Phil Starr

Looking good, let us know how you get on at rehearsal.

Video? oh goodness! It has gone hasn’t it! let me sort that. i actually have a great follow up to record too! Thank you both. I've tried it in the practice room with everything turned up to 11. it really works and you don't feel cut off from the room. Rehearsals next.

There are actually two questions hidden in here. One is simply about shopping; I need a loud light cab, tell me which ones I should be looking at. The second question is about power to weight ratio and you are spot on, it is about sound output and not about how many watts the speaker can soak up. Sound output is a tricky concept as it is about frequency as much as absolute output. Our ears are much more sensitive in the frequencies of the human voice, one hundred times more sensitive more or less, that's why guitarists are so damn noisy A lot of bass cabs have some mid boost baked in, they are going to sound louder than other cabs without the baked in sound. The other thing is how much bass do you want and where do you want it. There isn't much bass in the output from a bass guitar surprisingly and very little at all below 50Hz, in fact you can generally filter it out without the audience noticing, in fact in a live situation you can usually filter it out without the bassist noticing. In terms of lightweight cabs that means you can reduce the size of the cab if you sacrifice deep bass. There's an added bonus too, you could lighten the cone if you know up front your design won't do really deep bass and that can raise the efficiency of the speaker. All I'm really trying to say here is that some cabs sound louder because of the tonal balance of the cab, if you don't want or like that tone it isn't a sensible buy for you. Always buy a cab that sounds good to you. Power handling isn't a sensible way to look at power to weight ratio. Some cabs are easily 10x better at converting watts into decibels compared to others, and decibels are what you want. Typically bass cabs vary by less than that and though there are exceptions youd expect most cabs to vary within a 94-100dB/watt range. that simply means the better cabs might give you 100dB across most of the frequency range for a 1W input and a lower efficiency cab might only give you 94dB. This is all standing straight in front of the cab and just a metre away. That 6dB is significantly louder, you'll absolutely hear a marked difference but it's not going to be twice as loud, just louder. That's at one watt, you an add more decibels by turning the tap up at the amp, at 100w they will both be a lot louder but there will still be a 6dB difference. The loudest sound they make will depend upon the power handling and the efficiency combined, how you hear it on the tonal balance as well. So lightweight? Small cabs, lightweight cab materials, complex bracing and lightweight neodymium based speakers. All adding to the cost (OK except the smaller cab) Efficient cabs, big cabs, large cone speakers or lots of speakers, large speaker magnets. Ultimately you can have light and loud but not light loud and cheap. If you are contemplating shopping though the best bet is a shortlist and then trying them

Thanks for this Dan, I only just stumbled on it and had to try the idea straight away with my H4N. It works brilliantly in the practice room, can't wait to try it out at rehearsal and at a gig. I may not lose my hearing after all. Oh I can't find the video, any chance it is still available somewhere?

There are a couple of places you can buy the RCF 310 Mk3 at just under £250 at the moment. RCF have introduced the Mk4 version so the 3 is a bargain, I bought two as monitors and PA use for our duo. They work well and at some time I will get round to trying them as PA (with subs) with our rock band. For the duo I go straight into them with the bass and at those levels it all sounds good, both DI'd (I've a John East J-Retro on the bass for tone shaping) and also when running through a Zoom B1ON as amp sim. I have thought of trying them as a pair as bass stack but IMO you would be pushing just a little too hard to get away with one playing alongside a full drumkit. It's pretty much the same as with a bass combo, a single 10 just isn't quite enough to get the sound levels a good 12 will just about make it at the current levels of technology.

That's about right from Islander. It isn't worth wasting time if you haven't cleared the problem after a couple of goes. I only asked about the spray because there's an increasing tendency for modern pots to have the two access points sealed. I've had some problems in the past with decoupling capacitors going short circuit with age, or otherwise being troublesome. The effect is to cause DC to appear across the pot and cause sparking problems which create noise and even pitting. If your amp is really old I'd look for any signs of leaking capacitors. The other problem is that the spring on the wiper inside the pot just weakens making contact less secure, often combined with dirt ingress so just cleaning the track is often only a short term fix. the biggest part of any fix is opening the amp up and removing the board. Once you get to that part replacing components is often just the quickest simplest fix. good Luck

Is the Servisol actually getting inside the pot casing onto the carbon track? A lot of people just spray in the general vicinity and it can't clean what it can't reach. Having said that 'clicks, pops and bangs'? That sounds like more than the sort of crackly noise you ought to get if it is just a bit of dirt.

