A nice young man called Adam, in an orange apron, cuts some MDF sheets...
A day later, some embryonic cabinet work begins to appear in a make shift workshop...
Meanwhile, a long suffering wife pretends not to notice an 18 inch Goodmans bass driver on a dining table...
Comments
I actually managed to source a 2nd 18P driver last week, which is what has kick started things on this new speaker build (the first, the one in the photo was in an old bass cab I picked up for a tenner a couple of years ago).
I'm imagining a bass/salad bowl instruction manual with different recommended frequencies for mixing various salads depending on ingredients (rocket salad = 47Hz, tomato salad = 52Hz, avacado salad = 44Hz, etc.,....).
Another shorty family too! I'm the, erm, tallest
You taking time out from your Edinburgh Fringe shows Dave
:P
Great project Ben, well done!
Nice one Ben.
Yes, I do enjoy creative projects like this. Especially when they're successful!
Making speakers from scratch(ish) seem "doable" to me, in a way that other hifi components don't (yet). Especially since I worked on the Magisters, and realised how simple a design they are.
I find myself drawn to extremes so the idea of creating something on the Magister model, but turned up to 11, is inevitably where I found myself!
And of course, Google is one's friend when researching / checking details and points of uncertainty.
Also I want to say that I draw significant confidence and enthusiasm from being part of a community like chews, where DIY and tinkering is seen as very possible and desireable.
Quick question, why two washing machines in the listening room?
Haven't switched the Maggies back in to get a comparison yet, but I will.
I tested them with your lovely beastie Col. Maybe I should have used something less precious... :-/
Anyway, all good and the amp and speakers are getting on splendidly. Daren't leave them alone actually. :x
Spikes fitted. A few internal tweaks...
...Utterly awesome bass in combo with the One4 SECA. :-D
:-\"
How about;
Sorry Harry, prefer this version!
Have continued to tweak these. Most recently following playing around with the in-room bass traps.
Basically resulted in L-pads fitted on tweeters (-3.7dB) and mid (-2.1dB).
Pleased with progress to bass weight and cleanliness.
Also interesting to experience / learn how different facets of the speaker design and sound effect others and the overall sound. Beautiful mix of science (at my level!) and art in design “decisions”. :-)
Really need some feedback from fresh ears!
Hopefully Dave’s will arrive soon.
Using L-pads the tweeters are now trimmed down -7.1dB and the midrange back up to -1.5dB.
What's weird is that when these speakers were in their first incarnation (without any L-pad tweaking) I didn't think "blimey these are ludicrously bright..."
The process of tweaking the levels of the drivers has made me realise how it takes a while for my ears to adjust to new kit'; how I tend to hear novelty and difference above all else when I try something new. It seems to take a while for my ears to get over that "oo, this is different" and move on to more fully appreciating what's going on.
Correspondingly, I've often wondered about kit "burning in"...My experience with these is leading me to the conclusion that although "burn in" may(?) exist, that the situation is probably complicated by the subjective experience of novelty.
Entirely possible that burn-in played a part here too of course. Although neither the tweeters nor the woofers were new, I did purchase the midrange unit, crossovers and cabling new for this project. BUT I can't believe that these components "burning in" can account for a subjective 7.1dB increase in tweeter response. I'll blame my ears and brain for at least most of that.
Also interesting is that the tweeter and the midrange are rated more or less the same in terms of sensitivity (tweeter 91dB and midrange 92dB in fact). Assuming these figures are exactly correct (I know, I know...) that means that the tweeter is now at 83.9dB and the midrange at 90.5dB. But to my ears the speakers don't sound rolled-off. So possibly it's my shonky ears, possibly my room. Possibly voodoo.
FWIW, I'm convinced gear does burn in.
The speaker voodoo is interesting, too.
But I do think the subjective experience of “getting to know” new gear might complicate things.
Let's see how we get on...
Sounding good.
Though the midrange dropped back a bit so i’ve taken out the L-pads on those.
And had a bit of spare wood in the shed.
I decided to add a simple brace across the side panels of the speakers.
When lashing the cabinets together 18 months ago I'd added only a front-rear panel brace (to support the front baffle with the big 18 inch woofer).
Since completion, a knuckle rap on the side panels of the speakers had always produced more sound than seemed satisfactory, so I'd had it in my mind for a while to try to add some rigidity in the hope of dampening resonance.
No great research or thought went into this Thursday's bracing. A carefully measured single strip of wood was simply jammed inside the cabinet with some PVA.
The little reading I'd done suggested that cabinet bracing (and obviously braces can (/should) be more complicated than some old scrap from the back of the woodshed) has 2 effects. Firstly a reduction in the magnitude of resonance / colouration and secondly the raising of the frequency of what resonance remains. This is exactly what I've found.
The sound is clearer and smoother. Also the overall sound became more mid-range prominent. And not in a good way. To what extent this frequency shift was due to the relative reduction in bass resonance, and to what extent it was to do with any remaining resonance being pushed above the 800Hz bass-mid crossover point, I don't know.
In any event, the upshot was I spent yesterday listening and tweaking, and trimming back the mid drivers by 3.2dB and the tweeters by about 1.9dB. So, not insignificant amounts. Things have returned to a proper balance across the frequency range. The improvements to clarity and smoothness remain. :-)
(and, the old knuckle rap is generating less sound than it was!)
Of course, I'm left wondering how much more bracing it would be useful to fit. The little reading I did suggested that more is better, but that there are diminishing returns. Given that further bracing may require subsequent tweaking of driver levels (time consuming and possible expense for resistors for L-pads) I'm reluctant to bother at the moment, but may look into it in future.
If I tried to make braces, I'd end up with sawdust!
Interesting, though.