jdmfetish

iTrader: (3)

as long as your happy that is what mattes, as far as how good or how bad it sounds is 100% subjective

i have fed as much as 10K watts, glass is fine

JMII

I think the glove box is just too "near field" to work well in bass reproduction. Your physically too close to the sub and the bass can't expand to fill the area. This is why it sounds so localized and flat. It must have something to do the wave length and cabin gain. Like in home audio there are certain "dead" zones where bass cancellation occurs. The glove box seems to be that zone in the Z relative to the listening position. I'm not saying you can't get good sound from this location, its just not optimal. A single smaller sub and low power levels make it even more challenging.

I did a similar comparison: I had a custom 8" sub box I built that fits between the center console and the rear seats of my Dodge Dakota Quad Cab. I tested this box in the hatch of the Z as if it was a corner box. Then I made a custom enclosure for the glove box area. Since it was just an 8" I was able to get a real enclosure, made of wood and totally, sealed stuffed in there. The sub fired thru the stock opening as the box was attached by bolting it to the stock mounting plate under the BOSE grill. Lots of the Dynamat was used, but it didn't really help, all the plastic back there rattles like crazy.

Well the corner sub sounded SO much better! Deep, full bass. Granted its an 8" so its not loud but it sounded very similar to my truck setup which is perfect for me. Now the subs I used were different (Kicker vs Infinity) but were installed in their correct air space, both were sealed and feed by the same amp with around 300 watts. Both were equalized by an Alpine Imprint system that automatically adjusts for reverb and frequency. So it was a good location vs location test. I still have the 8" behind the seat (due to being lazy) but will switch to a 10" in the corner at some point because I know it be so much better.

I also tried doing a 12" downfiring in a SRQ glove box - it just rattled the entire interior like crazy, it came out after only one month. Once again regardless of Dynamatting as much metal as I could back there the various plastic bits vibrated and squeaked constantly.

All my testing indicates the glove box is worst place for a sub in the Z. Front firing, down firing, sealed, ported, free air... doesn't matter. Under the strut bar, spare tire location (via a false floor) or in the corner like Wicked CAS design are all better locations.

2Cool4Skool

iTrader: (2)

“100% subjective”
That’s incorrect. If the box is flexy, like the one I made using the plastic glovebox, it will sound terrible. There’s no ambiguity whatsoever. It’s no longer subjective when the install is compared with a sub enclosure that’s already proven to work well.

“Localized and flat” as a location problem
Location is not the reason for that problem. This is a problem with a plastic enclosure that flexes too much. I made a box out of the plastic glovebox like this guy:
https://my350z.com/forum/audio-and-v...a-sub-box.html

It sounds like you’re conflating “glovebox location” with “glovebox enclosure”. I guess its kind of hard to describe without pics. Check out the thread by TURBOROADSTER above. I tried making a subwoofer box out of the glovebox just like he did.

Anyways, it sounded like a great idea so I tried it and it just does not work. The sound changed dramatically after I took out the glovebox enclosure and installed the sub back in using the body as the enclosure. Right now, the only thing wrong is that it probably has the wrong volume.

In your case, you’re comparison method is faulty which leads to a faulty conclusion. You should be listening at both locations using the same enclosure you made for the glovebox location. Unless you do that, you can’t say this is a location problem.

If the one in the corner sounds much better compared to the one in the glovebox location, then the “problem” is either the sub or the box (volume, leak, polarity, etc)

Different drivers will sound different. My Infinity Perfect 10 VQ on the left sounds a lot different than than the Infinity Perfect 10.1 on the right. The 10.1 is much more efficient (i.e. louder) but produces slightly less bass than the VQ version. The VQ version requires much more power to produce the same SPL.

This is my tested locations and types of drivers:
1) Back trunk - 1.0 ported box , 1.4 ported box
2) Front seat - 1.0 ported box
3) Right glovebox area - Perfect 10.1 using the body as enclosure
4) Left glovebox area - Perfect 10 VQ using the body as enclosure
**Boxes were all Perfect 10.1s

I know that location is the least likely sound problem. There is no difference between under strut and trunk area. With the front seat removed, I had the 1.0 box in there and it does sound slightly different, but not a big deal. Location is not that big of deal because a properly functioning sub’s low-frequency sound waves are non-directional; unlike tweeters, where high frequencies are directional.

Although I haven’t tested the corner area, I suspect it would sound the same as the trunk and under strut which is only a couple feet difference.

The “corner loading” claim sounds like a marketing thing that originated from installers. Installers will sell the easiest build locations because the quicker they can build it, the more money they can make. That corner location is “easy”. You just remove a few pieces. The glovebox area is much more difficult. The seat and plastics need to be removed, the holes plugged up, the volume correct for each driver. Because of the different vol. requirements for different drivers, you’d have to make sure the volume is correct which is almost impossible to do without taking time to test it. Testing the glovebox area using the “body-as-enclosure method” is too time consuming. And don’t forget the contortions to the body to build within the glovebox space. You can’t money if you get injured. Smart installers would rather sell the “corner loading.” and spend more time building a good-looking install. If the install looks professional, the sound (even if faulty) will sell itself to the client.

Side note: Same with kick panel pods. Note how you don't have to run wires through the molex on the door. It saves time and you can sell the client some pods.

Rattles:
I forgot to mention this in my past posts. I took out all the plastic and stuck some thin closed cell insulation on the panels before I installed them back. I used the kind with foil on top. I peeled off the foil because when that falls off, it will give off these “tinkling” noises. This took some time but it was worth it. I do not have any plastic rattles. Dynamat will do nothing to reduce plastic rattles. Dynamat is only used for reducing resonance and you don’t need much to do that.

Left side: Infinity Perfect VQ, with 460 rms watt amp, ported out the back using the body as the enclosure. No rattles other than the rear window distorting. The sound is properly non-directional.

jdmfetish

iTrader: (3)

subjective, let me clarify , your finished product that you are using and happy with , how this sounds as far as how good or how, not so good , is subjective to the person hearing it

if i heard it and i have not , i may, or may not think it sounds good

i am not a fan of the OEM location for the sub

you have not even begun to scratch the surface of box in hatch , i have built and used a dozen enclosures over the past 11 years for the z, with subs and ports faced in many different directions , output and sound changes dramatically between them

like i mentioned if you are happy with what you think sounds best that is great

i respectfully disagree with most of your post , no biggie

enjoy what you have

dboyzalter

iTrader: (3)

My new sub sounds good.




Its mounted in a nice enclosure in my living room.

JMII

Not necessarily. There are null areas in any space, areas where bass cancellation or reinforcement occurs. I think relative to the listening position (driver's seat) the glove box location is not optimal for low bass performance.

I did similar testing with my home audio system and a dB meter - the volume has peaks and dips, plus the frequency shifts as you move around the room. Just because low frequencies are non-directional doesn't mean they are not effected by room or cabin acoustics, it just means your ear can't determine the source of the sound. Thus the bass seems to come from all around you but the sound quality will vary depending on location. Granted some cabin acoustical problems can be over come with tuning and power.

I agree with jdmfetish - as long as your happy with the sound that is all that matters.

rodbass

"like this one:"....?

Can you link to or describe the box?
I just got my new(to me) Z and bought a 10" sub that I thought I could just drop in as a replacement. If I need a box, I don't know where to get one.

MicVelo

Triple posting is frowned upon.