Phil Starr

oops

If you do decide to go ahead with the SM212 then there are a couple of threads about the cabs you can read

Do say I've seen both bands several times. Andy Powell used to play Honiton Motel just down the road from me as a warm up for his annual European tour, it would have been rude not to go. A mate of mine is a big Wishbone Ash fan and I've seen the Martin Turner version a couple of times too. Very different approaches Martin's band is a recreation of WA with Martin front and centre. Andy Turner who I think has never really stopped gigging is more of a band, they'll play their latest songs as well as Argus and whilst the old ones are recognisable there's a lot of improvisation too. Both are good bands, I have to say Andy Turner is a lovely guy and so is Bob Skeat his bassist.

Where are you based in the UK? If you are anywhere near the West Country you are welcome to try out the SM212. It is loud and it does do lots of nice clean bass, the good excursion means that the transfer magnitude (basic frequency response) is maintained at high power. The response is pretty flat over most of the frequencies you get from the bass. Subjectively it means that it seems to lack a bit of top end as most other bass speakers either have a a bit of extra output above 1000Hz or are used with a horn. I gig with a pair of these (no horns) They are just kind of effortlessly bassy, in small rooms they can sound muddy but great in larger venues. I've designed a smaller cab for them too (30litres) which reduces the deep bass and creates a 3dBish boost around 100Hz which solved the problem of overwhelming bass in smaller venues. If I do go out with one cab it's the smaller one I take. That B&C has a bit of a top end boost which I currently dial in with a bit of eq on the Beymas, They are neo's too which are much lighter and would also work well in a smaller cab. Choosing a cab size for all your speakers helps you narrow down the choice but remember each speaker will work better in a cab which matches it try experimenting with smaller cabs and changing the tuning for the B&C and you might find a better compromise. The output at 100Hz needs to be pushed upwards and you can afford to lose a little below 50Hz. a smaller cab will also reduce excursion and improve power handling where it currently dips.

Ha ha I shouldn't do this so early in the morning. That paragraph didn't read well did it? I meant to say that my preference is for a mild but smooth rise in output through the upper mids and reduced output below 50Hz so extra deep bass isn't what I look for. That's down to taste and the way I use my bass, I'm only interested in sounding good live. I use headphones at home so I'm not interested in a good sound away from the band. as such I wasn't attracted to the BP102's extra bass and wasn't worried about the apparently lower bass output of the 2010. That's personal opinion though, not science. the science tells you the frequency response to expect, experience tells you what that is likely to sound like but taste isn't something I'd offer an opinion on. I'm completely with Bill, try modelling some more 12's unless you are determined to go for something smaller. I'd probably not recommend the SM212 particularly unless you want a lot of clean bass. It has has a great Xmax for the price and goes quite low in a reasonable sized cab so lots of deep bass but when I first recommended it it was £65 at around £100 there are alternatives to look at. B&C, Faital and RCF all do great drivers at around the £100 mark and over in the UK they are cheaper than the equivalent US products, as long as we are in the EU that is If you are really only going to use that amp then this might be worth modelling http://www.bluearan.co.uk/index.php?id=BAC12CL64&browsemode=category

First of all great advice from BFM. you need to re-do this with the same size cab to make sense of the response below 200Hz 'ish as the cab is as important as the driver . Above that look at the published responses. Is it the neo magnet? yes and no, you are looking at very different drivers. The BP 102 is really designed as part of a multiple driver and probably sealed cab. it's got a heavier cone (mms) and a softer long throw suspension for deeper bass, though a sealed cab would raise this. all this lowers the efficiency, it is less loud than the other speakers which wouldn't matter in a multiple driver cab. The basslite has a more powerful magnet and that is what is affecting the bass response. The increased magnetic power increases it's efficiency but also the electromagnetic damping of the speaker which rolls off the bass response. It'll respond well to being in a smaller box than the BP102 as the damping will be coming from the magnet and won't need to come rom the cab. It's the extra magnetic power that matters not the material the magnet is made of. Which will you prefer? well you won't know unless you build them all but this is my preference. The BP102 has a 'smiley face response baked in, it'll sound like an Ampeg. that bass peak is because it's an underdamped speaker but in the box you have the peak of that bass boost is quite low. I personally don't like excessive response below 50Hz, sounds great in the bedroom but playing live it just creates mud for the whole band. Have a close look at the upper peak of the Celestion. the vertical scale is 10dB on the graph and for the Eminence it's 5dB, that's going to be a big peak and a nice aggressive sound if you like that. Celestion calculate Xmax differently to eminence by the way. Eminence would rate it higher so the Pulse would be less excursion limited than your graph shows. They all have that upper range peak though, the heavier cone of the BP102 may be contributing to a smoother breakup mode but it's probably more complex than that You might also think about efficiency. The Pulse is loudest and the BP102 the quietest by 2db up and down from the Basslite. you'll hear that 2db difference and definitely notice 4dB. 118db midrange efficiency is going to be a bit short in a band situation but you might get away with it in the rehearsal room. You won't with 114dB.

