I suppose you could try using a laptop over AUX or something in order to play a increasingly lower/higher frequency pure tone (with the output muted so you don't torture yourself) until the measured output is distorted in order to determine the lowest and highest frequency that the HU can properly output and then you'd know the bandwidth before the amp is taken into consideration. Though there would be the concern that one of the extents might actually be limited by your playback device and not the HU itself.

If you mean for the amps power, it's just standard 12V, but if you mean the voltage of the signal lines, it of course depends on the signal in question and what the volume is set to. I don't recall what the peak voltage was at maximum volume. I want to say 2V but im really not sure.

Thanks for pointing that out. Not sure how I managed that, but it should be fixed now.

@@oblivioncth no worries; and thanks for the support, despite it's age.

Haha. It's because I play on a 21:9 monitor. It's not deal for recording gameplay since most people have 16:9 monitors so it gets letter boxed like you noticed when watching it on those, but it's sure great for playing!

@@oblivioncth well, as long as you're enjoying yourself.

Wow that's wacky. Unfortunately I don't have access to a newer one with that "feature" so I really can't say, outside of replacing the whole amp with a custom one just for that issue, lol.

Damn. It's been a bit since this run so I can't be sure, but honestly, I may have not even noticed that happened.

I'm assuming you're talking about the front door woofers. They are pretty large, a little under 9" so they're definitely only suited for lower tones. All of the division of frequency is handled by the BOSE amp. The signal coming from the Headunit/TAU is full range and entirely unaltered, so the BOSE amp more-or-less doubles as an active (or perhaps passive, I haven't looked at the internals) crossover. If you tap into the front door speakers directly you'd of course be limited to whatever frequency band they are fed by the amp. The cutoff might be a bit high for a full size sub, since those they aren't quite big enough to be a true sub, but I'm not sure since I've never monitored the output going to those speakers on the original system directly. If you want 100% control on what feeds your mono amp you'll have to tap at the headunit.

Thank you! I can’t believe you replied haha. I’m super new to this, I didn’t know anything about car audio this morning, so bear with me, but I like messing with guitar electronics and want take on a bigger project. The sub is a “12 150watt. The amp is a small 2 channel (kicker DXA125.2) with 125watts out (bridged). Im just wondering how to tap into the head unit channels. I’ve seen some harnesses that adds another five channels that plugs into the head unit but I called a local shop and they said something like that wouldn’t work and that my best bet would be to tap into the wires after the amp and mount the amp in the trunk. I’m not sure if I explained it well enough to them though. What would you suggest?

@@oblivioncth Additionally, the amp has a signal input switch for low and hi input so I’m assuming I wouldn’t need to convert to low, so would I just splice a RCA cable directly into the corresponding wire pair? Or do they have harnesses that run RCA out? Please correct me if anything I said was incorrect. Thx again!

@@ethancontreras3538 Doing the investigative work on this car was my first real foray into car audio beyond the little bit I already knew, so I actually can't offer a ton of advice outside of what I did. In my case I replaced the entire stock amp so I avoided the complications related to splicing into the existing equipment while keeping it running as is. Tapping off the headunit lo-level signals (which is generally best) for a mono-amp config requires splitting one of the 4-channel outputs form the HU into 2 (one going to the BOSE amp as it does originally, and the other to your new amp). Technically, the best way to do this is a "splitter", which is generally just a box that does some extra massaging of the signal to assure that both outputs of the split are the same as the single output you start with; however, splitters can often get complicated and are often have many more features for other circumstances that are outside the scope of what you're trying to do that I'm not very familiar with. That being said, you can just basically create a "Y" cable by splicing into the two wires that compose any of the 4 output channels from the head unit and just connecting some extras wires to those to create the inputs for your amp (basically just cutting into the existing cable and siphoning off it). Most half-decent audio equipment for years now tends to follow a low output impedance, high input impedance paradigm which allows to you split a lo-level signal like this many times before notable loss occurs; however, technically speaking the BOSE HU doesn't have to do this since it wasnt intended for aftermarket connections and normally is a closed system. So while I cannot guarantee that simply splicing off the existing cable will work without any significant change to the signals, it should given how standard said paradigm is. I think thats why shops are hesitate to have people do it, because they can't guarantee how the stock HU of any random car is designed and how its signals are implemented. As long as you're OK splicing in and simply taping the wire back up if you run into issues, I say go for it if you want to be absolutely perfect. At the same time though, the signal needed to drive a sub doesn't need to be 100% pristine since its only for ~120Hz and below, so tiny imperfections will go totally unnoticed. Therefore, if you want to play it absolutely safe, taping into the front or rear door speakers post-bose amp and using the hi-level inputs on your amps would probably sound perfectly fine. I think either way should really do the trick, and would only push for going off the headunit instead of post-BOSE amp if you were adding/changing more than just a sub.

