This DAEX25VT-4 is essentially a tiny driver that you stick to a panel like a foam core board. When music is played, it vibrates the board like a normal cone will vibrate. What kind of sound will it produced? Is it really Hi-Fi?
Wharfedale NXT Panel
Fig 1 – Wharfedale NXT WXT-04/PL
It all started in the 90s when Wharfedale launched the NXT to much fanfare. I bought one of them out of curiosity. It was a 24″x24″ panel with a small transducer glued at the back. This particular model was meant to replace a standard ceiling tile. I supposed it was targeted at ceiling speakers. I never got to testing it because by the time I did, which was years later, I discovered that there’s simply no sound. Perhaps the transducer was broken or I was sold a dud. I don’t really know. I put it aside and it stayed hidden for 20 years.
Now that Dayton is offering audio exciters, it would be a splendid idea to recycle my NXT panel. I removed the original transducer and glued the DAEX25VT-4 in it’s place. It would be roughly what the NXT panel would sound like.
Fig 2 – RAW response of DAEX25VT-4 on NXT WXT panel. No smoothing.
I was quite horrified with the RAW frequency response (Fig 2). What concerns me most are not the cancellations but the huge bump at 500Hz. When I played some music with it, my worse fears were spot on. The honking was quite pronounced in the vocals. There’s no way this is going to beat a ceiling speaker. To make matters worse, the original NXT Panel was more expensive. Maybe that’s why it eventually died a natural death. So much for all the hype.
Is the DAEX25VT-4 any good?
Fig 3 – DAEX25VT-4 with EQ. Smoothed 1/24 octave.
Well, it’s definitely not Hi-Fi. But that doesn’t mean the DAEX25VT-4 is junk. It works. Just that the music is quite unrefined. The easiest way to improve the sound is by equalization. In Fig 3, I used the graphic equalizer from my Foobar2000 to lower the 500Hz region by -10dB. The honking disappeared. It is still not Hi-Fi but at least listenable.
Can it be used?
Of course. Especially in situations where speakers must be unobtrusive. A waiting room in a hospital is a good example. I’ve seen pictures of landscapes, forest, nature and the likes on walls. They help to calm the patients. These prints can be mounted onto foam core boards with exciters stuck onto the back. You can have birds singing or sound of water emitting from them. This will make a huge difference to patients who are emotionally distressed.
DAEX25VT-4 for Music
For music reproduction, it’s imperative to add subwoofers. For places like 5-star restaurants, the subs can be made discreet by having a down firing woofer or a bandpass. The sound quality will surpass ceiling speakers.
I can attest to this because I am listening to the DAEX25VT-4 with my Peerless 830869. For a quick test, I inserted a 3mH for the woofer and a 10Ω resistor to pad down the panel. You don’t need to use an expensive woofer like the 830869. Any cheap woofer will do. It’s only out of convenience since the Peerless is right in front of me.
If I want to improve it further, I’ll simply add a cheap tweeter. That will elevate the music to a new level.
Note: Mic at 24 inches, on axis. Impulse Window=5msec.
July 1, 2020HIFI DRIVERS, Projects