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Everything posted by Phil Starr
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Well done, I'd come to exactly the same conclusion 110l is just too big to be a mini-sub but 80l is still manageable size wise but gives you a potentially flat(-3db) response down to 50Hz which was my target. If you're using winisd then you need to start looking at the tuning frequency, I found 40hz gives the flattest response with the slowest roll off but have a look at the power handling which improves a lot in the 50-100Hz range if you tune to 50hz. That's also reflected in the maximum output graphs. Tuning to 50Hz does mean there is a 1db hump and 45Hz looks a great compromise tuning on just the frequency response but excursion limited power means that response won't be available when running at high levels. That could bring on reliability problems but is much more likely to introduce distortion. On that basis I'd go for a 50Hz tuning, it's probably going to make little difference in practice as you rarely get to full power levels and the speaker still has a bit of safety margin beyond xmax. There is very little fundamental in bass guitar so it is only drums that will be likely to demand those high levels of output. Frankly I would always put a limiter/compression on drum mics anyway. I also don't think you'd notice the 1db hump in practice. This is an area where the designers choice comes in but have a look before you start making sawdust and see what you think. The port calculations are simple in winisd, just change the shape of the port to square put the full width of the cab in as one of the dimensions and away you go. You need to look at 'rear port velocity'; that's just a winisd quirk, you can put the port anywhere but it is calculated as rear port. Try and get the port velocity at all frequencies down to 50Hz below 17m/sec. Above this speed you'll get probable wind noise from the port. You need a larger port for a PA sub than a bass speaker as you are going to assume it will have to handle full bass output down to the design lowest frequency. As I've said you can get away with smaller ports for bass guitar which doesn't have a lot of fundamental. I found a 35cmx7cm port achieved this. Lastly shape; it's worth making the cab quite squat. the cab is likely to be supporting the tops so a bigger footprint makes for a more stable base. it also allows for a longer port which you'll need to avoid wind noise. Getting the speaker close to the ground will also give you reinforcement up to higher frequencies. With an instrument speaker a taller cab is better as it can improve the amount of mids reaching your ears when you are close to the cab on-stage. Good luck, you are pretty much there with the design. The bad news is that you now share my addiction to speakers
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OK this has uploaded. These are the responses of the SM212 in three cabs. The blue is 30l, green is the 50l BassChat Mk1 design and the red is a maximally flat design of 110l. You can clearly see the smaller the cab the less bass, though the blue30l cab is actually louder than the others at 120Hz the loss of thee bottom octave 40-80Hz is obvious. So now it is over to you to decide what you want. You can't really hear the frequencies below 50Hz very well and in small enclosed spaces they just make everything sound muddy by exciting room resonances. Most important to hearing bass well are the harmonics with 80-160Hz giving us the impression of bass which is why you think you can hear bass from a small radio speaker. It is perfectly possible to use the 50l cab here as a sub in a deliberately limited system. With a slight tweak of the tuning it will go down to 50Hz(-3db) and give you a slight boost at 100hz. Output will be 122db max which equated to what most manufacturers are describing as 128db. Obviously you'll be missing about half an octave of deep bass but that's going to affect any keyboards or kick/floor tom more than bass guitar where you'll hardly notice it. In a small venue you'd probably want to filter those frequencies out anyway. However the possibility is there to exploit a bit more of the SM212's potential by increasing the cab volume and getting a response between the 50 and 110l cab. Keeping the profile of the cab and increasing the depth by 20cm will give you a significant improvement in deep bass response.
