I think that ratio is a bit over rated.

 

With that equipment you're limiting yourself some, but you can still end up with a nice sounding car that can be expanded upon later. You've just got to take the time to do the work right. I'm not far from you, I'm on 49th about 1/8 mile north of 110th ave. I'll be glad to look over your car and items and give you my SQ suggestions to make the most out of what you have.

 

Quote:

Originally Posted by blownrunner

1) Mount your mids and tweeters as close together as possible, then as far forward as possible, and then as par apart as possible, while being on axis as possible. This will reduce path length differences. You want the drivers seat/listening position to be in the 'sweet spot'. Most of the imaging comes from your midbass speakers.

2) Find a place to mount midbass drivers as close to you mids/high, and make sure they are beefy enough with enough power to play down to about 70hz or so. This will eliminate the 'sub sound from the rear' problem. The problem is that midbass might need an enclosure which requires a larger mounting area. People have used the doors dynamatted and sealed somewhat as an option.

Getting this optimized will greatly reduce problems with equalization setup down the road. From the inexperienced ear's perspective, you should hear stereo but it should sound as if there is only a single speaker playing in the center of the dashboard forward of the windshield for all frequencies: Mids, midbass, and highs. Good luck with that... I have been trying to do that for 15 years and although I have gotten closer, there is room for improvement!

I know it is generally accepted that 6x9's are to be hated. Not sure as to why, but that is on the docket to learn about. With that said, this is what I was thinking so far as the set up...

There isn't a lot of space to get a lot of angle at the kick panel, but from what I've been able to measure out so far, it seems like I can get enough angle to get both speakers pointed to the dome light. So the driver's seat is only going to be a little bit off axis. The speaker is a 5.25 inch. The tweeter is an inch. Maybe 1.5. I'm not sure since it is in a little case thing I've not taken apart yet. I was thinking putting that at about 4-5 o'clock in relation to the 5.25 (on the passenger side) So the center of the tweeter is between the 5.25 and the door, and below the horizontal centerline. (I hope that makes sense. I attempted to draw it in paint... and yeah... that didn't work. lol) The concept that I'm going for is to make a frame to bolt the speakers to, that attaches to a modified stock kick panel so that it all bolts up to the stock kick panel bolt locations, then has a little rubber foot that supports the weight on the speaker side.Again, hard to describe without being able to show it... I'll try to take pictures while holding the speakers in place.
Anyway, that's the kick panel, then I was going to put the 6x9 in the door. I can't really angle the front side of it out any, Maybe a few degrees, gotta take the door apart to know for sure, but I know I can get some upward tilt. so instead of the speaker being in the bottom of the door, mounted like I, it will be more like / . I'm hoping that will get the axis of that speaker a bit closer to the 5.25.
There is some space to work with in the door to get the 6x9 in there, but not enough to build an enclosure too. They have those solid foam bucket things they sit in. Not sure what they are called, but I guess they are supposed to act like an enclosure. I'm trying to get the 6x9 in there horizontally. If not, I know it will fit vertically with minimal effort. Since I know there won't be space for a real enclosure, I was going to build the door to act as the enclosure. A piece of dynamat on the outer skin. a layer of foam, probably overkill, or something similar. spray some rubberized undercoating where the outer skin meets the inner skin. It isn't air tight as it is basically just folded over itself and spot welded. Then put a few pieces of dynamat on the inner skin. Then take a think piece of plastic, like from the factory, and use that rubbery goop rope stuff, forget what it is actually called, and the link I have is on my home machine, and I'm at work. Anyway, use that stuff and the plastic to basically seal the door off, kinda like they do from the factory. At first, I wanted to then put a layer of foam, then a layer of mass loaded vinyl, but then there wouldn't be space to bolt the door panel back on, so I took a little different approach. I'm gonna cut the vinyl piece a bit smaller, so it fits just inside the door panel, about an inch, give or take. Then attach the foam to that. So that way, the vinyl and foam are attached to the panel, and not the door. and when the panel is attached to the door, the foam will be tight against the door. It'll be a tight fit, but still allow the door to bolt up and all of that.
Whatcha think?
Over kill? bad plan?
more simple way to go about it?


