I am still a little unclear on the results I would have if I wired 2 DVC 4 Ohm subs to my RF 6001bd amp.
Using 2, 2DVC. 4 Ohm subs
If I wired the VC's in series does that net a 4 Ohm total load? My amp has 2 sets of sreaker outputs and the manual shows each speaker needs to be a minimum of 4 Ohms when using 2 subs.
So if the amp is good for 300 watts at 4 Ohms, is that going to be 150 watts to each driver or 300?
Replies (11)
ttocs on 04/21/2007 19:36:46
if you wire each of the VC's in series, you will have 4 - 4 ohm voice coils in series which means you add them all up. You would have a net impedence of 16 ohms. You will need to do a series parallel configeration with 2 in series, and 2 in parallel to get a 4 ohm load to your amp. That power will be divided equally between the VC's so if your amp puts out 300 watts at 4 ohms, you will have 75 watts per driver, and 37.5 watts per VC.
jamesp on 04/21/2007 19:48:53
Thanks, I currently have a single Alpine 4+4 wired to 2 Ohms getting 600 watts. Is there any way to use 2 subs and get 300 watts to each one?
swez on 04/22/2007 11:04:40
Only if the amp was 1 ohm stable. Then you could wire both subs full parallel.
This amp is not rated for 1 ohm loads, but some guys have done it with some degree of success on other RF amps. The NOmad circuit may or may not permit a 1 ohm load over a sustained time at full power. It's designed to sense current flow, temperature of the output devices and impedance loads. If any of these go outside preset operation parameters, the amp will go into protect mode.
Another option if you want dual subs, consider a pair of 4 ohm SVC's that are at least rated at 300-350 Wrms per each. (Infinity Kappa 122.7's) They are rated at 92dB SPL @ 1w/1m. These are more efficient than the Alpine type R. (85 dB SPL @ 1w/1m)
The last option here, port the Alpine R and go with a larger box. Power handling will deminish a little here and so will the chrispness of the overall bass will not be as noticable too. If you port tuned at say 35 Hz., the deep lows will be stronger by about +3dB.
Swez
ShootuhMcBustaCap on 04/22/2007 11:34:15
I have a wierd thing about amp stability. I never follow the rules. My POS amp holds 2 ohms bridged no problem, but I keep the gain way low. It does get pretty warm, but I have had more thermal problems with different amps running on higher loads. Really depends on how thuggin yo amp be. See how good it break the rules!
I hate to be the suggestor of breaking the rules here, but James if I were in your situation, I would push my luck a little. But only a little at first. I would try sticking 4 4-ohm loads up to her for a few minutes just to see what it does. If it goes straight into protect, than scratch that. I am not too sure on what the NO circuit is, but I am the type to play though.
The ported box idea is nice, and would be a solid and virtually free way to get some extra bumps from the old Alpine. I also like the idea of a pair of higher sensitivity, SVC subs. But that could stress the smaller cabin of some room. I believe you already have stated that one of your rear comp speakers fires derectly into your box right? Maybe a pair or more of smaller subs slung under the rear seats (two 10's four 8's) could do the trick, while preserving the goals of a nice SQL vehicle.
I just figured I would throw some ideas up in the air, since adding on is always fun. But, just a quick question James, are we needind bump, or getting bored? Just curious. I need some new projects myself!
30Hertz on 04/22/2007 15:35:17
If you run a amplifier below its ratings for ohm loads you run the risk of damaging your amplifier. It may work fine for a little while but is it worth ruining your amplifier? Probably not, also if the amplifier was under warrenty, or still under the manufacturers warrenty it is now void because you ran it in a way that is not reccomended.
Before you run anything below its reccomended specifications you should at least call the manufacturer to get more information. Ofcourse they'll tell you its not reccomended but you can then ask why and get a better understanding of the amplifier and how it will react.
30-
jamesp on 04/22/2007 17:35:04
I am happy with the setup I have as far a sound...I just want to shake things up a little and thought if I could get a pair of Infinity Kappas and could give them 300 watts each, I would like to try it.
I dont understand how I can use a single sub at 2 Ohms and have to have a 4 Ohm load if I use 2 subs. I have read everything I could find, looked at the wiring possibilities a 100 times...my dyslexia has something to do with this..and it is not connecting in my feeble brain.
The RF manuals really dont explain anything... there is only a diagram
The amp has 2 sets of speaker inputs that must be wired to the single channel available...why cant it work properly with 2 , 2 Ohm speakers?
