MP3Car.com - View Single Post - Can someone help with my questions about my install?

WhiteRabbit · 08-27-2005, 01:10 PM

I dont know, that advice doesnt sound right to me.

the first recommendation was to keep the rears. there are SO MANY reasons to ditch the rear speakers! from the sq standpoint that has been brought up, it prevents phasing between the rear and front speakers. this will destroy any sonic realism we are trying to create! The second point source of sound will also pull back the sound stage, bringing it closer to the head rather than far forward. one of the major concepts of "SQ", is to have a stage placed far ahead of the listener! I have heard some benefits of raising the stage by running rear speakers, but its so few and far between, why add needless complexity? Rear speakers are not important to sound quality in a 2 channel stereo system at all!

and if all those "sq" reasons are not enough to make someone want to ditch the rears, how about having those large open holes to let all that nice bass into the cabin? its like having your seats permanently folded down!

Now, dont get me wrong, I dont advocate everyone to go to their car and pull the rears! especially with stock systems, or people running *either* infinity reference or CDT classics up front, removing the rears can often create a massive midbass gap between the stage and subwoofer that is absolutley insurmountable. But we are obviously dealing with a guy who will have plenty plenty of midbass support to cover any potential distance between his midrange driver and the subwoofer!

whats this about overpowering and underpowering speakers? not even an issue here! only two things kill a speaker, and it has nothing to do with power! mechanical overload and thermal overload. (and one can argue fatigue.) But certainly not underpowering! for a good read to straighten out this underpowering issue, I suggest everyone reads the following resource: http://www.caraudioforum.com/vbb3/sh...d.php?t=224025
its the last Ill mention anything involving blowing spekaers or power. the amp he has now is fine. no blown fuses (unless he puts a 10 amp-er in there), no blown speakers (unless he tunes like a retarded 3rd grader. I assume he is smarter than that.)

before I get to crossovers, I had one question you brought up about speaker position. man, you are right about how nothing can be more important than speaker position! ... But first you say dont put the midrange and tweeter more than 24 inches apart. THEN you say they need to be closer to ear level. these contradict each other! finally, in an attempt to resolve the conflict, you suggest putting the tweeter in the door 13 inches above the mid, whether its in a kickpanel or in the door. wierd!

the fact of the matter, is that in a 2 channel stereo system designed for "sound quality" (and nothing in this thread is more important than that term, by a large margin) the tweeter can absolutly go in the kickpanel. The best car I ever heard had tweeters sitting on a pair if t-shirts in the kickpanel area! (you may opt to believe the car sounded like crap as a result, thats fine. your perogative. I know the truth.) realistically, we put the tweters on the a-pillars for a reason. our legs do a great job of blocking highs, and certainly would if the tweets were 13 inches above the floor! even in the kicks we cna block them. finally, its very very easy to have issues with a low soundstage with the tweets on the floor. with everything *finely* tuned, usually the midrange doesnt have too much of an issue rising to the occasion, when properly seated in the kickpanel area.

so up high it is, for the tweets! the only two problems we have are reflections, and uneven speaker path lengths. dash mat covers one, and balence covers the other one! set!

I do agree however, that a more on axis direction to point the tweeter (towards the head) prevents shallow rolloffs and make the whole stereo "shimmer" more, if I may use an esoteric psychosomatic term. (if I wont be allowed to, simply ignore that I said it.)

whew! but what about the crossovers? I would be a fool to suggest you were mistaken to say a crossover isn't important to the system. in fact, ill go farther, to suggest it is THE most important part of the system! (minus speaker choice of course) you are right, he definitely definite needs to cover that. But he doesnt need to purchase a brand new passive crossover, the one he has now is just fine!

the next part I am writing for drew, not for you spyder, so its gonna be some stuff you already know. Drew, what spyder was trying to say when he was talking about the crossover, is that its important for each speaker to get its proper frequencies. I bet even you know this very well. But when we think about the nitty gritty, youve got a full four way system! that means your subwoofer needs a low pass filter. your tweets need a highpass filter. and your midbass and midrange both need *bandpass* filters! thats a TON of filtration!

so what do you have? you have your passive network, thatll highpass your tweeter, and lowpass your midrange. your sub amp will lowpass your subwoofer. we are left with three filters we still need!

now, I dont know if your amp will be able to do that. if it can't, and your radio can't compensate, you need an external crossover! I highly recommend an aftermarket active crossover anyways! (dont worry abotu the passive one) but Ill assume you arent looking for world class sound quality (read: world class expensive) and so you can get away with less tuning ability than youd ideally need.

