Phil Starr

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.

Oh the exception to this is the compression drivers on high frequency horns. These have a low thermal power rating usually 20-50W and are often built into 3-400W speaker systems and driven by 300W amps. Distortion is effectively extra high power energy and so burnt out compression drivers aren't unusual. Driving a 20W driver with a 300W amp in the expectation that only 10% of the sound is high frequency doesn't always work.

Please will people stop repeating the myth that low power amps are more likely to damage speakers than high power ones. It has no basis in fact or any scientific justification. If a 500W speaker is driven by a 100W amp there is no way it can be blown by the electrical power. If a 500W speaker is driven by a 500W amp it is only under rare conditions that it can be blown by the electrical power alone. If a 500W speaker is driven by a 2000W amp it would be relatively easy to blow with electrical power, Though not easy if you actually played undistorted music through it. Even the Xmax thing is a bit of a red herring. Speakers coils don't leave the magnet gap at Xmax, they just leave the linear bit of the magnetic field into the less linear bit. At the limits of their movement prudent designers will restrict the free movement of the cone so that it will return correctly to its resting position. It will distort, make a nasty noise if it hits the back of the magnet, it won't give you any extra useful sound but by and large it won't break unless you go on doing it for a long time and depending upon the design sometimes not even then. Speakers mainly break through wear and tear, sometimes through manufacturing faults and very rarely through burning out or over excursion. The myth about lower power amps damaging speakers started in the 60's when amplified music first hit the mainstream. The speakers of the day were unsuitable for the high power involved and weren't rated for instrument use. Coils were wound on paper formers and ordinary household adhesives used to stick them in place. The heat form the coils soon melted the glues and distorted the paper formers so the coils shorted against the magnet and the current increased burning the coils out. Amps can give 1.414 (the square root of two) times their rating in electrical power if their power supply is up to it with the extra 0.414 being distortion. Guitarists introduced very high levels of distortion at the time by overdriving their amps at full power which did blow the speakers of the time. Bassists didn't do this anyway. I'll repeat, the main causes of speaker failure are wear and tear and manufacturing faults. Obviously the more often you play it and the harder you push it the quicker it will fail but a sudden catastrophic failure of a new speaker due to the amp being too big or Xmax being too small is rare to vanishing. I hate it when something said in one forum or said by a salesman in a shop gets repeated as well meaning advice on the internet.

There's really two ways of achieving a sound, the rational, working towards a goal, grappling with the science method and the suck it and see "man that's immense" method. Most of us of course are somewhere in the middle of these two extremes. This is the rig of the suck it and see brigade. Two dozen pedals and actually multiple pre amps (sansamp on the floor), this isn't created by any logical process, this guy just plays through boxes, likes the sound and adds it to his rig. His tech will sort out any problems.

Sigh You know you have two options don't you. Buy earplugs and let them get on with it. Become the grit in the oyster until you get some compromise. The trouble is they have too much invested in their Marshall stacks both emotionally and financially to change easily. They've dreamed since they were little boys about standing in front of these things with their guitars singing and this is living the dream.

Thanks for the answers. It's a real shame, I used to build speakers as a one man business so I sympathize but customer service is pretty important too. If I can't contact you then i can't place an order and i can have no confidence about what might happen if something goes wrong. thanks for the tips though, I hadn't come across Armstrong before. Any other suggestions?

People here have spoken very highly of Wizard. I want a set of PJ pups and could do with some advice so I've rung them, three times, and also emailed. They never answer their phones and no-one has got back to me. I'm now reluctant to place an order with someone who doesn't answer their phones or emails as how would I contact them if there are problems. I'd far rather place an order with a small British company particularly if their pup's are as good as people say but is this a general problem or have I just been unlucky?

Your amp's rating is the maximum power it will give without distorting. Try turning it up high and play a really loud note and listen. If you can watch the speaker cone. The first snap on the string will make the cone jump forwards and the sound will be really loud. This dies away quite quickly but the sound continues quieter and quieter for a long time depending upon your actual bass. The amp and speaker are only dealing with full power for a few thousandths of a second, the first hit of the pick or your finger. The average power to the speakers is a lot less than the maximum power the amp can produce. Two things will break your speaker. Depending upon the design of the actual speaker units the first impact sounds may push the speaker cone too far and it will hammer against the back of the magnet making a loud 'farting' sound or worse still it will go out of the front of the magnet. Good speakers will be designed to prevent this but you can break speakers this way. This isn't in the speakers power rating because it depends upon the detailed design of the cab it is in. The second way is caused by all the electrical power from your amp heating up the tiny coil of thin wire at the heart of your speaker. The wattage rating of your speaker is actually the amount of heat it can dissipate before it gets hot enough to start damaging things. Speaker components can get as hot as an old fashioned light bulb. Because the important thing is the average power and your sound rapidly decays as you have heard and because of the gaps in the music you can generally reckon a 500W amp flat out but without distortion is probably averaging less than 50W. Usually it will be even lower than this. A 500W amp averaging 50W isn't going to blow a 100W speaker by overheating never mind a 400W speaker unless you are doing something else unusual. It might 'pop' the 100W speaker but it isn't going to threaten the 400W speaker in all probability. In any case using this system turned up full will drown out the drums and damage the hearing of anyone standing too close. So long as you don't turn up loud enough to make 'farting' noises or any other unusual sounds and you don't use stupid amounts of distortion/compression or bass boost this combination should go on working for years.

