[eyrepm]

Hello.

I've recently tried upgrading my Zu Audio Omen DW speakers. Zu generally uses a full range driver + tweeter. They generally use 2 types of tweeters: Eminence ASD 1001 and Radian 850PB. I have the former, which is much cheaper. They are both screw on compression drivers. With the Eminence you have 1 capacitor. The Radian has the exact same capacitor + an L-pad (2 resistors). The FRD has the audio signal coming directly in without a crossover.

I reasoned, and also a user on Audiogon, that you could use a similar but smaller tweeter from Radian to do an upgrade. I used a smaller tweeter, the Radian 475PB, since my speaker has a smaller horn, and so I didn't have to change that or modify the cabinet. Except for this driver, everything else is the same as Zu uses in their high frequency network in their higher end speakers. At least according to my research.

Result:
- Put in 475s with adaptors + cap + a calculated set of resistors
- Sounds like crap

To try to describe it better:
- The sound loses life and fullness
- The overall feel as that this is a real downer
- A comparison could be that you've gone from a fine speaker + amp combo to a really bad one.

Notes:
- I've tried copying their high pass network to a T, except for the smaller driver
- The frequency response curve is fine
- Both the initial and replacement tweeters are 8 ohms
- The resistor wattage and cap values are the exact same as Zu uses

Considering selling the drivers since they make things worse. Also, please excuse me if I'm breaking any forum rules now.

What have I done wrong?

[eyrepm]

This is a link to a folder of specs for all of these things.
https://www.dropbox.com/sh/oyoqm11yjm1q4yd/AAD-qBqx0nrY7mRc9ELNAiJFa?dl=0

This shows my speaker, the Omen, and a higher end one, Soul Supreme. There's also fact sheets for all three drivers in question.

I don't have good measurements now, but I can make some via an UMIK-1.

[richidoo]

The original tweeter was Eminence ASD:1001


The replacement tweeter is Radian 475PB


Main reasons it sounds bad:  the two compression drivers have very different frequency response curve shapes, and they have very different sensitivity. The crossover is valid only for the Eminence driver. It will flatten out the bumpy response and match the level to the woofer. The unchanged crossover driving the Radian will play at least 6dB (2x) louder overall, and will be especially loud near 1kHz where Radian is 18dB louder than Eminence. That's what sounds like crap.

Your 2 possible solutions:
Replace the radian with new eminence drivers (matched from Zu) to restore factory performance.
Change the crossover to accommodate the Radian driver.

If Zu does use Radian drivers, then maybe they already have a crossover for 475PB with the FRD. You could contact them about buying those crossovers, talking about the feasibility of it. See whether the Radian actually works inside their Eminence-optimized waveguide.

You mention the Radian 850PB, but that is 2" throat diameter so it is totally incompatible with this speaker which has a 1" throat diameter waveguide. I doubt Zu would sell you the 2" waveguide without the rest of the speaker.

fwiw, having done a lot of DIY and mods, I'm of the mind now that modding is rarely the best path forward. My advice is to repair the Zus as stock, sell them and upgrade to the Zu Soul Supreme or whatever speakers that have the higher performance that you want.

[eyrepm]

The original tweeter was Eminence ....

Yeah, I'm thinking the same thing; just stop this mess.

Right now I have reversed them to the Eminence ones, so they're fine like that. I might sell the Radians now. They do sell the larger waveguides (that's the aluminium part you screw them into, right?) in their DIY section, which is how I got rolling with these thoughts. Those require irreversible woodwork though.

Also, I talked to them about 475, and they didn't want to pursue that + had no experience with it. Also spoke with Radian about using that waveguide + adapter + the 475, and they said performance-wise that would be fine, in an isolated sense (disregarding crossover, the rest of the speaker, etc).