the TL (sub)woofer enclosure

[sergiof]

Once again, I come searching for help... this basically means that I'm thankful of every single idea and suggestion that comes out

Originally, I had the idea of building a 3-way loudspeaker system that would do me the "impossible" 20Hz-20KHz range. This would give me humongous loudspeakers, and even if I knew myself able to sacrifice some space on the living room for those monsters, my girl didn't agree with me much.

Therefore, I went straight ahead to a different approach: a pair of 2 way small bookshelf speakers (on the run, using a sealed enclosure, egg shaped) + one (sub)woofer for the frequencies below 100Hz.

I must confess I'm a huge fan of what's achieved by a backloaded transmission line enclosure, and paying attention to the WAF I ended up thinking on something similar to the "perfectionist audio subwoofer": a huge wooden box that would occupy the space below the flatscreen.

On this idea, I had huge help from pkitt, that made me all the simulations for a TL using Seas L26 woofer, reaching the desired 20Hz. For that I'm extremely grateful!

However, thinking on it as something to endure a longer time, I started thinking: why not using a better (although more expensive) woofer alredy? Is the Seas W26 001 any better? What about the L26ROY subwoofer driver?

Conclusion: The idea is still the same: a mighty woofer on a TL enclosure that would reach the 20Hz with high bass precision, knowing that it would be cut (1st order) at about 100Hz. Help on which woofer to select, and later on the TL drawing is what I'm asking for.

Thank you in advance!

[rhapsodee]

I guess you already know the answer to your questions. You have the simulations for the Seal L26 woofer. Now just do the same with the W26 001 and the L26ROY drivers. Comparing the results - freq response, group delay, impedance curves, impulse response, enclosure volume etc should give you the answer for the best choice.

http://www.audioheuristics.org/measu...fer%20test.htm

I just found this, the L26 woofer seems a solid choice!

[johngalt47]

I'll be interested in your build and the results. I've been considering the L26 also, albeit in a 40L box with Seas' passive radiator.

[sergiof]

Originally Posted by rhapsodee

I guess you already know the answer to your questions. You have the simulations for the Seal L26 woofer. Now just do the same with the W26 001 and the L26ROY drivers. Comparing the results - freq response, group delay, impedance curves, impulse response, enclosure volume etc should give you the answer for the best choice.

10

I just found this, the L26 woofer seems a solid choice!

True... problem is I have no way to simulate the box response. Long time ago, MJKing had his MathCad sheets available for anybody to download and use. Sadly, some people used it as the shouldn't, and the MathCad sheets were removed... If it's true I downloaded those on those days, it's also true my PC died and I lost everything in it...

Anyway, it would be interesting to know which woofer is best suited for a TL box, price and size off the calculations. Who knows, maybe the cheapest (L26RFX/P) will win

[Dr.EM]

Originally Posted by sergiof

Conclusion: The idea is still the same: a mighty woofer on a TL enclosure that would reach the 20Hz with high bass precision, knowing that it would be cut (1st order) at about 100Hz. Help on which woofer to select, and later on the TL drawing is what I'm asking for.

Thank you in advance!

Do you really mean 1st order, 6dB octave? I can't see how that'd work, since the sealed satellites are already rolling off at 12dB acoustically so that sub would need at least second order to mate with them properly. For high SPL the satellites may also use (for instance) 12dB protection filters meaning the sub needs 24dB lowpass. Most subwoofer drivers do not sound pleasant up high anyhow so should be cut off quite sharply, though there are exceptions to this (generally some low Le, lower Xmax drivers).

I built an open end TL subwoofer with two 6" Morel woofers. It certainly had impressive extension, though it was actually rather a large box! Quite a "fast" sound, though perhaps not as much as sealed. If you have one source playing to 20Hz be prepared to use EQ or a lot of experimentation with room placement. The alternative is to use 3-4 subwoofers around the room to achieve a flat response at the listening position.

Good luck with it, it should be an impressive unit! You might be surprised how low it plays in room, my TL wasn't flat to 20Hz on sims but pretty much was in room