2641's Down firing port?

alethos · « **on:** 25 Nov 2005, 11:49 pm »

Planning on building a set of the 2641's, but asthetically i'm not too pleased with the monsterous port on the bottom. My idea is to build the cabinets with legs and attach a bottom (same size as cabinet or larger, haven't decided yet), how long do the legs need to be (distance from port to bottom of the legs) so I don't mess anything up accoustically? Is this even possible? Thanks in advance for the help.

Kevin Haskins · « **Reply #1 on:** 26 Nov 2005, 05:09 pm »

Probably not a good idea. You can port it out the rear without a problem. Is that a problem? Porting it out the bottom puts the mouth of the port in close proximity to the floor increasing the length of the port. What that will do for port tuning would have to be measured.

wildfire99 · « **Reply #2 on:** 27 Nov 2005, 05:26 am »

If it was a big deal to me, I'd just put a grill on it. Assuming you don't want to cover up the drivers, you can always do a half grill. Maybe something with a nice, concave top (like a U), accentuating the roundness of the lower extremis.

Or, maybe a sealed box with no port at all, if you don't mind the loss of bass?

alethos · « **Reply #3 on:** 28 Nov 2005, 04:34 am »

Thanks for the suggestions. I don't want to go sealed as it's going to be a while before I can scrape together the cash for a dedicated sub. I hadn't thought of the grill option, I'll have to give that some consideration. As for porting it out the back, I don't know exactly how I'm going to place the speakers. If I were to port it out the back, wouldn't having them placed too close to the wall do the same thing as porting it out the bottom (i.e. lengthen the port or something akin)? If so, then how far away from the wall would be the minimum placement so nothing gets messed up acoustically?

kfr01 · « **Reply #4 on:** 28 Nov 2005, 04:40 am »

Alethos:

I just embedded small grill magnets into my front baffle... that way if I ever decide to hide / protect the drivers + port, I can.

wildfire99 · « **Reply #5 on:** 30 Nov 2005, 01:49 am »

Placing the speaker near a wall will alter the bass response no matter where the port is at (or even if it has a port). That said, I've had speakers right next to the wall, rear-ported units just a couple inches from the wall, and even rear-ported units smack up against a support column.

With the exception of the last case (they were placed for simple ambiance in a temporary setup), I can't say that the general signature or "sound" of the units was noticeably changed. They sounded good no matter what. I'm sure they would sound even better when placed properly, which is something that has to take into account the entire room as well as the speakers themselves, not just wall proximity or porting.

While I'm not a guru on it, I'd feel comfy with a foot between the back wall and the port, and somewhat more than that between the speakers and the side walls. But in my experience it's not the end of the world even if they aren't.

Kevin Haskins · « **Reply #6 on:** 30 Nov 2005, 01:28 pm »

Quote from: wildfire99

Placing the speaker near a wall will alter the bass response no matter where the port is at (or even if it has a port). That said, I've had speakers right next to the wall, rear-ported units just a couple inches from the wall, and even rear-ported units smack up against a support column.

With the exception of the last case (they were placed for simple ambiance in a temporary setup), I can't say that the general signature or "sound" of the units was noticeably changed. They sounded good no matter what. I' ...

A lot depends on where the port is tuned and what kind of program material you are playing. If you play a sine wave near port tuning and move it back and forth from the boundry the change is noticable. For the most part, music isn't like that though so you can get away with near boundry conditions without too much concern. Pull them out if you are going to do some critical listening.

The room plays such an important roll at low frequencies there is no simple answer. You have to play with placement in your room until you find what works best for each individual situation. The speaker set-up guidelines are great starting points but you have to be willing to play around with placement to optimize. That doesn't mean they cannot sound good with non-optimal placement and most of us often have our speakers tucked away for spouse approval factor and just normal use of a living space.

alethos · « **Reply #7 on:** 30 Nov 2005, 10:47 pm »

Very good kind sirs. Thanks for the input.