Phil Starr

Glad someone else has spotted the bassline in Slade's Merry Christmas, it's a guilty pleasure. There's kind of a halfway house to walking which is just playing the major triad or pentatonic (rock'n'roll/rockabilly) or the minor pentatonic (blues/rock) which is a bit simpler. I was struggling to 'get ' the walking bass until I read the trick is that the last note of the bar is in the key of the next chord not the preceding one, ie the bass walks up to the next chord just before the guitars change which is what gives it the feel of movement. Most walking basslines seem to use a fixed step up each time so for instance you use the major 7th to lead to the next chord each time. Crazy little thing called love- Queen

By the time you have bought two of these kits + a virtual earth mixing module + case+ knobs, sockets etc you aren't going to get away with much less than £30 for your 2 channel mono mixer. Built this way the Behringer would work and probably sound better though if you DIY'd you'd be a lot more knowledgeable. Other brands are also available, if you just want something cheap then http://www.bluearan.co.uk/index.php?id=EVNG105AA&browsemode=category is cheap as chips. Those other kits would cost a lot more and you'd get better quality and if you spend enough you eventually might get top quality a bit cheaper than buying ready made, depending upon how much you've learned in the mean time. Sadly the days when DIY was a cheaper option are just about gone.

I'd add my thanks to Alex, it opens another topic for debate, perhaps. It could be relevant however. My problem is that I've heard the changes in critical listening tests, and more than once. I fully accept Stevie's arguments about objectivity, I taught A level students about double blind testing and statistical significance for years. I know how easy it is to hear something that isn't there but for me the effect wasn't insignificant so I still feel there is something to explain. 20% changes in compliance don't do it, Though I might have a go at 20% changes with a wider range of speakers in winISD. It may be that what I heard were changes in higher frequencies than I thought, Alex is showing the possibility that the flexibility of the cone changes with temperature and time and 'breaking in' a speaker may be more about changes in the compliance of the cone than changes in the suspension. There's something here that I, for one, don't quite understand. I'm expecting someone can come up with something I've missed but solving the puzzle is interesting and may lead to some new understanding. It could be that none of us know. That possibility is why we get so cross with people who just contradict with no evidence. As Monty Python said argument isn't just contradiction.

I've run Behringer EP series for years without a hiccup EP1500 and EP2500 in my case. They are really heavy is the only downside. I went over to Peavey IPR1600 recently which has a built in crossover for a sub if you need it. These are so light and the sound is pretty indistinguishable from the Behringers and frankly from most other PA amps. Again they just do the job and give me no pause for thought whatsoever. Not often available second hand however. I'd recommend either. I think we are going to go over completely to switch mode power supplies in the next few years for power amps (the lightweight part of the lightweight amps) That means either you wait until you can afford the new amps or you rub your hands with glee as you pick up lots of heavyweight bargains as the rest of us upgrade perfectly serviceable amps in a belated attempt to save our backs.

It's pretty rare to get static shocks off a mic, so it is safer to assume that something else is wrong. If a venue tells you they get a lot of 'static' they have unsafe wiring, don't trust them or their wiring. PAT testing your gear makes a lot of sense but a surprising number of mains sockets are incorrectly wired or faulty in other ways. I'd completely back up using RCD's and socket testers but there is one other precaution worth taking and that is to run all your gear off a single socket (obviously this only works if you have less than 3kW of gear, which is your 13A worth) If your earth is floating then at least all the earths on the amps/instruments/mics are at the same potential and you shouldn't get a shock in this way.

Good luck, I hope you like the sound. It's a decent speaker and a good match for your cab. Let us know what you make of the sound, all the theory in the world isn't a match for actually trying something and since I can't try every speaker personally it's good to get feedback on the ones I haven't tried.

To be fair to Fane sensitivity depends upon how it is measured or calculated in the case of my 96.5dB figure. WinISD calculates the output based on the force generated between the magnet and coil and the load the cone and spring of the suspension. It assumes the cone is moving as a piston. In the real world it is only thin paper and flexes at high frequencies and so may well give 99dB under some conditions. If what you really want is another Jack then LawrenceH has one he doesn't want, I think he put the build diary up on this site so you could see how well or badly it was made, just a thought. Before I went ahead with this I think I'd want to try the jack with a 1x15 and your amp. You could even use a 15" PA speaker if you used your crossover as it wouldn't let anything through to the horn driver. I've got a 15" Peavey cab you'd be welcome to try the Jack with but you might not be in my part of Southern Blighty. You ought to be able to find someone who'll lend you a 15 for an afternoon though.

