Phil Starr

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.

At the risk of stirring up another hornets nest I'd like another go at this. I don't think it's difficult to understand and it's a helpful concept. The first thing to say is that watts are real and that they do matter. An amp with more watts will ultimately be louder than one with fewer watts through any given speaker. If you want it louder then you can increase the watts, or improve the speaker or a bit of both. If you are buying an amp (a head rather than a combo) then the wattage is one of the things you should know. One of many, but one of the big ones. Watts can be measured (this is Wikipedia) 'The watt (symbol: W) is a unit of power. In the International System of Units (SI) it is defined as a derived unit of 1 joule per second,[1] and is used to quantify the rate of energy transfer.' So long as you all stick to the same system of measurement then it's a simple measurement and most secondary school students could do it. You can convert watts into any other measurement of power, so 745W is one horsepower. (That's brilliant, my Mark Bass Tube is 0.67hp, should all valve amps be rated in horsepower or British thermal units ) That's where the rms measurement comes from. if you have a direct current running a motor or a heater than measuring the power is simple if you know the current or the voltage and the resistance. When someone had the bright idea of using an amp to control a motor then you need a way of converting. The average voltage of an amps output is zero as it goes up and down with the waveform, but mathematically if you square the voltage then all the minus's become plus's and you can work out the average or mean. Then if you find the square root of the that average you can compare ac watts and dc watts. Its the root of the mean of the square... RMS. Of course if you just use the amp to heat an 8ohm resistor it will do the same thing, you can compare the energy being transferred, just less accurately. In the start of amp design that's how it was done. All controlled by engineers you see, honest, measurable, repeatable. then the ad men got involved. To be fair the engineering method could reasonably be said to be over-doing things for music. Music has loud bits and quiet bits, bits where the amp isn't making heat into 8ohms and the amp can cool down. That means you can make an amp with less cooling built in and use a smaller power supply saving weight and cost. It makes engineering sense to use an amp that can make it's power for a limited duty cycle, say 20% of the time. That's where the confusion comes in you have to have a standard that everyone agrees on or people cheat. Rms all the time, 20% of the time or just for 0.01 of a second at a time? In Europe the DIN 45-500 standard held sway for a long while it is basically an rms rating which the amp has to produce for 10 minutes with a pink noise signal filtered to contain a similar spectrum of energy to real music. EIA RS-426 and IEC 268 used outside Europe are broadly similar. It's a fair test for audio amps and it ought to be used. Behringer used to give rms ratings based on IEC/EIA measurements. It's a bit like cars and their fuel consumption figures. You probably won't get the consumption they advertise and some will be closer than others depending upon the detailed design of the car but it's a good start and cars with similar figures will give broadly similar performance. You know the test isn't perfect but that it is fair and good enough to be a big help when choosing what to buy. When somebody like Volkswagen cheat eventually they get caught and everyone knows they are cheats, people lose their jobs and fines and compensation come into play. The same with food standards. Why should consumer electronics be any different?

Sennheiser HD201's cheap as chips 3m lead sound great with bass Mine are about 5 years old and are still going strong

I suspect they'll be 8ohm speakers, the 4x10 in the Hydrive series is an 8ohm cab and the 2x10 a 4ohm cab. If that's right then your 4x10 will be 8ohms and you can either wire your 2x10 as 4ohms or as 16.

If this is the current version with the neo drivers then you should have no problems. a quick look at the manual shows the cab is in fact 4 2x10 cabs internally and a sealed cab so essentially you could just build a 2x10 the same volume as 1/4 of the cab you have and you'd get the same sort of sound but quieter and without the horn. Or a half sized 4x10, with or without horn. If you use the horn you may need to tweak the crossover but someone here may be able to help you with that. I'd probably go for a 2x10 with the horn in and another with no horn. That way you can take one cab to most gigs or both if you want a bit more oomph. If these are the neo drivers you can probably sell the spare drivers for a decent price. Without knowing anything about the drivers specs it is possible you might be able to put them in a ported cab and get a bit more bass out of them, it would change the tonal balance but that might be a good thing. Reckon to spend about £50 on each 2x10 (a 4x10 is only going to cost about £20 extra as it's only the extra wood) by the time you've bought all the handles corners trim and so on. Then think what the 8x10 is worth and what you'd have to pay for a 4x10. If you decide to go ahead you can get a lot of help on this forum.

I'd absolutely go for those bars rather than the party light T-bars, I have both but the T-bars are cumbersome space guzzlers best used for blinding musicians and I only use them for lighting the audience nowadays, I have a 12 way 1metre strip which goes behind the drummer as an uplighter and some of the round PAR lights but I'm going to get a couple of those short bars for the speaker poles.

Win ISD will cope with two ports but assumes they are both the same length and size. I wouldn't want to have to do the calculations for two ports so completely different. Conventionally you'd treat two ports (or any number of ports) as if they were a single port with the same area as all of them combined. with a 55mm and 75mm port that equates to a 93mm port. Remember the volume of the cabinet is decreased by the ports and the volume of the speaker itself so this is probably a 30l cab in reality. The 75mm port is nearly twice the area of the 55mm port 44cm2 plays 24cm2 so you should have a noticeable improvement with just that change.

Stevie is right, that looks like a decent speaker, that's quite a big magnet compared with some OEM drivers. I think it unlikely you'd get a huge improvement in output just by swapping it, though you might get a tone you'd prefer, or not. I thought I'd answered this but maybe someone else asked a similar question. Since you are thinking of building another cab then one option would be to build a cab and try out a speaker by disconnecting the internal driver and plugging in the new one. That way you'd have your extension cab and would be able to compare it with the original Ashdown driver. Actually if you can find people with 1x12 8ohm cabs of around 37 litres you could even try those out without having to build anything. I'm currently using the Beyma SM212 in a 30litre cab successfully and modelled it in a 40 and 35 litre cab where it modelled well. so it might be a candidate. It may be that Ashdown could provide you with an 8 ohm driver if you tell them what you are trying to do, they are exceptionally helpful. The thing to realise however is how subjective our impression of sound is. A lot of what we perceive as bass is actually around the 100Hz area, deep bass is often a bit of an embarrassment on many stages, Heft? I'm really not sure what that means and suspect we all hear it differently. However changing drivers is going to change the upper range of your bass quite a lot too and you will hear those differences much more than any small changes in bass output. your difficulty will be in not knowing what the changes might be until it is too late and you've bought a speaker you aren't happy with. However having two drivers will really increase your efficiency and your maximum output, you'll be able to run your amp lower or decrease the distortion when you run at high levels, you'll be able to use a bit more bass boost if you need it, raise your speaker off the ground nearer your ears so there are lots of gains to be had potentially. An 8ohm combo with n extension speaker is a very sensible way to go. On the minus side what would you get if you sold the Ashdown, add in the cost of two 8ohm drivers and ask what you would/could buy with that sum. £200 plus the Ashdown might offer you more for your money with the chance of trying it before you buy.

The answer is in the price. Aluminium is a light metal but even so it's way denser than wood so you have to mould /cast /extrude it into shape then use fairly complex techniques to make that into a cab. The machinery to work wood is cheap and simple too It's not all positive either, you can achieve a reasonable rigidity easily enough but metal is less self damping than wood so it sets up it's own design challenges. There were some interesting hi fi designs in the 80's that used honeycomb aluminium but they were very expensive, as is the MB150. Basically there are marginal gains for a large cost and that money might be better spent on other parts of the cab/combo.