sirsomo

I finally got around to building a box for my 2 ID MAXs and I put them in today. They each were getting 1.8 cubes in seperate sealed enclosures placed in the trunk with the factory sub taken out. I hooked them up to my friends 2 Arc Audio 1500 DRs, each sub was getting around 1000w RMS. The electrical system was stock, except for a yellow top battery.:eek: The subs were very loud, Id guess mid-high 140s and really clear. They're not Focal or Velo clear, but not many subs that loud are.

Unfortunately though, the electrical system could not keep up so I couldnt really push them. I can only imagine the voltage drop and how much the the alternator was straining. FWIW, these amps have a max draw of 120A EACH. It looks like Im not going to be able to really run them until I upgrade the alternator and a few other things(no suprise). Also, Im not sure if Im going to keep the subs because they are a little to much for a daily driver. Im thinking one sub, maybe a MAX or maybe something like an Adire Brahma, (XMAX of around 27mm one way).

engin_ear

iTrader: (1)

Interesting.
I know that my stock alternator/battery are straining with one IDMAX when it's cranked, I can only imagine two, especially with the Arc amps. One MAX with a good amp should be enough for a daily driver if you're not looking to blow your roof off. I've found that my MAX sounds great in the 100-120 dB range, beyond that too many random car parts vibrate and create wacky harmonics, you can only sound-deaden a daily driver so much.
Does the Adire Brahma drain less current during attacks? Its XMAX is even larger than the IDMAX's 24.9mm one way.
39 pounds! Anybody know why they're not using Neodymium in these things to lighten them up???

Percy

They probably could use neodymium, but at a greater expense. Plus the spec sheets won't look as impressive...they want the "manly man" factor of the "8 pound magnet" weight. I think the only one using neo magnets for the midwoofer is MBQ and possibly Infinity with their 62f "pancake" speakers.

Percy

Kyle Harty

iTrader: (17)

The amps are drawing current, it won't really matter which sub is hooked to it if the amp is being pushed the same in each setup. The sub can have an effect if it's more efficient so you're not pushing the amp as hard to get the same SPL, or if the impedence curve of the sub/enclosure is higher so the amp isn't working as hard; but generally it'd be the amp rather than the sub you would look at as drawing current.

Rico's Revenge

Place one or two Yellow Tops in the trunk right near the amps, it should solve your problem. When listening to your system at "normal" levels, the alternator will be able to catch up, but when cranked you'll have enough juice to power them.

Also, if you switch to a digital or high current amp you should be able to get the current draw down to a manageable amount.

Lastly, you may want to consider an enclosure similar to mine, especially if you are thinking of using just one sub. It is a fifth-order band-pass. 100% of the output is pumped directly into the cabin through the vent that is placed where the factory sub used to be. I hit 138.6 legal on the dash at a USACi event in Lawton, OK with my one sub hooked to an Orion 900.2 (running at 4-ohms). Another benefit is that your trunk rattle disappears. There is no bass in the trunk and therefore no pressure to make it shake.

engin_ear

iTrader: (1)

Percy: Oh yeah, I forgot this is CAR audio. We're all Manly Men. HO-HO :-)

Kyle:
I beg to differ (friendly, though!).
It is exactly the woofer's efficiency that matters. It is also the woofers physical topology, and how it dynamically draws current. Remember that the woofer IS the load, and the primary cause of the current drain in the first place. For a pure class-A amp, the amp will draw a significant amount of current under no load conditions due to its output circuit topology. But for Class A-B, or Class-D, amps, the primary reason that the AMP draws current is to supply it directly to the load. Also, yes, the amp is being driven with the low-freq input signal, but this does not cause the huge currents itself, the amp's only the middleman here. When the woofer is not moving much and then gets slammed with the attack of a bass drum, it's almost like the startup current for an electric motor - until it gets moving, the currents can be huge. Yeah, you're right, if two subs have exactly the same efficiency, then - on average - for the same listening SPL level, the amp current will be the same. Since each sub's efficiency number is measured statically with test signals, the dynamic currents can still be different, depending on the woofer's electrodynamics/mechanics.

