Amp choosing and wiring help

[deepinya]

Ok I got a question about wht AMP to buy and how to wire it up. My original thread is HERE (http://www.polkaudio.com/forums/showthread.php?t=37227) in case you wanna read up on it.

Heres what I have planned out.

Eclipse cd8445 (already have this)
MMC6500 front
MMC690 rear
No sub for now but I MAYBE looking at (2) 8" ones cause space is important. I wanna see how it all sounds before deciding if I even want subs.


Now here are the questions
Do I want
400.4 to power my fronts and rears
400.4 (bi-amped)for my fronts 300.2 for my rears
300.2 for fronts 300.2 for rears
300.2 for fronts 400.4 for rears plus channel 3+4 bridged for my sub (if I choose)

Keep in mind that (2) 300.2 will cost the same as (1) 400.4. I really have no clue how loud 125 watts is. I can turn my stock system up all the way and I wish it was twice as loud/clear at times.

I know most of you will say forget the rear speakers but when I turn off my rears in my stock rig, it sounds as if Im missing something. WIll two 8" subs fill that void? Im not sure.

--------------------------------------------------------------------------

Ok now onto the wiring questions.

I see a lot of premade dual AMP kits online. Im probably gonna go that route but I dont know what gauge kit (4,8,2?) to look into for the system Im looking to build. For the actual speaker wire I will go to my local shop and grab some street wire.


If anyone has any tutorials for what I may need that would be great. Im looking to have this whole thing done before the march 5th weekend. As a thanks I will provide pics. :p

[deepinya]

A different question about the mmc6500. Should I put the tweeter in the stock spot next to the windshield or in the door panel where I see some people putting it? I can probably figure a way to put it in the mirror too.

thanks!

[MaC03]

See the thread I just posted if you decide on the 400.4. $264 at SD with coupon.

[MacLeod]

Get a single 400.4 and run all 4 speakers off of it.

Get a 4 guage wiring kit from your local shop which will be big enough if you decide to add an extra amp later.

Put the tweeters where they sound best. Get some 3M double side tape and try them in different locations and wherever they sound best, thats where you mount em.

[1996blackmax]

If you are not going to have passengers, foget the rear speakers. Put that money towards a sub. I would get the 400.4 to biamp the components.

[deepinya]

dammit blackmax we've gone over this already! :p

Ill make you a deal. If I get a sub and still feel like Im missing something YOU buy me some mmc690's! :)

[deepinya]

I see a lot of different AMP kits and the pricing depends on the brand.

I see
jl audio
stree wires
scoche

All these kits come with the same equipment (4g, fuses, etc) but price ranges drastically.

Is a wire a wire or will paying more money get me better sound?

[Greg Peters]

I wouldn't say "a wire is a wire".

Ever bought cheap jumper cables that you kept stored in the trunk, and when you finally uncoiled them to use, the insulation had degraded, cracked, and fell clean off?

For your main power wire from battery through the firewall, it pays to have some good insulation on there that will stand up to engine compartment heat, oil, flexing, etc. It pays to protect it with a wire loom and some harness tape, too.

Even if you put a loom over it in all in places where it matters most, power wire that is snaked all through the car to your amplifiers should ideally be able to stand up to all kinds of things- it would be a bitch to have a dead short somewhere (even if fused right near the battery, like it should be) because some insulation cracked over time and your bared wire contacted vehicle ground.

Pick a reputable brand, and protect the wire you run from any potential pinch points (think in terms of a collision). Run a fuse close to the max current draw for all down stream components, and keep in mind that most amplifiers draw enough current to cause a fire in the event of a dead short (however brief, before your fuse blows).

Pick the power kit you will be able to deal with best during install. Some kits have connections that require a specific crimper (or soldering), and some have set-screw type connections at the fuse block, distribution block etc. If you don't plan to solder or buy a large crimper, the set screw type of connections may cost a little more but save a bunch of work.

Unless you are dealing online, convince a sales person to crack open a package for you to look at (or check the bulk rolls in the install dept.). Quality varies brand to brand (and even within different lines from the same manufacturer). The kits do save you some money over buying all the pieces individually. You can usually buy whatever you need (over and above what is in the kit) from bulk stock for not much more.

[audiobliss]

Excellent advice above. Take it and fly with it. There is definitely a point of diminishing returns with wires (as there is with everything), but within reason the more you spend on wires, the better the quality, reliability, and performance. That goes with power/ground wire, speaker wire, and interconnects. Don't go overboard, but don't buy bottom of the rung, either.

I would suggest adding one more step to your incremental install. Just go with the HU, whichever main amp you decide you want, and the MMC6500s. Install that and listen to it without rear speakers and determine if it still sounds 'dead'. If it does, then add some MMC690s. If it doesn't, then welcome to increased detail, better imaging, and a clearer soundstage.

