Double 18's stacking

Hi all

Whats the best with scoops? Seen it done both ways but horn coupling makes the most sense

to me it looks like rear loaded horns or ports will play the lower frequencies and woofers the higher end of the spectrum, so drivers should be closer as they will only couple within a shorter distance, while the port or blh will go something like an octave lower and sum coherently even with greater distance inbetween...

bass*en*mass wrote: at freq. below 80-120ish hz, typical for a sub enclosure, it doesnt matter at all imo due to the wavelengths involved..  - i doubt theres much difference in 2x 218s stacked vertically/horizontally ;)

If the cabinet is not coupling to a boundary that is as large as the wavelength, you are going to hear a significant loss in the bass response. Two Double Eighteens is an extremely small setup so, having both cabinets coupling with the ground is going to make a difference. If we were talking 10 - 16 cabinets, the difference would not be noticeable if it were stacked horizontally or vertically.

Best Regards,

bass*en*mass wrote: please show me some sims/measurements of 2x 218s vertically/horizontally (mono) stacked that differ a lot compared to each other in free space/half space.. (at least thats how i understood the OPs question).. hence my honest opinion as per above..

Familiarise yourself with half space & full space loading. Every reputable manufacture that markets their Double Eighteens will spec the height being the shortest and the width being the longest. You want both drivers in a Double Eighteen Reflex Cabinet to couple with the ground unless you are using a lot of Double Eighteens to create your own boundary. All it takes is for you to play one Double Eighteen standing upright (One driver coupling to the floor and the other driver is not coupling to the floor) and the other Double Eighteen laying down (Both drivers coupling to the floor) to hear the difference.

 

Best Regards,  

bass*en*mass wrote: a typical 218 is about 60x120cm, a stack of 2 is equal in both axis.. please elaborate how stacking vertically/horizontally would make any difference.. - that was the original question btw.. :) i am fully aware of what you are saying, its just not the OPs question and topic.. afaik

MARTYNJONHALL is talking about vents versus drivers in which, you are talking about something else. Vents of a Reflex is only prominent when it approaches the tuning frequency. No properly designed Double Eighteen is going to have the vent active within 120 Hz - 80 Hz range as you proposed.

Best Regards,




Edited by Elliot Thompson - 17 October 2017 at 3:20am