Wavecor Ardent Journal - the first Builds

[5th element]

It's nice to see that that worked out, the upper area looks considerably smoother now and more in line with the response you posted in post 357. It's also nice to see that the reverse nulls remained largely unaffected too as I did wonder about the change affecting the phase response in a detrimental way. Then again, you can faff about till things pop into place. A little asymmetry never hurt anyone and things there look nice, especially the impedance too. A word to Neil Patel, amplifiers like easier loads and speaker systems sound better for it! A minimum of 4 ohms with the only difficult phase angle appearing in conjunction with an impedance of 15 ohms. Aside from the shallow dip through the midrange, these could almost qualify as an 8 ohm load as they hover above the 6.4ohm minimum for most of their working range. They would certainly work decently well from the 4 ohm tap of most valve amplifiers, unless stupid SPLs are required.

Did you manage to get around to measuring any of the 8 inchers, or was this all catch up time for the Ardent, from not having had your scope on hand before?

[JonMarsh]

You're right, it's been an all Ardent channel weekend, in order to try to catchup from last weekend.

Yeah, where it dips to 4 ohms is pretty benign phase wise. This should be an easy load to drive, other than low sensitivity. I bet my friend's JL1 Signature 100W tube mono blocks would do just fine... :B

No start on the detailed 8" measurements yet, I did get in a set of three baffles for custom routing for each one. I've been looking at the calendar and realize that to have any hope of getting the Ardents ready for the Northern CA DIY May 3 I'm going to have to prioritize and go pedal to the metal on these- I'm even trying to figure out how to schedule in a half hour of work at least two evenings this week after I get back from work at 9 PM. Need to do some epoxy fill touchup on side seams. I've got a work plan through the end of this weekend, and figure I need to plan the work, and work the plan!

I'll also see if I can get away with taking off Friday and Monday around Easter, like I usually do- that will free up some work time, too- may make all the difference in the world!

That includes building a test crossover section for woofer and tweeter, as well finishing the preliminary sanding on cabinet 2 (without drivers) and doing the epoxy coat prior to veneering. Then any remaining time will be for a test modification of an older Isiris midrange into this configuration for testing. that's pending whether I've got the necessary parts kicking around in the parts drawer, or can unwind some inductors.

[JonMarsh]

Still more OCD...

Ordered some more caps for testing... with regards to tweeter voicing.

I usually seek to do a slight bump up in the response in the crossover region of an LR style crossover on axis, to compensate for what is otherwise a slight power response dip through the crossover region, but with the dispersion of these drivers, and considering the frequency region of the mid to HF crossover, maybe that's not the way to go.

So reviewing things a bit at lunchtime in LspCAD, I determined that dropping the value of C4 from 4 uF to 3.3 uF will give us a very smooth on axis response- in this area, this may give the system a more polite presentation, which may be a plus with a lot of electronics.



though not captured and shown here, reverse null is still very good.



Anyway, more caps on order, and measurements and listening tests will be the order of the day before settling these values.

I think this is getting pretty close. I probably shouldn't really be doing this phase in public, makes me look like I can't make up my mind, but frankly, this is how the process goes for me- a fair amount of perspiration to make up for only a modicum of inspiration! :W

[benthe8track]

I think this is getting pretty close. I probably shouldn't really be doing this phase in public, makes me look like I can't make up my mind, but frankly, this is how the process goes for me- a fair amount of perspiration to make up for only a modicum of inspiration! :W

My design process is similar, lots of revisions, stepping back from it as much as time allows. More room for light bulb moments I figure.
We covered transfer functions in school but they never made much sense to me used in the context of controlling liquid tank levels and such. Watching this process however is a lot more engaging and makes me wish I paid more attention to transforms and transfer functions. The more I read the more I see how many parallels there are between flowing electrons and a flowing liquid, which is pretty neat. Keep up the great work!

