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Pathy Amp Info


cham
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The speaker may be rated up to 60W RMS, but that doesn't mean that's what necessary to make them happy. There's no issue running them at a lower RMS, but it would be helpful to know what the Bose (or even stock amps) are putting out. I found a 2002 brochure indicating the base system was 100W and the Bose was 150W. Treating those as cumulative maxes for all amps, I'd say <20W RMS sounds reasonable for the Bose.

 

I don't know if the Scosche unit is stepping things up or down, but it's not very relevant because the system will need to be 'tuned', much like any amp-inclusive aftermarket system. Settings are dependent on the headunit, and there's no magic number; it's about what sounds optimal with the components in the system.

 

I'll add I've never needed anything like the Scosche for any other install any speaker-level OE amp setups I've done. I bought it based on several complaints of low volume across Bose-based Nissans where the headunit was replaced, as well as Crutchfield's assessment of its need. I have no complaints, but I also never baselined it without it.

 

I do think they the fronts are amps because there is a power and ground lead going to them, per the FSM. No other function seems to make sense. I agree there is probably a resistor on the tweeter and that the speaker is full range (it's how my Frontier's stock speakers were).

 

Bottom line is that for cham, the reason for recommending the Scosche unit and aftermarket headunit is because it's the foot in the door and should solve his immediate problem. I totally agree the system could be greatly improved by replacing/bypassing all the OE amps, or even using an aftermarket headunit without amps. But given all the questions, sounds like he still has a lot to learn about system design overall.

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I still think they are cross overs and here's why... I was able to use the factory wiring to install my aftermarket component set. If the input + and - were in fact power and ground, it'd be impossible to make sound. They were labeled input + -, woofer + -, and tweeter + -. Input is a full range signal from the head unit or amplifier. This is standard for a cross over.

 

There could be a year change with a different design and set up.

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Ok I'm a little confused. When I asked the Crutchfield advisors, they said according to their diagrams and such that the bose system for my pathy had 3 factory amps, one in each front door adjacent to the woofer and an amp in the cargo powering the rear speakers like I have said previously. I was also thrown off because leading up to that I thought the system just had crossovers splitting the signal and an amp in the cargo and that was it. With asking around though it seems like you can replace the front amps with a crossover so maybe thats why you were successful in doing so without having problems. Also in your picture, is that the rear amp in the very middle and are those the front amps/crossovers on the left and right? So what I'm asking is, is it worth it to go through all the hassle of replacing the headunit and either replacing the rear amp or bypassing it to get the little extra quality out of the rear speakers? Or will it significant change the quality because I'm guessing you have read this from the previous threads but I used JBL GX602 coaxial 2ohm speakers to replace the rear speakers and they sound good but they just are not loud enough I guess because of an increase in impedance but Im guessing the quality can sound a little better. I'm definitely going to replace the front speakers, since I will be switching the front amps out for crossovers, should I get 4 ohm components because the amp is not there with low ohm output or should I still get 2 ohm components because of the HU?

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IMG_1831.jpg

Here is a photo of one of the rear speakers. Im not sure if this hints as to any information on the speaker's ohm level or RMS wattage so if anyone does know please say so?

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Here's why I'm certain it's an amp (of sorts, or is at least active in some way):

 

Bose_Schematic.jpg

 

Pin #4 on both front speakers is coming from a relay, which has a turn-on signal from the headunit (pin #12), bringing power from the battery (also supplies power to the headunit #6 and rear speaker amp #11; the same turn-on signal goes to the rear amp #9). Pin #5 on the front speakers is the ground. Pins #2 and #6 on the front speakers are the audio signals (#2 is + and #6 is — on the detailed schematics in the FSM).

 

This is all described in the FSM:

 

BOSE SYSTEM
Power is supplied at all times

  • through 15A fuse [No. 4, located in the fuse block (J/B)]
  • to audio unit terminal 6,
  • to audio amp. relay terminal 3,
  • to rear speaker amp. terminal 11 and
  • to AUX box terminal 7 (with rear TV).

With the ignition switch in the ACC or ON position, power is supplied

  • through 10A fuse [No. 10, located in the fuse block (J/B)]
  • to audio unit terminal 10,
  • to AUX box terminal 6 (with rear TV).

