Calling Sound Engineers

[Nismo280zEd]

I have a 280z 2+2, but I never carry anything in the back seat but tools and junk. So I came up with this idea, build a custom fiberglass encloser on the sides of the car to enclose maybe some woofers and a sub. I was thinking about building this.. under the quarter windows infront of the strut towers, then angle the speakers in the opposite direction, IE the passenger sub point toward the driver, and so forth.

I know the acoustics of the Z were talked about before on here, so I'm wondering if this would sound good, Or if I should stick with the idea I have to put the subs in back so they hit toward the glass.

-Ed

[Guest Aaron]

In my own experience, most of the sound below about 250Hz is quite omnidirectional, so it makes little or no difference where woofers and subwoofers are located or aimed in a vehicle. Also, very little of the music in that frequency range is in stereo, so again, it makes little difference. It does seem to a little more difference in a home theater system than in a car.

 

When placing and aiming midrange speaker and tweeters, you want to keep the front speakers closer to the listeners ears than the rear speakers. (If you don't, the rear speakers have to be played at a much lower volume than the front to make it sound like the band is in front of you.) You generally want to try to aim the speakers at the oposite passenger's head (ie. driver's side speakers aimed at the passenger, passenger's side aimed at the driver's head). That tends to even out the volume difference caused by being closer to one speaker than the other. According to the IASCA manual a few years ago, the effect you are looking for your car to sound like the band is playing on the center of your dash board.

 

Hope that helps a little.

[2126]

In my own experience' date=' most of the sound below about 250Hz is quite omnidirectional, so it makes little or no difference where woofers and subwoofers are located or aimed in a vehicle. Also, very little of the music in that frequency range is in stereo, so again, it makes little difference. It does seem to a little more difference in a home theater system than in a car.

 

When placing and aiming midrange speaker and tweeters, you want to keep the front speakers closer to the listeners ears than the rear speakers. (If you don't, the rear speakers have to be played at a much lower volume than the front to make it sound like the band is in front of you.) You generally want to try to aim the speakers at the oposite passenger's head (ie. driver's side speakers aimed at the passenger, passenger's side aimed at the driver's head). That tends to even out the volume difference caused by being closer to one speaker than the other. According to the IASCA manual a few years ago, the effect you are looking for your car to sound like the band is playing on the center of your dash board.

 

Hope that helps a little.[/quote']

 

I have to agree with Aaron's post 100%. The only other thing I might add is....generally speaking, most interiors of cars are low volume as opposed to a room in your home or a large arena, so putting together a sound system that work well in a car is much easier (except for component space) than a room or arena with large to infinite volume. Additionally, it's advisible to to use good damping material in the construction of your speaker enclosures, to attenuate resonate frequencies. With an undamped low frequency enclosure, the energy produced from a transducer will excite the enclosure walls. The undamped enclosure walls will move like a diaphram (like a speaker cone assy) and in turn produce its own signal and interfer with the original souce of output of the transducer (speaker). These conditions can and will cause phasing problems and in sever cases actually cause cancellations in the effected frequency band. OK, if thats confusing.....just be sure you damp the enclosure...it will sound more precise and improve the dynamics. Hope this helps you out a bit?

[Nismo280zEd]

Ok, so for the sub and woofers, basically whatever looks good will work fine as long as I dampen the enclosers with some brown bread or other sound/vibrations absorption material.

 

So for the midrange, I should spend more money on a quality speaker for the front since it is more important. Then the problem comes, where do you put one in the front, if i put it in the door it will be muffled by the legs of me or my passenger correct? I can easily fit some tweeters on the dash that's no problem. Any thoughts or previous solutions one of you guys have done?

 

thanks for the sound advice

-Ed

[2126]

Forgot one item that Aaron mentioned......the effect of hearing sound that sounds like its coming from the center of your dash...it's refered to as stereo imagining. It's the result of a well balanced system...to be more specific, when the right channel output is identical (best case) to the left channel you will have good stereo imagining. Of course, there are many more variables to address regarding stereo imagining and to actually verify your output signals, requires some fairly exspensive gear. OK, I'll shut up now!

[2126]

Nismo280zED, placement of the tweeters and mids are certainly a problem in a Z. The only solution I can think of is to fabricate custom door panels, to incorperate the placement of the tweeters and mids! I've seen this done on many of the custom tuner cars out there. Sounds like alot of labor to me. Me personally, I didn't even put a stereo in my Z because of all the issues involved...and besides, who has time to mess with a stereo when your grinning from ear to ear from the sound of that sweet L6. Well, that's just my preference anyway. Good luck on your project.