[5th element]

When I start a design I tend to play around with the design files in an active set up first of all. Mainly because they tend to be more flexible and/or easier to optimise about target curves. Once I've got the gist of that, I'll swap over to a passive solution. Note that this is all in simulation. Going active there is merely another tool to see how things might fit together. I usually already have a target in mind, such as Jon's Dueland approach and sometimes that target plans out, sometimes it doesn't and that's when you have to get inventive! Only once things are working great in the sims do I ever build anything solid. Then comes the fun part of trying to cobble together a passive xover that actually uses up parts in the parts bin, rather than having to order a bunch of speaker parts. I got away with that on the last design too and used up a fair amount of the useful stuff, next time I wont be so lucky I feel! And yes, I feel your pain about not having parts, or having to wait for things to arrive to progress, it can be most frustrating. In fact I filled in a questionaire for RS components the other day and one of their sections was rating things from 0-10 about how annoyed you get by certain things and one of them was - waiting for parts to arrive - I gave that a 10!

[JonMarsh]

It's great when you can use parts that have been on hand, maybe left over from another build and it's modification. But often I just have to bite the bullet and order stuff liberally, like I've been doing the last few weeks. THEN it is REALLY annoying if they don't have garden variety stuff (for me!) in stock, like the standard mid value Jantzen Superior Z parts, for example, or the full range of Mundorf 20W resistors (though Madisound is pretty good about having stuff available these days- other than super expensive Accuton, for example).

So far the logistics on this and the Isiris builds/updates have been going pretty well- got in the Isiris Test Article 4 tweeter update parts ordered on 2-26 yesterday evening, and the order for the new Ardent woofer crossover parts from PE and the tweeter order from Madisound should be in by the 7th. This should put me in good shape for the weekend...

I'll try to get the nice documentation updated in my minimal spare time the next couple of days. Figure it's best to do running updates as I go, so there won't be so much to catch up on at the end!

[JonMarsh]

Rev 4 "Official Build Schematic" which is by no means finalized, but likely fairly close... (i.e., if I get run over by a bus on the way home, use this for your own build...) :W





Some midrange inductors and other parts ordered today. This should start to give a clear idea of the end target price wise, which can be sort of reasonable... a balance of nice parts and fairly good parts where fairly good gets the job done OK.

[dar47]

Okay, I'm going to take a run at costing this one and maybe one with fewer larger ESA caps in the mid (could help with cabinet fit). Madisound have some MRs on sale to so maybe you hit some?. I've got time now I received my veneer and it's going back, not rustic at all and just looks like flat cut cherry pieces sliced together with no variation in color. Definitely not going to match my center. :M

[JonMarsh]

Okay, I'm going to take a run at costing this one and maybe one with fewer larger ESA caps in the mid (could help with cabinet fit). Madisound have some MRs on sale to so maybe you hit some?. I've got time now I received my veneer and it's going back, not rustic at all and just looks like flat cut cherry pieces sliced together with no variation in color. Definitely not going to match my center. :M

That's a drag about the veneer! That is the risk of buying online- I still haven't looked at my Maple PSA backed veneer completely, but since it's from the same company as the solid stuff, I expect/hope it will be similar.

I tried to configure the crossover cap selections for compactness, but you could probably go further with different midrange caps- I'm paralleling a couple of premium caps with a more standard grade. On the tweeter, try to go for the good stuff; however, the MR's are huge, and the Jantzen Superior Z are smaller and also have anti-resonant construction. I did get some of the MR's on sale for the newest Isiris tweak.

Costing out from this should make a reasonable estimate.

*******************************

Oops! Just noticed I left out the 2.2 uF cap in parallel with L4 on the system schematic- will have to update that tomorrow!

