hello,
I'm making a 2.4 cu ft with 1 pair of JL Audio 10W3-D4 clamshell isobaric, tune 21Hz 4" circular port.
the speakers have dual coils of 4ohm each. I want to present 4ohm to the amp, how do i connect the speakers' terminals?
1. coils in parallel (2ohm) and speakers in series = 4 ohm
2. coils in series (8ohm) and speakers in parallel = 4 ohm
(WinISD software allows me to select parallel or series for the voice coils but no selection of the speakers' wiring. parallel shows max of 20 ohm @37Hz, series shows max of 80 ohm @ 37Hz.)
3. Also, given the fact that the first resonance of the port is 230Hz (4" x 29" port size) and that the crossover will be set below 70Hz (18dB/oct) should I use some egg crate foam, aprox 2” thick on the inside? the shape is cylindrical for both the enclosure and the port... (sonotube 18" and pvc pipe 4" flared ends)
thanks for your responses.
I'm making a 2.4 cu ft with 1 pair of JL Audio 10W3-D4 clamshell isobaric, tune 21Hz 4" circular port.
the speakers have dual coils of 4ohm each. I want to present 4ohm to the amp, how do i connect the speakers' terminals?
1. coils in parallel (2ohm) and speakers in series = 4 ohm
2. coils in series (8ohm) and speakers in parallel = 4 ohm
(WinISD software allows me to select parallel or series for the voice coils but no selection of the speakers' wiring. parallel shows max of 20 ohm @37Hz, series shows max of 80 ohm @ 37Hz.)
3. Also, given the fact that the first resonance of the port is 230Hz (4" x 29" port size) and that the crossover will be set below 70Hz (18dB/oct) should I use some egg crate foam, aprox 2” thick on the inside? the shape is cylindrical for both the enclosure and the port... (sonotube 18" and pvc pipe 4" flared ends)
thanks for your responses.
Personally from what I’ve read I think the first port resonance is well out of the way to not consider worrying about.
Box regidity shouldn’t be a problem (cylinder)
Wiring is simple wire sub 1’s voice coils in parallel to create 2 ohm load
Do the same for sub 2. Now you have in essence created 1 dual voice coil sub D2.
Then wire both subs in series back to the amp. And you have a 4ohm load.
Look at wiring on google first for 1 DVC sub wired in parallel. Then do it to both.
Then look at wiring for series and wire the subs in series.
Hope it helps.
Box regidity shouldn’t be a problem (cylinder)
Wiring is simple wire sub 1’s voice coils in parallel to create 2 ohm load
Do the same for sub 2. Now you have in essence created 1 dual voice coil sub D2.
Then wire both subs in series back to the amp. And you have a 4ohm load.
Look at wiring on google first for 1 DVC sub wired in parallel. Then do it to both.
Then look at wiring for series and wire the subs in series.
Hope it helps.
thanks @trojantrow
i'm familiar with wiring in series and parallel... my question regards the two options both giving a final 4ohm loads... does the amp see a difference between options (1) and (2)?
option (2) would make it easier to wire the banana speaker terminals since one speaker is inside and one is outside of the enclosure. option (1) requires a wire to go from the outside to the inside of the enclosure as a 'series cable' between the speakers.
i'm familiar with wiring in series and parallel... my question regards the two options both giving a final 4ohm loads... does the amp see a difference between options (1) and (2)?
option (2) would make it easier to wire the banana speaker terminals since one speaker is inside and one is outside of the enclosure. option (1) requires a wire to go from the outside to the inside of the enclosure as a 'series cable' between the speakers.
Wiring the coils of one woofer in series (to 8 ohms) is preferred, as that means the two woofers can be connected in parallel. Amplifiers are voltage sources and a parallel connection means that each woofer gets the same voltage.
If there is a difference in T/S parameters or enclosure between the woofers, this is less of a problem with parallel wiring. Though things like resonancy frequency do not differ when the woofers are mounted cone to cone.
In short: it does not matter for your application.
If there is a difference in T/S parameters or enclosure between the woofers, this is less of a problem with parallel wiring. Though things like resonancy frequency do not differ when the woofers are mounted cone to cone.
In short: it does not matter for your application.
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thank you for your replies.
given the info, I will go with option 2: wire the coils in series and the woofers in parallel.
@troystg: how do you go about making the connections between the drivers if one is inside and one is outside of the enclosure? as i understand your idea, 4 wires need to go from outside to the inside of the enclosure..never thought of that wiring scheme until you mentioned it.
given the info, I will go with option 2: wire the coils in series and the woofers in parallel.
@troystg: how do you go about making the connections between the drivers if one is inside and one is outside of the enclosure? as i understand your idea, 4 wires need to go from outside to the inside of the enclosure..never thought of that wiring scheme until you mentioned it.
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