How is this possible and will it catch on? Infinity Kappa 120.9w sub

[pro-rabbit 5,000+ posts]

I have one of those subs in my car now. a older model thats a switchable 2 or 8 ohm imp. I always had it a 2 ohms though for 350 watts max. I have a Alpine MRP -M450 amp pushing 400 watts at 2 ohms in a 03 Honda Accord. Honestly, the sub... DID well with hiphop music. Until one day I added polyfill in the enclosure, (no real clue why other then reading random online ish), played a track wiith HEAVY bass for a good 5 mins straight and suddenly, no bass. Took that ish out, put sub back in, sub would bang hard for a good amount of time as long as the bass wasnt too deep and loud, then... no bass. Now when i tap on the sub at different spots i get a rattling within the sub and i have no clue on how to repair subs. Could be that the sub blew because of an extra 50 watts and polyfill, but if so, i believe the sub would be considered sh*t. Basically to sum it all up, I wouldnt recommend one. For the same price, I got my eye on a Sundown brand ( for no real reason other then reading random online ish).

Your sub was damaged do to user error. The product did not fail on it's own.

 

[zako 10+ year member]

I have been using a Kappa 120.9w for a several months now. It's a nice subwoofer for a "budget" SQ setup. Give it 1cu ft sealed box (filled with polyfill) and 300watts, and it will surprise you. Give it a spin with the kind of music that's present on Focal's JMLabs Demo CDs. Bass will sound deep and tight. Give it an SPL track, and it will rattle panels in the trunk. Of course, the xmax rating of 17mm or so suggests, after modeling excursion with WinISD, that in this sealed box it can take 500-600watts and still stay within its xmax. Right now I use it with PPI P900.4 (~450watt at 4ohm).

 

[zako 10+ year member]

I have one of those subs in my car now. a older model thats a switchable 2 or 8 ohm imp.

Based on the description, it's the older model, most likely the Kappa 124.7w with the neo motor. The current 120.9w is likely very different design. Neo motor is no longer used, and the number of voice coils is supposedly 3. The old one also had 12.5mm xmax. I would agree that this is not an SPL sub for daily burps. Maybe it would shine in a vented box for that purpose.

 

[zako 10+ year member]

Kinda nifty ,but how many times dose someone need to change impedance on their subs to need a switch.

The cool thing is that it switches between 2 and 4ohms. Not between 1ohm or 4ohm, or between 2ohm or 8 ohm. For a lot of people, at least one of these options (1ohm or 8ohm) is not very practical. 2vs4ohm switch is handy for those who constantly mess around with their setups (e.g. if you decide to move the subwoofer from say a 2ohm stable mono channel to 4ohm-only stable bridged channels.) Another possibility, run single sub at 2ohms. If not enough output, buy second, switch both to 4ohms, wire in parallel for the final 2ohm load.

 

[Shinju 10+ year member]

I had one, never got to use it I think it was a pretty cool solution for not having to run muli woofer setup's. Infinity is like the SEGA of the Car Audio world, They come up with killer idea's first that never take off or cost alot or someone else makes it better down the road.

There was a Video on youtube that explains the coil config and how it works and I am not talking about the Sonic Electonix one.

 

[THATpurpleKUSH 5,000+ posts]

Boston Acoustics has a similar "idiot proof" ohm setting called Sure Set. I think they have a patent on it too. Instead of a switch it uses fuses and will protect the voice coils from momentary overdrive. I've managed to pop a fuse twice on the G1s that I have owned while doing burps.