I agree context is all. Brown Sugar contains a few historical references, 'houseboy' and 'Tent Show' which indicate Jagger had more than a passing knowledge of slavery. the gist of the song is that Brown Sugar tastes so good; better than white sugar perhaps? In context today that would be describing black people by their sexuality, black men are bigger and black women sexier. We'd quite rightly be in trouble if we said that at work or anywhere in public nowadays. It's one of those things we would think 'oh no grandad is going to say something racist, oh there he's said it' FWIW I don't think he is a racist. I grew up in the same part of Kent/south London as he did a few years later and went to the Grammar School next to his. I doubt he knew any black people growing up and around the time he wrote this he was having affairs with a series of black women. I'm fairly confident he was just carried away with how sexy it all was and thought he was saying something positive about black women. Brown Sugar was a great song, still fills the floor and takes me back to my youth but those lyrics are embarrassing in a modern context. I couldn't play Brown Sugar now it was different in the 70's.

I'm a bit surprised no-one has really got to the point yet. These were different times but there are a lot of things we see differently now Gold Coast slave ship bound for cotton fields Sold in the market down in New Orleans Scarred old slaver knows he's doin' all right Hear him whip the women just around midnight So the song is basically a joyous song about raping black slave women. I'm not surprised she doesn't want to sing those lyrics.

The problem with raising the cab is that you would lose the reinforcement you get from the floor which acts a bit like a mirror for the lower frequencies. That's less of a problem if you have two cabs of course but you could put a cab on a post with a top hat in each cab or use a speaker stand if you really wanted to do it. Personally I'd go for the Stagg stand and avoid having to modify my cabs.

JJ are a Slovak firm that make valves. Long time since I had anything to do with valves but I seem to remember the old British kit tended to favour EL34's and US amps tended towards 6550's but it's a long time since the 70's

Yeah Stevie spent a lot of effort in firstly choosing a nice driver for the horn and then taking out some of the irregularities out of the frequency response. It was really noticeable when we did the comparisons with other speakers at the SW bass bash and we had a chance to listen properly late on. It would be really interesting to try them as PA speakers.

Just to back up what John has said the only real way to avoid this is to use an HPF. remove the frequencies you can't really hear anyway. If your speaker is tuned to 50 Hz then filtering below 40Hz at 24dB/octave makes sense. Eminence recommend this for a lot of their speaker designs, not because there is anything wrong with their speakers but because they know their stuff. the other thing I'd say would be don't slap the bass without using compression or a limiter. Not all amps produce much in the way of really low frequencies but it's possible to make an amp that goes all the way down. If you did then when you pushed the strings down it wouldn't make a note but the cone would follow that movement. If you slap the strings you are pushing them down as far as they go so that represents an extreme movement The initial movement is relatively slow compared with say the 80 cycles per second of the main component of low E so this represents something going on below the resonant frequency of you cab. It's possible that Funkle's amp is one with a relatively low cut off, most have a bit of HPF baked in. Combine that with slapping and inadvertently he's invented a new obstacle course for speakers

