Stereo Upgrade
Elder User
Joined: Mar 2012
Posts: 711
Likes: 2
From: Outside of Memphis, TN
Conversion van. All bets are out the window. Once a converter gets a hold of a van you can fully expect not a single thing in the interior electrical system is unmolested.
If I were setting up a conversion van for a new headunit, I would pull the current one out and check for splices/shorts/hidden amps/addon speakers. Easiest way to do this is set a multimeter to resistance measuring and measure the speaker wires at the back of the factory headunit with the radio unplugged. If you get 2 or 4 ohms, then you should be okay. If you start measuring strange resistances like 0 or 600+, then you will need to find the amplifier/switch/splice and remove it or reuse it as appropriate.
Based on my prior, personal experience with older (early 90's) MK III conversions, I would just pull the interior trim and run fresh 14 or 12 gauge wire from the headunit (or amp location) to the speakers. The speaker wires are often split/scotchlocked/joined in so many strange places that are hard to find its just not worth it. I found one that had 4 speakers on the left rear channel, 2 speakers on right rear, one on the left front, and none on the right front. And it was built that way.
If I were setting up a conversion van for a new headunit, I would pull the current one out and check for splices/shorts/hidden amps/addon speakers. Easiest way to do this is set a multimeter to resistance measuring and measure the speaker wires at the back of the factory headunit with the radio unplugged. If you get 2 or 4 ohms, then you should be okay. If you start measuring strange resistances like 0 or 600+, then you will need to find the amplifier/switch/splice and remove it or reuse it as appropriate.
Based on my prior, personal experience with older (early 90's) MK III conversions, I would just pull the interior trim and run fresh 14 or 12 gauge wire from the headunit (or amp location) to the speakers. The speaker wires are often split/scotchlocked/joined in so many strange places that are hard to find its just not worth it. I found one that had 4 speakers on the left rear channel, 2 speakers on right rear, one on the left front, and none on the right front. And it was built that way.
Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
I take it, the rear and middle speakers are wired together, is it parallel or series, I would like to know the ohm result, I've been considering disconnecting the speakers in the rear doors, wouldn't that correct it to single on each side. I've blown the mid speakers again, has distortion, they are on an amp, hooked to the factory wiring up front, as I said, soon I plan to toss the rear door speakers.
Junior User
Joined: May 2012
Posts: 74
Likes: 0
From: Philadelphia Area
Conversion van. All bets are out the window. Once a converter gets a hold of a van you can fully expect not a single thing in the interior electrical system is unmolested.
Based on my prior, personal experience with older (early 90's) MK III conversions, I would just pull the interior trim and run fresh 14 or 12 gauge wire from the headunit (or amp location) to the speakers. The speaker wires are often split/scotchlocked/joined in so many strange places that are hard to find its just not worth it.
Based on my prior, personal experience with older (early 90's) MK III conversions, I would just pull the interior trim and run fresh 14 or 12 gauge wire from the headunit (or amp location) to the speakers. The speaker wires are often split/scotchlocked/joined in so many strange places that are hard to find its just not worth it.
Fleet Owner
Joined: Aug 2010
Posts: 21,255
Likes: 1,656
From: Reynoldsburg, Ohio
I take it, the rear and middle speakers are wired together, is it parallel or series, I would like to know the ohm result, I've been considering disconnecting the speakers in the rear doors, wouldn't that correct it to single on each side. I've blown the mid speakers again, has distortion, they are on an amp, hooked to the factory wiring up front, as I said, soon I plan to toss the rear door speakers.
Typically head units in cars/trucks have separate circuits for rear speakers so they can be blended or faded if/when needed. As such they have separate circuits in the head unit itself. Wiring additional speakers into an existing circuit in parallel (the only way recommended!) lowers speaker impedance too far below what the power amp can safely "see". This can result in a blown head unit.
Not really sure how a six speaker set up aka conversion vans but my guess is those are not factory/OEM stereos
Removing or unplugging both rear speakers in a factory set-up shouldn't affect the head unit assuming you have the fade function set to full front. Currently I'm running a Sony unit that once had rear speakers but now removed---its fine as it is, the fade function set full to front only.
HTH
Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
This IS OEM and NOT a conversion van, my van is a 15 passenger van, built by Ford, the only modifications are the ones I've made, I can only guess the rear is tied to the middle speakers because if you fade to the rear, they are on, the front doors go out. I ran speaker wires from the dash to under the passenger seat to a 4 channel amp, tying into the factory wiring where the head unit once connected, I didn't want them on my Pioneer unit. I constantly have the rear and middle speakers blowing out the voice coils and I'm getting frustrated, it's costly, the amp and speakers are rated together, and before I installed it in the van, it worked flawlessly in the car.
Junior User
Joined: May 2012
Posts: 74
Likes: 0
From: Philadelphia Area
Some Ford vans (including my 98 XLT RV-prep cargo van) came stock with six speakers run by the OEM headunit. Two in front on their own channel, and two in the middle wired in parallel with two in the rear doors. Somehow the OEM headunit was set up to handle the impedance issues, but aftermarket headunits can have problems with the changed impedance.
If all six of your speakers play off the headunit, you can tell if the center and rears are wired in parallel by using the fader on your headnunit. Simply fade all the way to the rear and see if the center speakers are also still playing. If so, they are wired in parallel with the rear.
I put in an aftermarket Kenwood in my van and ran into impedance issues, with the sound breaking up or distorting. I've disconnected the center speakers until I can figure out a way to fix the problem.
