Rx7Roadster

I have a Alpine Type R 10" sub that is 300W RMS at 4 ohm that I am adding to the bose system. It is the dual 2 ohm voice coil model. I do not know a lot about car audio and want to know what size amp is recommended. Should I get something that is 300 W rms or something bigger or smaller? Any advice would be appreciated. Thanks.

DreRX8

You should match it up with an amp with 300watts rms--you would be fine if the amp was rated at 200RMS.

Rx7Roadster

Would the JL Audio 250/1 work ok?

djgiron

The way you worded that is that you have 2 2ohm voice coils? If that is the case you need to get either a 2 channel amp that is 2 ohms stable, or a mono amp that is 1 ohm stable.

Rx7Roadster

You can wire the sub in series so that the amp will see 4 ohm resistance. The manual that came with the sub shows how to do that. The sub used to be hooked up to a 4 channel amp with 2 channels bridged. I am moving the sub from the rx7 convertible that I had it in into my rx8. I could resuse the amp but I would not be using 2 of the channels and it will only produce 150W of power. I know a little about electrical engineering and wiring from the classes I took in school. I am looking o ger a new amp for it and do not know that much about matching subs and amps which is why I asked the question. Thanks for the replys though.

belkjz

definetly recommend the jl amps that 250 will put out more than enough power it also has a good crossover 24db for running it off of high level inputs

djgiron

That is showing as 1.5 ohm stable, it may work, but if you burn it up they won't warranty it. It is designed to run 3 of their 6 ohm subs

belkjz

the amp has regulated power output he already said hes gonna wire it in series for a four ohm load the amps are meant to run anything you basically pick how much power you want and dont worry about lthe load you place on it

Butch Brown

JL Audio 250/1, I have one with a JL 8" sub and it works great. Fills in for the muddy bass with the Bose and turns it into a nice system. YOU MUST use a 1 channel sub amp with a 2 OHM sub multi channel amps are no good for less than 4 OHM, they overheat.

belkjz

by the way there six ohm subs are dual voice coil so you can run them at a four ohm load off a jl amp but the original reason for dual six ohm coils was to place a 1 ohm load on an amp with three subs

djgiron

Or you could just wire them up 4ohm like . . .

djgiron

wow this got active real quik haha, I am behind like only 4 posts . . . yeah your correct I was thinking 6/2=3 then 3/2=1.5 instead of 6/6=1, it is late over here on the otherside of he world And he posted his reply as I was typing my other reply so uh, yeah

forbidden

Wire the sub in series to make it seem as a single 4 ohm load to the amp. This is done by wiring one voice coils negative to the other voice coils positive. Use the two unused terminals, one from each coil to go to the outputs of the amp you choose.

For an amp any 2 channel amplifier that bridges to mono will work just fine. There is no need for a mono sub amp, matter of fact, it is probably a waste of money. Mono sub amps for the most part are designed to produce maximum output power as the impedence drops. In this case you are not dropping, thus a 2 channel amp is best suited to this application.

As far as power goes, you can underpower or overpower a sub all day long, provided you allow the sub to cool and do not send it a clipped signal (distortion). This is much more of a danger with an amp that is too small. An amp that is too big can always have it's gain kept at the minimum, thus it is a much safer bet. Find an amp that is rated at about 75w x 2 rms, this will bridge to 300w rms x 1 in mono. A little bigger would not hurt as well. Ensure that this power measurement is taken as close to the 12volt rating as possible.

lurch519

ok, the jl slash series amps will work 4 ohms, 2 ohms, 1.5 ohms, or anywhere between 1.5 and 4. doesnt matter. they will make their rated power any impedance in that range. as to an amp for that sub, i would reccomend the jl 500/1 because that sub can take way more than it is rated for (i know these things as i am a jl and alpine dealer) but i would actually recommend getting the dual 4 ohm sub, and running a kicker kx 400.1. finding an amp that is stable down to 1 ohm (both voicecoils wired in parallel on your sub) will be expensive, and finding one that makes good power at 4 ohms is really a waste cause it will be able to make more power at 2 ohms.

forbidden

As he already has the sub, finding an amp is the best way to go for him. He does not need an amp anywhere near the size nor ability of the JL 500/1. Granted it is a good amp, but it is not the amp for this application. Any sub can take more power than it is rated for, provided that it is allowed to cool as well. Again any 2 channel amp will work fine in this application and will definitely be a less expensive investment as well.