ML-TQWT port direction : down/forward?

[Jim McPherson]

What if any difference does port direction make when building an ML-TQWT? I'm finishing up a new design and was ready to cut frount facing ports when I came across the "solo" :http://diyaudio.8m.com/Solo/solo.html where the port fires downward. Would the down firing port do anything to quell the ripples in the midrange inherent to TQWT's?

-Jim

 

[Jim McPherson]

Any ideas?

-Jim

 

[Timn8ter]

I'm not aware of port direction making a significant difference. I'm curious about why you feel that mid-range ripples are inherent. Most of the TLs I've heard have the best mids around. The mid-range is usually controlled by driver placement and stuffing.

 

[GM]

No. Assuming the vent is in the lower 5th of the cab, placement is for looks/convenience. Bottom exit is nice if they sit on carpet as it attenuates port noise somewhat, allowing a smaller/shorter vent. If on a hard surface, the distance can be adjusted to further mass load the vent, either allowing for a shorter than predicted one or 'pumping up' the bottom end some. Ditto rear firing.

GM

 

[Jim McPherson]

The "inherent" ripples idea comes from the modeling (Martins) / RTA's I've seen compared to comparable to straight up bass reflex enclosures. Sure stuffing helps, but it seems like "cheating". I was hoping to get by with as little stuffing as possible.

Thanks for the suggestions. I think I'll try a downward firing port.

-Jim