First of all thanks for the link, really interesting, probably worth a thread on it's own To answer your question it's very simple. As you reduce the frequency the speaker has to move further to produce the same volume. To make things louder the speaker moves further as you turn up the power. The HPF simply reduces the power below a certain frequency. It's the combination of high power and low frequency that creates the greatest excursion. (This is a little more complicated if you have a ported cab. At high frequencies the air in the port doesn't move so the cab is in a practical sense sealed. As the frequency approaches the port tuning frequency the plug of air in the port starts to vibrate. This creates a back pressure on the speaker and reduces it's movement until at the tuning frequency it isn't moving at all and all the sound is coming from the port. Below this frequency the back pressure falls away very quickly and the air in the cab exerts no pressure on the speaker and it is effectively flapping around in free air. Excursion will become extreme at very low frequencies even with just a few 10's of watts because of the inherent design of all ported cabs)

I'm not sure how this was all measured and there is no scale on the vertical axis but all I see here is a filter cutting in at around 25Hz plus a little bit of non linearity between 25 and 100Hz due to an underdamped circuit. I'm not sure I understand what you are saying about stages. If the vertical divisions are 10db then this looks to me (I've done no proper sums though) like a 4th order Chebyshev at around 25Hz. That's going to remove some subsonics but leave the audio signal almost untouched. People speak well of the Thumpinator so copying it is a good idea, saves a lot of experimentation. As a speaker designer however I can say you could get more protection for your speakers by filtering at a higher frequency and I believe it would also sound better if you did that. I can see the logic of following an established design though. I'll follow this project with interest.

If you are going to crossover at 30Hz I don't think you need to agonise over Chebyshev v's Butterworth. We can't really hear anything below 50Hz in normal circumstances. Depending upon the exact frequencies your sensitivity going to be 18-24dB below the rest of the sound the band are making, including the upper frequencies of your bass, Because of the positioning of the pups there's at least another 12dB attenuation of output of those frequencies from the bass. My experience is that anything below 50Hz can be cut without anyone noticing and I believe most recording studios do this as a matter of course. Most ported bass speakers are tuned around the 50Hz mark and few bass guitar drivers have resonant frequencies much below this Even a few Hz below resonance the excursion of a cone rises dramatically and the coil will spend a lot of time outside the magnetic field endangering the driver and distorting the signal, the whole point of an HPF. If you go on the Eminence website you'll see they recommend HPF for most of their compact instrument designs. 40Hz makes more sense to me and even then I doubt you'd hear a difference playing an actual bass rather than test tones other than the filter would mean less distortion as the coil would stay in the linear part of the magnetic field

I nearly said that the reason I worried about this is that I've had to stop gigging with my 2x10 until I sort the grilles. I'm still using those horrible round grilles that are widely available and the cone's are reaching them at certain frequencies. They aren't really designed for high Xmax speakers. If you are slapping with an amp with no HPF or limiting/compression it won't matter which string you hit, the initial hit will be below the speakers resonant frequency and excursion will get out of hand fairly quickly bad luck though and easily sorted.

First of all choose your cab on how it sounds above any other factor. I'm not a big fan of the Ashdown sound either. I really want to like them as they are a great company to do business with but I just prefer other stuff. The point is that it's all down to taste and it just isn't mine. Having said that I quite like their 1x12. I think state of play at the moment is that a 1x15 or a 2x10 will keep up with most bands but a 1x12 needs to be a really good one to cope, but don't get fixated on size or brand, just use your ears and try before you buy. The other thing to think about is impedance. If you are going to get a single driver and second speaker later then they will both need to be 8ohm speakers. together they will be 4 ohms which is still going to match your amp. If you start with a 4ohm speaker then adding a second is going to be difficult. Finally think about what you want to use your system for. If you are gigging pubs twice a week you are going to value portability over most other things. carrying a couple of 4x10's every night gets old very quickly. If you are spending a lot of time in a rehearsal room where you can store gear you can get a used 4x10 really cheaply and it will cope with any gig situation. The reason they are cheap is that no-one wants to carry them but if you want something cheap that sounds good …...

Fly screen mesh is a new idea, just a quick look shows they do fibreglass mesh in black and grey as well as aluminium mesh plus polyester https://www.flyscreen.com/mesh/standard-rolls-for-cladding-and-screening/

Good news story in the end, we all make mistakes, if you put them right then you are a company I want to deal with. I read this through because I'd recommended Hercules stands to a band member just a couple of days ago. I wonder if Fiat will send me a new car if I complain about their soft touch car handles disintegrating on my 15 year old Multipla?