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First of all the cab is correctly rated. It should be fine with your amp. if all else is well. Secondly unless the speaker cab is shorting out it is unlikely that the cab ort he speaker lead (which you might want to check) is responsible. The amp should turn itself off if there were anything wrong without causing problems other than temporary silence. There shouldn't be a smell of burning which is more likely to be an indicator of a failed or failing component inside the amp. if the amp is now working then all that has happened is that the protection circuits have taken over and switched the amp off for you, removing the power and letting the amp cool down has allowed it to re-set. It may be something as simple as a faulty joint sparking but something is wrong and I'd get somebody competent to have a look. Good Luck
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From a technical point of view it is no longer sensible to try and fill the room from backline amplification. To reach levels of 90db at the back of even a modest sized room you are going to have levels of well over 100db on stage. That is going to make it impossible to keep the sound out of the vocal mic(s) and you will always sound muddy. More importantly those levels will permanently damage your hearing after less than an hour and you will progressively lose more each time you gig. It makes much more sense to use modest sound levels on stage and use the PA in front of you to fill the room. In the long run it works out cheaper that way too and your equipment carrying will be easier on your backs. If this is a new venture it is worth having this conversation with the new band before you go down the 1970's route. If your drummer is unable to control their levels and your guitarist a bit of a dinosaur then I'd really strongly advise you to look to going in-ears. I now have huge hearing loss and tinnitus and I wish I had changed the approach earlier. Speakers like the Alto are fantastic value for money and way better than cheap speakers used to be, unbelievable for the price but there are compromises that have to be made at the price. Generally the problem with the bass drivers in the cabs is that they have smaller magnet systems and so excursion is limited and the frequency response is compromised. I use QSC and RCF speakers and currently you can get better sound at the price from the RCF's but both are great speakers as are Yamahas. You get what you pay for at this price point but the choice is yours, the cheapest solution would be a second matching Alto. That should mean you can match the output of the drums. Whether you choose better speakers is your choice. I'm surprised by the idea that RCF's are unreliable, mine have been faultless and I don't know of anyone who has had any trouble with them. They are nicely made. Obviously any product produced in the thousands can have the odd problem but this is the first I've heard of with RCF's. If @Woodwindhas additional information I'd be interested to hear about it.
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Whilst it is true that neodymium isn't particularly rare it is still in short supply, some of the other rare earths are in even shorter supply and a few used in computer chips are becoming a problem. Although the chemistry of acid leaching used to extract them isn't particularly sophisticated it's a highly polluting process. The 'ores' used in refining REE's have very low proportions of RE's so a lot of mining has to be done and almost all of this becomes acid polluted waste. Fly ash from power stations actually has a better proportion of REE's and is a waste product from mining that is already taking place. The electrical sintering process breaks up the crystalline structures of the ash and releases more of the neodymium so the process is several times more efficient. Reducing the cost of production by 90% and the increase in availability is going to reduce the price of anything that uses neodymium and that means renewable energy production. The extraction technique can also be used on mined ores and the waste products of aluminium production which is good because fly ash is the by-product of coal fired power stations which we all hope are on the way out. All of this is still in development, in the USA mainly and will take years to become significant but for those of us watching the increased availability of REE's with reduced environmental costs has to be good news and lord knows we need some now.
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OK I know some of you think that neodymium is the devil's magnetic but really it's just a way of making more powerful magnets or the same magnets in a smaller lighter way. Until a few years ago lightweight speakers were falling in price and becoming more and more common then the Chinese who produced most of the neodymium started an evil plan to build windmills and electric cars and cornered the market for the neo they were in fairness producing. Other countries have now opened their own mines and the neo availability has eased but neo speakers are still frighteningly expensive. A few years ago I bought a Deltalite for £66 it is now £200, almost as good as Bitcoin Now I picked up in New Scientist that a new technique for extracting Rare Earth Elements including neo from industrial waste has been developed which may have solved the speaker magnet problem. To be fair it may also save us from global warming through all those windmills and energy efficient motors but I digress. Basically the technique is to release all the REE's including neo by electrically sintering industrial waste from power stations and mining. The ash from power stations produced each year contains around 3.75 million tonnes of Rare Earths and the most recent figure I could find for REE consumption was 19,000tonnes in 2018. The new extraction process cuts the cost of extraction by 90% compared with conventional mining. So there you go, it's profitable, cuts our need to r*pe the planet with mines and potentially brings down the cost and availability problems of speaker magnets (and windmills) Rare earth metals are also used in the manufacture of electronics so expect even more of the devil's amplification. It's no accident we call it class D. PS I read this so you don't have to Rare earth elements from waste https://www.science.org/doi/10.1126/sciadv.abm3132
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Looks like you might have to wait a bit, I've been trying to upload some stuff but it seems I've broken BassChat Temporary limit on attachment upload sizes - Site News - Basschat
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Not the Peavey Microbass which I started out with. They are fine in that they make a noise and are bulletproof but they just don't make a satisfying noise. Lot's of deep bass and knowing you can go loud if you want to is really fun and for a bassist still satisfying even now. He's going to play more and practice more if it sounds good. I'd probably go for a used combo from one of the 'known' brands. I sold a Hartke Kickback 10 a couple of months ago for £100 only £25 less than I'd paid for it 10 years earlier so £2.50 per year. It sounded really nice, wasn't too big and I even gigged with it a couple of times. Ashdown, Fender and the like all offer similar options and a named amp will sell on really easily compared with something less well known for bass.