Just to double up with the safety advice. Unplug the amp, don't trust the switches. Beware the big power supply capacitors. they store charge for a long time after the amp is turned off and I can testify that a 4,000uF capacitor at 70V is considerably more shocking than a mains jolt. This is how to discharge them http://www.acmehowto.com/howto/appliance/refrigerator/check/capacitor.php Turning the amp off whilst it is still playing will show you when most of the power has gone as the amp will fade for a few seconds as the voltage falls. A volt meter across the capacitor terminals will confirm it is discharged. Normally they discharge naturally across the circuits they are connected to so it is unlikely much charge if any will remain after the time it takes to get the case off the cab but it is better to be safe so check.

Thanks Stevie, and thanks Alex for your data. Stevie I looked at your earlier data, where CMS changed by 21%. I then tried varying just CMS by 21% for a couple of drivers in winisd and guess what, predicted changes in bass response were less than 0.1dB at any frequency above f3 (that's the cut off frequency for any non-nerds still following). This pretty much supports your argument that we wouldn't hear these changes. Dickason is giving lower figures for the changes so obviously there would be less chance for the sound to be noticeably different. Alex, your data is really interesting, especially in terms of trusting measurements, I would guess humidity is another factor especially with an absorbent paper cone. Are you saying that breaking in a speaker could be more important for higher frequencies than for simple things like box alignment? I've repaired a lot of cabs over the years, one of the things I've noticed is that old speaker cones are lighter in colour and have a more matte surface than new cones even of the same model. If surrounds or dust caps come away they usually come away with fibres from the surface layer of paper attached. Clearly the bonding between the fibres that make up the cone are breaking down over time. Given that most of the higher frequencies we hear from a speaker are above the frequency where the cone starts to flex then I would expect the mid/highs to change over time changing the tonal balance in consequence.

Hi Stevie thanks for the data. you can see compliance and hence Vas and fs changing as you'd expect but there is also a difference between mms and Qes between the two drivers. Were these measurements of two speakers one 'broken in' and one not? I've got an unused and a used deltalite here which I ordered at the same time and I thought out of curiosity that if I had time I would compare the two when I get round to building their ultimate cabs. If the variation (in mms for example) is down to manufacturing spread then I might need a bigger sample. How did you measure the parameters in your sample? I share your frustration when anyone says 'believe me because I'm an expert', there's either evidence or there isn't. I don't expect people to have all they've read over the years to hand or to take all the measurements themselves but it should be possible to back up categorical statements with a bit of data or at least a reference or two. I still disagree with you, I think speakers do change over time (bit surprising if they didn't) and that I have heard those changes with at least some speakers, your data isn't incompatible with that interpretation but it certainly doesn't confirm my belief either. I look forward to seeing the stuff you have from Dickason and when I get time I'll have a play around with your figures. Looks like Santa needs to bring me a new Cookbook. Phil

The mounting hole for both speakers is 352mm. the flat edges are for fitting into a narrower cab. The volume difference between 350W and 500 is 1.5dB. 1dB is just noticeable so this is slightly more than that. More importantly the Fane is only going to have a sensitivity of 96.5dB/W according to WinISD (said I didn't trust the specs) and the jack will be higher once you reach the horn's pass band. It could be as much as 6db higher but you'll have to check that on the BFM website. You'll just have to fiddle with the volume controls on your amp to balance the two, they will be plenty loud enough. Lawrence I think you will be right about the phase problems at crossover, there's the horns length to worry about if nothing else and we've discussed the phase problems in the Jacks throat before, always a problem with horn designs. Most of these problems are in areas where the ear is less sensitive so they may be more of a theoretical problem than a practical one. There's also going to be problems with reflections off the floor creating extra comb filter effects. Mixing these two speakers is going to give an unpredictable result but so long as Fleabag realizes there are no guarantees and is happy to experiment then the worse that can happen is that he ends up with a working 1x15 with good deep bass and a neutral sound.