[5th element]

I'm sure there are lots of people who are pleased to see a more finalised crossover appearing. As a note on capacitors, not that I've tried them myself (yet), but I've heard that some PP motor start/run caps can be excellent in audio xovers, such as

http://uk.farnell.com/ducati/4-16-10-15-64/cap-film-pp-10uf-450vac-snap-in/dp/1219056

for example. They are definintely built to last, work at very high voltages and often have very low ESR. Considering your line of work Jon, you might have already gone this route before! I just figured that because a motor run cap isn't considered a 'boutique' for audio part, you might get far more bang for your buck, as there isn't any snake oil being put into industrial applications.

[JonMarsh]

I'm sure there are lots of people who are pleased to see a more finalised crossover appearing. As a note on capacitors, not that I've tried them myself (yet), but I've heard that some PP motor start/run caps can be excellent in audio xovers, such as

http://uk.farnell.com/ducati/4-16-10-15-64/cap-film-pp-10uf-450vac-snap-in/dp/1219056

for example. They are definintely built to last, work at very high voltages and often have very low ESR. Considering your line of work Jon, you might have already gone this route before! I just figured that because a motor run cap isn't considered a 'boutique' for audio part, you might get far more bang for your buck, as there isn't any snake oil being put into industrial applications.

I have experimented with this more for the power amp side of things; for instance, the low ESR multi-terminal film caps designed for motor drive bulk bypass work very well for power amp bypass for the same reasons.

OTOH, I do think that in the speaker area, the research Clarity did into cap mechanical resonance is spot on, and construction used in the MR series (polycarbonate tube or the Jantzen Superior Z aluminum tube) is the way to go to control electrostatically induced excitation of resonance, and recommend at least using that for the tweeters. I also prefer using it for a low ESR bypass on the midrange; seems that it will take most of the higher frequency energy, while a cheaper cap (Standard Z or Cross cap) can handle the lower frequency portion. Just low ESR by itself is no guarantee, I think...

[JonMarsh]

OK, updated the schematic, adding in C9 and updating PE parts numbers where suitable for possible component choices.



This is at a level of detail sufficient for preparing the BOM directly, for the most part, so with luck I'll find some time at lunch today or tomorrow to update that. I estimate the cost will be quite a bit more reasonable than the Isiris, as well one would hope.

Now soon I'm going to be doing some head scratching to see how best to package this into the enclosure. Given how the bracing is arranged, if it goes completely internal, I think it will have to be split up into three boards.

OTOH, I'm thinking a little outside the box, so to speak, and pondering the idea of making a new, taller base, tall enough to have a hollow part inside with a single crossover board. One ring, er, board, to rule them all. This could have two or more advantages- easier future updates or mods, a single more compact board with fewer connectors, and not using internal enclosure volume.

Whaddya think, guys? Do we have a show of hands? (you might be able to tell I'm not really used to this collaboration thing, having a personal working project style more aligned with Evil Twin than a corporate team player...) It would make the base design more complex, but could even use the existing base as a template to layer up the rest- in fact, that could be just a hardwood strip around the rim... have to look at this closely on Saturday. But I think its an idea worth pursuing... I'll give it some more thought.

[benthe8track]

OTOH, I'm thinking a little outside the box, so to speak, and pondering the idea of making a new, taller base, tall enough to have a hollow part inside with a single crossover board. One ring, er, board, to rule them all. This could have two or more advantages- easier future updates or mods, a single more compact board with fewer connectors, and not using internal enclosure volume.

Whaddya think, guys? Do we have a show of hands? (you might be able to tell I'm not really used to this collaboration thing, having a personal working project style more aligned with Evil Twin than a corporate team player...) It would make the base design more complex, but could even use the existing base as a template to layer up the rest- in fact, that could be just a hardwood strip around the rim... have to look at this closely on Saturday. But I think its an idea worth pursuing... I'll give it some more thought.

On thing I would do differently would be to mill out the bases to give it a bit more room. I was hesitant to even add the 3rd layer of BB for the base it may look a bit funny if it's any taller but I only know from the model.