I think you have to think this through, the Feder combo is £500+ and the Ampeg £450+ if you are asking can a cheap Alto or Mackie Thump do the same thing better then the answer is no. Could the RCF 315 at £430 do the job then, yes it could. There is a saving to be made by going the PA route but you won't get the same quality for half the price. The main thing though is the difference in sound, good PA speakers are designed to put out a good copy of what you put in. Bass amps are made (hopefully) to make basses sound good and that usually means a little bit of colouration. Your first step ought to be to audition the candidate systems to see if you really like the PA/clean sounding route to the traditional bass amp. If you do then there are advantages in terms of flexibility and a small cost saving, but beware, cheap PA cabs have to cut corners and that usually means in bass handling.

Reverts to old man reminiscing. I used to build these in the days before Thiele Small. the biggest problem in those days was just being loud enough. Amp watts were fiercely expensive and heavy for touring bands. Speakers had primitive treated paper formers and glues which only temporarily held the coils together so efficiency was all. I dread to think what the frequency response of the old W-bins was but very little mids and treble escaped those folded horns. I remember some bassists using them without an HF horn too. With vocals through a 4x12 there was little but very loud mush. It was fun making it all up as you went but thank goodness we don't build them like that any more.

As stated just the cabinet, the grille is missing. Would suit as a project for someone who just wants a cheap cab or with a Black widow driver to sit in a practice studio. These cabs sound great but are too big and heavy for any sensible gigging band. I could source a drive unit for someone who wanted it but that wouldn't be free. Just come and collect from Chard Somerset, it will go into a skip in a couple of weeks.

The answer is the same as for an active PA speaker really. Any decent PA cab will handle the bass and a FRFR response (yep response twice) will give you an 'uncoloured response and a good basis for amp modelling or eq. The trick is to get a good passive PA speaker cos the cheaper ones tend to have underspecified bass drivers. PA gear has come on a lot recently and a fair bit of the older kit did have limitations. Equally there is a lot of very decent passive gear out there that isn't fetching much of a price on the used market, so there are lots of bargains. The downside is that most of what you find will be fairly heavy wooden boxes with huge ceramic magnet drivers, the old cabs have passive crossovers of varying quality so they don't sound so good pound for pound and the most modern PA cabs have DSP built in so the responses are generally almost unnaturally flat. I can't resist playing bass through any speaker that passes through my hands, the old Yamaha S115V is a good contender and uses bog standard Eminence drivers with little light bulbs as protection so both bullet proof and repairable.

Having said earlier in this thread that my Wharfedale PA speakers had been faultless to date the inevitable happened and a speaker went down. To be fair it is almost twenty years old and blew when someone else borrowed it. However I took it apart and was very impressed with the construction. Cabinet is way too heavy with 18mm MDF but very well constructed, the amp is nicely made and very well over specified with 10 output transistors. The blown driver is nicely made too with a substantial ceramic magnet and a nicely made deep double roll surround. Best news of all is that although this particular speaker has been discontinued for several years Wharfedale still carry spares which are reasonably priced (cheaper than an Eminence or Fane equivalent) and available by return of post. That's great service in my book from an old UK firm (IAG who are Quad, Wharfedale, Audiolab) If this is their aftersales then I don't think the company is one to worry about

This is the best place I've found http://speakergrills.co.uk/

Thanks Johnny. All done I need to be able to type faster

You poor thing. I hope it wasn't too dull. Though I admit I just looked through to find any useful information for you and did get distracted by some interesting contributions from people. The big problem is that a lot of the links have gone down which happened when the Basschat site was moved. I've not got all of them saved either so difficult to put them all back up again. I never did do the step by step guide but I did build a slightly smaller version and put up a video of the build (link to follow) As ever bass playing and band changes get in the way, I love Basschat but prefer bass playing The external dimensions are 360x424x530mm the baffle front is set back 30mm from the front of the cab so internally the depth is 306mm. The four ports are made of standard guttering downpipe 190mm for a 50Hz tuning. All this information is elsewhere in the thread but it's probably hard to find. The techniques are the same as the ones in the video. I'll try and see if I can find any old pics and plans to put up but if you want to build one of these then I'm happy to guide you through the process. If you had been here a week ago I could have sent you one of the prototypes. Sadly someone else has bagged that one.

PM'd

If your output has a 5.3 ohm tap then it will be equally happy with either a 4 or an 8 ohm load. Like I said its 1/3 away from both so effectively 5.3ohms exactly in the middle between 4 and 8ohms. Either will work fine.