If I used 2 Infinity Kappa 4 Ohm subs, would they only get 150 watts each? If the answer here is 300 each, I want to do it using sealed boxes.I like the sound of my sealed box better than the few ported boxes I have heard at the audio shop...The ported boxes I have been able to listen to belong to guys that are only into SPL. I dont know anyone that has an SQ system with ported boxes....Of course none of my buddies even have aftermarket systems.
I can still get a good deal( I think) on another RF 6001bd amp and would love to have 2 of them with the second one set up just like I am using the one I have , 4 Ohm DVC Alpine type R wired parrell to 2 Ohms...BUT, I know this would be a stretch on my electrical system..
The main thing is I just dont want to call this project done just yet
jamesp on 04/22/2007 21:30:13
Shootah, I have the space under the rear seats full with the 2 amps now and the height is very low in the 97 and 98 models as they designed them to provide a solid sheetmetal shelf behind the front seats when you fold out the rear seats. If I wanted to get crazy and give up passenger capability in back, I could do that or just remove the rear seat and start stacking up the audio stuff.
I am starting to get interested in the Alpine PDX series. I could stack up 1 of each model, as they have a very small footprint and are all the same size and go for a sweet 5.1 setup...check out page 5 of the manual and see what you think...wonder how much a PXA-H 701 digital compatible processor can be found for?...Dont know how many of the features will work with my Eclipse H/U either, maybe enough, Im trying to find out...Looks sweet but would burn a BIG hole in my back pocket for sure.....
http://akamaipix.crutchfield.com/Manuals/500/500PDX1100.PDF
swez on 04/22/2007 23:36:03
We can explain the details of sub wiring to you if desired. However, with the sub you have now, adding a 2nd like sub means rewiring the subs to the amp and you get a 1 or 4 ohm load. Neither is optimal.
If you have the space and want to try a pair of Infinity Kappas, this make sense and with the reported efficiencies, I would anticipate a notable difference in SPL and still have very good SQ with that very amp. (Sealed box) Both the Infinity and Alpine are considered SQL subs.
Even if you added a 2nd RF amp and another Alpine type R to match, I don't think it will stack up money VS performance wise to a pair of Infinity Kappa subs with your present RF amp. (Yes, they are that good too) The additional power drain of a 2nd RF amp will probably mean some major electrical upgrades.
Don't get me wrong here... the Alpine type R is a fine sub, paired with your present RF amp. It was the best cost/performance/space option within the confines of the system parameters we discussed originally. If you want to bump up the bass a few more dB and not add another amp, the Infinity's mentioned are a good next step.
Swez
trunkisloud on 04/22/2007 23:57:08
i feel your pain james ..as i am dealing with this right now only being able to run my amp at 4ohms due to the sub configuration..of course they are not type r's (i wish) so its a little easier to power them ....something i can live with for a week or two..until the ed is in the trunk.
jamesp on 04/23/2007 07:13:20
Swez, if I used a pair of Kappas, single 4 Ohm VC's, would 150 watts to each sub be what I would get?
swez on 04/23/2007 11:21:58
Depends on how you wired them. If you used a pair of 4 ohm SVC's in parallel, the amp would see a net 2 ohms, be safe for the amp and each sub would recieve 1/2 the amps rated power at 2 ohms. (Over 350 Wrms/sub right?)
If wired in series, that nets an 8 ohm load and amping power would be well under optimal. (About 150 Wrms/sub)
If I recall your earlier posts on this RF BD 600.1, it's birth sheet states about 790 Wrms @ 2 ohms right? That amp is definitely under-rated and can supply almost 400 Wrms per sub. That's nothing to sneeze at.
FYI: Amps are AC power boosters. Their power ratings are generally based on ohmic loads they see at the output side of the amp. The higher the resisitive load it sees, the lower the wattage output the amp will deliver. Conversely, if the ohmic value is low, (Say a net 2 ohms optimal) the power output is whatever the amp can deliver at 2 ohms.
There are a few amps on the market that don't care what the ohmic load is to the amp. JL's Slash series is a bit unique as it is able to provide optimal output with a range of ohmic loads. (1.5 - 4.0 ohms) This feature is semi-unique to JL Slash amps and the Xenon series amps from Phoenix Gold. There may be a few newer amps that have this power supply system as well. I think Infinity and JBL now offer a amp that uses this type of technolgy too. This power supply design allows many speaker wiring configurations to be used and still delivers optimal power.
