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The best DIY speaker in the world?


kye

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katattack - have you treated a driver with enabl and then compared it to the untreated driver?

I treated some mids and woofers and found the response smoothed out, but they got slow. very slow.

I don't know about you, but if music sounds 'nice' and the musicians sound like they're half asleep then what's the point? Ideally i'd like to have great tone and great speed, but they seldom come together and to my ears a ton of tone isn't worth a gram of pace or dynamics.

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Kye,

Interesting post as usual.

I wish more people on Stereonet would pursue experiments like this.

.

Have to agree with you there THOMO kye always has very interesting projects :hiccup:thumb::thumb:on the go .

I wonder how a line array of Coral Flat 5's would sound.

G :thumb:reat work Kye

CHeers

Edited by 56oval
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.......

steve, the bass is an interesting one - it's not normal bass. yes it shakes the room if you wind it up a little, and to my ears it is balanced with the rest of the spectrum, but it's very different to ported cabinets.

basically, it sounds empty. the speaker sounds like there's no bass until you get something with low frequency energy in it, and then it just renders that instrument.

if i'm honest the lowest part of it's response isn't the best i've ever heard (it's a little boomy) but it's there and it's mostly integrated and it comes for free with the drivers, and it's not objectionable. a friend and I have been on similar journeys over the last few weeks (he's just made the jump to some coral fullrange drivers) and previously he was using a high-end 3-way active system. his comments were that whilst the frequency extremes aren't the best ever, if the price of integrating them with other drivers is to lose some of the magic in the sound then it's not worth it. the weaknesses are easily tolerable because they give so much more information than normal speakers. he was saying that even in his active system the crossovers kill the magic of the drivers (and his are high-end valve crossovers) so I think that the less playing we do with these things the better.

A really honest reply to the bass response issue Kye, much appreciated. :hiccup:thumb:

Steve.

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I must admit, i'm really happy to see such interest in this project - these speakers are too good (and cheap and easy to make!) to not share :hiccup

here are some pics :P

[ATTACH=CONFIG]38959[/ATTACH][ATTACH=CONFIG]38960[/ATTACH][ATTACH=CONFIG]38961[/ATTACH][ATTACH=CONFIG]38962[/ATTACH][ATTACH=CONFIG]38963[/ATTACH]

monaro8 - this is a logical question, however my point is that actually these are the better drivers.. let me give you a bit more of a baseline. these drivers are better than all vifa drivers i've heard, all polypropylene drivers i've heard (although that's not hard), better than the focal 8" paper drivers I have (which retailed at $200+ea when they were available) and accuton ceramic mids. and for musical enjoyment they are in the same league as the scanspeak revelator series mids, the avantgard duo horn speakers, and quad ESLs. however, if you're talking about better quality fullrange drivers, then yes, i'm all ears about that too, however at this price, we can buy 8 for less than a pair of almost everything else, and having 4 per side will likely give advantages of slam and power handling that a single pair of better fullrange drivers will still likely struggle with.

katattack74 - i'd encourage a build by others.. not only to get a second opinion, but also to share some of the goodness around :P

earle - would be interesting to do a comparison between these and the fostex.. I suspect the fostex would win outright, but in value for money i'd say these are almost impossible to beat. have you heard the horn tweeters? i'd shy away from them - horns are fundamentally prone to resonances, and for the money they charge for these things you can get really nice ribbons!

thomo - yes, it's a fairly logical approach, and one I wish i'd explored 10 years ago.. would have saved myself a whole lot of money, but then again, i've had a lot of fun too :) i'm glad i've gotten here in the end though!

I find the magic of these things is really fragile - try to put anything on the ones running fullrange and the magic exits stage left instantly. that's why i've had to use the extra drivers to flatten things out. on more harsh recordings their normal response is odd at lower volumes and rip-your-ears-off-your-head at higher volumes, so they really need something to even them out. also, I suspect that the depth of the cabinet really helps too, which is something i've never tried before. the cabinets were designed as subwoofers and the panels sitting waiting assemly in the garage, so that's why they're the dimensions they are - I figured that if it didn't work i'd only have to cut two more replacement panels and then i'd have sub cabinets again. that's also why the screws don't match!

interesting point about the whizzer removal.. something to think about - if we can get away with removing the inductor I think that would be a win, although we'd be changing the cone mass too, which i'm not so sure is a good idea.

fullrange - would be interested in your impressions, I can see by your username you're ahead of the game on this kind of thing :)

in terms of an alternative to a supertweeter, you can build them without and see how you go - there is lots of high frequency energy up there, and I didn't miss it during a week of heavy listening.

