Gummie

http://www.icixsound.com/vb/showthread.php?t=20583

Sorry about the link but I don't want to leach the picture. Bolt/screw your amps down. Don't use velcro or just place them anywhere.

End of story.

1meanGTA

good idea lol. how do you all mount your amps? i'm thinking i'm going to put a sheet of mdf under the carpet there on top of my deadener when i do the hatch area, and screw them into that. right now i've got them screwed (i know about the gas tank) with short screws (i know still a no-no) down into that carpet there. it's not very reassuring with that crossfire especially, thing is pretty heavy.

any other methods besides amp racks?

Gummie

I used a combination of the two. For my first amp I stuck a piece of MDF under the carpet where the amp was and screwed through the carpet into the MDF with 1.5" screws. It sandwiched everything together and kept the amp planted.

When I mounted my crossovers and my second amp I used the same method but then I realized that I had to move everything. When I was taking stuff apart I noticed that my screws never made it to the MDF but everything was still firmly mounted. It was then that I realized that you can screw into the carpet if you use shorter screws (I used 7/8"). I have no problems with this and I tested it by hand by yanking on the amp/crossovers and nothing moved at all.

Stay away from velcro. I doubt that it would hold around a hard corner, let alone an collision.

MrDude_1

im making a fiberglass spare tire well box (so i can keep my already limited convertible trunk room)

i thought ahead while making the box, and the MDF substructure has mounting points to screw my amp into.. directly on the box.

its a smallish box... 10" sub.. but with the amp on the box, i can just undo one weatherpack connector, and pull the box out at the track..

k-roc87

Thanks for the ideas. After my engine swap and tranny rebuild goin to strip the interior and get all the wiring and deadener in before installation.

Sonix

iTrader: (1)

I redid my rear end, so I remove the gas tank at the time to paint the underside of the car. I was also doing my stereo at that time.

I just drilled and screwed the amps to the rear deck, used tamper resistant pin in head hex screws, then cut off part of the screws from the underside so there's only ~1/8" of screw protruding down. Then put undercoating on it all.

If you have to drop your gas tank, that's a good time to screw into the deck and play it safe.

DeLorean247

How about bungie cords?

BruceEmbry

Best places to put amps in a Thirdgen!
1) Under the driver seat, out sight of any peering eyes,
2) In the bottom of your subwoofer box. Works great!

1meanGTA

if you have a small amp, those ideas will work. i wouldnt want anything putting out over 500w rms inside by speaker box though, or over 1kw under my seat. (i couldnt fit either of my amps in either of those places anyway) you need the ventilation to keep your amps cool, unless you build some sort of cooling mechanism.

not to mention you have to put more holes in your speaker box for the power wiring.

Gummie

Haha. I have the GTA power seats in my GTA (gasp) and there's 100% NO space under them, especially the driver's side. 1/2" tops.

I agree with mean on the subwoofer box suggestion. It's fine for lower power amps but it's a good idea to keep higher powered things in a place where some air can circulate around them.

My personal favorite install places are behind plastic trim in the hatch or inside the rear seat.

Brisk

iTrader: (25)

dayum!

BruceEmbry

The Amp in my subwoofer box puts out 100 watts RMS(true power) at less then 0.05% THD per channel So it would be equivenent to most of your amps that claim ~300-500 Watts. As a matter of fact, most the amps sold today are rated at ~20% to 50% THD etc.

So I don't have a low power amp in that box. The amp in my box has plenty of heat sink fins etc and has never shut down from overheating. The heat from the amp can escape the box through the 4 3-inch turned ports. The sub-woofer box has 4 8-inch sub-woofers. I built this sub-woofer box back in 1990. When I first build the box it was passive. I just put in new 8 inch sub-woofers along with amp two years ago.

NEEDAZ

Not hardly. And I don't think you know what he's running...

BruceEmbry

Don't bet on it. FYI, here a pict of my sub-woofer box.

Gummie

I'm defiantly not trying to get into a my ***** is bigger argument (my current substage sucks and I have posted that numerous times). I also don't want to get into an I know more argument, but...

THD level doesn’t have a lot to do with the output of an amp. If it can put out xxx watts it will put out xxx watts. Turning it down isn’t going to make the distortion go away, it’s just going to make it less audible. That is unless the amp is clipping, in which case the distortion will go away. There's also a standard (albeit a crappy one) for rating amps. Finally, a 1200 watt sony amp isn't rated at RMS output; it's sold at peek output. Sony/whoever makes the amp in question will also release RMS specs but they will slap 50,000,000 watt stickers everywhere as a marketing ploy.