I am going to repeat this, for everyone. An active crossover gives you more tuning ability and more control over your sound than any radio, amplifier, equilizer, or signal processor (minus those with crosovers) hands down. play with one, and its easy to see why your crossover cutoffs, and chosen slopes, simply change the whole dynamic of the speaker more than simply adjusting an EQ slider will. its amazing the control over the sound we have!

but its expensive to run EVERY speaker in the car individually amplified with its own eq, ta, and crossover settings, isnt it? expensive signal processors, expensive EQ's, expensive crossovers, expensive amplifiers, lots of wiring, etc. pain in the butt!

so we are going to cheat a little bit. we will KEEP the passive crossovers you have now! what you can do, is put your midrange drivers in the kicks, tweets in the a-pillars (remember, kicks are fine, be concerned about leg blockage, but they perform very well in kicks too!) and simply run the front channels of your kicker 4 channel amp to the passive crossover you have now. then simply use the onboard crossove rto highpass the whole system (oh, say, 120 Hz. youll have to adjust this yourself, of course, fine tune the sound you want.)

You now have everything covered minus a bandpass crossover for your midbass driver!

here is where I try to get a little tricky when I can. Sometimes, amplifiers have rca outs that will take a setting from the onboard crossover. for example, you MIGHT be able to set your kicker 4 channel amp to, say, highpass the front outs at 120 Hz, then lowpass line level signal from 120 Hz out the preamp outputs (the cutoff would be controlled by the same dial as the front highpass cutoff. its not ideal, as you can-not independantly adjust the frequency, but remember that cost/performance ratio? itll at least work!) then you can simply piggyback the outputs to the rear inputs of the amp, and use THAT crossover as the highpass (say, 55 Hz cutoff) for your midbass!

and now you have power to your midbass drivers, and they are bandpass filtered!

amp can't do it? youll need an external crossover. maybe you want the independant control anyways.

with the equipment you have now, you MUST use your passive filter that came with the component set. I assume you had planned to run that anyways. thats fine, actually!as long as we arent talking about world class "sq", (and when were we ever talking about world class sq?) then we are allowed to take liscence to do so!

but to spend money on a 3 way passive filter? that simply makes no sense.

the only reason to get a new amp is if you want to run a fully active system. expect big cost increases. I say forget about it till you want that kind of tunability, especially when you can get everything running well for a daily driver with what you have now (minus MAYBE needing a crossover)

