vintage 5.0
vintage 5.0
I have a Aragon 4004 MK II. Can I run two sets of speakers in parallel. One set is 8 ohm and one is 4 ohm. Will that work or is there a possible risk to the amp from doing this.
Speaker question
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soundmotor
super modified
Interweb expert here...
The rating on the speaker is often driven by marketing as much as engineering data, sometimes more. So, ideally you'd want to know what the minimum impedance dip for each speaker is and use that as the baseline to calculate the load. OTOH, your Aragon is a beast. I seem to recall it had the ability to drive Apogee Chinchillas with ease and would mock your question if within earshot. That is when it takes a break from driving dead shorts for amusement.
The rating on the speaker is often driven by marketing as much as engineering data, sometimes more. So, ideally you'd want to know what the minimum impedance dip for each speaker is and use that as the baseline to calculate the load. OTOH, your Aragon is a beast. I seem to recall it had the ability to drive Apogee Chinchillas with ease and would mock your question if within earshot. That is when it takes a break from driving dead shorts for amusement.
vintage 5.0
vintage 5.0
Thanks for the responses. That is what I like on here so much knowledge and guys willing to share it. The two sets of speakers are M@K S-1B and Sonus Faber Concertino.
You will probably have to try it and see. Note if they are vastly different in sensitivity they will play at different volumes. And if they are both low sensitivity you will have to crank up the volume higher than you would with higher sensitivity speakers. So it kinda depends on other things besides nominal impedance. Including the type of music and the volume you listen at.
vintage 5.0
vintage 5.0
They actually sound good. The two rooms are attached with a opening that is wide. I can not tell much difference and it sounds great. I just wanted to make sure it would not harm the amp in anyway. It seems to have lots of power.
vintage 5.0
vintage 5.0
I have not had a amp before with this much power so I was just wondering.
Imprecise
Addicted Member
Running a 8 ohm and a 4 ohm resistive load in parallel would give a net resistance of 2.67 ohms. The Aragon 4004 MK II is a constant voltage source down to 4 ohms (that is, twice the 8 ohm power) and is stated to be capable of increasing power output even down to 1 ohm. But keep in mind that speakers are not purely resistive loads. They can be highly reactive and at some frequencies or with some music loads have impedances (resistance and reactance) sometimes well below the nominal rating. However the Aragons are capable of delivering lots of power into low loads and should be just fine with the setup you describe. I do not know the sensitivity of the speakers you are using or how loud you like to play them which would influence things. If you hear really distorted nasty sounding peaks coming out of the speakers at high volume, the amplifier may have gone into clipping. That is not as much of a danger to the amp as it is to your tweeters - gobs of odd order harmonic distortion going way up in the frequency band. But bottom line: if you do not go insane on volume levels, you should be OK.
Always listen for distortion if you have it cranked up, and put your hand on the heat sinks and see how it's doing the first time out with this setup. Make sure the amp has plenty of air around it. If it gets hot, that's a sign. A little hot, maybe a little fan pointed at it. Really hot or distorted sound, cut it back or change the setup. Observe and adjust.
Also bear in mind the quoted 4 or 8 ohms for loudspeakers is a nominal value. Most 8ohm speakers will be down to about 6ohms somewhere in the audio band and 4ohm speakers will usually drop to about 3ohms. In the example given (8 + 4 in parallel), you could end up below 2 ohms - heading for a short circuit. The amp manufacturers are always going to be a bit conservative when giving their limits. They don't like reports of their amplifiers burning out (even if it isn't their fault) because it make for poor customer relations and bad publicity. But, be careful when running low impedance loudspeakers because they can kill amplifiers at surprisingly low volume levels.
savatage1973
Addicted Member
I have two Aragon 4004's and can assure you that you are not harming them. At one one point I was using them to drive Infinity Kappa 9's which drop below a 1 ohm load, and they were not running "stressed" or hot.
vintage 5.0
vintage 5.0
Thanks to all of you that is the info I was looking for. I do not listen to loud music at all. Mostly some country, strings, female vocals and of course some rock. That makes sense to me. I just wanted to make sure I would not hurt the amp or blow a fuse or something. Thanks again that was very good information. Would I be better to run two pairs of 8 ohm speakers?
