Hi there,
I want to build a boombox-style all integrated internet radio. I already have all the parts: screen, SBC, amp, DAC, 2 full range drivers and 2 passive radiators. So basically all the electronic parts and the screen will sit in the middle of the box and the speakers on each side with the passive radiators on their back. My question is: is it better to have each speaker with its passive radiator in a sealed compartment, basically acting as two separate speakers, or have an all open box, as you often see in bluetooth speaker builds. I am basically wondering if it's better to have more volume for the speakers through an open box, but then I wonder if the two radiators would not interfere which each other when the air inside the box is moved by both drivers? Thanks 🙂
I want to build a boombox-style all integrated internet radio. I already have all the parts: screen, SBC, amp, DAC, 2 full range drivers and 2 passive radiators. So basically all the electronic parts and the screen will sit in the middle of the box and the speakers on each side with the passive radiators on their back. My question is: is it better to have each speaker with its passive radiator in a sealed compartment, basically acting as two separate speakers, or have an all open box, as you often see in bluetooth speaker builds. I am basically wondering if it's better to have more volume for the speakers through an open box, but then I wonder if the two radiators would not interfere which each other when the air inside the box is moved by both drivers? Thanks 🙂
Consider the size of the WLs (~344 m_sec/WL) and you'll 'see' that there will be a ~uniform particle density, ergo not an issue unless tuned very high and/or your 'boombox' is a large motor vehicle. 😉
Hi GM, thanks for your reply 🙂 I'm not sure I understand exactly what you are saying about "WL" (wavelenght?) and particle density (I'm pretty new to DIY audio), but you are saying that an open box should not be an issue if I understand correctly, right? But which would actually be preferable, sealed speaker compartments or open box? For reference, I'm using 3" speakers and 3.5" radiators and the box will be roughly 16x6x5 inches...
Right, 'sound is round' (spherical); for example the diameter of a 100 Hz WL is 344/pi/100 = ~1.1 m, so pretty sure one won't fit inside your box, much less two, so you'd have to grind them up to however fine a powder as it takes to fit in the box, but if it still won't, then you'll have to compact it = ~uniform particle density, so going lower in frequency just forces even more compacting.
Re open box better, it's highly likely, but ultimately depends on the driver's, PR's specs and desired tuning (Fb), so please post what you bought.
Re open box better, it's highly likely, but ultimately depends on the driver's, PR's specs and desired tuning (Fb), so please post what you bought.
I have Dayton Audio PC83-4 3" drivers and Peerless by Tymphany 830878 3-1/2" Passive Radiators... Thanks 🙂
OK, a max flat alignment for (2) drivers = ~10.38 L/0.367 ft^3 net volume (Vb) tuned to ~ 60.7 Hz (Fb), so larger it's under damped/could sound a bit 'loose' and smaller a bit peaky in the mid-bass, lower mids, i.e. a typical boombox sound.
net volume (Vb) (L) = 20*Vas*Qts'^3.3
box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
net volume (Vb) (L) = 20*Vas*Qts'^3.3
box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96
Hmm, just looked closer at the PR's specs and not sure it will work with your driver and not set up to sim them ATM, so best to ask P.E..
Enhanced stereo separation requires isolated speakers.
And something like a screen can be blurred or distorted by back waves from bass.
And something like a screen can be blurred or distorted by back waves from bass.
@wiseoldtech, that's a good point.
@GM, I chose those PRs mainly for their xmax value, which, I read, should be at least twice that of the driver. The PR has 6mm vs the driver has 2mm. What makes you think that they may not work?
Also, for the record, this will be a web radio for our kitchen. It's doesn't need to have audiophile sound quality, but it will always be infinitely better than our current radio, I'm sure... 😛
Anyhow, I think I will build some test enclosures first, that's the best way to test the sound.
Thanks. 🙂
@GM, I chose those PRs mainly for their xmax value, which, I read, should be at least twice that of the driver. The PR has 6mm vs the driver has 2mm. What makes you think that they may not work?
Also, for the record, this will be a web radio for our kitchen. It's doesn't need to have audiophile sound quality, but it will always be infinitely better than our current radio, I'm sure... 😛
Anyhow, I think I will build some test enclosures first, that's the best way to test the sound.
Thanks. 🙂