Phil Starr

You can overdo the worry about joints, rabbets make it easier to clamp up but don't add significantly to the strength, there isn't a big increase in glue area, there are lots of successful cabs with simple butt joints for example. My favourite for home construction is the reinforced butt joint with a 1" batten screwed and glued along all the joints. Screwing and gluing means no clamping increased strength and some damping of panel resonance and it is so easy. It was the recommended technique for years and even some commercial cabs used it when they were hand built. Almost any mastic is good for sealing joints, though if you do a good job should be unnecessary. The glue should seal everything. I use water based mastic because I don't like solvent fumes around expensive drivers but by all means use silicone if you leave the cab to air for a couple of days before fitting the driver permanently in place.

Depends upon how bad it is. My first bass (Cort) had a real problem with the D and G strings sounding really weak. New Rotosounds brought them back in but a month later they were lost again. Numerous internet searches and forum discussions revealed it to be a common problem but nothing suggested about set up or eq really did more than disguise the problem. It was solved when i bought a new bass, (MIA Jazz) the D and G are intrinsically punchier with everything from flats to Rotos and beyond. Eq the mids and tops and you get a nice balance. Same with my T-bird and P-bass. I swapped pickups on the Cort for Kent Armstrongs and that works well now, problem solved. If you are unhappy with this I doubt you'll tweak it out and I don't think it's the strings, though I'm sure some are better than others. Some basses and some pup's are good at this though.

If like me you are new to playing the blues there's a Hal Leonard book on blues bass which covers about a dozen blues standards, pretty much all the songs mentioned above. There's a play along CD too so you can make your mistakes in private. Most importantly it gives an explanation of 'from the five' or quick IV and the endless variations of the turnaround (last two bars). Most blues players kind of underplay how much knowledge they have, the music has a structure but infinite variations and if you've been playing it for years then you kind of forget having had to learn it. Don't undersell yourselves guys. Have fun

Thanks for this guys, I think I'll go for it. The AER will have to wait.

Thanks, I think from an earlier trawl that Doddy has the earlier MiBass with the semi parametric eq, since I use very little eq this shouldn't be a downer for my use.

If you are putting 500W into a single 15 unfiltered and probably with bass boost then there isn't really a speaker made that will cope long term. It says something good about the Peavey that it is still coping. Look inside and if it says Black Widow on the speaker it is a decent speaker. The Thumpinator is a great idea for a speaker abuser It removes the deep bass you can't really hear without affecting your sound much and you can crank further without damaging your speaker. It sounds like you need to get a second cab if this doesn't work. You are asking a lot of a cheap single 15. You can buy a second hand Peavey in a cab for £50-100. Less than the Kappa pro

I'm wondering about getting one of these as they are going cheap at the moment. I prefer an uncoloured sound. DI into the PA sounds fine to me but my bands prefer to have some bass on stage. Any one had any experiences with one of these?

[quote name='grenadilla' timestamp='1409178484' post='2537293'] I have a similar problem. I just bought a used Ashdown ABM 610 with one blown 'Blueline". I have found no replacements except Eminence Beta , Eminence Delta, or some newish BL 10-200X Celestion. I am leaning toward this 200w Celestion. The Ashdown speaker says "made in England 150 watts".This cabinet is sealed. Opinions or advice wanted... [/quote] Sealed cabs are much simpler and you are less likely to have a caastrophic result but mixing drivers in a cab isn't really going to be the best way of going ahead, internally they share the same air and externally they will 'share' the sound radiated and will probably make the cab sound a little blander or less characterful, although one speaker in six isn't going to make much difference.

