Amps for my system....finally...

audiobliss

Ok, I'm finally going to get an amp for my set-up. For those of you who've totally forgotten who I am (lol), I'll update ya on my system.

I'm running these Boston Acoustic RC520 component speakers. I'm also running a Pioneer Premier DEH-P860MP. Currently, I just have the mids installed, and I'm running them off the HU. I know that's definitely ideal..... but that's why I'm finally getting an amp. .....I hope....

So, anyways, I need advice on amps.....AGAIN....LOL

First, let's talk power. Boston Acoustics rates my components at 20-250 watts. So, should I want somewhere around 11-150 watts per mid-tweeter combo?

Next, arrangement. Should I be looking for a 2-channel amp and just run it through the Boston Acoustic crossovers? Or should I go with a 4-channel amp with x-over settings and just skip the Boston x-overs? I'm not going to want to do much tweaking, I don't think (perhaps turning down that bright tweeter!). So, would using the Boston x-overs serve my all right?

It's been so long since I've looked at this stuff, what kind of prices should I expect for what I'm looking for? In a walk-in car audio store?

Thanks! Absolutely any recommendations/advice on my system (or anything else, lol) is greatly appreciated!!!

neomagus00

nice choice on the speakers, i'll be interested to hear how they sound when properly amplified. i also like the HU - i have it, too .

Generally, manufacturers list ratings per channel, which means you want 250x2@4 ohms! you want the two channel because you said you don't want to do much tweaking; you can simply run the 2-channel into the provided xovers and be set. the auto-eq and TA with that HU will help immensely with that goal. (sidenote: you don't need the belt they want to sell you to hold the mic, any old belt will do). i will say that you should run the auto-eq program, but then customise the TA for yourself, to put the image where you want it (also, the auto TA setting messes with the balance a bit, which i don't like, but you may...).

All in all, a beefy 2-channel such as this rockford model should serve you very well.

P.S. the guy on your cardomain guestbook that says to get audiobahn subs? i implore you to ignore him as ferociously as possible, the equipment you already have shows you deserve better.

audiobliss

Ok, I think I need to clarify a few things.

First: I will definitely stay as far away from Audiobahn and equivalent junk as possible.

Second: Why do I want 250watts per channel? Boston's website lists the power handling from 20 to 150 watts per channel; I'm a little confused here.

Third: I also figured that all the settings I can set on my HU would help me with any tweaking; howver, you'll probably have to explain what everything on it does! So, it's great that you have the same HU!!

Fourth: I opinionateed about brands! lol I don't want any Rockford Fostgate gear. I'd look at Polk, JL Audio, Alpine, MTX, and Memphis Audio (maybe; might be the same as Rockford, though).

Fifth: I don't have nearly the budget that you obviously think I do!!! LOL There is a reason I bought some discontinued components off a sound board. The absolute most I'll be able to spend on an amp is ~$300, but I suspect it won't even be quite that much.



So, there's a bit more information. Bring on the advice!!

Thanks.

MacLeod

You dont need 250 watts per channel. If your speakers are rated at 150 then thats as high as you should go.

All of the amps you listed are very good but so is RF. You shouldnt discount them. They are way too popular for me but they are excellent equipment, especially the new Power line.

If youre wanting the most flexibility in tuning the output of your tweeters then bi-amping will be your best choice. If youre wanting a plug and play system then go 2 channel.

There isnt much mystery to choosing an amp. A watt is a watt. Youre buying for power, features and build quality. All of the amps you listed are top shelf goods although I doubt you can find one that will put out 150x2 for less than $300. If you want one of those youll have to cough up some more cash.

You could go with something like this Phoenix Gold 100x2 model. Even tho you dont like the brand, this Rockford Fosgate 100x2 would also be a good choice. There is also this Kicker 110x2 which would be my pick.

neomagus00

ah, i think you have a typo in your original post then. i thought that seemed high, but it was like, "cool!".

so yeah, seeing as nearly everyone is opinionated about brands, no biggie. kenwood, $219

That kenwood could serve you well. And i'd be glad to walk you through setting up the HU. i do wonder why you dislike RF, though?

audiobliss

hahahaha....I think I have some more clarifying to do....lol

Neo - When you said '250', I was like, "Whoa...did I say 250?!" So I went back to Boston's site and looked it up again...and lo and behold...it IS 20-250. Well, anyhoo, there's no way I can afford that much wattage. So, ~150 will hafta do it, I guess. Will that be ok? Also, what happened to that Crossfire you had in your post?! I'm sure I can't afford it....but I DO like to drool....lol. I guess I dislike RF for basically the same reason as Mac: popularity. Audiobahn, Infinity, Rockford Fosgate, JVC, JBL...they're all the 'cool' stuff....and while Inifinity and obviously RF make some good stuff, I just can't bring myself to use them. That'd be 'fitting in' with the bling-bling crowd too much.

I read this review on Carsound.com on Memphis Car Audio's MC300, and it seems to be just about exactly what I want. It's small (plus), powerful (plus), looks cool (nice), not a lot of features (hopefully cheap; nice), and has the fuses on the bottom (not nice!!). However, the article says that it accepts pre-out voltages from sources from 250mV to 5V; however, my Premier has 6V pre-outs; would that be a problem?

