Son of Zen good choice for driving mid/tweeter?

[Jakob]

Hi,

I'm running an active setup with an ARC VT60 driving the highs (2451J). I would like to use the ARC in another system and was thinking of building or buying a Pass construction to drive the CD's instead.

How much power should I look for? I tend to play rather loud at times but considering I only have a 200W amp for the bass/midbass with driver sensitivity of 95dB/1W/1m and the CD's are about 110dB, a 10 watt amp should suffice, or???

Any thoughts about the Son of Zen construction and sound?

Kind regards,

Jakob

[Robh3606]

2451J

What horn are you using and do you have to do any compensation like CD as an example?? Just remember if you have the 1-2K region padded down say 10Db you don't have to much power available. Just factor it in if you need too.

Rob:)

[yggdrasil]

I have run my mid/hf section with balanced Zen lite, F5 and Zen 9. I enjoyed the sound of them very much.

Keep us posted, the SOZ is a design I have wanted to try, but haven't yet come around to ordering the parts I don't already have.

Johnny

[Jakob]

Hi and thanks for the feedback.

Rob: I use a BSS 366 Omnidrive where all compensation is made. No passive compensation or EQ-ing at all.
I use the wave guide PT 95 something (1.5" throat and 50°x90° dispersion)
Overall, level out from active filter on 2451 is 18dB lower than the rest of the system.
I have a shelf around 2kHz at -5dB, one at 5kHz also -5dB, one at 11kHz +4dB and
at 20kHz -9dB.

Since the horndrivers are approx. 110dB and the bassdrivers 95dB thats a 15dB difference. With a 200W amp for the bassdrivers I can double the output (3dB) almost 8 times. I then end up at (95dB+8x3dB=)119dB. The same calculation with the horndrivers and a 10W amp: 110dB+3x3dB=119dB. Have I calculated wrong or missed anything?

Johnny: I read in Pass' PDF on the SOZ that there is a small DC offset at the terminals. Are the horndrivers gonna be okay with that? I will of course use a large cap in series with the driver. Any other precautions to take? Nice to hear you enjoyed other Pass constructions, they seem to be well thought of at the forums I've browsed.
What amp are powering your mids and higs today?

B.R,

Jakob

[yggdrasil]

It doesn't matter if the eq is active or passive. Active compensation requires just as much power as the same amount of passive compensation.

A small DC should be fine, but as you say a cap in series will remove it.

Today I use the Zen 9 for mid / high.


Johnny

[Jakob]

I'm not really getting the power requirements. Please bear with me.
If I'm cutting the horndriver -18dB all over its range and the sensitivity is 110dB/1W/1m. Doesn't that mean that the amp only need to put out about 8mW to produce 92dB?
I do understand why boosting a driver means extra need for power, but not the opposite.

What power do I need to look for not risking to overdrive amp and damage driver at 120dB?

Kind regards,

Jakob

[yggdrasil]

What power do I need to look for not risking to overdrive amp and damage driver at 120dB?

It depends on the actual response your drivers have, with your horns, in your room.

Your calculations are good, provided the response is close to flat.


Johnny