RTally
Speaker addict
Two pairs of 8 ohm speakers in parallel is a 4 ohm load to the amp. Most good amps are robust enough to hand that kind of load without damage. But it would better if the amp is rated for 4 ohm loads. I believe your amp is rated for loads down to 4 ohms. You would be better off with two pair of 8 ohm speakers.
Imprecise
Addicted Member
The Aragorns he has are actually billed as stable down to 1 ohm, that is, they will continue to produce more power down to that impedance. At 4 ohms they produce twice as much power as at 8 ohms. In other words constant voltage down to 4 ohms. The voltage will drop after that as the impedance drops but the amp should not misbehave. Although as already pointed out by toxcrusadr, the heat sinks should be checked..
savatage1973
Addicted Member
As I have already previously posted, I have two Aragon 4004's and have used them to drive Infinity Kappa 9's (and actually Apogee Divas, as well)--both of which drop to or below a 1 ohm load and they never broke a sweat. The Aragons were primarily designed and spec'd by Dan D'Agostino (of Krell)--often termed as "baby" or "poor man's" Krells, but they are built like tanks and will drive a brick if asked.
My Krell monoblocks (KMA 160's) are factory-rated at 160w each @8 ohms, but also factory-rated at 1280w each @1 ohm, with provisions in the manual to "tweak" the protection circuit to allow them to operate below 1 ohm--basically, you can arc-weld with them.
I honestly don't even see how two pair of 4 ohm speakers would seriously stress an Aragon--from my experience with them.
This Aragon sounds like a beast. Not many amps truly double their output going from 8 to 4 ohms.
Purely for academic discussion, here's the Infinity Kappa 9 impedance curve (found on the web, hopefully accurate).
Really does drop below 1 ohm at about 35 Hz, and again at 7KHz. Yikes. That being said, the load on the amp is not 1 ohm all the time, but only when program material occurs in those frequency ranges. Where most music is, about 80-5k, it's in the 3-4 ohm range. Even without knowing the reputation of Infinity Kappas, looking at this graph, it's a speaker that would stress most amps especially with bass heavy music. Double yikes.
If the Aragon can drive these without breaking a sweat, it's a monster.
Purely for academic discussion, here's the Infinity Kappa 9 impedance curve (found on the web, hopefully accurate).
Really does drop below 1 ohm at about 35 Hz, and again at 7KHz. Yikes. That being said, the load on the amp is not 1 ohm all the time, but only when program material occurs in those frequency ranges. Where most music is, about 80-5k, it's in the 3-4 ohm range. Even without knowing the reputation of Infinity Kappas, looking at this graph, it's a speaker that would stress most amps especially with bass heavy music. Double yikes.
If the Aragon can drive these without breaking a sweat, it's a monster.
vintage 5.0
vintage 5.0
That is so funny my close friend has a set of the Krell KMA 160s those are some serious metal. They get so hot and use some power. I think they are real impressive amps. I bet you like having those around.
savatage1973
Addicted Member
Your friend has very good taste (IMO), but I own 4 of them, so I am biased. Yes--they are "beasts" to say the least--they weigh in at just under 100lbs each, run in pure class A mode, so they do get HOT (even just idling), and draw 8A current each at idle--so yes, they do use some juice.
vintage 5.0
vintage 5.0
He is the guy that helped me get into this hobby. I purchased my Quick Silver tube mono amps from him. He had them for a few years and I told him if he ever sold them to let me know. He finally did and I got them. The funny thing is he had the Aragon I have and sold it to another buddy of mine and I snagged it from him. He name is Mark and he knows alot and used to work in the audio shops in the 70s. His favorite amp guy of all time is Nelson Pass. That is the cool thing in this hobby so many guys with knowledge that will share it.