@@ethancontreras3538 If you do tap the high-level signals post-BOSE amp the high-level inputs on your kicker should work just fine. As for the connections, basically no custom harnesses exist for the modern Mazdas. There is the harness included with the PAC AOEM-MAZ2 for much older ones that I remember seeing someone said they used successfully somewhere, but there were some caveats and tradeoffs with it so I probably wouldnt bother.

I'm not 100% sure, but it's my understanding that everything from the BOSE systems is 2 ohm

I can't be 100% sure since I don't have one, but I believe so. I found the audio system diagrams for the 2018 here (warning the sites kind of crappy): cardiagn.com/2018-mazda-6-2-0l-2-5l-ewd-audio-system/ I would imagine it should be largely the same as the 2019 since no major entertainment system changes were made between those years. From looking at it, I can confirm that the line-level audio channel connections are identical and that the colors for those wires haven't changed either (0920-515A in my guide, 0920-322A on the 2018 manual). When it comes to all of the other connections to the BOSE amp, I only gave them a cursory glance but they seem to all be the same as well; however, do note that a lot of the wire coloring changed for those connections.

Yea this is more of just an interesting technical tidbit. Being really efficient with items, like invulnerability as you mentioned, is arguably more important. If you want to try and kill a boss as fast as possible though, this is the best way I've found so far (though to be fair I haven't looked into other methods that much): kzbin.info/www/bejne/omWbZKRoepaZgc0

@@oblivioncth holy crap that's fast! I was just excited cus this was literally my first time playing since being a toddler and barely understanding what I was seeing. The first two realms really set me back. But that invulnerability trick made me laugh because it reminded me of a trick just like it in a game called RuneScape. But yeah I already beat the game on hard. Took me 18 hours apparently but that's because I fell asleep on a level a couple of times.

@@wesleysackett3407 yea its pretty crazy how much content the game has for what was essentially an arcade game. A childhood classic of mine as well

@@oblivioncth hopefully with emulation getting better we can maybe hopefully start to see some online play with this game using net play like I have seen for other games on emulators with split screen functions

@@wesleysackett3407 I haven't tested it with this game specifically, but I'm pretty sure that Dolphin netplay would work with this game. There's also the fan remake that's in the works

There are 4 input channels, that doesn't mean there are 4 output channels, but yes there is no dedicated original signal for the center. I believe the BOSE amp does something like summing the front left and right input channels and then band-passing them to the typical range centers are used for to create the center output. Otherwise, it's a 3 way setup in the front and 2 way in the rear. Each front door woofer, and front dash tweeter + twittler are associated with an input channel, being split actively or passively by the BOSE amp, while the same thing is true for the rear channels and each rear door woofer and rear deck twiddler as you said. If it was something designed to watch movies in then it would be nice to have a real 5th channel, but the four channels are just duplicated stereo anyway that exist solely for the fade function, so of course the center is going to be simulated. I was kind of interested in keeping it by doing something similar when I replaced everything, but it would have been addition work, complexity, and cost for something that was really unnecessary given the better replacement equipment of everything else.

@@oblivioncth so there are 4 channel input but 8 output? If the speaker are already wired separately up to the bose amp it would simplify the install since I won't have to wire from the amp to the speakers. I'm still debating on wether I run it as 8 channel(keeping the center one as is) or only 4(or 5)(in that case using the rear deck as sub, and component system in the front)

@@C0LiSii0N Yea the input is four channel, and at the output there is a separate pair of connections at the amp for all 11 speakers (sort of, a few speakers share a few). I really doubt they are doing active crossovers and its actually 11 channels as that would be nuts. If I had to guess each input channel is split to each speaker group using passive crossovers internally and then the front left and front right inputs are combined and band-passed to make a simulated 5th output channel for the center, making it more-or-less a 5-channel output. It's just that the passive crossovers are also inside so at the actually output terminals of the amp it's just the connections that go directly to the speakers. For the front, the tweeter and twiddler of each pair share a connection. For the rear, annoyingly the rear deck twiddlers are wired together. You'll see this if you look at the bottom of the forum post in the description, there's a image I threw together that shows all of the connections and makes it pretty obvious. I personally went with a direct 3-way replacement for the fronts, and then put full range monitors in the rear doors, and then just kept the stock twiddlers as a form of basic rear fill. Center was simply not used. Other than the water issues the 2014-2017s are known for causing me a bit of a headache, I've been pretty happy with it. There are definitely many ways you can go.

