[OBF]

Al, Dan (if you're still checking this circle), or anyone:  I was asking some questions on the DIYCable circle about the suitability of the Extremis driver for sub bass applications and it was mentioned that you're using them extensively.  My original post with details is below, but briefly I'm looking for a driver (with cost in mind) that can handle both deep bass (would be eq'd) and also cross much higher than most subs (250hz+) for use in a TacT system.

http://www.audiocircle.com/index.php?topic=25142

Because of the high cross and reasonable price I thought of the 6.8.  However, I'm not sure how much sucess I'd have with 1 driver per side and I notice RAW is mostly using them in pairs.  The TacT will boost the output down in the 20s, but of course that doesn't do much good if it blows up the drivers.  I don't really need flat 20hz bass as I'm currently using Ellis 1801 2-ways with SEAS midwoofers, so I don't have the bottom octave now.  I'm mostly looking for more impact at 30hz plus some extra extension (and these will be corner loaded).  Going with 2 per side turns a cheaper solution into a less cheap solution, but maybe it's necessary.  Thoughts?

Do you think the 10" XBL driver could handle that high of a crossover?  The TacT/Lyngdorf subs use 10" drivers in that application, but they say they are "special" drivers and cost a fortune.

Al, also wondering if you still have the clearance cabs that are on your website?  The posts on the circle are a few months old.  I'm thinking that could be a cheaper way to try 1 Extremis/side by plugging up the ribbon hole.  If that didn't work, would the internal volume be appropriate if I removed the baffle and made a new one for 2 woofers?  I'm also not sure if the bracing would even allow another woofer.

Thanks for any advice,
Mark

[kfr01]

Mark:

Try downloading WinISD Pro.  http://www.linearteam.dk/default.aspx?pageid=winisd

(Free speaker design software)

Enter the T/S parameters of the Extremis, and you'll get a rough estimate of what you'll be able to do with the Extremis driver (and what size enclosure you'll need).  

It even has filter / eq similators and resulting cone excursion estimates.  

Depending on your room I'd estimate that you wouldn't quite want to EQ a single Extremis per side flat to 20hz.  Again, this depends on your room. If you have a lot of room gain down low, you might be fine.  If you don't have a lot of room gain down low, you may find a single pair running out of excursion room if heavily EQ'd down at 20hz and playing at HT volume levels. If you go Extremis, I think I'd probably at least double up.  More likely, I'd probably make a nice even stack of four, if I were you.  That'd provide you with some nice excursion headroom and let you wire back to 8 ohms.  

Karl

[RAW]

As Dan has said on Kevins forum using a pair would be best suited for your use.
We have a few customers who have built small subs with Extremis a single and double extremis sub.
Matched with a Hypex Amp.

We like the single Extremis in the HT6 and HT3 does them both a lot of justice for low end  
Putting 2 in each HT8 was because we wanted a lot more low end out of the HT8 and believe me 4 of the Extremis do just that

If you can go to 2 for the sub you will have more power handling as well as strong over all impact that 2, do not get me wrong 1 is still a lot.But for a sub I would go to a pair and have a tuning of 30hz no lower.
Why well say power handling you will have that sub volume seeing a lot more power than you mains.

[kfr01]

All:

Correct me if I'm wrong, but won't a design using the Extremis drivers in a small sealed enclosure be better suited to Heavy EQing in the bass region? --- Especially below 30hz.

[RAW]

Yes.
That is why I said to compaire in our HT# and HT6 both of which are ported.

Sealed will need need eq.
But really for the price start looking at a 10" or 12" And be done with a sub.
Or a Mult and put a smaile on your face from ear to ear

As for the clearance cabinets yes we still have a few left but not many.
People are purchasing them 4-6 at a time.

To replace the front baffel is a lot of work and you still have the port hole to deal with in the back if you wanted to seal them.

[OBF]

Thanks for all the advice.

But really for the price start looking at a 10" or 12" And be done with a sub.

That's why I was asking if the 10" could handle a 250hz crossover.  I assume not, but you never know.  The advantage of a high crossover is because the TacT can generate a seperate correction for each speaker and each sub, so the higher you go the more room/bass problems can be fixed without affecting the mids and highs.  Is the SX-10 on your site an actual product or a prototype?  I didn't see any pricing like the SX-12.

kfr01, if you have a spare minute could you pm me sometime about that software?

[kfr01]

OBF:

Adire will have to answer the question re the subs.  At least their older tumult had fairly decent response to 250.  

Most subs have some breakup nodes (irregular frequency response) higher than 200hz.  If a sub has some frequency response irregularities above 200hz, you normally cross over at least an octave lower and use a steepish (24db+) slope so that the irregularity is pretty attenuated.  With the tact you can probably use -very- steep slopes (48db+), so you can probably push most subs higher than you normally could.  Adire usually pays pretty close attention to bandwidth versatility with its drivers.  My guess is that with a steep crossover you'll be fine.

OBF:  Please pm me any questions you have about that software.  I'll be happy to try to answer them.  I find the big hurdle with that software is just entering the driver parameters correctly.