Ground is supplied through the case of the audio unit.
Ground is supplied

  • to audio amp. relay terminal 2,
  • to front door speaker LH terminal 5 and
  • to front door speaker RH terminal 5
  • through body grounds M4, M66, M111, M147 and M157
  • to rear speaker amp. terminal 24 and
  • to AUX box terminal 8 (with rear TV)
  • through body grounds B11, B22 and D210
  • to rear TV switch terminal 3
  • through body grounds M4, M66, M111, M147 and M157.

When the audio unit POWER button is pressed, power is supplied to rear speaker amp. terminal 9 and audio
amp. relay terminal 1 from audio unit terminal 12. Then audio amp. relay is energized and power is supplied

  • to front door speaker LH terminal 4 and
  • to front door speaker RH terminal 4.

Audio signals are supplied

  • through audio unit terminals 1, 2, 3, 4, 13, 14, 15 and 16
  • to terminals 2 and 6 of the LH and RH front speakers and terminals 5, 7, 18 and 20 of the rear speaker amp.
  • to LH and RH tweeters through terminals 1 and 3 of the front door speakers
  • to rear LH and RH speakers through terminals 1, 2, 25 and 26 of the rear speaker amp.

 

As I mentioned before, I don't see any reason why you couldn't tap into those signals to feed aftermarket speakers directly from an unplugged harness on the front speakers. If we knew its specs, pins #1 and #3 could be reused to drive the tweeter. It doesn't indicate any pins/wiring for the speaker, so I assume there is a very short set of wires going to the speaker (negligible for the diagrams), or it's some sort of integrated circuit that's soldered directly to the speaker. I can't tell from the pictures I've seen.

Edited by hawairish
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There could be a year change with a different design and set up.

 

This possibly best explains any differences. I didn't know that some models in between only had the rear amp and no front amps. The schematic I've been looking at is for a 2004, so we may both be right depending on MY.

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hawairish, I read the schematic as indicating that the 6-wire plug is plugging directly in to the door speaker. If there is an amplifier there, it's embedded on the speaker itself. That seems unlikely, so what about the possibility that it has an integrated ACTIVE crossover?

 

Now, either way the situation for replacement is the same. New component speakers go in there and get audio input from the head unit and the aftermarket crossover (that matches the components) is placed there in the door.

A very small aftermarket amplifier could be installed, somewhere up under the dash, behind the radio and used to feed the front speakers if desired. There are amps as small as a dollar bill.

 

to the OP: if you replace the front speakers and leave the stock head unit, you will want 2-ohm speakers. If you replace your head unit you will want 4-ohm speakers only. But if you place an aftermarket amp in there to handle those speakers you will have your choice of 2 or 4 ohms.

 

Another thought about your rear speakers being too quiet. Is it possible you have the wires reversed? The direction the current flows through the speakers makes a big difference...it needs to be right.

 

 

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I considered it being an active crossover, but I wouldn't see the benefit of that. It doesn't have any adjustability, and a passive one would be beyond sufficient if so. Any time I've seen an active crossover in place, it's been before an amp (no point in sending a full signal to the amp if you're just going to cut it later).

 

I'd have to take apart the door modules to know what it's doing. Maybe one day.

 

If I were to bypass the amps, it'd be with a single 4-channel. The quality of the speakers I'd use would dictate amp size and whether I'd re-wire things or just run leads back to behind the headunit and use stock wiring from there. I'd keep everything 4-ohm mainly because it opens up more speaker options. But many amps can handle different impedance on different channels, and each channel (or at least fronts vs rears) can have sensitivity set, so keeping those JBLs probably wouldn't be problem.

 

I asked about the wiring polarity earlier, too. Not sure I saw a response. I always check pinouts on harnesses/adapters...I don't usually trust them. But the polarity would make a difference.

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Yeah I'm not sure how to check polarity. Just look inside the harness adapters for what? Are you just looking to see both pins? Also, with having the rear speakers 2 ohm and the front ones 4 ohm with a new HU and no amps up front, will there be a significant difference in sound quality between the front and back of the car? I heard 4 ohm speakers are more bassier than 2 ohm.

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This thread has me almost wanting a stereo again. I stopped doing them after one particular system I made got jacked (custom fiberglass box to replace the jump seat in my Frontier, hidden amps, storage). I spent the insurance money on a lift and tires, and never really bothered since. In fact, any system I've done since has purposely incorporated stock components (more expensive to replace than anything aftermarket to the insurance company).

 

But anyway...see one of my previous posts about the wire colors and polarity. New speakers normally have a connector that's wider than the other...wide is + and narrow is -. But you need to confirm that the + is connected to the + wire on the truck, regardless of the wire being used on the aftermarket harness (if used). I think I said black w/ pink is the - wire.