[quote name='hogman' timestamp='1409162923' post='2537020'] I am currently having a veritable nightmare with my nemesis 2x10 and 1x15 cabs, there humble speakers dying, granted they have had a hard life. Got manufacturers replacement speakers that were both replaced by myself I am more than qualified to do this, I ran them in at low volume for 72 hours as I do with all my drivers. They have had very little hard use (compared to what they used to get I was gigging between 3 and 5 nights a week and out 4 - 5 a month now) and suffered no real abuse, I use an Ampeg SVT 3 and have since I bought the cabs. The speakers looked the same but are obviously not. Could you suggest a better quality speaker for the cabs (Eden Nemesis). To say I am disappointed is an understatement. The cabs have served me well for over about years ( being fed a diet from punk rock to Jazz and experimental playing) and I have replaced the 10's but not the 15 and was hoping to get a lot more out of them than 7 Months. Not to bothered about price n drivers is what I am after the cabs are a great size. The horns are a bit shouty. Any help would be ace! [/quote] You need to give us some help here, We need to know the internal volume of the cab or the internal measurements, if you know the thickness of the walls you can work it out from the external measurements or you can remove the speaker to get inside. We also need to know the size no and length of any ports.

Andertons have an offer on at the moment, the Mi12 is £199 [url="http://www.andertons.co.uk/bass-cabs/pid24233/cid686/ashdown-mibass-mi12-1x12-cab.asp"]http://www.andertons...12-1x12-cab.asp[/url] This might be the thread they are referring to [url="http://basschat.co.uk/topic/227904-1x12-cab-design-diary/"]http://basschat.co.u...b-design-diary/[/url] as usual it has drifted a little but there are enough details on there for you to go ahead and build one already and the final design will be ready soon, I promise [url="http://basschat.co.uk/topic/227904-1x12-cab-design-diary/"]http://basschat.co.u...b-design-diary/[/url] . If you ask on the thread I can put the dimensions back up. Someone ( 6V6) has already built a close 'version' of this [url="http://basschat.co.uk/topic/200152-1x12-diy-cab-build/page__hl__1x12"]http://basschat.co.u.../page__hl__1x12[/url] which will give you an independant view of how it might sound.

Well I never, I was going to challenge you on that one Stevie but I checked, Youngs modulus for steel is 210,000 v's 70,000 N mm-2 for aluminium depending upon which alloy you are talking about. So you are right. However of course rigidity and stiffness are not the same and cast aluminium structures are thicker for the same weight so aluminium chassis may be more rigid even if steel is stiffer. It is certainly true that all the bigger ceramic magnet speakers have had cast chassis for the extra rigidity for years. Bill is right though, I think, about heat dispersion for neo speakers, their light weight would not need particularly good load bearing but it is difficult to radiate heat from small structures with a relatively low surface area. [url="http://aluminium.matter.org.uk/content/html/eng/default.asp?catid=217&pageid=2144417130"]http://aluminium.mat...geid=2144417130[/url] [url="http://en.wikipedia.org/wiki/Young%27s_modulus"]http://en.wikipedia.org/wiki/Young's_modulus[/url]

Don't paint your cones, depending upon their make they will be made of carefully mixed plant fibres (markbass use a bit of banana fibre in the mix I think) possibly treated with a coating to damp resonances and adjusted for weight and stiffness. Adding paint will affect both the mass and stiffness and ultimately the sound of the speaker. I think the OP has decided changing the grille is better anyway but just in case anyone else is considering it.

Sorry but that isn't [size=4]right[/size] at all, you'll have noticed that I said all other things being equal, as you say the laws of physics aren't swayed by opinion. The resonant frequency is inversely proportional to the square root of Mms [size=2][/size] which I'm sure you know. For the non technical the resonant frequency is determined by the mass and the compliance of the speaker. Compliance is the floppiness of the cone support, The bendiness of the corrugated spider and the cone surround combined. For the examples Bill gave the compliance and the mass are both different. That's exactly why I wanted to make the point about it being a little more complex than 'the only difference is dispersion'. You can tune a small speaker lower by making a heavier (and usually stiffer as a result) cone or by raising the floppiness, these in turn affect other speaker parameters. I could give plenty of examples of speakers where the large cones are heavier but I don't think people will have too many difficulties in seeing that an 18" cone will usually be heavier than a 6" cone for example.