There's a bit of a thing running on BC about mixing drivers which I don't necessarily agree with. Using multiple drivers does give comb filter effects and this also affects the radiation pattern (direction the sound goes) There is also a tendency for the minor lumps and bumps in frequency response to counteract each other and smooth out the sound but if you like the sound then it's all good, Techies don't tend to like these because they are unpredictable effects and they distort the original sound. It's also hard if you do 'get' the Physics to give advice for which you have no data as you don't want to let anyone down. To be honest I have no idea what mixing these two speakers will sound like, I've looked at the Jacks design and the frequency response of the Fanes and I know what similar speakers sound like, that's all. I'll have a go based on that. The jacks horn raises their efficiency above the cutoff point of the horn emphasizing the frequencies above this point and introducing some irregularities. Your 15 won't be as loud as the Jacks above this point though you may feel [b]any [/b]extra bass to be worthwhile. This is a matter of taste, your taste. The 'sound' of the Jacks and your 1x15 couldn't be more different, the lively 'voiced' design of the jacks and the very neutral 15. you are at two ends of the design spectrum. having a stereo amp helps a lot, you can use your fx as a crossover and just use the fane to fill in 'missing' bass. This way or you can feed a full range signal to both and get some of the frequency smoothing effect I mentioned. Raising the Jacks to ear level on the 15 will help on stage, Lots of wood to shift though. You'll have 4 set ups to play with then, each speaker alone, together with xover and together without. The final thing is that if you were going to just use the 15 for low frequencies alone then you might well want to use the LF version which is designed specifically for this job. Less versatile though.

I don't think there can be any doubt that the compliance of the spider and the surround will change over the life of a loudspeaker and that this will change the Thiele/Small parameters. Without any data (sorry) to back this up I would guess that this would follow a decay curve with rapid changes at first slowing down as the speaker ages but never reaching a point of no further change. I've seen the fs/Qts/Vas argument though the only reference to this in my 4th edition of Dickason this is about manufacturing spread, not breaking in. I've noticed speakers in the past appearing to improve in bass response when new, initially before I read anything about this effect so it was not affected by expectation. I think I have noticed it since but not in every speaker I have built so my observation is this may depend upon the materials used in the construction of particular speakers. I wasn't interested at the time and didn't take any measurements I just wanted to get on with listening tests. The only reference to breaking in I can find in Dickason is "prior to testing, (for T/S parameters) all speakers should be 'broken in'." He goes on to say "resonant frequency can decrease by as much as 15% after 5 to 10hours" and recommends breaking in with moderate cone travel at 25Hz for 1 hour. When I noticed these changes I would have been carrying out listening tests with particular (classical) recordings with a high level of bass in them and A/B testing with my reference speakers, Whether I would have noticed had I not been particularly looking for bass differences I can't say. That's really the crucial question though, would you notice in normal circumstances at a gig and should you 'run in' your speakers before using them in anger? Well I wouldn't use any speaker at a gig I hadn't used for a while at home and to be honest once I've picked up the bass an hour goes quite quickly so i wouldn't really get too uptight about it. I'd love to see any data anyone has though.

Thought so, I've just fitted a new Black Widow into one of these. Of the speakers you mentioned the 15-500 matches your box slightly better than the pro which would ideally go into one roughly half the size of yours. You shouldn't need to re-tune the box either. You realise the response is going to be fairly flat, no 100Hz peak very little mid-range suckout and only a minor peak at the top end. The -3dB points are 40 Hz and around 3,000. This is going to be deep, neutral sounding and lacking in top end unless you add another speaker. Nothing wrong with that, it might be the sound you are looking for. I'd add a 6" unit with a simple crossover or perhaps a horn if you think the top needs more 'zing'.

Just a thought, some time ago I helped fatgoogle who is a regular contributor to basschat design a cab with one of these speakers which was about 150 litres if my memory is any good. It might be worth while asking what his experience was using this cab. Your cab isn't an old Peavey is it?

You'll get 450w into each speaker, but only if you run flat out all the time in practice you won't turn it up full because that will drown out the rest of the band and deafen you and because you have gaps between your notes and you won't play every note flat out. The chances are that if your very loudest point of the loudest note is 900W then your average power will be below 90W and your speakers will be fine.

