2435?

[Guido]

Any news with the ferrofluid question?
Thanks

[Zilch]

HF alone is windowed, Full range, not.

-6 dB @16.2 kHz, -10 dB @19.7 kHz.

8-Ohm L-Pad used to balance with LF in full range. Should be 6 Ohms, as I recall.

LF filter is N3134, 1 kHz.

I can dial it flat from 300 Hz up within +/- 2 dB. Just sounds a bit bright to me balanced like that, is all.

Impedance, bottom.

[How does it DO that? :dont-know]

[4313B]

To be fair the circuit is designed specifically for the 435Be. The 2435 isn't aquaplased so it won't be quite as smooth. You would have to tweak it abit.

Since I last heard these the 045Be's have been turned off. The 435AL in the 880 Array center channel has been replaced with a 435Be. The 435Be's are running with the circuit posted above (charge coupled of course) actively crossed over at ~ 750 Hz and are 6 dB down at 20 kHz. This is the current pinnacle version of the 12-inch 2-way. The final step is to replace the 435Be's with 476Be's and six of them have just been taken off the shelf for that very purpose. Curves were ran to match pairs but that was proven unnecessary.

For my personal system I've decided to go with the 1500AL's instead of the 1200FE's.

[Zilch]

So, active filter does the highpass; this is the compensation filter?

I.e., don't crank this without rolling off the low end at some desired frequency and slope (between 800 Hz and 1.2 kHz for 2435HPL, perhaps,) to blend with the LF?

[4313B]

So, active filter does the highpass; this is the compensation filter?

Or passive, pick either. Start with an 8 to 10 uF capacitor for passive and change until it looks and sounds right.

[I.e., don't crank this without rolling off the low end at some desired frequency and slope to blend with the LF?]

Well yeah. If you're going to listen to it for any length of time you'll have to come up with some kind of blend with a woofer. If I recall you have active filters on hand.

Just stick it on a 2435 and horn of your choice and measure it with 1 or 2 volts input.

You aren't going to blow it with 1 or 2 V.

[Zilch]

COOL!

Thanks, Giskard!!

[Zilch]

First order passive, 12 uF, Blue.

It wants second order for this combination, looks like, but it's mighty fine listening for right now.

I'll try active tomorrow....

[John W]

Zilch,
Thanks for posting these plots.
I'm having a little problem matching your filter to the schematic, though.
Are both of the smaller caps 1uf? What did you come up with to get to 10.7 ohms?
Any ideas how different the filter would be with 10.5 ohms for the first resistor and 1.5mH on the last inductor?

[Zilch]

Hi, John.

I've been playing 2435HPL on PT-H1010 with this filter for two days, now. Smooth as that single-malt.

It's two 1.0 uF. I originally misread it as 0.6 uF on a printout, so that's 1.0 and 1.5 uF in the pic, i.e., wrong.

For 1.6 mH I used 2.0 mH, 20 ga, and unwound 32 turns.

L2 is 18 ga.

L1 is 20 ga.

Inductors are all Jantzen.

My bias resistors are 2.2M in the pic, as I ran out of 1.5M.

[Or misplaced 'em in the wrong bin, maybe.... ]

[Zilch]

Any ideas how different the filter would be with 10.5 ohms for the first resistor and 1.5mH on the last inductor?

10.5 Ohms will alter the attenuation slightly.

1.5 mH will narrow the notch at 1.8 kHz a bit, and deepen it.

When Giskard posts something to try, we can bank on it being precise.

So, I stick with the program, at least 'til I understand it.

http://audioheritage.org/vbulletin/s...4&postcount=21

[John W]

Thanks Zilch,
I see now that your resistor values are also taking into account the DCR of the inductors, which makes sense.
I agree it is best to just stick with the exact values, all else being equal. Is this filter meant specifically for the h9800?

[Mr. Widget]

...designed specifically for the 435Be. The 2435 isn't aquaplased so it won't be quite as smooth...

Here is a comparison I ran comparing the 435Be with the 2435... they are very similar, but the 435Be does appear to be a bit flatter in response. Aquaplas? That may be it... No ferro fluid? That may be it...


Widget

[Guido]

Zilch, your "Horn of choice" is the H9800?

Could you do some research with an available horn?

OK I'm still thinking about this 2,6 k$ offer but meanwhile....

[Zilch]

Could you do some research with an available horn?

Which horn would you like to see? I'm not doing them all....

It's already been done and it was done in an anechoic chamber to boot. Besides, you really need to do your own research. What Zilch researches is fine for him.

In constructing this compensation filter, I did considerable juggling with stock values to make it happen. I'll post a tentative parts list; perhaps Giskard will have some suggestions as to alternative parts to build with.

In any case, it's not all that expensive to put together and try with an alternative horn of your own choice, but this particular network is optimized for one specific driver/horn combination; others will require adjustments.

My comment was directed at the horns Zilch already had on hand with the intent that he would see the circuit, a light bulb would go on, and he would modify it as desired/required if it was of interest.

The primary illumination thus far being to let the driver do what it was designed to do. Know (or learn) the limits, stay within them, and the result can be quite satisfying.

*****

There's no conspiracy here. The desires and priorities regarding the 1.5" drivers are shared among many forum members....

[4313B]

Which horn would you like to see? I'm not doing them all....

He's already been offered the best available horn and I have the anechoic response to go with it.

Like I said several times already, I really didn't want to get into this for another month or two...