Sorry to spoil the party but dispersion isn't the only factor affected by cone diameter. First of all you can't vary cone size without changing either its mass or cone thickness both of which will alter the sound it produces. A heavier cone will resonate at a lower frequency and ultimately reproduce lower frequencies as a result, all other things being equal. It will also take more energy to accelerate and decelerate, changing its ability to track high frequencies and its transient behaviour. It's also true that speakers with high surface areas tend to be more efficient, all other things being equal. Even the dispersion issue isn't quite as clearcut as presented. This assumes the cone moves as a piston, and it won't. In practice they all flex to a greater or lesser degree so that more high frequency sound is radiated from the centre of the cone and for most speakers the effective radiating area reduces with frequency. As a result it is possible for a single 15" speaker both to produce appreciable output at the upper frequencies of a bass and to have acceptable radiation of those frequencies. As in the Barefaced compact. You'll have noticed the repeat of 'all other things being equal' and of course they won't be. There are lots of variables other than cone diameter and all have an effect on the sound the final design will make. What Bill is saying is that there isn't a characteristic 'sound' made by a 15 or a 10 which is completely right, but it is easier to make a 15 go louder and deeper than a 10 and much harder to get a decent top end out of a large speaker. The 'sound' depends upon a lot of factors not just cone size.

The aluminium basket does two things potentially. It is more rigid than its steel counterpart and this might help in the longevity of the speaker. Ceramic magnets can be pretty heavy and the basket can potentially distort over time. The second advantage is that aluminium is a great conductor of heat and the frame may help in cooling the magnet and coil. This could mean less power compression as the speaker heats up. Notice the conditionals, maybes and mights. I've not seen any figures on this though Bill may have some sources to offer. Generally I prefer to go for the cast frame although I've had few problems recently with pressed steel frames. Cast frames are always more expensive to implement and there are potential benefits so they are one indicator of a little more care in the speakers design/implementation. I'm using the Fane 10-300's with the steel frame in my stage monitors however with no problems at all so far.

All of the above is good advice. There are three abilities that will get you constant work and none of them are to do with musical ability. The most important is the ability to network, go to the places musicians hang out and talk to people, listen to them carefully and store up their knowledge and share your own. If they know there's a bassist going spare and one of their mates needs a bassist... Equally if you can help them a bit with a contact they'll remember you and pass you on more often. The second ability is the one in shortest supply with musicians, organisation. I'm a crap bassist but a born organiser, Book rehearsal spaces, gigs, run the PA and lights, blow noses carry spare fuses and wipe their little bums at times. I play with people much better than me and so far no problems finding a band. The third ability is self awareness, what are you actually like to work with and what are you looking for in a band? Know your own strengths and weaknesses especially personality traits and work with them. Also recognise what you are prepared to compromise over and what is a sticking point for you. the more you are prepared to compromise the more desirable you will be as a bandmate. Originals bands are always going to be tricky as it demands big egos. If one of you wants to write power ballads and the others metal it really isn't going to work. If you are open minded and respectful of other peoples tastes it can work better. OK musical ability does matter, but there are so many talented and skilled people out there that it takes other skills to get out of the bedroom.

[quote name='davehux' timestamp='1408018061' post='2526276'] I use a Behringer F1220A http://www.amazon.co.uk/gp/product/B0028GWJCG/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1 Solid, well made, with rubber bumpers on all the corners . Loads of power (forget the 125W thing, it is seriously loud) Nice 3 way EQ. The Feedback filter actually works!!! I know Behringer doesn't get much love on here, but mine gigs regularly and I've had no trouble at all from it. Hard to beat in a 'bangs for your buck' contest [/quote] It seems to me they are getting better. The limits to the 1220's are their volume. Max 113 dB from memory. However for most bands who play on cramped stages this should be enough. Once your monitors start to give feedback problems any extra volume isn't usable anyway. I've not tried them but I wouldn't dismiss them without hearing them.

[quote name='LukeFRC' timestamp='1408054028' post='2526775'] odd off topic question..... say I went and bought a RCF HD12a.... what would stop that (and a preamp) working as a powered bass cab? [/quote] Only the expense. There are several threads on using pa speakers as bass speakers and if you like the sound of DId bass then these speakers should hadle this as well as any. It is still a 1x12 though, so enough for some people but not everyone. Try before you buy though.

[quote name='LukeFRC' timestamp='1408054028' post='2526775'] odd off topic question..... say I went and bought a RCF HD12a.... what would stop that (and a preamp) working as a powered bass cab? [/quote] Only the expense. There are several threads on using pa speakers as bass speakers and if you like the sound of DId bass then these speakers should hadle this as well as any. It is still a 1x12 though, so enough for some people but not everyone. Try before you buy though.