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Ha ha I shouldn't mention ideas so easily, now I think I've accidentally committed to designing something to get the best out of a 212 as a sub. It's really tough to design a small sub and less than 50l is problematic. To get something with a small box to have a predictable response you need to compensate for the reduced air mass with a low Q/big magnet driver. That leads to problems with a shelving response as detailed above. You also have to look at the moving mass of the driver and compliance and the knock on effects of all of this affect Vas and so on. It's where the SM212 hit a sweet spot of great all round driver. I think a <50l sub is going to involve compromises. A high cut off point, gradual roll off or reduced efficiency, it might work better with a smaller drive unit for example if box size and portability is the crucial factor. At this point you are designing a system not just a sub. The original 50l SM212 design was created by Basschatters asking for as much low bass output as possible from a truly portable speaker but which would cover the full range of a bass without a tweeter. As such it's most of the way to being a sub design. Maybe we could start another thread if you want a teeny tiny sub design, it might be an interesting challenge. I'm using DSP now in developing designs, so much quicker and easier than building passive crossovers and as you say you can retro fit something passive if it becomes a go-to cab.
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Flapping / distortion from rig combinations
Phil Starr replied to bigjimmyc's topic in Amps and Cabs
Whilst it is almost impossible for us to know what is going wrong at a distance and without more details I think Bill has probably nailed your issue and you need to eliminate this first of all. Your Traynor is lower powered than the other amps, has no bass boost and intrinsic to it's design it a lot of the bass frequencies filtered out. (Forget it sounding louder and bassier for a moment) Your other amps can drive higher powers at lower frequencies into your speakers and that is the classic cause of speakers 'farting out'. Of course we can't hear it so there is a possibility it is something other than the speakers. The thing is to understand how your tone controls work. Your Orange for example boasts +/- 15db of bass control and 'flat' is probably at 12 o'clock, turning the control to 6db of boost will deliver four times the power to your poor speakers (and demand it of your amplifiers output stage. The passive controls in the Traynor can't boost the bass, they only adjust it relative to the mids and treble. Everything full up is the nearest to flat it will do. It's a system that worked for many years and it's kind of intuitive to use because it isn't unlike the way our brains perceive sound. What we hear as 'bassy' is where the bass part of the spectrum is louder relative to the upper ranges. Most of what we hear as bass is upper bass low mids anyway. The really deep speaker flapping frequencies we are nearly deaf to and the valve amp sidesteps this issue by leaving them out and giving the speaker an easy ride. Try using a bit/ a lot of bass cut on your solid state amps and then seeing if the speaker flapping goes away. If so then you are just pushing them too hard. To restore your tone you might need to trim your mids and tops and/or buy an HPF but at least you will know where the problem lies. Our analogue brains weren't really made for the digital world -
They are, just got back from rehearsal, saved the settings from our last gig and then just plugged in and good to go. Good to go every time and first time. Individual monitors and the only one I have to ever set is the drummer's (and mine when he logs in to mine by mistake) The psychology is interesting, give them ordinary over ear headphones and they aren't threatened, it's just like the studio which they've all tried before, then get them to try in-ears and it's just a natural progression.
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Nice to see the M18 getting a workout.
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DV247 still haven't replied to a request for a missing bit from my delivery. I'll try and see if they can sort it as a way of testing out their after sales, let's see if i get any response.