Here is a direct link to the image in question: i.imgur.com/pApxn2e.png

@@oblivioncth Thanks a lot! I missed that one on the forum lol Hey, would you happend to know the spec(Aprox.) of the bose amp(output power for example)? Like, if the bose amp output enough current, I won't buy a new one for nothing haha

It's a KENSTYLE wheel I imported from Japan, I think through Japanparts.com (sorry I don't have the order email anymore); however, they don't seem to have the one I got anymore. I think it's the MB01 they have here www.nengun.com/kenstyle/steering-wheel-mazda-atenza-sedan-wagon-gj I dont remember exactly have to convert the Japanese car model to what we have, as they released them at different times so the ranges don't line up exact. I know the 2016 is a GJ, but forget what the sub numbers mean. In Japan some GJs are from lager years so the exact one matters. The site I bought mine on filtered by VIN and that's how I knew I got the right one. Definitely requires some research to make sure you don't get screwed, but that's definitely the manufacturer and general category for the wheel.

Generally in most cases the frequencies that low are going to be more or less the same, but for the small cases where it isn't, and if you want to be complete as possible then yea you'd want a mono amp that has 2 input channels, then draw from the FL and FR or RL and RR

Thanks for the quick response! And for sharing all the helpful info. : )

It can basically be any of the channels you want. Since you are mentioning two pairs of wires I'm assuming that the sub-amp you plan on using has a two channel (left and right) input. In this case just use the left/right set from either the front or back. So either: Left Input - (FL) Black/White Right Input - (FR) Red/Green or (the set you mentioned) Left Input - (RL) Pink/Light Green Right Input (RR) Grey/Blue One thing to keep in mind is that the choice does matter if you use your fader, as the fade is controlled by the headunit, so your sub volume will be lowered if you ever fade the channel(s) its sourced from. This can either be desirable or not. For example, if you're likely to generally fade out the rear and never want your sub faded, source the sub-amp from the front L/R pair, or if you do want the sub to fade with the rest of the rear, then source the sub-amp from the rear L/R. If you don't ever use your fader then obviously this isn't an issue.

More or less yes. With the LOC you'd be only using a portion of the signal that's going to one of the speakers, having already been somewhat frequency gated by the BOSE amp. The rear door speakers are probably best for this since they're near full range, but if you want the ideal its best to just tap any of the 4 input channels I talk about in the video/post directly and feed that to a mono-block amp for your sub. The only thing worse about it than doing the speakers is that if you're putting your sub in your trunk like most do, obviously the front passenger seat area is a more annoying cable run than a rear door speaker, but its otherwise a simpler (no LOC required, just the amp and sub) and cleaner setup overall.

See the 4th to last picture in the forum post linked in the description. It's the one with the pinouts of the connectors at the BOSE amp. Connector 0920-515A, which is the widest one, is what you want. 8 of the wires/pins are for the 4-channel headunit output, ignore the other two that are for the audiopilot mic. You should be able to splice anywhere along that cable as long as you grab the 8 correct wires and know which is which.

With a 2016 6 you definitely have the TAU built into the headunit so don't worry about that. If you want to bypass the stock amp you don't need a LOC at all, which is why I delved into trying to figure things out with the audio system on this car as that's what I wanted to avoid. Sorry if it was confusing exactly what was going into/coming out of what since everything I showed was at the plugs for the BOSE amp, but cable 0920-515A goes between the headunit and BOSE amp and it carries the 4-channel output from the headunit that you can feed directly into your own amp if you splice into it at the end that was going into the BOSE amp and terminate the 8 wires you need with RCA ends (or whatever your amp accepts). You just have to create the ends with each pair for each channel (i.e. black and white is the front left channel) as described in the video/forum post and those can go straight into you amp. Just leave everything else disconnected and make the power & speaker connections to your amp and you're basically done, other than running cables obviously. It ends up being: Headunit -> End 1 (that you don't need to access) of 0920-515A -> End 2 (at BOSE amp under passenger seat) of 0920-515A -> Your Amp's audio inputs I wouldn't recommend reusing the factory wiring for the speakers, but if you're not going to play your system very loud you technically can. If you do this you do not need a LOC for that either, you would just need to splice into 0920-515B & 0920-515C for the wire's going to the speakers (the last diagram in the forum post is helpful for this) and connect those to your amp's audio outputs. Do note though that the factory wiring has the rear deck "Twiddlers" (mid-range) speakers tied together (essentially making them mono) and you can't separate them unless you do your own runs, and you may have to adjust the balance to not have them sound overpowered since you'll have to connect them to both the rear right and left outputs of your amp.