For testing I use a PA amp to get a flat response. Usually a Peavey IPR1600. I've been gigging the cabs with my Hartke 3500. My drummer complained that he couldn't hear his snare when I turned it up so I don't think sound levels are a problem.

Bill is of course absolutely right about this. The interesting thing is about what the implications are for us as bassists. If you want a single speaker to do the job for you then you have to have something engineered for high volume displacement. This usually has a cost in terms of efficiency or a large exotic and expensive magnet system. The other thing is that doubling the number of drivers gives you 3dB of extra sensitivity. 6dB if your amp can maintain the voltage swing. Go to an 8x10 and you have a potential 12dB of sensitivity or 9dB at the same wattage. Although this comes at the cost of the speakers radiation interfering with each other to make a lumpy bumpy frequency response and radiation pattern. This extra efficiency means that your system is using much less power. 3db is half the power and 10db a tenth. So instead of 400W into an exotic lightweight you might be using 40W into an 8x10 for the same sound level, and only 5W into each of the eight speakers. If you are using the same amp it is going to run cooler and maintain its output, it is also much less likely to distort because of peaks in your playing. More importantly probably the speakers will run cool, 400W into a tiny coil trapped in a tiny air space inside a magnet does get very hot. Speakers running consistently high powers run very hot and the resistance of the coil rises reducing the speakers output so the sound changes as they warm up. Of course this is only one variable, there are many other differences to take into consideration but there are distinct advantages in multiple speakers vertically stacked.

I've tried the Eminence delta because I had one laying around, I wouldn't recommend it. We are going to try the Eminence beta 12A-2 which is a much better driver than the old 12A and I hope to get hold of a 3012HO to try. I've cut a load of spare baffles and the speakers are just clamped in so we can swap them really easily so if anyone wants to volunteer a speaker to try..... having said that the Beyma models well and sounds just how it models so is likely to be what we recommend. Stevie has three modelling programs, WinISD, one which uses the same engine that Eminence use and another that I'm not familiar with. I'll let him reply. Interestingly they don't agree with each other all the time.

All good questions. The port issue is really the outstanding detail we need to sort before publishing the design. Exactly the discussions you are having here are going on between us with one extra problem. I'll re read the discussions we have been having and may come back on this but in essence the debate is 'how big a port is big enough?'. More than one formula and more than one target maximum port velocity have been suggested to avoid power compression and port noises. Stevie in particular is keen on flared ports and they do have advantages but I am reluctant to add to the cost and problems of sourcing all the bits and pieces. The other issues are practical ones. If you make the ports too big they are also too long to fit the cab. Since ease of build is high on the design spec I really don't want to have to fold the port and prefer to use a shelf port. The prototype has round ports because this enables me to vary port area and tuning easily. As you suggest the front and rear panels are removable for prototyping purposes. Since this is a home build project and an open source design it is a simple matter for people to adapt the construction to their own taste and pockets. We will give enough information for people to go for the ports they prefer and the construction techniques they prefer. My experience is that using screws and glue is more likely to have a positive result where people are working without extensive woodworking tools so i am going to recommend they use screws. I use Titebond aliphatic woodworking adhesives because that's what my local woodworking shop Axminster Power Tools sells, but I also use ordinary white woodworking PVA. I've never had a joint leak or break.

The art710 is cheaper than the Yamaha from Thomann. I'd choose that.

They were the DXR10 and the ART410 recently discontinued but available here at a discount. BOth makes have excellent reputations for reliability. The drivers in the RCF's have a great reputation. I use passive club series Yamahas and have a soft spot for them but there was a real lack of detail from the DXRs, I was underwhelmed, they weren't awful, just a bit boxy and compressed with a lack of detail in the vocals. Particularly noticeable on a duet with two female voices I use for testing, the ARTs separated the voices, the DXRs turned them into a mush. By the way my Yamaha floor monitors are 15s (bought second hand) another reason to go for 10's is they are too big for most of the venues we play and I have just moved to 10's for that reason. I've also bought some Behringer B205Ds which work surprisingly well for vocal monitors if you want to go really small