Crackling is likely to come from damaged pots or connectors, poorly soldered joints or cracks in the circuit boards or from the breakdown of components with electrolytic capacitors going first usually but not always. there are safety issues and you would need to check the power supply caps are discharged before fiddling around inside the amp. there are several thousand connections inside the amp and resoldering all of them is more likely to end up with you creating other problems especially if there are surface mounted components. You will need a specialist soldering iron with a very fine tip and thermostatic temperature control. You can often find the fault using a freezer spray but even this is a moderately skilled job, if you can read a circuit diagram and can solder then fine but if not you will probably struggle. It depends upon you, if you are happy to spend long evenings learning loads of new skills then what have you got to lose, if you want an amp that works then you will have to pay someone who has spent the long evenings learning this stuff.

This is all getting a bit unreal. When I used to make speakers I paid rent on a workshop, paid bills, bought machine tools etc etc. There's labour costs including the fact that only a fraction of your time is spent making speakers, You have to factor in design time, marketing effort, paperwork dealing with customers etc.etc. You don't go to a good restaurant and expect to pay for just the ingredients, you know that a team of highly skilled people have spent all day prepping ingredients to serve a couple of hundred meals and that the posh surroundings don't come cheap. there's probably nothing to cooking the meal that you couldn't do at home. It would just be a lifetime's training to reach the skill level needed. You probably could build a cab like the Barefaced for £75 but calculate how long it takes and add in the labour costs (what do you pay your plumber or to get your car fixed) and you'll realise there isn't a lot of profit in that £450. You'll need to sell a lot of speakers to make a living.

I'd forgotten this thread. First of all yes i would definitely port the cab. Your amp will overload the 125's but this is more due to over excursion than the thermal load. Having said that they suit your cab a little better. In practice it depends upon how you use them. I've used two with a 600W amp but I tend to leave the bass flat or even cut a little and I don't play in a very loud band. I can drown out the drummer and so it is plenty loud enough for me. If you use a lot of bass boost or are heavy on the volume there is a small risk. How easy would it be to get replacements? If you wnt to be idiot proof the 300's take you well beyond the thermal limits and with the extra air in your cab the speakers are less likely to go beyond the excursion limits. They are going to have an extended bass with a slow roll off in this cab so they might be a bit 'polite' sounding though the bass will be clean and deep. If it helps I've been gigging a lot with the 300's in a 2x10 but I'm swapping them out for the 125's to get a little more character. The 300's are cleaner and will be going into a pair of wedges.

Hi Lawrence, the difference in Xmax isn't that great with the different measuring techniques, I've been developing some cabs for 15" deltalites with 4.2mm Xmax and with some cabs I'm getting excursion limiting at 35W at some frequencies. I'm kind of with BFM on this one, With only two 10" speakers Xmax of 2mm is a potential problem, even if it is 2,6mm in real money. The high resonance is also an issue, though not necessarily a deal breaker. If Fs is 73 then in a cab it will be higher, probably a whole octave over E or more. There will be a hump between 100-150Hz somewhere to compensate but this will give the speaker that sound which so many commercial cabs have. If what you want is that particular colour to your sound then it isn't a problem, in many ways it is the old-school sound. If the OP wants that sound then great but he should know what he will get with the Celestions when there are other more neutral speakers at that price point. That Sica is awful though.

On mine there's a speaker jack deep inside the back next to the power socket which connects the internal speaker to the amp. You could unplug this and plug into any speaker of 4ohms or higher. If you used a Hartke 4x10 with the same speakers in it you should get an extra 6dB using the same power from the amp, equivalent to turning up 2 or three notches. I'd only really do this if I was going to upgrade anyway or if I was able to borrow a spare speaker from someone. If you were looking to upgrade anyway you could buy a cab first and just use the Hartke as a head until you had the funds to buy what you wanted. But, yes I'd look to either buy a bigger amp for gigging or decide I was going to go through the PA, the Harke will do fine as a stage monitor if you really like the sound but it needs some PA backup.

Don't go for the 100W Celestion it has a smaller magnet and isn't really going to be suitable for your cab. Do you have to have an 8 ohm cab? A 4ohm cab means you can use 8ohm drive units and there is a wider choice available for you. I cant find that exact model on Celestions web site. the BL200X (8ohms) gives an Xmax of 4mm but at a lower sensitivity than you give. It may be worth contacting Ashdown and finding out what they would charge for repalcement speakers. Rumour is that they are not too expensive and you would get the sound of the new speakers you tried if you use the same drivers.