@@oblivioncth Thanks for the reply. So I can just take the 0920-515A cables and splice them into RCAs, that's cool. 515A is what comes from the headunit, and 515B and 515C are the outputs to the speakers. Did i get that right? The reason I wanted to reuse the factory wiring is that I wouldn't have to run cables back from the amp into each speaker. It would've been faster to just go into 0920-515B and 0920-515C rather than routing cables through the doors. Well, if I'll replace the speakers I may as well turn up the volume and enjoy them. I've seen different variants, and they were between 60 and 100W RMS. Would you say component or coaxial in front?

@@11ryn Yes you have that correct with the cables. I can definitely understand wanting the convivence of using the factory wiring, and ultimately I view it as a little less of a sin than most enthusiasts probably do, but the main reason it's a problem and that I mention audio volume is for safety. The factory wiring on 99% of vehicles is usually very small gauge and usually just barely thick enough for the generally low (relative to aftermarket) wattage rating of the factory speakers. For example, the fuse going to the stock BOSE amp is 25A, which means that at the 12.5V the amp runs at it will blow if your power usage is above a measly 312.5W. Obviously there's a big difference between peak power draw and RMS, each speaker size will vary in its draw, and the power drawn from each channel doesn't cause a 1-to-1 change in the amount drawn from the amp input, etc. but just realize that if you put even just a 700W amp in a crank the system up quite a bit that you can draw up to nearly twice as much current through those lines as was ever intended, which is obviously a fire and equipment damage risk. Loudness is subjective, and you can still probably get fairly loud without issue, but I just mention this to be clear since you will technically be in a situation where you can have major problems depending on your usage. When it comes to setup, there's obviously a lot of options with many right answers and lots of subjectivity involved, with restrictions based on budget. I don't remember the power cap of my units but I personally used a 3-way component setup in the front, and a pair of coaxials in the rear doors, while leaving the rear deck speakers stock.

Haha lol didn't see you checked this, thanks. I tend to be very much "if you're going to do it, do it right", so I pass on a lot of stuff but the things I do go for I often go pretty hard with (though sometimes to my detriment ><), hence wanting to try the Gwyn challenge as my first dark souls challenge run XD. BTW I am going to get to work on that video soon, I put it off cause my older PC my struggling to deal with the 4K footage but I just managed to score a 3080 (and got a 5950X back in april) after trying since January, so once thats together the editing process will be way less frustrating/restrictive.

I haven't been in a CX5 (let alone 2020) and there aren't wiring diagrams for it in particular, so I can't be sure of how its different. I did do a quick drawing of the 2018 CX5 wiring that would probably apply to the 2020 (they only change them ever so often but its never 100% clear what range of years that a particular workshop manual applies to), but as for the physical location of everything I'm not sure. You want to start by locating the BOSE amp, which is likely under the passenger seat or behind the glove box as you noted. Once you find that, reference this drawing to know what connections you want to use: i.imgur.com/wNoHrGI.png You can splice into the cabling at any point in the line (before it gets to another device obviously) so at that point its up to you if you want to follow the cables back up a bit instead of splicing right at the amp.

The stock headunit is generally best unless you don't mind losing all of the integrated functionality such as oil warnings, door lock settings, etc., but I'd definitely suggest making use of your own amp using the information in the video otherwise. However, just doing a sub is something a lot of people do. For that if you're going to tap pre-Bose amp as described in the video you'll need at least a 1-channel amp, which would then possibly be useless if you decide to do more later. If you think its highly likely you'll only ever have the aftermarket sub, splicing into the rear door speaker wiring and taping into that with a low-pass filter (or sub with built in crossover) is often good enough. For anything more than a sub though, the line-level pre-Bose amp signals are the way to go.

