Haudi

Hi, I'm installing the following, and could use a little assistance:

1) JBL P80.4 4 channel amp:

http://www.jbl.com/resources/brands/...nual/bp_om.pdf

2) Hooked up to four 6.5" JBL GTO628 2ohm speakers:

GTO628 | 6-1/2" 2-way loudspeaker | JBL US

What are my wiring options? Can I take advantage of this amp's 80W x4 at 2 ohm?

I'd appreciate any input.

Thanks,

Sonic

iTrader: (1)

One speaker per channel with your amp tuned appropriately and you are good to go !

Haudi

That's what I was thinking, but I got myself all confused looking at all these wiring diagrams, seemed too simple! Thanks

TragicMagic

Yeah, because the resistance of those drivers is 2 ohms just as they are, all you need to do is connect them to the amp. The amp "sees" a 2 ohm load, and it's output is increased to that 80W immediately.

The wiring diagrams you're probably looking at are most likely related to multiple sub or voice coil configurations. They don't really apply in most door speaker applications...

Also, the RMS handling for those speakers is 60W. When you hook them up, you're going to have 33.333% more power available than those speakers are rated for. You'll have to be cautious with your volume and bass settings on your head-unit, and your cross-overs and gains on your amp. We'd hate to see you cook those speakers.

Haudi

Do you guys happen to have a quality article on how to tune it properly? Lot's of guys seem to believe in doing it by ear, but that sounds sketchy, especially with this amp rated higher than my speakers. Bring out the multi-meter?

Cooking these speakers would really suck, although they were only $33/pair on amazon........better than the 119/129 per pair at best buy! We'll see if they actually work when I get them though......

TragicMagic

To start, I'd set your Gain setting to minimum, and your High-Pass Filter to 120Hz or so. Turn off any "Bass Boost" settings, or "Loudness" levels on the head-unit - or any extra processing features that your head-unit has.

I think most would suggest you set your volume on your head-unit to 60-70% of full. This should keep your signal from being clipped before its sent to the amp.

Next, slowly decrease the HPF filter from 120Hz until you start to hear distortion -ideally you want to get down to 80Hz or so. Your speakers have a Frequency Range of 50-21000Hz, but that's at 60WRMS. Once distortion is heard increase the HPF enough to eliminate any distortion, and a little more to allow for you to increase the bass output from the head-unit. At this point if you feel that you want more volume from the speakers you can slowly increase the Gain setting to get your desired volume, or until it starts to create any distortion. Then you have two options, if you want to allow your speakers to handle more bass, then keep the Gain setting down, if you want more volume you can raise the HPF to allow the Gain to be increased slightly.
Personally, I'd lean towards a very low Gain setting, and getting the HPF as low as possible without creating any distortion. I prefer a fuller sound coming from the speakers over ear-piercing volume...

I hope I'm not leading you astray. Hope somebody else can shed some light on this as well.

Dilatory

iTrader: (1)

No I'd say that pretty much nailed it.

Only thing to do now is to get a sub to cover that 80 or 100 and down xD