Amp Wattage and Subwoofer Ohms

[bostonwhaler23]

Ok so I have a 2 channel 1800 watt crunch amp and I am running a skar 800 watt max competition dual voice coil sub on it at 1 ohm. Before this sub I had a 10" sony home theater sub. I was able to give the home theater sub much more power, even though home theater sub are supposed to have a much lower wattage rating. ( I think the home theater sub was around 100 watts). Why is my skar(which seems much tougher and can handle higher wattage) not handling my amps power very well? Is it the ohms? Btw my amp is supposed to be 4ohms bridged and 2ohms per channel.

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[Popwarhomie 5,000+ posts]

Skar sucks
Max wattage means nothing. RMS is all that matters
The enclosure is what makes or breaks a soundstage.


What subwoofer?
How is it wired?
What box is it in?

 

[bostonwhaler23]

It's a big sub even though it's an 8". I have it in a 10" ported box. (I built a bracket so it would fit) Rms wattage is 400 but that is still more than my other sub and it's not handling the power as well as my other sub did

 

[Popwarhomie 5,000+ posts]

Sooooooo its a Skar MA-8 in a prefab made for a 10" subwoofer.

What ohm load subwoofer is it? How is it wired to the amp?

What does "its not handling the power" mean? It's getting hot? Over excursion?

Are you running it bridged at 4 ohms on that amp?

 

[1aespinoza 10+ year member]

The Sony ht sub is an 8ohm sub. Say the amp pumps out 800 watts rms @4ohms bridged, then at 8ohms, it will be roughly half that power. So the Sony ht sub received about 400 watts rms. Now the Skar sub is wired at 1ohm. So rule of thumb is that a lower resistance extracts more power from the amp. If your amp pumps 800 watts rms at 4ohms, then logic would state around 1200 watts rms@2ohms and 1600-1800 rms@1ohm. Being your sub is 400 rms, you are killing it, and killing your amp as well. Amp is not designed to play at 2 or 1 ohm bridged. Best bet is to wire your sub at 8ohms and bridge the amp. It will receive 400 watts rms and both sub and amp will be happy. Good luck.

 

[THATpurpleKUSH 5,000+ posts]

The Crunch amp you are using is only about 100w rms in reality, they are very over rated. The ht sub is likely more sensitive and takes less wattage to get moving to the same excursion as the Skar. The Skar sub is a poor design and inefficient and will likely need far more power than the Crunch amp can provide to get moving to the same level as ht sub. A big magnet means nothing.

 

[bostonwhaler23]

Ok Thanks. I'm either gonna run it at 1ohm one one channel instead of bridged, or bring it up to 4ohms and bridge it

 

[bostonwhaler23]

One more question actually. Right now I'm running the sub at 1 ohm on one of of the amp's 2 channels, which is 2ohm stable. Sounds ok. Will I get better sound/more out of my sub if I get a class D mono amp that is 1ohm stable?

 

[1aespinoza 10+ year member]

One more question actually. Right now I'm running the sub at 1 ohm on one of of the amp's 2 channels, which is 2ohm stable. Sounds ok. Will I get better sound/more out of my sub if I get a class D mono amp that is 1ohm stable?

No need for another amp, just run it at 4ohms and bridge it. Also turn down the gain to where you see that the sub operates smoothly. A class D will sound just the same, but use less power. I personally like to use class a/b amps on my subs. Less efficient but sound better to my ear. On my earlier post I misread your sub's resistance and thought it was dual 4ohm. Just realized it is dual 2ohm.