need point blank advice

Systems

im buying a system for my 1980 thunder (dont let the age fool you, its in damn nice shape) and i have a few questions.

i work at a big electronics store, so i buy all of my equipment at cost - roughly half price. right now im looking at a pair of polk momo 12" subs, directed 1100d amp, the momo 6.5" speakers w/ crossovers, kenwood 6x9 4-ways, 2 rockford fosgate 300 watt 2 channel amps, and a pioneer head unit with 50 watts mosfet, max :P . as far as i can see this is one hell of a system.

i know that ill only be getting 900 watts 2 my subs because they will be at 2 ohms, which is ok. now a few dumb questions.

1. does the power from the head unit and the speaker amps stack so that ill be getting ~180 watts to each one? or will i only be getting 150?

2. if i put dynamat in my trunk and all that. which way should the subs be facing? i always hear towards the rear, is this so it reverberates?

3. about the subs, because the have only one voice coil, can they still be wired in parrelel? prolly a stupid question but its an expensive system to be guessing with.

im not a complete newbie with speakers and such, ive just always been into home audio and dont know too much about cars... thanks in advance for any advice!

goingganzo

i fse my subs tward the back you get less thd in the cab

PoweredByDodge

first -- the dei 1100d is a good solid amp -- you'll be pleased with it. the rockford 300 watt 2 channels... those are probably 150 x 2 at 2 ohms, but you're speakers are 4 ohms... so that'll only do like 90 or so x 2 at 4 ohms (check the manufacturer specs for 4 ohm stereo rating)... look for something in the 125 x 2 or 125 x 4 range for your momo 6 inch component sets... they'll be "happier" with the greater power.

1- head unit power / amp power -- it does not "stack"... if your amp says it'll do for example 50 x 2, and you're head unit does 25 x 2, you will NOT get 75 x 2 to your speakers... you'll just get the 50 x 2 that the amp puts out.

2- USUALLY, but not always, you'll want to face your subwoofers toward the back bumper... but get as much distance between the subs and the farthest rear portion of the car -- so pushyour sub box as far FORWARD in the trunk as u can and face the subs REAR. as far as "why" -- Well, bass is better "heard" when its reflected... until its reflected, you dont really hear it. So you've got to bounce it off the back of the trunk and reflect it forward.

3- any two voice coils can be wired in parrallel, whether they're on the same sub or not... so you can "parallel" one sub with dual voice coils .... or you can parallel two subs with single coils... two 4 ohm coils = 2 ohm load.

Systems

i see what your sayin about the momos but you think the kenwoods will be fine, i suppose. ill be back with more specific information later.

Systems

k rockfords site is up finally.... dodge your right about the amps. 75 watts*2 @ 4 ohms. the 500s amp will give me 125 like you said, but that will cost more . about the kenwoods, the site is only listing 220 watts "power handling". is this implying max or rms? and finally would 75 watts be enough for these, cause with all the tweets they tend to come through the momos. btw ive only listened to these speakers on the DEH-P8400MP pioneer, so im guessing its about 30 watts a channel, and they still dont sound too bad. so i guess....

PoweredByDodge

re kenwood 6x9's --- if they're the excelon variety, i wanna say they're around 100 - 150 rms. if they're the standard kfc models... probably 100. which is not bad, dude that's fine for rears... kenwood makes a good product, always has (cept those dang original series tornado subs... EEK! they sucked! haha)

re amp power --- why not be practical here... you dont need 125 x 4... you're going to want more power up front than in back... you'll want your fronts to be louder, clearer, more robust and "present" than your rears... your rears are to "fill" or "even off" the sound.

something like 75 to 85 x 2 for the rears would be fine. however, up front, i think you'll "tolerate" 75 x 2, but you wont be really pleased they way you probably would with 125 x 2... i'm gonna do some amp hunting... i'll post back again in about 15 minutes with some suggested amps in a price range that's cheap... keep in mind i'm a guy who bought a 70 dollar JBL amp used for his highs rears...lol. i'm a penny pincher if there ever was one.

PoweredByDodge

k... here we go...

for fronts - Pioneer GMX 972 - this is rated at 14.4 v whereas the fosgate stuff's rated at 13.8 -- this pioneer is rated 150 x 2 into 4 ohms at 14.4, so you can figure 135-140 at 13.8... which is what you're lookin for. its 180 bucks at crutchfield.com, and probablythe same at any retailer... if you shop ebay, its probably only 60% of that. only one problem, it does not have a built in high pass crossover, thats one of the reasons its only180 bucks... but you're pioneer dehp8400 has an electronic selectable high pass crossover built in to it... so you're ok because the deck will do that for you.