JA - yes, my thoughts initially ran straight to "will more of these things be better? - line arrays!" but I think it will depend on your amp and room.. I ran these things seriously loud last night and they remained completely composed (room shook with the low stuff, the upper bass and lower mids were all physical like a good PA, medium yelling volume was completely undetectable) they had the 'bounce' that you feel when you're at a gig and the band and crowd are going off, absolutely fantastic. from this I think that they're able to produce enough volume for any listening in a small room, and sensible listening in a larger room. if you had a huge room and are an AC/DC fan then maybe more would be better, but i'd start with this :) the other aspect is that if you double the driver count then you'll halve the impedance, which makes it less SET amp friendly, and I think this is part of what makes the magic of the speaker. for me it seems to ignore most of the tradeoffs - it plays loud, goes relatively low, is efficient, is an easy load, and it's cheap!

mick35 - listening to them straight (especially in a non OB cabinet) is pretty underwhelming.. they're not flat enough as a single driver to really be palatable unfortunately. they'll also ruthlessly expose what the first watt of your amplifier sounds like, which in many (most?) solid state amps isn't likely to be that pretty.. the design can be scaled to use 4 drivers total (ie, half what I used) or doubled to use 16 total if you're willing to accept a 4 ohm load. if you're a bit wary then you could build a single speaker in the half version and see how it sounds. I found that even one channel is pretty nice - lots of depth and information.

that jaycar one might be the same driver - as usual jaycar copies altronics and jacks up the price!

whatmore - this is about as simple a DIY project as you can get - i'd enourage you to give it a go! you'd need to be able to build a box (or get someone to do it for you) - the hardest part of this would be cutting the round holes for the drivers. the electrical connections only require one part to be connected except the drivers and if you're careful you can get away with twisting wires together (or use aligator clip leads) and it would work ok. ideally you'd solder the wires together.

i'll put together some instructions with box and electrical details and upload them when they're done..

and Lo, the Straight Eight was BORN!!!!

Kye.

For the price of less than one FE206e, eight of those drivers can be had.

I'm guessing their Qts is pretty high, so a good choice for OB.

I have some nice ribbons laying around somewhere. I think I need to build a pair of your Straight 8's.

Cheers, Earle.

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kye,

just thought I would mention the other speakers...30w...coz I saw them on the Altronic website.

As far as the bass goes, being an OB set-up the bass will be different to that of an enclosure. Not DEEP thumping bass but from other OB's that I have heard, the bass "instruments" sound more real and rounded in presentation. For more deeper bottom end, if needed or desired, a subby can fill in there...it's more a personal taste thingy.

If your bass is mellow, realistic and rounded whilst still being easily audible, then depending on the type of music you listen to, it could/would be enough to please the ears. Combined with superb midrange and highs where most of the good stuff/sounds are desired (by me at least anyways) they should be exteremely nice to listen to for long periods without any fatigue.

BTW...how do the vocals sound...certain OB's tend to have a bit of 'harshness' in the vocals??

If these babies deliver a natural, airy, realistic sound which is very listenable...bring it on baby!!!

Cheers...Vanch

(my fingers are getting tired now from all this "one fingered" typing...and trying to remember how to prpperly spell the wordz)

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I don't know about you, but if music sounds 'nice' and the musicians sound like they're half asleep then what's the point? Ideally i'd like to have great tone and great speed, but they seldom come together and to my ears a ton of tone isn't worth a gram of pace or dynamics.

You're really on fire Kye! I couldn't agree with you more ...though tone is very important.

All of my playing around with different systems shown here: http://stevem1960.blogspot.com/ ...have lead me to a similar conclusion. I do like a refined sound, but like you I'm not into a polite sound either. My systems are not for everyone, but they do what is important to me, that is, they have a lot of presence and are very good at the transient edges of the music, its the attack and decay that do it for me. The midrange must be fast, free and easy with an open character (something that your C2000A driver would be good at). Its why I have tended to like point source drivers; horns; ribbons; OB and stats.

Steve.

