[greenbird]

Whoever said that I wouldnt be saving much money over buying them ready made was right... the amount of tools I need to get in order to do this properly is amazing!

4 F clamps @ $70 ... found them at supercheap auto for 1/2 the price seconds after I bought off ebay :-<
3 90 degree clamps @ $20
Router @ $80
Flush trim bit @$17
45 degree bit @ ~$8
Straight bit @ ~$8
2 standard audio caps, 2 MOX resistors @ $40 all up
25mm MDF $80
Biscuit joiner $~90
Biscuits $7
10m speaker wire $17
wire strippers $9
----
$446
----

thats on top of the $120 for the amp and PSU and $400 odd for the drivers, $160 for high grade speaker caps, cloth, spikes, binding posts, screws and other odds and ends from parts express. Looks like I blew the budget and havent even painted them yet.

Will make a circle router jig out of thin MDF that I had lying around.

As my drivers will be covered with speaker cloth to protect them (from prying little fingers - would have preferred to leave the drivers exposed, but I'm sure they would have been jabbed before they were a week old), won't rabbet the driver holes, and so can save a little by not having to get yet another crazy expensive router bit.

Cut up the MDF this weekend (weighs a ton), one large sheet had just a smidgen less material than what I needed, so need to get another sheet - not too upset about this, as I stuffed up the cuts a little on two of the panels and anyway, I'll make some side tables for the loungeroom afterwards with the offcuts - should be simple after this effort.

As a positive, played around with the tripath amp and connected both of the old pioneer speakers and listened to them at pretty high vol while the wife was out - given that the pioneers are relatively low end speakers and this amp was literally *punching* out the sound, these new ones I'm building are going to be amazing!

[greenbird]

Things are progressing - very slowly, but getting there - I've come to realise that wiring the crossover and drivers will be a very, very minor task, in comparison to construction of the cabinets. Have all the parts, but havent even started wiring them yet!

Hopefully, construction of the cabinets wont be minor compared with the paint job I have in mind!

The sawbench that I've made good use of

http://www3.picturepush.com/photo/a/6014271/220/6014271.jpg

A month or so back (cant work out how to rotate on this photo hosting site...)

http://www4.picturepush.com/photo/a/6014282/640/6014282.jpg

This weekend I routed the final holes for the drivers and completed the gluing of the baffle to the frame - I used "Gorilla Glue" for this part, which foams up and closes any small gaps. You can see some of the foam on the right speaker box that got glued today and I havent routed off yet.

http://www2.picturepush.com/photo/a/6014235/220/6014235.jpg

The back panels are finished but unpainted - finally found some threaded inserts to attach the back panel, as t-nuts split the a bit of scrap MDF, I didnt want to try them on the cabinets proper. Even had to order m6x35mm hex head screws from ebay - since hardware stores are very limited in what they actually carry - its unbelievable how much I've had to order online... its just too difficult to find exactly the right parts from any local stores - and its not as if I'm not well serviced by stores - I live in metro Sydney!

This post has been edited by greenbird: 03 July 2011 - 02:51 AM

[SpaceHiFi]

Looks very interesting... Keep us posted! :D

[greenbird]

I'm just putting the clear gloss onto the cabinets over the last couple of weeks - I had a near disaster by overbalancing one of them on a bench'n'vice for painting (they are really heavy!) and it crashed to the floor, damaging the paint and crushing a corner - delayed me over a week finding a bog that would allow a corner to be reconstucted.

Come to think of it... there has been a number of setbacks along the way that have absorbed a great deal of time :-)


I'll probably get a second can of clear and then start the polish phase. The paintwork looks gorgeous.


Anyway... a new milestone. Yesterday the old man was over from Adelaide and as a bit of father/son time we built one of the crossovers from the components that have been sitting under my bed for nearly 6 months now and connected them to one tweeter and one woofer using alligator clips with the drivers just sitting on the floor.