I was thinking of making a "3d" cross over that uses standoffs to build it up like a little tower. Otherwise I think you're right you would need to make 3 boards and mount them on the inside walls.

[TEK]

I would have it in the base, but not on the cost of having a base that looks unatrual big.
Not sure how you are planning to solve it, but as the plate itself is smaller than the speaker, I assume you could make the base extend into the speaker without beeing more visible from the outside?

[JonMarsh]

I would have it in the base, but not on the cost of having a base that looks unatrual big.
Not sure how you are planning to solve it, but as the plate itself is smaller than the speaker, I assume you could make the base extend into the speaker without beeing more visible from the outside?

Possible with a fresh design, but not using the existing build without modification.

Note that the base as built by our Canadians is about half the thickness of the original Ardent base... maybe even less.




Another way to make use of whatever height might be determined to be the minimum necessary, would be to use some half inch CE phenolic sheet as the top plate of the crossover base, minimizing the thickness and maximizing the stiffness- I have some purchased for another future project, but more is available from my eBay source.

either put a couple of ribs on the top side for bracing, or double this up to 1". No braces needed. Next question is whether 1-1/2" is enough internal component height, depending on the component sizes and layout.

Something to investigate. bolt holes could be recessed almost all the way to the phenolic, or all the way. I'm liking how this is shaping up in my mind.

Floor is open to more comments, including the wine bottle. :W

It may all be a moot point if the crossover won't fit in that footprint, but with the shrinking component count and size, maybe we have a shot.

And obviously, if this can work, just because I decide to go this way doesn't mean anyone else has to...

[Steve Manning]

Next question is wether 1-1/2" is enough internal component height, depending on the component sizes and layout.

Jon .... I would think that an 1 1/2" would be a little shallow. The crossover compartment in my 1071's is 2 1/2" deep and believe the caps you are using are larger than what I have in mine.

Steve

[JonMarsh]

I agree completely Steve- my thought is that the minimum is 2-1/4", maybe another 3/4" to also accommodate an explicit crossover base, though if I use a phenolic backing plate, that may as well be the base. As near as I can determine now the biggest parts height wise are the 15 uF Superior Z caps and the 68uF Cross Cap, being 51 mm and 48 mm respectively. The big inductors are about 38 mm high, 1-5/8". So, 2-1/4" should get me there...


From this point, it's a floor planning problem. No way would the Isiris crossover fit, but it's worth taking a look with the parts to see if there's a chance this will fit. The 0.4 mH inductors are only about 0.6" tall, 1-3/4" diameter. Might have to shop for parts to minimize area in some cases.

[JonMarsh]

Another thought keeping it simpler and cheaper for the top of the base platform is just 3/4" BB ply or tooling ply for the top piece, perhaps with a couple of backing ribs from scap LBL or maple 1x3's for stiffening. Overall the total needed height would be 3" if using 3/4" BB ply. This is about what the original Ardent base was, as shown above.

[dar47]

This isn't as bad as I feared, this is close (last one) but you keep changing faster then I can add.:W


Wondering if the mid cross-caps could benefit from from ESAs as that is not much of an add on? Your not showing the L4,1.5mH as an Erse iron core but I assume that what you intended? The only other thing is the availability of some of the 20 watt resisters. So probably $1,400 a pair for the Supremo.:B

It will be interesting to see if you can manage to get a least the mid section under or just inside the base. I feel better today as the nice people at Oakwood Veneers sent me some picks of different veneer closer to what I was expecting so it should just cost me some time.:T I don't know why I didn't think to ask for pics as I did think to send them some of my CC.ops:

[JonMarsh]

Wondering if the mid cross-caps could benefit from from ESAs as that is not much of an add on? Your not showing the L4,1.5mH as an Erse iron core but I assume that what you intended? The only other thing is the availability of some of the 20 watt resisters. So probably $1,400 a pair for the Supremo.:B

Yeah, that BOM total isn't looking bad at all! :T I didn't get to that part at lunch time, but there's possibly tomorrow or Friday.