Got all that?
Swez
Using 2, 2DVC. 4 Ohm subs
If I wired the VC's in series does that net a 4 Ohm total load? My amp has 2 sets of sreaker outputs and the manual shows each speaker needs to be a minimum of 4 Ohms when using 2 subs.
So if the amp is good for 300 watts at 4 Ohms, is that going to be 150 watts to each driver or 300?
Replies (11)
ttocs on 04/21/2007 19:36:46
if you wire each of the VC's in series, you will have 4 - 4 ohm voice coils in series which means you add them all up. You would have a net impedence of 16 ohms. You will need to do a series parallel configeration with 2 in series, and 2 in parallel to get a 4 ohm load to your amp. That power will be divided equally between the VC's so if your amp puts out 300 watts at 4 ohms, you will have 75 watts per driver, and 37.5 watts per VC.
jamesp on 04/21/2007 19:48:53
Thanks, I currently have a single Alpine 4+4 wired to 2 Ohms getting 600 watts. Is there any way to use 2 subs and get 300 watts to each one?
swez on 04/22/2007 11:04:40
Only if the amp was 1 ohm stable. Then you could wire both subs full parallel.
This amp is not rated for 1 ohm loads, but some guys have done it with some degree of success on other RF amps. The NOmad circuit may or may not permit a 1 ohm load over a sustained time at full power. It's designed to sense current flow, temperature of the output devices and impedance loads. If any of these go outside preset operation parameters, the amp will go into protect mode.
Another option if you want dual subs, consider a pair of 4 ohm SVC's that are at least rated at 300-350 Wrms per each. (Infinity Kappa 122.7's) They are rated at 92dB SPL @ 1w/1m. These are more efficient than the Alpine type R. (85 dB SPL @ 1w/1m)
The last option here, port the Alpine R and go with a larger box. Power handling will deminish a little here and so will the chrispness of the overall bass will not be as noticable too. If you port tuned at say 35 Hz., the deep lows will be stronger by about +3dB.
Swez
ShootuhMcBustaCap on 04/22/2007 11:34:15
I have a wierd thing about amp stability. I never follow the rules. My POS amp holds 2 ohms bridged no problem, but I keep the gain way low. It does get pretty warm, but I have had more thermal problems with different amps running on higher loads. Really depends on how thuggin yo amp be. See how good it break the rules!
I hate to be the suggestor of breaking the rules here, but James if I were in your situation, I would push my luck a little. But only a little at first. I would try sticking 4 4-ohm loads up to her for a few minutes just to see what it does. If it goes straight into protect, than scratch that. I am not too sure on what the NO circuit is, but I am the type to play though.
The ported box idea is nice, and would be a solid and virtually free way to get some extra bumps from the old Alpine. I also like the idea of a pair of higher sensitivity, SVC subs. But that could stress the smaller cabin of some room. I believe you already have stated that one of your rear comp speakers fires derectly into your box right? Maybe a pair or more of smaller subs slung under the rear seats (two 10's four 8's) could do the trick, while preserving the goals of a nice SQL vehicle.
I just figured I would throw some ideas up in the air, since adding on is always fun. But, just a quick question James, are we needind bump, or getting bored? Just curious. I need some new projects myself!
30Hertz on 04/22/2007 15:35:17
If you run a amplifier below its ratings for ohm loads you run the risk of damaging your amplifier. It may work fine for a little while but is it worth ruining your amplifier? Probably not, also if the amplifier was under warrenty, or still under the manufacturers warrenty it is now void because you ran it in a way that is not reccomended.
Before you run anything below its reccomended specifications you should at least call the manufacturer to get more information. Ofcourse they'll tell you its not reccomended but you can then ask why and get a better understanding of the amplifier and how it will react.
30-
jamesp on 04/22/2007 17:35:04
I am happy with the setup I have as far a sound...I just want to shake things up a little and thought if I could get a pair of Infinity Kappas and could give them 300 watts each, I would like to try it.
I dont understand how I can use a single sub at 2 Ohms and have to have a 4 Ohm load if I use 2 subs. I have read everything I could find, looked at the wiring possibilities a 100 times...my dyslexia has something to do with this..and it is not connecting in my feeble brain.
The RF manuals really dont explain anything... there is only a diagram
The amp has 2 sets of speaker inputs that must be wired to the single channel available...why cant it work properly with 2 , 2 Ohm speakers?