08-27-2005, 01:10 PM	#5
WhiteRabbit Maximum Bitrate Join Date: Jun 2004 Location: Bay Area, California Posts: 644 My Photos: ()	I dont know, that advice doesnt sound right to me. the first recommendation was to keep the rears. there are SO MANY reasons to ditch the rear speakers! from the sq standpoint that has been brought up, it prevents phasing between the rear and front speakers. this will destroy any sonic realism we are trying to create! The second point source of sound will also pull back the sound stage, bringing it closer to the head rather than far forward. one of the major concepts of "SQ", is to have a stage placed far ahead of the listener! I have heard some benefits of raising the stage by running rear speakers, but its so few and far between, why add needless complexity? Rear speakers are not important to sound quality in a 2 channel stereo system at all! and if all those "sq" reasons are not enough to make someone want to ditch the rears, how about having those large open holes to let all that nice bass into the cabin? its like having your seats permanently folded down! Now, dont get me wrong, I dont advocate everyone to go to their car and pull the rears! especially with stock systems, or people running either infinity reference or CDT classics up front, removing the rears can often create a massive midbass gap between the stage and subwoofer that is absolutley insurmountable. But we are obviously dealing with a guy who will have plenty plenty of midbass support to cover any potential distance between his midrange driver and the subwoofer! whats this about overpowering and underpowering speakers? not even an issue here! only two things kill a speaker, and it has nothing to do with power! mechanical overload and thermal overload. (and one can argue fatigue.) But certainly not underpowering! for a good read to straighten out this underpowering issue, I suggest everyone reads the following resource: http://www.caraudioforum.com/vbb3/sh...d.php?t=224025 its the last Ill mention anything involving blowing spekaers or power. the amp he has now is fine. no blown fuses (unless he puts a 10 amp-er in there), no blown speakers (unless he tunes like a retarded 3rd grader. I assume he is smarter than that.) before I get to crossovers, I had one question you brought up about speaker position. man, you are right about how nothing can be more important than speaker position! ... But first you say dont put the midrange and tweeter more than 24 inches apart. THEN you say they need to be closer to ear level. these contradict each other! finally, in an attempt to resolve the conflict, you suggest putting the tweeter in the door 13 inches above the mid, whether its in a kickpanel or in the door. wierd! the fact of the matter, is that in a 2 channel stereo system designed for "sound quality" (and nothing in this thread is more important than that term, by a large margin) the tweeter can absolutly go in the kickpanel. The best car I ever heard had tweeters sitting on a pair if t-shirts in the kickpanel area! (you may opt to believe the car sounded like crap as a result, thats fine. your perogative. I know the truth.) realistically, we put the tweters on the a-pillars for a reason. our legs do a great job of blocking highs, and certainly would if the tweets were 13 inches above the floor! even in the kicks we cna block them. finally, its very very easy to have issues with a low soundstage with the tweets on the floor. with everything finely tuned, usually the midrange doesnt have too much of an issue rising to the occasion, when properly seated in the kickpanel area. so up high it is, for the tweets! the only two problems we have are reflections, and uneven speaker path lengths. dash mat covers one, and balence covers the other one! set! I do agree however, that a more on axis direction to point the tweeter (towards the head) prevents shallow rolloffs and make the whole stereo "shimmer" more, if I may use an esoteric psychosomatic term. (if I wont be allowed to, simply ignore that I said it.) whew! but what about the crossovers? I would be a fool to suggest you were mistaken to say a crossover isn't important to the system. in fact, ill go farther, to suggest it is THE most important part of the system! (minus speaker choice of course) you are right, he definitely definite needs to cover that. But he doesnt need to purchase a brand new passive crossover, the one he has now is just fine! the next part I am writing for drew, not for you spyder, so its gonna be some stuff you already know. Drew, what spyder was trying to say when he was talking about the crossover, is that its important for each speaker to get its proper frequencies. I bet even you know this very well. But when we think about the nitty gritty, youve got a full four way system! that means your subwoofer needs a low pass filter. your tweets need a highpass filter. and your midbass and midrange both need bandpass filters! thats a TON of filtration! so what do you have? you have your passive network, thatll highpass your tweeter, and lowpass your midrange. your sub amp will lowpass your subwoofer. we are left with three filters we still need! now, I dont know if your amp will be able to do that. if it can't, and your radio can't compensate, you need an external crossover! I highly recommend an aftermarket active crossover anyways! (dont worry abotu the passive one) but Ill assume you arent looking for world class sound quality (read: world class expensive) and so you can get away with less tuning ability than youd ideally need. I am going to repeat this, for everyone. An active crossover gives you more tuning ability and more control over your sound than any radio, amplifier, equilizer, or signal processor (minus those with crosovers) hands down. play with one, and its easy to see why your crossover cutoffs, and chosen slopes, simply change the whole dynamic of the speaker more than simply adjusting an EQ slider will. its amazing the control over the sound we have! but its expensive to run EVERY speaker in the car individually amplified with its own eq, ta, and crossover settings, isnt it? expensive signal processors, expensive EQ's, expensive crossovers, expensive amplifiers, lots of wiring, etc. pain in the butt! so we are going to cheat a little bit. we will KEEP the passive crossovers you have now! what you can do, is put your midrange drivers in the kicks, tweets in the a-pillars (remember, kicks are fine, be concerned about leg blockage, but they perform very well in kicks too!) and simply run the front channels of your kicker 4 channel amp to the passive crossover you have now. then simply use the onboard crossove rto highpass the whole system (oh, say, 120 Hz. youll have to adjust this yourself, of course, fine tune the sound you want.) You now have everything covered minus a bandpass crossover for your midbass driver! here is where I try to get a little tricky when I can. Sometimes, amplifiers have rca outs that will take a setting from the onboard crossover. for example, you MIGHT be able to set your kicker 4 channel amp to, say, highpass the front outs at 120 Hz, then lowpass line level signal from 120 Hz out the preamp outputs (the cutoff would be controlled by the same dial as the front highpass cutoff. its not ideal, as you can-not independantly adjust the frequency, but remember that cost/performance ratio? itll at least work!) then you can simply piggyback the outputs to the rear inputs of the amp, and use THAT crossover as the highpass (say, 55 Hz cutoff) for your midbass! and now you have power to your midbass drivers, and they are bandpass filtered! amp can't do it? youll need an external crossover. maybe you want the independant control anyways. with the equipment you have now, you MUST use your passive filter that came with the component set. I assume you had planned to run that anyways. thats fine, actually!as long as we arent talking about world class "sq", (and when were we ever talking about world class sq?) then we are allowed to take liscence to do so! but to spend money on a 3 way passive filter? that simply makes no sense. the only reason to get a new amp is if you want to run a fully active system. expect big cost increases. I say forget about it till you want that kind of tunability, especially when you can get everything running well for a daily driver with what you have now (minus MAYBE needing a crossover)