[Lukie]

Apologies if this subject has been covered before. (I did search for a while). I am at the point in my build where I'm ready for stereo installation. I've got the kick panel speakers in front and want to do two more speakers in the rear package tray shelf. I'm just curious as to what fits or goes back there naturally? 6x9's?

At this point, I don't think I want to do much more than just four speakers, and I don't want to try and create a complicated speaker system with separate tweeters and mid-range drivers, etc. I'm old enough to not need to drown everyone else out with bass drum when I pull up to an intersection, LOL. So, I wasn't thinking a sub-woofer is necessary either.

However, I'm open minded to listen to anyone who has had good success creating a nice sounding system. With Dynamat material on every square inch of the interior, and reasonably quiet mufflers, (until you wake them up), how much wattage is necessary to adequately power at least four speakers?

Thanks!

 

[Robert Haas]

I am in my 60's so I would say I am beyond the ear bleeding sound levels of old. That said, I came to realize a full sounding system is not about decibles but it is definitely about a full spectrum. A simple 4 channel system using Mids and full range speakers is substantially improved with a bass enhancement regardless of how loud you listen to your music. 6x9's are never a great choice due to the actual physics of a speaker, and placing tweeters above them and having them all the way back on the package shelf is very inefficient and a compromise that will result in poor tone quality and complicate achieving a balanced range inside the interior.

So here is my 2 cents on sound engineering in the interior of our cars.;

4 channel with a sub out or sometimes referred to as a 5 channel amplifier with 750 watts, 250 RMS per channel can be purchased for under 400. dollars and is the heart of a good system.

Alpine builds a nice unit

Speakers

Think about a sound wave, much like the rings in the water when you drop a stone in it, they always move away from the center in a perfect circle. So building a speaker in an oval shap like a 6x9 has a difficult time producing sound accross a full range and will have a sweet spot where it operates at its design peak. (Usually at higher input levels) thus it is not a consistent device. A simple 6 inch full ranch dual cone speaker in the same location will be a better performer. for the rear deck package shelf. Rockford Fosgate builds a mid range speaker that works very well back there.

Up front a similar size speaker with a tweeter can fill in the highs and it is important to understand that high frequency sound loses most of its energy with distance. So the closer it can be to your ear the more it is usable. On our cars we really can't hide tweeters in the A pillars so having it down in the kick panel is about the best we can do and still remain pretty much integrated.

these are quite good

That leaves the woofer. Now bass is a low frequency component that has little to no angular or directional energy so most systems will merge the low frequency into a single channel and that is perfect for building a 5 channel system that bridges the left and right channel into the sub. We have a convieniant "shelf"behind the rear seat where a small sub box can easily be mounted as well as the amplifier. a small sub box with a single 10" woofer will fill in the total sound of our spacious cabins at low or mellow volumes and honestly if you are going to have a cool car, you deserve to enjoy a cool auditory experience too.

Sorry I got so wordy but I have really learned a lot about this stuff over the years and have been able to hit the mark perfectly in this department in all of my builds.

 

[Fiddy5Coupe]

There is one existing speaker hole in the rear will that will fit a 6 x 9. Duplicate that hole on the opposite side.

 

[Fun56Chevy]

I bought 2 pairs of these for my Charger and they sound great. You get a clean base and crisp cymbals and drums And using a 300w deck. Now I have to get some for the 56 when I install the stereo system.

https://www.bestbuy.com/site/kenwood-6-x-9-5-way-car-speaker-black/6330948.p?skuId=6330948

 

[copymutt]

First, understand you are dealing w/ a horrible acoustics environment w/ no possible optimization for seating. Some compensate w/ volume. I’m utilizing 5” 2way in lower front doors hidden behind the fabric. Two tweeters high on the kick panels. Two subs behind the rear seat.Two 6x9 three way on the shelf. Amps in the trunk w/ dedicated battery. I find I’m constantly changing up the channels and frequencies trying to make it better balanced.

I have a thought on a better tweeter location. Up high on the B pillar there is a little room. Brands similar to the Wedge by Accele are surface mount and this location is close to your ear. Again due to the environment you won’t perceive any stereo when one tweeter is in your ear & the other is across the room. It’s all a compromise.

 

[Lukie]

Thanks to all who responded! Very good advice from all! After talking to my local audio shop, I have a definite plan now.
Thanks again!

