I’ve had this build on the back burner for a few months now due to supply chain issues. Now that the parts are in stock, it’s time to start building!
The goal is a (yet another) relatively compact table radio with battery power and Bluetooth with an F3 ~55Hz. This is for a family member that doesn’t have a very good ear, so I’m not aiming for super high fidelity, but just something that sounds pleasing for rock and country and low volumes (~60dB @ 1m). Kind of like a DIY stereo Sonos One.
The drivers I’ve chosen are:
ND91-4
ND16FA-6
ND90-PR
Outside dimensions are about 12.75”x6”x6.5” WHD. Separate enclosures for left and right channels, plus a separate enclosure for the batteries and amplifier that will have some air ventilation.
I’ve also ordered measurement equipment so I can get the specs and responses of the actual mounted drivers.
In WinISD I’ve modelled an F3 of 55Hz with 1.5L for each woofer and 17g added to the PRs, plus a sharp EQ and high pass. The intention is to roll off the EQ as the volume increases to protect the drivers.
Some questions I have for folks here:
Power handling admittedly isn’t great - the woofer hits Xmax at 2.5W and 87dB. With 6.5W the PR hits Xmax and the woofer has 7mm peak excursion. My thinking is between the low listening levels, the adaptive EQ, and the generous Xmech that it should be okay. If it’s flawed thinking I’m all ears!
Note the CAD model is missing the top and bottom panels to see the internal structure. I'm planning on making the bottom panel removable for servicing the components.
Build updates to come as I chip away at this project.
The goal is a (yet another) relatively compact table radio with battery power and Bluetooth with an F3 ~55Hz. This is for a family member that doesn’t have a very good ear, so I’m not aiming for super high fidelity, but just something that sounds pleasing for rock and country and low volumes (~60dB @ 1m). Kind of like a DIY stereo Sonos One.
The drivers I’ve chosen are:
ND91-4
ND16FA-6
ND90-PR
Outside dimensions are about 12.75”x6”x6.5” WHD. Separate enclosures for left and right channels, plus a separate enclosure for the batteries and amplifier that will have some air ventilation.
I’ve also ordered measurement equipment so I can get the specs and responses of the actual mounted drivers.
In WinISD I’ve modelled an F3 of 55Hz with 1.5L for each woofer and 17g added to the PRs, plus a sharp EQ and high pass. The intention is to roll off the EQ as the volume increases to protect the drivers.
Some questions I have for folks here:
- For those who have listened to the ND91-4, how do they sound when they go past Xmax? I figure since their Xmech is so heavily advertised it must be somewhat usable. I’ve opted for tuning for more excursion on the woofer than the PR for this reason.
- Some sims in VituixCAD show a pretty strong directivity mismatch between the woofer and tweeter when the cross anywhere between 3.5K and 5K. Given its intended use, how much should I be worried about it?
- Since I have it on hand and I’d like the speaker to stay compact, I was thinking of using some 3/8” G1S plywood I have. I’m not sure about voids and how resonant it will be. Should I switch to laminating multiple layers of 1/4" or 1/8" MDF / hardboard? Or would the on-hand plywood be okay? I’d be open to trying a CLD approach if it's worthwhile.
Power handling admittedly isn’t great - the woofer hits Xmax at 2.5W and 87dB. With 6.5W the PR hits Xmax and the woofer has 7mm peak excursion. My thinking is between the low listening levels, the adaptive EQ, and the generous Xmech that it should be okay. If it’s flawed thinking I’m all ears!
Note the CAD model is missing the top and bottom panels to see the internal structure. I'm planning on making the bottom panel removable for servicing the components.
Build updates to come as I chip away at this project.
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