Yes. But it is not normal for a bottom end midrange and tweeter to get the entire signal by itself. The tweeter's sole method of dealing with the 4000hz and under frequencies is a capacitor the size of a pea. Further, the Bose mid has no ability to reproduce high frequencies and extreme lows. A side by side comparison with the stock system and the modified was dramatic at higher volumes to my ears and expectations.

Fair enough. I admitted off the start I'm not into bass.

What? You start off as admitting that improvements are subjective. Yet you then state that most people make changes that aren't ideal and they actually degrade the system. How can it be less than ideal or degraded if it meets with their audio needs? How can anyone report all of the flaws when they're subjective to begin with? Probably with a different thread!

Bottom line is we all here music differently and any system should be designed for the individual, nothing else.

 

For anyone that's reading the posts between dillyyo and myself, here are some quick explanations of terms we're tossing around:

Standard High Pass Filter (Used on Bose tweeter)
High Pass filters allow high frequencies above a selected crossover frequency to pass, filtering out all frequencies below it. In a first order (6dB per octave) filter, this consist of a capacitor in series with a loudspeaker. Just above the crossover frequency, the capacitor begins to add resistance to the circuit. At the crossover frequency enough resistance has been added to equal the resistance of the loudspeaker and reduce the power by 3 dB or 50 %. One octave below the crossover frequency, power has been reduced by 6 dB or 75%. Each octave lower reduces the power by an additional 6 dB. The size of the capacitor will be determined by the impedance of the loudspeaker(s) and the desired crossover point. The smaller the size or value of a capacitor (microfarads, µfd or mfd) is, not physical size, the higher the high pass frequency will be.

Standard Bandpass Filter
Band Pass filters allow a range of frequencies to pass above a selected crossover frequency and below another selected crossover frequency, filtering out all frequencies outside this band. In a first order (6dB per octave) filter, this consist of a low pass filter (coil) and a high pass filter (capacitor) in series with a loudspeaker.

Non Standard
In some cases it is necessary to increase the cut off rate or slope to higher than 6 dB per octave (first order). With tweeters this is especially important. Low frequencies will damage tweeters. Using a second order (12 dB per octave) or third order (18 dB per octave) high pass filter will reduce the lower frequencies at a steeper rate than a first order filter. A tweeter with a third order high pass filter with a crossover frequency of 5000 Hz driven by the 100 watt amplifier used in the power chart above, will recieve about 1.6 watts at 2500 Hz versus 25 watts with a first order filter at full output. The use of higher order filters allows loudspeakers to be played at the limits of their efficiency. Higher order filters can also be beneficial in compensating for natural peaks within the listening enviroment (vehicle). Different orders may be used in your design. You can have a first order low pass filter for a woofer, a third order narrow band pass filter for a mid-bass, a second order band pass filter for a midrange, and a third order high pass filter for a tweeter. When building passive crossovers, be sure to calculate for the correct impedance of each loudspeaker. Impedance is relative to frequency.

The JL crossover is a 12db unit as opposed to the first order of the stock tweeter and a first order coil in the amplifier for the stock midrange.

 

Well, like the front Bose woofer, the replacement of the rear 6x9's is a fail. There is so little power going to these as is that any quality replacement doesn't sound any better. Couple that with the complete lack of high frequencies and this is just not worth doing without external amplification. I'm going to leave the JL 6x9's in there for now as they're not hurting anything and I may amplify in the future.

So, to complete this thread on just rear speaker swapping, don't do it in my opinion. It would only be beneficial if you to go all out and upgrade the speakers with an amp as there's not a tremendous gain in just the replacement of the stock speakers.

 

Yes. But it is not normal for a bottom end midrange and tweeter to get the entire signal by itself. The tweeter's sole method of dealing with the 4000hz and under frequencies is a capacitor the size of a pea. Further, the Bose mid has no ability to reproduce high frequencies and extreme lows. A side by side comparison with the stock system and the modified was dramatic at higher volumes to my ears and expectations.


