This is an interesting and simple to build project. We sort of fell into this one by accident. We were testing our new CW1228 woofers in a Heresy 1 box. This new woofer was built to be a replacement for the woofers in the Heresy and Heresy II. In those, the woofer needs to go up to 700hz and from that point the midrange comes in to handle the range up to 6000hz and then the tweeter takes over.
Our testing was to verify that the woofer could make it up to 700hz making it a good replacement for the K-22 or K-24 woofers in the Heresy 1 and 2 speakers.
Well, It easily does 700hz in those boxes, and just keeps right on going higher. That started me thinking. All you have to do is make it up to about 1200hz or so, and then you can get a pretty inexpensive driver to take over there and go on all the way to near 20khz.
Since I already had a couple of empty old Heresy cabinets, I started looking at horns and drivers that could make those cabinets into 2-ways using the new CW1228 woofers. Pretty soon, I found the Selenium D220Ti drivers and the Selenium HM25-25 horns. I bought a pair of each and started testing.
Preliminary tests looked good, so I cut out a hole where the old tweeter and midrange horns were in the old Heresy cabinets large enough to put the Selenium horn in. No attempt was made to make these pretty, they are just test mules to work out how the parts work in this rig.
Crites CS-1 Prototypes
The crossover was the next thing to work on. We went through a few designs and settled on a 4th order for the woofer and a 2nd order for the HF driver.
Here is the curve we got on the speaker after tweaking in the crossover design.
This may be small and a bit hard to read, but we got a good response from about 55hz to about 19.3khz at about plus or minus 3db.
Like the Heresy, these will not produce low bass. The cabinet is just too small for that. If you want low bass, you have to go to a large cabinet and I suggest our Cornscala project for that. But these do sound really good and are a nice small package.
So, if you want to build these, an old pair of Heresy cabinets would be one place to start, or, this is a very simple cabinet. Building these would probably be as easy as a speaker building project could be.
The cabinet is a sealed box with these internal measurements. Internal is what matters because we have to get the right volume for the woofer to work right. Remember to add the thickness of your material to these measurements to get the exterior measurements.
You can vary these measurements a bit if you want as long as you maintain the 1.93 cu. ft internal volume. Of course, you can't vary them much because, as you can see from the picture, the horn and woofer take up almost all the front. And you have to consider how deep the cabinet has to be to make sure the horn and driver have room to fit between the front motorboard and the back of the cabinet.
Parts you would need are:
Pair of CW1228 woofers $170.00
Pair of Selenium D220Ti Drivers $80.00
Pair of Selenium HM25-25 Horns $40.00
Pair of CS1 crossovers $200.00
We can ship all that to most places in the US (lower 48 states) for $40.00 by UPS. Customers in Alaska, Hawaii or Puerto Rico or other countries, please contact us for a shipping quote.
All these parts are in stock except the crossovers which we would build when you order. Usually we can ship those within a couple of days.
UPDATE July 11, 2010
Thought I would show a few pictures from a recently completed set of 3 CS-1s. These were made by John in Australia. I think he did a great job. I always like to see the innovations that different builders use in these projects.