 

[Robert Haas]

First, understand you are dealing w/ a horrible acoustics environment w/ no possible optimization for seating. SNIP

I have a thought on a better tweeter location. Up high on the B pillar there is a little room. Brands similar to the Wedge by Accele are surface mount and this location is close to your ear. Again due to the environment you won’t perceive any stereo when one tweeter is in your ear & the other is across the room. It’s all a compromise.
View attachment 331861

I have been giving this post a lot of thought and would like to offer an alternative opinion in regards to component locations and how they actually are designed to function.
The higher the frequency of a sound wave the more directional it registers to our hearing. Stereo by design splits sounds and separates components of a sound track to give a multi dimensional element to it. We all know this. The thing we may not all understand is how that is done. A signal that is transmitted out of our sound systems is in a phased construct. That means the engineers that created the acoustic track we are listening to has separated element of the music to the two channels and also placed the the left and right out of phase by a microscopic amount measured in milliseconds. The human ear receives in the range of 20 hertz to 20 kilohertz yet it samples at about 100 hertz in regards to our ability to determine direction. If the engineer phase the two channels below 100 hertz we instantly detect it, however if the engineer flirts with the 110 to 80 range we hear a fuller more 3 dimensional sound.

All this jargon means that sound is moving about 700 MPH in side our vehicle and the time it takes to travel from one side of our head to another can be detected. So is we hear a sound on one side first it is because it was closer to that ear from the source and transmitted at a higher frequency. . Because our ears are so sensitive we hear high frequencies with much more accuracy and lower frequencies do not give us enough differential to ascertain a true variable, thus they are difficult to ascertain direction.

Tweeters are best if they can be equal distance to the listeners ears. and the phasing by the sound engineer comes into play. Locations are compromised due to our cars construction but one rule is never have a tweeter or even a mid range speaker closer then half the distance of its twin on the other channel. The location suggested by @copymutt on the B pillar would be a poor choice as it would require a tremendous amount of balance inputs to achieve the desired results. As tweeters and some mid range speakers are directional by design and construction "Aiming them towards the center of the vehicle would give a fuller less compromised experience. My personal mounting location of directional components is high up on the kick panels close to the bottom edge of the dash as possible and if they are gimbal mounted point them at the center of the car above the back rest of the front seat.

 

[Bitchin'57]

I just installed a sound system in my '57, which I'm still building. I made kick panels which house Rock-Fosgate 6-1/2" coaxial speakers. I have a pair of R-F 6x9 3-way speakers in the package tray. They are powered by a R-F 75w RMS per channel amp. I built a 1.1 cubic foot sealed sub box that houses a Kicker compR 10" dual voice coil subwoofer, wired for 2-ohm operation. Its powered by a R-F 500w @2 ohm RMS 1 channel amp. I listened to the system before and after the subwoofer installation, and I can tell you that a subwoofer really does make a dramatic difference! I would go so far as to say that a car stereo system isn't complete without a subwoofer.

 

[55Madman]

Thanks guys - I've enjoyed the tutorial...much better when a car guy gives an explanation of a technical issue than going to the local stereo store (do they still call them that?...I used the term 'record store' in front of a teenager and was stared at like I had 3 ears on my head) and being overloaded with unnecessary jargon. One thing that I'll have to accept, but can't quite understand, is how a subwoofer mounted in a trunk doesn't reduce the effectiveness in the passenger compartment to insignificance... I get that lower frequencies are not directional, but it just seems like they would be muffled beyond any advantage of having it. I see it all the time, so will have to accept that it works - just doesn't make sense on its face to me.
JR

 

[Robert Haas]

Thanks guys - I've enjoyed the tutorial...much better when a car guy gives an explanation of a technical issue than going to the local stereo store (do they still call them that?...I used the term 'record store' in front of a teenager and was stared at like I had 3 ears on my head) and being overloaded with unnecessary jargon. One thing that I'll have to accept, but can't quite understand, is how a subwoofer mounted in a trunk doesn't reduce the effectiveness in the passenger compartment to insignificance... I get that lower frequencies are not directional, but it just seems like they would be muffled beyond any advantage of having it. I see it all the time, so will have to accept that it works - just doesn't make sense on its face to me.
JR

It is simple enough. Low frequencies pass through the interior components of the car as if they were made out of paper. This is why you hear bass tones coming from out of a car that you can not even see. The opposite is true in the high bands. They are muted substantially by everything including their own covers.

 

[Lukie]

Thanks again to all who responded to my question! If it weren't for your responses, I would've just installed a low powered in dash unit with four speakers and called it good.

Thanks to all of you, I'm now installing a five channel high powered amp system with better speakers all around and a subwoofer in the trunk. And surprised at how reasonable the cost is.

 

[Robert Haas]

So I spent the day building my sound system using what I was able to accumulate over the last few months searching online for the best deals on high end stuff.

That is as far as I got today.