Phil Starr

Yes that's right I assumed 40l, speaker ports and any bracing

Couldn't resist it I've modelled your cab tuned to 55Hz and compared to my 30l cab It will give you just over 2dB more bass from 100hz down to 40hz (fundamental of bottom E). That extra box volume will give you noticeably more bass in other words, at the cost of a little power handling but power handling is still good, there's a dip to 300W at 90Hz and it handles 180w at bottom E which is pretty good, way better than the Eminence you started looking at. In practice you don't get a lot of fundamental from the pickups so unless you start using stupid power and an octaver you won't have problems at all in any normal use. There's still a bit of extra 'punch' at 120Hz but it's not a bad frequency response at all. Use one port of 110mm (plastic waste pipe) 15.5cm long or two 64mm (guttering downpipe) vents at 11.2 cm long. (or 3 at 19.2cm) You'll get a little wind noise at full power but you probably won't notice it in practice.

The best thing you can do is to download Winisd. It does all the calculations for you and will calculate the best sized box to give you the deepest, flattest response the speaker can cope with. Then you can change the box size and see on the graphs what that does to the frequency response, It'll calculate the port sizes too and everything else you can imagine about the low frequency performance too and you'll learn loads about speaker design in the process. You'll have to put the technical specs of your speaker in manually though, once you've done that the rest is easy. If that is too much for you one of us will calculate a suitable port size for you, probably using winisd.

Good Luck with this, I'm sure you'll get plenty of help from people here.

Because they are looking for simple answers. It's undoubtedly true that some of the difference in what we hear comes from the skill of the bassist. It is equally true that lot's of other factors are important, like the diameter of the speaker cone or the size of the cab. Sometimes those differences are significant, sometimes trivial. Few of us have the time or inclination to calculate all the factors in so as a species we grasp for simple answers and quick decisions. If they have a heavy old 4x10 they will swap it for a lightweight neo loaded 12 and if they don't like it conclude it's all down to being neo and then eliminate neo from their purchasing calculations from then on. I cringe when I see interviewers asking politicians "well minister is it ***********, yes or no." Their viewers may want simple answers but running the health service or education is rarely anything like as simple as speaker design. It's lazy reporting and ultimately people end up voting for politicians that offer simple answers like Trump, Putin or dare one say Hitler. Beware anyone who says it's all down to any one thing. Whether they say 'speaker cone size makes no difference to tone' or 'all 15's have a sound and all 10's a different one' they will be wrong. Sweeping generalisations are rarely correct. Neo magnets weight for weight are stronger, that much is true. It let's you do different things if you are building a drive unit but it can also let you do the same things if you choose.

well done

I'm doing this remembering repairing kit back in the very early 70's, well 1970 actually. My memory may be a bit iffy at that distance. Compression is something valve amps do naturally partly down to the valves themselves but also due to the saturation of the output transformer. Basically they just peter out as the output rises giving a nice soft sounding distortion as they over loaded. Guitarists used this to create all the sounds of early rock music. Combined with the feedback you get at ridiculously high levels it also gave them a lot of sustain to play with. Everyone forgets that most of these amps were pretty unreliable and a band running four valve amps on stage plus often valve PA amps was experiencing a lot of technical failures. Plus back problems from carrying the amps. Having 20 KT88's on stage was a nightmare to be honest. Transistor amps were coming in by then WEM (not much more reliable) and later HH for PA followed by early guitar and bass versions. They were certainly cheaper and quickly became more reliable but transistor amps really distort unpleasantly when overloaded so we looked for a way of getting that gentle overload that the old amps gave. Compression was what was needed so compression on instrument amps started as an effect to give 'valve sound' The first compressors I encountered used ordinary car bulbs to compress the sound. At high power they get hot and their resistance goes up, put the signal through a bulb pick it up with a photocell and bingo, compression. The next stage was a voltage controlled amplifier. Take the output and use it to control the volume or gain of the amp and you get compression. These were often adapted from tape recorder automatic volume circuits and used FET's as the controlling element. By about 1974 integrated circuits took over thousands of components in a single package. You could get undistorted compression at will but you wouldn't do that complexity with valves. So you wouldn't simulate valve sound with valves for obvious reasons. They still make optical compressors as an effect but with VCA's you can get completely controllable compression which is largely done digitally nowadays anyway. Valve based computer anyone? If anyone is interested https://www.soundonsound.com/sound-advice/q-what-optical-compression

