JVC SHD 55
Alpine 10" Type R DVC Subs (2)
Alpine MRD M300 Amp

The subs do not pound at all.

The wiring on the subs is all correct and everything (audio shop checked it)

Would the head-unit be the weakest link and not provide enough power to the amp and subs?

 

FIrst off, the head unit will not send any power to the amp, except thru the remote turn on lead. Also in my opinion, I think you will need a bit more than 300 watts to get them to thump. I have installed many of the Alpine Subs of any level, and believe me they will hit. Try using a Class D Mono amp ran in parallel to get a 2ohm load. Trust me they will cause some pain.

Also why did you get such a low end head unit to put with the Alpine subs and amp? Just curiuos. I would have spent the extra few bucks and got an Alpine Head unit to match the rest of your set up.

 

you should have done the 500 instead of the 300, other than that those subs should slam. our demo car at work has 2 300's to a single 12"type r in a ported box and it sounds really good.

 

What size is the box? Common chamber or seperate?

 

The amp sounded fine with those subs when we tested them in the store.

I just found out the head unit only has 2V pre-outs, will that be the culprit?

When I mean don't pound, I really mean it. You can barely hear the subs even when cranked up.

Oh don't ask me why we are using that JVC deck, this is my friends deck that he already had in the car.


Modified by Understeer at 1:29 PM 4/21/2003

 

they're right, they should pound...try a better amp with more wattage, other factors come into play too, box type, air space in the box, ways the speakers are facing...are they wired right? since their DVC...try wiring them parallel, it'll bring down the ohms a little more...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by zeROTWO_CG6 &raquo;</TD></TR><TR><TD CLASS="quote">they're right, they should pound...try a better amp with more wattage, other factors come into play too, box type, air space in the box, ways the speakers are facing...are they wired right? since their DVC...try wiring them parallel, it'll bring down the ohms a little more...</TD></TR></TABLE>

150w a piece isn't much, especially with an 85dB sensitivity and a small box. Once again, how big is it?

 

ah,

When I mean "don't pound" I mean you can't even hear the subs put out any base.

The box, well it is just a pre-fabricated sealed box.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Understeer &raquo;</TD></TR><TR><TD CLASS="quote">just a pre-fabricated sealed box.</TD></TR></TABLE>

I bet that that doesn't help. Have you ever seen the inside? Did they use silicone or anything to seal the seams on the box? Are your gains set correctly? What about your crossover? Is it set to highpass? Are they out of phase?

 

dude alpine amps are SQ not SPL. Switch it over to an MTX Thunder6500D and you'll really hit.

 

If you have dual voice coil Alpine Type-R subs, each voice coil is 4 ohms. You can wire the two all in parallel for a 1 ohm load, which the MDRM300 isn't stable to (I think) or do combination series parallel/series wiring for a 4 ohm load overall. This amp has an unreagulated power supply, so I think you are only seeing 150 watts RMS to the subs and only 75 to each sub. This amp needs a 2 ohm load to get the 300 watts rms out of it. You may want to consider asking the shop of they are willing to swap out your DVC versions for single 4 ohm versions so your amp can put out the most amount of power it can.

Are the speakers' wired correctly? Are they in phase with each other? Is the enclosure properly built without any airleaks near the baffle? Is the amp setup correctly, did you play around with the gains and the xo points? These amps are a pain in the *** to set up because everything is done digitally.

 

make sure that "safe mode" is turned off in the setup menu.