Edited by Steve M
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OB bass would never have the "kick" of sealed bass. They are velocity source (not pressure source) and will not pressurise the room :hiccup

Whether this is a benefit or drawback is up for discussions, and may simply come down to preference :P.

I am very biased with OB bass btw.

btw. great project (I thought you gave away the Altronics woofers kye?)

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Wow nice work Kye, I think the speakers look fantastic. Facinating results too. Thats one thing that i've always had respect for is DIY Stereo builds. Every idea started off as just that, an idea. And yours has heaps of potential. Altronics sell those drivers nice and cheap. If you do a bulk buy of 20+ they come down to $11 each which is a bargain.

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56 - if you're offering to send me some flat 5's then i'd be happy to do a little woodwork!! seriously...

steve - have looked at the bass in a little more detail and discovered two things. there's not much below 40Hz (swept sine wave) and I think some of the boomyness is the cabinet. I tapped on the side panel and got a bit of boom from the cabinet. at the moment these cabinets are completely without bracing (ie, they're 5 bits of wood screwed together - not even any glue) so this can obviously be improved a good deal.

earle - yes, a high Qts.. I think these are the sort of speaker that used to be mounted in the cielings of train stations many years ago to give those unintelligable announcements.. "the next train to armidale will be leaving in 10 minutes... " :)

vanch - this might be a language thing (sound is so hard to describe!) but I wouldn't describe these as having 'mellow' or 'rounded' bass - quite the opposite in fact. the bass in these (except the 40-80Hz region with the box boom) is very fast and really punchy. if you crank them up enough then you get the PA style kick that many people love. I've got a pair of 18" PA woofers and they had great kick, so i've heard the real deal in the same room - the 8"s aren't quite there, but they're in the same direction, and certainly not something the average ported cabinet could even dream of.

vocals are very clear, but not harsh or fatiguing. these are very truthful speakers and you can play them really loud without harshness or wanting to turn it down. I think I played them a little too loud last night, as my ears sounded a bit wooly afterwards and still do now (!) but even then it was very easy to listen. you start to hear the different acoustic spaces around instruments (especially in older recordings before they replaced real reverb with electronic processing - the beatles songs are all remarkably different) and things sound more live.

not sure if you'd call it airy - to me this implies a sound without enough bass and gives the impression that the music is disconnected and floating somehow. these speaker are not that at all.

steve - as I mentioned before in my last PM to you, I think perhaps i've mis-represented by stance on tone. let me outline my thoughts.

when viewed simplistically, drivers are just a moving coil in a fixed magnetic field. the physics is beautiful, and the only barrier to fidelity is the moving mass, otherwise they'd be perfect. loudspeakers are, however, not perfect, and two significant sources of this are non-linearities in the motor system, and resonances. resonances are what cause an uneven frequency response, but they also cause significant time issues. really uneven frequency response plots indicate significant resonances, and these are a barrier to fidelity. I am used to hearing systems that have a certain standard in this regard, and I can hear time issues pretty well. this is one side of tone.

the other side of tone is the masking of information. i've heard that kondo (of audio note japan fame) said that digital was what saved tubes. I think he was right. the unpleasantness of poor digital is something no-one wants to hear, and this has spawned entire subcultures who pursue electronics that will filter out this information. they like warm sounding tubes, they like non-oversampling dacs, and they tend to like silk-domed tweeters. this is a sign that they want to add in things that are 'nice' and block the unpleasant signals already in the signal path. in my experience, the people who talk about tone are the ones that are pursuing systems that sound like drinking honey by the fireside - my word for this is "suffocating".

the goal of a system is to be as transparent to music as possible, so we get to hear as much of the music on the disc as possible. these speakers are transparent, meaning they're not removing things and adding in other nice things in their place, they're just passing on what's given to them without doing (too much) harm.

they will have resonances, but for whatever reason, these speakers with their resonances give a better end result than other speakers with their damping.

mick - it's the smallest RAAL. very nice. one of the best tweeters i've heard regardless of price.

gainphile - I would tend to disagree about the OB bass, but this could be as much about terminology as it is about sound. who knows. these things are fast, dynamic, and good to about 40Hz. After listening to the bass from these drivers for a couple of weeks I would say that ported bass, and also sealed bass, has a sound that I can hear, and whilst it's not unpleasant, it doesn't remind me of live music. I like sealed bass a lot more than ported, but both have a sound. it could be the rolloff characteristics (OBs have a steep rolloff, sealed is quite shallow) so maybe that's it. obviously each to their own, but for me, this is a step forwards :)