I will assume you meant 4000hz and above as those tweeters don't play those lower octaves. Simple capacitors are crude, simple yet reasonably effective in attentuating certain frequencies. I don't know what you mean by extreme lows or high. I see no reason why that speaker couldn't produce octaves that are intended for midrange. If you mean for example <100 hz and >9000 hz then I would say you are probably correct, but who would use it for that type of application? I'm sure your setup was drastically different, but I am sure still lacking in the aspects I had aforementioned with the stock system....lack of accurate mid bass and sub bass reproduction.






Fair enough. I admitted off the start I'm not into bass.


My comment did not imply whether someone is into bass or not. If you refute accurate mid bass and sub bass reproduction, you are admitting you are not into accurate full range reproduction of musical material. I have several classical tracks that have sub reproduction in the 17 to 25 hz range which would clearly not be produced by the stock Bose system.




What? You start off as admitting that improvements are subjective. Yet you then state that most people make changes that aren't ideal and they actually degrade the system. How can it be less than ideal or degraded if it meets with their audio needs? How can anyone report all of the flaws when they're subjective to begin with? Probably with a different thread!

Not sure what you mean, but I will try and clarify. As far as "subjective" goes, that was directed at your statement of the purpose of this install and whether this endevour would be "worthwhile" to someone looking for a simple upgrade. An upgrade might seem worthwhile until the person realizes, through self or taught awareness, that the upgrade is actually a DOWNGRADE. Not because their system doesn't play louder or that their subs don't hit harder, but because they get nulls, phase issues, cancellations of various parts of the frequency range. What, if any anomolies, that would be present, would be dependent upon the specific "simple setup" they applied. As long as the system plays the full range of music, accurately, then the rest (sonic signitures, output etc) are subjective when it comes to personal desires. Phase and cancellations problems can be measured and clealry identified. These are not subjective as they can be measured. So when one applies this "simple" system, one could measure and identify these faults.



Bottom line is we all here music differently and any system should be designed for the individual, nothing else.


I agree to this statement when speaking in terms of designing a system to play the full range of music and soing so accurately. If someone chooses to play their subs with a 10 db bump at 70 hz, have their tweeters making their ears bleed, have a gap between their midrange and tweets of 500 hz, or have a setup that has cancellations all throughout the frequency range, thats their choice. But they also shouldn't imply that the system is in general an upgrade. They might have upgraded their ability for their tweeter to make their ears bleed or for their rear view mirror to shake off the windshield, but they are upgrading only certain aspects of the system, while degraded others. As long as all of the pros and cons are divulged then someone can make an iformative decision as to what they are willing to sacrifice and what they aren't. Unfortunately, most people aren't even aware of these problems and rely on others peoples info, but if they heard it, many would not be accepting of them.

 

Bose did. You just proved my point! The Bose midranges receive a full signal extending below 100hz, but mostly 300hz and up, and above 20,000hz as measured with absolutely no capacitor or coil. Only the door woofers and rear woofers have equalization in the amplifier. The tweeter does have the cap, but not all caps are created equal.

I meant drastically different in that the midrange is now blended with the dropoff of the tweeter and the Bose woofer as measured. I understand your point of lacking mid bass and sub bass, but that is beyond the scope of this topic as it calls for separate amplification and a proper subwoofer in a matched enclosure.

Again, I'm not refuting mid bass and sub bass. It's just not part of the topics intent: Simple Install

On the same note, I could state that you are admitting that you are not into accurate full range reproduction of musical material since you have 3.25" mid woofers trying to reproduce below 300hz. Good luck with that! While not a priority for me, this does not mean I'm against accurate sub frequencies. Different topic, different time. That would take a sub and amplification. But if you do that, you will still need to address the other speakers, trust me.

 

Personnally, I like the idea of being able to improve the sound with a simple speaker replacement and will have to go back and re-read this thread concentraiting on the plan and results from Ironchef.

 

In my opinion, for my tastes, an improvement can be made rather inexpensively and safely while retaining the stock Bose amps and signal processing. Replace the stock Bose tweeter with a 3/4" high end unit from the brand of your choice. I prefer silk dome units as aluminum tends to sound too tinny, again in my opinion. Then utilize a crossover that will allow you to bandpass the Bose midrange in the doors and cap the new tweeters. Nice improvement, minimal time and investment.

