S12 OB - Returning to true OB

[gainphile]

This one is to build a true open baffle with its simplicity (no h/w/u -frame etc.) I think there is something about them which other variation simply can't match.

Obviously the low-end output is severely limited .



Still using my set of previous drivers:

Hivi K1
Seas L21 RNXP
Jaycar CW2119

Active XO and 3 amps.

Any comments ?

[Vix]

Very nice!

By the way, what are the crossover points/slopes?

And...can't resist this question: How would you compare it with Pluto's?

[jerome69]

Originally Posted by gainphile

Obviously the low-end output is severely limited .

Add wings

[gainphile]

Originally Posted by Vix

Very nice!

By the way, what are the crossover points/slopes?

And...can't resist this question: How would you compare it with Pluto's?

Thanks. The slopes are 1.5khz and 120hz. All LR4. Some usual SLP and notches for OB.

Yes, Pluto (clone) is a love-hate relationship. They have the best holographic and realistic imaging, yet the sound is coloured by the "box". One immediately notice this when swapping over. I've done numerous swaps before.

So this S12 imaging is close to Pluto, but not there yet. For that I have to use narrower baffle like my "S9". But tonality and "purity" of sound they're miles ahead.

[gainphile]

Originally Posted by jerome69

Add wings

Ah, yes. But then I'm back with the u-frame problems. I can't put my finger on it but using h-frame or (worse U-frame/wings) there is some degree of lost reality and the brain is not easily fooled into the illusion.

My only explanation is, with h/u frames the polar response is not as uniform as simple OB.

This is abit unfortunate as I have wanted to build 4 woofers/channel dipole bass array as in my previous thread.

[craigj]

Originally Posted by gainphile

Any comments ?

Here is an idea, lay your S12 on their sides, raise the Jaycar's crossover to 254hz, combine with the Plutos for for a three way. Do the Pluto clones sound less "coloured"?

From experience, I also agree with your comment "using h-frame or (worse U-frame/wings) there is some degree of lost reality".

As always, have fun.

Cj

[Rudolf]

Originally Posted by gainphile

So this S12 imaging is close to Pluto, but not there yet. For that I have to use narrower baffle like my "S9". But tonality and "purity" of sound they're miles ahead.

To the right on top of the 6.5'' midrange driver in the picture are two Dayton ND20FA-6. They are mounted back to back in a short piece of plumbing tube. Diameter of this 'point source' is 4,5 cm, depth is 3,3 cm.
I have not listened to them yet, still using the double Monacor DT 25N on the left. But the Daytons are almost half that size and should be even better imaging.

[jerome69]

Originally Posted by gainphile

Ah, yes. But then I'm back with the u-frame problems. I can't put my finger on it but using h-frame or (worse U-frame/wings) there is some degree of lost reality and the brain is not easily fooled into the illusion.

My only explanation is, with h/u frames the polar response is not as uniform as simple OB.

This is a bit unfortunate as I have wanted to build 4 woofers/channel dipole bass array as in my previous thread.

Yes I understand and I am agree with you. But you can take the advantage and keep a good polar response.

The wings don't need to be long, 4" (10cm) maximum and it is OK. You could win a little more bass +3dB or more. Perhaps you already have done this ?

Have fun !

[skorpion]

Regarding baffles and No baffles,

Gainphile seems to take a step 'backward' with this new baffle and Rudolf, as always, going front to improve our stereo sensation.

Couldn't the two of you settle this discussion, also provoced by Stig-Erik's thread, of baffles or no baffles, small or more substantial, by measuring various baffle sizes and no baffles at different angles. I suggest 1 m distance and 15, 30 and 45 degree angles, in room measurement. This would be very clarifying for our future developments.

We have the 2.2 diameter guideline, but what we don't really know is if some baffle is better than no baffle.

It would be very interesting if there could be arranged some controlled measurements to illustrate this question.

/Erling

[Telstar]

I think we can just add a pair of subwoofers to compensate the lower two octaves. We already multiamp actively, so what's one way more? Only issue i see is space and WAF.