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Unable to resist a challenge. I can see what Beyma have done but from a bass players point of view they haven't done us many favours. Essentially this is a completely new speaker and is a bit more 'specialist' than the all rounder the SM212 was. Basically they have fitted a bigger magnet and a larger diameter voice coil. The coil is shorter in the 'new' speaker and the magnet gap bigger and that has reduced Xmax but the power handling, which is rated thermally because the bigger diameter coil can radiate more heat. However the SM212 can shift more air 453cm rather than 334cm (wshat happened to the mathematical notation) which means more of the power is available. This is both speakers in a 50l cab with the SM212 in blue. You can see the extra 50W power handling on the flat lines but around the port frequencies the SM212 is clearly a 'winner' You can how this affects the sound levels produced this is the maximum sound levels with 300W into both speakers. By using a bigger magnet the magnetic forces are greater in the WR12 Qts is much lower and BL is higher. This creates new gains for the new design but also some losses. The new speaker will operate happily in a smaller cab. for a classically flat response it only needs to be in a 30l cab. the SM212 needs a 100l cab. I've chosen to model them in a 50l cab to make a 'fair' comparison. All this extra magnetic force will damp the movement of the cone. As the cone moves the coil in a magnetic field it induces a current in the coil opposite to the current coming from the amp. The stronger the movement and the stronger the field the more this happens so low Qts speakers tend to roll off the bass. Lots of other things come into play but you can see this in the frequency response. Again I've modelled this in the same 50litre cab for comparison. the last graph I promise You can see that the SM212 in blue shows that the 50l cab is a bit small and the magenet a bit weaker so the bass is slightly underdamped and has a peak. For the new speaker the reverse is true and you get an over damped response and a slow roll off from 200Hz. The -3db point is 80 Hz and down to 50Hz the SM212 has more bass. This is reversed below 60hz and at 40hz you get 3db greater output from the new design. However that is at low power because of the higher maximum displacement shown in the second graph the actual maximum bass clearly favours the old SM212 So is the new speaker better? I would say that at the price (big magnets aren't cheap) I'd have gone for a longer coil and a lower Qts, though that has all sorts of knock on implications for the rest of the design. The old SM212 hit a real sweet spot offering still outstanding excursion, power handling, efficiency and other positive features. The new speaker is better suited to a smaller box, both speakers have well controlled cone break up in the higher frequencies but for me Beyma have missed the mark slightly and there are other options. At the price of the SM212 in the UK it was a great speaker.
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Good news for anyone who wants to use the Beyma SM212, Blue Aran have just had a delivery of 33 speakers. I'm not sure if this is the last 33 in Europe all now in the UK or if BA have persuaded Beyma to make a small run of speakers. Either way if you are thinking of building one of our Mk1 or Mk2 designs I would consider securing the drivers now, they may not be available later. I'll put up some links later and get back here if I get more information from Blue Aran. I've also been looking at a design for a small PA sub using this speaker, I can put that up if people are interested.
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My first gigging cab, already quite old but sounded great, I still don't think I've found a better sound. I didn't find it too difficult to move, castors on the flat and it was no heavier than one of the Peavey 1x15 BWBW cabs. Looks like yours has the BW's with the metal domes? They had a nice top end
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Are you going to use it as a single driver for bass guitar? It has a slightly bigger magnet and good efficiency. The frequency response has a slight lift at the top end which is likely to sound quite nice with bass, I'd expect it to sound a bit livelier than the SM212. On the downside the excursion isn't so great as the SM212. This speaker is middling rather than exceptional in that area. For a pub gig one of these would work pretty well but you might need a second for bigger gigs. At £65 the price at Blue Aran is good. The best replacement we've found is the Faital Pro 320. That's a lovely speaker and lightweight but it's a neo and much more expensive, but not much more than the other Beyma so maybe within your budget. You could also look at the Beyma 12CMV2 which i've actually tried in our cabs and sounds quite good too, it's just had a price hike though.
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It's always good to look but they are very different beasts. The giveaway is the power handling this one has a 4" voice coil and it's that bigger coil that increases the ability to dissipate heat. It has a much heavier cone which is also stiffer so it doesn't reproduce high frequencies. It is designed for bass frequencies only and for a very small cabinet. VAS is only 40l versus 150l for the SM212. Xmax is calculated differently for the two drivers and is actually almost the same, there are three methods commonly used for measuring Xmax and beyma has joined the rest of the manufacturers in moving from the least flattering to the most flattering measurement. It's a nice speaker but designed for deep bass only, Xdamage is huge. It'd make a compact sub for PA or possibly for duties in a multi-way PA speaker.
