Phil Starr

It doesn't handle 2.2kW. You just can't dissipate that much heat from the coils in speakers that size. Very few 12's can dissipate more than 300W and even if you allow an extra 1" for the 15" with a bigger voice coil less than 500w is likely to be the limit. So that makes a maximum 1100W AES. Probably the power handling is much lower due to excursion limits. Air may be escaping all three sides but the sound? well that's omnidirectional at port frequencies so if it doesn't matter if it is front or rear ported how is that important. Right he's got a 15" driver which is down facing firing through ports and it's "full range" so he doesn't know about radiation patterns off axis or how ports work and it certainly has no crossover. Ouch! The cab is developed from a "40kg" 2x12 and a "40kg" 1x15 and they've saved some weight by sharing a cab? So this thing weighs in at morbidly obese! I suppose it is possible they don't know very much and believe their own hype but if they have the above wrong then you can't trust anything they say. Nice colour though

You could just drop a 12CMV2 in. The cab won't be tuned optimally but it will work for not a lot of money. It wasn't really tuned for the original speaker anyway probably. Then when you have time you can mod the ports the way @stevie suggested. Plan B would be to block off the slot ports completely and cut holes for a couple of drainpipe ports as in the easy build cab. Did you ever put the ports in your house amp?

Hi there, How much woodwork do you want to do and how much do you want to spend? As it happens this 30litre net cab is the same size as the ones we've been playing with recently. I've tried out the Beyma 12CMV2 in it and it works better than the SM212 the cab was originally designed for. Recently Stevie has designed a 110 plus horn cab which is also based upon the easy build 30l design. Both of those could work in the cab you have with a bit of carpentry. The advantage is that they are both tried and tested designs.

of course, you just need a switch between the input and the crossover

And you've left room on the baffle

John, you got the MInimax then, I thought about buying it (I already have one but was looking for something to put into a combo). It went while I dithered. Well done, it was a great buy and good to see it has a good home. Ummmm that soil pipe looks .. well soiled really the speaker should be well damped! Good build, and good to salvage and use the grille, It's the bit of the build I never get round to doing and it will make the final combo look great. I hope it sounds great and if you wanted you could probably add Stevie's horn and crossover later. It isn't designed for that speaker but that means it won't be optimal not that it wouldn't work. Well done.

Hi Marty, this was all before Thiele and Small who developed the theories behind the current computer modelling. Over simplifying they treated the elements of a speaker as electrical elements of a tuned circuit. Before that we understood Helmholtz resonators and that was how they calculated the frequencies of tuned cabinets. The rest was little more than guesswork guided by experience. There were even designs with two different sized inside the same space, treating the ports as being independent of each other. these were the designs I first saw described as hybrid resonators from memory but I couldn't find a reference going that far back. The conventional double cavity speaker is so well known WinISD will model it for you.

And now the drawings, big thanks to @RichardH who did all the hard work, nb the port is 170mm and 100mm internal diameter. We hadn't settled on this when these drawings were made BC 110 T.pdf

Spooky, I actually typed this up a few hours ago and forgot to 'submit reply'. Anyway it must be true then

There are a lot of manufacturers claims that seem to defy the laws of physics. There's also very little new under the sun when it comes to speaker design. There were a lot of designs in the 60's and 70's which claimed to be hybrid resonators, resonating at more than one frequency. That's the earliest mention I know of the term but I haven't had a chance to look at the Barefaced design in detail so I can't really comment. As to books there's a couple I like: The Loudspeaker Design Cookbook by Vance Dickason is great but can be expensive unless you find an early version secondhand. The other I like but it's a bit technical is High Performance Loudspeakers by Martin Colloms. It'll be fine if you have A Level Physics or Maths. I hope they are both still in print Most of the actual design work is done by software nowadays. Most of us amateurs use WinISD which is a bit of freeware. It helps if you know a bit of theory when you are driving the software but it works pretty well if you follow the recipes.

I use a pair of RCF Art 310's with my duo, everything goes through them direct and they are absolutely fine. I use one of them alone for most rehearsals, I've had no problem with volume even with a drummer. I'd probably use the pair if we ever needed them at a gig but our drummer is stupidly loud at times.

Thanks for all the birthday wishes everyone. I not keen on fuss at home but on the plus side I did get a nice pair of closed back AKG headphones for practice and recordings. I'll miss the gaffa taped Sennheisers I've used for years but these are great

That'd be great, I'll pm you later. Hopefully I'll see you at the bass bash later this year

Thanks, can you pm me to get them across

Thanks to you and @Hellzero we are aware of the problems of compression but remember the recording will be just part of what we do. the advantage of our own recordings is we will know that they've been recorded with no fx or eq. Thanks to @stevie we can measure the frequency response of all our designs. We do road testing with our bands in normal times and we all play through the cabs when they are in development. The missing bit under lockdown is getting the cabs out to other players and then being able to give people who are interested a decent recording to listen to so that they can make their own assessment of the tonal qualities of the cab. Hearing other people play even from a recording adds a lot of extra information.