I wasn't going to answer this question because there are probably people who know the gear you are using way better than I do, but as Al mentioned me I'll put in my little bit. Very roughly your bass puts out a few thousandths of a volt, this is increased inside the amp in stages so after it has gone through the pre-amp it increases roughly a thousand times and at the master volume it will be around a volt, this feeds into the power amp where it is increased to tens of volts (and lots of current but let's keep it simple) This increase in voltage is called gain. If your bass gives out 5/1000V (5mV) on the loudest note and your amp can make 50V (just over 300W into 8ohms) then the gain is 10,000 or 40dB. Nearly all amps have enough gain to drive the amp flat out plus a little bit more, they don't know which bass you are going to use and gain is cheap so giving you spare gain is normal. Some amps use extra gain to impress/fool you; if the amp had a gain of 100,000 it would be as loud with the volume set to 1 as another amp set to 10 in the music shop. If you don't know you'll be very impressed, 'it's a really loud amp, way better than that other one'. The trouble is that if you turned it up to 10 then you wouldn't get any more power, just distortion as the power amp can only give it's maximum voltage and current and they are fixed. So what I think is happening here is your Ampeg has a lower gain than a lot of other amps, so you need to turn the volume and gain up to get all 150W. I know Skidder and if he says the pre-amp makes it louder then I absolutely believe him. (Jefferson Archive, his band are so loud it hurts ) It won't hurt to have everything cranked to 11 so long as you aren't getting a load of distortion, that's just the way your amp is set up. If you want a pre amp to get a bit more gain then go for it but the maximum volume will still be the same, just with your controls at a lower level. You don't need a bass pre amp to test this theory, you could use a PA mixer, guitar effects unit or anything with 10dB of gain between the bass and amp and see just how loud your Ampeg will go before spending any money. If you want a cheap pre amp how about https://www.gear4music.com/Guitar-and-Bass/Behringer-BDI21-V-Tone-Bass-Preamp/6LV

Hi Marco, 5.3 ohms, that's a bit specific. You won't find anything out there at that impedance unless it's home made. You'd only get that with 3x16 ohms speakers in a cab. That won't matter, your amp is valve you say so it'll have a matching transformer. If it was originally built for a 3 way speaker it might be matched to such an odd impedance or it may be set to that so it will work equally well with a 4 or 8 ohm impedance. (it's 33% away from either, and the matching isn't that critical) Do you have other impedances available? that will be marked on the back of your amp. If not then for convenience I'd go for a single 8 ohm cab, with your amp you'll get the same volume out of either and if you ever want to add a second cab another 8ohm cab will work fine.

I've no knowledge of these models but Wharfedale's PA stuff is the best bang per ££ available IME. I currently use a Wharfedale EVP PA with RCF's as monitors. The difference in quality is there but not as great a difference as the price would lead you to expect. Everything has been faultless to date and the Wahrfedales have to be 15 years old so probably not too much of a risky buy. It's not like they are an unknown brand. Andertons have been OK with me when I've returned stuff in the past too. It all depends upon whether you like the way they sound though.

I'm assuming this is a serious question. The only fair test is to change only one variable at a time so if all you want to know is what the amplifier does then that's the only bit you'd change. If you change both the speaker and the amplifier you won't know which may have contributed to a change in volume. So long as the speaker can handle the signal without compressing you should get your 4.77dB extra. If you change to a speaker with a lower sensitivity it will be quieter with both amps but you'll retain the just under 5db difference, just at lower levels.

Before anyone else tries to confuse the issue any further. I'm assuming for the sake of simplicity that we are using the same speaker, that speaker can handle the power adequately and that the same eq is applied to the signal. I'm also assuming that we have turned up the volume control to the point where the same level of distortion (let's say to DIN 45-500 here so 1%dist and the amp is running for 10mins and the temperature has stabilised) All of those things are implicit in my post which would have been far too long otherwise, as well as not being very helpful. OK which 'expert' thinks the 300W(EIA, IEC,DIN) would not be louder by 4.77dB than the 100W(EIA,IEC,DIN) amp. I'm surprised some people don't know how to calculate that themselves Level in dB: L = 10 × log (power ratio)

That's why I specified the same speaker.

Not wanting to get dragged off the point here but wherever there is a difference between perceived volume and actual volume there is a technical reason for the difference, that's the reason I keep posting to try and explain the technical side. I simplify things a little sometimes but in this case I specifically said through the same speakers, so same efficiency and same frequency response. In which case the same loudness. Valves are a special case, they compress the signal at high levels. If you used the same amount of artificial compression you could get the same sound levels out of a SS amp. I love the sound of a valve amp, they sound magic but there isn't magic inside, just engineering. People do, and should, buy amps and rigs based on sound alone. In the end that's the only important thing but some people are curious about the technical side of things and it can help you home in on what you are seeking having a little knowledge. I don't think anything you said was wrong but the statement you quoted is correct. A 300W valve amp will be louder through the same speaker as a 100W valve amp.