I was giving these away actually, but no-one wanted them. I only listened to them out of curiosity before putting them out in the council curbside collection. good thing I did!

my thoughts about cabinets are that these deserve a real cabinet and I should make the next one a lot better.. it will be taller so the ribbon can be in line with the other drivers, and so it's closer to ear height. the baffle will be narrower for better imaging (although I realise I didn't mention this - they image fantastically now.. i've got them really wide, and they project a huge image, deep and wide, but still with a solid centre. buena vista social club transports you to a different place as you'd expect from decent speakers, but it's surprising how many other recordings also have the same effect, even ones I thought were pretty sterile studio recordings). in terms of tackling the bass boom issue, i'd make the sides flare out slightly so the width at the rear is more than the baffle. this would mean that there would be a lot less box boom as there wouldn't be any potential for standing waves. i'd likely separate each driver by putting in 'shelves' that both brace the side panels as well as stop cross-talk between the drivers. this would move the vertical resonance frequency up into the 100-200Hz region where it can be damped a bit better by stuffing. i'd then brace each panel front to back with strips of MDF so that if you looked in the back it would look a bit like cross-hairs. I might also be tempted to place random small blocks of wood on the exposed surfaces to further break up standing waves. if you have enough diffusion you can almost eliminate stuffing, which is good because stuffing slows things down.

I think i'd use ply for the next ones too, then I can polish them up to look like furniture :)

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56 - me neither! I was hoping you were going to hook me up! anyone that talks about line arrays of old/rare drivers gives a certain impression if you know what I mean :)
My friends used then in different cabs ,the best cab so far was concrete spheres .

Cheers

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56 - if you have enough diffusion you can almost eliminate stuffing, which is good because stuffing slows things down.

)

When I used to make speakers, I too didn't like the way the stuffing effected the sound

Instead I used rubber car mats from auto shops, glued in place with contact adhesive

I'd check the resonance of the speaker cabinets by putting a metal fork between my teeth and feeling the vibrations, that was a bit fanatical though !

Thanks for a fascinating post and thread

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Thanks Kye for posting further details and your comments on the progress of this very interesting project. As some others have already commented, it's a DIY project that isn't going to break the bank. :)

I feel the advantage of this type of project is it's infinitely tweakable and this along with the simplicity of the original design may just encourage those whom might have otherwise shyed away from such an undertaking might just be tempted to give it a go. IMHO and IME, much knowledge can be gained by DIY projects of this kind.

Cheers,

Alan R.

(Posted from the Qantas Club Lounge - Brisbane)

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kye

how about the next model up from Altronics???

http://www.altronics.com.au/index.asp?area=item&id=C2002

Any good @ 30w

Vanch

Oops! Typical hi fi nut question...already trying to make improvements!!!????:sorry:

Hi Vanch,

With a a few minor tweaks (perhaps even none) I can't envisage any real issues. (Comment based purely on the limited info available to me on the drivers at the time of writing.)

There is an obvious difference in driver efficiency but if IIRC it's only 2dB for the drivers. The 30W driver has a fundamental resonant frequency of 45Hz which is almost an octave lower than the 5W driver. This may push the hump in the bass response Kye commented on lower down the frequency spectrum making it potentially less noticeable provided it is managed correctly.

Cheers,

Alan R.

(Posted from the Qantas Club Lounge - Brisbane)

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Hi Kye,

Just a quick few questions about the 0.05mH inductor.

By my calculations and observations the circuit represents a simple 1st order low pass filter (6dB /octave).

2 x 8 ohm drivers in series = 16 ohms. The 0.05mH inductor in the circuit makes a ~50kHz low pass filter for the two lower drivers in question.

As 50kHz is well above the drivers' capability (80Hz to 18kHz) and above the accepted limit of human hearing, is not this value a tad too low to be effective other than introducing a phase shift? Possible misprint???

Have you tried eliminating it all together, and if so what change was there to the overall sound?

Cheers,

Alan R.