If anyone's interested, I picked up my set of new JL Audio C5-650's for $250 shipped. I used the crossover, tweeter, and mounting hardware. I then sold the woofers and grills only for $125. **Note- The true beauty of these crossovers is not only can you bandpass the stock mid, you can boost or supress it as well. I have mine set at a 1db reduction.

From JL: As with all JL Audio component speaker systems, a great deal of attention has been placed on the design of the crossover networks, with voicing optimized for in-car performance. Three levels of midrange presence adjustment and four levels of tweeter level adjusHigh-end filter components include precisely wound air-core inductors and high-quality, low-tolerance capacitors. Tweeter protection is also incorporated into the crossover networks.

 

Bose did. You just proved my point! The Bose midranges receive a full signal extending below 100hz, but mostly 300hz and up, and above 20,000hz as measured with absolutely no capacitor or coil. Only the door woofers and rear woofers have equalization in the amplifier. The tweeter does have the cap, but not all caps are created equal.





I meant drastically different in that the midrange is now blended with the dropoff of the tweeter and the Bose woofer as measured. I understand your point of lacking mid bass and sub bass, but that is beyond the scope of this topic as it calls for separate amplification and a proper subwoofer in a matched enclosure.



Again, I'm not refuting mid bass and sub bass. It's just not part of the topics intent: Simple Install

On the same note, I could state that you are admitting that you are not into accurate full range reproduction of musical material since you have 3.25" mid woofers trying to reproduce below 300hz. Good luck with that! While not a priority for me, this does not mean I'm against accurate sub frequencies. Different topic, different time. That would take a sub and amplification. But if you do that, you will still need to address the other speakers, trust me.


Not sure what you are talking about here. i drive a 3" dome midrange.

Do you even know my position on the G's stereo system?

 

Uh, this thread isn't about your system. And yet again your proving my point that the stock midrange either needs replacement via different speaker, amplifier and so on or at least to be bandpassed as I'e done here.

Tell you what, let's agree to disagree and not keep posting away. We're just making it so others will have to scroll through pages to read what I've clearly stated again and again as my opinion.

 

So, after it's all been said and done, adding aftermarket, high sensitivity (~93-95 dB) 6x9 speakers in the rear will NOT improve the G37's (with S.O.W) sound?
Maybe I could improve the sound with a new Stillen Generation 3 CAI!!

 

Yes and no. As a direct replacement there is so little power going to them that it yields no improvement. However, with external amplification it will improve. But that's not a simple upgrade so if you're on a budget, don't bother.

 

Yes, as this thread is getting redundant. My summarization is that simple upgrades are not worth it, but I have said this since day one! One is better off with the stock BOSE system rather than ghetto rigging their car and actually decreasing the overall systems sound quality. If you don't feel that way then I guess our difference is in the definition and criteria of good sound quality. Take care and good luck with your research.

 

Ironchef stated that the JL 6.5" woofer could not produce as much bass as the bose 8", but do you think that the JL 6.5" (or other 6.5" component) would produce more bass when combined with an aftermarket amp with say 100watts per channel?

I plan on removing all bose front door speakers and replacing with a 6.5" component set along with an aftermarket amp. I want to know if I will be reducing overall bass response because I have not decided for sure if I will be adding a sub yet.

Mike

2008 Infiniti G35S Sedan 6MT, Prem, Nav

 

I don't think it's worth doing and here's why:

The Bose speakers in the door is a set of 10" woofer, 3" mid and a tweeter. The woofer works quite well in this application and being a shallow mount design, it fits great and will outperform a 6.5" regardless of power level in terms of bass production. I've tried several times and the replacement of the stock 10" woofer is just not as good as stock IMO. Save your money on this one and look elsewhere like a proper sub/amp set for the trunk.

 

dillyo and ironchef... lil help if you could....

its been a long time since I have tuned an amp so if you too could help me out on the settings on my amp?

Its a JL 500/1v2 and I have it running to one 10. I want it to be heavy on the bass from the amp that way i can tone back the bass a lil on the stock HU.

heres the amps ***** if you are not familiar with it....

http://mobile.jlaudio.com/pdfs/Switches_Knobs.pdf

thanks guys... PM me if you like...