Rico: Great point, yeah, my sub fires right through the stock hole too, so no real trunk rattle!, but the spoiler resonates for some reason and rattles like an SOB. I'm gonna need a lot of rework to get rid of that rattle, not exactly sure how yet.

sirsomo

thanks for the input, i metered the subs this morning, 144 at the dash. Im new to spl, still have a lot to learn. The subs have about 25 hours of play time and are getting louder. I did learn that they are fairly efficient and reach xmax at only 800w, so maybe i can put smaller amp(s) on them. Ive been looking at a digital USamps amplifier( draws around half the amps) , but have no experience with digital amps.

Rico, if you have any pics of your enclosue that shows how its built id like to see. Ive seen it in your car, but it does not show a whole lot. Ive never built a 5th order, maybe ill try it.

Rico's Revenge

engin_ear...if you hold the spoiler with your hand does it stop? If so, have you tried to remove the spoiler and put double sided tape between the spoiler and the trunk lid? That would cushion and tighten the contact between the two. Pay special attention if you have a pointed leading edge on the "side" of the spoiler.

sirsomo...I lost the damn digital picture disk I had from when it was constructed, but I'll try to get some pics of a different one. It is basically a ported enclosure with a sealed chamber on the other side of the baffle board. The airspace and porting is important when building it. I could probably get the specs for you. 144 is a big number. Much louder that I could constantly listen to it for. If it sounds good, I might not jack with it.

Todd

engin_ear

iTrader: (1)

Thanks, Todd. Yeah, if I hold tightly and/or squeeze the third brake light, it stops. I tried putting strip caulk behind the third brake light, didn't work very well. I'll try what you suggest, totally re-do the mounting. I was thinking of filling the spoiler with insulating foam, but I'm afraid it will be too heavy and the trunk lid won't stay up - it's pretty heavy now with Dynamat-original on it.

retrodrive

Well I have two IDMAXs and they are both getting around 1200 WRMS of A/B power (I switched from class D). I have 2 farads in caps and they can't keep up with the new setup. I am upgrading to Xtatic Batcap 400's instead. Do your research and tell me whether you can finnd a better power shortage solution. Oh ya upgrading alt will help but that is optional. Running over 5000WRMS is not as easy as I thought it would be.

Kyle Harty

iTrader: (17)

Yeah, a different viewpoint than I was taking, and also alot more technical than my knowledge on the subject. I stand corrected, and I hope my original comments weren't taken as anything but friendly, I don't mean to sound like an a$$. I've seen a few of your posts and respect your knowledge.

Rico's Revenge

Sup' Dude?

The BatCap should help, but it is still not as good as having an extra battery or two VERY close to the amps. Also, for future reference for some of the newbies, caps must be used within 18" of the amps or you'll lose voltage.

High wattage is just like High horsepower, its just more to break!

Our "big" truck (LOL!! Its an S-10) with the (8) Hifonics Colossus sees 24,000 watts! Not a mis-type! 6000 to each sub...3000 to each voicecoil! We make sure it gets enough power by using (6) 86lb. WheelChair batteries. The longest power lead run is still less than 18" from terminals to amp. Even with all this, we still get voltage drop after long hard use.

BTW, up until last week we were charging it using the stock alternator. Now it has been replaced with (2) 180 amp units.

Power is everything! I still suggest adding one or two yellow tops in your trunk next to the amps fuse them properly and crank it!!

Todd

PS...I'll try to get some pics this weekend and pop them on so you guys can check this out...its WILD!

sirsomo

I haved used caps in the past and was never that impressed with them. I think the first thing im going to do is get a new alt. or get it rewound. Probably add a 2nd yellowtop after that. I think ill also use a line driver, because im switching back to the factory head unit. If that doesnt work, ill just have to throw the subs off a bridge.

Rico's Revenge

Try the yellow top first. If your system is pulling enough power to make your current one drop that quickly now, the alt. still wont be able to completely keep up. You have to have somewhere for the extra juice to go. Plus a yellow top is around $100. A alternator rewind will cost you $300 and it will only go so high (probably 140 amps, I believe stock is only 85).

Rico's Revenge

All right, I snapped a couple shots just now of my friend Chris' S-10. He competes in Mod 601+ in USACi. The Amps are Hifonics Colossus. You can see some of the batteries undor the one amp that is displayed. All the conections are short (though unhooked in this picture).


I didn't get a pic of the subs since they are out right now. But it is a wall with (4) Treo CSX 15s.