Hey, So i have a older Alpine MRV-1507

Specs: The MRV-1507 is a two-channel amplifier with power ratings of 225 watts x 2 or 900 watts x 1 into 4-ohm loads and 450 watts x 2 into 2-ohm loads. Features include an internal crossover and subsonic filter, line level outputs, fan-forced cooling, and a low frequency EQ with full parametric operation.

Probably going to running 2 10's in a sealed box.

My question is, do I want to run it bridged for the 900x1 4 ohm load, or do the 450x2 at 2 ohms.

Hope that makes sense. Haven't done much car audio stuff in the last 5 years or so.

Thanks.

 

Just a bit of advice, I'm no expert. You could very easily do bridged. Get two dual 4 ohm woofers. That amp could possibly run 2 ohms bridged. I used to do it all the time back in the day when I was broke. As far as subs a good pair of 8s or 10s would do the trick. Don't rule out a single sub setup either. Although I would rather 2 vs 1, it's still possible to run a 1 sub setup and sound great. A lot of the times it's better to have too much power rather than not enough.

Example, I had two 10s rated for 1000w each. They were ran on a 3500wrms amp that was wired to .5 ohms. After impedance rise I may not have even seen rated power. With that being said, this is not a factor that people should really worry about unless competing, but it's good to know if wanting to determine the actual power the subs are receiving while playing.. I had the 10s in a bit smaller enclosure than they spec for, that was because i wanted a bit more cone control. Especially since I would be played above and below my tuning frequency. But they played amazing! I did a score on a term lab(149.2 decibels) at a respectable 35hz, and they never got hot and never smelled. Played them like dogs for over a year and a half with not one hiccup!

If I wouldn't of had enough power I would have likely pushed them into distortion too many times and killed the subs. It happens way to often with people who don't know what distortion is. Make sure your subs are matched with your amp. Sundown audio has a few good low end(entry level) lines. I lean toward their stuff a lot. Although i have never ran anything sundown, I hear people are very happen with the customer service and products.

Good luck

 

Dual voice coils in parallel ( + from the amp to + side of one voice coil to + of the otherside of the speaker then to the +'s of the second speaker... Then same on all the negs.... This will draw a 1ohm....

 

Yeah, but is the OP's amp stable at 1ohm? My memory says that no alpine V12 series amp was 1ohm stable. Seems they burned up or tripped.

Back in the day if you wanted 1ohm or less and stable, you picked up an Orion hcca and called it a day.

Sheesh, I feel old now....and way out of touch with car audio...
Sent from some string and a few tin cans.

 

Right! That's why I mentioned.... For dual coiled speakers... 1 speaker, dual voice coil to the amp bridged would be 2ohm.

But back to the question.. 450watts to a 10" speaker is plenty in my book.. I'd even turn the gain down to about 3/4 up......first off though, when you get the speaker look in what the 10's are rated at... But definitely, I think, run it in stereo (straight wire) instead of mono (bridged).. And I would use the built in crossover if you don't have an eq of some sort. But then If you want to bridge the amp for 2 10" speakers, they would have to be a single coil to run parallel off your amp in 2ohm

 

Why not run a DVC?

Run the amp bridged and then wire the speakers in series or series/parallel combo? Could end up at 2ohm driving amp at its max or 4ohm with margin of error?

Sent from some string and a few tin cans.

 

Thx for the replies guys. I was having trouble figuring out where to place the amp. I ended up buying a 10" JL TW3 and a small alpine 500w amp to power it. Making the box myself and going to mount it to the tailgate.

 

A better bounce (for bass sound waves) is to face the speakers toward the tailgate not towards you...

Unless your building some bandpass style box with ports

 

. I'm not saying this is wrong I'm just curious, why is this? Bass is supposedly non-directional. Why would facing it away from you improve bass? Especially once the top is off or if you have a soft top. I would guess all the sound waves would fire out the open back with nothing to bounce off of. Also how does a band pass differ in how you point it? Should the ports face toward or away from you? Thanks

 

the ideas is to get the woofer into a position will the reflections will be minimized. Sometimes it isn't possible or practical. So firing them towards the rear will, I theory, only cause a single reflection causing the least cancellation. The best arrangement would be the farthest point from the front listening position IN THE FRONT. second best, since it is bass and mostly non directional, the farthest position from the front listening position in the rear. If that isn't possible, then firing the woofer towards the rear will cause mostly just one near field (and more unified) first order reflection with only minimal phase cancellation. The rear tailgate idea would cause the least cancellation, but firing the subs toward the front doesn't allow the lower level distortion to be masked as easily. This location will produce the most bass, again in theory, but the distortion the woofer makes when driven last it's limits will be much more audible. The third choice, firing them to the rear, is often the better choice for sheer useable output. This configuration masks more harmonic distortion, and since the path length is essentially longer (the frequency has a longer distance from the position to the tailgate to the front) it can produce deeper wavelengths (lower frequencies are longer wavelengths) with the ability to hide distortion. Distortion is usually a higher frequency(much shorter wavelength) and during the reflection off the tailgate the chances of it canceling out is greater. It is still there. And the subs are still being damaged, but the useable output gained vs the slightly shorter speaker life is usually a better trade.

There is a reason Jeep positioned the factory sub into the corner of the back furthest from the driver. Longer path length. It wasn't the easiest spot. In fact it required several different part numbers and building it around the roll cage. But, it does help a underpowered, crappy sub sound it's best. The engineering behind the decision was solid. But it isn't a practical solution for a large sub. Nor a large enclosure. But for the Jeep it was the best solution. In fact, most car designers use a somewhat similar approach. Some, my girlfriends new Lexus, have the sub mounted into the far rear of the trunk next to the rear tire. On the passengers side. Longest practical wave length again.

Back to your idea? It will work, but like the spare tire mount issue, adding weight to a Jeep tailgate is a recipe for expensive hinge problems. The best idea, for a jeep with big subs, is to build an enclosure to fit behind the rear seat and fire it towards the rear. It even works semi ok with the top down.