4 Channel Amp, 2 sets of speakers and a sub

glemay

Hey guys,

I'm just wondering, can I take a 4 channel amp and use the 2 front channels to power 4 4ohm speakers, and use the 2 back channels to power a sub?

Obviously i would need a 4 channel amplifer that would allow for different cut off for the front and back. Is there anything else I should be aware of if this can be done?

Is there anything you would recommend? I'm trying to do this cheap.

Thanks

MacLeod

This would work perfectly.

It would be rougly 50 watts for each of the 4 speakers and 200 watts to a single SVC 4 ohm sub.

glemay

Well that's a little more than I wanted to spend. But you are saying that what I want to do will work with a 4 channel amplifier, right? Is there anything specific that the amplifier has to have in order to be able to do this, or will any 4 channel amplifer work?

Thanks again,

Jerry

MacLeod

Make sure its stable to 2 ohms stereo and will work 3 way. Youll also want the rear channels to have a low pass filter, preferably variable.

glemay

Hey MacLeod,

"Will work 3 way"

Are you talking about the tri mode capability thing?
That would mean the amp would be a 2/3/4 channel amp right?

Thanks

MacLeod

Right.

Tri mode is actually referencing 2 channel amps. One that can run a pair of speakers AND be bridged mono to a sub.

But yeah, look for a 4 channel amp that is 4/3/2 channel AND is stable to 2 ohms stereo.

glemay

Alright, thats what I'm gonna do regarding the amplifier as soon as finals are over.

Now, for a sub, its gonna be in an open environment (boat). I have limited space, so i was thinking one 10 inch in a sealed box. Is this a good idea? How big will a sealed box have to be so that the 10 inch sub will be loud enough.

I dont think i will have room for a ported box. They are quite a bit bigger arent they?

Is there anything im forgeting to ask? lol

Thanks again,

Jerry

MacLeod

The size of the box wont make it louder necessarily. For that youll need more power and more cone area.

A 10 with 300 watts would be ok. That still wont be all that loud but itll be better than nothing.

exalted512

Size of the ported box depends on the sub. Different subs require different amounts of volume.
-Cody

glemay

ok, well I stopped by the boat and took a few measurement,

basically, the biggest box i can put where i want to put it is about 16"x16"x6"
give or take an inch or two

with this can you suggest some ideas, ported or sealed

thanks,

jerry

exalted512

budget?
-Cody

[Deleted User]

That's a .89 enclosure.

PoweredByDodge

Tri mode is not a 4/3/2 channel amp.

Any 4 channel (unless it's a complete heap) should be 2 ohm stable in stereo... so you can run 2 pair of speakers off the front channels and then bridge the rears to a single 4 ohm sub.

Tri mode is when you take a 2 channel amp (or the front or rear stage of a 4 channel) and use it as a split-phase transformer. the 'full sweep' feeds a subwoofer, while the left and right stereo speakers run off the center 'taps'. here's a diagram that makes it a lot easier to understand than me just saying it in words...

http://www.bcae1.com/trimodpd.htm

Note, in order to maintain a 2 ohm impedance across each channel, you must use 4 ohm speakers (the stereo speakers and the sub are all 4 ohm), and you must use passive crossovers that do not overlap constructively.

glemay

Ok, I realize that you guys need more info, so I'm gonna list what I've got right now, and what my goals are, lol.

Currently:

2 JBL 6.5 inch speakers (4ohm)
2 JBL 5.25 inch speakers (4 ohm)
1 Kenwood 2 channel amp (2x40 @ 4ohms, 2x60 @ 2ohms)
1 Pioneer ...4700 deck

Currently the Kenwood amp is running the 4 speakers, (2x60 @ 2ohms)

Now, as far as what I want:

Want to add a subwoofer to go in the space indicated (16x16x6)
Not sure if I should go ported or sealed,
Not sure if I should go 10 or 12,

As far as power,

Not sure if I should eliminate the 2 channel kenwood and run 1 4 channel amp

Maybe keep the 2 channel kenwood and get another amp?

Budget: would like to stay under $500 canadian, so call it $400 US give or take.