I think this shows all the signs of an immature market. The chipsets are pretty standard but the boards are either populated with substandard components or fiercely expensive. Meanwhile mid price manufacturers are increasingly producing perfectly acceptable amps at good prices with the chipsets available. Behringer/Bugera/Sampson/Wharfedale/ TC and all the badged OEM stuff from Thomann and the like. Unfortunately nobody seems to be making the mid priced reliable boards you'd expect with serviceable but well priced components. @Chienmortbb and I have been talking about the Wharfedale Wharfedale PSX112 350W Active PA Speaker - Andertons Music Co. it's rated as 250W and 100W for the tweeter (within the sort of parameters of the TDA chips John referred to above). The interesting thing is the the price; £114 for an active speaker! The whole package is cheaper than just a plate amp or even just the bare boards we are talking about. Have no doubts, Wharfedale are huge, not the Yorkshire company of old but a Hong Kong/Chinese owner of a whole load of older brands including Quad and Audiolab. Nonetheless if i could get a 250W plate amp or even a bare board for £114 with a power supply I'd take your arm off, the fact that is has a pre amp and all the connectors makes it an extraordinary bargain. I have a Wharfedale Titan here which seems to be a predecessor of this speaker. I think i might have to dissect it.

thanks to all of you, I'll respond properly tomorrow. today is my birthday and I've a three line whip to enjoy myself and not go on Bass Chat. How does that work?

Hi Steve, I've looked at those, well some of them anyway plus some of the YouTubers especially the ones who teach the bass courses. The big problem is that they are often not clean recordings and usually you have little idea of what eq/effects have been applied. There are also copyright problems. I'm thinking that a lot of Basschatters have home studio equipment and probably already have clean recordings of themselves playing bass.

As many of you know I've been building speakers and sharing the designs on BassChat, many more to come I hope. My problem is that I'm not the worlds best bass player and me giving a cab a work out is about as testing as if I went in the ring with Anthony Joshua. Pre Covid I took the cab to people I knew could play and then I also got a good chance to listen. What I need is a few good recordings (at least CD quality) of bass played fingerstyle, with a pick and slap which I can cut down to 10-30 second clips. They'd need to be recorded straight from the bass with no eq or fx and clean of any other sounds, just bass. Ultimately I'll use anything longer for the speaker development process and the clips to demonstrate the speakers. I suppose that if I put the test track up here we could also put up recordings of everyone's bass rigs with a dedicated BassChat test track So if you are stuck at home bored but with decent recording facilities I'd love to start putting this together. All donations gratefully received

You are asking for a splitter. Many DI boxes will do that for you, even something as simple as this.

I can't hear the sound of the Behringers fans over the sound of those in the Peavey Minimax Mind you I can't hear much of anything once our drummer starts shed building.

@Chienmortbb knows much more than I do, I'm a bit analogue class D and switch mode supplies scare the hell out of me.The problem with a lot of this stuff is price. That EV plate amp is £200 and the ICE Power amps are around that just for the board. There are a limited number of chipsets that are widely used and you can buy Chinese made boards for peanuts, but by and large the ancillary components aren't up to spec and they won't be reliable. the suspicion is also there that if they are using substandard components that there will be little or no quality control. John is currently looking for some of the longer established Chinese companies products. The Behringer NX3000 uses the same amp module as the Bugera Veyron as far as I can tell, though the Veyron uses it in bridge mode for more power. I'm using the predecessor iNuke for speaker development at the moment but I've never had a problem with the Behringer PA amps. Pulling apart Behringer stuff it is quite nicely made, very nice considering the price. I 've been wondering about seeing how easy it would be to just rip out the innards of one and install it into a cab. Or looking for a Behringer with blown speakers but a working plate amp.

It's a good example, and she did that right from the start pretty much, her first performance on Jools Holland was an acoustic version. Jessie J - Price Tag (Live on Jools Holland 2010) - YouTube she was called in at the last minute without a band and the rapper on the recorded version. Lucky for us really as the rap on the recording would have sounded really odd with a bunch of pensioners and a West Country accent. We copied the audience participation bit she used instead of the rap and did very nicely with the song for years.

We've been looking into a powered version with John @Chienmortbb doing all the work on amps, I'm sure he'll be along soon. One option I've been trying is using a Behringer PA amp with the DSP as a crossover. that saves you the cost of the crossover too and you can tailor the response with HPF on the bass driver and dynamic limiting for speaker protection. I've toyed with the idea of building the amp straight into the cab. In any case the zlx amp is split between a class D bass amp and a smaller powered class AB for the tweeter with a crossover built in. It won't work with the passive crossover in the BC design. The Inconvenient Truth about your Electro-Voice ZLX-12P & ZLX15P amplifier - YouTube

If you are an originals band I think you really don't have to worry, you'll be playing to a completely different sort of audience to a covers band. The choice is your own, keep to the spirit of the original or make it your own. The only thing is to take it seriously and play it the best you can with the line up you have. Audiences respond to enthusiasm, confidence and commitment as much as anything. Have fun with them.