Yeah that lead will put the two cabs in series which is important as it keeps your amp safe. you'll get some extra efficiency by using two speakers but cancelled a loss of power into 8ohms. Assuming the speakers are identical you get double the power handling using that lead and excursion of the cones is reduced so your bass may be less distorted and the speakers are safer. If you use that lead with two 8ohm speakers you'll end up with the amp seeing a 16 ohm load so less power. What you could do is use that combination as an 8ohm speaker and then add in an extra 8ohm speaker in parallel through your amp's second speaker outlet. That'd give you full power from the amp, buckets of power handling and high efficiency. No guarantees on what it would sound like but worth a try?

no

I'd do a little more research before going ahead. All I can say from experience is that all the fenders I've liked best have been Nitro finished and all have had a slightly livelier sound than those with the heavier poly finishes. That may be coincidence but I was sceptical about how a thin layer of paint might affect something as heavy as a bass body or even that the type of wood would affect the sound, but bass bodies do vibrate a lot when you hit the strings and you can feel it as well as hear it. If the body is vibrating then some of that must feed back into the strings via the bridge. I don't suppose the effect is huge but I might contact a friendly luthier or one of the small boutique guitar builders the post in the build diaries and see what they say.

just work systematically and you'll find it. You'll need to remove the grille anyway to look at anything else so do that and see if the rattle goes away. then have a good look at the outside of the speaker cone. Look for any tears but also have a look at the dustcap in the middle and where the cone joins the corrugated surround. Check that all the fixings on the speaker are tight and it is pulled firmly against the baffle (front board). If the rattle is still there you'll need to remove the speaker and look inside, First check the wires inside aren't touching the cone, this is a common fault and you can usually fix it to something with cable ties to stop this happening, then look for anything loose onside the cab, check the speaker magnet which will pick up any loose screws etc. Then work your way round all the woodwork and fittings to check for anything amiss. Tapping things gently will often tell you if something is loose. It's unlikely to be anything serious or difficult to repair. Good Luck

Ultimately you've got to decide how much you are prepared to lose over things like this. The drummer is being a tit but you won't change him if he and the singer decide to stick together. Talk to the singer (who won't be happy about having a suggestion vetoed) about coming up with a solution, like having only a limited number of vetoes as suggested. People always say the band is a democracy but if it becomes obvious the singer won't challenge the drummer you know who is in charge. You've than got to decide if you are happy to go on in their band or to look elsewhere. This happened to me a few years back and their band are still gigging and I've spent a while in the wilderness. I'm not sure with hindsight that I'd make the same decision again. The compromise we tried was to each suggest up to three songs, in a five piece that was 15 songs. We then put them into a survey and ranked them 1-15 totalled their scores and played the three most popular songs. Songs pretty much only get through if most of the band put them in the top five and no-one puts them bottom. Our 'band leader' didn't often get anything through and sulked so it didn't end well, but the rest of the band liked it as a system. We used Smart S urvey to do the ranking so it was anonymous https://www.smartsurvey.co.uk/

Many thanks to Derreybass who tried out the cab I've pasted his review into the second post so people can read it without having to search pages of text. Here it is below too to save you checking back. "I borrowed Phil's quick build cab one Sunday afternoon as it turned out that he was practising at the venue I was to be playing in that evening with a worship band. Normally I play through a Barefaced Big Baby 2 and a Peavey Mini Mega 1000w amp. The hall in question is very lively accoustically and can very boomy and difficult at times to hear what is being played particularly on bass. Bearing in mind what Phil had in mind when he designed the cab I was quite intrigued as to how it would behave in the room in question. The Big Baby also has masses of low down response and massive volume when required. I started playing the first few numbers through my normal set up things were useable but a bit on the boomy side then I switched to Phil's cab for the final numbers it was quite noticeable how the sound was came through and was easier to hear as the small cab handled the mid range and higher bass without the muddiness. I think the design he set out to make worked very well and met the requirements he laid down. I did miss the real low down response of the Big Baby at times but it was easier to hear what was being played through Phil's cab in the very tricky conditions the hall presented. A couple of these small cabs would be very useable and a relatively cheap high quality set for any one. Highly recommended. Having seen him make it at the Bass Bash a quick answer as well. Well done Phil."