Is there a setup that would create less of a load on my battery?

This is going in a boat, so its an open environment, however I'm not too concerned about water since it will be in a dry place.

Alright, I think this makes things more clear,

Thanks

Gerry

PoweredByDodge

$230 US - here's a hifonics that'll do 55 x 4 to your highs + 300 x 1 to a sub (dual 4 ohm coil sub).

http://ikesound.com/product-product_id/4366


$155 US - or an autotek that's refurbished that'll do the same power

http://ikesound.com/product-product_id/6152

You can find a dual 4 ohm 10 or 12" sub that's 300 rms for around 50 to 100 bucks.

that'll bring you up to 255 or 330 US --- add in the price of the box (build it yoruself for 20 bucks dude) and you're all set and under 4 bills US.

Personally, I think either one of the above amps is your best bet... it'll give you the most features, and be hella cheap in the process.

glemay

PBD,

Yeah, I'm planning on building the box myself.

Should I be looking at a dual or single voice coil sub?

I forgot to mention, I only have an area about 16"x17" for the amp, so I can't go too big.


Thanks

G3n3R@1

as far as your battery goes i would just get another one and put it in the back of your car by your amp. get a cheap 40$ one and it beats the heck out of a capacitor.

PoweredByDodge

Glemay,

The dimensions on the Hifonics are 16 inches x 10.5 inches x 2.5 inches. I can't find any dimensions for the Autotek, but I'm sure if you call up Ike, they'll find out for ya.

For either of these amps, you would be looking for a -- DUAL 4 OHM VOICE COIL -- sub. When you hook the two coils up in parallel you'll have a single 2 ohm load to the amp's subwoofer channel... that way you get 300 watts to the sub instead of 150.

Here are some subwoofer suggestions...

$ 49 US -- Polk Audio DB104DVC -- http://www.cardomain.com/item/POLDB104DVC

$ 56 US -- Polk Audio DB124DVC -- http://www.cardomain.com/item/POLDB124DVC

I'd go with the 12 ... 56 bones is cheap as hell, and Cardomain (Sounddomain) is a factory authorized dealer. For the amps, Ike isn't an authorized dealer, but they offer a 1 year warranty (exchange or store credit) on everything they sell.

glemay

Hey,

Well, I've been looking around today. Went to one shop and the guy basically insulted me. I told him I was putting it in my boat and he was asking if this was a "carboat" or somthing,??? I was like "what??" and he said "I guess I lost you. What did you do, smoke a joint before you came in?" What an a hole.

Anyway, just for the sake of information, I tell him what I have and what I want to do. He comes back at me with this 5 channel amp. It was an Audison. So I ask him about the dimensions of the amplifier and his response "If you cant fit this in your boat, your doing something wrong". What the hell. Then I ask him how much, he says something like 800 CDN. I just looked at my buddy and there was no way I was gonna spend that.

So I ask him, "what other options have you got for me?". He says "This is the only way to go." So I ask about running a reasonably priced 4 channel at 2 ohms like we were talking about here, and he says "amps arent made to run at 2 ohms, power at 2 ohms will sound like ****."

Needless to say, I walked out after that. The guy was a total dick.

That feels better

Have any of you guys heard or Ultimate Sound, http://www.ultimate-sound.com/products_t2_amplifiers.html

I am thinking about the T2-2450, its the last one on the page, I can pick it up for like 100 bucks.

Thanks

MacLeod

$100? You get what you pay for. And you definitely dont want to be skimping on an amp for a boat!

That guy was a complete tool and I wouldnt even so much as drive by his shop ever again!

JL Audio makes a pretty solid 6 channel amp that usually runs $350'ish here stateside. Might want to check into that.

glemay

the amp is a demo, its regular $220 or something. Yeah, I'm a little leary on it.

If I buy stateside, are there going to be any cost to bring it over the border?

thanks

glemay

What about a Blaupunkt GTA4? Similar specs to the Ultimate Sound amp.