[seth]

Well yes, most of the sound below about 250Hz is quite omnidirectional... Placement will effect output (SPL - Actually bass volume). In several systems that I have installed sub placement, has made a large difference on how loud the subs are. In my 280zx they were the best sounding 8" off the rear glass and few degrees less of an angle, then the rear deck. The best way in my experience to find out how the sub placement will effect your install is to through them just any box and listen to them, in different placements.

 

But that is just my .02

[Guest tejas74260]

Ok' date=' so for the sub and woofers, basically whatever looks good will work fine as long as I dampen the enclosers with some brown bread or other sound/vibrations absorption material.

 

So for the midrange, I should spend more money on a quality speaker for the front since it is more important. Then the problem comes, where do you put one in the front, if i put it in the door it will be muffled by the legs of me or my passenger correct? I can easily fit some tweeters on the dash that's no problem. Any thoughts or previous solutions one of you guys have done?

 

thanks for the sound advice

-Ed[/quote']

 

i disagree with your assumption about the subwoofers. when a sub doesnt sound good...you notice it. plus, with the size of the z...i really dont think you need two woofers unless you REALLY like bass. a subwoofer that would have good SQ as well as get pretty loud is the kicker comp vr. they can be had for less than 100 bucks shipped on ebay. PM me on what speakers you plan to use and i can help you pick a good amp and everything else.

 

Mark

[Nismo280zEd]

Well.. my previous setups... When I first got the car, I put a powered bazooka bass tub in it... mounted it horizontal in the back seat.. it hit toward the passenger sie of the car, worked well, but it wasn't enough bass and the response was lagging in my opinion. So... put the tube in my mom's maxima and ordered a US acoustics 2x200 or 400x1 amp I can look the model number up if ya like i still have it. Then i found a pionner comp sub for 10 bucks on clerance at Best Buy. First I mounted the sub in a fiberglass encloser i made to fit into one of the jump seats. The glass rattled alot since it wasn't bolted down, and It didn't hit very hard. After that... bought some wood at the local Lowes hardware, the stuff that is basically sawdust glued together, forget the name of it. Made a triangular base, calculation the squar volume needed for the sub, mounted that in the back of the z with the amp bolted on back of it. Hits hard as a mother when it gets close to the glass. This is a 10" sub.

 

The setup works, but I don't like it. I loose too much cargo space and can't axcess tools, etc without taking out the sub. So I'd like to move the system either to the sides of the rear (where the body panels are, cust fiberglass enclosures) or... infront of the strut towers since i have a 2+2 and don't use the backseat. Headunit is a basic Blaukpunt with CD removable face, came with two speakers 5"ish.. I think. The reason I was thinking two subs, would be because I know when i move the setup away from the glass i'm gonna loose the punch, so i figured i'd have to add another one to make up for it.

 

I listen to alot of up beat music, punk rock, alt, techno, but i also listen to rap, jazz, slower "bass music" I guess you'd say. So I want the system to respond quickly, but I want some low end punch too. And of course I want it to sound clean. Thanx for all the help with this, isn't exactly my area of expertise!

-Ed

[Nismo280zEd]

brought this back as i just purchased infinity speakers for the stock locations in my 2+2 just behind the front seats on the side. Still pondering sub placement, in a jumpseat well or hatch area.

-Ed

[BrandonsZ]

brought this back as i just purchased infinity speakers for the stock locations in my 2+2 just behind the front seats on the side. Still pondering sub placement' date=' in a jumpseat well or hatch area.

-Ed[/quote']

 

I am planning on putting the sub where the spare tire is now, I have come up with a concept and you can ponder this one,

 

Consider when you have a girl in the car, they generally hate bass anyway so they ask you to turn it down, (IME) so I was thinking:

 

In the "off" or "chick" position the sub is enclosed (sealed) in the back hatch area where it is housed such that it isn't even obvious that you have a sub and someone looking to jack your sterio might even overlook it, just carpet and a round seamline. The sterio would sound like a typical new car, no overly deep base.

