Njord

After replacing my blown Alpine 10" Type-R 3 months ago; I am in the same predicament again. This weekend, when driving for ~3hours my sub faded away and the cabin started to smell like burnt electronics. I opened the trunk to find a cloud of smoke and more pouring out the port of the box.

Both subs were powered by my alpine mrp-m500. Before they smoked out they sounded amazing, but I guess the problems lies when running them at rated power for extended periods of time.

Q1
Should I stick with the cheap Alpine type-r (~$120 each) and hope I don't get the urge to crank it, or get a sub ~800Wrms range, which should happily take 500wrms for extended periods of time. (Needs to be 10" to fit my box)

Q2
I had a box recently designed for my needs (single 10" 1.6ft^3 @ 35Hz) and it sounded great before my sub packed it in. I would like to keep it but if I go for a new sub the displacement would be different. What would be an acceptable difference that would keep by box in tune?

Q3
The first type-R I had, one of the coils (4ohm DVC) have no continuity but the other coil reads 4ohms. When pushing on the cone there is noticeable grinding. The recent one that smoked still reads 4ohms across one, but 2-3ohms across the other. The coils are still separate and there is no noticeable grinding. Do you think its worth a shot to power it back up and see what happens?

Q4
Is there anything I can do with subs with damaged voice coils? I have 2 Type-R 10" and a Kicker CVR 10" with burnt voice coils now. They were all powered by my alpine mrp-m500, and all died on my 3 hour trips.

I just noticed that the new Type-Rs are 600WRMS now. Maybe worth another shot? I think the displacement changed from the different versions. Last years model was ~0.067ft^3. 2010 is now 0.08ft^3. Think this could be a problem?

Right now I'm using a pair of Rockford Fosgate RFR2212 (i think that was the model #) 12" in a ported box that I borrowed from a friend. Its been sitting out side under a car port for ~6 years, and the subs have a stamp that reads: Manufactured in 1998 Aug 20. I was so surprised they worked and they don't sound that bad and they go loud. Should have seen the dust/spiders that came flying out when I powered them up.
They look like this but they're 12" 4ohm SVC, rated 200Wrms from what I've found.

FusionMadsen

iTrader: (4)

Turn down the gain, probably being overdriven.

wvince

Answer to Q3. NO! Do not hook it up and find out what happens. You may not like the outcome. If the VC already reads 2-3ohm when it should be 4, then there already is a short in it. If it drops more, then you put your amp at risk of too low resistance and could cause damage to it.

Njord

Forgot to get to my point.

Does anyone know anything about these subs? The box they're in doesn't look like a prefab and it doesn't look like it was properly designed (looks like they just cut a hole in it and screwed a aeroport) If these subs where decent back in the day, I'm thinking it might be worth while to get a proper box and maybe sell them.

The gain on the alpine MRP-M500 is just above normal.

wasted911

iTrader: (2)

There technically is no "normal". Theres having it set properly vs improperly.

Unfortunately yours was improperly. Back the gain down, then pick a new sub.

curtis0432

Ok so how do you set your amplifier properly?

I really do not want to blow any of my subs.I got amp set up and the gain is around 3/4 to the max the amplifier will do . Do you think I could have damaged my sub.. it still seems to be working good. Doesn't turning up the gain just make the sub woofer sound more deep and loud? Can some one tell me what the ***** on the amp actually do and how to set them. like the Bass Boost,LP Filter, and Gain.

Thanks.

Njord

If the amp was clipping my sub would have sounded worse, not better. Where it was set was a perfect level to meet the front speakers.

You can see the settings layout on page 11:
http://vault.alpine-usa.com/products/documents/OM_MRP-M500.PDF

Mine is in between nom and 0.5. Probably closer to 0.5, but I cant remember.

DeadlySones

iTrader: (4)

Depending on your HU you should have it set closer to the min level. Maybe the first line. If you have to turn it up that high to balance your highs then you need more power or a box/subs that will be louder.

You are definitely clipping the subs with gain set that high with most HU. Unless your HU is only 2v....

Looks like its a good excuse to upgrade.

Spawn-Inc

iTrader: (1)

grab Mach 5 Audio 10" IXL-BR sub , only 150 and can do 1000watts with ease.

i have 2 IXL12's on 2000watts and it sounds great, got me 143db and that was with electrical problems and not a properly sized alt.

Njord

My Head unit is a Eclipse CD5030. It has 5V preouts and I 'tuned' my system to the volume 65/80 on the deck. So its getting ~4.1v on the RCAs (assuming its output is linear). Thinking about it like this would lead me to believe the MRP-m500 was clipping if the 'normal' setting on the gain is expecting such a low input level (as said above ~2v. But it shouldn't as line level is slandered 5v therefore normal should be 5v. The difference in gain I set should compensate for the slightly lower line level I'm feeding it), but the sub didn't sound any different. Well, other then louder.
Not to mention I've ran this sub and the previous type-r at this gain since I got them. It wasn't until i rolled down the windows when nice weather came and ran them at 65volume (system max) for extended periods of time. Normally for the long drives I keep it lower (55-60). For the short rides around town I usually max out my stereo. Like I said, I've only blown subs during the long ride, so for extended periods of use.
For those who are arguing gain problems; Are you saying the RMS rating of a sub is for an infinite amount of time? I think this is where the problem is as RMS would imply an infinite amount of time, but the manufacters are lying for marketing purposes. Lying might be strong words, rather stretching the truth (as it could run 500WRMS for an hour straight before thermal problems occur)

I don't understand why all the mystery in the car audio world about gains. In my world when dealing with amplifiers (for communications ect..) they all come with datasheets showing the formula/constants for calculating gain x input -> output.
They make it ambiguous like this probably for marketing purposes as its near impossible to directly compare.

I want to know what the real problem is. I want to fix this and be done with it. As my system before cooking this sub was perfect for my type of music.