the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
icon

1ohm-2ohm-4ohm?


Post ReplyPost New Topic
< Prev Topic Next Topic >
yeovil 
Member - Posts: 12
Member spacespace
Joined: April 17, 2003
Location: United States
Posted: April 18, 2003 at 11:33 PM / IP Logged  

I have a RF 1000bd amp that I planned on using with ONE RF HX2 RFR3112 12"sub. I asked thr RF dealer what amp to use with this sub, and that I only wanted to use one because I'm putting it in my Miata trunk-not the largest of spaces-I'm actually removing my spare and mounting it under the car-a whole other story, and he told me the 1000bd. From another post I was told the following:

 Your RFR3112 is a 2ohm DVC, so you can only wire into 1 or 4ohms, not 2 (at least not with just 1 2ohm DVC). If your running at a 4ohm total load, then you're only seeing around 500watts RMS, not 1000 (which you could get at a 2ohm total load).

What kind of effect will this have on my sound quality? I'm not concerned with being able to knock buildings over with the sub, but I do want it to be reasonablty loud. Am I OK like this or do I need to get a 2nd sub to cram in my trunk to improve the sound/volume? Any help is appreciated

If you're getting old-turn it up so it still sounds the same-If you can't turn it up any higher -get a bigger amp.
wvsquirrel 
Gold - Posts: 1,237
Gold spaceThis member has made a donation to the12volt.com. Click here for more info.spacespace
Joined: July 27, 2002
Location: Florida, United States
Posted: April 18, 2003 at 11:49 PM / IP Logged  
Sorry they did that to you. Here's what you can wire with one 2ohm DVC
1ohm-2ohm-4ohm? -- posted image.
1ohm-2ohm-4ohm? -- posted image.
You would deffinately notice a difference between 1 and 4ohms. At 1ohm, your single RFR3112 would be getting 1000watts (which is the RMS rating for that sub). At 4ohms, you would only be getting 500watts. That's seriously underpowering a sub rated at 1000RMS 2000Peak. RF amps are usually pretty good with their circuit protection, and since you already have the equipment give it a shot at 1ohm. If it goes into protect mode then you will know you have to switch to 4ohms, or get a different sub(s). Make sure to turn the gains down when you are in 1ohm mode.
I'm kinda contradicting myself from an earlier post, because I didn't want to run my old 500bd @ 1ohm without knowing it was stable first. But I had not already bought the replacement subs, and I didn't want to go through the hassel of returning them in a couple of days! So I went with a guarenteed 2ohm stable system (subs and amp)
It surprises me that 4 RF Techs advised me against running at 1ohm, but they told you to try. Maybe it was because I asked specifically about the Power 500bd, not the Power 1000bd. But, even the manual for the Power BD series (500bd, 1000bd, and 1500bd) does not rate any of those amps at 1ohm, or say that they are 1ohm stable. There's nothing on RFTech about any of the BD's being 1ohm stable either.
I'd at least try the 4ohm setup first and see if you like it (especially since you said you were after more SQ then ground pounding SPL). Then try the 1ohm setup briefly, and with the gains turned way down. But without that factory warrenty you're stuck dealing with the company (or individual) that sold them to you if anything blows. And they may try and screw you out of a replacement if they find out that you tried to run a 1ohm load on an amp that has a minimun load of 2ohms.
Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com
speedwayaudio1 
Silver - Posts: 879
Silver spacespace
Joined: March 18, 2003
Location: United States
Posted: April 19, 2003 at 12:39 AM / IP Logged  
Go for 1 ohm. Just make sure you have plenty of power to run a 1000w rms amp. if you have a weak alt and small batt. it's gonna sound crappy anyway. so if you have a good alt and batt. go 1ohm. if not go 4 ohm. when i say good alt i mean one that is 120amps at least. and at least a 800cca batt.
Big Dave
yeovil 
Member - Posts: 12
Member spacespace
Joined: April 17, 2003
Location: United States
Posted: April 19, 2003 at 10:55 PM / IP Logged  
Would running a 2nd RFR3112 solve this as well. That would give me the 2 ohm and 1000 watts if I'm understanding this correctly. I bought an Alumapro cap 5 capacitor to help on the power as I was told that would cover any battery/alternator issues. I also assume since the recommended enclosure space is 1 cube, I double that for volume for 2?
If you're getting old-turn it up so it still sounds the same-If you can't turn it up any higher -get a bigger amp.
wvsquirrel 
Gold - Posts: 1,237
Gold spaceThis member has made a donation to the12volt.com. Click here for more info.spacespace
Joined: July 27, 2002
Location: Florida, United States
Posted: April 21, 2003 at 11:30 PM / IP Logged  
Yes, a second RFR3112 would allow you to run at 2ohms, and would give you apx. 500 watts to each sub (1000 total from the amp). You'll only be pulling half the recommended RMS rating for the subs though (since they're rated at 1000RMS each). I'd recommend returning the one RFR3112, and getting Two RFD2112 HX2's. They're 2ohm DVC's rated at 500RMS, 1000 Peak. I have this setup and it pounds. The sub's RMS rating and the amp output are a perfect match (1000watts @ 2ohm, 500 watts per sub).
1ohm-2ohm-4ohm? -- posted image.
Caps are not a "fix all". They are meant for voltage (power) regulation. The battery charges the cap, and when the amp pulls a sudden surge (ie. extreme bass hit), then the cap already has the juice stored for it. But then the cap has to be recharged from the battery and the cycle starts over again. If you still get dimming, you might need to look into either a better battery, a second battery setup, and/or a larger alternator.
As far as enclosure size goes, the 1.0 is per chamber. Each sub should be in its own chamber for sealed enclosures. So, you would need a box with Two 1.0 cubic ft. chambers.
Squirrel
"No more Cpt. Kirk chit chat"
If its too loud, then you're too old
Donate to the12volt.com

Sorry, you can NOT post a reply.
This topic is closed.

  Printable version Printable version Post ReplyPost New Topic
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot delete your posts in this forum
You cannot edit your posts in this forum
You cannot create polls in this forum
You cannot vote in polls in this forum

  •  
Search the12volt.com
Follow the12volt.com Follow the12volt.com on Facebook
Thursday, May 15, 2025 • Copyright © 1999-2025 the12volt.com, All Rights Reserved Privacy Policy & Use of Cookies
Disclaimer: *All information on this site ( the12volt.com ) is provided "as is" without any warranty of any kind, either expressed or implied, including but not limited to fitness for a particular use. Any user assumes the entire risk as to the accuracy and use of this information. Please verify all wire colors and diagrams before applying any information.

Secured by Sectigo
the12volt.com spacer
the12volt.com spacer
the12volt.com spacer
Support the12volt.com
Top
the12volt.com spacer
the12volt.com spacer