 

In the "on" position, when you turn on the radio the antenna goes up and in the same time frame the panel rises and the base is unleashed. I personally would like to see it rise up and tilt and not get out of the way thereby making the lid a sort of bass reflex panel to reflect the sound to the front instead of using the back window. A set of two limit switches would stop the motor, and a on-off-on switch would run it.

 

Then when you have to throw stuff in back, you don't lose any cargo area, you just don't have base at that time.

 

That's my concept, probably done before no doubt.

[Guest 2slo4u]

Just carry a small sub box that you can unplug when you need to carry something. You can use the straps to hold the box steady. When I had my 2+2, I mounted the amps to the backs of the rear seats and had a box with two 12" sealed and facing straight back. You couldn't see the amps because the box was almost level with the top of the seats. A little overkill for good sound, but you can always turn the bass down for people who don't like much.

[Guest JAMIE T]

You should just put a wall of 15's in it....

 

No seriously, Minimal is better. I have been toying with putting Wave-Guides in my Z. Under the dash. An 8" midbass in the kick panels and a 12" sub in the back for the very low frequencies(50 hz and under). The "Wave-Guides" I build myself. I made a mold about ten years ago to lay them up in out of fiberglass. I use Motorola drivers. Basically they are VERY high end tweeters that play into the midrange so the sound is seamless. I used to offer them to customers with very deep pockets since each install was very special. Sometimes requiring a new design of the "horn" section. The sound is distributed across the entire front of the soundstage. I usually use a high powered 4 channel amp of clean quality. My last amp was a Rockford Fosgate Power 800a4. Not to be confused with the more common "Punch" amps. It actaully "dyno'd" at over 940 watts/4. I also like old Tube-Driver, McIntosh, Soundstream and my all time favorite cheater amp, the Orion HCCA225(2 channel stable down to 1/2 ohm). I could power an entire system off the one Orion amp and still put about 250+ watts out of the "25x2" amp. She'd run real hot though, and used a complicated passive X-over network. The best is to run a nice powerful 4 channel amp that has X-over(preferably 24db) for the front and rear sections. X-over the 12" or larger sub at about 50hz and let the midbass driver run up from there. The tweeter(wave guide) doesn't need a X-over since the motorola driver just burns off the frequencies it can't physically play.

 

Basically I saying that with 5 speakers, one amp, and a high end head unit. You could win almost any sound QUALITY compitition(at the local level) over systems with more stuff. That will be $100 for my consultation fee. Thank you.

[Nismo280zEd]

I guess I should describe my car a little. It's a 2+2 but the interior is just about gutted. Back seat no longer exists, and i took the false flooring out for more storage. Thus i was thinking about putting two tens in the wells where the backseat used to be. Also my girl likes bass.

[ITSAV6]

Placing the woofers facing the hatch will increase the amount of low end. It takes several feet for the lower frequencies to complete the "wave". I know you all have heard cars booming loud from 3 blocks and when it gets to you the bass is lessened and increases as it goes by.

With the same enclosure in my 83 280ZT my low end increased 3db on the low end of the spectrum when firing them rearward over facing forward.

The closer to a corner you can put a sub the more bass impact it has(corner loading).

 

"Subwoofer and Enclosure Tips 'N' Tricks

 

Don't go booming into parking lots, bad parts of town, or even school. ESPECIALLY don't go booming into work. You're giving theifs 8 hours of uninterrupted stealing time. It only takes seconds for them to be in and out. Those stickers that come with your subs, put them on your fish tank (or some other appropriate location in your house). You're telling them what to steal. Also, on a common sense front, don't go booming at night through little neighborhoods. That's how sound ordinances start. Don't kill the fun for all of us!

Just like speakers, subwoofers sound best in certain places. Play around with the position of your subwoofer if you have the room. Otherwise just remember subwoofers usually sound best firing rearward.

If you license plate is rattling, stick some sound deadening on the backside and that should do the trick.

Sound deadening does wonders for rattles and road noise, but it also has other benefits such as increasing your SPL and SQ!

For Fiberglass enclosures, if they are made thin, place some sound deadening on the inside, and this will usually make them a little more solid and help separate rear frequencies.

Does your subwoofer leak air where it seals at? Try using bolts with T-Nut backings. Place the t-nuts on the inside of the enclosure. This will ensure a maximum seal and hold!

Does your subwoofer enclosure still leak around the subwoofer? Place a bead of silicone on the enclosure around the subwoofer opening. Let dry before applying subwoofer."