Guys
Going to order 2*,ND65's and want to use a peerless 3.5" PR. I realise that it is best to have individual compartments per driver and have a PR that is double the VD. Doing the maths the PR is 5x that which tells me I could theoretically use 1. People on YouTube seem to use 2 to 1, but I realize this could actually click bait, so what is the public opinion one this?
1 driver v 1 PR and individual compartments
Or
2 drivers and 1 PR and shared compartment
Going to order 2*,ND65's and want to use a peerless 3.5" PR. I realise that it is best to have individual compartments per driver and have a PR that is double the VD. Doing the maths the PR is 5x that which tells me I could theoretically use 1. People on YouTube seem to use 2 to 1, but I realize this could actually click bait, so what is the public opinion one this?
1 driver v 1 PR and individual compartments
Or
2 drivers and 1 PR and shared compartment
Sd of the 2 ND65s combined is 31.2 cm2. One Peerless 830878 PR is 50.2 cm2 which is 1.6 times more, not 2 times. Would your cabinet specs allow you to move up to the SDS-P830880 5.25” PR? Its Sd is 87 cm2. The choice of separate compartments would depend on the number of PRs in my opinion.
Edit: Sorry, I focused on Sd, not Vd. With a Vd of 109.2 for the 2 ND65s, using one Dayton Audio DMA80-PR 3" DMA Series Passive Radiator would be exactly 2x Vd.
Edit: Sorry, I focused on Sd, not Vd. With a Vd of 109.2 for the 2 ND65s, using one Dayton Audio DMA80-PR 3" DMA Series Passive Radiator would be exactly 2x Vd.
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its a weird one with incomplete information for the peerless. trawling through the PE tech forums and product reviews i found somebody posted the actual xmax after contacting Peerless (well i believe it so far 🙂 apparently it is 6mm.
so based on that i got a Vd of 301.2 for the PR and one 2.5inch ND65 is 54.6. I'm also not sure what specs to go off as PE shows it being a 3.5inch and other sites saying 4inch.
Also on the PE page a similar question was asked about doing the 2x drivers per radiator combining the enclosure, one of the responses was it was inefficient.
Not really too sure what to believe to be honest.
You can measure Sd by taking diameter from middle of surround rubber roll (apex). Calculate area of a circle based on that.
I'm quite confused, but keen to roll with option 2.
Considering the application being a Bluetooth speaker and potentially battery powered and going to run off 12v I'm keen to keep the footprint down and would like some bass. I see some make these portable configurations with the 2 for.1's and aware it may be inefficient.
I can make the other but I think the size required is getting up there with my other boom box.
I'm thinking of the peerless in that size as it is in stock at my current supplier in Aus, where the matching Dayton's PR's have a longer lead time of weeks, which I'm impatient 🙂
Considering the application being a Bluetooth speaker and potentially battery powered and going to run off 12v I'm keen to keep the footprint down and would like some bass. I see some make these portable configurations with the 2 for.1's and aware it may be inefficient.
I can make the other but I think the size required is getting up there with my other boom box.
I'm thinking of the peerless in that size as it is in stock at my current supplier in Aus, where the matching Dayton's PR's have a longer lead time of weeks, which I'm impatient 🙂
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SB Acoustics make PRs including a couple of 4” and a 5”x8”. They have an Aussie distributor as well. Perhaps worth a look.
Passive Radiators :: SB Acoustics
Distributors :: SB Acoustics
Passive Radiators :: SB Acoustics
Distributors :: SB Acoustics
Most of these passive radiators have an Fs that is too low for use with small drivers. You'll get low bass but the SPL will be too low to be of any use unless it's equalised or use DSP. Vented is much easier and cheaper.
I did a SB65WBAC with a SB12PAC passive radiator and to reach a Fb around 75-80Hz, I had to cut away half the spider.
Model it before purchasing and you'll see what I mean as the bass rolls off steeply.
I did a SB65WBAC with a SB12PAC passive radiator and to reach a Fb around 75-80Hz, I had to cut away half the spider.
Model it before purchasing and you'll see what I mean as the bass rolls off steeply.
Oh right, I have been focusing on sizing the box to tune the speakers as vented, but assumed that in lieu of a port I would use the PR and it would basically mimic but don't actually know how to model it. I found a site that mentioned the required weight but that's it in a nutshell.
any advice on what i would need for a +3db BSC? with the 4ohm ND65's and a baffle width shown above (second option). I still need to figure out how to plug both PR and filter into WiniSD to see what it does.
For winISD, chose your driver and then choose passive radiator under box type. Then enter PR details in next window. I don't think you can add BSC in winISD. Has to be done in an xo program like PCD.
3dB BSC for Re 3R5 for around 125mm effective baffle is 1R2 + 0.22mH (LR circuit) rounded to nearest size.
3dB BSC for Re 3R5 for around 125mm effective baffle is 1R2 + 0.22mH (LR circuit) rounded to nearest size.
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Cheers mate, parts have arrived and had a go with WiniSd, didn't quite do what I expected lol ..... Curve went nuts with what I had
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