I also agree. It does seem pointless and counter productive.
I would like to see anyone else out there post data that shows better performance.
Looking on the bright side, everyone is using your data as the reference.
Thank you.
Elias, you know that gating the impuls response will remove reflections from the calculated frequency reponse when measured with the swept sine technique. That's what Earl does. Did you do that too?
P.S. Earl's data is 1/10 smoothed. I highly doubt that your 2-way box will still look good with that kind of resolution.
Just quoting old stuff is playing "gotcha", in a very childish fashion. It doesn't advance the thread. If you don't have a technical point to make that you can state in your own words, then please don't bother. A ******* match just leaves people... pissed off.
I thought I throw this sim data up to see what points of views anyone has.
Attachments
What kind of point of view could anyone have with so little info? Sound power of a lawnmower in the rain?
To answer your quoted question; no, compression drivers do not produce constant power response, they can't. Above what has been called the "mass break point" (where the mass reactance equals the damping), the power response has to fall. IF compression drivers DID produce constant power THEN an OS waveguide would be flat. But that is not the case.
To answer your quoted question; no, compression drivers do not produce constant power response, they can't. Above what has been called the "mass break point" (where the mass reactance equals the damping), the power response has to fall. IF compression drivers DID produce constant power THEN an OS waveguide would be flat. But that is not the case.
Last edited:
That is basically a sim of around 39mm diameter concaved dome diapragm operating with a 26mm diameter throat coupled with an OS wave guide. Since the polar data looks really nothing like CD should with the high frequencies rising, I did not post them. It was the fact the there was a flat power response that I found interesting. The driver is not a realy driver, just taking the parameters of a 1" driver and changing the diaphragm diameter.
In the process of trying to get more accurate sim results, I thought I'd post the following to show how close one can get.
An externally hosted image should be here but it was not working when we last tested it.
Member
Joined 2003
I've mentioned this before.. Thermoformed, probably with a thin HDPE. Let the customer "back-fill" the waveguide (..which they were going to do anyway unless it was turned wood or an expanded foam).
Material cost is low (less than 10 US per unit), and after a bit of practice with temp control the labor is moron-simple. (..you can also stack it to keep shipping costs low.)
I would think that pricing is not really taking into account the mold costs and setup chargers you would incur. I would suspect you would need to make many 100's if not 1000's to get the cost per unit that low.
For example, i contacted a company capable of thermoforming uploaded designs at what they said was the best pricing around. For less than 50 I had an initial 200 dollar setup fee for items in the size I wanted. What I had designed was a record mat made of a plastic material with a dish toward the center, I figured if I could get them cheap enough, it might be something to sell on ebay, and get me a nice record mat that did what I wanted. Cost per unit, on top of that 200 dollars, was 25 dollars per unit. My total cost, after shipping, was around 35 dollars per item. This was for basically a 4mm disc, and the price was still only so low because the form was so simple for them to make.
For example, i contacted a company capable of thermoforming uploaded designs at what they said was the best pricing around. For less than 50 I had an initial 200 dollar setup fee for items in the size I wanted. What I had designed was a record mat made of a plastic material with a dish toward the center, I figured if I could get them cheap enough, it might be something to sell on ebay, and get me a nice record mat that did what I wanted. Cost per unit, on top of that 200 dollars, was 25 dollars per unit. My total cost, after shipping, was around 35 dollars per item. This was for basically a 4mm disc, and the price was still only so low because the form was so simple for them to make.