Pioneer makes a good solid product... while I would not use a pioneer to drive a high power subwoofer, I've considered them a very good "mid level" amp for powering highs -- in the same class as mtx / kicker / fosgate and the like... if anything, you may find the pioneer to be a cleaner (less thd) amp than the afore mentioned other brands.

for your rears... sticking with the pioneer... the pioneer GMX572 is rated 75 x 2 at 14.4 (figure 70 at 13.8). same goes for the lack of a high pass as above -- but agin, the deck will take care of it. price = 150

i think this is your best bet taking into account the idea of price and quality / performance... you're total bill for the two amps would be like 330 bucks, which is cheaper than just one fosgate 500s. even if you wanted the higher power 150 x 2 pioneer for both front and rear, that's still only 360 bucks while the single fosgate is 399.

i'm still droolin over what i just saw though... mtx's got a stud amp it looks -- 235 x 2 rms into 4 ohms and 950 x 1 bridged into 4 ohms.... *drool* -- i really wish their site was updated with detailed specs... i wanna see the 12.5 v rating on that thing... its got the same case as the 81000d... if its clean as hell i'll sell my mother and buy two, the 1.5% thd on the 81000d's irritates me, its audible.

PoweredByDodge

i'm diggin these new amps -- fosgate power 851x - 110 x 4 into 4 ohms... 600 bucks though...

mtx 1004 - 125 x 4 into 4 ohms -- 700 dollars! jesus!.

elocate

I'm sure this has been said in one post or another, but i am pretty lame when it comes to certain things, My question is re: what amp to get. I apologize if I get too wordy..

I am looking to better power my front & rear door speakers. the rears will be Polk/momo MM6's, the fronts are just plain polk, old dx's I think? I can always get another set of MM6's if everything has to match to sound best.

Is it possible to properly power all of these speakers with just one 4 channel amp. 150w x 4 maybe? From what I'm reading the polk/momo's are a bit on the power hungry side. Of course I have no idea of the ohms or anything, like I said, I'm pretty lame.

I already have 2 Momo subs in the back, so it's just the doors I thinking about? Any ideas? I would go as high as $500-600 if it was exactly what i needed...

PoweredByDodge

heya kimosabi...

why do you have teh DX in front and the momo in back? i mean, to be practical and save money... you should put the momo components in front and the DX in the rear, since you're going to put like 25-30% more power to yoru fronts than rears. that way you dont have to actually spend more money and buy another set of speakers... just "move" what you've got to get it to sound right.

anyway --- 125 -150 x 2 fronts .... 100 x 2 for rears should be fine... so yes, a single 4 channel that was 125 x 4 or better would do the job just fine. note -- all of yoru polk non-subwoofer speakers are 4 ohms.

amp suggestions...

--> Autotek Stealth XS-900.4 (110 x 4 -- $425.00 -- Soundomain.com)
--> Rockford Fosgate Power 851X (110 x 4 -- $600.00 -- Crutchfield.com)
--> MTX Thunder 1004 (125 x 4 -- $700.00 -- Crutchfield.com)
--> Two Directed 2400's (125 x 2 -- $320 x 2 = 640 -- theZeb.com)
--> Hifonics 125XIV (125 x 4 -- $700.00 -- theZeb.com)
--> Audiobahn A4125HCQ (125 x 4 -- $1,000.00 -- theZeb.com -- this is acutally a High Current amp... you'll notice the difference in quality and performance).


Remeber, you can also "beat the system" and just get two amps that are 125 - 150 x 2... or get two amps that are 4 channel amps ... that are like 50 x 4... when u bridge them they'll come out to 150 x 2 each. The thd is a little higher, but you probably wont notice it, unless you'd actually notice the difference in the Audiobahn HC versus the Autotek.

sntnsupermen131

i noticed a $575 difference that im not particulaly fond of for an amp of that size...
-Cody

elocate

Thanks for the reply PoweredByDodge...

I was going to replace my rear door polk dx's with the momo since they were actually closer to me sound wise. The front door speakers are down low, by my legs. I figured if I put them in the rear just slightly behind me, with no obstructions I would hear them better. I have a Camaro, so speaker locations are at a minimum.

And I wanted just one amp for all my door speakers is at all possible.

PoweredByDodge

ahh -- gotcha now -- well, ya its possible... lol. and if u're speakers are THAT close to you, you can get away with less power -- 90 - 100 x 4. hunt online... they're not that much $$.