New Project Beta 12LTA Fostex FT17H in a TQWT

[GM]

>So is the PiAlign enclosure design a good match for this driver?

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All things considered, I believe so, or I wouldn't have recommended it.

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>I am looking to get down to 45Hz or so since the Fs of the driver is 45Hz.

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Well, as I noted, the Pi Align is tuned to ~33Hz, so it meets this criteria, though in a sim it looks much less efficient down low than a much bigger cab until you factor in the driver's very low linear excursion (Xmax).

If you can accept whatever audible distortion there is at 2*Xmax and whatever SPL it makes at 10W max , then a ~5ft^3 cab tuned to ~27Hz yields a ~45Hz F3.

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>Is my driver 2/3 of the way down the pipe nuts or is there a chance it might work out?

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Dunno, what does MJK's TL worksheet predict?

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>If I was building this type of speaker, I would use a coaxial set-up and Eminence have several options.

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And yet you didn't. I like the design, I assume it has a some type of rigid baffle underneath. I much prefer the coax over separates also, with the caveat that if the tweeter is used as a supertweeter, then it's OK since the XO is high enough that the audible overlap is outside our acute hearing BW.

GM

[MIKET]

The crossover is at 9000 Hz which would be most likely called a supertweeter. The placement of the fullrange is intended to be at aproximately ear level when seated in a chair.

[GM]

It would depend on the XO slope. Normally, a ST is XO'd at >20kHz/1st or 2nd order. The main thing is that it has rolled off enough by ~5kHz that you can't hear the sound 'walk down' from the tweeter to the wide BW driver, instead sounding like all the sound is coming from one driver.

20.6" up from the floor puts them at ear height?! I take it there's something involved to space them up off the floor.

GM

[Nuuk]

And yet you didn't. I like the design, I assume it has a some type of rigid baffle underneath. I much prefer the coax over separates also, with the caveat that if the tweeter is used as a supertweeter, then it's OK since the XO is high enough that the audible overlap is outside our acute hearing BW.

Sorry GM, I didn't make myself clear enough. If I was building an open baffle with an Eminence driver and a tweeter, I would use a coax type. I didn't use that combo in my case because I already had the Goodmans 201.s.

I presume that you are referring to the polystyrene baffles which were mounted on particle board. They have now been replaced by the panels with the glass wings.

My tweeter crosses over at around 10K.

[MIKET]

Here is an alternate cabinet design to assure the driver is in a more correct position. Parts are all here the 300B amp is complete. Just placed a pair of Mundorf caps on order for the amp. Crossover for Speaker will be assembled with Solen caps 1st. If I am happy with the sound then better caps later.

[GM]

Vents this close to the driver and the bottom of the cab so far away will cause peaking at Fb. Putting them near the bottom will yield a lower Fb for a given vent length and smooth the response out somewhat.

GM

[MIKET]

[GM]

I normally put them a bit closer to the bottom, 1-3" when using tubes, but yours are far enough down to get rid of the peaking at Fb, which is the main thing.

GM