Aperiodic?

[jmchrislip]

I was looking at a pair of Dynaco A25 loudspeakers. They look like something between an acoustic suspension and a ported loudspeaker. They are described as an "Aperiodic" loudspeaker system. Can anyone elaborate on this type of system?

 

[elitopus]

Here is a thread that explains it

http://audiokarma.org/forums/index.php?threads/anyone-understand-aperiodic-vents.196358/

 

[jmchrislip]

Thanks elitopus.

 

[elitopus]

Thanks elitopus.

Hey no problem. I was going to try to explain it but it was easier to copy and paste

 

[nexus]

a very good method of bass loading.

..but using it for subwoofer loading is tricky though ACI had success doing just that.

 

[keilau]

I was looking at a pair of Dynaco A25 loudspeakers. They look like something between an acoustic suspension and a ported loudspeaker. They are described as an "Aperiodic" loudspeaker system. Can anyone elaborate on this type of system?

There is a pretty recent thread title "Speakers that have an "Aperiodic" design". Go to the second page for some detailed description of aperiodic history and basic approaches.

http://audiokarma.org/forums/index....n-aperiodic-design.593503/page-2#post-8021033

In essence, the aperiodic bass loading is a compromised design to get non-resonant bass at moderate enclosure size. The Dynaco A25/35/50 series are one the most successful commercial implementation of the Aperiodic design.

The majority of today's loudspeaker are in a bass reflex enclosure which can go fairly deep with a smallish box and has good efficiency. But the twin impedance peaks in such an enclosure is impossible to completely damped out. It impairs the transient response of the bass and give it a "ringing" type character. The bass sounds "lossy" or "boomy" to some listeners, but good, deep bass to others.

The aperiodic enclosure gives the kind of tight (rapid transient and decay) bass some listeners consider "more accurate" in a moderate sized box.

It is a personal choice that which type of bass one prefers. But they are very different to listen to.

 

[jmchrislip]

Thanks keilau. I hope to audition a pair someday. I'm very pleased with my Smaller Advents but was curious about the classic A25's.

 

[nexus]

aperiodic subwoofers like ACI and their large speakers were often compared to the smooth bass of well designed transmission line speakers but of course they don't quite have the bass extension.