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Post by barryrobin on Apr 7, 2013 15:43:10 GMT -5
One of my M&K subs just blew it's foam seal, so while it's being refoamed I thought I'd replace it with a temporary driver. Looks like I'll need some quickie advice because i'm a little confused on which OHM to use. The sub runs at 4ohms using two 8ohm drivers in a push-pull configuration. Each driver is listed as 8 Ohm but it has two hookups; one is wired directly into the amp and the other is a patch cord that goes from the first hookup to the second-making it seem like it's wired in series...
All my extra drivers use single hookups...so, do i use a single 4 or 8 ohm driver?
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Post by Deleted on Apr 7, 2013 15:44:54 GMT -5
One of my M&K subs just blew it's foam seal, so while it's being refoamed I thought I'd replace it with a temporary driver. Looks like I'll need some quickie advice because i'm a little confused on which OHM to use. The sub runs at 4ohms using two 8ohm drivers in a push-pull configuration. Each driver is listed as 8 Ohm but it has two hookups; one is wired directly into the amp and the other is a patch cord that goes from the first hookup to the second-making it seem like it's wired in series... All my extra drivers use single hookups...so, do i use a single 4 or 8 ohm driver? The two drivers we're ran in parallel to get the 4ohm load. So use a single 4 ohm driver  |
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Post by barryrobin on Apr 7, 2013 15:51:09 GMT -5
Thanks Matt. My confusion was because each driver is 8ohm, which will give me a 4ohm load. Then why wire each driver twice?
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geebo
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Post by geebo on Apr 7, 2013 15:51:13 GMT -5
One of my M&K subs just blew it's foam seal, so while it's being refoamed I thought I'd replace it with a temporary driver. Looks like I'll need some quickie advice because i'm a little confused on which OHM to use. The sub runs at 4ohms using two 8ohm drivers in a push-pull configuration. Each driver is listed as 8 Ohm but it has two hookups; one is wired directly into the amp and the other is a patch cord that goes from the first hookup to the second-making it seem like it's wired in series... All my extra drivers use single hookups...so, do i use a single 4 or 8 ohm driver? If the amp is connected directly to both terminals on one driver, they're wired in parallel. If series connected, one amp terminal would be connected to one driver's + and the other amp terminal would be connected to the other driver's -. Then the unused driver terminals would be connected together. It sounds like you have a parallel arrangement. You could use either a single 4 or 8 ohm driver. |
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Post by barryrobin on Apr 7, 2013 15:56:18 GMT -5
One of my M&K subs just blew it's foam seal, so while it's being refoamed I thought I'd replace it with a temporary driver. Looks like I'll need some quickie advice because i'm a little confused on which OHM to use. The sub runs at 4ohms using two 8ohm drivers in a push-pull configuration. Each driver is listed as 8 Ohm but it has two hookups; one is wired directly into the amp and the other is a patch cord that goes from the first hookup to the second-making it seem like it's wired in series... All my extra drivers use single hookups...so, do i use a single 4 or 8 ohm driver? If the amp is connected directly to both terminals on one driver, they're wired in parallel. If series connected, one amp terminal would be connected to one driver's + and the other amp terminal would be connected to the other driver's -. Then the unused driver terminals would be connected together. It sounds like you have a parallel arrangement. You could use either a single 4 or 8 ohm driver. Interesting! I know this is all elementary stuff, but the whole M&K push-pull arrangement still sorta baffles me. Thanks guys! |
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geebo
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Post by geebo on Apr 7, 2013 16:03:59 GMT -5
Now in a push-pull configuration, they quite possibly could be wired out of phase. But that wouldn't change whether they are series or parallel connected. Just which drivers terminals are connected to the other's.
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Post by barryrobin on Apr 7, 2013 16:07:45 GMT -5
Now in a push-pull configuration, they quite possibly could be wired out of phase. But that wouldn't change whether they are series or parallel connected. Just which drivers terminals are connected to the other's. They're definately wired out of phase. I guess that I'll just use the single terminal 8ohm to play it safe. |
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Post by garbulky on Apr 7, 2013 16:43:46 GMT -5
Hold up ... are you guys sure about your calculations? Doesn't an 8 + 8 in one config give you 4. But an 8 + 4 give you something less than that? I forgot my series and parralel. I think we have to advice him on which one to use the series or parralel connection and then which driver to use for that. As it seems there are two possible configs here.
