Hello,
I have a pair of Dayton Audio PS 220, that I purchased a couple of months ago. I have just put them into their ported box to start the break-in process. I have been quite interested in building the Metronome enclosures, and I plan on doing so, soon, with the PS 220.
My challenge is the exact measurements. I have looked over the page for the Metronome, on Planet 10's site, and the plan they show for the Hemp FR8 is listed. I have compared the T/S parameters, and these speakers specs are incredibly similar.
So, I am wondering if anyone might have the exact panel dimensions and angles???
Thank you in advance.
I have a pair of Dayton Audio PS 220, that I purchased a couple of months ago. I have just put them into their ported box to start the break-in process. I have been quite interested in building the Metronome enclosures, and I plan on doing so, soon, with the PS 220.
My challenge is the exact measurements. I have looked over the page for the Metronome, on Planet 10's site, and the plan they show for the Hemp FR8 is listed. I have compared the T/S parameters, and these speakers specs are incredibly similar.
So, I am wondering if anyone might have the exact panel dimensions and angles???
Thank you in advance.
What Dave says.
It might be OK in FR8 design, but it might not. Specs are similar, but the Dayton is a bit more over-damped. If using a tube amp, that could approximately make up the difference. You'll need a filter to correct the rising response in any case. This stuff is more complicated that it might seem at first. Expect to do some work.
Transmission Line | Leonard Audio
It might be OK in FR8 design, but it might not. Specs are similar, but the Dayton is a bit more over-damped. If using a tube amp, that could approximately make up the difference. You'll need a filter to correct the rising response in any case. This stuff is more complicated that it might seem at first. Expect to do some work.
Transmission Line | Leonard Audio
Hi Guys,
Thank you for your responses. XRK971, I would greatly appreciate that, a lot.
I have done a ton of reading surrounding this over the last 4 months, and, of course, I have read a bunch of very, very informative posts by Dave and the rest of your experienced guys.
I will now shut up, and listen.
Thank you for your responses. XRK971, I would greatly appreciate that, a lot.
I have done a ton of reading surrounding this over the last 4 months, and, of course, I have read a bunch of very, very informative posts by Dave and the rest of your experienced guys.
I will now shut up, and listen.
Greets!
Technically, the Hemp8 Met is too small based on published specs, though if in a small room or up against a wall it's probably fine since it mainly just has a good mid-bass, but scaling it up [1:12.14] to a 1500 cm^2 SL = a 123.56 cm^2 SO yields a flat response to ~42 Hz, hence more tuning flexibility. For flattest response based on published specs, use a 75 cm^2 x 3.8 cm long vent.
GM
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Design for PS220-8 in Met-like Obelisk
The design I arrived at is tuned to 55Hz which should get you a good kick drum fundamental. It is 90dB sensitive (after baffle step losses) and has an f3 of 52Hz. The baffle suffers from a lot of baffle step losses so a BSC is needed (1.6mH + 8R in parallel), the baffle also produces a diffraction bump that is quite large in the mid upper bass from 350Hz to 700Hz. So, optionally, you can add this notch circuit to tame it: 2.0mH + 7.2R + 68uF (all in parallel and connected in series with the BSC, I put it before the BSC). With all these passives in place you have a relatively flat +/-2dB response from 55Hz on up (not accounting for the driver's inherent response variations like breakup peaks etc). I think anytime you can get a single full range driver to hit 90dB at 60Hz, you are doing very good. Use a non-polar electrolytic for the 68uF (or a motor run industrial oil-filled cap if you don't like electrolytics).
Here is the physical design:
Base is 14.0in wide x 6.0in deep
Top is 5.0in wide x 1.5in deep
60.0in tall with driver at 30.0in from top
vent is 4 in sch 40 PVC (4.0in ID) x 2.0in long mounted on bottom and sitting on 2in tall legs to allow vent to escape.
Add moderate polyfill or fiberglass/rockwool stuffing above driver, and line at least 2 adjacent walls below driver with felt or denim carpet insulation pad. Altenatively, *very* loose teased out polyfill wads can be placed below driver.
Predicted response for speaker far from walls (ignore ripples above 300Hz - the stuffing and wall liner will take care of that as it is not modeled):
If you place it too close to a wall (like 2 ft), you get some suck-out at 130Hz:
If you ran it full range with no BSC and no notch filter, you may get something closer to this (far from walls):
If you ignore wall/floor reflections and baffle step losses, no diffraction, you get this (and no BSC or notch circuit):
The design I arrived at is tuned to 55Hz which should get you a good kick drum fundamental. It is 90dB sensitive (after baffle step losses) and has an f3 of 52Hz. The baffle suffers from a lot of baffle step losses so a BSC is needed (1.6mH + 8R in parallel), the baffle also produces a diffraction bump that is quite large in the mid upper bass from 350Hz to 700Hz. So, optionally, you can add this notch circuit to tame it: 2.0mH + 7.2R + 68uF (all in parallel and connected in series with the BSC, I put it before the BSC). With all these passives in place you have a relatively flat +/-2dB response from 55Hz on up (not accounting for the driver's inherent response variations like breakup peaks etc). I think anytime you can get a single full range driver to hit 90dB at 60Hz, you are doing very good. Use a non-polar electrolytic for the 68uF (or a motor run industrial oil-filled cap if you don't like electrolytics).
Here is the physical design:
Base is 14.0in wide x 6.0in deep
Top is 5.0in wide x 1.5in deep
60.0in tall with driver at 30.0in from top
vent is 4 in sch 40 PVC (4.0in ID) x 2.0in long mounted on bottom and sitting on 2in tall legs to allow vent to escape.
Add moderate polyfill or fiberglass/rockwool stuffing above driver, and line at least 2 adjacent walls below driver with felt or denim carpet insulation pad. Altenatively, *very* loose teased out polyfill wads can be placed below driver.
Predicted response for speaker far from walls (ignore ripples above 300Hz - the stuffing and wall liner will take care of that as it is not modeled):
If you place it too close to a wall (like 2 ft), you get some suck-out at 130Hz:
If you ran it full range with no BSC and no notch filter, you may get something closer to this (far from walls):
If you ignore wall/floor reflections and baffle step losses, no diffraction, you get this (and no BSC or notch circuit):
Attachments
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Hi XRK971,
I can't think how to express myself, regarding your work, other than to say Thank You.
I do have one question of clarification. I take it that the measurements for the Top, Base and Height are internal?
Thank you, once again.
You are welcome. Keep us posted on the build. Yes, internal dimensions.
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