Need some Help Amp... Simple for you Audiophiles

[rcknrolfender79]

Hey guys, just bought my first system today.. I bought the deck and door speakers new but the amp and subs are used. The head unit is a Pioneer DEH-150MP, the door speakers are Kicker KS600, the Subs are Alpine S 10", and the amp is a Crossfire BMF 250.M.

Now I bought the Amp and Subs together. Got a killer deal... 80 bucks for all 3 and the Subs are in boxes that will fit in my little truck (82 toyota pickup regular cab).

The subs and speakers both are 4 Ohm. The head unit requires 4-8 ohm speakers. I'm a complete noob when it comes to car audio so I have no idea how things should or can be hooked up. The Amp according to specs only has 1 4 ohm channel at 125 watts. And 1 2 ohm channel at 250 watts. Looking at specs here: Crossfire BMF250M (BMF 250M) 250W Monoblock Class A/B Amplifier

I'm wanting to run both my subs and door speakers off the amp for best sound. Is it possible with this amp? And of course I dont want to do anything thats a potential fire hazard. For instance can I run the subs off the 2 ohm 250 watt channel? And use the 4 ohm channel for the door speakers? To take advantage of the higher wattage... Or would that be no no?

Also this amp is a monoblock amp, if I run my door speakers out of it does that mean I will be hearing mono and not stereo? In other words if song is mixed to have the voice more to the left speakers and the music a bit more the right it wouldnt work that way with this amp?

If this amp wont work for me please suggest some good low budget amps I could get that would work for me. Or at least what I need to be looking for in an amp.

Click to read more...

 

[adulbrich 5,000+ posts]

Only run your sub off the amp

 

[rcknrolfender79]

Is there a reason? Are you not supposed to run door speakers off of an amp or is it because its a mono amp or what? Sorry I'm pretty clueless when it comes to car audio. And can I run the 4 ohm subs off the 2 ohm 250 watt channel or does it need to be off the 4 ohm channel?

 

[adulbrich 5,000+ posts]

Its a monoblock amp for subs. Because of the filters, the amp has a frequency response of 50-150hz.

There are lots of other bad things that would happen. You would ruin your speakers and probably your amp too, depending on how you wired everything.

I'm not going to get into it, but it would sound really bad. You could run your speakers off the head unit. However, most people would recommend getting another amp for them.

 

[Umbra]

No, you can't use a monoblock amp for the speakers because monoblock implies one channel. You'll need another two channel (or four - if you have four door speakers) amp to power your door speakers.

You can wire the door speakers directly to your head unit, as per the manual. They'll probably receive something like 15W RMS, not the optimistic 50W max described in the specsheet. It'll distort as you get louder, which is bad for the speakers and it'll sound like crap. It'll work fine provided you don't blast it, but aftermarket speakers really need an amp to shine.

If you want an amp for the speakers, you'll want to look for one that can provide from 6-65W RMS per channel (I'd shoot for closer to 60, personally) @ 4 ohms. Ohms is a measure of electrical resistance, as it goes down, the power output increases.

There are different Type S models. Check to see if they're single voil coil (SVC) or dual voice coil (DVC). SVC subs have two terminals (- +) , DVC subs have four (-+ -+). If you have a multimeter around, set it to ohms and measure one of the coils to confirm they're 4 ohms. Depending on your coil configuration, there's a bunch of different ways to wire up the subs.

The type S subs can take 500W RMS - each. That amp can put out 250W RMS @ 2 ohms, so really you'd be better off powering one at half power than two at a quarter power. The amp has one channel, you see two different power ratings that apply depending on what you wire to it. If the combined load it sees is 2 ohms you'll get 250 - at 4 ohms it's 125.

Mull these things over. The best thing you can do without spending any more is hook up your speakers to your HU and hook up one sub to the monoblock.

 

[rcknrolfender79]

So basically you guys are telling me I really need a better amp with 2 to 4 channels to get what I'm wanting correct? I basically got the amp for free and had plans of putting it up for trade plus cash from me for a better amp. I'll make sure I've got 4 ohm subs and find out if they are dvc of svc. And let you guys know.

 

[Umbra]

So basically you guys are telling me I really need a better amp with 2 to 4 channels to get what I'm wanting correct? I basically got the amp for free and had plans of putting it up for trade plus cash from me for a better amp. I'll make sure I've got 4 ohm subs and find out if they are dvc of svc. And let you guys know.

