Looking for amp opinions...again...

audiobliss

Ok, now that I've had a job for a while and have some money set aside, I've decided that I want to go ahead and get an amp for my system. Considering size limitations and prices (I'm fairly confident I can get some pretty good deals on Memphis), I'm pretty sure I'm going to go with Memphis Car Audio. I know they're not the best, but they're not bad and they're sure better than what I've been using!!

So, here's the deal. I've done just a little bit of research today on the net. Since I haven't actually talked the store here in town, I don't know prices and thus don't know exactly where to head. However, I have narrowed it down to a few choices.

First off, should I go with a 2-channel amp (about 100 - 150 wpc) to go to my crossovers for my components? Or should I go with a 4-channel amp so I can bypass my crossovers and use the one that's (hopefully) on my amp? Or should I just go ahead and spend some more dough now to get a 5-channel amp for when I get a sub? Or would just the front two channels of a 4-channel amp be enough for my components while I bridge the rear two for my sub? Or a 4-channel amp and then a separate sub amp later on down the road?

One thing I've decided today: Despite what some people have told me, I want a lot of power going to my components. I want about 120 wpc if I use the crossovers (2-channel) or about 55 wpc if I bi-amp (4-channel amp). Now, if I go with a 4-channel amp and bridge the rear two for my sub (whenever that may be), I'll be left with 55 watts per crossover. I don't want that. This is why I'm suddenly drawn to the 5-channel stuff. 55wpc to bi-amp and still 200+ watts for a sub.

ANY suggestions you have about my scenario and what kind of amp to use and so forth would be extremely appreciated. I'm actually meaning to move on and get this done sometime before the year is out.



Here's some of what I found:

16-MCA300. 150 watts x 2 channels @ 4 ohms.

16-MCA2004. 50x4@4. Here I get to biamp, but I want more power.

16-MCA3004. 75x4@4. Now here's the power!

16-MCH600. 55x4@4 and 400x1@1. Now I'm giving up some power over the previous amp, but I'm also gaining that 5th channel for my sub while not giving up my ability to biamp. I wonder what the 5th channel will do into 2 ohms, as that's what most subs are, right? Or are they 4ohms like the speakers? If they are...that sure isn't going to be a lot of power to it. Though, I'll only want a single 10".


So, what do you guys think? I've also thought about doing something like the 16-MCA3004 (75x4), and then getting a separate sub amp whenever I get a sub and stick it under the other seat. That way I could biamp with lots o' power and have a sub (prob the best scenario, in my mind). However, I don't know how the money will work out that way.

I guess right now I'm just waiting 'til I can talk to the guy and find out what prices are. However, I'd appreciate any info/suggestions/comments/guidance you wanna throw at me.

Thanks!
audiobliss

Siegel1719

Well most on here will recommend to biamp. So you could go with the 4 ch amp for the components and then a seperate amp for the sub. Or you can go with the 5 ch and biamp the fronts and get a DVC 4 ohm sub and that will drop your ohm load down to 2 ohms. Or even go with a DVC 2 ohm sub and you can get that 1 ohm load. All depends on how much you wanna spend and space and all that good stuff. But ive also heard bad things about 5 ch amps in general. Just about power output and system noise. But it was just in general.

Jeremy

audiobliss

Thanks for your input, Jeremy. I don't fully understand DVC subs and what you can do with them, but from what you're saying it seems that I can use DVC sub (like the Polk MOMO MM2104DVC) and wire it so as to get a 2ohm load? That'd be cool, as my sub amp wouldn't have to be as powerful that way.

Also, I've run across www.sonicelectronix.com. I don't know if they're authorized or not, but the have Memphis stuff, so I've been looking at their prices.

exalted512

dvc subs just allow for more wiring options. Think of it as two seperate subs. You have a dvc 4 ohm sub. Think of it as 2 4 ohm subs. You can wire 2 4 ohm subs in parallel to get a 2 ohm load or wire it in series to get an 8 ohm load.

Now since you want 2 subs, think of it as 4 4 ohm subs. If you parallel each pair together you get 2 ohms per pair. Now youve basically made 2 2 ohm subs. Wire those in parallel get a 1 ohm load, wire in series and a 4 ohm load
-Cody

audiobliss

exalted512 wrote:

Now since you want 2 subs

But I want one 10"!!




...and what about advice on the amps.......:D

EDIT - Oooh, oooh, oooh......2800!!! Did any firworks go off? What happened? Did I miss it?

MacLeod

Biamping is the most versitile way to run your system however straight wiring is absolutely fine. Its easier, cheaper and more practical to install. The ONLY difference is you lose some flexibility in tuning the tweeters.

