What's the deal with the circular disc's.........

[Rick J. B.]

Do the curved edge discs used by many most notably Terry Cain have a purpose besides aesthetics?

I've always thought Terry's looked great, but I've also wondered if they somehow improved performance?

This picture shows Terry's discs well.

An externally hosted image should be here but it was not working when we last tested it.

 

[Klimon]

It's one of the shapes that gives the smoothest baffle step = least ripple, a globe being optimal. There's a page with several forms of baffles + measured/predicted baffle step ripple, I think by Harry Olson. It's online on several sites/forums but I can't seem to find it right now - maybe someone elso could throw in a link.

Simon

 

[Scottmoose]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636&highlight=

They have a few functions. They help improve wavelaunch, and have a slight mass-loading effect for the driver. They also help to scatter reflections from the driver surround.

 

[Rick J. B.]

Thanks Simon, I'll investigate.

I wonder if you used one on the front of a BIB let's say, if any adjustment would be needed to the enclosure to accommodate the fact that you've both changed the drivers relationship with the interior of the cabinet, and have also put it into something of a tunnel?

Rick

 

[Rick J. B.]

http://www.diyaudio.com/forums/showthread.php?s=&threadid=86636&highlight=

They have a few functions. They help improve wavelaunch, and have a slight mass-loading effect for the driver. They also help to scatter reflections from the driver surround.

Thanks Scott, I start reading it yet this morning.

 

[DaveCan]

In that link that Scott provided is a pic of my fe108ez BIB next to the Frugalhorn. I used a round baffle on it and although it's just plain and flat compared to TC's amazing work, the BIB still sounds really good. I needed something anyway because the driver needed more depth to clear the internal divider etc and thats my crappy copy from being inspired by what TC did. Dave

 

[Rick J. B.]

Was it black Dave? If so then yes I saw it, looks good. What do you think of the sound? Bass response?

What were you used to listening to before the Bib's?

Rick

 

[DaveCan]

Yep the black ones. I used to have early 90's 2 way floor standing Missions. The bass of the BIB's is really good and actually quite impressive considering the size of my drivers. Most of all I love the quality and realism of the bass from the BIB enclosure compared to the old Mission's ported cab's. Dave

 

[pikkujöpö]

A different way of doing it : http://www.diyaudio.com/forums/attachment.php?s=&postid=765166&stamp=1131806435

Maybe not as good sound wise or so beautiful as those with separated disc.But was easyer for me to make and I like the different looks...


P.S. I was certainly inspired by Terry Cains work when I these.

 

[ronc]

A supra baffle is akin to a FLH with no gain or collimation effect.
Just think of it as a reverse FLH or wave guide.
There is an IB/OB effect at a given frequency in horns when the loading from the CC and horn path roll off the loading.
All the supra baffle does is pick up the response as the upper horn action rolls off. I tend to look at it as an OB action with no rear wave to deal with.
I believe a combo IB/OB for a higher Qts driver would be a good approach as there would be no rear wave to deal with but there would be a very large enclosure of at least 4 x Vas minimum.
ron