Well, many months later, not only I found the factory, I got them to improve it!

Nothing was done to the drivers so the excellent tone still remains but the frame has been improved upon. From its initial stamped frame basket, it’s now an alloy cast frame.

Big deal you ask? Yes, IMHO it IS a big deal!

Hear me out first. Over the years I have played with all sorts of speaker drivers. My hifi journey began with a PSB bookshelf which uses Vifa and Scanspeak drivers. When I went into the world of low powered amp + high sensitivity speakers, I got a pair of Hammer Dynamics which was really pleasant to listen to.

Then later, I got into the amazing world of Coral drivers and I played and lived with so many of them, all the way until the top of the range Coral Beta series.

Today I have moved even higher up the chain (and my finances further down the red line) with the amazing, but expensive, Feastrex drivers.

So what have I learned all the way?

You can distinguish the top of the line, the best sounding drivers, in a company’s line up just by looking at the frame — the usage of alloy cast frame.

Huh? What’s the big deal?

Not only an alloy cast frame cost more than stamped baskets, it’s structurally a lot stronger too. And this translates to lower distortion especially at loud SPLs.

Besides if you have been in audio for a while, you also know that one of the first “test” and audiophile does to an amp chassis or loudspeaker enclosure is to give it a little knock with his knuckle. Why? To check if it is sufficiently dampened and will not “ring”.

Hey, ever notice how does a diyer tweak his speaker drivers?
1. dampen the frame with bitumen.
2. dampen the frame with rope caulk.

For what purpose? To strengthen the frame as well as dampen the frame from “ringing”. And stamped frames will ring! A gentle tap and you could hear it go “tinggggggggggg”….

All this is in theory but we have listened to the prototype and it’s bloody obvious it’s a huge improvement!

Full specs of the drivers can be downloaded here.

When I was at the factory, I was shown this excellent 1″ {jcomments off}silk dome tweeter. The build quality is really something! Puts many of the regular offerings to shame. And I was told this silk dome tweeter sounds really excellent. Some companies take this product from him then mark up 10x to sell. Hmm…

Took some back and listening test shows it’s really good!

From now till 31st December 2010, all 3 drivers will be at a special introductory price. Get them quick!

The post Reintroducing the Merrill DCA fullrange drivers! appeared first on diyparadise.

Sophia Rocks!

//

IMPORTANT NOTICE

We have stopped distributing the Jordan line. 

That said, we are now developing Sophia 2 but using some other diver. Stay tuned!

Hey, hey mama said the way you move, Gon’ make you sweat, gon’ make you groove.Led Zeppelin – “Black Dog”

Intro

So can your loudspeakers make you groove to Black Dog?

OK, whenever I write about the awesome fun we have here with the Hedlund Horn, Spiral horns, (and more horns to come) I always get emails from folks all over the world, asking for more details.

“How does it sound?”

“Really so good?”

“What do you mean by effortless, organic, natural bass?”

The fact is, if possible, I’ll pool together the resources to build a Hedlund Horn for everyone of you. But logistics is a nightmare here. To ship a pair of 60+kg behemoths isn’t most folks idea of fun… If your idea of marital bliss is that of your wife allowing you to watch the Super Bowl with your buddies, then try convincing her of horns, horns and horns!

Yes, you know we are horny with horns. Forget about bass reflex, sealed box, transmission line, TQWT, Voight pipe, open baffles, your closet, your car booth (yankees call it trunk)… If you haven’t listened to a properly built horn, you are just kidding yourself.

Sure you are happy with the sound right now, but I know (and you know as well), there’s something better out there…

So the idea is, why not build speakers small enough to fit inside a Fedex 10kg box? We could ship to anywhere Fedex will go. We could now spread the joys of a horn speakers. Comprehende?

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It’s been a Long Journey

To be honest with you, various enclosures were tried before settling on Sophia.

Started off first with Jordan’s recommendation of a 7 liter bass reflex box. Spent quite some time adjusting the port as we are using resonance to help fill in the bass (that’s bass reflex for you). See that port sticking out there? Unfortunately, despite playing with it for so long, I couldn’t get it to sing satisfactorily. When the bass notes come in, you get a horrible b-o-o-o-o-o-m-m-m-m-m-m… This is the nature of bass reflex. Tried positioning, adjusting port depth, port size blah blah blah

Sorry, ain’t no peach.

Then I made right decision (how often can I say this?)

I passed everything to Gabriel.

As you should know by now, Gabriel is no ordinary diyer. He’s an EVIL diyer with a fetish for speakers. Nope, not regular boxy speakers but horns, horns and horns.

