Phil Starr

Here we go. It's pretty clear that the higher tuning improves power handling at all but the lowest frequencies. At 80hz the power handling of the 40hz tuning is reduced to 100W, but at 50Hz only the 70Hz tuning is incapable of handling the full 200W thermal rating.

Another coffee break, so looking at the graph above a 1db difference is only just going to be noticeable but there is a 2db peak with the highest tuned cab which is really going to warm up the bass, pschoacoustically we hear this area as bass and this is the sort of response a lot of the old 60's cabs often displayed. Quite a few modern cabs too, if you like MarkBass with the tweeter disconnected this might be for you. the problem might be with EQ. If you have a traditional bass controlthen boosting it to get a few extra db at 50hz might well give you problems at pushing that 120Hz peak even higher. At the other extreme the lowest tuning has a slow roll off which starts quite high and that will probably sound quite good with some gentle bass boost. The middle option looks interesting, just over a db more at 80Hz up to 120Hz and the same output at 50hz. there is a hump but at less than 1dB it isn't going to be significant. Of course this is only frequency response, if you want to use this cab at gigs we need to look at how tuning affects power handling.

Here we go, I'm doing this at coffee breaks which gives an idea of how quick WinISD (and other modelling programs) allow you to work. For this I've done my usual routine of making a basic assumption and running through the options I know are most likely to work. For this I've assumed you want it as small as practicable and to me that says 55litres. This graph looks at tuning and I've tried 40Hz,55Hz and 70Hz (green,purple,red) That doesn't tell you how it will sound, but i'm specifically looking at two things here. How quickly the deep bass rolls off (below 80Hz) but more specifically how the cab shapes the response above 80Hz. I find it most useful to look at the area of the graph rather than any specific point on the graphs but then ask myself a few specific questions. As you can see the higher the tuning the more bass you get in the 80-160hz octave, that's counter intuitive but you can see you lose out at 50Hz so you are trading rich harmonics for weaker fundamental. I can see other people are reading this thread so if you feel I'm being over pedantic, well I can't forget I used to be a science teacher

Peavey Scorpion 15.wdr I really liked the cab you showed with contrasting timbers forming the corners. My 15"cabs are only 350mm deep and using something 25mm or so all round each panel in a contrasting timber could look quite good. That would enable you to have a really big radius on the edges too if you wanted. It looks like that is how they made the cab you have shown. I know it means extra work but if you have a biscuit jointer it shouldn't be too hard to form. I don't know where you live but round here you can buy bigger timbers and even get them to make up larger jointed boards at a price. Alternatively I've used veneered panels with timber edges to make up cupboards and they can look quite good. All this looks expensive though, unless you have a supply of well priced timber or have a lot of off-cuts in stock. Are you sure this is the best place to start? If I was going to invest maybe £100 on timber and quite a few hours work on the perfect cab I'd want the perfect speaker and I'm not sure the Scorpion in a 50l cab is that.

Bad luck. Like the others it sounds like it could be a power supply issue if the screen lit up for long enough to reset. Try batteries. One possibility is the input jack, that's what switches the thing on and off. It's probably working by the sleeve on the plug shorting the ring and sleeve connections internally, though there could be a switch. Try a bit of switch cleaner on your jack lead and maybe give it a wipe. I'd avoid spraying inside too much so you might clean the socket with a bit of switch cleaner on the plug and a wiggle in and out. Other than that it could be something simple internally but a repairer is going to want a fixed charge to open it up to look and that won't be much less than a new one. Good Luck

Funnily enough I just decided to revisit this after some good reviews from the Southwest Bass Bash. The 'extension cab' was built to match the original combo internally it measures 304x250x150mm which is 10l plus space for the driver and the port is 50mm internal dia and 55mm long. No guarantees it'll work as well with another driver but it's a fun project. I'm intending writing this up as a proper project over the next few weeks

They've already indicated this is a possibility. I'll get back to them when I 've taken it a bit further and I've got a bit more to show them.