I don't think there is a problem, the only bit that would touch would be the outside of the cone. That is nearer the fixed outside edge of the grille so a 10mm distortion of the grille in the centre might only be 3mm near the edge of the cone, that would be quite a big dent! My only worry was that someone reading Pete's account might think it a good idea to rest the grill directly upon the speaker mount.

I don't think you'll have a problem, Stevie will have specified the batten's you used to support the grille to keep it well clear I think they were 20mm that you used? The 17mm is the point where the voice coil comes right out of the magnetic field and I doubt you will reach that point in practice. the distortion wouldn't be very nice either. All I was worried about was that someone reading this would think the foam on the speaker was there as some sort of protection. It isn't. Folks, you need the grille well clear of the speaker. 15mm is probably minimum for a bass speaker and that doesn't allow for any bending or denting of the grille over time.

I think you'll find the foam is only 5mm or so thick, less than the movement of the cone Xmax is 7mm and Xdamage 17mm I think.

I think only you can judge this. One of my bands is a noisy acoustic band and I use floor monitors for us. There are three reasons to use IEM's in my opinion, roughly in order of importance: they protect your hearing you can hear everything better so you play better it keeps all the backline out of vocal mics and cleans up your sound Obviously if you volume levels are so low that your hearing isn't under stress and you can hear everything anyway then I personally would not worry about monitoring. The glory of acoustic music is that you can hear everything and you have the ability to organically work together, over-complicate things and you could lose something. We are just loud enough to need to hear the vocals through monitoring, most venues it is overkill but a few have tricky acoustics hence we take monitors. It also helps because we mix from on stage and we now hear what the audience hear. We also leave the backline at home and just use monitors. If you do go for in ears then you'll need everything miked up, If everything is already going through it's own feed to the PA that won't be a problem but if IEM's are working properly they block off outside sounds so all you hear is what you put in. The only way round that with IEM's would be to use an ambient mic, a dedicated mic positioned to pick up the sound the audience hear which should of course be a balanced sound. That can work well and if you feed it back to the desk you can mix it in with other things (vocals?) and give people their own monitor mix. It's all common sense really. Pretty obvious that if you don't have a mic on the fiddle player and then you put in noise blocking in-ears you won't hear the fiddle. Only you can judge if you can all hear enough so it doesn't limit your performance or what you would lose by longer hearing that acoustic sound.

Well done all the people who contributed to this project. I'm sure there is plenty more to come when funkle has gigged the cab and we get more impressions of how it is working in practice, plus of course more impressions once the rest of the kits get built. My hope is that this design will go on to be a classic self build classic like the Greenboy designs. I know a lot of basschatters have contributed to the design and development, I applaud them all. This has been a truly cooperative project but of course one person deserves particular thanks. Well done Stevie

Sorry I've just re read your first post, the t-nut is still in the cab. I've had this happen a few times, For anyone following this t-nuts always have a tendency to come out like this, even a fleck of paint on the nut or the screw will bind the thread slightly and the temptation is to press down on the Allen key or screwdriver to get more purchase and as soon as you press downwards the nut comes away. You should be able to re-engage the points of the nut with the wood by pulling the nut upwards back into the wood. try lifting the speaker or remove the horn and push your fingers in to lift it from underneath, it looks like it is close to the horn cutout fortunately. If you can get the nut to grip a little then unscrew the bolt carefully with no downward pressure which will push the t-nut back out. Even if you can only push the nut up a bit it might let you grab the head of the bolt and pull from above but be careful about that speaker cone. If you get the bolt out then you can remove the speaker. If the threads are undamaged so you can turn the bolt and nut by finger then re fixing the t-nut is simple. Get a big washer and put it on the bolt, thread it though the offending hole and put the t-nut on the bottom, without the speaker anywhere near. Tighten the bolt as tight as you can and it will pull the t-nut hard into the hole and it should be more secure. When you go back to fixing the speaker tighten all the bolts by hand first pulling gently upwards as you go so as not to dislodge the t-nuts. If you want to be doubly sure use the washer and bolt trick to pull all the t-nuts home before having another go with the speaker.