Phil Starr

I also have the IPR1600, I bought a second so I must have been happy. One speaker per channel is best there's even a built in crossover to a sub built in so you could try that as an experiment although probably not an important option. Reliable and absurdly light. Even with the IPR 1600 you might end up driving the 1x15 too hard so listen out for any unusual noises and turn down. How powerful is your ABM? You really ought to be able to out-muscle any drummer with those two cabs. The PA amp will give you a much cleaner sound though. If the festival is open air you'll still need PA support.

This is a good demonstration of off axis response and distance problems http://www.youtube.com/watch?v=MvUfXxalD7Q

[quote name='geoffbyrne' timestamp='1396177635' post='2410602'] Would a bit of compression allow you to turn her up a bit? G. [/quote] No, compression brings up the feedback and makes things worse. If you think about it guitarists use feedback to improve their sustain.

Good luck with the mic technique, our singer bought a top of the range Shure KSM9 to solve the problems. Sounds wonderful but at a gig, after a couple of rums for courage, she was holding the mic at arms length and complaining that she couldn't hear herself through the monitors. When I suggested, probably fairly forcefully that she might like to hold it up to her mouth she informed me that she shouldn't need to with a £500 mic. It's not uncommon for the non-techie to resent the laws of physics, there's a lovely scene in Zen and The Art Of Motorcycle Maintenance where two people fall out over the thought of using a piece of coke tin as a shim rather than buying a specially imported German shim. The best bet might be to get her to watch videos female singers who really use good mic technique. The 45degree thing is usually copying the pose off some pop video which looks cool but is just someone miming. Hope she never reads this. I love her dearly but she drove me nuts.

Hi, we had the same problem for years, our singer had a great voice but quiet and no mic technique. Your problem is gain before feedback, your mixer will probably let her be loud enough but you'l get howlround before you run out of gain. Adding a pre amp won't help that. First of all the SM58 isn't the best for avoiding feedback, it was great in 1962 but we can do better now. It is a cardioid and a super or hyper cardioid has a tighter pick up pattern and will reject feedback better. Audix OM5 would be better as would several by AKG, Electrovoice, Sennheiser, The other thing to look at is mic technique, pointing the mic straight at the back of her mouth and holding it right up to her lips would raise the level of her voice compared to the racket the rest of the band are making and reduce the gain needed to get her loud enough. Trouble is many singers find this intimidating if they lack confidence.

Enjoy

Who is it that can't hear the bass? I gig regularly with a 2x10, nothing particularly special either in terms of efficiency. I can be louder than the drummer and I don't need any more than that unless I'm playing outdoors. Your guitarists should probably try and find their volume controls, they don't have to play on 11. It's possible that everyone else can hear the bass perfectly and at the right volume, You may not because a 2x10 isn't very high and is probably pointing at your knees or thereabouts. you hear better with your ears By all means take the extra cab, you'll get the benefit of raising one of your cabs to ear level so you will hear yourself much more clearly than currently. Or you could tilt your cab. I'd probably go for the extra 2x10 with all the speakers in a vertical line but if you have all three cabs you could try both combinations.

Hi Rich, Bill is of course quite right. In many ways though this is something you could do in the privacy of your own home but not something to do in public If each of the oddments of speakers you are adding can handle the voltage swing and hence the power of the amp then the speakers should come to no harm. If the overall impedance is above the minimum allowed for your amp then the amp shouldn't be damaged. The question is however, why would you do this? Other than curiosity of course. Amps may power into very low impedances without immediately blowing the amp but they usually run hot and the power available reduces as they run hotter, many designs will be less reliable if you are running them at full power into low impedance and the internal resistance of the amp and more significantly the leads will reduce damping and may introduce audible distortion. You can engineer around all these problems as an amp or system designer but it's an expensive option for a bass stack. There's a reason most systems settle on 4ohms as a good compromise. Mixing speakers is more complex than just impedance and power handling. If one speaker is significantly less loud than another then you won't hear very much of it and there is little point it being there so adding a 16ohm speaker to a 4ohm one of similar sensitivity (per watt) won't add very much to the sound. It would be similarly pointless to add a 92dB/w speaker to a 102dB/W speaker for the same reason. Adding any extra speakers will have a negative effect on the off axis response and mixing speakers of different types will have slightly unpredictable effects on frequency response, often losing the character of both speakers. If you were engineering your perfect bass speaker then you wouldn't go about it by mixing impedances, you'd start with a driver that sounded the way you wanted, if you need more sound then you'd try to make it louder by using a bigger motor and better suspension or by adding more, identical speakers. If I can use an analogy mixing speakers like this is a bit like a formula one team deciding the way to win a race is by bolting a sports car onto their race car for a bit more power. Having said that if you have a room full of speakers trying them in every combination possible sounds like a good evening's entertainment to a nerd like me