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UNDER DEVELOPMENT Hi All, as most of you will know a few of us here have been developing a series of cab designs on a similar line to creative commons. Free for anyone to use, share or add to so long as it is done on a not for profit basis. So far we have developed a 1x12 Basschat Mk1, a smaller easy build version of the 1x12, a very high quality lightweight FRFR 112T currently described as the Mk3 (the mk 2 was withdrawn when the drive units ceased to be manufactured) and a low cost 110T. I've also built a 1x6 'House Jam Combo' in the build diaries along with a 6" House Jam home practice speaker, a lightweight 2x10 and a 1x15 not yet published but which I'm happy to share. I'm sure there will be more to come so that we will have a fairly comprehensive set of designs. The problem has been that with the passage of time (we started in 2014) the designs have gradually become lost in the thousands of topics posted on BC and a lot of the original illustrations/photo's have been lost when file sharing sites went down or became subscription only. My aim is to make sure you can get all the links to the original designs from one place and to go back and retrieve as much information as I can to aid anyone who wants to build these designs. I'd also like to achieve a little standardisation to keep the design threads as short as possible but with plenty of helpful practical hints. At the moment most of the designs are long rambling threads going on for many pages. I'll link to those threads to start with but replace them with links to the edited designs as I get time to do them. I'm going to reserve a few replies so i can easily edit this thread please don't comment for the next 10-15 mins Basschat 12 Mk1 single 12" driver, 350W, 122db, 14kg easy to build 1x12" Mk1 112 Basschat 'Easybuild Cab' Smaller version of the Mk1 with a tailored bass response to match difficult acoustic spaces (pokey pubs ) this has a video of a live build (in under an hour!) at the Southwest Bass Bash Easy 12" cab build Basschat Mk3 lightweight 12" neo driver with neo horn very high quality FRFR design. FRFR 112T Basschat 110T Easybuild Lockdown project. A lightweight 'easybuild' 1x10 with a good quality horn. The crossover has only three components and requires no soldering. Basschat easy-build 110T House Jam Combo/speaker A remarkably competent and loud 1x6 perfect for home practice and semi acoustic work. This is a build diary with minimal design details but I'll look to write this up as a design as soon as possible A House Jam Speaker

I do wonder if we shouldn't boycott MarkBass stuff until they sort out their customer support. The idea of paying out a fairly substantial sum just to be told your amp is uneconomic to repair is just not a great way to treat customers. I'm another facing a £200+ repair bill for a complete board change for what is probably a simple component failure. I'm fairly competent with electronics but the idea of taking on switch mode gear and surface mounted components is fairly daunting particularly without a circuit diagram to work from. I don't know if the rest of Europe is better served but I'm certain that if MarkBass cared about their customers they could negotiate a better deal than that currently offered by Real Electronics. It is possible that with a fair proportion of bassists signed up to Basschat we might have enough muscle to gain better support from MarkBass in the UK. @MoJoKe is this something you could raise with MarkBass?

Hi I'm also getting a feel for your level of competence and you don't need very much support from me, just someone to bounce ideas off and maybe help with a few decisions. As you see I came up with a 55l 'solution' as a bit of a sweet spot with a -3db point of 70Hz. Doesn't look like Peavey did get it wrong Don't worry about the triangular port, they aren't wrong but we can do better and we'll recalculate for whatever cab you decide to build anyway. I wouldn't say the Scorpion 'benefits' from a smaller cab. If you go back to my first post you can see what changing cab size does to the response on the graph. It is however remarkably tolerant of different cab sizes. Anyway all you have read ties in pretty much with what WinISD is telling me. I'll have a look later at what effect differing panel materials will have on the weight of the cab but it looks like you are accepting a 50-60litre cab as a good compromise. It'll give you plenty of output in the 80-160Hz range and enough below 80Hz not to be disappointing. If you like the showman sound then it's going to fine for your needs. Before you build let the software do the experimenting for you, you don't need to build multiple cabs nowadays. I think most of your decisions are made.

If you are prepared to use another speaker to get a more room friendly size this is a 102 driver in a 30l cab compared with your scorpion in an 80l cab. I've pretty carefully matched the frequency resonse down to 50hz so the bass response is going to sound very similar. The scorpion with it's much larger surface area is going to be noticeably louder though . So over to you. New (or used but smaller) driver or if not how much are you prepared to compromise the bass response to get a cab that works for you?