Getting back to heat. Certain amps will run a lot hotter/cooler than others. My infinity, for example, gets pretty warm while my ED stays completely cool even though it’s putting out a good deal more power. This leads toward my next point: a low output amp can still get pretty freaking warm. I swear you can cook eggs on one of my friend’s POS no-name amp and it would be lucky to be doing 250 watts.

Aside from cooling in a box, I don’t like mounting amps in (or even on the outside) of a box because it puts additional stress on the amp’s internals due to vibrations.

I know you’re not going to like this, but posting a picture of a box with nothing showing isn’t exactly backing yourself up much

(please note that I’m not going into what I’m running, yada yada. I really don’t care who thinks who has the better stereo. Also note that I didn’t try to back up NEEDAZ and post “fo sho bro. I’m running this shiznat and it’s da bomb yo.” I did think about it but I decided not to start a silly war and I let NEEDAZ’s post speak for its self. I did appreciate his post though because you made assumptions on what I was running. Don’t hate )

NEEDAZ

Didn't mean to drag anyone into anything. I my have miss read the post, but I through there was an offhanded reference to "your" (or someone's) equipment. Just wandering if there was really any personal knowledge. If I miss read the post I apologize, if it was edited to correct content, cool.
My ‘Not Hardly’ was directed at the 20% - 50%THD. The worst you usually see 5% - 10% on HUs, 10% on cheep HUs. I can’t think who would buy or listen to anything that had 50%THD. If it was a ‘miss type’ cool, if you have a spec sheet that shows 50% or know of an amp that is really rated that bad, post the model numbers. I’d like to check them out, I could always use a laugh.
Now, just to through some things out there. The three big things that play into how hot an amp will get are, heat sink suffuse area, efficiency, and output power (an amp that is only 80% efficient will get hotter putting out 500W then 50W). Also note that the load on the amp will not only make more heat in regards to the output stage, but the power supply will also get hotter.
And in general, mounting the amp to the box is considered less then idle because the extra vibration increases the likelihood bad solder connections inside the amp. Don’t mean that you will have problems, just more likely to.
And not a bad looking install. : olive branch :

1meanGTA

my ***** is bigger. much, much bigger

the 2000d in my car is over 30 times more powerful than you 100 watt amp at 1/2 ohm. 0.6% distortion, but at that volume, you dont hear it

NEEDAZ

50%THD you WOULD hear... And 1meanGTA, that's good to know...

BruceEmbry

Hi all,
I did look up the specs on the Sony amp. Its is rated at 200 RMS @0.1THD 20 to 20KHz into 4 ohms loads. The rating at the 2 ohm loads is only 250 watts. I have also read other reviews of the amp and the amp tends to get hot and shut down. I posted the picture of the my box to let the other guy know, that I do know what I'm talking about. Here a little tibet of information you guys should know.

1) It takes double the power to rise the sound level output of an anp 3-DB using the same speaker.

Therefore an 200 watt RMS per channel amp will only output 3 DB more sound that an 100 RMS channel amp ( using the same speakers.

2) The box in the picture above has an acostic gain of 12 DB at 35 Hz. So my little 100 watt/channel amp with the that box has the same bass portential at 35 hz as a Amp with a sealed speaker rated at 800 watts per channel.

Gummie

I'm pretty sure you read correctly because I read it the same way.

Bruce, I'm not sure why you're so fixated on the Sony 1200. I was just using it in my other post because it had popped up in another thread. I’m defiantly not running anything Sony in my car. Yes, you get 3 dB additional output from doubling amplifier power with the same speaker. I can see this being used as an argument for a smaller amp (it happens all the time on e-bay) but it really doesn’t play out very well with most modern subs that are extremely power hungry and require large amounts of power to play at all.

Also, I’m curious for some more information on your box. When you say your box has an 12 dB boost at 35 Hz do you mean that your output at 35 Hz is 12 dB better than what it would be sealed or that you literally have a peek in output at 35 Hz? Box plans would be cool because with the aprox 3-3.5 cubes that are in the hatch I’m not sure how you would pull that off with 4 3” ports.

Edit: yes mean, your ***** is defantly larger tham mine

BruceEmbry

I guess, I got this thread mix-up with another one. As for people on EBAY claiming that a smaller amp is better, it all depends on what you want to do. It always better to go with an bigger amp then what you really need.