You'll want two amps, one monoblock for your subs and either a two or four channel for your speakers (depending on how many you have).

That's to keep it simple. There are also three and five channel amps where the odd channel outputs more power for a sub, but they're typically geared for allowing the addition of a small sub to add low end, not for powering bass cannons. There are also four channel amps that allow you to bridge the 3rd and 4th channels, again, that could be used for a sub, but it's not much.

Hit up Craigslist, see what you can find. You could probably find two solid used amps for under $200. Ask around here before pulling the trigger on anything, we'll lead you in the right direction.

 

[rcknrolfender79]

Ok Just opened both the subs up. It appears the guy I bought them from didnt know what they were. He told me they were 4 ohm. They are 2 ohm DVC...model number SWS-1023D.. Hope them being 2 ohm doesnt hurt me as my head unit says it needs 4-8 ohm speakers.. I'm guessing that rules out if you run them through an amp correct? Here is a link to them on Crutchfield...

Alpine SWS-1023D Type-S 10" subwoofer with dual 2-ohm voice coils at Crutchfield.com

And I've only got 2 door speakers.. one for left and one for the right. They are both 4 ohm speakers... Kicker KS600.

Also I'm not looking for bass cannons... lol well I dont think. I'm not really into extreme bass. I listen to rock, alt rock, classic rock, metal, indie (pretty much any rock you can think of) and a bit of dubstep. Mainly what I want is enough bottom end to really feel the crunch of the guitar and beating of the bass drum. But not so much to where its hard to sit in the car with it or hard to hear the rest of the music. I want a good clean sounding system with a nice bottom end. I went with 2 10's because I wanted an even sound on both sides of my truck and 10's because thats probably as big as I can get in my truck as its got very little room behind the seat. Would have went with 8's to be sure if I had found them first but I couldnt pass up 2 alpine 10's in the boxes I needed for $80.

Does any of this change anything or do I still need to look for another amp for the door speakers and keep the monoblock for the subs? Or should I look for a more powerful monoblock and a stereo amp for the speakers? Or should I look for a 4 channel set up for the subs and speakers both? I know its recommended to stay away from walmart junk but as they carry kicker stuff now I was curious.. they have a kicker amp... that looked like it would be good for the door speakers on rollback atm for $65 heres a link to it on their site Kicker DX125.2 2 x 62.5W Stereo Full-Range Amplifier - Walmart.com

Or is the kicker stuff at walmart just as bad as the rest?

Also do I need a 2 channel amp for the subs? A channel for each sub?

I just want the best sounding system I can get with what I've got and maybe spend a little more if needed. Dont want to skimp and hook the door speakers into the HU if its gonna make it sound worse than it could sound.

 

[adulbrich 5,000+ posts]

Kicker products are bad in general. Stay away from them.

Apparently they used to be good

 

[Umbra]

Ok Just opened both the subs up. It appears the guy I bought them from didnt know what they were. He told me they were 4 ohm. They are 2 ohm DVC...model number SWS-1023D.. Hope them being 2 ohm doesnt hurt me as my head unit says it needs 4-8 ohm speakers.. I'm guessing that rules out if you run them through an amp correct? Here is a link to them on Crutchfield...
Alpine SWS-1023D Type-S 10" subwoofer with dual 2-ohm voice coils at Crutchfield.com

And I've only got 2 door speakers.. one for left and one for the right. They are both 4 ohm speakers... Kicker KS600.

Also I'm not looking for bass cannons... lol well I dont think. I'm not really into extreme bass. I listen to rock, alt rock, classic rock, metal, indie (pretty much any rock you can think of) and a bit of dubstep. Mainly what I want is enough bottom end to really feel the crunch of the guitar and beating of the bass drum. But not so much to where its hard to sit in the car with it or hard to hear the rest of the music. I want a good clean sounding system with a nice bottom end. I went with 2 10's because I wanted an even sound on both sides of my truck and 10's because thats probably as big as I can get in my truck as its got very little room behind the seat. Would have went with 8's to be sure if I had found them first but I couldnt pass up 2 alpine 10's in the boxes I needed for $80.