Don't go for the LF, it is for PA use and is designed for use with a horn speaker. There is something wrong with the Xmax figures since both the 15 and the 15 pro have the same coil in the same magnet. X max for the 15 should be at least 4mm and unless they have done something clever with the magnet geometry which I doubt the Xmax should be identical for both speakers. They used to be identical speakers but the pro had a cast chassis, The pro now has a lighter cone hence the changes in fs Vas and Q. To be honest I suspect tht the figures they give may have other inaccuracies so it will take a while to enter them into winisd and check, I'll do it later if no-one else gets there first. I suspect the sound of these will be little different, the big advantage of a cast chassis on the pro is a slight improvement in heat dispersal and potentially a longer lasting speaker as the chassis is more rigid. Expect to pay about £30 extra for this.

It was just the drive unit in the loft, a spare I picked up when I was using a MarkIV with a 2x15. I picked up an empty cab on fleabay and put the two together. I need to clear out, I can't afford to fall in love with this thing. The empty cab is heavier than my current 1x15. Oh, it sounds nice though, It would just sit in the mix so well.

Just restored an old Peavey 1x15 cab with an old Black Widow driver I had in the loft. Well you have to try it out don't you? What a blast, no top to speak of and a bass best described as 'warm' It just sounded great with the P pup's and some nice bright strings. Pure bass honey. So wrong but so right.

There's nothing to lose by trying the practice amp with the bass turned down with your regular cab. It's not how it will sound in the cab though. The practice amp may be lending it's own tone and you will be using the volume control to balance the speakers. The next stage will be to try the speaker only connected in parallel to your 15. If you get a reversible electrolytic of about 10-20 microfarads and connect it in series this will filter out most of the bass and act as a simple crossover (actually a high pass filter). if you are still encouraged then you could go on to look at a better small speaker to partner your 15 and a proper crossover. The small 'tweeter' will need to be in its own sealed box built as small as practicable inside your main cab. If you like fiddling this will give you no end of fun, it might even improve your sound and you'll learn loads. If you just want a good sound and don't have this sort of curiosity then there's better ways. Me, I'd fiddle. Have fun.

Hey I don't want to get into a big one on this, or get all preachy, I'm as big an idiot as the next person when it comes to my own health and safety but these are public forums and the advice we give is read by hundreds of people so when safety is involved we should be at least factually accurate. I'd hate to think of a fellow BC'er coming to harm through poor advice. Sod it, I'm preaching [quote name='flyfisher' timestamp='1354536188' post='1887005'] Nor would I, but the 'right fuse' will already be present inside the amp because the manufacturer cannot rely on what lay-people put in an external mains lead and, as already discussed, it's quite legitimate for a non-fused mains lead to be used in some countries, so clearly a fuse in the mains lead is not an all-important safety consideration. On that basis, it's quite legitimate for a 13 amp mains lead to be fitted with a 13A fuse, whatever the type of equipment it's plugged into (appliances with a fixed mains cable are a different case). [b]You can't assume the person before you put the right fuse in, the European sockets you refer to are all fused by law but the fuse for each separate circuit is back in the fuse box, they don't use ring mains.[/b] Yes, but how many people get secondhand gear fully checked by a qualified person before using it? Even PAT testing is mostly about earth leakage type testing and certainly won't tell you if the internal fuse has been replaced with a bolt or if the circuitry has been modified. But, again, a fuse in the mains plug doesn't magically make things much safer - or are you suggesting that all our European and American members are at greater risk than UK members? [b]Well their mains is 115 volts lower than ours and all the sockets are fused anyway, if the socket is fused you don't need the plug to be fused as well.[/b] My experience is that mains leads have a habit of finding their way into a big box and people just grab them as needed while putting everything together. This is fine if all the (13amp) leads are (correctly) fitted with 13A fuses but if you have a mixture of 3A, 5A and 13A fused leads then it'll be quite common for the 'wrong' lead to be fitted to the 'wrong' piece of gear and fuses will inevitably blow. What's more, they may not blow immediately because of the way fuses work. Thus, for example, a PA amp with 5A fused mains lead may work fine during a short sound check (depending on its power of course), but if the full-on power consumption is slightly over the mains plug fuse rating then the fuse could blow some minutes into the first set. [/quote] You're right about mixing leads up but very little of our gear uses more than 5 amps even a 1000W PA amp only runs at a fraction of its power (technically if you are running flat out with a 20dB dynamic range then you'll only be pushing 50W a side at about 85% efficiency or 120W, roughly 0.5A so you won't be blowing fuses unless something is wrong) So I know I could bore for England on this but I worked as an electrician for years and in electronics for longer and you don't tell people to use the wrong fuses and expect that there will be no consequences, sooner or later even though the risk is low someone who takes your advice will get hurt. Most accidents happen because of a chain of minor events lead to a catastrophic finale not because of a single large error. Using the right fuse won't protect everyone all of the time and adding one link in the safety chain won't save everyone from electric shock forever but using the right fuse is boringly sensible and telling people not to bother actually opens you up to the distant possibility of criminal liability, should someone take your advice and get hurt. Why would you want someone to take a risk however small.

