Got to make it quick tonight... it's late already and I'm tired.
Not much to report really, getting final cab close to completion. Just the handles to do really. I mentioned in another thread (Timp's
build log -
really? 
), that the bottom front handle (right in the mouth) has a massive void, so it flexes like hell as soon as you try picking up the sub. I really don't think I can trust it, so it's on to the drawing board to figure out a way to fix it. I think the best option may be just to cut it out and PL a bit of BB in. Other options include (but are not limited to) a piece of metal sunk into a routed channel (good, as you shouldn't then see it), or use the half round piece to reinforce (it would mean the half round went across the whole width of the sub though
). Does anyone have any other ideas?
The moral of all this messing about:
USE BB!!
So today as neighbours were out, I was going to get all 4 subs stacked and in V-plate formation. I managed this after finishing off the 4th cab with handle cut out (see above) and corners. This is what the stack, MY stack now looks like
The 2nd pic is for AntonZ, so he can see the logos
The cabs are a
little dusty, which makes them look a bit shit, but they will all be getting a good wash once I am done.
As for powering them, they are running 2 per side off iNuke 3000DSP #1. I use a 4 core (to save on loads of wires) from my patch panel in my amp rack into a stage box from Audiospares. They are cheapest Neutrik place I have found in the UK, AND their postage is reasonable for small bits, they don't charge like £8 per order if you are only ordering a few NL4's. <-- Hope that helps someone
Anyway, the stagebox has 2 outs, which I then use to wire in my subs. A little like this:
It means I can soon shorten all my Speaker cables to almost the exact length and save a little on cable, as well as gaining a little power due to reduced cable losses AND gain a bit of damping factor for my speakers. I run 2.5mm² core cable anyway, so the difference is minimal, but it'll be almost a WHOLE PERCENT on the power
using the ol' R=l/kA formula where:
R is resistance in Ω
l is cable length in m
k is specific conductivity (kappa) = 56 for copper
A is the cross section of line mm²
I think the damping factor will improve by a similar amount as DF is just output impedance (of amp) over input impedance (of speaker+wire). Typing that out has just made me realize that around resonance, where the speaker's impedance spikes to a HIGH value, the damping factor (and therefore cone control) drops by a large amount, so the amp finds it hard to control the cone during resonance, which makes sense. I'm starting to get it!!
5 mins later...
Right, that's it, I have a dodgy internet connection and have had to use my phone's connection to finish this post - thought I lost everything, but luckily the back button saved all my typing
Oh, I'm waffling so much that I forgot to say that after setting up the speakers stacked and V-plated, the neighbours came back just as I was about to switch on and give it some welly, so my tests had to be at low(er) volume. Even so, OMG, it was pumping and my mixer wasn't even registering an RMS or a PEAK signal (it's meters go down to -24dB and show
both... yeah, Behringer are shit!). The speakers are positioned in the middle of the garage and are causing cancellations (yes, I can hear them... getting my ears trained
). When I was standing my the CDJs and amp rack, there was a horrible booming, but when I moved around, the sound smoothed out nicely (although there were probably still cancellations, just not at any important frequencies for the particular track I was playing).
Also have been checking in Audacity my favourite test tunes, as I thought they went low... not one of them got below about 45Hz!! Have scanned my tunes dir, and got some that dig a lot lower and I'm looking forward to getting them on the rig tomorrow. It's all coming together. Bwoahahahahaha!
Would pink noise be the best to do this test with for a more 'over all' sound, or would it be best to use a 2.5kHz tone where the issue should be more pronounced?
