Newb Question - 4ohm speakers on a 6ohm outputs

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Dksmiley

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Hi Guys

Big sound enthusiast, everything in my car is Kicker and I had a decent Pioneer 2.1 310rms setup at home until I let a little brat into my room and he felt the need to push the cones in all my speakers :facepalm:

I've gotten the cones out with the aid of a little sticky tape, but the left tweeter and right mid are not working after a week of playing :cursing:

The amp is pretty decent and at least the subwoofer wasn't touched.

The long and short of it is I need to replace 2x front speakers. The pioneer boxes are sealed with no way of opening them.

I had old JVC boxes and I have purchased a pair of kicker 2 way 5.25" and fitted them in the JVC boxes and they look and sound awesome, I was going towards crisp highs and decent midrange as I mostly listen to Instrumentals and Youtube covers, guitars and pianos etc.

My concern is should I be worried about the amp melting down or blowing the speakers and is there any way I could correct this efficiently without losing sound quality??

Any assistance would be much appreciated, specs are below.

{Amp Specs}
Amplifier:
- RMS Front: 80 RMS x 2 (6 ohms)
- RMS Subwoofer: 150W RMS (3 ohms)

Sound Features:
- Dolby Digital
- Extra Bass Mode (X-Bass)

Pioneer 2.1 Dvd Mini System - Black | Buy Online in South Africa | takealot.com

{Speaker Specs}

Kicker 40cs54 - 5.25"
4 ohms
75w RMS

https://www.crutchfield.com/S-rVjP7uix7Ux/p_2064CS54/Kicker-40CS54.html
 

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Well, that amp looks like a specialty thing, frankly. you could look around for a low Ohm brick resistor for each speaker positive teminal - of appropriate wattage
 
garww said:
Well, that amp looks like a specialty thing, frankly. you could look around for a low Ohm brick resistor for each speaker positive teminal - of appropriate wattage
Click to expand...
Thanks for the response, am a bit uneducated when it comes to resistors and stuff, do you know the appropriate wattage of the resistor I would need? also think I would be looking for a 2ohm resistor for each speaker?
 
Well, you probably should have ordered 6-ohm, or, 8-ohm speakers. Truthfully, I'd probably run it the way you have it and just not crank it as much. I've run 4-ohm many time, but I had better confidence in the amp. 4-ohm is "close" to 6 ohm
 
I wouldn't do it. 4ohm speakers on 6ohm outputs.
I've used this trick many times with car radio's but then in reverse.
If you put 8ohm speakers on a 4 ohm radio amp you can double the watt's from the speaker. You send out say 45 car radio watt's to an 45 watt's 8 ohm speaker, and you´ll get the sound of a 90 watt's 4 ohm speaker. (i allways blew away my friends with there expencive specialized 300w woofers :laughings: )

So in your case that would be cutting the speaker watt's in half? Needing double the amp watt's to feed the speakers. And as for good sound one wants watt's.... I guess you'll loose deeper bass.
Better do it reverse. So put 8 ohm's on your 6 ohm amp.
 
The speaker ohm is a static measurement, but they can dip all over the place in combination with the music and cabinet loading. The MFG should have a spec sheet with a graph showing the variations. This amp is probably designed just for the included speakers, though. I don't know if it's one amp, or, two amps in there, etc. ?
 
garww said:
This amp is probably designed just for the included speakers, though. I don't know if it's one amp, or, two amps in there, etc. ?
Click to expand...
Thank you all for taking the time to respond :)
@garww it's a single unit hifi, nothing fancy..you can see a picture in the link, just three outputs:
2x80w 6ohm for fronts
1x150w for subwoofer
Watts in rms

I would of ordered 6 ohm speakers but thing is I couldn't find stockists in South Africa let alone 5.25" size in 6 ohm. The speakers that came with the system are sealed with no screw holes to dismantle and replace speakers unless I break the boxes apart.

Kicker were one of the only suppliers that had the size I needed and closest to the wattage the hifi pushes out, and since I have kicker 6x9s, sub and amp in the car I know they're very crisp sounding speakers and good build quality so I thought I would give it a shot.

