I did not want to hijack Bill's thread. But in thinking about the challenge I decided I wanted to look a different port concepts. So as Chuck pointed out in a design team thread, I am a bit crazy, so I brought every port concept to the challenge. We all knew it was about low bass as a distinguishing factor so I had no misconceptions about what would be competitive (none of these), but still wanted to share the concepts.
First was exposed/ external port
Second was internal port with resonance trap. The new Peerless SLS-85 and Dx20 sound very good. This would have been more competitive with the external port, two SLS-85s and not competing against the speaker above.
Third was Internal and external port, the design used the stand to extend port length. I had a number of people do second takes on these. I admit that I hate the CF120 driver and the ND28 sounds better in everyone else's designs. These are my least favorites
Fourth was no port, or combine the port with the internal volume. This is a 3 liter TL. It got exclude form the competition as the box with the deflectors is large than 3 liters.
So there was a lot of effort to test a bunch of concepts. While I enjoyed it it was not obvious to others what I was doing other than hogging the show.
Comments
I will say your CF120 speaker, from where I was sitting, sounded like you had padded the tweeter down too much, not sure what the FR looks like but your other speakers were all voiced much more consistently than this one and to me it stood out. I was curious about that given that you tuned all 4 speakers, any insight on the FR or anything you found about the XO or design would be intriguing.
Thanks John!
Javad
Regarding the x-o design there was nothing special.
The TL terminus added a bit of mid range bloat so the tweeter level came up a bit.
I split up the Tectonic inductor to be able to notch the baffle step then roll off the top end, all to avoid the 1.7K dip.
The Peerless drivers were just easy
I liked the green Tech 65 speakers the best, they had a very smooth, balanced type sound from top to bottom. I didn't notice the 1.7khz dip at all. Probably because it is a very narrow band type glitch.
Bill
Can you pls post this montage in the InDIYana thread? I as looking for this montage to show my wife and couldn't find it!!! (I found it now!)