Use a heat gun with a variable heat setting like the DeWalt and you won't scorch anything, it takes a little longet with the heat right down. If you use a new scraper then file the corners into a smooth round as it is these bits that score the wood. Plasterers use this trick on their trowels. If you are going to finish with a solid Candy Apple colour then it wont matter too much you can fill any dings, if you intend using a translucent colour then be more careful.

Hi Balcro, great job mate. restricting the port area looked good to me too but I haven't had time to run the modelling. I agree with Bill about the Eminence box sizes and marketing. A lot of their extensive range of speakers look like cut and shut jobs to me. A kit of off the shelf parts which are bolted together to make a new model. The T/S parameters of some of them are often a bit odd anyway and won't fit easily into any sensible cabinet. Many of them have Qts quite high and aren't really very suitable for ported cabs of a practical size, which would make them less saleable. Put them in a smaller cabinet and they'll work, at the expense of rolling off at a relatively high frequency and an upper bass hump in the frequency response.

result!

As I think everyone is telling you the DI should have worked. Check it out with your mixer at the next practice. If it takes a battery try it with one. It could be your leads, the DI may be broken, The PSU may be dead, the gain on the mixer might have been right down or the mute switch on/ routing set to the wrong channel etc depending upon the complexity of your mixer. You really have to try out your backup without the pressure on, it's hard to concentrate in a gig disaster situation. At a pinch most mixers have enough gain to take the lead from a guitar/bass directly if the jack input doesn't work use a jack-XLR lead and plug into the mic inputs. I carry a little mixer amp as a spare, at a pinch it'll double as an instrument amp, run the monitors or even the vocals through the PA so it covers the breakdown of all the amps and the mixer, if the speakers go I'd be able to turn the monitors round and we'd be able to finish the gig after a fashion. So far it's never been needed.

I can't tell an Eb form an E at the best of times All of the above really. the room acoustics and echos/reflections are phase issues. My favourite set up is with the bass bins providing all the deep stuff to the audience (enough comes back to me anyway as they are effectively omnidirectional at these frequencies) and a little Hartke kickback providing my monitoring, with the bass rolled right off on stage. the trouble is the rest of the band, particularly the drummer, prefer a lot of bass on stage for the excitement value. I've given in and gone back to a traditional stack but end up with a real sonic mush in some venues, low ceilings seem to be the biggest culprits. Looks like we've all been there.

It may just be a pre amp, the power amp with the separate mains switch and blank panel might be a later add on. If you like the sound does that matter?

Well the two eights are just about the same area as a 12" driver. It's possible with a single 12 to create 120dB @ 1m which is roughly as loud as a drummer so it is also possible that these two eights will produce the same level. The manufacturers claims are all about maintaining the 'sound' of bigger cabs. Again technically this is not a problem my 5" hi fi drivers have no problem reproducing the 32' pipe organ sounds on some of my records, far lower than anything a bass will do. The problem is in doing loud and deep with small speakers. It's just about possible with a single 12 or 2x8 so you'd need to check it out, they have one in Mansons in Exeter if you can get down there. Listening to the sound on the website they sound pretty good but I would say characterised by an open top end rather than deep bass, which is much as you would expect from 8" speakers. the only way to resolve this is by listening.