As far as evil diyers go, this guy ranks very high. Boy, he was playing Black Sabbath when I called him!

Gabriel took a look and said he’ll handle it. And this is what we have here.

The Jordans are now playing in the previous box but with an addition of a spiral horn. The previous port has been covered.Oh yeah, now we are courting some mojo here. And no more mood-killing b-o-o-o-o-o-m-m-m-m-m-m…

But wait, surely there’s more! More studies, experimentation later, and we now have a very unique horn loading system. As you know, in this age of Google, if we don’t give this horn loading technique a name, surely it’ll disappear into oblivion. So we’ll call it, the SeTH horn.

SeTH

Seth? Yup, Stairway To Heaven.

No kidding bro.

It’s not a simple horn, it’s not a bass reflex, it’s not a spiral horn… it’s a SeTH horn. And thus Sophia is born.

That’s the horn mouth at the top. Don’t place your coffee mug there!

Vital Stats

Driver is of course, the famous Jordan JX92 which already retails for around USD350 a pair. Enclosure is made from solid wood. 100% Malaysian nyatoh. Medium hardness but with an attractive grain. Height 11.5″, Width 7″, Depth 9″. 80Hz to 20kHz. Usable output down to 60Hz. This baby, coming from such a small box!

I want one!

When it comes to pricing our products, we want to be fair to everyone, and of course, ourselves as well. Since we are dealing with hardware here, the selling price should be at least 3x of cost price. Since this Jordan baby ain’t your typical USD30 driver, pricing Sophia isn’t an easy task.

And then we are so bloody fussy. If we just use plywood, or MDF, things would have been simpler — for us. But not for you sonically speaking.

Then I searched around the net and to my dismay, MDF bookshelves using the same Jordan drivers are going for USD2000 a pair!

Further search shows MDF bookshelf kits using USD30 drivers, crappy crossovers selling for USD500 and above. Hey, what kind of world is this?

Well, we are NOT going that route. We’ll try with an introductory pricing first.

So before we change our mind, and before we recover our sanity, grab Sophia first…. at only USD800 a pair.

Hee hee, don’t know about you but I better go now. Sophia is calling. She rocks and she digs Led Zep!

The post Sophia Rocks! appeared first on diyparadise.

Coral Speaker Drivers

Clockwise from top left: 8A-40, Flat 8, Flat 6 and Beta 6

I’m sold out on ALL Coral drivers. Whichever driver is still available on sale will be shown in the e-Store, so do check out there.

 You could also find relevant Coral information on my Flickr page.

And on the seventh day, God created Coral Speaker Drivers.

Okay, okay, I’m full of bull here but these are, in my unabashedly unashamed opinion, one of the best speaker drivers around.

Rear view.

First things first, please stop writing me to enquire about Flat 8 drivers as I have sold all of them. No more. Finito. Finished. If you missed the boat, don’t be slow again! [If you have to ask me about availability of the 8s, give me your address first, so that I could drive to your place, and clobber you to dead with my pair of 8s.]

As you may still not know this (where have you been?), the Coral Audio Corporation has ceased operation in the mid-80s. I was told they were bought over by Mitsubishi Corporation. Which must be a sad day for the audio world as these wonderful drivers made more than 25 years ago are not only beating the shit out of MOST contemporary drivers TODAY but also amazes us at how well they withstood the test of time!

If you have no idea what how long that was 25+ years ago, consider this:
The King of Pop was Black.
US of A has a former actor as the President.
The British PM wore a skirt.

Today, we are not sure of all three!

Considering back then, without the aid of Computer Aided Design, it was really marvellous speaker drivers of such quality was designed and manufactured. I’m sure you must have read all the problems with single drivers on other forums, like lack of bass, thin-hollow sound, rising frequency response, surround needs changing every few years.. Plus all sorts of tweaks to improve her performance… Well, I don’t find a need for all this work! [Though adding a phase plug did bring an improvement.]

Now isn’t this amazing?! How did they do this back then? What has 25+ years of technology and R&D later give us? Boy, I sure wish I could talk to a former Coral engineer to learn more about this amazing company!

DIY Paradise has been extremely privileged and grateful for the opportunity to discover this warehouse of a former Coral distributor, and as such, have been selling these full range drivers for the last 2 years. To date, I have sold over 50 pairs of Flat 8s and 60 pairs of Flat 6s! Imagine New Old Stock vintage speaker drivers!

Differences in cone, whizzer and surround construction.
Left to Right: 8A-40, Flat 6, Flat 8, Beta 6.