Memphis aint the greatest stuff in the world but their amps are pretty good so dont sweat going with them, youll be fine.

The easiest way would be to go with the 2 channel now and then when you decide on the sub you want then you can decide on the amp you want to power it.

audiobliss

Note: For right now I'm going with prices off www.sonicelectronix.com until I can get prices from the store.

If I go with the 2-channel (16-MCA300) now, that'd be $250. Then when I get a sub amp (16-MCD500), that'd be $250. So right there's $500. I could just go with the 5-channel amp (16-MCH600) now for $390. Of course, I'd be going from 75 watts per front corner to 55 watts, but considering I'd still be able to bi-amp and still only have one amp, I think (am not sure) it'd be worth it.

However, I've really convinced myself that I want to go with the 75x4 (16-MCA3004) and then a sub amp. That way I get plenty of power, bi-amping ability and a sub later. That'd be $550, but I think (am not sure) it'd be worth it. That's only $50 more than the 2-channel and a sub amp.

Any more advice is welcome!

audiobliss

exalted512

i like the memphis m-class amps. Talk about compact, those things are tiny and can put out a lot of power!
-Cody

MacLeod

One thing you should be aware of. Memphis are competition level amps which means they are going to be underrated by a good bit. Id wager that 75x4 is actually making 100+ per channel. The 50x4 might be a better choice. Hell Im running a Crossfire 50x4 and its waaaaaay more amp than my SR's can handle.

audiobliss

^ That's what I've been thinking today. I talked to a kid at my community college (someone else my age who actually (seems) to know about CA!! Yay!!), and he said it'd be way too much. I also talked to a guy who used to work at a CA store (the one I'm going to buy from), and he also said it'd be too much.

I actually figured it would be. I just thought that it was only $50 more than the 50x4, I'd be able to use the gains to turn it down (thus extending its life), and it'd be more versatile in future applications.

However, I just went by the store's new location and talked to the owner. He seemed to think that 75x4 wouldn't be too much. BUT he said I'd need an external crossover since the crossovers that came with my speakers won't hanle bi-amping. I've been thinking that my HU would do all the crossover stuff, but he said it wouldn't. Now I'm stumped. Does anybody know if my HU will actually do the crossover stuff? I really thought it would..

If my HU won't do it....and since the external crossover (he said) will run about $120, I guess I'll just go with a 2-channel (the 16-MCA300: 150x2). That's kind of disappointing; I was looking forward to bi-amping. Oh well, a good 2-channel amp would still do really well for me.

Cody - Yeah, they're small! That's mainly why I'm looking at them. And yeah, I'm just looking at the MClass.


Mac - Good point. Perhaps less power would be ok.



Oh, and sorry it took so long to reply; we had a storm yesterday and so we lost our internet connection until earlier today.

audiobliss

Oh, do y'all know if Memphis MClass series amps come with birthsheets? If they do, I might could get the guy to look at them so I know how much power I'd be getting, so I might could back down to less power if it'd work.

Thanks!
audiobliss

exalted512

i can look tomorrow at work for you if i remember. We carry Memphis. Dont trust everyone that works at a shop. Our sales guy doesnt know all too much about a lot of stuff, neither did our old installer.
-Cody

MacLeod

You dont need an external crossover, this head is just trying to sell you something else. A midrange speaker is plenty capable of running full range and its natural roll off isnt going to be that much higher than its crossover point. Ive ran my MMC690's and MM6's biamped and they only have a single input crossover.

Run the tweet thru the crossover and the mid full range (80 Hz and up). If its too much you can always turn the treble down on the h/u which will take it out of the mid and then turn the tweeters gain up and there ya go. Thats exactly how I had my MM6's tuned.

audiobliss

How would I turn the tweeters gain up independently from the HU? Where whould I do that? To be honest, I'm not at all fond of running my mids full-range. Maybe if I had some Polks or something, but I've just got some old cheap Boston Acoustics, remember.

Cody - Whether you're talking about checking birthsheets, crossovers, or both , it sounds great! Whatever you can come up with!

I would personally put at least some stock into what this guy says, as he's (businiess) 'friends' with my dad and he's been doing car audio sales and installations for over 15 years now.

Anyhoo, if he could cut me some slack on the price of the active crossover...tell me some about them? What exaclty what do they do/are they good/do they really help/at least it'd be cool, right?

Thanks!!
audiobliss

exalted512

active crossovers are good when you want better tuning. If hes been doing it for 15 years then its a safe bet he knows what hes talking about. I was talking about checking on the mclass amps. i mustve skipped over the crossover part...
-Cody

audiobliss

I'll hafta look into some active crossovers, 'cause if they really are a nice thing to have and would let me easily tune (I'm sure I'm horrible at it...but it'd help me learn!), I might seriously consider them. What are some good brands and what are some things I should look for in an active crossover? Could you briefly explain what one is and why it is referred to as 'active'? Does your crossover have to be matched with wattage, or does that pretty much have no effect on the system?

