Phil Starr

The majority of cabs like these have an active crossover and two amps, one each for the bass unit and horn. You aren't going to be able to use a slave with these. The LD units have looked like great value for money for some time so definitely worth checking out.

Welcome to BC. You know the answer to this, if the pot is scratchy and you are going on tour then it has to be replaced, you can sometimes clean them up with some Servisol (switch cleaner) but it is often a sign of wear and only a temporary fix. It will of course fail mid gig in the middle of nowhere at a weekend if you don't sort it first. Sorry

Good Luck, I started playing bass from scratch at 55 and was playing in public within months. I'm now in two gigging bands. The only thing you can do to keep the nerves under control is practice,boring but it helps. Once you get to the end of the first song you'll find it easier. Make sure you enjoy it, it is over so quickly.

[quote name='jonunders' timestamp='1330297222' post='1555489'] I'm sooooo glad i read the wiki article, everything is now as clear as mud! [/quote]It is pretty hard to explain something as technical as this in simple terms. One day I'll have a proper go. Mr Foxens analogy is as good as anything. I'll attempt something in between this and the wiki article. You need to understand the way the amp works just a little The sound from a speaker is made as the speaker moves forward and back in time with your strings vibration. To make it do this the amp increases the voltage to push speaker cone forward and reduces it to let it back, at some point the voltage then reverses and the speaker moves further backwards behind its starting/resting position. The simplest way to do this is to have a single output transistor or valve doing the whole process. This is class A. The problem with this is that when the speaker is in the halfway position the voltage and current in the amp are also halfway so the amp is working pretty hard when the speaker is in the resting position doing nothing. This means class A amps get very hot even with low signals as all that energy has to go somewhere. As a result class A amps tend to be low powered and inefficient as it is the heat that kills transistors and valves. The next trick is to split the signal so one device does the positive side of the cycle and another does the negative side. This is class B. Now when the speaker isn't moving neither transistor or valve needs to do anything and there is no energy to disperse as heat. This makes class B amps more efficient and more reliable. The problem now is the point where you switch from one transistor/valve to another. The output devices aren't very linear at the bottom end of their range, there's always a bit of a gap and you end up with distortion when they change over, This is really noticeable in the quiet bits of music or whatever. The solution which worked for years was to have both output devices working at the crossover point, meaning you had a class A amp at this point filling in the gap and class B for the loud stuff. This is class AB. This is still the most common way of doing things though it is changing rapidly. The next way is to control the sound by switching the output devices on and off very quickly. This is class D. By switching them on more than off you get more current and therefore more power and less by having them off more than on. Because transistors make really efficient switches this means less energy and so the manufacturer saves on expensive heatsinking and supermassive transformers. this means class D is cheaper for really powerful amps. so your PA amp or anything over 200W is likely to be class D. Class H (orG) is using a different trick of varying the power supply voltage in the amp to make it more efficient again saving on heat problems and expensive power supplies. The reality is that you don't need to know any of this. You won't find a class B amp. Guitarists might have a class A amp or even one they can switch from A to AB. Some people think a class A amp sounds sweeter. Typically switching from class A to AB means the amp will go from 7W to 15-20W. Bass amps won't be class A unless they are nutty 'boutique amps'. (discuss). You'll get class AB, D or H. It won't matter because you'll be playing and not designing the thing. They do have different distortion characteristics but you aren't intending to distort by overloading the amp anyway. It is more important that they are well engineered rather than what class they are. Hope this helps

