Alright. I have 2 12" kenwoods in a ported box. I want to bridge them. First I need an amp. I have 2 choices...

Kenwood KAC-7251
2-channel
150 watts RMS x 2 at 4 ohms
230 watts RMS x 2 at 2 ohms
460 watts RMS x 1 bridged output at 4 ohms
stereo or bridged mono output
4-ohm stable in bridged mode

Kenwood KAC-8151D
1-channel
200 watts x 1 at 4 ohms
400 watts x 1 at 2 ohms
500 watts x 1 at 1 ohm
1-ohm load capability

Which one is better for bridging two 4ohm 12" subs?

 

you would have to go with 8151D if your choice is between those two, because if u bridge two 4ohm subs, you will get a 2ohm impedence.

and only the 8151D model can handle 2ohm (@ 400watts)

if u bridge your subs and run them to your 7251 model, your amp cant handle the low ohm load and it wil leventually blow however, u could run each sub seperate to the 7251 model (not bridged) and that would work, you would get 150watts out of it which is alot weeker then the 8151D model which would put out 400watts.

 

Well I searched the kenwood website and I was able to come up with this for the KAC-7251.

POWER RATINGS
- Bridged Power Output at 14.4V (1kHz, 0.8% THD): 460 Watts x 1
- Maximum Output Power: 800 Watts
- Power Output at 2 Ohms, at 14.4V (1kHz, 0.8% THD): 230 Watts x 2
- Power Output at 4 Ohms, at 14.4V (20Hz-20kHz, 0.08% THD): 150 Watts x 2

AUDIO FEATURES
- 2 or 1 Channels of Amplification
- Ground Isolation Circuit
- High-Pass Electronic Crossover: 150Hz, 12dB/oct (Switchable)
- Quiet Turn-On
- RCA Audio Inputs: Gold-Plated
- Speaker Connectors: Screw-Type
- Speaker Level Input Terminals: Plug-Type
- Stereo, Mono, or Tri-Mode Operation
- Variable Low-Pass Electronic Crossover: 50Hz - 200Hz, 18dB per Octave
- Bass Boost: Off/+6/+9/+12dB (Remotely-Controllable)

POWER SUPPLY FEATURES
- 2-Ohm Stable
- Copper EE-Core Power Transformer
- Noise Supression Filter: Toroidal
- Power Input Terminals: Gold-Plated, Large Screw-Type
- Power MOSFET Switching Power Supply
- Power Supply Fuse: 2 x 30A
- Secondary Capacitors: 2


I highlighted the 2-ohm stable part. Is the KAC-8151D still the better amp??????

 

the class AB amps are generally 2 ohm stable in STEREO operation, at least in this price range anyway.



adam

 

yes class ab would be better for your application

 

i would go with the class D because i dont think the first amp will run at 2ohm mono for too long. Plus if you get a 1 ohm stable amp there's room for upgrading down the road.

are your subs SVC or DVC?

 

My subs are SVC.

I can get both amps for $200 canadian...that's why I wasn't really sure whats better. I took everyones advice and put a down payment on the class d....there was only one left out of 8. They sold 7 in one afternoon which should have told me something right there lol.

 

good job, report back with results

 

It was my birthday yesterday, so for one of my "presents", my dad gave me my downpayment back and paid for the whole amp himself. I installed it today, it was my first time so I hit a few snags.
All in all it took me about 6 hours:lala:

Anyways, I bridged the amp, tweaked it a bit, and it POUNDS. It's probably not quite as loud as most setups here but it's loud enough for me. I got back from cruising an hour ago and my ears are still ringing

 

nice man...glad it worked out for ya. Just make sure you boom responsibly and dont show it off too much or it might get stolen