Something else about amp brands: I will be buying this from a particular store, so I'm limited to what they carry. (While this may not be the best thing to do when trying to put together a system, this is the way it's going to work; no need to try to get me to buy online; alas, it won't work.) If memory serves me right, the carry MTX, JL Audio, Alpine, Memphis, and some like Pioneer and Boston and what-not.


Thanks, and keep it all coming!!!

MacLeod

All of those are great. MTX is one of my alltime favorites as is JL Audio but out of those I think I would pick Alpine V12's.

exalted512

dude, put 250 watts to them...then you could make fun of all your friends and be like "my 6.5s handle as much power as your subs do" I do that to my brother all the time...he loves it.
-Cody

audiobliss

....blank look........my mids are 5.25 inchers........lol

Anyhoo, I can't afford that!! Absolute max budget here is going to be $300 (MAXIMUM!!) And that's at a walk-in store! So, I need to find something that's got enough power to make them sound good and not mess them up, but also won't break the bank.

Keep it coming!! Thanks!

exalted512

why do you want a walk in store?
this amp is $320...
http://www.onlinecarstereo.com/CarAudio/ProductDetail.aspx?ProductID=14801
dude, you know you want to...all the cool people are doing it...
-Cody

audiobliss

Yeah; you're right.....*sigh*...I want it.

However, as I stated earlier in this post, my amp is going to come from this particular store; unfortunately, that's not debatable. That puts limits on what I can get, and that's what I'm asking y'all to help me with: how to get something at least decent for what I want with-in a budget......at this store.

Thanks and keep it coming!!!

exalted512

and this particular store carries??
sorry if you already listed...im lazy
-Cody

neomagus00

wow, you are lazy...

of the ones you listed, i like JL, but that's probably out of your price league. i suppose you go in, say, "i want as much power as i can get for $300," and see what pops up. they're all good stuff, i think money is going to decide this one.

the crossfire was on www.acaraudio.com ; i erased it because it wasn't displaying properly. and the input sensitivity limits mean that you won't be able to turn the HU up all the way - you'll get to max power at about 5/6 max volume... on the plus side, gain is kept to a minimum, and thus, so is noise.

audiobliss

Originally posted by neomagus00
and the input sensitivity limits mean that you won't be able to turn the HU up all the way - you'll get to max power at about 5/6 max volume... on the plus side, gain is kept to a minimum, and thus, so is noise.

I assume this is answering my question about the Memphis amp and its limet of 250mV-5V for input? Assuming that's what you're talking about.........what if I turn the volume on my HU all the way up? Would that fry my amp? Of course, I wouldn't do that since I don't listen loud anyways.

Cody, I *think* they carry JL Audio, MTX, Memphis, Alpine, Boston, and I think Pioneer.


Thanks for all the advice so far! I guess now I just have to go in and look around. Bad thing is, I think he's only open Thursday, Friday, and Saturday. Now I have to wait a whole week. sigh

neomagus00

he's only open three days a week?? that's strange...

but yes, i was talking about the memphis, and you wouldn't blow your amp at full volume, but you would get significant distortion (past 5/6 your HU begins to distort, and past that the amp begins to clip - it'd get bad, fast). it will be WAY loud before that point.

audiobliss

Ok, I went to this CA store yesterday. Now I need some help thinking about all this clearly. He still has an Alpine MRV-T420 amp which is a 2-channel amp, putting out 170 watts into 2 channels each at 14.4V with .08% THD. That is one awesome amp. I'd LOVE to have it too, man! AND, he's selling it for $225; what a deal, right? The only bad thing is, I can't get something that's going to be visible. For one thing, Mom doesn't want to have to see it, and she doesnt' want it to compromise functionality. I'm also starting taking classes at a community college this summer, so I also want things to be tucked away nicely. In light of that, the audio store has said that we need to put the amp under the back bench seat (I'm about 97% sure an amp won't fit under the front seats unless it's really small); and there's only enough room for one amp under that bench seat.

So, here it is. This guy suggested that I go with a Memphis Studio series 75x4 amp. This way, when I get enough money for a sub, I can bridge the rear two channels to power the sub. This sounds like a cool idea, except I don't think that 75 watts is going to be enough for a tweeter and mid. However, if I got this 75x4 and bi-amped my components, that'd be about right, no? The bad thing is, this amp will probably cost me about $350. And that Alpine is only $225!!! Ahhhhh!!! lol



So, what do y'all think about that? Any ideas? Recommendations?



I just got done with talking to Cody on IM about making a box out of four sides (I'm actually serious, Mac!! LOL) to put right behind my bench seat and mount the amp in it to the floor. Then, I can make a top that'll hinge and cover all this up. Right now, I'm really hoping that Mom will go for this idea so I can get that AWESOME Alpine amp and have it hidden.


