Blood, Sweat, Tears and a Bloody Tan
a. k. a.
How to Drive Your Wife Nuts


Congrats Mr Jan Hedlund for such a wonderful design! Mucho gracias, arigato, merci beaucoup, vielen Dank, thank you very much!

Thanks a lot too to Master Craftsman Gabriel who really has wonderful hands with wood!

Now, you may not know this but I have been really lucky. I mean really really lucky. I have been fortunate enough to listen to the Coral drivers in various enclosures. Open baffles, Sealed box, Bass Reflex, Mini-Array, TQWT, Spiral Horn and now, the Hedlund Horn. Each has its virtues but for sheer quality, the last 2 deserves special mention.


Why so? It's a belief that paper drivers need special tender loving care, just like your long-suffering (in my case) better half. When a driver pumps out sound, there is a reverse wave that goes into your enclosure. If you don't take care of this sound waves, it'll wreack havoc every where especially when it bounces back to your driver and thus distort the intended sound. So how you deal with this backward waves in the enclosure, determines how macho you are! And when you have successfully dealt with this rear wave, not only your bass notes improve, the mids and highs improve as well! As there's less "junk" to destroy everything now. Comprehende?

And this is where horn designs are so highly prized! Due to the expanding volume from driver location to horn mouth, you now have a mechanical "amplifier". The rear waves have an easier path to "get out". There's a lot more theory than this but my simple mind only permits this. : )

So Gabriel suggested building the Hedlund Horn and he helped me built it. Actually, you can almost say he built it! Parts where I "contributed", he needed to do more work to undo the damage! I better stick to soldering...

Macho men only need these tools to build...


When we started building, I envisioned the smooth curves will make a baby with high Wife Acceptance Factor. However, after it completion, this baby has grown to a monster! At 6 feet 7 and weighing almost 60kg, it's no fun to carry around!

Despite the horn length, the Hedlund doesn't go below 50Hz. At least that's what my measurement shows. 50Hz is still strong but below that, it drops like a bomb. That said, who cares about quantity when you have such quality! Listening is an experience itself!


Coral Beta 6
The Coral Beta 6s are no ordinary drivers. Designed more than 25 years ago, in my books the best speaker driver listened to! Listening to the Betas in the spiral horn reveals the best mids and highs I have ever heard! The level of detail and ability to convey the slightest of nuances in well recorded material is unmatched by any other drivers I have played with. With poor recordings, you don't stand a chance though. Thus, With Great Drivers, comes Great Responsibility. Build a crappy amp, you are going to suffer. Build a crappy DAC, you are going to cry.


Thus we didn't mind suffering in building the Hedlund for the Coral Beta 6. There's definitely our blood and sweat in there! I suffered so many cuts and bruises and now the scars suggest I'm a veteran of many squabbles. So stay your distance ok? Tears came when we listened to her! Either tears of joy or tears of despair and fortunately, ours is the former. The tan? Well, no thanks to our Malaysian sun...

The sound?
Don't ask! Build it yourself! Ha ha! Anyone who doubts single drivers can do bass opt to listen to the Hedlund. Although she doesn't go lower than 50Hz, the quality of the bass is beyond compare! Fast, natural, distortion free and NO BOOM at all! In comparison, bass from non-horn designs sound "constipated", sound "forced"! All this while maintaing the brilliant mids and highs of the Beta! Also, one of the pet peeves most folks have with single drivers is the "lightweight" sound, particularly the lower midrange. Fear not now folks! It's not the driver's fault but your enclosure! Male vocals have never sounded better!


The System as of March 2006

CDPRO2 feeds Monica2 with Grounded Grid tube gain stage, feeding Charlize, then the Beta 6s in Hedlunds.


Monica2 in GG with Amperex 5842s. Will be trying other high transconductance tubes soon!
Note I hate RCA sockets so am using XLR now.


Charlize in a simple Hammond box.


Will stop here. Got to go listen to music! (And make amends to my wife!)