Mazda 3 2007 bose replacement issues

[Jkmorris]

Hello,

So just a bunch of random question. I have replaced the door speakers with all 6.5 alpines (comp front, rear Coax), added a sub, and replaced the stock headunit with an alpine receiver. Everything was goung well, but I kept hearing how I needed to bypass the bose amp after replacinga the speakers due to impedance and Bose hating everything not bose. So I did the speakers, and I paid best buy to bypass the amp. All they did was chop up the bose harness and splice the existing connections to new wires from the head. As far as I know the bose amp is still powered...and my stereo syustem sounds way worse. Not terrible, just....not right?? I thought my speakers would be louder as the headunit power @ 4-ohms vs the 2-ohm on the bose??? now I have to crank the headunit to 20-25 whereas bose amped was pretty insane at like 14 volume. This seems backwards? Any ideas?

If it helps...the audio controls/eq on my headunit and fade etc all work. the only thing i notice is the volume jumping if i adjust the basic eq. No HP filter applied, LP set on amp @ 60ish, flat eq on headunit. Always play my iphone through usb.

Thanks in advance. Just frustrated....

Complete setup: Alpine 145BT, 4xAlpine 6.5 (F:SPS-610c,R:SPE-6000), alpine 250 mono amp 150RMS @ 4-ohms into 10" bassline SVC 4 Ohms.

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[Jeffdachef 5,000+ posts]

Hello,So just a bunch of random question. I have replaced the door speakers with all 6.5 alpines (comp front, rear Coax), added a sub, and replaced the stock headunit with an alpine receiver. Everything was goung well, but I kept hearing how I needed to bypass the bose amp after replacinga the speakers due to impedance and Bose hating everything not bose. So I did the speakers, and I paid best buy to bypass the amp. All they did was chop up the bose harness and splice the existing connections to new wires from the head. As far as I know the bose amp is still powered...and my stereo syustem sounds way worse. Not terrible, just....not right?? I thought my speakers would be louder as the headunit power @ 4-ohms vs the 2-ohm on the bose??? now I have to crank the headunit to 20-25 whereas bose amped was pretty insane at like 14 volume. This seems backwards? Any ideas?

If it helps...the audio controls/eq on my headunit and fade etc all work. the only thing i notice is the volume jumping if i adjust the basic eq. No HP filter applied, LP set on amp @ 60ish, flat eq on headunit. Always play my iphone through usb.

Thanks in advance. Just frustrated....

Complete setup: Alpine 145BT, 4xAlpine 6.5 (F:SPS-610c,R:SPE-6000), alpine 250 mono amp 150RMS @ 4-ohms into 10" bassline SVC 4 Ohms.

you fked up and the info you found regarding that is beyond stupid lmao... ohms is the speaker load not what the amp puts out and the lower the ohm load, the more power will be drawn from the amp. for example, your amp is rated 50 watts x 4 at 4 ohm load, at a 2 ohm load you'll see 75 watts. You are at 4 ohms with the alpines which means you already use less of the bose amp because of the higher ohm load so the amp is already putting out way less power than with the stock bose speaker, it only feels louder because the new speakers are more efficient with the power meaning they get louder with less power. The factory amp provides way more power than a head unit's internal amp, head unit amps are garbage thats why you always pair speakers with an amp. Never allow anyone to chop up any kind of harness or use a proper adapter harness. The factory amp also has built in EQ curves to shape the sound.

Only way to fix this is to install an after market amp and do a proper system tune afterwards. Dont go to best buy, that sounds like a hack job install.

Bet you really didnt see that big of a difference after the speaker swap either, most likely lost some door speaker bass too right?

 

[Jkmorris]

Lol man everybody fks up the first few times. So the doors to headunit are parallel or series? Either way, the load on the bose amp would be double going from 2 ohms to 4 on each speaker?? That’s more resistance so less power? Assuming the bose is about 20ish watts with the stock bose speakers, I don’t see why leaving my new ones hooked up is a better idea than going to the headunit with matched impedance at higher rms wattage? I thought the rule was higher impedance speakers to lower amp was fine but less power, but never the other way around.

I can put a two channel or that power pack thing in. Would you suggest wiring bridged to the components and run the rears on the headunit? Advice for tuning? Yea dude tell me about it. The guy who did my headunit did a great job and was really cool about it. This time the installer was just ******. Oh well. I’ll get my money back and probably some free stuff.,

Suggestions for better speakers and tuning the sub? It’s cool to mess with this stuff and get my hands dirty. Just a lot I’ve yet to experience haha. I thought about a five channel since the speakers are already under the driver’s seat next to the bose amp. It’d be easy to do that and just redo the sub wiring.

So let’s say I go 50x4 + 300 or so to the sub. I’ve got eight gauge power and ground currently with the mono block. I think that’s plenty for 500 rms, but most of the amps recommend four gauge.

Thanks for the help dude.

 

[Jeffdachef 5,000+ posts]

Lol man everybody fks up the first few times. So the doors to headunit are parallel or series? Either way, the load on the bose amp would be double going from 2 ohms to 4 on each speaker?? That’s more resistance so less power? Assuming the bose is about 20ish watts with the stock bose speakers, I don’t see why leaving my new ones hooked up is a better idea than going to the headunit with matched impedance at higher rms wattage? I thought the rule was higher impedance speakers to lower amp was fine but less power, but never the other way around.
I can put a two channel or that power pack thing in. Would you suggest wiring bridged to the components and run the rears on the headunit? Advice for tuning? Yea dude tell me about it. The guy who did my headunit did a great job and was really cool about it. This time the installer was just ******. Oh well. I’ll get my money back and probably some free stuff.,

Suggestions for better speakers and tuning the sub? It’s cool to mess with this stuff and get my hands dirty. Just a lot I’ve yet to experience haha. I thought about a five channel since the speakers are already under the driver’s seat next to the bose amp. It’d be easy to do that and just redo the sub wiring.

So let’s say I go 50x4 + 300 or so to the sub. I’ve got eight gauge power and ground currently with the mono block. I think that’s plenty for 500 rms, but most of the amps recommend four gauge.

Thanks for the help dude.

Pretty sure the stock bose amp is more power than 20 watts at 2 ohms. Also head unit power is never what they advertise, its more like 10-12 watts a channel for aftermarket and 3-5 watts for stock Even though they dare to label 22 watts rms for their head units. You are talking about a dedicated amplifier board vs a small little amplifier chip on the head unit. What do you think makes more power?

The 5 channel amp idea is good. You'll still have to run exttra RCAs and speaker wire to the back of the head unit.