Vertically Oriented 2x10 Cab - Front Ported?

[Bassman Rich]

On 20/08/2024 at 04:19, Bill Fitzmaurice said:

It does, but it doesn't matter. Low frequency projection is 360 degrees. That means rear ports project as much sound to the front as they do the back. By the same token front ports, and for that matter the cone,  project as much sound to the back as they do the front. Dispersion only narrows to 180 degrees when the baffle width is one wavelength. At 100Hz that's 3.4 meters. At 50Hz it's 6.8 meters.

Thanks Bill. It sounds completely bonkers, but that's what science is for, making sense out of what originally seems madness. I tested out (without knowing this stuff) an 8 x 10 cab at our rehearsal room last night, it seemed louder, or at least as loud, when I was at nearly 70-80 degrees around from the front, rather than directly in front !!

[TimR]

Dispersion frequency is inversely proportional to speaker size. 172000/diameter(mm)

 

So any higher frequencies coming from the ports. Will be constructive/destructive to what's coming out of the speakers. 

 

However, in practical very unlikely to hear any difference unless the ports are at ear level.

[Bassy]

Eden D210XLT are double front ported. Shameless plug...I have 2 for sale on this site.

 

Edited August 25 by Bassy

[Bill Fitzmaurice]

On 21/08/2024 at 07:18, TimR said:

So any higher frequencies coming from the ports. Will be constructive/destructive to what's coming out of the speakers. 

However, in practical very unlikely to hear any difference unless the ports are at ear level.

Higher frequencies seldom come from ports at a significant level. About the only time that happens is when a rear mounted port is in back of a woofer, which would be rare, as a port would have to be very short to fit there. When there isn't a direct line of sight through the port to the cone higher frequencies won't come through the ports at high levels. For that matter low frequencies don't actually come through the ports. This goes to how ports work. The air mass within the port vibrates back and forth, the portion of that slug of air that meets the outside air acts like another speaker cone. Unlike a speaker cone it only vibrates at and near the tuned frequency, so the bandwidth of the frequencies it passes at a high level is quite small, on average no more than an octave.

[Bleat]

Laney Nexus n210.  Front ported, has feet on side to stand it vertically, top mounted handles, lightweight. Can only buy used now.

[JottoSW1]

2 hours ago, Bleat said:

Laney Nexus n210.  Front ported, has feet on side to stand it vertically, top mounted handles, lightweight. Can only buy used now.

Love the Nexus Cabs but don't have any n210s  n115 is a great little 15" cab.