They sound 10 times better than the original pioneer speakers to be honest, just felt like a shame to toss out a 310w rms amp just because the speakers were wrecked
 
42low said:
So in your case that would be cutting the speaker watt's in half? Needing double the amp watt's to feed the speakers. And as for good sound one wants watt's.... I guess you'll loose deeper bass.
Better do it reverse. So put 8 ohm's on your 6 ohm amp.
Click to expand...
might just give this a try, I'm not too concerned about the bass on these speakers, more mid range and highs, the dedicated sub has more than enough rumble to have my neighbors banging my bedroom wall.lol they hate my car as well :-D aaahhh the joys of life, smiles mischievously
 
Trying is always a good option. Good luck with it!

What i mostly meant is that you probably get an 'empty' sound. You will miss the watt's for power cause your amp needs to give 6/4th so 1,5 times what the speakers ask.
But it can go well if your lucky. Try and you will know.
 
42low said:
Trying is always a good option. Good luck with it!

What i mostly meant is that you probably get an 'empty' sound. You will miss the watt's for power cause your amp needs to give 6/4th so 1,5 times what the speakers ask.
But it can go well if your lucky. Try and you will know.
Click to expand...
I see what your saying now..so my best bet would be try that out, at the moment it sounds good at 15/30 volume, max I've taken it up to was 18 and that's pretty loud, weird tho coz on guitar recordings it plays well but piano recordings seem to have a slight static on certain notes..Also what's a good 4 ohm compatible amplifier you can recommend me that won't break the bank..running sound of my pc, so have optical out available
 
And don't put your volume up at max. As you have differences in ohm's which can conflict slightly it could be that you will run something (in time).
Your amp has to work 1,5 times hard, so your amp's end-chip can burn.
 
The deal with lows ohms is that you inch towards no control over that reactive interaction of amp and driver. 2-ohm speakers require some fancy dancing.from a amp. Pro and Car audio can benefit from higher SPL in the 4-Ohm realm. For more control, you can see 16 and 32-Ohm - like on a Marshal guitar stack. It is the same with headphones. More refined as you go up from 32-Ohm to 600-Ohm
 
Bit "o" history. When the first transistorized amps were produced they were optimized for an 8 Ohm speaker. The most common bog S speakers of the day (in radios etc) were THREE Ohms and use of those would bugger an 8R amp in short order.

Then came (in EU) the DIN 45/4500 "HI FI" specification and that called for FOUR ohm speakers. We in UK could of course still safely use eights but power would be reduced by a bit less than half* . Solid state amps were still a bit feeble (except Quads and pro stuff) but theses days IMHO a rating of 6 Ohms is a peculiarity and not cast in stone and the amplifier will be perfectly safe with 4 R speakers although if you push it really hard you might trigger nasty noises as a VI limiter kicks in.

*Actually, depending upon the exact topology, the OPTIMUM load Z for most sstate amps is in fact close to six Ohms. Indeed at least one speaker mnfctr (Wharfedale iirc) made speakers of nominally 6R Z.

DON'T put resistors in SERIES with speakers! Very bad "fi" !

Dave.
 
Lot of my tube stuff has 8-ohm. I can only think of one thing that isn't marked, over here. Hmm, and I can't recall what's in the Telfunken ? That's, offhand, 6 tape recorder systems and 3 radios from before SS using 8-Ohm. That 15-inch in the tube console was 8-ohm.

I never looked into it, but I have thought 6-Ohm was some easy x-over trick ? 8-ohm dome & 4 ohm woofer
 
Rule of thumb with ohms and amps is that you can use an amp with say a 4ohm rating with an 8 ohm speaker but the amp will produce about a 1/3rd less power, but it is not advisable to load it up too much, say 16ohms, as it will make the amp work hard and heat up.

If you run say an 8 ohm amp with 4 ohm speakers the amp runs what they call cold, strange terminology but I read that somewhere, the amp starts to see this as an open circuit and this will eventually damage the amp.

However speaker impedance is actually a bit flakey, if you measure the ohms of a speaker it is often a bit out and also the speaker ohms changes while in use, possible due to temperature, so running a 4ohm speaker on a 6ohm amp will probably be fine depending on how hard you are driving the amp. My surround sound system has had the wrong ohm centre speaker for about 5 years and nothing has blown up.

Alan
 
Ooo! Some strange ideas about amps, impedance and loading frying about!