It will be interesting to see if you can manage to get a least the mid section under or just inside the base.

Re Cross Caps versus ESA, it might be an improvement, but in the LF, or when bypassed with the Superior Z, I don't know...

You're right, I planned L4 as the 500W Erse, that's the part you'll see if you pull up the PE part number in search on their site. Similar part (in construction) from another vendor is OK, if that works better for you. It's not my intent to be a schill for Parts Express, but I've generally had good results with the Jantzen parts. And spot tests of them for ESR, dissipation factor, look good, better than the Dayton Audio PP's.

I should have a lot of the parts to look at by this weekend, so can cut out a piece of paper or MDF or phenolic for the available space and try some floor planning- I think that will be faster than making footprints to play with it on the computer!

I hope the Oakwood veneer works out- they have a good rep, and I've gotten some good stuff from them in the past.

[benthe8track]

Jon .... I would think that an 1 1/2" would be a little shallow. The crossover compartment in my 1071's is 2 1/2" deep and believe the caps you are using are larger than what I have in mine.

Steve

[ATTACH=CONFIG]23008[/ATTACH]

That's really clean, well done.

The BB the bases are made of are 2-1/8" but there should be 4" of clearance under the bracing. A combination of 1" pocket(could use a router or better yet throw it on a manual mill) in the bases and stacking in the footprint should work but I don't have the parts infront of me so that's mostly guessing.

[JonMarsh]

The parts from Madisound (tweeter shunt inductor and Mundorf resistors) arrived, and some of the caps from Parts Express-- the rest should be here tomorrow, with any luck, barring unexpected winter storms! I always look forward to more pretty crossover parts...

I think we all have different notions of how the crossover packaging might work; what I'll be investigating is somewhat like Steve's approach, but how it pans out remains to be seen.

[Steve Manning]

I agree completely Steve- my thought is that the minimum is 2-1/4", maybe another 3/4" to also accommodate an explicit crossover base, though if I use a phenolic backing plate, that may as well be the base. As near as I can determine now the biggest parts height wise are the 15 uF Superior Z caps and the 68uF Cross Cap, being 51 mm and 48 mm respectively. The big inductors are about 38 mm high, 1-5/8". So, 2-1/4" should get me there...

Jon - I had the same 15 uF Superior Z caps though I had a 82 uF Cross cap vs. your 68 uF. The board I mounted things on was 1/4" thick and things fit nicely.

Steve

[Steve Manning]

That's really clean, well done.

The BB the bases are made of are 2-1/8" but there should be 4" of clearance under the bracing. A combination of 1" pocket(could use a router or better yet throw it on a manual mill) in the bases and stacking in the footprint should work but I don't have the parts infront of me so that's mostly guessing.

Thanks benthe8track ........ Steve

[5th element]

If space is a premium, there is always the option of putting the crossover in a pretty little box behind or to the side the cabinets.

[JonMarsh]

If space is a premium, there is always the option of putting the crossover in a pretty little box behind or to the side the cabinets.

GF would very much like to avoid that scenario- this is also necessitating some rebuild on the Isiris- in only a few things, She Who Must Be Obeyed has spoken, but this is one of them. :W

Otherwise, she's being very flexible- after all, she's been very reasonable about the musical gear, including the organ with Leslie Tone cabinet and my Marshall stack going from a half stack with one head to a full stack with 2 plus a Line6 POD HD Pro X. Most women would never even let the basics loose in their living room....











So, I need to package crossovers inside the speakers... somehow! :lol:

[5th element]

Hehe, but when you start playing and she gets to listen with pride it's all worth the space it occupies

[JonMarsh]

Scheduled Deliveries...

Well, my shipping timing worked out!



This isn't everything, have some other parts at home to pickup Saturday AM, but it's a lot less intimidating space wise than the Isiris parts dump!

But chuck this into a storage bin and there's more weight than you might expect...