Hi Tom, I hope you are going ahead with this project. If you haven't already chosen your drivers then I'd like to add a bit. For any given driver there is an optimum solution both in terms of cab size and tuning frequency. For example you really want your port output to be tuned to the speakers resonance so that you get maximally flat responses and the cabinet size needs to be adjusted to achieve the optimum damping of the speaker. Any of the speaker design programs will recommend the optimum cabs and tuning and the better ones like WinISD will allow you to see what happens with a less than optimum alignment. Generally speaking if you wanted a flat response down to bottom E then you would start with a driver with a resonance below that point. This means a heavier cone or a softer suspension and usually means lower efficiency. It also means your speaker will have to be designed with a longer excursion to cope with these low frequencies. If you want a smaller box then you look for a driver with a bigger magnet for better electromagnetic damping to compensate for less damping from your box. Also look for low Vas. I wouldn't get hung up on deep bass, speaker designers talk about cut off frequencies but the speaker doesn't just stop here, there will still be some sound but at lower levels right down below 41Hz and the bass is often reinforced by boundary reflections from floors and walls in real life situations indoors so a lot of deep bass can be difficult to manage. The character of your speaker is going to be more determined by any hump in frequency response above 100Hz and the midrange peaks which both the Eminence drivers show. I haven't modelled these speakers but it looks as if the deltalite is better than the basslite by a small amount probably proportionate to the price difference. If you decide that you are going ahead and it isn't too late I will run them through winisd and give you more detail. Cheers

[quote name='Mr. Foxen' timestamp='1329860810' post='1548819'] Speaker could have died, shorted and taken out the power section. [/quote] That's right too, but it is more usual nowadays for speakers to go open and not short circuit and the protection circuitry should protect the amp. It may well be that a speaker short will have blown an internal fuse. It is pretty hard to say without the amp in front of me

Just to second JTUK,, It's possible the amp and speaker are both blown but unlikely. The problem is, and I know nothing about this particular amp, that separating amp and speaker for testing might need breaking into the case and an hours labour, only to tell you its bust and can I have £30 please. With a low value combo they probably didn't think it was worth spending your money on it. You could either try another tech or go back and ask them if they tested amp and speaker separately and if they didn't then how much would it cost. Then you can decide if it is worth the risk. Recieved wisdom is that Behringers are hard to source parts for though I've no direct experience.

Try recording the sets and playing it back to them the gaps are pretty shocking. It's pretty disrespectful to the audience to constantly retune on stage and I don't think they realise quite how much time they take up. Are they playing drop D or DADGAD or something, then get a second guitar or run the set so the retuning only has to be done once or twice. In the end I run an extra mic for me and we banter whilst the guitarist sorts himself out. Not perfect but better than ignoring the audience. Sometimes it seems like Ken Dodd could do his whole routine in the gaps.

[quote name='crez5150' timestamp='1329690270' post='1546103'] [/quote]lol

It's an amusing idea. This is how it works. Your guitar gives out about 1/1000 of a volt from the pups. Your effects pedals may boost this a little but the most they will boost the voltage up to will be about 1V (most won't go anywhere near this) The maximum they could possible create by chaining them together (a la Bart Simpson) would be about 2.8V if you are running off a 9V battery or supply. Above this the battery runs out of volts. The battery won't let you have very much current either. You won't run 100W out of a PP3! The amplifier takes the signal of around a volt and boosts it to 30V for a 100W output. It also will do this with all the current needed to provide this power. You've got slightly mixed up between gain and power.

Most of us operate with one or two monitor mixes if we are lucky. Learning to pick what you need from the jumbled onstage sound is a skill you have to develop early for the average pub band. In the days before monitor mixes I used to split the bass and guitar stacks so the guitarist would have one of your 4x10's and you would have one of his 4x12's in your stack, That would enable you to hear each other. The other thing would be to buy a little powered monitor which you could feed from one of the other mixes, the guitarist's as has been suggested or even the FOH mix

There really should be no more problem with this than doing exactly the same with an electric bass. You wouldn't put an electric bass through a vocal PA with 8" speakers and yes, you can run out of headroom much more quickly with bass frequencies so a decent amp and speakers are required but bottom E is still the same frequency. The only difference I can see as an engineer is getting a clean feed of your sound and a double bass is much more prone to feedback so you need to keep stage volumes down.

Saw you at the Pen and Quill the other day. Loved your playing. good band.

