November 8, 2010

Introducing the Econowave speaker

After hearing some Econowaves and various driver and waveguide/horn combinations, I have found that not all drivers and waveguides are created equal. This comes as no surprise. You might like to read about a series of waveguide shootouts which include measurements of speakers like these, and listening impressions.

Waveguide shoot out 1 >
Waveguide shoot out 2 >

Are you looking for a speaker that ...
  • is something different - not another slim floorstander!
  • plays nicely with valve amps
  • is room friendly - suits a room that can't be acoustically treated
  • knows how to rock in a way that other speakers can't
  • won't hurt the hip pocket
  • is ideal for home theatre, not simply another hifi box
The Econowave might be for you. It's a low cost DIY speaker that many are now building and talking about in the US forums.

Demo video

Read about it on the Audio Karma forum:

Econowave thread > (sign up required to view images)

or on Parts Express >

Warning: Information overload!
Don't expect to read it all in one sitting. Or 10 sittings. Read as much or as little as you like, but if you want to simply build it "monkey see, monkey do" style, then start here:

Standard version >

Deluxe version >

What about horn coloration?

If you've heard a compression driver based system before, you've probably experienced the coloration that most dislike. Earl Geddes has shed some light on the problems with horns and new designs have overcome the nasty shortcomings that many associate with horns. This is something that you need to experience.

Read about some listening impressions here >

What are the advantages of the Econowave?

1. Controlled dispersion

The waveguide maintains a flat response over a controlled angle such as 90 degrees and we aim to cross to the woofer at a point where it has a match polar response. A conventional two way with a dome tweeter and cone mid can't achieve this. The polar response will shift at the crossover. The only way to avoid the shift is to operate the tweeter down to where it has an omnidirectional dispersion. This isn't a desirable trait.

Controlling dispersion means a better interaction with the room. The econowave usually has narrower vertical dispersion to avoid ceiling reflections.

2. High efficiency

A typical two way speaker is limited to around 87 db efficiency. This tends to limit dynamics as well as output level. Power is cheap but power compression and poor thermal dynamics are limiting factors. Higher efficiency is necessary for an effortless clean dynamic sound. The econowave has around 95 db efficiency and will sound almost twice as loud at modest input levels. This difference will increase with higher power input, since the Econowave will likely have higher power handling as well due to the use of pro drivers. The raw efficiency of a compression driver is around 108 db.

3. Easy to drive load

Typical driver choices will result in an 8 ohm load, which is easy to drive. Typical floorstanders have a 4 ohm load. Most AV receivers aren't suitable. With conventional hifi speakers, one has to spend more on the power amps. An Econowave speaker could eliminate the need for an amplifier upgrade and more than pay for itself.

My plans

I may in fact build my own Econowave. If I do, it will be an active 10" version and the result is likely to become a surround speaker. The longer term plan is to build a 15" active version with the B&C DE200 compression driver and Acoustic Elegance TD15M. It's a toss up between starting with a budget version first, or simply going for the deluxe version. I'm also planning to build my own waveguides, so this wouldn't really be an Econowave project, but the design approach would be similar.

Do you want to buy one but can't build it?

You have two options. One is to source all the parts and have a cabinet built locally. The other is to purchase a Geddes kit. They are designed by Dr Earl Geddes who appears to be leading the field and is a pioneer when it comes to waveguides. If they fall within your budget, seriously consider the Geddes kits. Even if you don't buy them, at least read some of the papers.

Geddes speaker kits >
Geddes papers >

Which Econowave should I choose?

I have a couple of suggestions:
  • avoid the Selenium D220Ti and other titanium compression drivers - much better drivers are available
  • avoid the Dayton round waveguide/horn - the Pyle unit is better sounding and measures very well
  • adding reticulated foam is highly recommended, but must be allowed for in the crossover
  • even when using a poorly made adaptor, better drivers like B&C DE250 and BMS 4550 sound better than the Selenium which is intended for screw fit waveguides and horns


  1. I made some econowaves last year and very happy with them.. once I saw the light and used the Selenium comp. drivers.

  2. Thanks for that link minirig. Here's my planned attempt of Econowave with DSP:

  3. good to see! I'm following your progress on the audiokarma forum (I also just posted there as I'm upgrading my woofers to Delta 12LFA).

  4. Which combo (tweeter, horn and 12 inch woofer) would make great sound and be under 1000$.

  5. My advice is firstly choose a version that does not use a titanium diaphragm. B&C DE250 is a good choice, although it's a bolt on type and costs more, around $350 a pair shipped US to Au. You could get a pair of mids for about the same and the rest should do the box and crossover. I'd pick up MiniDSP and a cheap low power amp for the tweeter and do it active, then pick the parts you like and can get a good deal on.

    If you want to do a passive version, I don't know of a version that combines the B&C with an easy to get waveguide, but it could be there in the threads. You would have to ask.

  6. I've been searching through your blog, but I can't find why the Selenium D220 actually is not a good choice? It's quite a bit more affordable than the alternatives.

    Also, the Dayton WG's seem to measure very well. Why are they not recommended? I understand they are cheapish plastic, but can't you just dampen the waveguide?

  7. Martijn,
    The other drivers are far better. Having heard them one after the other, D220 is quite harsh in comparison to DE250 and the other drivers featured in our waveguide shoot outs. The difference is certainly worth spending more. Likewise the round Dayton had noticeable horn honk and a little more harshness. The Pyle in Australia is dirt cheap but we didn't notice horn coloration and there was less harshness. It was the value leader of the group and even worked quite well where the better drivers with an adaptor was used. It's a good idea to add some damping, but I'd suggest you start with the Pyle which I found to be a better sounding waveguide. If budget is tight, then I'd consider some of the cheaper B&C units but as a general rule I'm wary of titanium - polyester, mylar and polyimide seem to sound smoother.

  8. Paul, thanks for your reply. Too bad the Pyle and the likes are hard to obtain in Europe. The Seleniums (about which many people speak very favorably) and the Daytons are already on their way, so I'll just try and make the best of it. If it doesn't turn out well, I might try and have the Pyles shipped. Thanks again and keep blogging!

  9. Howdy from Detroit. I just stumbled on this site while looking for measurements of foam-filled waveguides. I've been involved with the original Econowave thread on Audio Karma since 2008 and was the Speakers forum mod on the site for a while. I've built 4 or 5 pairs of E-wave speakers. 3 of them are based on the common Large Advent vintage speaker. 2 years ago I wrote a feature article on Econowaves for Make Magazine, an O'Reilly publication. It's online as well as in print now.
    I've used exclusively the Selenium D220Ti and D210Ti drivers although I've owned and tried the DE250 and DE10. The Seleniums are regularly under $80US/pair here which makes them too cheap to pass up. I find that the foam filling makes a big difference in the top end fizziness of the Ti drivers.

  10. I'd recommend that you cite the source for the photos used in this article. Those were taken by Evan "Zilch" Flavell in his workshop Zilchlab. The speaker under development in the photos uses a 10" X 14" waveguide that we sourced from QSC and a kit trap cabinet from Parts Express that I discovered. Zilch passed away a few months ago and will be missed.

  11. The Selenium D220Ti's are not bad at all, though they have a very etched, detailed sound which some people may or may not like. I imagine they would sound excellent with a SET amp. I own the DE-250 as well, they are both good drivers for their price range.


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