(Posted from the Qantas Club Lounge - Brisbane)

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quelch - I have a stethascope purely for that, although after getting it I realised that actually just shoving your ear to the cabinet works well too (maybe better?). this kind of attention to detail of course doesn't replace the basics such as fastening drivers securely and sealing up the cabinet properly.

hi alan!

yes, I hope that the simplicity of this encourages some to try DIY - certainly it's by far the best sonic results i've gotten from a speaker, and easily the simplest crossover too.

the 0.05mH inductor is not an error, and it also is a bit of an odd thing. after arriving at that value through listening and posting it, I calculated it to be a 10kHz low pass (maybe i'm wrong here?) and wondered if i'd steered people in the wrong direction. I did however notice that there's a difference between the sound of the fullrange drivers and those with the inductor, so for whatever reason it is having an effect. it's also a less-is-more thing as well, I started with a lot more inductance and got to this via listening. of course, people can easily try other values if they're keen :sorry:

eliminating it is where I started off the design and it makes the speaker more forwards in presentation, which makes it sound a little more immediate but unbalanced at low volumes, and at high volumes it makes it feel like your ear drums are being shredded! I find a good test for things is to crank them right up - you soon know if things aren't balanced correctly :(

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Hi Vanch,

With a a few minor tweaks (perhaps even none) I can't envisage any real issues. (Comment based purely on the limited info available to me on the drivers at the time of writing.)

There is an obvious difference in driver efficiency but if IIRC it's only 2dB for the drivers. The 30W driver has a fundamental resonant frequency of 45Hz which is almost an octave lower than the 5W driver. This may push the hump in the bass response Kye commented on lower down the frequency spectrum making it potentially less noticeable provided it is managed correctly.

Cheers,

Alan R.

(Posted from the Qantas Club Lounge - Brisbane)

Thanks Al,

I just though it would be an idea to ask kye if he had tried the 30w Altronics drivers comparing them to the cheaper 5 w drivers. They are a bit more expensive but still fairly cheap overall.

What a great project...come on kye...some more pics please, any new developments?

Cheers...Vanch...icon6.png

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hi alan!

yes, I hope that the simplicity of this encourages some to try DIY - certainly it's by far the best sonic results i've gotten from a speaker, and easily the simplest crossover too.

the 0.05mH inductor is not an error, and it also is a bit of an odd thing. after arriving at that value through listening and posting it, I calculated it to be a 10kHz low pass (maybe i'm wrong here?) and wondered if i'd steered people in the wrong direction. I did however notice that there's a difference between the sound of the fullrange drivers and those with the inductor, so for whatever reason it is having an effect. it's also a less-is-more thing as well, I started with a lot more inductance and got to this via listening. of course, people can easily try other values if they're keen :(

eliminating it is where I started off the design and it makes the speaker more forwards in presentation, which makes it sound a little more immediate but unbalanced at low volumes, and at high volumes it makes it feel like your ear drums are being shredded! I find a good test for things is to crank them right up - you soon know if things aren't balanced correctly :P

Hi Kye,

As the two 8 ohm drivers are in series that gives them a combined impedance of 16 ohms. The 0.05mH inductor in series with those two drivers has an inductive reactance (XL) of 15.708 ohms at 50kHz (XL = 2*pi*f*L); where f is the frequency expressed in Hertz and L is the inductance in Henrys. At 50kHz, half the input voltage will be dropped across the 0.05mH inductor with the other half dropped across the two drivers in series with it closely approximating a 6dB drop which corresponds to the expected HF roll off of the 1st order electrical fliter in your design. 6dB is the half voltage point. dB = 20 log V1/V2 formula applies.

I don't dispute the listening results. As a matter of interest have you confirmed the inductance of the 0.05mH inductor to be 0.05mH? I'd love to have the opportunity to have a listen at some stage if that's possible. I used to DIY speakers years ago. Most projects were done on a very tight budget back then and it would be extremely interesting to hear what can be acheived today by enthusiastic DIYers such as yourself. Looking forward to reading more of your posts on this project.

Cheers,

Alan R.

Edited by Alan Rutlidge
typo errors
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Alan,

it would be good to have a second set of ears to listen to kye's speakers...not that we don't trust his observations, just another opinion.

Also, seeing that you were a speaker DIYer yourself, another experienced observation would be great.

We are waiting patiently...

Cheers...Vanch...icon6.png

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Alan,

it would be good to have a second set of ears to listen to kye's speakers...not that we don't trust his observations, just another opinion.

Also, seeing that you were a speaker DIYer yourself, another experienced observation would be great.

We are waiting patiently...

Cheers...Vanch...icon6.png

I second the motion ! (also waiting patiently ...) :(

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