Oh wow! They sound stunning to my relatively un-audiophile ear. and that is only using mono and 2 of the 6 speakers.

The little TK2050 amp does a great job of powering those 2 speakers - I hope it can maintain the rage when I connect up the other 4.

[greenbird]

ok - the end is in sight.

Installed the drivers and crossover into one of the cabinets today - as always, little unexpected inconveniences crop up. One of the threaded inserts that seats the nuts screwing on the back panel came loose from its epoxy glue and came out. 3 can hold it fairly firm for testing however. Its epoxied back in again and drying at the moment - takes a couple of days.

I've routed out a frame for the speaker cloth that will fit over the baffle - the rough black paint is simply so the MDF colour doesnt have a chance of showing thru the speaker cloth once the frame is on. Had to order in little ball and socket plug thingies to mount the frame - yet something else that nobody sells in Australia for a sensible price.

http://img62.imageshack.us/img62/5913/sam3704a.th.jpg

Connected it up to the little TK2050 amp and this single speaker with 3 drivers has a good deal of punch - massively exceeding the pair of the Pioneers and enough to actually make my ears uncomfortable when wound up to near full power. Every now and again at max power, audio drops out - I suspect strongly that it is the amp chucking a wobbly for some reason as dialing down the volume makes audio re-appear.

I also traced a nasty hissing sound at full vol but no signal from the HTPC to the el-cheapo DAC from China that I use... amazing how a quality speaker highlights the weak links in your system. The hiss is completely overwhelmed by any sound, so its no real concern as long as I know where its coming from - using the DAC in the motherboard instead makes it acceptable (given that its a full vol and a sound signal at this volume would be extremely uncomfortable).


Can't wait to get the second one going :thumbsup:

[greenbird]

Been meaning to post the end results here for a while... they've been mostly completed for ages, but made the final push and finished off the last grille cover only a couple of weeks ago.


I'm still happy with them overall, but I have found some limits with them - I guess I might be catching audiophile disease?

http://img593.imageshack.us/img593/9063/sam0509q.jpg

The little speakers behind it are Logitech 5.1 PC speakers used for general TV viewing.

The amp is a HifimeDIY TK2050 that I've enclosed in a little plastic instrument case - at first I was concerned about heat venting, hence the big hole... but in real life it runs only slightly warm. Lives second drawer down with the XBox360.

http://img708.imageshack.us/img708/5950/sam0495b.jpg

Because that TV unit is also occupied by a HTPC and an old xbox that my older son loves, the PSU is separated and lives behind it on the ground.

http://img443.imageshack.us/img443/2633/sam0492s.jpg

I replaced the hissing Digital Signal Processor with a Fiio D3 DAC doesnt hiss at all.

I will say is that I think that speakers have more to give than the amp wants (not can) to give it - in the sense that even with the amp volume at max, I think that the speakers could deliver more if there was more gain in the amp. I think its probably the DAC output is a bit low. The DSP seemed to be able to drive the amp and speakers to a higher (albeit hissing) volume. Maybe a pre-amp would do the trick?


Toying with the idea of building a sub next, but the only australian supplier Creative Sound Solutions parts can't say when the parts will be in.

[Dean1M]

Very interesting images and description of a great project. I have been looking for time to do some more work on the audio side of my HTPC/s and your efforts have saved me a heap of time.

I was particularly interested in your observations re amp output/speaker output and your thinking that the DAC may not be helping. I recently built a small pre-amp to help out an old system I have. I managed to improve the overall sound "volume" but my rough efforts with the pre-amp did not improve the quality much, if any.

As for catching the audiophile disease that is nothing to worry about. I used to love valve amps(still do) I even like listening to muso's who specifically use analogue gear. I thinks it's what they call an artefact of a pre existing condition. Once you have caught it you can keep it under control but it will never fully go away. :D

[greenbird]

Dean1M, on 23 February 2012 - 02:09 AM, said:

Very interesting images and description of a great project. I have been looking for time to do some more work on the audio side of my HTPC/s and your efforts have saved me a heap of time.

