dual 4 ohm voice coil

i have a jensen jpa285 amp 2/1 channel 85rmsx2 into 4ohm 125rmsx2 into 2ohm 250rmsx1 into 4ohm dynamic power 425x1 bridged into 4ohm i just got a pioneer DVC 4ohm sub on the back of the amp it says do not use 2ohm speaker load in bridged mode? how do i best wire this sub it is 350rms 1000peak and i want to get as much from my amp as possible (christmas present from my kids) i see there is a way to wire my dvc that will make 2ohm but isnt that what im not suppose to do? and another shows a 8ohm wiring config. what do i do.. your help is greatly appreciated.

I would wire the coils in series for 8 ohms and bridge the amp.  The power difference is only 170 vs 250 which isn't significant, and using only one coil brings a lot of other factors into the equation that aren't worth dealing with.  In the meantime - you can shop for a decent SVC 4 or DVC 2.

One voice coil. Bad Idea. Isn’t the object here to achieve the best possible efficiency? In the event that your sub is one that performs well in a vented enclosure you might be able to take advantage of its displacement limited power output factor in a vented enclosure. In other words you might be able to use an enclosure that is so efficient that a fraction of typical power will be required in order to obtain maximum performance. Of coarse exact model and year are needed in order to determine this.

thanks i really appreciate your input and fast response.

would i be better off with a single 4ohm. or a dual 2ohm?

im looking at the pioneer premier TS-W1007D2

speakermakers wrote: One voice coil. Bad Idea. Isn’t the object here to achieve the best possible efficiency?

Why? Why a "bad idea"? Perfectly safe, and acceptable to do so. Dan wiggins of Adire Audio said so, and I have two driver engineer friends at Harman International in Northridge that say it's OK to do so as well... Do you know something that THEY don't? DVC wooers will work perfectly well with one voice coil not connected - either open or shorted. The biggest thing is to de-rate the power capacity of the woofer, and you will change the Qms a bit, but there is no reason he can't do this. Additionally, the OP has provided us with all the information we need to have, to determine whether this woofer will work safely with the amplifier available, but with only one voice coil used. See the last paragraph. Read it, and I'll show you that running only one voice coil, in this case IS the best efficiency.

speakermakers wrote: In the event that your sub is one that performs well in a vented enclosure you might be able to take advantage of its displacement limited power output factor in a vented enclosure. In other words you might be able to use an enclosure that is so efficient that a fraction of typical power will be required in order to obtain maximum performance. Of coarse exact model and year are needed in order to determine this.

Even if he were to wire the voice coils in series, for an 8 ohm load, then bridge the amplifier to it, he would achieve an equivalent load of 4 ohms per channel, making 170WRMS for the woofer. The total output difference between 170WRMS and 250WRMS will be less than 3dB, probably even less than 2dB, (I actually figure somewhere around 1.5dB difference - not even noticeable to 99+% of the poulation) there is no reason to push the amplifier as hard as he can. In fact, the amplifier will run cooler, (longer life) with lower distortion (better sound) and higher damping (more control). Granted, the damping thing is theoretical as far as the additional control, but the damping WILL improve. I do agree, that a vented enclosure is probably the best course of action, and that exact woofer model numbers are necessary, car model and year... not QUITE so much.

cycomike wrote: i have a jensen jpa285 amp 2/1 channel 85rmsx2 into 4ohm 125rmsx2 into 2ohm 250rmsx1 into 4ohm dynamic power 425x1 bridged into 4ohm i just got a pioneer DVC 4ohm sub on the back of the amp it says do not use 2ohm speaker load in bridged mode? how do i best wire this sub it is 350rms 1000peak and i want to get as much from my amp as possible (christmas present from my kids) i see there is a way to wire my dvc that will make 2ohm but isnt that what im not suppose to do? and another shows a 8ohm wiring config. what do i do.. your help is greatly appreciated.

Your woofer is rated 350 watts. I derate 25% when only running one voice coil. Charles, John, and Dan say to derate 10-15%, but we'll use my example, as it will "cripple" to the maximum extent. 350 - 25% = 262.5 350 - 10% = 315 Your woofer will safely handle between 262 and 315 watts (depending on the de-rate factor you want to use) while using only one voice coil. That one voice coil is rated as a 4 ohm nominal load. Your amplifier will bridge safely into a 4 ohm nominal load, providing 250 watts RMS at that load. 250 watts output DOES fit within the safe nominal power handling input of 262 watts, right? Run only one voice coil, (4 ohms) bridge it to the amplifier, (250 watts) and you WILL get as much output as that combination can possibly provide you, and be perfectly safe doing so, both in load on the amplifier as well as power input to the woofer.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

now that ive gotten you guys all riled up. would it be better to go with a dual voice coil 2 ohm i just ordered that dvc4 ohm last night order isnt processed yet

The 2 ohm option is usable, but you can only go one of two ways: Wire in series, for 4 ohms, then bridge the amplifier (mono mode) Wire one voice coil to each channel of the amplifier (stereo mode) The 4 ohm option can go the SAME ways, but you can also use the option I have already described to you. If you ALREADY HAVE the 4 ohm woofer, (which your opening post SAYS you have...) just use it, wire it up with one voice coil, and be done... You'll be perfectly safe doing so.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."