A partial handle on costs
I am beginning to get an idea of the costs of the speakers,
sans crossover components.
The Bhoopali:
The Bhairav:
The costs are for a
pair of speakers. And the crossover costs are not yet known.
The Labour line item is what I've paid my carpenter for each pair of boxes. (I've actually paid him more, but that's because he made mistakes and had to re-do a thing or two here and there.) One trained carpenter of average intellect, with some ability to use a router, took about five days, working alone, to finish one pair of boxes, including the fixing of the laminate.
It's interesting to see that even for a low cost model, my use of thick 25mm MDF and adequate bracing with 18mm ply, results in the MDF+plywood costs accounting for only a very small part of the total costs. This means that some builders who always want to go with thinner and lighter material in order to be "practical" may not find the loss of quality worth their while. And to estimate costs of all sheets (MDF, ply, laminate), I've taken 50% markup over actual consumption to account for wastage. Your wastage may vary, depending on how many pairs you're building.
In case you're curious, I'm paying Rs.90/sqft for my MDF, Rs.62/sqft for my plywood, and laminate was about Rs.45/sqft. Both MDF and ply are what's called "commercial" grade but of very good quality -- they're not marine grade.
One of the major costs I've incurred is the binding post assemblies. This is because I chose to go with expensive premium Dayton assemblies, with metal plates and binding posts (I like them!
hyeah
. You can easily replace the Rs.4,200 with Rs.400 if you go with plastic MX terminal cups. Totally up to you, and they won't impact performance one whit.
For the crossover components, I am assuming that the crossovers will not be very complex, since these drivers are relatively easy to cross over. Therefore, I am estimating that I'll be able to get away with 3 coils and half a dozen capacitors per enclosure. I'll ask diyaudiocart to make me the coils using their 18AWG enamelled copper wire, which I feel is perfectly adequate for most speakers, not just these ones. For capacitors, I will use (if possible) good but non-boutique MKP/MKT caps. You can estimate their prices, to get a ball park of the total project costs, till we actually have the crossovers designed and know the exact figures. My very, very rough estimate is that the crossovers will land up being about Rs.5000 per pair of speakers.
The enclosures are done bar the black painting of the front baffle. Once they're done, I'll fit the drivers, take measurements, and start on crossover modelling. If you recollect
this post, I'd said I have a 9-step process to design and build speakers. As per that process, I'm halfway through Step 4 now.
* * * * *
When I finish Step 5 (the in-box measurements of impedance and SPL), I'll upload the FRD and ZMA files here, as I've been doing for everything else. At that time, I'll look forward to at least three of you downloading and installing crossover design software on your PCs, adding my FRD and ZMA files, and playing with crossover design. I will want at least three of you to actually simulate my crossover design, change the values of components, see how the simulated system's FR (frequency response) curve changes due to these tweaks, and discuss your doubts in this thread. In money terms, it will cost you nothing. In terms of work, you won't have to do any building or measuring -- you'll just have to play with software on your PC. So it should be very interesting but not intimidating.
The process I've been following here of walking through the entire design and build journey will only be worth it if at least some of you lose your fear of design engineering and design tools and play with real data and understand how easy, and how scientific it is. Ordinary mortals like me can't design good speakers just by ear -- but they do it nevertheless, because they don't know any other way and don't have anyone to guide them. And they always land up with designs which are worse than they could have been. I want at least some of you to experience the sensible, easy, engineering approach.
I can tell you right now which software I'll be using: it's
XSim. It's the easiest software to use for tweaking crossover designs. Once you start using it, you'll wonder why you didn't do it earlier. It's easier to use than Word or Excel. And it's free.