Any ideas, recommendations, comments are appreciated!!!

audiobliss

This is another idea of how to hide everything. This would be much harder to pull-off, I'm afraid, but it wouldn't cut down on my cargo space like the box plan would. Here's the 'everything's hidden' pic:

audiobliss

And here's the 'Man, look at my gear!' pic:

audiobliss

Man, this stinks. I just realized that the MRV-T420 makes that 170watts per channel at 2ohms!!! Arrggh...what a let down...LOL. But, 110watts @ 14.4V into 4ohms isn't bad. It makes 75watts with 12.0V. Would it be getting 12.0V or 14.4V most of the time? And that Memphis amp that's a 75x4, is it making that 75 at 14.4V or 12.0V?

Oh, well.

MacLeod

First off, that Alpine amp is going to make more power than its rated at so expect 110 watts per channel.

He has it so cheap cause its been discontinued. Alpine has redesigned its V12 line. Its still and flat out awesome amp tho.

You should get under your seat and take some measurements then go to Alpines website and look at that amps specs. Most amps arent over 2" tall so height shouldnt be a problem but length may be.

I personally dont care for Memphis Audio but they dont suck, theyre just not my favorite.

Hmmm....under the seat is the best stealth place to stick it. Refresh my memory as to what kind of car this is going in.

exalted512

jeep xj(like a laredo)
-Cody

audiobliss

'95 2-door Jeep Cherokee. Check the link in my sig.

exalted512

laredo, cherokee...same thing
-Cody

audiobliss

Nope. The Laredo is a special (trim) edition of the Cherokee. Meaning it's nicer.

exalted512

whatever...theyre the same thing...;)
-Cody

neomagus00

i'm not sure how you'd pull off the box with four sides, but i like that stealth install. the sub box would actually be nearly as easy to make as a regular box, assuming you're reasonably proficient at glassing (or are willing to spend the time to become so). the amp in the back seat might piss mom off too much, seeing as it involves a giant hole in the thing, but under the seat should be easy. mac's right, length should be the only issue, and to account for that you have to ensure ALL the amps you want will fit there. you could have a bit of the amp sticking out from under the seat into the rear, and build a little hideaway to cover it...

audiobliss

I'm not sure I can explain how the back seat is with words, but since I don't have a picture of it, I'll try. The floor goes up to meet the bottom of the back seat, meaning that the floor meets the back seat in the front and in the back. This means that there can be no amp sticking out, because the floor is in the way. Now, under the back seat the floor slopes back down and there is a cavity in there. On the left side (looking at it from the front of the car) there is a jack and such equipment for changing a tire, but the right side is pretty much just carpet. This leaves us with only about half the seat's length to work with, and not really all of that because of the floor's weird slopes and bumps and such. Under the seat, if it weren't for stealth, would really be a bad place to mount the amp. That's kind of why I like this idea of making a box in the back so much.

neo - The four sides explained: I would basically make a frame (a cube w/o the top and bottom), and mount a top with hinges to the back 'side.' It doesn't need a bottom because I can just mount the amps to the floor. This 'box' is just going to hide everything. Now for some questions of my own: Why would I need to be proficient with fiberglassing to make a sub box? It doesn't really matter anyway at this point, as a sub is still down the road a bit. I'm pretty sure I won't be making my own sub box, though.


So, maybe this gives y'all a little better idea of the space we're working with. It's a bit discouraging, but I'm actually really liking the idea of making a box in the back to cover up the amp. Good point about needing to have enough room for all my amps, neo.


Now, nobody answered my questions about voltages. I understand that at a higher voltage, the amp will make more watts. The Alpine will make 110watts by two channels at 14.4V into 4ohms. It only makes 75 by 2 at 12.0V into 4 ohms. How often would my car jump down to giving it only 12.0V? Wouldn't it be sending it 14.4V the vast majority of the time? Also, the Memphis Studio series 75x4 amp: is it making that 75 watts at 12.0V or 14.4V? If it's making it at 12.0V like the Alpine, then it's much more of an amp than the Alpine, 'cause it'd be making more than 75 at 14.4V.


Keep it all coming!!!
Thanks!

exalted512

youll probably be running at 13.8 most of the time.
-Cody

MacLeod

Dont worry about the voltages. Like Cody said youll be running around 13.5 volts all the time and with that amp being underrated as all high end amps are, youll get your 110. That Alpine is a better amp than the Memphis.

spwuinmk67

As far as mounting everything, I don't know if this is what your getting at or not, but why not make a flase floor? Build a frame that would take up the whole back, but high enough to mount your amps, crossovers, etc, then make a cover to go on top, leave maybe some vent holes on the sides, and have the back slope down a little for the trunk lid?

neomagus00

yeah, he's goin for a stealth box install... as long as there's no wires sticking out or anything, no one's gonna give it a second glance. and the reason i was confused was because i thought you were going to use it as a sub box, and i was wondering how you were going to seal the other two sides.

i spoke of glassing because to make a round enclosure (such as the one resembling a spare tire) you need glass, doing it out of wood would be needlessly difficult.

and a final note about wattage - you'll be making around 13.5-13.8 as you drive, but that falls to 12 when the car's off. it won't make a drastic difference in volume, but headroom will be affected - as long as you don't play it flat-out with the car off, no big deal. and it's rare to run at a full 14.4 volts in a real road car.