IMO it is a great idea if you don't mind lugging around all the extra weight. I dread to say it but there is a bit of mythology on this site about mixing speakers. Using multiple drivers does affect the sound and so does mixing different drivers, whether they are the same size or not. The effects are complex but predictable and you might like the sound or not. Mr Foxen is right though if you have a 4x10 then most 15's or even 2x12's will be lost alongside them. the first consideration is to have them operating at similar sound levels. The key to this is your crossover. If you are feeding different signals to your two speakers then you can adjust the volumes separately to match the sound the way you want. The first question is what sort of crossover is it? Is it a full blooded electronic crossover with variable frequencies? does it have adjustable roll off? Is it just a sub out at a fixed frequency and if you use it does it cut the bass to the rest of the speakers? You do realise you will have to buy a second amp if it isn't a stereo amp. As to speakers, don't get hung up on size. Since these are only handling the real bass and you want to get your tone from the Peaveys you are building subs. This means you want speakers that can shift a lot of air, which have long voice coils and a large surface area. This means you are looking for speakers with a long Xmax (better than 4mm, the bigger the better) and you can probably look at PA drivers as most bass instrument drivers are compromised by the need to reproduce the rest of the bass. I'd be tempted to build the sub and try it with the Peaveys (and the Epifanis? ) If I liked the sound I might then look at a way of reducing the load by building a 1x10 or a 2x10 to make it more portable. I might even end up with a 15+10 if a single cab could give the sound i wanted. You'll need to learn quite a lot though to design your own cabs. It's not rocket science but it is probably 'A' level physics, unless you use someone else's design. You'll get advice here. Lots of advice!

It's a bit like saying you are going to improve the handling of a Porche by fitting some bigger shock absorbers from a double decker bus. The cab and speakers are designed to work together. It'll work,in the same way as the shocks would work from a bus but it is pretty unlikely to be an improvement. You can make home build cabs as good as or better than shop built ones but you either have to use a recognised design or learn how to match speaker and cab. If you are the sort of person who is happy to learn and experiment and risk going wrong sometimes, it is really rewarding but you've got to build the cabs for your drivers not try to recycle old cabs. Aren't Epifanis a bit expensive to just use as timber? Go onto the Eminence website if you want to read more and have a read of some of the build diaries on here. If you decide home building is for you then we'll give you some more links. Believe me you'll get plenty of advice in this forum. Cheers

Four chords, what's not to love? Guilty as charged. Bet you all do Crazy too.

I've got them (diamonds) in 4 different grades, I'll stick to the finest. My stones get a lot of use so they don't stay very flat, one of the nice things about diamond hones is that they are pretty flat and stable. Thanks for your help again.

[quote name='lettsguitars' timestamp='1328460127' post='1527369'] Strings off. Truss rod adjust to get dead flat (use a straight edge), mask off the board, permanent marker along the tops of the frets. level frets with 320 grit paper stuck on a flat thing (the marker shows where your high/low spots are), recrown with sanding pad (the easy way), polish with wet/dry to 1200 (concentrating on the fret sides not the tops) then buff with jewellers rouge. There's nothing to it, but it's hard to explain without physically showing it done. There are numerous youtube videos that are pretty good. No reason why you can't get very low action providing the neck's a good un. You do get problem necks that obviously need a little more work, relevelling the board etc. Hope this helps. [/quote] Thanks, sounds scary as this is a new bass for me. I might see if i can go on tweeking before I try it. Could I use my diamond hones I use for sharpening plane irons? they measure about 8"x2" and are meant to be dead flat.

I'm not saying the Jazz is awful, there's a surprising lack of care in it's assembly though. It is bottom of their range and the bridge is just a piece of pressed metal. The springs don't meet the saddles and the grub screws slide around on the chromed surface, part of the reason why the tuning isn't very stable I think. The neck is maple with a rosewood fretboard just like my Cort I'm not that bothered about a low action as it happens and thanks to your advice I've reduced the relief on the neck so it is almost straight (thanks, you pointed me in the right direction) I'm just surprised that this guitar is 5x the price of my starter bass but plays less well and is just less well made. I bought it for the sound and this is great but I'm wondering if I shouldn't have just replaced the pup's on my old Cort. I'm thinking in future I might just replace the Precision pup's on the Cort and use that rather than look out for a Fender P.