But in cars there are considerations regarding electical system loads and max sound pressure levels. When some of these kids get to be my age, they may very well find that have lost some if not all of there hearing.

I have always been careful with amount of niose and loadness that I expose my hearing too. The last time my hearing was check, I could still hear tones beyond 18k Hz.

My box does not peak at 35Hz. 35Hz is a referance for the entire output curve from ~20 to about ~70 HZ. Its been 16 years since I orginaly made the box. But I remember the box has more then 4-cubic feet internal space. I do remember that internal size was optimize for the size of the speakers and ports. As for plans for the box, the box was designed similar to a box that was commercially available back in the 80's That commercially available box, had two sets speakers in a 3-way configuation (woofer, midrange, and tweeter speakers).

I restored the box two years ago and install new speakers and the amp. The box orginal was wired to an passive crossover network. There are 4 8-inch sub-woofers in the box that are wired in pairs to present an 2 ohm load. to the amp. The amp is an old Sanyo unit that was made back in the 80's. I went with it because of the big heat sink fins on the sides.

I know that there was protential problem with the amp overheating inside of the box. But to date the amp has never shut down evern after driving the car in the middle of the summer for hours in 95+ degrees temperatures.

And we all know, the back of these third-gens is no place to mount an amp for two reasons;
1) It gets hot back there during the hot summer months.
2) Amps visable to the naked eye, are just asking to be stolen.

BruceEmbry

When you say your box has an 12 dB boost at 35 Hz do you mean that your output at 35 Hz is 12 dB better than what it would be sealed

Yes!

From memory, I can recall, it has to do with;
1) Size and number of speakers.
2) Internel volume of enclosure.
3) Diameter, length, and number of ports.

Gummie

OK, just checking. I thought you were talking about a 12 dB spike in output @ 35 Hz. Your box still sounds somewhat fishy to me because I don't think there's enough room back there for an MDF enclosure to hold 4 cubes. Sure, 7 cube boxes are possible but they’re a lot larger than yours, made from fiberglass to maximize volume, and involve the removal of a good deal of trim to get at more volume . That's why I asked for plans. Keep in mind that port area doesn't count toward box volume. I could see your tuning/ports being true if your box really holds 3.5 or so cubes with the ports excluded since larger boxes require less port to tune low as compared to smaller boxes do. Smaller boxes (what I was originally guessing for your volume) would require a LOT more port than a 3.5 cube box. I'm not saying that your box is impossible/wrong, I'm just curious for some more information.

BruceEmbry

Hay, the box is a lot bigger then you think. You are only seeing the top 1/3 of the box. You also have to realize that I'm using 8 inch drivers. But you are correct in that my ports had to be vary large to work correctly. The bass out of my box is very clean. But then I not trying to shake the car setting next to me at a stop light.

Gummie

I'm just guessing volume as compaired to what I got mine to be, etc. I know it's a full well box but there just isn't that much room in the well. You could have pulled it off though, I duno.

Back on topic: no matter how you do it bolt your amps down

BruceEmbry

Hay Gummie,
When ever I play the radio, cassetts, or MiniDiscs, what comes out of my car stereo system is music and nothing but music. If a system has an off frequancy balance, distorts, or produce some kind of noise, then its not making music. I vary happy with what I have acheive with the update of the box that I did two years ago. I made the whole system sound better, etc and thats what is all about.

Location componants in my 82 Firebird are
1) Main amp under the driver seat.
2) Sub-woofer amp, in the bottom of the box.
3) Sub-woofer crossover, in the console.
4) speakers in stock locations. Total number of speakers including sub-woofer -->12.
All bolted downed.

INTIMIDATOR Z

iTrader: (4)

ive been thinking of gettin one of the camaro boxes and put one 12" in one side and cut out a square in the other side, put some plexiglass and mount my amps and cap inside of that space. has anyone already done something like that?

jjs_world

I thought the thread was about securring the amps down??? I havnt got any pics yet, but I had a custom fiberglass box built for the rear hatch area, and a custom amp rack that actually hides everything. All is bolted down, so if someone wants it, they are gonna spend about a day to get everything out. Trust me it wasn't easy to fit 2 KX600.1 in the little space in the hatch.

sgt0704

i will post a pic tomorrow, but what i did, was mount them to a board, and put them in the spare tire well. if you have towing on your insurance, then you don't really need a spare tire. that works the best, cause, i can get to them to make adjustments when needed, they stay cool, and there are now wires showing anywhere.

WalkerZ28

That is pretty smooooooth.