Water based will penetrate too, actually I think it's a mixture of water and alcohol but I don't suppose that is important.. I'm guessing at the finish you are after but it sounds as if you want something like a 'limed' effect but black not white. Lime is applied as a paste and because it is made of particles not dissolved pigment it won't penetrate but sit on the surface and in the grain. Then if you sand back it exposes the wood but leaves the white in the grain. Nowadays people use liming wax or even eggshell paint to achieve the effect. http://voices.yahoo.com/how-create-aged-effect-liming-wood-2549318.html You might be able to do this with black paint.

I'd be pretty careful about this, Spirit based wood dyes penetrate a long way into timber and Ash is quite porous, you won't be able to sand it out. Practice on some scraps of ash first. If you don't have any Yandles have big boxes full of off-cuts which they might post to you http://www.yandles.co.uk/ .

To be fair it is also a nonsense as a design. Given that the distances between the speakers radiating surfaces is in the 10-70cm range and the angles less than 30[size=4] degrees, where off axis response is only going to be a few dB down it will pretty much have all the comb filtering problems of a 4x12 over the midrange. Only very high frequencies (high for a bass anyway) are likely to be directed towards the bassists ears. [/size]

Big apology to all those following this, I've joined a new band and have new set list to learn and bass playing is what it is all about. My aim was to summarise about a weeks worth of discussion per post but I'll have to condense that a little to catch up. When I left it we were starting to look for a good driver (the actual speaker) for our cab. I won't pretend it was an unbiased search. Stevie was keen we look outside the usual suspect (Eminence) I had previously done the search and bought a couple of Beymas. Celestion and Faital were mentioned early on. Technically we had some design specs to meet. We decided it was practical to make a single 12 capable of matching a drummer which meant achieving 120dB @ 1m within its maximum power. Most 12" speakers handle around 300W so that means something like 95dB/W efficiency. We also decided a practical 1x12" needed to be pretty portable so a speaker capable of working in a box no bigger than around the 60l mark was needed. We also had a bias for something which would handle low frequencies without overloading too easily, this means looking at the excursion or Xmax and anything with an excursion below 4mm was out. Then we considered frequency response. We discussed the bass characteristics a little. The choice is really between an under damped speaker which characteristically gives a bass peak at around 100-120Hz of a few dB and rolls off quickly below that or a well damped speaker with a bigger magnet and more control which would give a smoother response and a respectable output down to 40Hz ish. We didn't consider an over damped speaker which roll off gently from above 100Hz but can give good tight bass and acceptable responses if you apply a little eq. Damping is measured in the Q of a speaker and overall Q or Qts needs to be about 0.4, anything above 0.5 is underdamped and likely to give a bass hump in a practical cab anything below 0.3 is likely to be very tight and lack bass output. We decided to go for a modern controlled bass response so we looked for speakers with a Q between 0.3 and 0.5. if we wanted to look for an 'old school' sound we would have looked for something with a Q somewhat higher 0.5-0.6. It's too easy to get a bit anal about bass response. It's the only bit you can really control as a cab designer and we are all bass players, but most of what we hear from a bass is actually mids and the higher frequencies are much more important in defining the 'sound' of a cab. We wanted a single speaker to cover the whole range for our first cab it would need to go up to at least 3500Hz and preferably higher. 12" speakers naturally cut off at about 1100Hz and response above this is down to the cone flexing so the sound comes mainly from the middle of the cone. A lot of speakers actually give a big increase in output at breakup so you get a peak in output from 1-3000Hz another contributor to the 'old school' sound. More about this later, probably. So the 'ideal' driver would specify Fs 40Hz Qts 0.3-0.5 Xmax >4mm 96dB/W frequency response 40-4000Hz +/- 6dB We modelled all of these and probably some more Beyma SM212, Celestion BL12-200x and BN300X, Faital PR300,Fane Soveriegn 12-300, Eminence Deltalite 2512, 3012HO, 3012LF, Beta12-II. more soon, I have to practice

