Playing with /dev/speaker

I've started to compile FreeNSD on FreeBSD AMD64 (my QEMU is still compiling the software used on FreeNAS).
And I found, for the moment, two problems:

===> aaccli depends on executable: aaccli - not found
===> aaccli-1.0 you need the 32-bit libraries installed under /usr/lib32 to use this port..
===> beep depends on executable: beep - not found
===> beep-1.0 is only for i386, and you are running amd64..

And, in my quest for a solution to solve the FreeBSD port of"beep", I found that this tools can be removed without problem ;-)

Here is example of using /dev/speaker device (you need to do a "kldload speaker.ko" before):
echo geL2eL4fdL2dL4cdefggg > /dev/speaker

echo
"l12<eaebegae>c<e>d<eb>c<eaebegae>c<e>d<eb>c<ebe"
> /dev/speaker
echo "T250L8CE-GE-C" > /dev/speaker


Then I can remove the 'beep' tools now, but I must found the equivalence to this old command:
beep -p 500 75
beep -p 1000 75
beep -p 2000 75
beep -p 3000 75

My actual equivalence is:
echo "O1L15aO2L15bO3L15cO4L15d" > /dev/speaker

Is someone can propose a better equivalence ?

Games open ;-)