Anyway, off tomorrow to the Livermore location to pick up parts and complete some other tasks, then back here for the cabinets. Also got a little bit of trim patch epoxy work done this evening. It's been a long week...

tomorrow having dinner with daughter and her fiancé with my GF - to celebrate their engagement- looking forward to that.

[JonMarsh]

Large sheet schematics printed, parts picked up from the "Livermore facility", sundry's and tools furthering todays construction efforts picked up, geez there's a lot to do when you're working from two locations!

If all goes well today, the last thing I'll be doing will be the backside epoxy coat for one of the cabinets- flipping it over tomorrow and doing the rest!

Also have a sheet of phenolic to mark to size and try crossover layouts on... gonna be busy!

[JonMarsh]

Trial Layout

Well, been a busy morning and early afternoon.

I attempted a trial layout based on the assumption of a hollow base similar to the one for the original Ardent, the outside dimensions of the base about 3/8" in from the cabinet bottom, and likely made of 1x3" maple as I used for the previous one. On that basis I made a paper template of the available space and using components I've selected attempted a trial layout.




A few notes relative to the schematic above- I've turned the 68uF C6D into a 47 uf + 22 uF; C3 is now a Superior standard 22 uF, single cap.

Floral backdrop is optional for the final build. :B

It looks doable to me.

I'll also prepare a midrange layout that fits in the existing rectangular cutout in the bottom of the cabinet, with small daughter boards for the woofer and tweeter crossover, which is what I expect you'll want to use if you go with the existing bases.

[dar47]

Well I know I would get dizzy trying to follow the schematic and solder that correctly but I'm not a "sparks and wire guru" like you. Great progress.:T

I think I'm following the 2 or 3 board path. I'm still in a holding pattern waiting for the exchanged veneer to arrive so I'll just live vicariously through you for a while.:rofl:

[JonMarsh]

I'll do my best to prepare component based layout guides with wiring overlay like I've done at times in the past- no need making this harder than necessary. I hope I can keep this momentum going. I also unboxed and unrolled the veneer, looks OK, though nothing as fancy as Ben's!

I have a few more caps and resistors to order, stole some parts from a first gen Isiris crossover- GF and the pocket book approve of recycling expensive caps! :B

[JonMarsh]

One cabinet is now epoxy coated on back, top, and sides. Materials purchased to try out a base construction next weekend like the old ported Ardent, but without the port and with a crossover built in. Crossover build will be tested separately first! And balance of caps an resistors are now on order.

Time to do laundry.... :W

[5th element]

Last time you did the laundry I seem to remember you getting more loudspeaker stuff done

[JonMarsh]

Doesn't always work that way! :W

I did get some phenolic board on order from my favorite eBay supplier for the crossover bases and for the cover/cap for the base assembly (which is actually towards the bottom, i.e., floor). And found maple 1x4 *(actually 0.75 x 3.5" of course) at my San Ramon Home Depot for the outside shell of the new bases; will have to bring my DeWalt DWS780 over to GF's sometime this week, too.

If things go OK, tomorrow night I'll flip that one cabinet over and epoxy the front in prep for veneering. The other cabinet with drivers mounted I'm leaving as is, hope to get a test crossover built by next weekend, and see if I'm on the right track. Though I was thinking about just building the crossover right into the new test bases, that would mean I'd have to have the test bases completely fabricated before I could test crossovers. So that plan was modified to include a 1/4" phenolic base plate again for the crossovers.

The trick to getting this done will be interleaving steps that need setup on one part (like the epoxy coating) with active work on design or construction of another part, and not wasting time disassembling and reassembling for testing... I'm going to take a stab at making a really detailed plan in Hit List to see if I can get all the task timing to work out. I'm really happy, if slightly surprised, that the way the crossover direction has gone, it looks like I can pack it in the base footprint. That will make any other form of construction easier, too, of course.