OK Green and purple you've already seen. Green is your current response with an 80l cab and purple is what your Scorpion would look like in a 30l cab. I wouldn't like to see that much bass missing and It wouldn't give anything like the bass in the video clip. I think Red is a distinct possibility. It's in a 55l cab retuned to give a slight peak at just over 100Hz to warm up the sound and -3db is at 70 Hz so all your second harmonics will be there. I think this will sound great in your living room where deep bass can be just a bit of a nuisance. It was the best compromise I could find that would keep that second harmonic (80Hz -160) rich enough to sound good. The old school sound you like from guitar speakers lacked a lot of deep bass which they compensated for with rolling off the upper frequencies with the tone control on the bass. No guarantees but you might well be able to achieve the sound you want this way. Is 55l small enough for domestic harmony as well?

Hi, I've been chilling out after entertaining friends for a couple of days and thought I'd revisit your design. Without exact measurements for your cab I'm thinking it isn't much smaller than 80l. Fiddling around with different sized cabs I think you have a couple of fairly simple choices. The first is that if you keep the Scorpion then it works well in a cab of 60-80l. Any reduction in size loses a bit of bass. Your choice is: to go for a really small cab like the easy build 30l cab and just accept it isn't going to have good bass output but that's something you can live with. Small size is more important than sound. build a cab similar in size to the Peavey cab but reduced by housing the amp elsewhere. this keeps the sound you have and you could shave a little bit off the size and be OK Go for a middle option of a roughly 50l cab which loses your bass but keeps good reproduction of the upper bass/second harmonics. There is another option you can consider, if what you want is a living room friendly cab then buy a different speaker that suits the 30l cab. I can give you more or less the same response of your current speaker with a 10" driver. It just won't be as loud but it will be in a smaller cab. I'll put up a couple of graphs from winISD to show you how this looks.

Welcome to Basschat This is my practice set up too, I use a Zoom B1ON which has been updated and is now the B1-Four Zoom B1 FOUR Bass Multi-Effects Pedal at Gear4music It has many amp emulations and bass effects, metronome and drum machine, an input for audio devices so you can play along and a decent headphone amp all for £65. A lot of people here use the same set up of Zoom+Headphones. I find the drum machine particularly useful for tightening up my playing and learning tricky pieces. You can play it slowly and speed it up gradually but mainly it sounds great and that makes me want to practice. Some things are just 'right' and this is one of them. I'm not a big fan of practice amps, it's quite hard to make a tiny speaker sound really good for bass and 'proper' bass amps can always be turned down. There are things like the Phil Jones amps but they are really proper gear miniaturised and are really quite pricey. If you want to save space and money and also have a great sound go for the Zoom.

It's true, you were more interested in the bass and I noticed how enthusiastically you were adjusting the bass boost, I was seriously concerned for my little sixer as the level was already quite high. It actually coped fine.

One more, this is a Celestion G12 guitar speaker in the 30l box which I built for my guitarist. this is a more typical old school response, more like what is in your video.

OK this is your Peavey in a 30l cab, again compared with it in a 60l ported cab. As you can see it is creating a small peak and pushing the -3db point upwards. My concern though is that you are 7db down at 80Hz. that 80-160Hz is essential to a bassist IMO as it covers the second harmonic for the whole bottom octave of a 4 string. The old guitar cabs often had a strong hump in that area. having said that the roll off of the 15 in a small box is gradual and you could safely apply quite a bit of bass boost with a speaker this size in a home environment. I've never built a speaker with that sort of response so It's an educated guess as to what it would sound like

I'm loving the finger joints and the way he's formed the corners in a contrasting wood, lovely attention to detail. The 'easy build' is really just the adoption of reinforced butt joints and drainpipe ports. I build a lot of cabs and can't stop experimenting so a quick build with no clamping suits me. With the easy-build carcass you can also just screw the back and baffle in place so they can be removed if you are still in the development stage and need to change things. You do get a bit of panel damping from the battens and the extra weight is minimal.