So grab them while you still could!

Flat 8. SPL 95dB. 40-20000Hz.   [NO LONGER AVAILABLE]
Flat 6. SPL 92dB. 45-20000Hz.   [JUST SOLD OUT! Have some B-stocks though. Please write to enquire.]
8A-40. SPL 93dB. 40-18000Hz.   RM400 / USD115 a pair
Beta 6. SPL 93dB. 40-20000Hz.   RM1600 / USD460 a pair

Without a doubt, the Betas are the flagship models. The basket is diecast, instead of stamped. The ribs reduce reflection and look at the mojo binding posts!

Enclosures
I have had the privilege to listen to various Corals in bass reflex, sealed box, TQWT, spiral horn and the Hedlund horn cabinets. Out of all these, it is without a doubt the best sound came from the Hedlund horn. The spiral horn is pretty amazing too and it sure doesn’t take up much space! If you aren’t horny, here’s some enclosures.

Some of the designs I have played with.
Beta 6 in Hedlund horn, Double Flat 6s, Waily’s Flat 8 (i built this too), Flat 6s in Spiral Horn (i fitted a phase plug).

Feel free to write me if you want your own spiral horn for your Corals.

Search more info on Coral speaker drivers on the Net.

The post Coral Speaker Drivers appeared first on diyparadise.

Of these, when it comes to speakers, there’s the “chop up then assemble” approach of multiway speakers and there’s also the KISS (keep it simple, stupid) path. The former uses 2 or 3 or more drivers with each of them producing a certain range of frequencies, and engineering them such that the blend/integrate seamlessly into a coherent sound. This way, a full bandwidth of 20Hz-20kHz is achievable. The latter is more of a purist’s approach where a single driver is asked to do EVERYTHING, ie produce the whole frequency range. More often than not, they will do a certain frequency range (usually midrange) extremely well at the expense of the top or bottom end. Typically, these single drivers have frequency response that begins at 80Hz and goes all the way up to 16kHz.

More important than frequency response is the crossover where 2 drivers integrate. A tweeter that cuts in at 3kHz is going to introduce its own phase shift at this frequency region. Unfortunately, our ears are most attuned to the narrow 1-4kHz frequency region. God made us this way so that we would learn to listen to each other better (and talk less). Yup, most of our vocal range is in this tight band. Otherwise, how can you hear your wife when she screams at you over the din of a lively party?

“If our ears are most sensitive to this region, it would be great if we could have a coherent voice (read: no crossover) here right?” Right again, and this is what single driver promises.

My approach to audio nirvana is simple, go for the fundamentally right, rather than start it wrong, then correct it later. And it is my belief that single driver speakers have them right. That said, my speakers are not really single drivers… Read on.

In my quest towards audio nirvana, I stumbled upon single ended triodes and realized that they are fundamentally right, just like single driver speakers. Thus I began to look for my Holy Grail…

I first built a SE amp, a 0.7W Darling Class A single ended beauty that REALLY subscribes to the KISS approach. But 0.7W is too much power for most speakers (yeah right) and so the criterion for my speakers are: high sensitivity and single driver.

Let the race begin…

I searched and searched on the great World Wide Web and found that back in the old days, the Goodmans and Tannoys were already doing this right. Word has it that the Goodmans Axiom 80 is the BEST full range single driver ever made. Unfortunately, since they were first in production in the 50s and no longer made today, their drivers have attained “vintage” as well as “cult” status. If you see anything with these pair of words accompanying them, you know you need to break the bank to acquire them. I really hate to pay more than USD1k for a pair of drivers older than I am. Also, that much money but no support? Likewise with the Tannoy Reds and Golds…

Zip to the 90s and the choices are Diatone, Fostex, Loth-X and Lowthers. The Diatone at 92dB is not sensitive enough for me. The Fostex and Lowthers all share the same problem of puny bass, plus I’m never sure I like their treble. As for the Loth-X, I haven’t heard enough of them to form an opinion and they don’t sell drivers for DIY or do they? Lowthers don’t come cheap. Acquiring the drivers alone leave me without dough for everything else. Sorry, I can’t go without food… And plus the added disadvantage that speaker cabinets for Fostex/Lowthers need to be the backhorn loaded type where there’s lots of foldings inside the cabinet. Too complicated! Too many places to go wrong! Remember KISS?
I see the light!