Impedance is merely the "resistance" of a speaker to AC signals and since it changes with frequency it can only really be defined as a plot of R against F which strictly speaking is the "modulus" of impedance. To make thing simpler, impedance (Z) is quoted at a specific frequency, used to be 400Hz but might be 1kHz these days. Matters little since modern amplifiers will cope with pretty much any Z so long as it does not fall below the handbook rating. That rating is USUALLY four Ohms for solid state gear but some big Mothers can go as low as 2 R . The OP's amp is "off the wall" with a rating of 6 Ohms and I doubt 4 R will hurt it.

For VALVE OP stages the load should not be more than twice the amp specc'. So, an 8R amp would be happy'ish with 16R OR 4R. The big no-no for valves (aka tubes) is NO load, i.e. an open circuit that will lead to arcing and destroy valves, valve bases, associated circuitry and possibly even the OP traff. Such damage is far more likely with a guitar V amp since they are regularly over driven and voltages can hit a kVolt even under "normal" conditions! Also not advisable to "mismatch" a valve G amp even 2:1 AND drive the breasts off it. Bedroom widdling levels ok.

Yes, speaker Z* increases as the voice coil heats up, can get to nearly twice the cold resistance but it is a time limited effect, the actual "R by t" will be quite short but of course be different for various voice coils as their thermal mass and local cooling varies. (produces "Thermal Compression and valves can beat this far better than Silicon but that is another story!)

* Actually just the "real" part, the DC resistance that increases because Z= root of R sqrd +XL sqrd where XL is the inductive reactance at some given frequency.

Dave.
 
42low said:
I wouldn't do it. 4ohm speakers on 6ohm outputs.
I've used this trick many times with car radio's but then in reverse.
If you put 8ohm speakers on a 4 ohm radio amp you can double the watt's from the speaker. You send out say 45 car radio watt's to an 45 watt's 8 ohm speaker, and you´ll get the sound of a 90 watt's 4 ohm speaker. (i allways blew away my friends with there expencive specialized 300w woofers :laughings: )

So in your case that would be cutting the speaker watt's in half? Needing double the amp watt's to feed the speakers. And as for good sound one wants watt's.... I guess you'll loose deeper bass.
Better do it reverse. So put 8 ohm's on your 6 ohm amp.
Click to expand...
that's not correct at all .... amps put out more into lower impedances ..... without going into the electronics of it just look at the specs of ANY amp ..... if they rate wattages for different loads, the output is higher into lower loads.
 
Lt. Bob said:
that's not correct at all .... amps put out more into lower impedances ..... without going into the electronics of it just look at the specs of ANY amp ..... if they rate wattages for different loads, the output is higher into lower loads.
Click to expand...

What i meant to say in the beginning is that the sound changes.
And correct it is for sure.
What i did in my car was 8ohm speakers on 4 ohm amps, which gave me almost double the sound in good quality. And for that only half the amp's wattage is needed. Were i with 200W/8ohm set easily blew away my friends with there 300W/4ohm set, and that with good quality sound.

So if i reverse that, double the amp wattage is needed to feed the speakers. And as mostly speakers already are of higher wattage as amps are, this problem will only be made bigger, with worst sound in the end (cause the amps can't feed the speakers enough).

Try both options. If the amp and speakers are to far away from each other, you will hear that less ohm speakers won't give a good deep sound (not that big a problem if the amp has enough power).
 
42low, I am pretty sure English is not your first language and so your comments are not coming across very clearly.

Now, what I have to say MIGHT be a challenge to your opinion but it is what I and many top technical people in the industry believe to be the case.

1) Any competently designed audio amplifier OF SUFFICIENT power will sound the same as any other good power amp and that has been accepted for decades. Many times the tweaky, beardy subjectivists have argued "The XYZ sounds thin and distorted. The YZX is smooth and faster" Mind you, they change their preferences every few years about the SAME designs!

2)The sound quality of a loudspeaker is not affected by the impedance chosen. Most "hi fi" speakers are nominally 8Ohms but there are/have been 6R units. One of THE most respected speakers ever made, the Rogers LS35/A was originally at least, 15 Ohms. Some early very HQ speakers were of very complex impedance and a sod to drive. The early Spendors blew one or two "lesser" power amps! Modern amplifier technology at monitor prices and quality levels are virtually bomb proof.

And lastly, the interior of a car is a bloody awful place to judge the finer points of sound! Even if it is not moving (when the noise floor will be about 80dBSPL!) the tiny tin box is not conducive!

Dave.
 
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