will amplify this bass even though we can't really hear it and the PA will quickly start to struggle. (use the 80Hz filters guys) If you are stuck in the corner those bass frequencies will be boosted and you might well start to excite room resonances. In listening tests we carried out with bass players most bassists thought the pink response was 'bassiest' not the red one. Only about one in three recognised the extra deep lows of the red response. That is bass players, most of humanity gets bass information from the second harmonic in the signal 80-160Hz. So now the question. How big do you want the cab to be? Given the trade off. I can give you the Pink response in a 100litre 2x12 using this lightweight value for money driver. I can get an extended response in a smaller box by using a speaker with a bigger magnet. Or I can get the box size right down with the pink response with the right driver if I can find one. A 100l 2x12 isn't huge but it is substantial, a few years back it was around the norm but with cheap drivers and for me a bit too much of a warm sounding hump. If you leave me to it I'll design around the Faital 12PR320 and try and optimise size and response but I think physics will push me to an 80-100l cab. If you want something smaller I'll look for another driver, though the perfect driver can be hard to find.

Outed

OK I've managed to grab a few minutes and I'm looking at the Faital 320 as the speaker to beat. So I'm looking at tuning first I can shape the response by tuning the port to differing frequencies, in this case gold is tuned to 45Hz and the purple to 55Hz. Tuning higher gives the raised hump at 90Hz and the lower tuning gives an almost flat response. For me a 3dB hump is just too warm and woolly 1db is just noticeable so 2dB is kind of where I'd like it to sit. But, it isn't just the response that is affected. The software is adding the output from the port and the speaker itself and when th port is active it is damping the movement of the speaker. That in turn affects power handling. So this graph shows the power handling. You can see the power handling is restored to the full 300W of the thermal limit where the ports are tuned at 45 and 55Hz in the different tunings. The dip above this is because the speaker excursion is beyond the limits the speaker can handle. What's going on here is the coil is moving outside the safety of the magnetic field. So at 70Hz the power handling is reduces to 120W at the lower tuning. I'm going to be looking at every aspect of the speakers behaviour even though I'm going to be talking about bass response most of the time. I might come up with a recommendation that looks sub optimal but in the background I'll be trading off gains in one are against a cost somewhere else. Speaker design is a bit like squeezing a balloon. Solve one problem and another one pops up elsewhere

It was always our hope that these designs would last for many years so it is great that you are building this we hope that it will stimulate others to do the same.