Does any of this change anything or do I still need to look for another amp for the door speakers and keep the monoblock for the subs? Or should I look for a more powerful monoblock and a stereo amp for the speakers? Or should I look for a 4 channel set up for the subs and speakers both? I know its recommended to stay away from walmart junk but as they carry kicker stuff now I was curious.. they have a kicker amp... that looked like it would be good for the door speakers on rollback atm for $65 heres a link to it on their site Kicker DX125.2 2 x 62.5W Stereo Full-Range Amplifier - Walmart.com

Or is the kicker stuff at walmart just as bad as the rest?

Also do I need a 2 channel amp for the subs? A channel for each sub?

I just want the best sounding system I can get with what I've got and maybe spend a little more if needed. Dont want to skimp and hook the door speakers into the HU if its gonna make it sound worse than it could sound.

You're going to wire the HU to the amps via RCA, so the ohm requirement is a moot point, like you've deduced.

That's good to hear. Those smaller subs can handle 300W RMS each, so if you wire them to that sub you're giving them 250/600, which is underpowering them, definitely, but it's better than 250/1000.

Because they're 2 ohm DVC you can wire each sub to 4 or 1 ohm. You can then wire the pair to , 8, 2, 2, or .5 ohms. .5 is right out, you will blow up the amp. 8 is going to be really, really underpowering them, so 2 is definitely the sweet spot. Ideally you're going to want to run the pair at 2 ohms. This is how you do that:

You can also run one at 4 ohms if you're short on space, but it's obviously be less output.

Given what you're listening to, and because of your space constraints, you'll want a sealed box. Ported has its advantages, but not so much in those genres (excluding dubstep).

Kicker gets a bad rap, but their amps are actually pretty respectable. That amp does 30W RMS X 2 @ 4ohms. It's not the 65W your speakers could handle, but it's way better than nothing. I've had great luck with Craigslist, or you could try the Wanting to Buy (WTB) - Car Audio section. If you don't want to buy used or online that Kicker amp should be fine.

You don't need a two channel amp for more than two subs. It's mono, so any sub-bass in either the left or right channel will find its way to the subs. All the subs get wired to one channel. As a result, they divide the output amongst themselves.

I'd recommend installing what you have. You'll need a wiring harness to connect the HU to the car and a wiring kit to connect the amp to the HU, battery, and chassis.

Here's Knuconceptz 4 gauge KCA wire: KCA Complete 4 Gauge Amplifier Installation Kit - Merchandise. It's copper clad aluminum, so it's not as conductive as oxygen-free copper, but it's cheaper. It's their best priceerformance cable for your application, and it'll allow you to install a sub amp capable of fully powering those 10s. You could even slap a distro block on the end (which is like a fused splitter) so you can run one wire to the back, then two from the distro - one to each amp. You could manage both of those amps we talked about with a distro on the 4ga KCA, or run two wires. If you plan on upgrading to a powerful sub amp down the road and want to use a distro, buy the OFC (Kolossus) kit instead for future proofing.

That's enough for one response.

 

[rcknrolfender79]

thanks for the visual! Will come in handy for sure. And all of your advice. Been cruising craigslist looking at amps. Is Logic any good? Never heard of it.. Heres a link to what I found:

Logic soundlabs 2 chan 800w amp

Also how powerful of an amp should I be looking for for my subs? Dont want to underpower them or overpower either one. Just want to be able to get everything to its potential without going overboard.

Also found these: http://tulsa.craigslist.org/pts/4796942955.html

Is LA Sound any good?

http://tulsa.craigslist.org/ele/4804478590.html

I think the orion should be good for the door speakers correct? 50 watts @ 4 ohms to each door speaker.

 

[rcknrolfender79]

Well I just found out my HU has a built in MOSFET 50Wx4 Amp. Which I imagine will be plenty for the door speakers. So I just need a good Mono amp now for my subs.

 

[adulbrich 5,000+ posts]

Well I just found out my HU has a built in MOSFET 50Wx4 Amp. Which I imagine will be plenty for the door speakers. So I just need a good Mono amp now for my subs.

That's peak poower. Maybe 4x22 RMS

 

[snyderd758 10+ year member]

Kenwood KAC-5206 Performance Series 400W 2-Channel Amplifier for the front speakers. If you can find this in stock(check ebay)this is a great subwoofer amp especially for someone just starting out.JBL GTO-501EZ Monoblock GTO Series Class D Car Amplifier

Also in the meantime there is nothing wrong with running your door speakers off the deck and I would run both subs to wire the amp you have down to 2ohms. If your budget gets deeper post here and we can help you pick out the best bang for your buck.

 

[snyderd758 10+ year member]

which deck do you have?