More Model 19 questions

[les winter]

My 19's are clones, with 416Z woofers and 9028A horn drivers. Presently they are tri-amped with the horn/woofer x-over at 24 db/oct 1200 hz. Sounds really nice.

But I have a curiosity as to what the originals sounded like. I'd like to try the passive crossovers. So I have an 8ohm horn driver and a 16-ohm low frequency speaker.

Can I build the original x/o and hang a 16 ohm resistor across the woofers? Swap the woofers for 8 ohm versions? Build the Zilch version and adjust for the higher woofer impedance?

Any input appreciated.

thanks
Les

[ZilchLab]

Can I build the original x/o and hang a 16 ohm resistor across the woofers? Swap the woofers for 8 ohm versions? Build the Zilch version and adjust for the higher woofer impedance?

Unless you have HF compensation in your active setup, you're not hearing M19 performance.

Build Z19s, doubling the L and halving the C in the lowpass for 16 Ohm woofers. If the HF ends up out of the adjustable range (too "hot"), lower the bridge cap from 6uF to 4 uF to increase the overall HF attenuation....

[les winter]

Thank you Zilch. I should have included that I am using the compensation from the original 19's for the horns. Has anyone listened to both the Z19's and the originals and commented? I searched around but didn't see anything posted.

thanks again.
Les

[ZilchLab]

One or two builders have compared them. I suspect a large element in their preference for Z19s is that the components are all new, and to spec. Nobody's done the Solen vs. Dayton vs. whatever thing yet.

The alternative source of HF drive in Z19 results in a wider range of adjustability and reduced interdependence of the controls, i.e., they're easier to get "right." They are also biampable, for those who might desire even further SPL freedom, or prefer to run the HF on toobes....

[les winter]

Tubes is me.

Thanks for your input.

I have the big inductors on hand.

I'll do the Z19.

regards
Les

[amandarae]

What is the "Zilch" version of that XO? Where can I see the schematic for it?

Pardon me, I am pretty new to this forum.

thanks,

Abe

[ZilchLab]

I'll do the Z19.

Report your findings, please.

[We'll want pics, too. ]

What is the "Zilch" version of that XO? Where can I see the schematic for it?

http://www.hostboard.com/forums/alte...ml#post1845497

Scroll back from there to see measurements of current GPA 902-8a driving 811, 511, and MR931 using it....

[amandarae]

Thank you very much Zilch!!

Two other questions if you do not mind, first, can I use it for a 416/802D combo? Second, what is the effect with regards to sensitivity? In other words, with your XO in use, what will be the sensitivity rating of the speakers?

Thanks very much in advance!

Abe

[les winter]

Zilch: here is a pic of the completed 19 w/o the ducts and without the foam on the horn.

[ZilchLab]

Two other questions if you do not mind, first, can I use it for a 416/802D combo? Second, what is the effect with regards to sensitivity? In other words, with your XO in use, what will be the sensitivity rating of the speakers?

416 is a Model 19 woofer.

The system sensitivity is a function of the woofer sensitivity, so long as the HF compression driver has sufficient efficiency to balance with it.

802Ds do not have tangerine phase plugs, and to the extent that it relies upon them, you'll not be able to achieve extended high-frequency response using Model 19 HF compensation topology. If that's what you're after, you'll need 802-8G or 902 class compression drivers.

Zilch: here is a pic of the completed 19 w/o the ducts and without the foam on the horn.

Mighty beautiful work, I must say....