Project Small 2-way OB On a Budget - Need advice!

[cowfoot]

Hello diyaudio,

i have been lurking around here for quite some time, but this will be my first post on here.

I have been inspired by all the beautful pictures in the "Ultimate OB gallery" thread and want to build a OB speaker. The thing is that i have limited space and money, so the size and price of the speaker has to be kept down. Im quite new to speaker designing and need some advice and help to reach my goal.

As of now i have done simulations based on the T/S parameters (using BoxSim) utilising the Eminence Delta 12A-2 and the MarkAudio CHR-70.3. The simulation results look like this;

Frequency response:

I think the frequency response looks good, i know the efficiency isn't skyhigh. Will the impendance peak around 500Hz be a problem?

Off-Axis Frequency Response:

I think that the horizontal off-axis response is acceptable. But the vertical response isn't that nice looking. How important is the vertical off-axis responce? Is the dips in reponse around 700Hz a consequence of the crossover topology? Any ideas to how to fill the dips around 700Hz? Will physical time-alignment of the drivers help regarding the vertical off-axis response?

Crossover Design:

Critique?

 

[sreten]

Hi,

Boxsim can't model open baffle loss AFAIK.
The resistors on the bass unit are a very bad idea.
Look at :
http://www.quarter-wave.com/OBs/OB_Design_Part_1.pdf
http://www.quarter-wave.com/OBs/OB_Design_Part_2.pdf

rgds, sreten.

 

[Juhazi]

High fr driver doesn't seem to have any directivity in the plot - There is something basically wrong there. But I believe that this is doable.

 

[mikejennens]

If you're not set on the drivers you mentioned, you might have a look at this: Fast, fun, Inexpensive OB project - Page 46 - diyAudio

Mike