If you have a dip in the bass, it can give you the impression of everything seeming OK, yet at the same time you know something is missing. It can be frustrating.
It may feel like you need some more slam, or maybe some warmth depending on where the dip is.
Don't confuse this with the need for more bass. This is normally what it feels like needs to be done, but bass only sounds right with the right balance of harmonics. A response dip will screw you out of a good bass experience.... and turning the bass up won't fix a dip.
It may feel like you need some more slam, or maybe some warmth depending on where the dip is.
Don't confuse this with the need for more bass. This is normally what it feels like needs to be done, but bass only sounds right with the right balance of harmonics. A response dip will screw you out of a good bass experience.... and turning the bass up won't fix a dip.
I once modeled a tapped "horn" in AkAbak as a straight line (no bends) then again with multiple folds. The folds made no significant difference to the response in the passband that tapped horns are usually designed for. There are tapped horn projects described here in diyaudio that have up to a dozen bends, but still measure very close to their predicted response.
A volume expansion in a pipe (horn) such as a bend without a reflector creates a low pass filter, but in a typical size pipe (horn) it's area/length is only a tiny fraction of the size required to reflect the long WLs of its typical pass-band.
Anyway, you still haven't provided any more design, etc., details, so before moving on I'll just mention that a TL will have a deep notch (suck-out) in its response at its acoustic 3rd harmonic if not heavily stuffed (damped), so ignoring any terminus end correction and room boundary effects, this will approximately be at 4x its axial length, so if the TL is a 1/4 WL of 25 Hz, then the notch will be at approximately 100 Hz.
GM
OK, then the notch is high enough that the 100 Hz XO should knock down its impact on the overall system response quite a bit. Regardless, ceiling insulation is fine, just remove any vapor barrier backing, then stuff the entire first section where the drivers are with a ~1.5 lbs/ft^3 stuffing density. If too much of its bass response disappears, then obviously remove some it. If you feel it needs more though, better to add it from the open end since at some point stuffing gets dense enough to start reducing the pipe's effective volume. Use a grill made from pet resistant door/window screen to contain it/protect if from little hands and/or pets if applicable.
GM
GM
Hold the phone! You shouldn't be able to get to the internal sections. Are you saying this thing isn't sealed up tighter than a drum? If so, then more than likely you have an air leak causing your problem, though once plugged, the other issues are still there, so at least a minimal amount of damping in the first section is required to smooth out its HF response and some fine tuning can be done in the last section if need be.
GM
GM
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