RST28F and DC130A Foamcore Homage to LS3/5A

Founder of XSA-Labs
Joined 2012
Paid Member
Our ears don’t hear dips easily - they are not annoying like a peak at a certain frequency. But I would never try to design one in on purpose. However, a dip is sometimes helpful to reduce a natural resonance peak associated with the human ear when using IEMs. The length of the ear canal with IEM has a few resonance peaks at about 2.5kHz and 7kHz, anatomy dependent. Siegfried Linkwitz made a passive EQ circuit for his own IEMs that had a transfer function that looked like this:
etymot-eq1a.gif


Maybe the BBC dip at 3.5kHz is for a similar reason?
 
Founder of XSA-Labs
Joined 2012
Paid Member
Nice! Thanks for trying it out. That was quick work by you. :)

Any photos? Would it be made of foamcore?

870175d1598224698-rst28f-dc130a-foamcore-homage-ls3-5a-ls3-5a-foamcore-dc120a-rst28f-build-photo-jpg


For those of you browsing on your iPhones. I just found out that you can download the zip file sound clips and it will extract it. Click on the file and it plays music right away. The phones have gotten better at this lately.

Sound clips here:
RST28F and DC130A Foamcore Homage to LS3/5A
 
Last edited:
HI XRK,

Another interesting project. Looks like there won't be any boring stuff from you.

Just out of curiosity, I would like to understand your design choices.

1) You used Noico as dampening material. Is it better than just the run of the mill bitumen pads.

2) You used both the egg crate foam and the melamine foam in your acoustic dampening. Is there a reason why you use both? I know you are a big proponent of the melamine foam, but why do you still need the egg crate stuff?

Oon
 
I apologize for messing things up. I am unsure how to get the picture from the box where you collect it to the box where you show it. I just dragged and dropped. I also don't know how to rotate my photo. The drivers are the RST28 and DC130 in the first picture. The 2nd is a 12" B&C driver with a BMS horn driver and a Pyle horn.
ps: The 12" is not flush mounted.
 
Last edited: