Phil Starr

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.

I'm glad its working out Steve. There are two possible benefits to doing the ports properly. The noise from the ports, which so far you haven't noticed and also the tuning. To get maximum bass volume you need to tune the port to the speaker and you have now changed the speaker. It works the same way it does on a bass. Pluck an E string fretted at the 5th and the A string vibrates because they have the same resonant frequency, but this only works when the bass is in tune. If your port isn't in tune with the speaker the air inside won't vibrate any more than the A string if it is out of tune and you won't get any output from the port. If you give us the inside dimensions of the cab we can tell you if there is anything to be gained by re tuning the cab.

Reading all this tells me I'm a total malcontent or just unlucky in love. My Jazz bass is lovely to play but I can't get it to sound right, the bass on mine just keeps on going down and there's plenty of clean top to play with but it just seems too characterful for me, however I EQ it just invades the mix and drives the rest of the band out. I've tamed it with flats for the time being but ther is little love there even if she is a looker. I've just bought a Gibson Thunderbird (well it was cheap). Gibson are insane. How could they build such a wonderful sounding instrument and give it that lovely neck and then stick on a body that has nowhere sensible to put the strap. Thunderbird players aren't really all posers, they a wrestling with a guitar that is constantly trying to dash itself to pieces on the floor. The only one I really love is my starter bass, A Cort Action IV which more than matches the jazz for action but sadly doesn't sound good enough with the band, at home though I keep sneaking back to it. Sooo comfortable.

There's a few practical questions to be answered here before you should pick an amp. Is it weight, ease of carrying or bulk which is the problem or a combination of all three? Without a car an amp you can put in your gig bag and a small speaker which is a one handed carry makes sense as it is easy to beg a lift from a band mate if your stuff is small. If it is absolute weight then the AER might be out, it is tiny but fairly dense. Can you go through the PA? This is critical, if you can then your 'amp' becomes just an onstage monitor and you can dramatically scale down. How long term are you thinking? is this a temporary solution to fit your current band or something that you expect to play for years with possibly different bands and at a wide variety of venues? I'll give you a for instance, I've got a 600W Ashdown with a collection of 12's,15's and 2x10's. I use a Hartke kickback10 for rehearsal. About three months ago we were playing in a tiny pub so I took the Hartke and went through the PA. The sound was better for the audience, the sound for the band on stage was better by a much bigger margin. Because the Hartke was only really doing the mids and highs with the thunder coming from the PA I could hear my own articulation much more than usual and played better. I haven't moved my cabs since and i'll only keep them against the days we do outside gigs. The freedom to walk to the car with guitar in one hand and amp in the other is just total liberation. If you can't use the PA then the classD/2x112 solution looks good, you might get away with one speaker only at smaller venues especially if you go for something reasonably loud. Two 12's will solve a lot of the weight problem but not the bulk one. It is probably out of your budget but the AER amp one is the ultimate solution. They are tiny and the sound is genuinely immense in any normal venue, There's some very clever, well worked design going on there.

there is something very holier than thou about the people telling us to just 'develop our ear', just a touch of arrogance. Of course in an ideal world we'd all be able to read music, play scales sing in perfect pitch and be able to improvise in 11/4 time etc Guess what some of us have cloth ears, others have jobs and families and other commitments, for some of us it is just a hobby we enjoy. If tabs help us on the way then what is the harm, actually if they help people get started then that's more than OK it's brilliant and the sometimes inaccurate tabs are done by people who are kind and generous enough to give their mite to strangers. Come to think of it who decided being able to read music notation is fab and reading tab is for thickies? Rant over, sorry. Actually you are allowed to copy small parts of copyrighted material for private study. As far as I know this has never been tested in court for tabs so how much constitutes a small part is completely unclear. Is it just a riff or could you copy the whole part for a single instrument? I feel sorry for UG, as the biggest player in the market they are such an obvious target for the big music publishers/copyright holders they had to do a deal. 911 is just a crawler I found all the 12 versions of Nutbush City Limit chords are the same (incorrect) version I put on UG several years ago interesting that one claims to be a piano piece and some are rated 5* and others 3*!!! Actually most of the tabs on 911 are found on other crawler sites so I guess each time one of the sites finds a tab on 911, 911 will log that as a new version a nd eventually the internet will crash under the combined weight of billions of incorrect Nutbush chords