$2500, 5 years, 11 projects (not all fullrange)

[just a guy]

I don't pay much attention to times and dates, but my internal clock is telling me I've been persuing this audio hobby semi-seriously for about 5 years now. I've always been interested in and spent money on music and gear, but 5 years ago I knew absolutely less than nothing (and never planned on making anything other than cheap subs for cheap and/or free drivers) but since then I've made a conscious effort to learn more and spend wisely (but not necessarily less).

On this 5 year anniversary, I took some time to take stock of what I had spent (and I mean EVERY penny), how much I saved over retail price on these parts and materials due to my frugaliciousness, and what I have actually accomplished, physically and mentally. I've had much more time than money to spend over this period, so I learned a lot. Thumbs up. I've spent just shy of $2000. Considering that I spent about 65% of retail prices that doesn't seem too bad. Thumbs up. And physically... I've started 11 projects (not including a few of the early subwoofer experiments that didn't cost anything) and had several working models, but I have never actually finished one single project. Two big thumbs down. (Some of these projects listed below are only 'projects' because I have drivers that need boxes.)

This probably should not have come as a surprise (especially to me) but it did, and on the spot I decided that these projects are priority number one, except the latest project (#11 - the rotary woofer) which has been abandoned (to the point that I don't even include associated costs of this project in my comprehensive list of costs - I'd rather just not think about it) and if the rotary woofer is ever completed it will be a novelty, not a serious working subwoofer. Since most of the projects are full range designs I think I'll just blog it all out right here, and won't take too much time describing the non - full range projects. (Although they are tube amp and sub projects, so arguably they belong too.) This process is not going to be fast. And the remaining parts and materials to finish all these will be an additional $550, for a grand total of $2500 spent over 5 years on:

- 4 sets of quality handmade single driver loudspeakers
- 1 quality handmade set of open baffle loudspeakers
- 3 quality handmade subwoofers
- 1 new tube amp with fancy pants binding posts
- 3 delayed/abandoned sub/woofer projects

I will probably only update here as projects are completed. It may take days or even weeks before I start completing these, although I have some really nice motivations coming in the mail, so time will tell. Hopefully this journal will provide some motivation as well.

Some of the completed projects will be gifts for (very) special (once in a lifetime) events for (extremely) important (family type) people (that are likely to use and appreciate them).

[despotic931]

Lol, sounds like me, my gf says I'm distracted too easily to ever finish a project. So, what project will be completed first?

I'd like to finish a project sometime, but you know how it goes...hey look, a guitar...


Hehe,
-Justin

[just a guy]

THE PROJECTS - presented somewhat in order of importance

- all costs for each project listed here are only estimates (in CDN $, and ALL costs are factored in, including building materials, parts, accessories, and any applicable fees (exchange rates, paypal fees, shipping, taxes, etc), since none of the projects are complete yet
- quoted costs may turn out to be a bit low due to my wishful thinking

1. Frugal horn
- I have drivers (108e sigma), but need to build the box
- my total cost $150

2. BIB
- boxes are built (nice baltic birch) and tested with unsuitable drivers but needs finish and appropriate drivers
- my total cost $250

3. Saburo
- I have the drivers (126e) but need to build the box
- my total cost $250

4. Sachiko (may be replaced with BIB depending on how I like Saburo)
- I have the drivers (206e) but need to build the box
- my total cost $350

5. Open Baffle
- I have the drivers (2 Hawthorne Silver Iris, 4 additional 15 inch woofers) but need to build the baffle
- my total cost $525, or $625 if I buy a plate amp which is not a priority

6. Ported/Sealed Sub
- I have the driver (Mach5 MAW15 - originally bought for a low tuned version of the tl sub project) and the box is mostly built (nice baltic birch - this box was originally an OB U baffle) but needs finishing
- the box is 3 cubic feet and will employ a slot port including a port cover accessory so end user can decide on ported or sealed (but it won't be super easy to switch back and forth)
- my cost $150, or $300 if I buy a plate amp

7. Transmission Line Sub
- I have the driver (Dayton Quatro) and the box is mostly built but needs lots of finishing
- 11.5 cubic feet IIRC, 15 hz tuning (very wide bandwidth, but probably won't be used above 30 hz)
- this box has gone through numerous changes and drivers but after going through all the info, I believe that the 15 hz tl with quatro version is the best use of what I have invested here although I may change my mind again before it's finished
- (possible configurations investigated so far include a 12 hz tl version, a 12 hz (very narrow bandwidth) tapped horn version, a 15 hz tl version, a 15 hz (very narrow bandwidth) tapped horn version, a 23 hz tl version and finally a 23 hz (very narrow bandwidth) tapped horn version - and each variation modelled with a variety of drivers)
- my cost $300, $450 if I buy a plate amp

8. Car Subwoofer
- I have drivers and boxes but none that match each other
- this is high priority but probably will not be mentioned again here, unless I make something really nice

9. Tube Amp
- no I'm not building an amp, I'm just changing the cheesy binding posts
- my cost $510 ($500 for the amp, $10 for the classy new binding posts)