The Monacor is designed to crossover at 5kHz so you couldn't use it with the 3012lf unless you wanted a hole in the response. I'm not a puritan about thin walled cabs by the way, I can see advantages with a rigid cab but the weight advantage isn't all it's cracked up to be. Alex Claber has stated that weight saving isn't his main reason for building cabs that way. What I'm sceptical about is that the difference between a well made lightly braced conventional cab and an equally well made thinner walled and heavily braced cab is that apparent in a gig situation. Since the weight saving is minimal and the complexity of build greatly increased I question how far it is worth it. A reasonably well braced 12mm cab might be worth thinking about too. One day I'l get round to building two cabs and do some A/B testing. Incidentally I have a 15" Deltalite in a 3/4" cab and the total weight is only 18kg, your cab will be smaller and lighter. Having modeled the 3012HO as part of our design process I think it would make a great cab on its own, though a single one in a West Country pub might well let the higher frequencies bypass you, two together would probably be OK. The sound is going to be very different from the Jacks even though you are using the same speakers, because of their design the Jacks have a 10dB difference in levels between the horn output at 300Hz and the reflex output at 100Hz and this colours the sound. the reflexes won't be as loud but the bass is going to be the same as the mids so the balance will sound deeper subjectively. One thing occurs to me, you really aren't too far away. We are looking for a 3012 to trial as part of our design, if you came up to Somerset for the day anytime it would be simple enough to clamp one of your speakers into a cab and for you to try it, if the sound is one you like the dicision is made. Ideally we'd like to run some tests at the time but this could be fairly flexible. I've got a couple of 50l cabs here.

If something looks too good to be true it usually is. Having said that the magnet is a decent size and the Chinese are banging out so many speakers for other people that it wouldn't be surprising if something half decent didn't find it's way here. there are three potential shortcomings, the first is that the speakers don't meet their specs. The power handling is probably right given modern glues and a 2.5" coil. Sensitivity is quite high for a cheapie but could be possible with a 50oz magnet. What you can't get is an average magnet high sensitivity and lots of deep bass. Have a look at the Eminence delta [url="http://www.eminence.com/pdf/Delta_12A.pdf"]http://www.eminence....f/Delta_12A.pdf[/url] with a similar magnet and coil and you'll see that the sensitivity is similar but the resonant frequency is much higher at 55Hz. To get this sensitivity at this frequency I suspect the excursion has been reduced and this speaker will overload or compress at relatively modest levels. If you are lucky it will sound OK at low levels but overload at noisy rehearsals depending upon what sort of music you play. Depends upon price really, you can get an Eminence beta12A II for about £50 which would probably be at least as good and has all the parameters available or you could pick up a used cab for under £100, but this might be a cheap way of dipping your toes into self building. It probably will beat your car sub hands down.