Hey Bill we'll have to agree to disagree on the appropriate way to use English. Actually that Eminence link is really quite a good place to start delving into Q if people are interested.

So to go back to the original question neo v's standard speakers the material the magnet is made of isn't the factor you should be looking at but the power of the magnet. Neodymium magnets are much stronger size for size than ceramic magnets. Simply that means that you can make a very small (and therefore light) magnet out of Neo or you can make it bigger and get a more powerful magnet. You can do this with ceramic magnets too but a really powerful ceramic magnet can end up weighing more than the cab and then you need to beef up the speaker chassis which also becomes heavier and bulkier until you end up with something which is pretty much impractical for portable sound. Basically you come to a point where Neo makes more sense. So Neo magnets are just stronger size for size than ceramic magnets. You could just use that to make a lighter speaker but most of the time it's better to make the magnet a really powerful one. That extra power can be used to give you a bit more excursion like the Barefaced drivers, or it can give you better controlled (damped) low Q speakers or you could use it to make the speakers a little louder (more efficient). Usually designers do a little of all three. So technically it isn't the material that is important, you could make a Neo driver that would do exactly the same as a ceramic driver but if someone gives an engineer a better engine, well what do you expect them to do?

I'm not sure you read my post very well. You'll notice my first sentence says quite clearly that damping has other meanings.Yes I was very obviously referring to Q in all it's guises (mainly Qtc as it happens) but this wasn't written for anyone who already has that knowledge and I deliberately steered away from any technical terms or any algebra which probably isn't appropriate in this forum. My aim was to simplify things enough so that anyone can get a grasp on what is going on inside any cab they buy or decide to modify. I suspect you knew exactly what Ashdown meant by tighter. I know Kevin is an intelligent guy who likes to experiment and he asked a reasonable question whose answer would interest quite a few people. That's why I jumped in with an attempt at a simple explanation I hope people can follow. (For those who are confused by this Qes is the damping due to the magnet and coil, Qms is the mechanical damping of the speaker and Qts is the overall damping of the drive unit which combines the two. Qtc is the damping of the speaker plus the damping of the speaker cab, if you get that far it's time to look elsewhere but for simplicity there are lots of 'dampings' or Q's that control the movement of the cone but the biggies are the magnet and the cab design)

That's my theory too. Damping is a difficult term because it is both an engineering concept with a very precise meaning and a perfectly good English word with more than one meaning. Keeping it simple as far as bassists are concerned damping is about how much the cone flaps around when you apply a signal. If it moves too much you get woolly sounding bass and a peak in the bass output with the speaker giving up with really low frequencies. If it moves too little because it is over-damped then the cone is held too tightly and won't move enough resulting in a slow roll off in output as the frequencies get lower. There's a Goldilocks point where you get a flat response and the deepest bass that speaker is capable of. The damping comes from two important sources, the air in the cabinet and the strength of the magnetic fields on the bit of coil inside the magnet. Strong magnets make for lots of damping and need smaller cabs. Finding the Goldilocks point is what all the maths (or the speaker design software) does for you. Swapping the speakers into the 'wrong' sized cabs will change the damping and the bass sound. I think what Ashdown are saying about the Sica's being tighter is that the damping will be greater, so more deep bass, less distorted but without the artificial warmth of the weaker Ceramic drivers. Of course damping might tell you the temperature of the porridge but some people like it hot and others colder so you can't please every Goldilocks with the same design solution

You'll find two of these enough for most venues and one is good enough for the smaller pubs. A pair of the 50l cabs work well outdoors where the decent bass output helps with the losses you get from not having any wall reinforcement. Anything above that level and you and the drums will be miked up so no problems with the larger festival type events. I've yet to gig the smaller cabs so nothing to report as yet from direct experience. If you are based in the West Country you could always come and try them.

That sounds so familiar. There's not many clubs I'd willingly go back to.