 

Again, hard to predict sound quality until you have the ability to fully control the system. IMO, this is only possible with a new head unit, or new headunit and aftermarket amp(s). The sensitivity settings on amps are what guarantee you the ability to match front and rear levels.

 

I don't see how impedance correlates with bass, but it's not something I've researched or heard about. The only thing that cares about impedance is the amp driving it. A 4-ohm speaker (or rather, its voice cool) is still a 4-ohm speaker when run in a 2-ohm configuration. I've also seen sub manufacturers produce identically spec'd subs, with the only difference being impedance.

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Yeah I cant wait until I've figured everything and installed it, its going to sound amazing to me. I also plan to out in a powered sub later too and splice in into one of the rear speaker's wire. Ok so I still have a question about the front speaker setup. Since I am potentially going to get rid of the factory amps in the front and put crossovers in place, will adding an aftermarket HU do anything to increase the watts going to the new aftermarket component set making them closer to their true potential quality since the amps are not there? How much wattsRMS do aftermarket HU on average put out because Im wandering if it will be the rated amount that the aftermarket component speakers seek?

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The 6 wires go to the cross over/amp in the door. They do NOT go into the speaker. There's a plastic molded case that holds both the speaker and the cross over together as one nice package.

 

The small black boxes with wires hanging off of them in my picture are the cross overs, the two larger speakers are the fronts.

 

My aftermarket crossovers (Hertz) fit right in the factory enclosure. I had to do a lot of cutting to fit my Audison speakers but most all others fit fine. My aftermarket amp fits in the factory location and even mounts to the existing bracketry for it. Using the factory wiring, it handles all 4 channels.

 

Pulling the door panel off to actually see what's going on is not hard to do instead of guessing at it. It'll make a lot more sense once you do.

 

In all honesty, this is one of the easiest factory set ups to work with.

 

Because there's basically zero tunability with the factory head unit there shouldn't be an active cross over anywhere.

 

Passive-

Head unit> amplifier> cross over> speakers

 

Active-

Head unit> cross over> amplifier> speakers

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Yeah I cant wait until I've figured everything and installed it, its going to sound amazing to me. I also plan to out in a powered sub later too and splice in into one of the rear speaker's wire. Ok so I still have a question about the front speaker setup. Since I am potentially going to get rid of the factory amps in the front and put crossovers in place, will adding an aftermarket HU do anything to increase the watts going to the new aftermarket component set making them closer to their true potential quality since the amps are not there? How much wattsRMS do aftermarket HU on average put out because Im wandering if it will be the rated amount that the aftermarket component speakers seek?

 

Cham, we're kind of going in circles here, unfortunately. Regardless how you power the speakers, the amp's/headunit's RMS and max should be within the RMS range, and under the max spec'd by the speaker manufacturer. Same logic when pairing impedances; the amp needs to support the impedance of the speaker or the speaker configuration (i.e., series, parallel wiring, etc.). These specs are always listed for equipment. If you're not sure the RMS or impedance handling of something (in the case of the factory amp) for speakers, I suggest not using it. Most stereos range from about 15-25W RMS, and maybe 2-3 times that for max output. I doubt the factory amp is much different from those numbers.

 

The 6 wires go to the cross over/amp in the door. They do NOT go into the speaker. There's a plastic molded case that holds both the speaker and the cross over together as one nice package.

 

The small black boxes with wires hanging off of them in my picture are the cross overs, the two larger speakers are the fronts.

 

My aftermarket crossovers (Hertz) fit right in the factory enclosure. I had to do a lot of cutting to fit my Audison speakers but most all others fit fine. My aftermarket amp fits in the factory location and even mounts to the existing bracketry for it. Using the factory wiring, it handles all 4 channels.

 

Pulling the door panel off to actually see what's going on is not hard to do instead of guessing at it. It'll make a lot more sense once you do.

 

In all honesty, this is one of the easiest factory set ups to work with.

 

Because there's basically zero tunability with the factory head unit there shouldn't be an active cross over anywhere.

 

Passive-

Head unit> amplifier> cross over> speakers

 

Active-

Head unit> cross over> amplifier> speakers

 

Hopefully this is just metaphorical wires getting crossed, but this seems directed at me since I'm the only person talking about these specific items, though I've not stated or suggested anything contradictory to this to warrant the "NOT" or "instead of guessing" comments. Please let me know if I'm reading into that incorrectly.