About the amp, I would personally choose the C400.4 to bi-amp the MMC6500s, but to be honest, the C300.2 would do a fine job, too.

[MacLeod]

A wire is a wire. Go to Walmart and buy one of their Scoshe wiring kits. You can pick up a 4 guage kit for like $20.

RCA's need to be a little fancier for their imporved noise rejection, resistance and connections but power wire is all the same.

[neomagus00]

addendum - car wire from a reputable manufacturer will all work well - 12 cent cable will not, house wiring cable will not... buy big on RCAs, it's worth it...

[audiobliss]

Eh, don't listen to Mac. He's still on the dark side when it comes to cables! :p

Streetwires and knukonceptz both make great quality cables/wires at good prices.

[MacLeod]

Well, I guess if I just dumped $500 on RCA's Id swear they sounded better too.

[audiobliss]

I'm not aware of anyone who has dumped $500 on RCA's, but...yeah...I'd be in love with them if they cost that much!! :p

[neomagus00]

i think that a truly objective mind can get past the price tag and actually judge a product based on its sound... but i still say all decent cables sound the same :p (tonally - not including induced noise!)

[1996blackmax]

dammit blackmax we've gone over this already! :p

Ill make you a deal. If I get a sub and still feel like Im missing something YOU buy me some mmc690's! :)


Guess I forgot :o . I would buy you those if you get me an ARC series sub :D .

[MacLeod]

Frank-Z over on the HA side said it best and its the motto I try to live by.

My ears = no difference
Your ears = not my problem

[1996blackmax]

That's a good one :D.

[audiobliss]

That's gotta be my second favorite quote.

[deepinya]

So Ill assume scoche is a no name company so stay away?

Who do you recommend for RCA cables? Ill want some shielded ones so they dont cause interference with the remote on line going back to the h/u?

[neomagus00]

actually, scoche isn't bad, go with them if you like...

generally stick with stinger or streetwires for RCAs... and fyi, who cares about the REM wire, the point of shielding is to prevent noise from getting IN to the cables, not OUT of them...

[deepinya]

I thought the remote line carries power to the AMP so you want shielded RCA cables since I will be running them on the same side of the car.

I think I just worded it wrong in my post. :)

[exalted512]

get everything you need from www.knukonceptz.com and call it a day.
-Cody

[audiobliss]

^^ That's it. Great prices. Even better products. They have the fuses, distributor blocks, power/ground wire, and RCA's. You'll be set.

[neomagus00]

I thought the remote line carries power to the AMP so you want shielded RCA cables since I will be running them on the same side of the car.

I think I just worded it wrong in my post. :)
nonono... the remote line simply carries a very small signal that tells the amp to turn itself on... it is the 'remote turn-on lead' to be exact... if the signal there gets messed up, it doesn't matter - as long as there's some sort of current running in the REM wire, the amp will be on...

the power cable carries power to the amp from the battery, and the ground cable allows it to flow back out and into the chassis of the car (where you allow the stock wiring to carry it back to the battery, completing the circuit)...

you want shielded RCAs because the automotive environment is horrifically noisy over a lot of the electromagnetic spectrum... noise is bad for quality sound... shielding removes noise... therefore, shielding is good for sound...

[deepinya]

ok I see now

thanks neo.

[neomagus00]

any time :p

[deepinya]

Ive decided to get (1)c400.4 and bi-amp the mmc6500. I will hold off on rears/sub for now just so I can at least hear this bi-amping craze! Only thing that sucks is cardomain says 5-7 days until the c400 is shipped! :o

So do I need a 4-channel RCA or 2-channel RCA for bi-amping? I was gonna go with the Klarity cable but the Krystal Kable from knuconceptz are pretty well shielded. no objections?

This DIY stuff is a lot of prep work.

Tell me when Im a pain in your ass. hehe

[neomagus00]

no, my ass is currently fine...

if your HU has 2 sets of preouts (front and rear) use a 4-channel RCA, and use both preouts... if you only have one preout available, use a 2-channel RCA, and a pair of splitters...

[audiobliss]

Yeah, use a 4-channel RCA (or two 2-channel RCA's...shouldn't be a difference), but if your HU doesn't have three sets of preouts, then get another HU! A system as fine as you're building deserves a nicer HU than one that only has two sets of preouts.

EDIT - I just noticed that you already said in your first post that you already have an Eclipse 8445, so you should be golden. Eclipse HU's are great.

Glad you're willing to try the fronts first. Let us know when your stuff shows up and your doorstep! And don't hesitate to ask questions! Even if I don't know the answer, I can at least post that I don't know, thus giving me a +1 on my post count! :D

[MacLeod]

We need a filter on here for bliss. Something that wont let the post thru if there is nothing of value in it. :p

Try Crutchfield as well. Theyre a fully authorized Polk retailer and may can ship the amp out faster.