I'm already thinking about demo material to put together, and loading up an external hard drive for the M50 network player with some high res material, and wondering if I can find time to finish the rubidium oscillator and get the DCD8 checked out in the digital signal path.

A lot to get done in the next month and a half, good thing I'm taking off 4 days around the Easter weekend to free up some more work time! Hope nothing comes up at work to kill that- things have been very involved and tense on this project, not in the smooth sailing point that my management thought we'd be by this time.

[JonMarsh]

For once a totally screwed up day at work actually resulted in me getting home earlier, so some clean up sanding on the first part of the epoxy coat was possible, and the cabinet is flipped and ready for coating the top- though the room it's in doesn't have enough light to do this kind of work well at night, I remembered my 3800 lumen LED flashlight (no, that is not a typo- uses three of the highest power new Cree bright white LEDs) and I should be able to point it up to the ceiling for the lighting I need while working 10-15 minutes...




It uses four of the 16850 Lithium Ion batteries (3.7V each- looks like a AA that went through the opposite of "Honey I shrunk the kids".)

If I can get that done, it will have plenty of time for this cabinet to set up before Saturday, and I can start veneering that cabinet this weekend. (The other still has the drivers mounted in it for testing, and hasn't even had the base level sanding yet). The rest of the plan is building a test crossover if the Phenolic board and rest of the parts come in on time. Either way, I've got the work hopper front loaded...

[5th element]

That LED light is bigger than it looks. I put two of those Li-ion style batteries in a pair of active bluetooth loudspeakers I made and they last ages in that.

I'm assuming that we're talking the MK-R series? If it does give 3800 lumen, even with LED efficiencies the batteries can't last that long. You'd be looking at around 35 watts total consumption for that amount of light, the thing should only have a total up time of a little over 1 hour if you're lucky. Does that sound about right? I'm not questioning the product, but LED lighting is my second hobby next to audio and I'd imagine that the case would get pretty dang hot too.

[JonMarsh]

That LED light is bigger than it looks. I put two of those Li-ion style batteries in a pair of active bluetooth loudspeakers I made and they last ages in that.

I'm assuming that we're talking the MK-R series? If it does give 3800 lumen, even with LED efficiencies the batteries can't last that long. You'd be looking at around 35 watts total consumption for that amount of light, the thing should only have a total up time of a little over 1 hour if you're lucky. Does that sound about right? I'm not questioning the product, but LED lighting is my second hobby next to audio and I'd imagine that the case would get pretty dang hot too.

I think your numbers are right in the ballpark. That's why they make these out of solid aluminum billets, I suppose! I have some smaller versions with one emitter and battery for emergency use in the cars, and the house.

I'm gradually changing over all my GF's lighting to LED (a hobby of mine, too!) but that process has just started; going for high CRI devices, because of my interest in photography and image rendering.

[5th element]

I go for the high CRI devices too, the light is just a lot more pleasant that way. CREE's more recent LED arrays come in guaranteed 93, average 95 CRI options and the light from those is very nice for room lighting in the 2700k CT. Years ago the LEDs themselves weren't quite as good and going high CRI meant you paid big time in terms of maximum light output. Of course you still pay a large hit in going from average 80, to average 90 or 95 CRI, but the end product efficacies are so much higher now than they used to be that going high CRI actually makes some economical sense.

I use LED lighting in the workshop, my electronics work room, the main listening room and I have recently fitted LEDs in another room too. Going from the 80 CRI LEDs to 93 in the listening room made the atmosphere in there far nicer. The last room I converted was replacing halogen fillament bulbs where the LEDs actually ended up giving a much nicer light, use significantly less power and more importantly, don't keep blowing! The main users of said room are very happy with them as they are considerably brighter too.

[JonMarsh]

That is THE way to go, IMO. I've been excited about LED lighting, and our company makes semiconductors for that application area (I did some front end product definition work all the way back in 2006), but it's really relatively recently that availability and quality and pricing of products is finally coming together...