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geebo
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Post by geebo on Apr 7, 2013 16:50:57 GMT -5
Hold up ... are you guys sure about your calculations? Doesn't an 8 + 8 in one config give you 4. But an 8 + 4 give you something less than that? I forgot my series and parralel. I think we have to advice him on which one to use the series or parralel connection and then which driver to use for that. As it seems there are two possible configs here. Yes. 1/R1 + 1/R2 = 1/Rtotal so an 8 and a 4 would be 1/8 + 1/4 or 1/8 + 2/8 or 3/8 which when inverted would be 8/3 or 2.66667 ohms. But I don't think that's what the OP was asking. |
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Post by garbulky on Apr 7, 2013 16:53:50 GMT -5
Thanks geebo. I guess I misunderstood. I have to go rest my brain cells. That last calculation of yours made them cry a bit. ;D
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geebo
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Post by geebo on Apr 7, 2013 17:00:19 GMT -5
Incidentally, you can include as many resistance values as you like in the first parts of the formula. ie 1/R1 + 1/R2 + 1/R3 + 1/R4 etc.
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Post by barryrobin on Apr 7, 2013 18:54:22 GMT -5
Hold up ... are you guys sure about your calculations? Doesn't an 8 + 8 in one config give you 4. But an 8 + 4 give you something less than that? I forgot my series and parralel. I think we have to advice him on which one to use the series or parralel connection and then which driver to use for that. As it seems there are two possible configs here. Yes. 1/R1 + 1/R2 = 1/Rtotal so an 8 and a 4 would be 1/8 + 1/4 or 1/8 + 2/8 or 3/8 which when inverted would be 8/3 or 2.66667 ohms. But I don't think that's what the OP was asking. Yup-that's exactly what I was asking about. And yes, my head hurts now too. -B |
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KeithL
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Post by KeithL on Apr 7, 2013 22:15:38 GMT -5
I would suggest you check the specs on your new driver(s). From your description it sounds like you're saying that each driver has four TERMINALS - two of which go to the amplifier and two of which have a jumper between them, right? If so, then your driver almost certainly has TWO VOICE COILS. Each voice coil would be 4 ohms; if you wire them both in series you end up with 8 ohms total; if you wire them both in parallel, you end up with 2 ohms; if you use only one you end up with 4 ohms. Assuming I'm right, and it came with the jumper in place, and the two terminals open, then it is wired for 8 ohms. Some drivers are wired this way to give you the most flexibility (4 ohms or 8 ohms for normal use; 2 ohms might work well with some car amps). If the original drivers are "spec'ed" at 8 ohms, then you use an 8 ohm replacement driver. One of my M&K subs just blew it's foam seal, so while it's being refoamed I thought I'd replace it with a temporary driver. Looks like I'll need some quickie advice because i'm a little confused on which OHM to use. The sub runs at 4ohms using two 8ohm drivers in a push-pull configuration. Each driver is listed as 8 Ohm but it has two hookups; one is wired directly into the amp and the other is a patch cord that goes from the first hookup to the second-making it seem like it's wired in series... All my extra drivers use single hookups...so, do i use a single 4 or 8 ohm driver? |
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Post by Deleted on Apr 8, 2013 0:44:21 GMT -5
Thanks geebo. I guess I misunderstood. I have to go rest my brain cells. That last calculation of yours made them cry a bit. ;D May I suggest?  |
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DYohn
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Post by DYohn on Apr 8, 2013 10:11:52 GMT -5
I suggest that while the surround is being replaced on your woofer that you do not simply stick another woofer in there and hope for the best. You'd be better off waiting for the correct driver to be repaired. Replacing a surround take all of a couple hours... who's doing the repair for you?
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Post by barryrobin on Apr 8, 2013 15:08:34 GMT -5
I suggest that while the surround is being replaced on your woofer that you do not simply stick another woofer in there and hope for the best. You'd be better off waiting for the correct driver to be repaired. Replacing a surround take all of a couple hours... who's doing the repair for you? I'll be sending it off to a place on the west coast called Orange county Sound. It's well-regarded. |
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Post by barryrobin on Apr 8, 2013 15:21:00 GMT -5
...your driver almost certainly has TWO VOICE COILS. Each voice coil would be 4 ohms; if you wire them both in series you end up with 8 ohms total; if you wire them both in parallel, you end up with 2 ohms; if you use only one you end up with 4 ohms. Assuming I'm right, and it came with the jumper in place, and the two terminals open, then it is wired for 8 ohms.] Exactly! Looks like I'll be using a single 8ohm driver. Now, try explaning how a push-pull amp with out of phase drivers has not the stated wattage but twice that because each pulse of the amp gives a full load to each driver as it fires. If the amp has 500 watts then it's not 500 watts divided in two, it's 500 watts for each driver that has the net effect of making it a 1000 amp. Huh? The owner of the company tried explaining it to me and i still don't get it! |
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