Phil Starr

Hi David, to keep the same tuning you only have to match the area of the round port and keep the same length. Those are the only two numbers that matter. I keep using the drainpipe because it's simpler for most people. if you can calculate pi r^2 that will be ok, but if you are forming a port then it would be better to make it slightly bigger to reduce potential wind noise in the port. I've had a look and something 8x5cm inside measurements and 11.4cm long would work. You can change the shape so long as you keep to 40cm^2 area

Stop worrying about the diameter of the speaker, it's only one of many things that affect the sound. Smaller speakers are less directional so easier to hear if you are playing close to the cab. Bigger speakers are more efficient all else being equal, Any speaker can be made to go low at the cost of reduced efficiency and most of the sound of an instrument speaker is about the midrange not the bass. In terms of cone area a 2x8 is bigger than a 1x10 and nearly as big as a 12 so I'd expect a 2x8 to give a similar maximum output to a 1x12 all ese being equal again. In fact Markbass have the 2x8 as 99db/W and the 1x12 as 100db/W so youd barely notice the difference in sound level. The NY121 is smaller but heavier and the 2x8 an easier shape to carry. The 2x8 has a less powerful amp. The only way to resolve this is to try them both.

Unfortunately this is the answer and only you can really decide yourself. I've been regularly using a single 8" cab with a 130W amp at rehearsal and it's been fine, a 2x8 should be better. I've gigged small venues with a 1x10 too, so it can be done. To an extent it depends upon the drummer, some are more controlled than others and the difference in volume can easily be 10db playing the same songs. It also depends upon your 'sound'. I tend to roll off the bass below 80Hz and use HPF at 50Hz to keepthe bass clean. I try to leave space for the kick drum in the lower frequencies. This alll makes it easy for the speakers. I love the space ship @Dan Dare Dan Dare should always have a ship

If anything was plugged in and powered up it is providing a signal, that might be just a bit of hiss (noise) but if that device is faulty then it could provide the fault for the desk to amplify into the speakers. You'd have to switch everything off or better still disconnect it to be sure it was the CQ causing the problem. The Zoom appears to be lit up which is one reason why I suspected it, I also know from my duo partners rather random approach to fx that the Zoom can be driven into instability if you come up with fx chains and settings Zoom never dreamed of. I used to do a lot of repair work when younger and earning my living as a part time sound engineer/speaker builder. Hence my hatred of intermittent faults, they never happen when the tech has the device. I do suspect B-stock as a result. Someone returns something to the shop and it lays around until one of the shop assistants decides to have a look. They run it for 24 hours (ideally) and nothing goes wrong and it becomes B-stock. You run it for a year and the fault doesn't happen, and then it does. It could be the desk but until you try it without anything connected you can't be certain. By all means talk to a tech, if they repair a lot of CQ's there may be a known fault but I'd be running it just conected to the speakers for a couple of days before I took it in. The spare desk is a great idea, I have a spare M18 in case mine starts playing up and I've transferred my settings to it so it is ready if I ever need it. I'll get my money back if I ever upgrade When it comes to repairs I'm strictly analogue though

That's a very strange noise. I don't think it is a cable. It's not clear from the pic what inputs you have to the mixer. The Zoom seems to be on, was that connected to anything? I've had strange noises (nothing like that though) from my Zoom when the batteries are flat. It sounds to me like something entirely separate from your sound system something mechanical like a relay chattering, maybe on a freezer/washing machine or anything really. It could even be in a neighbours house. That interfeence can either feed into your system from the mains or by radio waves. Anyway the first thing to do would be to disconnect everything from the mixer when you aren't using it and see if it ever makes the noise with everything disconnected. If it is fine at least you will be reassured it's your house and won't happen at a gig. Then reintroduce one thing at a time to see if any one connection causes the noise. If it recurs then check if it is that source which is faulty or the lead by swapping for a different lead with the same source. Good luck, these intermittent faults are often really hard to track down

Just thought I'd show our most recent set up to show the lighting. this was a huge hall probably 250+ capacity but it cgace us a chance to set up as we wanted. The overhead house lights were on so our lights more effective once the ordinary lighting was off, but you can see how effective our lights were by the colour changes on the floor. The phone kind of makes them look like white lights but the clours were pretty intense in the room. We had our six pixel bars running together via DMX using the internal program from one of the lights. They are all on 1m high stands. The rear curtains are illuminated by Two 180W led floods on a sequence program, again with one slaved by DMX. At the back is A KAM REM1 with four PAR's, no longer available but similar units can be found pretty much anywhere. The venue had it's own lighting but we only had axcess to the extremely grimy mirror ball and some old school incandescent overhead floods with straw filters. You can see the ones with the barn doors at the top of the pics. The flashing is to recorded music. The Pixel Bars are around £60 ea and the stands £20 so you are looking at £480 worth of lights in these alone but they were bought a couple at a time and were useful even when I only had a pair. Most of the money I've wasted has been by buying random lights on impulse I'm now planning the lighting a bit more and I think getting better value for money, Now and Then new lights 1.MOV

Sorry David, I can’t help,all my stuff is Apple.

