# My little Center Channel project.



## Wildcard26 (May 22, 2007)

Well I just finished this and I am pleased, I should be, coming from a Polk Audio CS 101. I thought hey it can't be worst than that. Did alot of research on design and Xovers. The final design was 20" W x 6" H x 8" D, drivers were Buy Out 5.25" from Parts express and tweeters were the ND20FB-4 from Dayton. Cross over was also done with components from Parts Express (Dayton caps and Jantzen air core inductors). It was designed to have a 51Hz @ 89 db response in a sealed enclosure as this gave a much better model in WINISD and a second order cross over with 5000 Hz and 3500 Hz points. I had an extra terminal pad lying around so it became bi-ampable for no reason. Off axis performance is not too bad as voices still remain distinguishable. The tweeters have been said to be a bit harsh and they are but it's tolerable. Noticed I had to raise my volume a bit more due to the lower sensitivity of the drivers (87 db for the mid-bass, 93 for the tweeters) but it's in better timbre with the mains now. and gives a much fuller sound. So here it is, nothing much but it works for me, better than the CS 101 .

The front:









The back:










In position:










The mains were once black but I changed that. I also redid the top of the sub (left corner, ED 13 K.v2, powered with a BASH 300s finished with a carpet wrap a la Sonosub an gives 20Hz at 110 d according to model in WINISD). Enjoy.


----------



## Sonnie (Apr 11, 2006)

Nice work... I've never seen tweeters side by side like that. Interesting!


----------



## Wildcard26 (May 22, 2007)

Well, I worked a bit of research here in terms of that the tweeter was made to work well in arrays as well. The other factor I was considering was that generally for an MTM off axis placement of the tweeters works better for comb filtering, Consideration was also placed that I wanted to get a wider coverage so it also supposed to resemble 2 MT next to each other. I wanted to get the mid woofers as close to the teeters as possible to almost sound like one driver. So far I can say that it has achieved all that I came up with in researching. I am satisfied to say the least and I know that some may have may have alot to say about it but the most important thing to me is that it sounds just as I like and it makes me feel achieved. Thanks you for your comments on this, I really appreciate your input.


----------



## Kal Rubinson (Aug 3, 2006)

Sonnie said:


> Nice work... I've never seen tweeters side by side like that. Interesting!


You rarely see it because it is not, generally, a good idea.


----------



## Wildcard26 (May 22, 2007)

Educate me Kal. All things aside I still like how my Center Channel performs but I really would like to be educated on things about this. Thanks.


----------



## Kal Rubinson (Aug 3, 2006)

Wildcard26 said:


> Educate me Kal. All things aside I still like how my Center Channel performs but I really would like to be educated on things about this. Thanks.


I have posted information about this here in other threads, in other forums and in my column. So have many others, so I will be very brief. Radiations from drivers producing the same sounds will interact destructively in the same axis. As a result, vertical arrays will have limited and irregular radiation in the vertical plane but better radiation in the horizontal plane. (The only relief from this constraint is if the drivers are closer to each other than 1/2 the wavelength of the relevant frequencies.) That is why the vast majority of decent speakers for any purpose are vertical arrays. Only so-called dedicated center speakers utilize horizontal arrays for esthetic, ergonomic and irrelevant reasons since the laws of physics are unchanged.

Kal


----------



## Wildcard26 (May 22, 2007)

Well I t read this before but I can't say that I was able to completely get this out of the way since how the tweeters are mounted there is exactly frame to frame as they are rear mounted. As in the case of these tweeters what would you have to say about the design?


----------



## Kal Rubinson (Aug 3, 2006)

Wildcard26 said:


> Well I t read this before but I can't say that I was able to completely get this out of the way since how the tweeters are mounted there is exactly frame to frame as they are rear mounted. As in the case of these tweeters what would you have to say about the design?


I would have gone with one tweeter as long as it has adequate power handling for the application. If there was a requirement for two, I'd have stacked them to eliminate the horizontal offset between them and to minimize the horizontal offset between the two mid-woofers. What is your crossover frequency and how far apart are the mid-woofers?

Kal


----------



## Wildcard26 (May 22, 2007)

Well one of those tweeters I thought would not have had enough power handling and less complication with the impedance as I used 2 (1 is 4 Ohms). The crossover points I used were 5000Hz for the mid woofers and 3500 Hz for the tweeters. The mid woofers are 3.5" apart.


----------