Thanks. Interesting, I guess they do it a bit differently in the 2s (I don't think they even offer those in my region). My vehicle doesn't have a separate TAU and has no rolloff before the BOSE amp, and I didn't think the earlier 6s/3s that have the separate unit did either but its possible they do. I can only go off what I heard from one other owner and the fact that I believe the amp model number between the 2014/2015 and 2016+ amps for the 6 are the same, but its possible there's a software or regional difference.

@@oblivioncth thanks again man for your reply.. i kinda miss on your video so i just want to make sure, the signal from the head unit that you tested is it low level or high level? i kinda see 50mV or something on your oscilloscope..

Unfortunately it can be a bit tricky. Many amps can handle them fine depending on their internal circuitry even if they don't explicitly mention working with them, it mainly depends on if the ground of the channels inputs are isolated and can handle a moving reference without issue or are tied to the ground of the rest of the amp/DSP. If it doesn't work directly you will need to put a differential-to-single-ended converter between the headunit and your equipment. Sadly for whatever reason that doesn't seem to be available as a commercial device, but it is a really simple circuit that you can find many references to online. Since it can be different on a case-by-case basis, honestly I'd reach out to the manufacturer of your amp/DSP (or that you plan to buy) as they will likely be able to let you know the best way to proceed. Just let them know you have access to 4-channel differential line-level audio. The issue of differential vs single ended isn't specific to this car, its a general audio concern so I'd imagine they'd be able to offer some advice. Then you can use the information in the video for everything else. Other than a possible converter needed the connections are still the same.

@@oblivioncth Oh, you're still active on this account. I have an OLD Audiobahn A4002V so I suspect compatibility issues. As much as I hate to do it, I think I'm just gonna go the LOC route since it's only to add a subwoofer.

@@Apizur Ah. Yea for something older it may be harder to get information and if you're just adding a sub a LOC isn't too bad. Sorry, did you try to contact me on Mazda6Club or something? Its a long story but I've been unable to be that active anywhere due to personal issues.

@@oblivioncth I saw your post originally on the forum. I tried to trace you upstream a bit... I even looked on Steam XD, just because I couldn't find a good resource on my question. I haven't done install in a while... Did you grab accessory from the ignition cluster or was your amp voltage sensing?

@@Apizur Ah lol. The is ACC at the BOSE amp connections actually but my personal amp is voltage sensing.

I can't be 100% sure since I don't have access to a 3rd gen CX-5, but I was able to find the wiring diagrams for it online. The plugs are all the same shapes and sizes and the wiring colors are mostly the same. The most differences are the colors on the largest and second largest cable that hold connections to the stock speakers, car power, ground, etc. The 16-pin (6 of which are not present) connector with the 4-channel low-level output (that is most likely what you're interested in) and Audio-pilot mic input, 0920-515A in the 6, is actually exactly the same other than that the one wire for the Audiopilot mic that is black/red in the 6 is yellow in the CX-5. As the video states, these wires are annoyingly unlabeled, but I really doubt they would move around which pin was which channel yet keep the colors all the same so I'm 95% sure the wiring for the smaller 16-pin connector is exactly the same. Obviously if you pull out the connector and the 6 (3 top, 3 bottom) terminals on the right of it are actually in use, or the wire colors are drastically different, then stop because then it may not be the same. The diagrams I found are for the 2018 but I don't think they've really changed anything since the 2014. If you want to tap something from the other 2 connectors (i.e. 12V ACC/Turn-on signal power, stock speakers, stock ground, etc.), let me know and I'll look over those connecters as well, because their connections are at least labeled in the diagrams.

@@oblivioncth Appreciated your feedback and Yes if you don't mind specifying the rest (as i think i will need them) like Remote Turn-On and Constant 12v.

@@rodiellezcano2024 Here. It isn't as elegant as the one's I did for the 6, but I filled in the colors and labels so it should suffice. Make sure the wire colors match what is in your car at the BOSE amp as while the site I got the diagrams copy off of said it was for the 2016-2019 CX-5, the diagram itself is labeled for the 2018 CX-5. This is normal with Mazda, as for example the diagams I had to use for the 2016 6 were labeled as being for the 2014, its just a little odd that in this case the diagrams are dated newer than the vehicle instead of older. They almost always change colors when the functions change so if all the wire coloring is the same for you then that site was correct and the 2018 diagrams apply to the 2016 as well. One oddity is that on the CX-5 there is a signal for the I-Stop function going to the amp. I can only imagine it is to limit the output power of the amp while the engine is off so that your battery doesn't drain too much, but I can't be sure. I doubt it will actually affect the I-Stop system itself, but you may want to test drive with the amp unplugged just to be safe. i.imgur.com/wNoHrGI.png

I can find the exact model numbers if needed, but the basic overview is a JL VX1000/5i Amp, 3-way component HAT Unitiy sets for the front left and right, HAT Imagine Convertibles for the rear left and right, and a JLW3v3 12W subwoofer in a sealed enclosure.