The actual output is affected by quite a number of things. Speakers are inefficient things half the output is from the rear of the cone and the main job of the cab is to stop that from reaching the sound at the front andcancelling it out. with half the air pushed forward and half back you get no movement overall and very little sound. You can try this at home just put a signal into the speaker before you mount it and all you get is a very quiet tinny sound. The speakers work by increasing pressure in front of the moving cone. That 'squashes' the air which then expands back when the cone reverses direction. Those pressure changes are then turned into sound waves but this in turn is inefficient. Bass instrument speakers are typically 1-4% efficient with large cones more efficient than small ones, all else being equal of course. You can check that too, just pop across to Blue Aran and check the reference efficiencies. Horns increase efficiency by acting as 'acoustic transformers' decreasing the high pressure at the throat to low pressure at the mouth so more energy is turned into sound. Doubling the cone area with two speakers couples them and you get 3db from increased efficiency. Power compression is a seperate phenomenon. Coil temperatures can reach 232deg C (Fahrenheit 451, and I had paper coil formers catch fire in the old days) and you can lose 5-6db with copper coils at these temperatures https://en.wikipedia.org/wiki/Power_compression In practice of course we don't put pure sine waves through amps and music at 225W peak isn't the same as a test signal. Different speakers also address heat dissipation with different levels of success so temp rise is always different between drivers but 3db loss isn't unusual. All of this isn't needed to know that a pair of 8ohm speakers gives a huge boost to your sound compared with a single driver with the same amp and 6db is what you'd roughly expect.

I think Rean are made for Neutric anyway. Legally you need to give the retailer a chnce to repair faulty goods and if Andertons are offering a courtesy cab/PA then I think they are playing fair. Hope you sort the problem, not one I've come across before.

I'm the newbie and there's quite a few things above that on the list of things to be having chats about that will refine the set. Things are really positive and moving forward, I need to be selective and focus. I feel your pain, I was going to ask if these are ongoing issues or whether you've joined a band who have been cheerfully getting it wrong for years but I think I know the answer. This is the years of playing together with mistakes accumulating and nobody listening to the originals. Youve probably got a guitarist (usually the guitarist) who thinks learning a song is just knowing the chords to verse and chorus. I reckon a lot of these 'simplifications' are down to a rehearsal 20 years ago where someone turned up under prepared and blagged their way through it and blagged their way through the song covering up their lack of preparation by convincing the rest of the band that 'this is better'. However you are being the grow up. The audience are probably not noticing and having a good time and I'd settle for some nice people and regular gigs over arguing an ending or guitar solo. Well I would nowadays

Rob you might be the first person to try two of these cabs and just stacking them will change the off axis angle between your head and the cab on the top. What you'll gain will be subjectively quite dramatic and most people see it as a big improvement. The most significant is a 6db increase in sound level, even when you turn it down the speakers will be working over the more linear part of their travel so you might hear a reduction in distortion and power compression depending upon what level you were operating at before. Secondly you'll hear a clearer sound as you are closer to being on-axis and you'll also have some mid bass losses from the top cab but reinforcement from the bottom cab. For me a pair of these would be a really viable gigging set up. My current drummer is properly trained and his dynamics control is excellent I was using the 8 last night at rehearsal and it was fine in terms of volume. A pair would have given me plenty of headroom for a noisier gig environment. I'm dying to see what you make of a stacked pair You can already test how the cab will sound on a pole at home. Just stick it on a shelf or a table and sit down with your head/ears at speaker level. One reason I chose the Fane is that the off axis response is better behaved than many speakers of the same size. Speaker cones aren't rigid pistons but flexible bits of paper so off axis response is complicated. In any case the higher frequencies don't disappear off axis, mainly they just fade a little and eventually lobe, this is more of an issue with larger diameter speakers too. Small speakers have an advantage here with the cost being lower output. If you look at the chart below you can see that the reponse dip is dramatic at 60deg but minimal at 10-20deg. Bass guitar doesn't really have much content above 4kHz so the 8k line isn't really relevant.

