Hit an impedence snag

[GI JOEY 10+ year member]

Im in the middle of my build and noticed I ordered dual 4 ohm instead of d2 subs so with all 4 I will be at 2 ohms when I need 4ohms. So I will only be getting 1900 rms when I have over 500 rms more at 4 ohms. Guess I will have to live with my f up and get some dif subs or get another amp later. I was thinking about the sundown 3000d. But I also want to get some DC level 3's. Wish I pad a little closer attention to what I was doing.

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[grimreper912003 5,000+ posts]

Im confused. What amp are you using?

 

[GI JOEY 10+ year member]

JBL BPX 2200.1

2450 rms x1 at 4 ohms

1900 rms x 1 at 2 ohms

650 x 2 at 4 ohms

I think 1 ohm is like 1500 rms.

I jus thought about the imp rise though. If I am at 2 ohms at rest if I begin powering the subs I could see a rise closer to 4 ohms at full power. Hmmmm any ideas on this one?

 

[Alc5M 10+ year member]

not completely sure, but from what i read on a different forum, that amp is regulated like the jl's so it puts out the same watts at any ohm load, but i could be wrong

 

[GI JOEY 10+ year member]

Well according to what I have read and heard 4 ohms gets its most power. This is an AB amp not a D like the JL's. I wish it were like that. I should have thought about this before I bought the subs. I was talking with another guy and he said he was seeing a rise to almost 8 from 4 ohms. So If I were at 2 and burped to almost a 4 I would be happy. He said hat I would be getting more power across the board being at 2 because the closer I get with rise to 4. I am not sure what I will see because of the box being larger than recommended. I can only hope for a little rise. Ill take whatever the box and subs give me. atleast I know I will never drop below 2 ohms and the 1900 watts. I bet there is a much bigger drop from 4-8ohms

 

[Villeza1 10+ year member]

JBL BPX 2200.1 2450 rms x1 at 4 ohms

1900 rms x 1 at 2 ohms

650 x 2 at 4 ohms

I think 1 ohm is like 1500 rms.

I jus thought about the imp rise though. If I am at 2 ohms at rest if I begin powering the subs I could see a rise closer to 4 ohms at full power. Hmmmm any ideas on this one?

You got the ohm loads wrong. 4 ohms should have more resistence therefore should not be more powerful at 4 ohms. 1 ohm load is the least resistance so therefore it will have more power. 2 Dual 4's can still drop to a 1 ohm load if ran parallel.

EDIT: Oh, I see your confusion. It's 2450 rms at 4 ohms bridged.

 

[GI JOEY 10+ year member]

This is what I have found on this amp so far.

BPx2200.1

• 650W RMS x 2 channels at 4 ohms and

• Signal-to-noise ratio: 67dBA (reference 1W into 4 ohms)

• 2450W RMS x 1 channel at 4 ohms, 14.4V supply and

• 1810W RMS x 1 channel at 1 ohm, 14.4V supply and

• Dynamic power: 2940W at 4 ohms x 1 channel

• Effective damping factor: 6.28 at 4 ohms

• Frequency response: 22Hz – 302Hz (–3dB)

• Maximum input signal: 7V

• Maximum sensitivity: 250mV

• Output regulation: .12dB at 4 ohms

• Dimensions (L x W x H): 12-1/4" x 21-5/8" x 2-9/16"

 

[GI JOEY 10+ year member]

You got the ohm loads wrong. 4 ohms should have more resistence therefore should not be more powerful at 4 ohms. 1 ohm load is the least resistance so therefore it will have more power. 2 Dual 4's can still drop to a 1 ohm load if ran parallel.
EDIT: Oh, I see your confusion. It's 2450 rms at 4 ohms bridged.

This amp is odd. It has more power he closer you get to 4 ohms. So bridged at 2 ohms its only around 1900. Then 1800 at 1. I havent seen an actual birthsheet on 2 ohms though. I have been looking all freakin day.