I soon found out that a humble company in New Mexico, USA, is also stirring the same pot! The Hammer Dynamics Super 12 is also sold direct from the factory. Which means to say, this is the best price you can get as there’s no markup on the middleman side but the downside is, you can’t audition one. If you want to listen to one, you better build one, unless you are lucky to find a buddy with this speaker nearby. Since there’s none in Malaysia, I decided to put my money on the line…

The Super 12 is not a true single driver. The 12″ driver covers from 45Hz to about 10kHz while a super tweeter takes over from 10 to 22kHz. Note that the midrange, the critical 1-4kHz range is still done by a single driver. Plus it’s 97dB sensitivity and benign impedance plot, quickly wrote itself into my books.

Note speaker wire running out from port. They are soldered directly to the crossover. Best binding post is no binding post. (actually too lazy to drill some holes…) A few months later, I got my speaker kit. The kit comes with the 2 main 12″ drivers, 2 super tweeters, crossover components and a detailed construction manual. Since I can’t even hammer a nail straight, I decided to leave the woodworking to the experts but the cabinet is actually very very simple. No foldings anywhere, just a box with 2 holes to mount the 12″ driver and for the reflex port. A local carpenter briefly got the cabinet built per the instruction manual. Built with 3/4″ MDF, the speakers came up to 48″ high and a footprint of 14.5″ by 14.5″. Quite a big box! Oh my God! I didn’t anticipate it to be this big, but it is.

It’s “nyatok” laminated as well for improving Girlfriend Acceptance Factor (GAF). This being a DIY project, you can paint the your speaker anyway you like. You can formica laminate them and spray metallic blue! Or shades of various colours for “the colours of Benetton” look… Be creative.

Anyway, after fitting in the drivers and soldering the crossovers, I began to play music. The sound was fast and very lively but sounded “stiff”. Audiophile ritual of “break in” commences… This point in time, I played them without any damping material and left the rear baffle opened. The front, side, top and bottom baffles were all glued together. The idea of having a screwed on rear baffle is to facilitate experimenting with damping material. The Hammer Dynamics manual suggest a very unique combination of bubble wrap for damping material and packing peanuts filled to the brim of the reflex port. Huh? Bubble wrap and packing peanuts? Got to be kidding right?

Not easily swayed by kiddo stuffs, I bought some carpet felt and proceeded to line the inner walls. Played music and… my jaw dropped. What a horrible sound! The sound was considerably cleaner and clearer (more “hi-fi”) than before but the magic midrange has been sucked out DRY. Hey, this can’t be right? What happened? Where is my mojo? This point in time, I decided to do the most logical thing… Read the manual.

Humbly, I refered back to the manual and the humble bubble wrap is suggested. Oh well, I have some lying around, so why not? I ripped off some felt off the side walls, replaced them with bubble wrap and played music again… Mucho better! Huh?! Out goes more carpet felt, in goes more bubble wrap and it just gets better and better! In the end, no more carpet felt and lots of bubble wrap. Crossover buried under packing peanuts.

guess the lesson is:

You macho men reading this, BEWARE! If you subscribe to the saying that “Real men don’t read manuals”, speaker building is not for you! The manufacturer has spent lots of blood, sweat and tears to get their product to sound right, so they know what they are doing. Don’t second guess their design. If you modify the design and the sound is different, this is YOUR design! Not theirs!

Okay, after eating this humble pie and swallowing my pride, I got my midrange magic back! Yippee! Kudos to Hammer Dynamics for coming up with such an excellent product! Kudos to the excellent support given throughout my journey! Kudos for the bubble wrap! (pie on my face!)

After playing for some time, I took up a friend’s (Kenneth Lau) advice and got myself some nice speaker spikes. Go to your local hardware shop, ask for plumbing bobs. They come in 100g to 300g sizes. I took the 100g ones. Slap on some Blu-tack, mount them to the base of the speakers (3 on each speaker please) and you now have some nice classy spikes. By the way, it’s called “Kenneth’s cheap speaker spike tweak”. “Kenneth’s cheap speaker spike tweak”. What a mouthful!

Damage:

Hammer Dynamics Super 12 kit     RM2500+

Speaker cabinet                          RM400+

6 pcs of plumbing bob                  RM15

Blu-tack                                      RM5

Bubble wrap, packing peanuts       RM0

Lesson learned from this project : PRICELESS.

Credits:

1. Hammer Dynamics for coming up with a great product. Affordable, great sounding, high sensitivity speakers. And also the excellent support/customer service, second to none!

2. Mr. vt4c for helping in acquiring the speaker kit.

3. Mr. Tan Ah Ban. Carpenter who built the cabinets.

4. Ken, Kenneth for listening and commenting on the speakers. Thanks for helping “mr. tone deaf” here.

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