you'll find that speakers sound very different up on poles. any hard reflective surface will reinforce the bass frequencies in particular and you'll get an extra 6db for each reflective surface. Spacing something away from a surface creates two paths to the ear and you'll get a time delay between the reflected sound and th direct sound from the speaker. That creates points in the frequency response where you get cancellation. I use the same speakers up on poles as PA and on the ground as floor monitors with one of my bands and DI the same bass signal into both. I don't use backline. I have to cut the bass to the monitors by at least 6db or the bass frequencies just drown out everything else on stage, the same signal is crystal clear out in front of the stage. Whether that bass reinforcement is good depends upon what you want to achieve/like. The 8" cab you've built gained a lot of love sitting on the floor but you can experiment with it on a pole. The best stand of course might be your other 8. maybe a stack of four would sound good I've used my 6" cab for open mics. It doesn't have the bass of the 8" cab so I tend to find a corner or a rear wall position for it so I can use the bass reinforcement. It's good to experiment with where you put your cab and you can learn to use the reinforcement as an extra tool. it's free bass boost if you need boost. A real nuisance if you don't. You can also buy tiny speaker stands NJS are one brand currently on offer at UKDJ for £17

How else would a covers band play Sweet Child Of Mine, Jean Genie, Video Killed The Radio Stars!!?? Seriously I've been through rehearsals without touching the G string and even the odd gig but there's an awful lot of times you need an octave in an arpeggio.

I'm with the majority, why would you have two sockets if they aren't left and right. That lead may just be something left by a previous band, who knows. You all use in-ears so it won't affect your performance but it might be worth looking to see if anyone you know has played there and what their experience was. Or ask the venue. It could be a good system if the people who installed it have eq'd for the venue. Good Luck

This is very much John's project and I haven't yet had a chance to listen to his system. Our thought was that at the price he paid the plate amp with a built in crossover was worth the price of the package. We had discussed just about every possibility including my developing a cab and John the amp from scratch and this was cheaper than the parts for the amp. When it turned up it was surprisingly well put together and sounded OK with the original Wharfedales. I did run models to look at using better quality 10's including Fane, Celestion, Beyma and Faital. Most of these gave no increase in output, mainly because they are only available in 8ohms. I did manage to find TS parameters for the fitted drive units as they were being sold as spares at the time. The 120db maximum output checks out as genuine. This compares with RCF/Yamaha and the like who all routinely quote only peak output which is 6db higher than the maximum continuous output they actually develop. The last conversation we had about this was to try the speakers and if they are short of output for John's needs to try some of the drive units I have as replacements. My feeling is that it's not something I would set out to do as a plan and there isn't a speaker for sale at sub £200 that would give you the extra 6db that a second sub would guarantee.

Payment sent, how many more do you need?

My experience is that it is really variable and depends upon who is in charge in individual yards. To be fair the main issues are now in how the wood is grown, slow grown softwood is becoming rare and the species planted have changed. I noticed a steady downhill slope in the 30+ years I was restoring houses and I've a barn full of reclaimed Victorian timber 'just in case'. When I was doing this more regularly I used to check out the timber whenever I was in a yard and bought up the good pieces when I saw them which saved a lot of time compared with having to drive round looking to see who had the best stocks half way through a job. I'm such an old curmudgeon

Correct, it's part of a tuned system and the dimensions have to be calculated

Finger joints are great if you have the machinery. They more than double the glued area and they help hold the cab together and square, just like the reinforced butt joints used in the 'easy build' method. Many commercial cabs use finger joints which are a lot quicker to fabricate than a reinforced joint. You will be changing the volume by removing the battens from my design so you would be best to calculate the volume of the wood you are missing and reduce the cab size by an equvalent volume. "If you have a hammer everything looks like a nail" For a keen woodworker wood is all, and plywood the devil's invention. He's probably envisaging using something with a lovely grain and making a feature of the beautiful finger joints. He's possibly seeing your cab as a furniture making project. I suspect that if you asked him about the Young's modulus, density and internal damping properties of the wood he won't know. Engineered woods are the best material for speaker cabs, tough, stable, easy to finish and the best combination of physical properties. It's kind of your friend to help and it is possible to build a solid wood cab. Some exotic hi fi goes this route and you could end up with something beautiful. I'm not saying dont do it but there are potential issues to think about and if you want the most practical cab then insist on using ply, MDF or high density Chipboard, probably in that order unless you are completely on board with the beauty of wood. As a woodworker I know the allure of a lovely bit of timber but it needs a bit of thought and planning. If this is going to be used for gigging then ply is best if it is going to sit at home then the right wood is going to look stunning. I really wouldn't use pine. I've struggled to get decent knot free dry timber from any of the builders merchants and only by being prepared to go in and personally select timbers. I've not found ayone at Jewsons, Travis Perkins and the like who know anything about timber and frequently it is poorly stored, left out in the rain before stacking and mauled by builders who don't know redwood frome white wood. I make doors and windows and sourcing genuinely joinery grade timber needs a great timber merchant. Your friend may have those skills of course but I think I'd go hardwood for something like this, but what a waste, I'd be looking at that timber and thinking it would make a great body for bass.