Personally I wouldn't skip using the right fuse, they are so cheap apart from anything else that you can afford to have boixes of the things. If the fuse in the plug blows first then it can save you the problem of finding an internal blown fuse or replacing a much harder to source fuse on the back of your gear. You are not always so lucky but it can help. If two fuses blow in succession you have a genuine problem which needs sorting. Gear without the right fuse is less safe, Given the amount of gear from the seventies still about and the mods that people carry out over the years you have no guarantee that a lot of gear is wired to modern standards and is safe without a fuse. Think of it as a strand in a rope. The rope might hold with a strand or two broken but you wouldn't trust your weight to it if you knew a strand was cut. Use the smallest fuse possible, as a rule use 1A for every 200W of power, so for anything below 500W use a 3A fuse and a 5A fuse for 1000W with 13A for anything over 1000W . Other values can be harder to track down at DIY/hardware shops.

The radiation of bass frequencies is more or less omnidirectional until the frequency is such that the wavelength is the same as the diameter of the speaker. Multiple speakers behave like a bigger speaker so think of a 4x10 as being like a 20" speaker in theis respect. Being omnidirectional is only about direction though. The sound still gets quieter the further you are from the speaker, It drops off at 6dB as you double your distance from the speaker. With the speakers either side of the stage the sound will be much louder from the nearest speaker than the further one If you were in the front row, you could be 1m from one speaker and 10m from the other. Further out you will hear sound from both speakers. If both speakers are together on the left of the stage then someone sitting in the front will hear more bass if they are sitting that side than they will on the right. Further back it will make less difference ans right at the back most of the bass you hear will be reflected off walls ceilings and floors. I guess this mainly happens when your bass goes through the PA rather than coming directly from a bass stack or whatever. You won't get any difference in total sound produced though.

I'd definitely go for an old 'fridge' type cab, a 2x15 or 8x10 (or 2 4x10's) as they are really cheap second hand and the biggest downside is moving the things, The upside is they are loud so using just 50W is still going to be enough for most situations. If they are just going to sit in a practice room then there is no problem. You may need to rewire to get the impedance right. Something like the Peavey 2x15 which sounds great is 4 ohms as the two 8ohm speakers are in parallel but wiring them in series will make the cab 16 ohms. You are going to get an old school sound, you asked about the advantages of a new solid state amp then it will be more versatile and you have an infinity of choices depending upon your budget. I'd go for a fridge which you can sell on with little or no loss if you decide you don't like the sound. Or build a cab if you have the inclination, it is really rewarding. Don't buy tubes, you can use plastic pipe or thick cardboard tube of the right diameter, try carpet warehouses for the old cardboard tubes they are throwing out.

I've recently gone over to going through the PA and using a small combo for monitoring. Even the guitards have turned down so we now have a lot less to be picked up by the vocal mics. I use a Hartke kickback 10 (discontinued but they still do the 12) which is good because (a) it's a kickback so the sound goes straight to you (b ) it is fairly punchy with not a lot of deep bass so you get the frequencies you need for monitoring. I shove it behind the drummer who loves it because he gets what he needs. Temperamentally I would rather hear what the rest of the band are playing rather than my own tone so the set up suits me. I think the audience get a better sound too.