10. Jensen Imperial with front firing horn mod
- I have the box (made of 2 inch thick panels - originally they were solid particle board w/ veneer doors) but it needs to be gutted and modded into a front firing horn and extensively braced internally
- this project is not high priority since I would need to buy drivers, but sims show remarkable output with the front firing mods and modest drivers, and extraordinary output with great drivers
- my total cost $0 so far

11. Rotary Subwoofer
- abandoned, may be resurrected, but only as a novelty
- total paid on this failure $160

12. OB Woofers (this project predates the 5 year anniversary by a fair bit, and is only added here for sake of interest because I still use these occasionally and I might just finish them one day
- I have the drivers (4x eight inch drivers per box) and the U baffle boxes are made (mdf) but require finish
- this project may never be completed; the drivers are at least 10 years old and have foam surrounds, and it probably cannot be made cosmetically 'good enough' - I'd like to flush mount the drivers and it just isn't going to be possible at this point without undue effort
- my total cost $!!! - I don't want to talk about it, I was young and stupid

[just a guy]

So, what project will be completed first?

Projects 1, 2, 3, (maybe 4), 5, 6, 7, 8 and 9 will all be worked on at the same time. ASAP, I hope.

10 will be completed whenever I can afford woofers, assuming I actually have a use for it (certainly not any kind of priority status on this). 11 and 12 will probably never get done.

[just a guy]

Still mired in the planning phase I've just discovered that the time limit on the speakers intended as gifts is Christmas. So I've got a lot to do in a limited timeframe.

Due to this fact, I've made a couple of design changes to possibly save time and definitely save money. The one major change I would like to discuss is the project #2, the BIB (and I actually forgot to mention that it is not actually a BIB as built, it is a BIB inspired pipe/horn). The original point of this build was to determine if a 4 inch driver in a large pipe/horn could be used without a sub. The fostex 4 inchers can't. The FR125 with several times more displacement might, but it's a costly gamble and at this point I don't think it's wise to push a 4 inch driver that hard (without a sub) if you don't have to.

After weighing my options, (larger diameter fullrange OR woofer drivers) I think these baltic birch beauties (not so beautiful yet but just wait) would shine as a pair of mini subs.

I didn't want to bring (a lot) of subwoofer chatter into the fullrange forum, but since this is a conversion of a single driver project INTO a sub I think it is still within the borders of acceptable discussion

Anyway, all I want is an opinion. I've looked into a number of 6.5 inch woofers. The CSS and Exodus (diycable) woofers clearly won't play well with my boxes. OTOH, the mach5 6.5 inch woofer will slide right in (although the driver would like just a bit more room), according the the BIB calculator. It's a close fit. And the woofer has about 35x more displacement than the 126 that's currently fitted (according to the specs).

The pipe horns - length - 96 inches
- design - inverted BIB with driver at 41% line length
- mouth size 81 sq inches

The driver
Fs = 62.2 Hz
Re = 3.4 Ohms
Qes = 0.68
Qms = 5.69
Qts = 0.61
Mms = 19.1 g
Rms = 1.31 kg/s
Cms = 0.342 mm/N
VAS = 6.6 litres
Sd = 116.9 cm2
Xmax = 5.5 mm

It won't have the raw spl potential of a tapped horn, but it certainly won't be more than a couple db off, and this design provides way more ~ flat bandwidth than most tapped horns, about 40 - 160 hz I think.

Comments, concerns, opinions all appreciated. If someone could do a model with software that can model the driver position, that would be incredibly appreciated. Also, if anyone wants to suggest any other 5.25 or 6.5 inch drivers which might fit the bill and hopefully cost to much, that would be appreciated too.

[Graham Maynard]

Interesting drivers for sale here -

http://cgi.ebay.com/ws/eBayISAPI.dll...m=300254159403

posted by Doug on the AudioCircle Open Baffle Speakers forum.


Cheers ....... Graham.

[just a guy]

Very interesting, but just by looks I don't think they will fit. I'm looking for something pretty specific. The vas and/or qts will have to be quite low and the fs needs to be ~ 60 or 70 hz and it needs to have as much xmax as reasonably possible.

(All these parameters can be juggled a bit, so these are not strict guidelines, but give a good idea of what I'm looking for.)

Thanks though, all input is appreciated.

[basb]

Stumbling upon this thread, and having a few unfinished projects myself, I'm curious to know if these projects have been finished!

[borispm]

I'm more or less in the same situation.
I've been involved in DIY for three years now.
Just finished tweaking my bipole Aurasound NS3 project after starting it two and a half years ago. Had gone through 4ohm (parallel), 16 ohm (series), ported, sealed, high pass with electrolytic caps and most recently having the rear driver low passed with caps in parallel (which turned out to be the best sounding).
And I have a pair of Markaudio CHR70 laying around, and I'm going to order more and more drivers. Duh...

[norman bates]

Many of us have either drivers and no boxes, boxes and no drivers, amplifiers that work on 1 channel, or other stuff.

Ideally you have a friend that you can resell the stuff you've played with (get half you paid if new and be happy). That way you have more cash to try other things. If I have something sitting (already played with) and I don't rehook it up once every 2 months, I'll sell it real cheap.

I'm trying a new rule (in my head).
I'm not allowed to buy new drivers (subs even) unless I have my current projects done.

and $2,500 ain't bad at all.
You have to do something with your allowance, right ?

Norman