Hi Johnny, I'm asking this just to check you are making the best decision for your needs. Would you be better off with the original mark 1 design, a 50l cab? It was specifically designed to be used with a 19" rack mount amp with no overhang and it will give you more bass than this mini speaker. The technique for building remains the same and you can build two 50l cabs out of a single 8'x4' sheet of ply. I have been gigging two of those stacked horizontally with a full sized Hartke 3500 for a couple of years before I moved on to my MB Tube 500. The Hartke was the amp I designed them to go with. You'll get some overhang with some amps even with these two minis placed on their sides not with the bigger speakers. The only reason I went for the smaller cab is that I play in some difficult spaces where too much bass is more of a problem than too little. The fact that you use a full size and weight amp suggests that full size speakers might be your thing. Even the 50l (14kg) cabs are a single handed lift for me, so they aren't exactly huge. The only problem with placing the speakers horizontally is that they are quite small and the top one will only be at waist height. There's no problems for the audience who will hear them properly but if you are closer to them you may miss out on some of the upper frequencies. bigger cabs get a bit higher and closer to your ears. As to the positioning on the baffle, it is better if the speakers are off centre as that reduces some of the resonances, however with a very small cab there isn't a lot of movement you can achieve and still fit everything in. So. the worst place for the speaker is plumb dead centre but sometimes it's the only practical solution. The positioning of the ports is less critical. So long as they don't get too close to the sides anywhere will do you can mount them in the rear panel if you prefer. This is the link to the original design thread, I've copied the dimensions into the first post so you can see them more easily

I think it's as simple as knowing the population size, the more people the more they need entertainment and the arts. the bigger the market the greater the opportunities. Every now and then there's a lucky coincidence of great musicians that come together and a 'scene' arises in one town. London and Liverpool in the early 60's, Coventry in the late 70's Manchester in the 80's but you can't really plan for that. No-one has mentioned Bristol yet so I will, lively musically with a bit of an alternative feel. good Luck

I've no doubts that a frontman/woman is better if they are concentrating on the audience than looking down but in the end the most important thing is that everyone is enjoying themselves. Most bands aren't full time professionals so expecting some sort of ideal isn't really sensible. Having the singer going to the wrong part of the song or breaking time when they mess up is pretty disruptive so it all comes down to compromise. iPads are less obtrusive and I'm seeing them more and more, do it if you have to I guess.

I don't think there's a strict line Les and open mic's and jam sessions are as varied as the musicians that go there. My experience is that each feels different and both are often mis-described. The minimum requirement for an open mic is just that, a mic and a small PA. Most of them just have acoustic acts and sometimes even comedians and poetry readings, a few are essentially folk venues, it's worth checking. The minimum for a jam session is that at some point a few people will get together and play. Jamming in the sense of playing a completely unprepared 'standard' with musicians jumping in and out, and improvising seems fairly rare. You'd normally expect jam sessions to be electric, have some sort of back line provided and a drum kit, but that varies. How cliquey they are depends upon the host and to an extent upon the landlord/lady. Many bands use it as an excuse for practice in public and the standard can be quite good, because they are used to playing together. They'll often welcome other acts as this gives them a break and of course over time the musicians all get to know each other and the songs a good host will notice anyone walking in with an instrument and try to include them once they know what they do but it is like trying to break into any conversation between friends, tricky to get started. Open mic's tend to be a bit more open, the host will have a rough idea of how many performers they have and divide the time fairly between them, but they will also know who amongst their regulars will be good and who will clear the bar so some people may get more than others. If anything is billed as an open mic it is worth always taking some sort of amp as a bassist, preferably a smallish combo as the PA may not be up to handling bass. The venue may affect how open the event is, the host is usually paid or gets a portion of the bar takings, if the manager wants to entertain his or her regulars then they are going to expect the host to keep the standard of music up so 'better' acts are going to get more time.

No news of the review yet, I've messaged Derreybass but still waiting for a response, he's not on here that often.

Right, you're still trying it out, good idea. 12" speakers only handle around 300w whatever they say about 1000W amplifiers but EV's are good and you have the subs so all in all the PA should be louder than the RM's, certainly a match. The RM's sounded to me like they have a mid bias which makes them pretty punchy, that's if they were the same ones that we tried out at the bass bash a few weeks back. (Thanks Ashdown). We were very impressed with the RM's at the price, and that voicing works really well in difficult rooms. Maybe that is what you are missing. You ought to be able to get something similar back using the Ashdown graphic. I'd start with the 30Hz right down and a touch of boost at 100Hz then maybe tweak the mids a little.