I was particularly interested in your observations re amp output/speaker output and your thinking that the DAC may not be helping. I recently built a small pre-amp to help out an old system I have. I managed to improve the overall sound "volume" but my rough efforts with the pre-amp did not improve the quality much, if any.

As for catching the audiophile disease that is nothing to worry about. I used to love valve amps(still do) I even like listening to muso's who specifically use analogue gear. I thinks it's what they call an artefact of a pre existing condition. Once you have caught it you can keep it under control but it will never fully go away. :D

Thanks Dean,

It was a lot more effort that what I'd initially anticipated. All of those estimates out there of whacking a pair of speakers together in a weekend are waaay off the mark. At least for me anyway. I guess if you were a master craftsman who made no mistakes and with all the right equipment, you could get the frame all glued up - but then you're only half way done.

Its frustrating to me that the windows 7 volume is obstinately refusing to go higher - a pre-amp these days in an all digital system seems to me to be unnecessary from a technical standpoint... its kind of grating on me that it might be the only way, other than changing to Linux or something.

If I do go down the pre-amp route, I'd sort of like to use a valve as well, just to make it more interesting and maybe make it a bit of a showpiece - but I'm a bit put off by the high DC voltages that they run at... although there are apparently some lower voltage designs out there, I've no idea how good they are.

[Redwight]

Over the years the Russians have remade just about every one of the old valves that everyone are familiar with but smaller to reduce power consumption, there is no good reason to not go down that path as long as you really like a challenge. Personally I have a thing for really messing with true audiophiles and tube worshipers but I'll refrain for now seeing the conversation isn't going that way. I have had a friends brother in my car dishing up some fairly serious compliments for the sound system in it, about an hour and a half later he realised I hadn't changed discs once and started ranting on about how poor the results of MP3 compression are - no contradiction at all in that is there. :arghhhh:

[greenbird]

An interesting discovery for me... I used to think that the onboard optical SPDIF that comes out of the mobo and into a DAC was fine.

But prior to dropping another few hundred on parts for a sub, I wanted to squeeze as much quality out of my speakers and system as possible.

I read around about room equalisation,etc and then mucked around with VST plugins etc - none of which seemed to make a signifcant improvement.

Until I tapped into the Windows Audio drivers (WASAPI) and bypassed the normal Kernel mixer (Kmixer) - initially this was with ASIO4ALL and then the WASAPI plugin in foobar.

Suddenly the two speakers positively *burst* into a completely new and magnificent level of quality that I'd never heard before - for the first time I could hear what the audiophiles call "Soundstage" and "Headroom" as the living room almost sprang to life.

I can't recommend trying it enough - if you serve music from your HTPC, at least give it a try. For some reason even the foobar site says that the difference is debatable - I just dont get this... on my system there is no mistake (and all the options and enhancements that kmixer offers are turned off).

[Dean1M]

Greenbird,

good to get an update on the project. Also nice that you have found
a way to ratchet things up a bit without spending a load of dough.

If you get a chance to try out some valve gear I'd definitely give it
a go. I have always had a soft spot for that warm glow and sheer grunt
that tubes can give.

I'm not knocking digital gear. It's what I use exclusively now.
But the last time I looked at a car stereo it boasted 425 watts
of power. Now if that little plastic box could actually put out 1.5 watts
I would be surprised. Conversely a Dynaco Valve Stereo 35(17.5 watts per channel)
would leave you semi conscious and bleeding at half volume. B)

[greenbird]

Been toying around with Foobar convolver and there are some impulse files downloadable for popular tube amps that should allow the music to be "tubified"

:D

this is fun.

I'm going to try and get this free software called REW from HTShack, a SPL meter and try and create an impulse file that corrects for the acoustics in my living room.