Or as Bill says go on the eminence site

Ok if you want cheap and cheerful then make a cab of 100litres + a bit to allow for the volume of any bracing and the speaker and port, say 110 litres overall. Then put a port with the dimensions I suggested in. The dimensions are internal so don't forget to add on the thickness of the timber you use. Something like 50x73x30cm will do for the internal dimensions and you can make the port out of plastic soil pipe from a builders merchant. Good luck

Hi Lawrence, I've straightened the neck a little and raised the action at the bridge now, it isn't far short of straight. The bass is only a few months old so it isn't wear. I've no idea how good to expect the action, the guitar tech at my local shop said if you want a Jazz with a low action then don't buy a Fender. I love the sound of this bass, the neck profile is a joy for someone with hands like mine and it is very pretty but it doesn't seem as well made as my £200 Cort. Lots of little things, like rough edges on some frets. The nut wasn't properly filed and it doesn't stay in tune like the Cort. The finish is nowhere near as good and the bridge is so poorly made. It's a USA one as well but it just looks like there's a lack of quality control. Is this normal with Fender?

Hi, I'm having problems setting up my Fender Jazz. Neck relief is slightly concave, pretty much the same as my Cort. I'm getting Fret buzz between the 7th and 12th frets (roughly speaking as it depends upon the height of the action I set.) To lose the fret buzz the action is too high. It has been back to Manson's once but it hasn't really solved the problem. I kind of like to understand problems and to be able to solve them myself if at all possible. Any suggestions?

Hi, you are getting good advice here. Bill designs speakers for a living and I used to design speakers. There's no disagreement between us because the maths/science points in one direction. The delta 15 isn't a great choice of speaker unless you want a very coloured sound. You may have chosen this because you've heard one and liked it or because you have some theory you want to chase. If you've chosen the delta on price or because of some sort of deal then we are telling you that there are better speakers out there. If you want to go ahead then the 100l cab I suggested seemed a reasonable compromise in the few minutes I spent modelling this speaker. Any larger and it will become a monster you never want to move, much smaller than this and it will have a huge bass hump that swamps your sound and you will lose all your deep bass. As it stands this would peak at nearly an octave and a half above bottom E. In any case Bill is telling you that this speaker is excursion limited at low frequencies so that the speaker will start to distort at 50W and may have a short life expectancy. I'm a great believer in getting on with building your own cab, you learn so much from it, not least your mistakes but if you want a reasonable result then it is good to listen to advice. You won't find good designs for this speaker because anyone who can design a speaker will know enough to choose something different. Speaker design is all in the maths and only the maths, you have to at least be able to drive the computer modelling programmes or understand the books/internet articles. if not then you might be better to use an existing design including using the drivers the designer has selected. Tell us why you have chosen this speaker to use and we might be able to offer more help. At least we will know where you are coming from and what you are trying to achieve.

I think the OP is wanting to carry as little as possible to the rehearsals. Rehearsals can be for different reasons, if you want to test out your stage sound then you have to take all the gear you will be using but if you are just working on songs then I'm a real believer in keeping the volume down. You can just simply hear so much more and if that sounds 'wrong' whilst you are playing then it is probably because it is wrong, as someone has said. Because our hearing is logarithmic doubling the power only gives an extra 3dB of sound, noticeable but not dramatic. Ten times the power only gives 10dB which subjectively is twice as loud. A 200W amp is only twice as loud as a 20W amp. That's why you are getting so much variation in power suggested. If you are using 200W into halfway decent speakers at a rehearsal in a small to medium sized room then, unless it is turned right down you should be wearing ear defenders. There's something slightly mad about carrying in a huge amp and speakers if you have to turn it down or block it out provided you can afford an alternative.