The original thread I used as a starting point might be a good reference as that user just wanted to add a sub as well: www.mazda6club.com/threads/2016-headunit-location.386602/. You would need to get a mono amp, feed its input from any one of the four low/line-level headunit output channels I show in this video (or companion form post in the description), OTHER than the front left (since that gets lowered for voice command input) and then just feed its output straight to the spare tire sub. There is no way to connect it directly to the BOSE amp on a 3/6 because the subwoofer output line that is used on the CX-9's version of the BOSE amp is already taken by one of the front door woofers. You could tap directly off one of those and skip the mono amplifier but it would most likely make the front door woofer you choose to tap from sound quieter and you would lose the ability to control the subwoofers volume separately from everything else.

@ oblivioncth I've been the Mazda6Club and on your forum. I have a question that I wanted to get a quick answer to. I'm going to be attempting this tomorrow. I'm very new to this as well but I have some DIY knowledge. i.imgur.com/Lyuef1R.png The Rear L & R from your picture here, can I do a Y split, have 1 end go to the sub and the other noraml to the Rear L & R Bose speakers? Thank you :)

I added an underwear subwoofer and I couldn't hear it because my Bose systems bass was louder

Yes, that is exactly what I'd do. However, do not use black and white (the front left channel), because that is the channel used for AA/Carplay/Mazda Nav notification which would mean everytime a notification was played your subs volume would lower, just like the Front Left speakers due when music is playing, and the notification would also be played through your sub (obviously only the low frequencies though). Use any of the other 3 channels and you're fine

@@oblivioncth perfect, any pair you would recommend besides the black and white more than another? On another note I stopped half way through my install and noticed the windows wouldn't go up automatically with one touch. Any ideas? Lol the only thing unhooked is the amp. Maybe I blew a fuse. But they still go up if I hold them.

@@DaneISGr8 For whatever reason whenever you disconnect the battery or it dies, the automatic window feature is disabled until it is reset. If I remember correctly, you have to low the window all the way, then immediately raise it all the way and keep holding up even after it closes for 3 seconds. Then the auto function should work again. As for which channel to use it really doesn't matter. Choose any of the other 3 that your the least likely to ever use the fade feature with since fading that channel would lower your subs volume too

@@oblivioncth you the man 😎

I'd be fine giving you my email but don't exactly want it posted publically; however, youtube has really demolished messaging on KZbin so I'm not sure how I'd get it to you. I have an account on the forum linked in the description if you didn't mind making an account there you could PM me on that platform.

@@oblivioncth that's what I'll end up doing

Actually I don't care if I share my Facebook and email. Facebook is Kyle Gainesville and email is [email protected] I'll just delete after I get in touch with you.

@@eldergoose4075 hey might want to delete now haha 4mos later, also, how did it go!? :-)

@@zane812 actually haven't gotten around to it yet. My box was finally shipped to me this past week so soon!

I'm quite satisfied with the full system replacement I have... but it also cost nearly 4000 dollars. You can definitely achieve something almost as good, especially if you do all the work yourself for half as much. The rough thing is that with how much of the rear door speakers you hear and the fact that the speakers up front are 3-way component, there isnt a very effective way to only replace a portion of the system other than just adding a subwoofer, or maybe replacing the front woofers. Because have mismatched components in a 3-way setup can be really hard to get to sound any good, especially if you're replacing the high end. Obviously I'd start with the amp, and maybe you'd be satisfied with just doing the front 3-ways (maybe you manage to just replace the mid and high drivers and get it to sound half decent through amp tuning), though like I said I was quite surprised how much of the sound in the front is dictated by the rear door full range speakers because of how close the front seats are to them. I definitely would go a bit less name brand next time around to save some money, but unfortunately upgrading the audio in this car is expensive because of how it is set up. You cant recoupe a ton off your BOSE parts though since everyone knowa they're junk, even though they sell for a ton new. I was able to get about $400 after selling everything other than the rear deck speakers.