[TEK]

Hmm, maybe this is the forum to ask why my LED spot lights cant be turned off...
They just starts blinking when trying. Having 3 zones, 4 LED spot in the zone that will not switch off the lights (quite new house, almost all main lightning's are LED).

[5th element]

That is THE way to go, IMO. I've been excited about LED lighting, and our company makes semiconductors for that application area (I did some front end product definition work all the way back in 2006), but it's really relatively recently that availability and quality and pricing of products is finally coming together...

The pricing is the key factor. Back a few years ago I started to get into LED lighting and at the time CREE were promoting the MX3 series. In high CRI they were terribly inefficient and cost around £1.80 a pop. A couple of weeks ago I did another design using similar power LEDs (1 watt) from the XH-G series where their most efficacious flux bin, in high CRI, cost around £0.35 per LED. The price reduction is crazy and CREE seem very keen to push prices down. One thing that's really nice with the low LED prices on their lower power LEDs is that it is easy to create a lamp with lots of LEDs which increases the efficiency even more and creates a more uniform spread of light. Back when the MX3s were first introduced that kind of approach got crazy expensive very fast. The MK-R LEDs are multiple die components too, having 4 per unit, so your torch does in fact have 12 individual LED dies inside, which is probably where the MK-R gets its really nice performance from.

Hmm, maybe this is the forum to ask why my LED spot lights cant be turned off...
They just starts blinking when trying. Having 3 zones, 4 LED spot in the zone that will not switch off the lights (quite new house, almost all main lightning's are LED).

When you say cannot be turned off, do you mean you cut power to them completely yet will flash every now and again?

I know that some LED lamps cannot be dimmed and will start to flash as their drivers start to power cycle, but I don't think that's what you are trying to get at.

On some lighting rings, even when everything is turned off, through induction, small currents will flow through the wires and end up charging the power components within an energy saving bulb, this will cause them to flash on periodically. I know this occurs in CFLs, as it happens all the time in our house, so I am assuming it could possibly happen with LEDs too.

[TEK]

I think it is the latter that is the reason.
It's when turned off. Hope the firm that installed them will figure out a solution.
A bit supriced that they are having issues figuring this out - it's kind of badic functionallity ;-)

[5th element]

They probably use cheap drivers or something inside. Most things do go with economy based driving solutions rather than picking a nice fully featured driver with under voltage lock outs etc. What I am thinking might perhaps happen is the inductive currents allow the device to switch for very brief periods of time and this puts a small amount of charge into the output capacitor. LEDs have a very steep voltage curve, so will only start conducting current once the voltage across them reaches a certain value, but once it does the current they conduct shoots up very quickly. This would mean that if the output capacitor was charged to say 12 volts, hardly any current would flow, meaning it doesn't discharge, then when the next charging pulse comes in, it might reach 12.5 volts, but this would be enough to get the LED array conducting and as the current vs voltage curve is very steep the excess charge discharges very quickly causing a very brief pulse of light.

If that's what's happening then a small bleeder resistor across the LED string would solve the problem but it would also reduce system efficiency. If the resistor only needed to be quite large in value then this would only be a tiny loss. Bleeder resistors are often used across large capacitor banks in power amplifiers, and the like, to ensure that the cap banks are fully discharged after the unit is powered off. This is usually done as a safety feature as in th event of a malfunction the load can end up disconnected from the cap banks and stop them from discharging. Left like this a cap can store charge for a very long time and could be dangerous to any service personel, either qualified, or unqualified, so the small power loss is deemed acceptable vs user safety.

[JonMarsh]

Mmmm, mixed up some epoxy, and while listening to the Lorde CD I bought at Starbucks this AM got the front panel and top coated, and the rest of the sides.

I SHOULD be focused on the crossover first article build this weekend, but I "might" have time to try some veneering, starting with the back, then I think facet bevels and front, then sides and top. That would be exciting... :B