Hi Rich, there's a lot of questions there I'll try and deal with the woodworking ones first. If you do go for a 50-60l cab then it is quite small and you don't have much flexibility with shape. For example with a 30cm driver and a 10cm horn plus enough wood left to be strong enough to fix to you have a 50cm high cab and you want it 40cm wide. this means that for a 60l cab it will only be 30cm deep. This compromises the port as it can only really be 20cm long or it gets too close to the rear panel. If you want to tune deep then you need to restrict the port width or bend the port which introduces more problems. If you use a narrow port it doesn't need to be so long but can suffer wind noises at high levels. If you use a deeper cab you end up with a square front and an almost cubical cab where all the panels resonate at the same frequency. In practice you will come back to the 30x40x50 shape or thereabouts. Now the horn/tweeter. Firstly there are no decent piezo tweeters in reality, I've tried quite a range over the years and they do a job but with limited success. The old Motorola's which most of the currently available ones base their designs on were as good as anything the current Chinese mass produced ones are fairly poor and production in Europe and the States has ceased as far as I know. They'll colour in a bit of high end fizz and that's it really. 9mm ply really is very flimsy for making a high powered cabinet, The only way to stop it resonating and transmitting sound is to use extensive bracing. The bracing could easily end up weighing the same as the rest of the cabinet and adds a lot to the complexity of building the cab. I know it is very trendy in these pages to go for rigid, lightweight designs but it takes a lot of development to get it right, it may make sense for commercial builders with CNC routers and design budgets but don't knock the intrinsic properties of 3/4" ply. Secondly, why do you want a horn? Most of the stuff you want to hear from a bass ends at 4-5000Hz. A lot of horns don't cut in until this level, so are irrelevant to the sound, all they'll add in is string noise. If you want a real 'hi fi' accurate sound then you want something that covers the 1-5kHz range. Something like a PA horn. I sometimes use my PA speakers for bass and it does sound nice, The horns in these crossover at 1.6kHz. If I wanted a cleaner bass sound designed in I'd probably go for a 6" driver or smaller to provide the 1-5kHz range. If I was designing with a wide frequency horn or a mid range driver like this in mind I probably would go for a 'proper' LF driver but the 3012HO is a capable driver and as you have them I'd definitely try them first.

Hi, how soon do you intend building this? We are working on a design for a 50l cab which will match this driver, slightly derailed because I joined a new band and have 25 new songs to learn. This will be a free design for anyone to copy. The 3012HO is an excellent driver. http://basschat.co.uk/topic/227904-1x12-cab-design-diary/ You might find this interesting too http://basschat.co.uk/topic/200152-1x12-diy-cab-build/ If you go onto the eminence site you will see that the large cab has worse power handling than the more compact cab and they recommend using it with reduced power. This is a feature of all reflex designs not of this particular speaker. I really wouldn't go any bigger than about 70l nd we ended up going for 50l as a good compromise.

You don't need to worry about class D, just like the 'old' amps there are some that are oversold with 'car stereo watts' but there is no inherent reason why they shouldn't meet the specs or deliver every advantage they promise. Most of the weight saving is in the power supply which works the same way as the one in the computer you are reading this on, and they work. I'd always say there is no need to be louder than the drummer. if they need to mic up the drummer you can DI into the same PA the drums are going through. Money no object and I'd go for the AER Amp One, it's not stunningly light for its size but it is tiny and it delivers unbelievable sound. It looks like a practice amp but it'll more than match the beefiest percussionist. I'd say it's one you need to try if you can afford that much, if it is for you then you know you have the best solution on the market. If that style isn't for you then go for some of the options above and doubtless yet to come, Has anyone said Barefaced yet? The other option for someone who likes clean is to go for a powered stage monitor or PA speaker. The best ones can handle bass no problem and will be designed for a flat sound from the off. Just a thought.

I'm afraid that in oversimplifying some of the advice is a bit misleading. I'll summarise but you can get more detail here http://www.ultimate-guitar.com/columns/gear_maintenance/making_it_loud.html Most of the power from your amp is wasted as heat, only about 5% ends up as sound. The amount wasted varies from speaker to speaker. this is reflected in the efficiency of the speaker usually given as how loud it is for just one Watt or dB/W Some bass speakers give just 92dB/W and the best in terms of efficiency maybe 102dB. Every time you increase the power by 10 you get an extra 10dB and you need about 120dB to match a drummer. That's about 70W through the loudest speaker and 700W through the quietest. As said 300W through an average speaker will be enough. Size matters but only a bit. A big speaker will be louder than a small speaker if everything else is the same and doubling speakers up gives the same advantage in sound levels as having a big speaker, it's the cone area that counts. However lots of other things like how powerful the speaker magnet is will count too. It's possible for a 12" speaker to be loud enough on its own if it is capable of moving far enough and has a powerful magnet and many 15's will do it on their own too. If you are using a 100W+ amp in a rehearsal the usual reason for not hearing is that you are standing too close to your amp and it is pointing at your ankles not your ears. Tipping it back and pointing it at your ears will help a lot. Hope this helps