You kind of need to give more details, is price a factor? do you have a budget in mind? how about size and weight? some speakers are more suited to compact cabs than others. One of the things you seriously need to look at is Xmax, basically how far the speakers can move before the coil exits the magnet. There are plenty of speakers out there (eminence and celestion amongst them) which will handle 600W of heat but only 100W of deep bass because they are excursion limited. I haven't time tonight to look anything up but maybe you could give a few more details of what you are looking for.

I've got the kickback 10. Neither of these cabs will go terribly loud. You are pushing only 120W through a relatively small cheap speaker. They are excursion limited and you can see the cone working like crazy. At low frequencies they will move beyond their recommended limits (Xmax) and 'fart out' Probably best to turn down if this happens, it won't get any louder anyway and you will break the speaker fairly quickly. You say you like a warm tone, I suspect you are using some bass boost, even a little bass boost means the speaker will overload more quickly and turning to 3 o'clock will halve the volume available. Shoving your amp back against the wall will give you some natural bass boost and pushing it right into a corner even more. If you do this you can cut the bass on the amp and get more volume before it distorts. I would only expect a kickback to match a quiet to medium drummer in a small room, they really won't give rock volumes at a gig. Plugging in a better speaker will give you a lot more potential volume but you can use them for gigging. I run mine with bass cut on stage and use the DI out into the PA where I cut the top and boost the bass. This gives me a nice clean sound on stage and kicked back I can hear really well. The audience hear a really full sound from the mix of backline and PA. I like this set up because it stops most of the bass feeding into the vocal mics and takes up less space. I retain the tone shaping on the Kickback which I quite like.

Ok the speaker has a coil inside the magnet which is what makes the cone move when the amp pushes electricity through it. The coil has a resistance because uncoiled it is a long thin bit of wire and thin wire resists electricity. Coils do something else though they have inductance, they resist the passage of high frequencies and the higher the frequency the more they resist. So to work out the total resistance you add the two together, resistance and inductance and this gives the speakers [b]impedance [/b]which is what the manufacturers give as 4,8, or 16 ohms. This means the impedance is always bigger than the resistance you measure. Actually as it varies with frequency an 8ohm speaker may be less than 8 ohms at one frequency and 80 ohms at another. If you look the specs of drive units they usually say [b]nominal[/b] 8 ohms. If you look at a graph of impedance you'll see what I mean [url="http://www.eminence.com/pdf/Kappalite_3015LF.pdf"]http://www.eminence.com/pdf/Kappalite_3015LF.pdf[/url] If you have two 6ohm resistance speakers then they are 8ohm units and the cab is probably 4ohms or it could be 16ohms.

You need to think about what use you are going to put them through, just vocals or will the band be fully mixed? FWIW I use Yamaha S112V's and i'm pretty happy with them The bass is OK (but I wouldn't want to put the bass through the PA without the bass bins) The horn is a real gem though and vocals really cut through. I've not heard any better vocal sound from bands using gear in this sort of price bracket. Worth a read [url="http://www.performing-musician.com/pm/dec09/articles/pabuyersguide.htm"]http://www.performing-musician.com/pm/dec09/articles/pabuyersguide.htm[/url] You probably know all this but [url="http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_live_sound_speakers_and_amps.html"]http://www.ultimate-guitar.com/columns/gear_maintenance/a_guide_to_live_sound_speakers_and_amps.html[/url]

I've used the mixers and the EP power amps and had no trouble at all. Talking to some of the dealers after sales support is almost non-existent though. Thomann's support might be worth having here. I once played through a behringer 2x10 combo. Sounded awful. I think i'd avoid cheap speakers generally though, too much of the cost of a speaker is down to materials for you to be able to make a cheap one without cutting corners

It may also be a problem with those speakers. 4x10's will always be bass heavy and top end light because of the way the multiple drivers work together. Even slightly to one side and the top from one speaker will cancel the sound arriving a fraction of a second later from another speaker. Unless you have the speakers angled so they are pointing directly at your ears you'll not hear most of your top end. It's really unlikely you aim the speakers at your drummer so he isn't going to get any of your top. Adding an extra 15 (also very directional) is only going to make things worse. You can test this at your next practice by resting the 4x10 against something so it points at your ears and the 15 so it points at the drummers ears. That doesn't mean the other posts aren't true of course, it may be eq etc etc, maybe a little of everything.

This is either a wind up or you are seriously richer than the rest of us. If I had £1500 to spend on gear for home use most of it would go on a bass which would give me much more pleasure to own than a nice amp. I use a Hartke kickback 10 which cost me £125 and sounds great in a small room. That leaves £1375 towards the dream bass. If you already have a bass fund (£5,000?) then my dream amp would be the AER Amp One which is small, heavy and sounds like a dream. It will also do gigs if you change your mind. About £1,000. Wish I had your problems.

Just a thought, the head isn't the only thing controlling your sound. The bass and the speakers will have more effect than the amp. Have you tried the ABM with other speakers, if not it might be worth taking it into the shop with you and trying a range of speakers with your amp, if you are thinking of spending Ampeg money they should be pretty helpful. Good luck in your search.