If all six of your speakers play off the headunit, you can tell if the center and rears are wired in parallel by using the fader on your headnunit. Simply fade all the way to the rear and see if the center speakers are also still playing. If so, they are wired in parallel with the rear.
I put in an aftermarket Kenwood in my van and ran into impedance issues, with the sound breaking up or distorting. I've disconnected the center speakers until I can figure out a way to fix the problem.
Junior User
Joined: May 2012
Posts: 74
Likes: 0
From: Philadelphia Area
Sorry, didn't fully read the previous posts. But maybe the stuff I posted above will help some folks.
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Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
I have no rear seats, built a deck back behind the seat that is over the axle, drop to bed, put a pad on the deck for a full size bed, subwoofer under it, the back doors are far from the seat, would be OK if I had 4 8-OHM speakers. I need 8 OHM speakers since I have 4 blown ones I guess.
Cargo Master
Joined: Sep 2012
Posts: 2,112
Likes: 286
From: Eastern TN
Is the amp getting line level or speaker level inputs from the stereo? If speaker level, maybe it's at a higher level than the amp can manage. Does the amp have input gain settings that might have been changed from when it was in another car? I suppose the amp input can be so distorted as to overwhelm the speakers but I imagine it would overwhelm your ears far sooner.
I didn't find anything online about insufficient impedance being detrimental to speakers; it's detrimental to the amp. The consensus seems to be that voice coils give up from too much power. Maybe you're running more power for the same sound volume at your ears because the van has a far bigger cabin than the car in which you had the system previously.
Maybe we need to learn more about the amp and speakers being "rated together."
Sixto
93 E150 Chateau 5.8 185K miles
I didn't find anything online about insufficient impedance being detrimental to speakers; it's detrimental to the amp. The consensus seems to be that voice coils give up from too much power. Maybe you're running more power for the same sound volume at your ears because the van has a far bigger cabin than the car in which you had the system previously.
Maybe we need to learn more about the amp and speakers being "rated together."
Sixto
93 E150 Chateau 5.8 185K miles
Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
The amp is a 400x4, which the max RMS on them never peaks at the max, it's about 75 watts, speakers are rated for 100 watts, thats what I mean "rated together."
I never use speaker terminal high inputs on an amp, I have it on the head unit VIA RCA cables, the gain is less than half on the dial. Look, my issue is the rear, the front of the amp is on the same speakers that I installed with the amp with the gain, and setting the same as the rear, but the rear keep blowing the voice coils. So, the Ohm on the rear speakers must be different than the front, having 4 speakers on the same 2 rear channels, speakers being 4 Ohm, if you can understand what I'm getting at, maybe you'll see the rating is a moot point here.
An amp at 2 Ohm, will increase the wattage in most occasions, if it's 2 Ohm stable, so I need to know how the rear speakers are wired in. I guess I'm answering my own question and need to jerk the rear door panels and unhook those speakers.
I never use speaker terminal high inputs on an amp, I have it on the head unit VIA RCA cables, the gain is less than half on the dial. Look, my issue is the rear, the front of the amp is on the same speakers that I installed with the amp with the gain, and setting the same as the rear, but the rear keep blowing the voice coils. So, the Ohm on the rear speakers must be different than the front, having 4 speakers on the same 2 rear channels, speakers being 4 Ohm, if you can understand what I'm getting at, maybe you'll see the rating is a moot point here.
An amp at 2 Ohm, will increase the wattage in most occasions, if it's 2 Ohm stable, so I need to know how the rear speakers are wired in. I guess I'm answering my own question and need to jerk the rear door panels and unhook those speakers.
Cargo Master
Joined: Sep 2012
Posts: 2,112
Likes: 286
From: Eastern TN
You say you transplanted a known good system from a car but you don't know if the rear speakers are wired in parallel. I take that to mean you took the amp and 6 speakers from the car, but didn't run new speaker wires. Is this correct?
To determine how the rear pair of speakers are wired, disconnect one speaker and see if the other speaker in the same channel still sounds. If so, they're wired in parallel. If not, they're wired in series. Assuming there isn't a crossover or amp in the mix, anyway.
Sixto
93 E150 Chateau 5.8 185K miles
To determine how the rear pair of speakers are wired, disconnect one speaker and see if the other speaker in the same channel still sounds. If so, they're wired in parallel. If not, they're wired in series. Assuming there isn't a crossover or amp in the mix, anyway.
Sixto
93 E150 Chateau 5.8 185K miles
Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
I pulled the working amp from the car, installed it in the van, then bought new 6x8 speakers rated for the amp, they winded up blowing the voice coils, I decided to upgrade to an even better set, and again, the same end, it's on the factory wiring from the dash. I should have removed the rear as they are far from the seating.
Fleet Owner
Joined: Aug 2010
Posts: 21,255
Likes: 1,656
From: Reynoldsburg, Ohio
Maples see if this info is helpful: Series Parallel Speaker Impedance
I've not read it all the way though but a quick overview says its a good beginning maybe.
HTH
I've not read it all the way though but a quick overview says its a good beginning maybe.
HTH
Lead Driver
Joined: May 2004
Posts: 5,040
Likes: 137
From: Maryville
Maples see if this info is helpful: Series Parallel Speaker Impedance
I've not read it all the way though but a quick overview says its a good beginning maybe.
HTH
I've not read it all the way though but a quick overview says its a good beginning maybe.
HTH
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