These look really great, thanks for the tip.

My coffee time teaser for today (mainly because I'm not 'allowed' to do Wordle) So the first thing to understand is that balanced line signals have an earth that is at 0V and two other signals +ve and -ve. The two signals go up and down at the same time but when + is going up - is going down. When the signal gets to the amp a transformer or a bit of electronics turns this back to an unbalanced signal. In a jack the tip should be +ve and the sleeve is the earth the ring should be -ve and inside the jack socket there are three sprung contacts that touch the plug when it is connected. Many jack sockets also have switches built in operated whenever a plug is inserted, so this can complicate the wiring. If you use the mono jack (the bottom one) then the - and the earth connectors in the socket are both touching the sleeve and are short circuited. What happens next depends upon the grounding arrangements. Since it is working for you then there are no issues. It doesn't work on my Flow 8 for example unless I only insert the plug halfway.

I possibly didn't think this one through did I? Just because you can do something doesn't mean you should. So could you drive headphones with the line output from a mixer? Well yes, what I didn't say was if I thought it was a good idea and the answer is probably not, most of the time. The outputs are almost always balanced mono so you'd need to wire a connector specifically to take that to your headphones and drive both sides. Secondly not all headphones have the same impedance so the mis-match may be serious enoughthat you'd lose a lot of output. I'd be checking the manual before starting this. If a new lead is going to cost you £10 then you are well on the way to a simple beltpack headphone amp. The Behringer P2 is £23. Ali Express are doing one for £13 that looks very like The Behringer and a passive one for <£10 I'm not really sure why you wouldn't go that route. As you were

There is no mystery about headphones and line outputs. Just looking at the Sennheiser IEM100 because that's waht I have to hand they are a 20ohm load and produce 115db for a 1V rms output or 0dbV. Line level is usually quoted as 0.7746V into 600ohms. In practice the output is often fine up to +10dbu and almost always +4dbu or 1.228V rms. So whilst there may be an impedance mis match (leading to a lack of current) a line output from most mixers will go well above 1V and deliver 115db right in your ears, plenty enough to cause you permanent tinnitus and with a good seal able to hear yourself. The headphone amp just gives you a better impedance match between mixer and phones, with a bit of extra gain with and a volume control. Correction: I was just musing about how levels here. I don't think this is a practical or sensible way to go when headphone amps are so cheap. Please don't do this at a gig and read my next post

Hi @scrumpymike can you send me details for payment please

I suppose I'm saying there is something in between. which is probably not particularly helpful The main thing that you want from a bass cab is that it is rigid and strong and as airtight as you can get it. In this case the cab is going to be portable so it would ideally be lightweight and tough enough to take knocks along the way. Already you have to compromise, lightweight timbers are almost always softer than those with more densely packed fibres so even in an ideal world there are choices to be made and probably no simple 'right' answer. Plywood is a man made material, there are lots of variables in it's manufacture. The species you use for the plies can vary and wood itself is a variable product between trees and even within a single tree there can be variation in the wood. Then you have variations in how the wood is handled and the resins and glues used to bind the plies together. There are British standards for the glues used and the resistance of the cores (based upon European Standards) and grading for the quality of the face veneers A-D commonly B-BB where B is the best face but not perfect and BB is meant for the inner surface often with small patches but still good enough to take a paint finish. The last ply I bought from B&Q was graded B-BB. The thing is there is such variation most of us won't try to specify. Often the better grades are only available in large qualtities so you aren't going to be able to specify. I have some block board in front of me with tropical hardwood (FSC) outer veneers 1.8mm thick. Three 8x4 sheets cost me an arm and a leg and had to be supplied by my timber merchant as part of a much larger order. These were for some furniture btw not for cabs. The reality is that unless you want to spend a fortune and hours searching you are pretty much stuck with the ply supplied by the big sheds. If you buy hardwood ply which is grede 2 or 3 (exterior grades) then you are going to get a reasonable quality product. I've got mine from Wickes over the years as I can go in and sort out the best sheets in the pile. If you look along the cut edges you can see if there are a lot of voids and if the edges are separating or splintering. Honestly I doubt if you would really hear much difference in the completed cab. I know a couple of people here who have made a cab with softwood ply I shudder to think about it, but they built a cab that worked. So my advice is to buy the best ply you can find, be aware of the gradings but don't agonise if the choice is down to take it or leave it, you can still build a great cab. Probably the lower grade is ging to affect the finish more than the sound of the cab.