Jordan Eikona 2

[perceval]

Thanks. sorry for the stupid question. My An 10's are .23 so the Jordans are actually a better choice for OB.

Qts of a full range driver is not so relevant in an OB design if you are going to support it with a woofer for bass duty.

 

[planet10]

All depends where you are crossing over and how big your baffle is. I would opine that the Eikonas probably sound better (i’ve not heard them yet).

dave

 

[scottjoplin]

Depending on how low you want it to go and how you are implementing it it has high excursion, not that I'm a big fan of that though, I crossover at 130 Hz and just about manage without any EQ

 

[mkane77g]

These will get a trial run in NP SLOB. Mini DSP HD ordered. Crossed @ 80Hz. Mr. Pass says to skip hertz from 80 and go directly to 160Hz.???????????m I'll use the AN's upstairs or out in the garage. I have 1808 coming also. Speaker rabbit hole!!

 

[perceval]

Well, I'm sorry, but no amount of Qts will let a 4" driver play down to 80Hz in OB. Even 160 is pushing it.

I'm a big advocate that if you have a nice big woofer to help, why not really let it help the often smaller full range driver so it doesn't have to struggle playing down low, and frees it to cleanly play the higher frequencies.

I will often XO in the 250 to 400 range depending on the curves used.

 

[mkane77g]

Can't x over that high in this SLOB. I'm going to set this up so that the Jordan come on after 160Hz. And if that doesn't work I'll make an H frame or a Z frame for the woofers.

 

[scottjoplin]

Baffle size and shape not driver size is the main deciding factor. Also bare in mind that the dipole cancellation doesn't happen in the real world quite so simply, you need to take into account distance from front wall and reflections. Crossing over at 160 Hz is perfectly doable

 

[mkane77g]

I thought baffle size wasn't a huge factor with the FR driver.

 

[scottjoplin]

It will determine (to some degree) where the dipole cancellation begins, exactly the same as it does with a bass driver

 

[Scottmoose]

Well, I'm sorry, but no amount of Qts will let a 4" driver play down to 80Hz in OB.

Actually, assuming the driver has a sufficiently low Fs & reasonable Qt, there's no reason why it can't play down to 80Hz on an open baffle. It just won't do it very loudly.

 

[perceval]

Actually, assuming the driver has a sufficiently low Fs & reasonable Qt, there's no reason why it can't play down to 80Hz on an open baffle. It just won't do it very loudly.

Well, that was kinda my point...
But you phrased it much better than me, and more succinctly. Thanks!

 

[chrisb]

Scott Joplin is doing just that.

dave

scott - did you ever post any photos of that?

 

[GM]

Well, I'm sorry, but no amount of Qts will let a 4" driver play down to 80Hz in OB. Even 160 is pushing it.

I'm a big advocate that if you have a nice big woofer to help.......

I will often XO in the 250 to 400 range depending on the curves used.

Not technically true, but the baffle will be quite wide and power handling would be limited to as little as a fraction of a watt, so realistically not an option.

Me too; a good 'rule-of-thumb' is to XO at the driver's effective [Qts'] mass corner [fhm], which for this driver would be in the ~123-225 Hz range depending on amount of series resistance based on published specs with of course the highest power handling, smallest baffle being with minimal series resistance [~0.5 ohm speaker wiring only].

fhm = 2*Fs/Qts'

Qts' = Qts + any added series resistance: mh-audio.nl - Home

GM

 

[scottjoplin]

scott - did you ever post any photos of that?

Arranged a bit differently now, this is an old photo, the Jordan's are just in the VTL cabinet with the back removed

 

[planet10]

As an example related to the latest bit of discussion, we used a 6.5” custom (Korean) alnico driver aimed at OB in a 17’ wide OB at one diyFEST (outside in the garage apron) and bass was considered tremendous.

dave

 

[chrisb]

it does bear mentioning that the cumulative baffle size of 17 ft would be rather unwieldy in a most world rooms - even your own big space?

 

[planet10]

The temporary 17’ baffle made it impossible to get into the garage, blocking the entire open width of the apron.

dave

 

[scottjoplin]

That would almost be an IB, there would be no reflections so not a usual dipole set up. It's similar to my first experiments with OB. I would expect pin point imaging and not the usual depth and spaciousness that you'd get with a dipole in a room?

 

[planet10]

To be an IB it would also need to reach up. As shown it is only 1.2m tall.

dave

 

[scottjoplin]

Yes, but all the other directions are covered, it wouldn't be far off