[exalted512]

We need a filter on here for bliss. Something that wont let the post thru if there is nothing of value in it. :p

Try Crutchfield as well. Theyre a fully authorized Polk retailer and may can ship the amp out faster.
geeze...if you do that why not just ban him? he wont be able to post...
-Cody

[audiobliss]

geeze...if you do that why not just ban him? he wont be able to post...
-Cody

:eek: :eek: :mad: :( :o :mad: :mad: :D

We need a filter on here for bliss. Something that wont let the post thru if there is nothing of value in it.

Well, my last post was informative and helpful, no? :D

[MacLeod]

*****************


Alright! Justin came thru with that audiobliss filter!

[deepinya]

lol poor bliss.

So I just thought of something. If I eventually get rear speakers and a 2-channel amp to power them, would I split the two rear channel RCA to go into both my 400.4 and 300.2?

Why I ask this? I do not feel like taking my car apart to undo my fronts.

Since I will be bi-amping I dont have to mount the mmc crossover correct? I will be able to tweak straight from the AMP and my h/u?

thanks for all the help so far! ...even you bliss!! :p

[audiobliss]

thanks for all the help so far! ...even you bliss!! :p
Haha! Thanks! :D


If you use your HU's crossover, then you won't be able to bi-amp if you add rear speakers. The thing is, you're going to be using your rear speaker preouts as a second set of preouts for the front. Then you can use the crossovers and such in the HU to set the HP and LP for each driver. If you add rear speakers, you'll have to use your rear speaker outputs to give your rear speakers a signal, meaning you can no longer use them with your front speakers. No need to fear though, you can still biamp. You'll just need to use a y-adapter on the one set of front speaker preouts to split it into a total of 4 RCAs to go to the amp just like would have already had. However, the difference here is that you will no longer be able to use the crossover in your HU, because the rear speaker preouts are being used for the rear speakers. So, you would need to use the amp's crossover or an external crossover.

IIRC, the C400.4 has a very nice crossover, so I would probably just set it up using the amp's crossover instead of the HU's the start with anyway. But maybe you'd prefer to use the HU's, and then switch over if you decide to add rear speakers later.

Hope that made sense.

Oh, and if that stupid filter thing comes on and bleeps out my post, just lemme know...I'll PM it to ya....:p

[deepinya]

bottom line can I ditch the passive x-over or is this not a good idea?

[audiobliss]

Yes. If you decide to biamp the SR6500 with a C400.4, you are not going to use the passive crossovers that came witht he SR56500. You will instead wire the individual drivers to the amp just like you regularly would (as if they were full range speakers), but you will (or ruin the SR6500) set the crossover on the C400.4. I'd suggest setting it how the passive crossovers are set for a starting point. Then you can play around with different settings to find which you like the most.

If you're not going to biamp them and instead power them with a C300.2 (or with just the front channels of a C400.4), then you would still use the passive crossovers that are included with the SR6500.

As I say this, I remember that the passive crossovers for the SR6500 have two power inputs per side, so you can biamp them and use the passive crossover. However, you would not have any flexibility with tuning them.

So, if you're getting a C400.4 and are going to biamp them, I'd just forego the passive crossover and use the crossover settings on the amp (or maybe even on your HU - that's another thing to play with).

[neomagus00]

IF you biamp AND you still use the passive xover, you lose tuning flexibility insofar as you can't change xover points or slopes - not necessarily a bad thing, because those points and slopes are chosen for good reasons... you do still retain the ability to tweak the tweeter's output to just where you want it, which is generally why you bi-amp in the first place...

[audiobliss]

You mean that if you do biamp with the passive crossover, you can still control the tweeter attenuation? But not to as great a degree as you could by using the HU and/or amp crossover, right? Aren't there just three different settings on the passive crossover?

[MacLeod]

If you bi-amp and use the passive crossover you can attenuate the tweeters output by both adjusting the gainst for the tweeters channels and using the 3 way (-3, -1.5, 0, +1.5 db) attenuator on the crossover itself.

I kinda recommend using the passive as its been designed to get the most out of the SR's AND you get that nifty tweeter protection light bulb.

[deepinya]

Yeah but Im getting the mmc6500's!

[audiobliss]

Oh...oops. My bad. Then scratch the crossover and use the amp's/HU's crossover.

[MacLeod]

Yeah but Im getting the mmc6500's!

Well then everything I said stands except now its a 0,-3, -6 db attenuator.

[audiobliss]

And, I'm pretty sure the MMC6500 crossover is not biampable. So that would mean you have to use the amp's/HU's crossover.

[deepinya]

Yeah if you read the Polk page on the c400.4 it says the amp is made to work in conjunction with the mmc series (bi-amping).