[Paul Spencer]
Q: Is it possible to design a fully optimised bass horn this quick?
A: Probably not!
This is a quick start guide. If you have never used horn response before,
try this and you will have a result in 2 minutes. It might be bigger than
you'd like, you may not have made the best driver choice, and there will
most likely be a lot of room for improvement, but you will have a start.
[Download Hornresp if you don't have it already]
1. ANG: Enter
0.5 This is for corner loading. (It will appear as 0.5 x Pi)
Enter
2 for outdoor use or
1 if it will sit on the ground against one wall.
2. Below the horizontal line, enter driver parameters.
Use these as an example:
Peerless XLS (car version)
SD: 352
CMS: 0.00014 (this will appear as 1.40E-04)
MMD: 117
RE: 1.8
BL: 11
RMS: 1.8
LE: 1.5
ES: 2 (2V into 4 ohms = 1w)
3. Enter 0 for all values below this.
4. From the Tools menu, select "Hypex Designer."
Select a bandwidth of 40 - 80 Hz.
This is a good range for a folded bass horn.
You will notice it has chosen some of the values:
S1: 232
S2: 7356
HYP: 287
F12: 40
S1 should not be less than half SD. It's fine in this case.
S2 mouth area. This would be a horn mouth that is 0.4 x 1.8m.
HYP length - the horn is 2.87m long.
You will also note VRC (volume rear chamber) is 21L.
A front throat chamber has been added, reflected in VTC and
in the schematic diagram.
Looking at the result
Around 107db efficiency is achieved.
Response is reasonably flat within the intended bandwidth.
120db could easily be achieved.
Looking at excursion chart, notice that excursion jumps up around F12
until it becomes fairly flat. This is controlled by VRC. Put in a lower
VRC and excursion will reduce, and the rolloff and response will also.
It's at this point you may want to attempt to compromise the horn
to get it smaller, as well as try other drivers. The main parameters to
alter are:
Also try larger values of input power (double click on ES)
For more information on tweaking the design, refer