 

I did not suggest 6 wires going to the speaker; that is what that FSM suggests...twice, actually. I paraphrased the front setup, and then also pasted exactly what the FSM says regarding the entire system. I speculated how it (the front amp) was connected to the speaker because the FSM does not indicate any wires. I see the leads in your pic; awesome—but it's irrelevant. What I implied was taking apart the front amp module to see what amp-like circuitry it has, if the tweeter and component are circuited in series or parallel, and if any resistors are embedded on the circuit that might filter frequencies before it goes to any speaker.

 

The thing that's screwing up this discussion is that no one knows the specs of the amps, and no one can validate a reason to use, bypass, or replace the amp. The reality: there is no wrong way...this topic is entirely subjective! It's getting generic answers because it is a generic topic.

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Not necessarily at you. It had been entwined the wiring diagrams suggest so which isn't the case. Honestly there's been quite a few times where the diagrams don't fully explain or are flat out wrong from what's really going on.

 

It had cross over style circuitry with resistors and coils embedded into a circuit board. I didn't look close enough to decide if the speakers were in series or parallel. To me it looked like an over complicated cross over... typical of something factory.

 

In another thread of Cham's I had mentioned that it's very possible the system is 2 ohm with very high sensitivity level speakers as that's how most manufacturers can get away with low power systems that sound decent. I had mentioned that due to this, replacing the speakers with 4 ohm or low sensitivity speakers may not sound good unless he went aftermarket for the amp.

 

And yes you're spot on about subjective. One persons "good" can be trash to another's.

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Kingman, you sound like you have actual experience with the factory BOSE setup, which is important here.

 

The FSM seems to show the front speakers being wired directly from the head unit and the amplifier in the back only supporting the rear speakers.

Something you said, seems to be saying that wasn't the actual case in your experience. Can you confirm that?

 

 

for Cham, you might be pretty happy with aftermarket front speakers (or components) with an aftermarket HU. Even if the front speakers don't go through the factory amp, you would have your fade setting to balance out the relative volumes. The HU would expect 4ohm speakers and do fine with it. Your rear speakers are 2ohm and the amplifier feeds that just fine obviously.

 

But what if your front speakers are powered by your rear amp too, as I suspect might be the case? Either way, you might be OK. Obviously if that's the case, you should be able to put in 2ohm speakers. But you can probably put in 4ohm speakers too....why do I say that? Well, because I am using my factory amp and have aftermarket speakers all the way around. Apparently the factory amp does 4ohms fine.... (as I said earlier in this thread, I don't have the BOSE option, but do have front components and amp...expect they are the same amp).

What happens when the factory amp sees 4ohm speakers, is it generates less power, so whatever it's RMS rating is at 2ohms, it's less with 4ohm speakers.

 

If that's a problem, I have probably avoided that problem just by virtue of never having turned my stereo up very high. :)

 

You also mentioned installing a sub at some point and simply tapping that signal off of the existing speaker wire going to a rear coaxial. That will dramatically change the ohms the amplifier gets on that one speaker wire and might not have a good outcome.

 

What I am considering doing myself is to replace the factory amp with an aftermarket 5-channel amp. Then my amp gives me a new dedicated channel to power a sub or subs.

Then I also won't have to worry about all of the unknowns I have regarding the factory amp. And I plan to find an amp, if at all possible, that I can install in the factory location.

 

 

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Ok thanks for everyones help. I've decided to install 2 ohm components in the front to match the rear speakers and to replace the factory amps in the front with the supplied crossovers. Ill also replace the HU and bypass the cargo amp powering the rear speakers so everything will be coming straight from the HU. I believe ill be happy with that and ill be able to add an aftermarket amp later on if I want. Oh and I also plan to add a powered sub to get that extra thump. I appreciate everyones input and hope I've started beneficial debate and information for everyone who's been apart of this thread. :aok:

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Mmmm hold on a second. If you run 2 ohm speakers you will need to find a deck capable of a 2 ohm load which I believe is basically impossible. Aftermarket decks are 4 ohm, you could very well damage the one you purchase by running the 2 ohm speakers directly from it...

 

Not guaranteeing a failure here but if you need to warranty a deck, they will know who happened.