I also have another pair of 5.25inch speakers. I was thinking about reversing the polarity and mounting them a little ways back in the hatch. Reversing them to avoid the wavelength/pattern conflict but still having them there to assist with the sound when the t-tops are off.
Good idea?
Wasted effort?
Better way to make it work?

I'm planning on some sort of audio processor. gotta do more research into them, but rumor has it, they are programmable so that, at a flip of a switch, they can go from a good sounding, balanced sound with the T-tops on, and then go to a set up better adjusted to compensate for the tops being off. It isn't quite as open and challenging as a convertible, but same basic idea.
Any guidance as to how to attack that challenge?

 

Thanks.

Yeah, the more I learn about all of this fun, the more that statement gets reinforced as true.

eh...If it is anything like engine performance, it is probably closer to 80% to 20% once you are beyond stock paper speakers realm of course.

That's exactly what I'm going for with this build. nice sounding, but expandable.

The help would be awesome. I'll hit you up when I get this 240sx build done and can get my Z in my garage.

 

I'd be very careful how many drivers you drop in a given area. More drivers will give more volume, but kill SQ. Putting a 5.25 comp set in the kicks and then 6x9 coaxials in the doors will do more to hurt the sound than help. Once you've done that now you have scattered the point sources all over the front of the car, and any hope of staging and imaging is gone. The tonality difference between the speakers is going to have a severe negative effect on the overall clarity as well. The ONLY way that will work right is if you run the 6x9's as a midbass only, and then transition the midrange over to the 5.25's....and even that isn't going to work perfectly but its a better option than letting them overlap.
Some of the best sounding cars on the planet have only a front 2 way comp set, and a woofer. Simplicity often rules in the SQ world.

Also be careful of the angles you work to achieve. Some speakers actually sound better off axis than on, because they were intended to be mounted into a door location. In your case i dont know if it will matter, there isn't much in the way of engineering behind those speakers. I build mock-up panels and listen to a variety of stuff for many hours before building a set of kicks. You might try 30 different variations of angles for each driver before you nail it. People wonder why good kicks are so expensive to have made, that's why.

 

Didn't know that.
most of the set ups I was seeing had the smaller speaker in the kick, then another larger one in the door.

I was planning on keeping the frequencies separated.
these 6x9's sound exponentially better in the lower ranges. Almost seems like they were intended to run as the subs, or at least strictly bass and they just slapped a coaxial in there to make it sell better...

 

Ding ding ding, ten points for you on that one! Flashy crap = more sales for some reason.
I've done 3 ways with the midbass in the door, midrange and tweet in the kick. I'd highly suggest a good processor to make it sound right, becuase being able to time align, EQ and xover each driver makes a HUUUGE difference in that setup. MS8, BitOne, or the older discontinued Alpine are the best options.

 

oh yeah. totally planning on the processor...
I'm starting to look into the MS8 and the BitOne. I've heard those mentioned other places too.


any advice on my idea about the 5.25's in the rear?

 

That would be ok, but i wouldn't just reverse their polarity off the bat. I'd try it both ways and see what you hear. There's a good possibility you may not need to flip the polarity on them, but thats going to depend on where you actually mount them, their angles, etc. I normally start with all drivers running the same polarity and go from there.

 

I'm assuming that the farther back, the better, right?

would it be better to mount them flat, so they are pointed straight up? Or mount them on their side so they are facing the front of the car?

I could technically make an angled mount so they point where ever would be best...
I just don't know how much they would clash if I tried to point them to the same spot (ie, the dome light) as the front speakers... Or if it would be better to angle them parallel to the hatch.
These are more for when the tops are off. I figure I would have them set decently low for the tops on setting, then have them set higher to compensate for the tops being off.
I'm not thinking a good sound stage would even be possible with the tops off, so I was thinking that it would be best to just have enough volume to compensate for it...
I'm kinda shootin' in the dark when it comes to that... Still have some research to do...