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The Big Fat South-West Bass Bash - Now Sunday 19th September 2021
Phil Starr replied to scrumpymike's topic in Events
Any upright players looking for a slot. I've a friend looking for someone to play with his rockabilly band Redfoot based around Taunton. I've seen them and they are the real deal, the ad is in the bassists wanted section https://www.basschat.co.uk/topic/460457-double-bass-player-for-rock-and-roll-wanted/ -
The matching of cab to speaker isn't rocket science and with software to do the calculations not time consuming. There are rally only two variables to get a cab that works (though plenty of nerdy tweaks to squeeze a bit more performance). If a cab has the right volume and tuning to match a speakers parameters then it's going to be OK. If they don't you'll probably be messing up the bass response and crucially they won't handle high power levels and you could end up blowing speakers. That's worse case and most drivers have similar characteristics so swaps are only sometimes catastrophic. If you go that route, of swapping drivers, pm me and I can tell you if you are headed for disaster or not. Here are the build threads , though you seem to have decided this is not for you
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As one of the people designing speakers on Bass Chat I'll do my best. You seem to have considered most of the options or they have been suggested to you. Lighter Cab Wheeled Cab/Sack Truck Some sort of self build or modification seems to be something you are prepared to contemplate, so is the self build bespoke solution your preferred option or just the means to an end. I always advise people that self build is rarely a money saving proposition in that sometimes it works out but usually the cost of the materials and the new speakers works out similar to the cost of a second hand cab. A second hand cab can always be sold for pretty much what you paid for it. If you radically alter a cab it is likely to dramatically reduce it's saleability/price. Having said that a self build is really good fun and you learn a lot. sometimes it's the only way of getting exactly what you want. I've got a Lidl sack truck. They are cheap lightweight and pack down small. adding castors is simple and you can buy handles that fit on the top rear edge of a cab for wheeling. For lightweight you could go down a size. A single 12 if it's a good one will match an old 2x10 in output and that saves the weight of a magnet and frame. the smaller cab saves weight too. Whatever speaker size you use a neo magnet speaker will save you a couple of kg's per speaker on average. You can save more by using lightweight materials to make the cab. Another back saving solution is to split the cab. An 18kg 2x10 will weigh 10kg per cab if you buy it as a pair of 1x10's. Something like a Barefaced 1x12 will almost certainly have enough output for you and has a lightweight cab with a neo speaker. Other brands are available If you want to build there are designs by @stevie and myslf on here that will perform as well and come in at similar weights. There's also a 1x10 design. Just swapping speakers around is slightly more complex. Speakers and cabs are carefully matched and not every speaker will work in every cab. We can advise you. Think about what you really want and come back here
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Yeah we use RCF ART310's as floor monitors. They go to incredible levels before feeding back (courtesy of a nice flat response) and vocals are done really well. Bass is good but a bit heavy because they are designed to be on poles. I used the 310's as floor monitors at a jam night I used to run where a few bands were silly loud. The 310's didn't blink. I'm not saying they are the final word in monitoring, they would't do for a really huge stage but for a gigging band I honestly don't think you need to spend more. I've also used them for bass both on the floor and on poles. On poles its as good a bass sound as I've ever had. Very like the sound I get at home through my £150 Sennheiser headphones. The one thing I ought to say though is that it sounds like you have a bit of a volume war going on, It might be better to shift to in-ears for your hearing's sake.
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As you probably know Stevie and I have been designing cabs for BassChat members to build and I've sent several built and half built cabs to various people either to complete the development or for review. I've also sold off a few of the prototypes. Honestly I've never had a problem and it's the small packages that seem more likely to get dropped. I've not been fussed about which carriers I use, whoever is cheapest on the day and I ted to go to one of the brokers like parcels2go. I pay a lot less than £25 including insurance. £12 is nearer the mark for me. I always use a drop off point rather than have to hang around at home waiting at someone else's convenience. I use the same technique of layer of bubble wrap and double skin of carboard box. The couriers usually have a 20 or 25kg limit and a maximum size but none of my speakers are over a metre. I think there is an advantage in the size of speakers, they tend to be on the floor in the vans and they get carried one at a time so drops are less likely. Frankly they are designed to be dropped by roadies/musicians /drummers so you shouldn't have a problem.
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If you want to fix this the only way is to work through this logically eliminating each possible cause. You've already swapped in pickups you know are working and had the same result so you now know the pups are working. Everyone is telling you it isn't the tome wood so forget that. You haven't reported checking the height so I'm assuming you haven't tried that yet? The simplest thing would be to compare the height the strings are above the pole pieces on your working Squier and your not so good Vintage. If they are similar then it's unlikely to be that but you should try moving the pups upwards anyway to see if that improves things. If that doesn't work it's probably a wiring issue or possibly a faulty component, something just wired up the wrong way or something short or open circuit.
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I don't know how universal this is but I get so hot whenever performing, just buckets of sweat and complete over-heating by the end of a set. I'm straight outside at the mid-way break even when it's freezing. I guess it's adrenaline. I'm still a black T-shirt person mainly because I don't have to think about it, other stuff if the band want it of course (I have a fetching all pink left from a breast cancer gig) basically though the rule is as little as possible. I'm only 70 though so I'll let you know when I grow up.