PoweredByDodge

Blaupunkt, Ultimate, and the like are all in the same category as Jensen and Kraco. Hate to bust your balls on this, but go name brand or don't bother. I'm not saying you have to spend 500 bucks, I mean hell - if you can find a used MTX or JL or Hifonics 5 channel for 50 dollars, then take it... it's not the cost of the item that matters, its the quality of the item itself.

Here's a phoenix gold with similar specs to the amps i showed you before -- its $150
http://cgi.ebay.com/PHOENIX-GOLD-R9-0-5-5-CHANNEL-900-WATT-AMP-NEW_W0QQitemZ290106640118QQihZ019QQcategoryZ39739QQrdZ1QQcmdZViewItem

PoweredByDodge

PS -- what amp are you currently using? We might eb able to figure out something that'll perform as good as a 5 channel, but not cost you as much (by utilizing the amp you already have).

glemay

Currently, I'm using a Kenwood KAC-5201, I think that's the model number.

It's rated at:

40 watts RMS x 2 @ 4 ohms
60 watts RMS x 2 @ 2 ohms
120 watts RMS x 1 @ 4 ohms

I was thinking about using this amplifier to power a sub, but I'm not sure if 120 watts RMS will be enough. I would have liked to keep using it for my 4 speakers, but there is no high pass filter. It only has a fixed 80hz low pass filter.

Now, I know you guys keep telling me to buy something good, I want to believe me. But I need to buy something from a canadian retailor, or at least from someone located in Canada. Shipping would end up costing me like 50 bucks, give or take, just to get it to my house. This is why I was looking at the Blaupunkt GTA4 Special and the Ultimate Sound T2-2450. The guy is located here in Ontario, and he will ship for free. I dont want to spend a lot of money on this project because its going in my boat. There will be moisture, humidity, blah blah, you know, lol. And plus, my boat is left out all summer, so I dont really have much I can do to keep theives away. If they steal a cheaper amp, I will be pissed non the less, but it wont hurt as much as having a real good one taken.

If you guys know of any online canadian retailers, let me know. There is not very many of them I dont think, but I could be wrong.

Thanks, I appreciate the help.

Jerry

Greg Peters

glemay wrote: »

If I buy stateside, are there going to be any cost to bring it over the border?

If you buy one in the US, you'll have to pay GST and Provincial sales tax upon declaring it at the border.

Jstas

Blaupunkt is a name brand. It's an arm of Bosch, the German electronics giant. They ain't junk by far but we don't get anything worth writing home about here in the States. All the good stuff gets sold in Europe or Asia. They have some nice stuff too.

glemay

Hey guys,

Well I've spoken to a few friends that have purchased this from online retailors in the states and things just arent sounding very good. From being charged 10% of the products value to over its value. So I think I am gonna eliminate the idea of buying online. There is just too much risk for me. I could end up spending more than I wanted too.

So, with that said and done, I think I'm just going to bite the bullet and buy from Futureshop or Best Buy. I'm gonna go check out the offerings at another specialty shop; hopefully the guys there are more useful and friendly. No way am I going back to that other place.

I was looking at a MTX TC4004 and a Kenwood KAC-8403. The are both priced the same. Here are the link

http://www.futureshop.ca/catalog/proddetail.asp?sku_id=0665000FS10074271&catid=11032&logon=&langid=EN
http://www.bestbuy.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0926INGFS10084902&catid=20104

Between the two, which would you guys consider to be the better buy?

Thanks, now back to dynamics...

Jerry

MacLeod

MTX, hands down!

MTX makes awesome amps. They make tons of power, far exceeding their ratings. Their build quality is also top notch.

PoweredByDodge

The MTX is likely your best bet.

It'll give you 100 x 2 at 2 ohms to the front (for your speakers -- so 50 watts per speaker), and 200 x 1 bridged at 4 ohms to the rear (for your sub).

If you go this route, then I suggest this subwoofer ---> http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10083856&catid=
Infinity Reference 1050 (or even try the 1250 --- 12" version). Single 4 ohm coil.

glemay

Well, that looks like the plan. Just another question. That MTX TC4004 amplifier won't put a really heavy load on my battery or charging system will it? I've got a deep cycle battery, not sure on what size, but its a pretty good size battery.

Thanks guys,

Jerry