Any info appreciated...am wanting to learn as much as I can...'cause I wanna do it right...just not spend too much unnecessary money...:p
audiobliss

audiobliss

I have no idea how much this would cost, but would an active crossover like this be what I'm looking for? (Would be nice to be able to stick with all Memphis stuff.)

http://memphiscaraudio.com/products/details.asp?id=73

I'm not sure exactly what he said or why ('cause the phone rang and I was short on time), but the guy at the store said something about I'd need a 3-way crossover; why's that?

Thanks!!
audiobliss

exalted512

probably for mid/tweeter and sub. you only need the 2 way. I can tell you what cost is on the memphis...again, thats if i remember to do it. We usually charge cost x 1.667, then add like $20 bucks. But itd give you an edge is getting a deal
-Cody

audiobliss

Thanks Cody. I appreciate the effort (assuming you remember...:p).

audiobliss

Is there anywhere in particular that'd be a good place for me to read about active vs. passive so I can learn exactly what they do and if it's worth the extra price?

Thanks!
audiobliss

audiobliss

Ok, I just got done looking at the specs on my HU on www.pioneerelectronics.com. If you go to my HU and then click on specifications and scroll down about half-way down the page, you see a feature called 'Pro mode'. If you rest your cursor over 'Pro mode' a little box pops up and says "PRO mode allows a 3-way configuration High/Mid/Sub rather than the typical Front/Rear/Sub. This is ideal for advanced systems that are biamplifying the front component speakers for improved sound quality and performance, and not using rear speakers."

Doesn't that sound like what I'm wanting to do? And so doesn't it sound like I could use the 16-MCA3004 (4-channel amp) to bi-amp my components and then use my HU as an 'active crossover' of sorts? Without spending an extra $120 on an active crossover? I'll hafta dig out my manual later today and read what it says about it, but it certainly seems to me that this should work.

If that would work, would an external active crossover provide better performance than the one in my HU? Would it be worth the extra price?

Thanks!!
audiobliss

MacLeod

For $120, the crossover network in your h/u will be just as good. Now if youre talking a $1000 Audiocontrol unit then that would be the better preformer.

Id go with the h/u's.

exalted512

AudioControl DQX...drool
-Cody

audiobliss

I'm having a hard time deciding between bridging the amp and using the passive crossover, bi-amping and using my HU's crossovers, or going with an active crossover and bi-amping.

Hmm. Decisions, decisions. I guess prices will help decide to a certain extent.

Any more comments on anything I've mentioned or something I should think about, please post! I wanna hear it all! lol

Thanks!
audiobliss

exalted512

youll have to buy a couple of short rcas to run the crossover. what i would do is get the amp and use the passives. You can always use the option that your head unit uses. Get the active crossover last, its something you can do without
-Cody

MacLeod

For what its worth I do not like the idea of bridging a 4 channel amp at all unless its for subs. I just dont like the idea that the amp Im using to reporduce the ever important mids and highs is working at 100%. Bi-amp beyotch!!!

audiobliss

I agree with ya, Mac. I've just recently realized my amp would be working a lot harder; I don't want that. Thus, I'll either bi-amp with my HU or an external crossover. I'm still not sure on which one.

exalted512

cost for the 2-way is $35.70, we would charge $89, but could go down to $59 if we really liked you, $69 would be the minimum we would go for someone we didnt really know
-Cody

audiobliss

Hehe.
1) Do you like me?
2) Do you have a location in North Carolina?
3) If no then how does this benefit me?



But honestly, I can't believe cost is only $35.70; at that rate I could build a killer system for cheap!! I soooooo want a job at a store.....*sigh*....

audiobliss

Since my Adobe Acrobat Reader ain't working (arrgh), Mac was nice enough to read the specs Memphis has on their 75x4 and 50x4 amps for me. Thanks Mac! Really helped out!

So, here's what I learned. The 16-MCA3004 is 7.68"x2.4"x18.5". The 16-MCA2004 is 7.68"x2.4"x14.1875". The space I have under my seat is 10"x4"x18.5". So, I think the 75x4 will fit, though it'll be a close call.

'Nother thing. The Memphis amps will accept up to 5V inputs. My Premier HU has 6.5V pre-outs. Does this mean I'm sunk? I sure hope not...

Thanks!
audiobliss

MacLeod

Shouldnt be. The gain's singular purpose is to match input levels with the head unit.