If I used 2 Infinity Kappa 4 Ohm subs, would they only get 150 watts each? If the answer here is 300 each, I want to do it using sealed boxes.I like the sound of my sealed box better than the few ported boxes I have heard at the audio shop...The ported boxes I have been able to listen to belong to guys that are only into SPL. I dont know anyone that has an SQ system with ported boxes....Of course none of my buddies even have aftermarket systems.
I can still get a good deal( I think) on another RF 6001bd amp and would love to have 2 of them with the second one set up just like I am using the one I have , 4 Ohm DVC Alpine type R wired parrell to 2 Ohms...BUT, I know this would be a stretch on my electrical system..
The main thing is I just dont want to call this project done just yet
jamesp on 04/22/2007 21:30:13
Shootah, I have the space under the rear seats full with the 2 amps now and the height is very low in the 97 and 98 models as they designed them to provide a solid sheetmetal shelf behind the front seats when you fold out the rear seats. If I wanted to get crazy and give up passenger capability in back, I could do that or just remove the rear seat and start stacking up the audio stuff.
I am starting to get interested in the Alpine PDX series. I could stack up 1 of each model, as they have a very small footprint and are all the same size and go for a sweet 5.1 setup...check out page 5 of the manual and see what you think...wonder how much a PXA-H 701 digital compatible processor can be found for?...Dont know how many of the features will work with my Eclipse H/U either, maybe enough, Im trying to find out...Looks sweet but would burn a BIG hole in my back pocket for sure.....
http://akamaipix.crutchfield.com/Manuals/500/500PDX1100.PDF
swez on 04/22/2007 23:36:03
We can explain the details of sub wiring to you if desired. However, with the sub you have now, adding a 2nd like sub means rewiring the subs to the amp and you get a 1 or 4 ohm load. Neither is optimal.
If you have the space and want to try a pair of Infinity Kappas, this make sense and with the reported efficiencies, I would anticipate a notable difference in SPL and still have very good SQ with that very amp. (Sealed box) Both the Infinity and Alpine are considered SQL subs.
Even if you added a 2nd RF amp and another Alpine type R to match, I don't think it will stack up money VS performance wise to a pair of Infinity Kappa subs with your present RF amp. (Yes, they are that good too) The additional power drain of a 2nd RF amp will probably mean some major electrical upgrades.
Don't get me wrong here... the Alpine type R is a fine sub, paired with your present RF amp. It was the best cost/performance/space option within the confines of the system parameters we discussed originally. If you want to bump up the bass a few more dB and not add another amp, the Infinity's mentioned are a good next step.
Swez
trunkisloud on 04/22/2007 23:57:08
i feel your pain james ..as i am dealing with this right now only being able to run my amp at 4ohms due to the sub configuration..of course they are not type r's (i wish) so its a little easier to power them ....something i can live with for a week or two..until the ed is in the trunk.
jamesp on 04/23/2007 07:13:20
Swez, if I used a pair of Kappas, single 4 Ohm VC's, would 150 watts to each sub be what I would get?
swez on 04/23/2007 11:21:58
Depends on how you wired them. If you used a pair of 4 ohm SVC's in parallel, the amp would see a net 2 ohms, be safe for the amp and each sub would recieve 1/2 the amps rated power at 2 ohms. (Over 350 Wrms/sub right?)
If wired in series, that nets an 8 ohm load and amping power would be well under optimal. (About 150 Wrms/sub)
If I recall your earlier posts on this RF BD 600.1, it's birth sheet states about 790 Wrms @ 2 ohms right? That amp is definitely under-rated and can supply almost 400 Wrms per sub. That's nothing to sneeze at.
FYI: Amps are AC power boosters. Their power ratings are generally based on ohmic loads they see at the output side of the amp. The higher the resisitive load it sees, the lower the wattage output the amp will deliver. Conversely, if the ohmic value is low, (Say a net 2 ohms optimal) the power output is whatever the amp can deliver at 2 ohms.
There are a few amps on the market that don't care what the ohmic load is to the amp. JL's Slash series is a bit unique as it is able to provide optimal output with a range of ohmic loads. (1.5 - 4.0 ohms) This feature is semi-unique to JL Slash amps and the Xenon series amps from Phoenix Gold. There may be a few newer amps that have this power supply system as well. I think Infinity and JBL now offer a amp that uses this type of technolgy too. This power supply design allows many speaker wiring configurations to be used and still delivers optimal power.
Got all that?
Swez
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