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Ok thanks for everyones help. I've decided to install 2 ohm components in the front to match the rear speakers and to replace the factory amps in the front with the supplied crossovers. Ill also replace the HU and bypass the cargo amp powering the rear speakers so everything will be coming straight from the HU. I believe ill be happy with that and ill be able to add an aftermarket amp later on if I want. Oh and I also plan to add a powered sub to get that extra thump. I appreciate everyones input and hope I've started beneficial debate and information for everyone who's been apart of this thread. :aok:

 

I don't know about what the mismatched ohm load might do to a head unit so if you want to go this route, definitely check in to what Kingman has said.

 

If that is a show stopper for your plan, consider this alternative plan....

 

From where you are now, you can just add an aftermarket amp and be done....and the amp can be one with a 5th channel for a sub.

The amp will be able to handle mismatched ohm loads just fine and will provide different gain settings front and rear so you can adjust for volume differences you would see with mismatched ohm loads.

 

Here is an example: http://www.crutchfield.com/p_530PN5640D/Soundstream-Picasso-Nano-PN5-640D.html?tp=115

 

 

 

You know, I've forgotten what your real concern is. I remember you replaced your rear speakers and got no volume from them.

But are you wanting a new head unit? or new front speakers? Or was that all just snowball effect from the rear speakers?

 

Please answer this question:

Have you checked the wiring polarity at your rear speakers?

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The polarity is definitely correct no doubt about it. I also dont know what you mean jyeager about mismatching ohms because the ohm loads of each speakers are going to be the same. I already have JBL GX602s in the rear and I'm planning on putting in the matching components (JBL GX600C) in the front which are also 2 ohms. I don't want to have to go through all the trouble of installing an amp and having to run speaker wires to all the speakers. Also Kingman, why wouldn't an aftermarket deck like lets say the Kenwood DPX501BT work for 2 ohm speakers? I know the power output will be perfect for 2-70 RMS power speakers.

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I just checked the specs on that deck. It's rated power is at 4 ohms, not 2. However it doesn't say NOT to run 2 ohm speakers. In the aftermarket world, when dealing with power handling, the specs will be for 4, 2, or sometimes, 1 ohm loads so long as the unit is capable of it. Whatever a unit is rated at as far as ohm load is what it's designed to handle.

 

Running any audio component with an amplifier beyond what it's designed for generates excess heat that it can't efficiently dissipate. The lower the ohm load on an amp, the more power it generates which turns into heat. It's common law to not run a lower ohm load than what an amp is designed to handle. You can run a higher ohm load no problem.

 

I can't guarantee a failure like I said. However, I can guarantee it'll make more power but for how long? And to reiterate... if you return a deck with a burned out amplifier circuit due to heat they will know.

Edited by Kingman
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The polarity is definitely correct no doubt about it. I also dont know what you mean jyeager about mismatching ohms because the ohm loads of each speakers are going to be the same. I already have JBL GX602s in the rear and I'm planning on putting in the matching components (JBL GX600C) in the front which are also 2 ohms. I don't want to have to go through all the trouble of installing an amp and having to run speaker wires to all the speakers. Also Kingman, why wouldn't an aftermarket deck like lets say the Kenwood DPX501BT work for 2 ohm speakers? I know the power output will be perfect for 2-70 RMS power speakers.

sorry to confuse you. I was talking about the mismatched ohm loads you would have front vs. rear if you replaced your fronts with 4 ohm speakers...your new rear speakers are 2ohm as I understand it.

 

There are so many options, I guess it's hard to keep from getting confusing.

 

What do you want out of your stereo? Besides for your rear speakers to work as they should?

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  • 1 year later...

I am also seeking Pathy amp info on my 02 or whatever you guys suggest.

 

Turned on my truck to run errands, aftermarket stereo works, behaves like it works, but there's no audio. I return to Best Buy and BB spent over 3 hours testing the speakers, taking panels off, etc, He stated he even checked fuses first. Last thing he did was pull the stereo out and wire in test speakers. There's audio from the test speakers. BB guy thinks it's the amps, but he says only Nissan will be able to say which one or all of them.

 

BB is quoting me over $800 to replace everything, because he says with the way Bose is, they can't bypass, they can only replace everything, including wiring, amp, etc.

 

If you think it's the amps? Do they even sell replacement amps that aren't 15 years old (I don't want to spend money and then it die in a few months due to age).

 

Is Best Buy full of bull poop? IS there an easier and hopefully cheaper solution? I don't want to do any wiring myself, I don't have the guts or brains for that. I can do ball joints, swap out starters, but wiring? No thanks!

 

Thank you so much in advance, and I shall apologise in advance if it takes me a few days to get back to you.

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