Why do they still make speakers 4ohm?

Why don't they just make them all 6 or 8 ohm? Easier to drive don't have to worry about the amplifier heating up as much etc.

 

They even make them 2 ohm.

Low impedance may be a deal breaker to you or me, but for most people there are other, more important factors. Quite frankly, I believe the looks, or WAF, is probably the single factor that drives the designers the most. And this is more complex than it appears. For example, 12" and 15" drivers are not used any more for they make speakers too wide.

 

I believe they make 1-ohm woofers and amps for installing in Whump-Mobiles.

Of the dozens of things you worry about when designing a speaker system, the number of ohms is at the very bottom of the list. Some amp have difficulty with a lower impedance, but only a very few of them.

 

What's wrong with 4 ohms? If you were talking about 1 or 2 ohms I might agree. Heck, most cheap receivers have no problems with 4 ohms. Plus in theory, you get double the power out of an amp at 4 ohms vs 8 ohms.

 

Whats wrong with 8 Ohms? Can run 4 8 ohm speakers at same time off most amps using A/B do that with a 6 or 4 ohm and will smoke the amp.

Seems when you go to 4 ohms heat is more of an issues, have to make sure amp can handle it etc. With 8 ohms there no issue. So why not just make them all 8 ohm?

 

Take a poll and see how many people here do that. It's not even a consideration when designing a speaker particularly ones we talk about on this forum.

 

Just say you don't know if you don't know. Lots of people a/b see it all the time.

 

There's really no such thing as a 4-ohm loudspeaker system, anyway. Any practical loudspeaker will show the amp a wide range of load depending on frequency. Your 4-ohm loudspeaker system might present 20 ohms in some places on the frequency spectrum and 2 in others. If the designer has achieved the sound he wants at the component price cost he can live with without putting the system in a phase angle position that's hard on the average amp, he's done his job.

 

I'm pretty sure. It appears you don't.

 

My ex speakers the BW 802D, first year, had ohm swings that caused many problems for some amps. The speakers would go as low as 2 ohms when playing at moderate volume and some amps including my Musical Fidelity kw500 had problems with them. One night I had a nice blue light show when the only tube in the amp went up in smoke. After that I got much more educated about the amp-speaker setup and its possible perils. Take care, John M.

 

It's not as simple as you make it out to be. The drivers used, the design of crossover circuit, the cabinet, ported, sealed, etc. and the goal of the designer all play a factor. If all speakers where an 8 ohm nominal load we'd have missed out on some fantastic sound. You're also ignoring the efficiency rating. You could have an 8 ohm nominal speaker that is rated at 84dB. On the other hand you could have a 4 ohm nominal load rated at 102dB.

No one I know does that and I know a lot of audio people.

 

I drive speakers that dip lower than 2 ohms with a kW500, never had a problem at any volume level.

BTW, there are 2 tubes in it, one for each channel. Most likely, you simply had a tube go bad, it happens.

 

One reason is that lower impedance voice coils are lighter and have fewer turns of wire. Another is that tube amps or solid state amps with multiple taps are a tiny fraction of the market. Most people want four ohm loads.

That said on tube amps with 4, 8 and 16 ohm taps best efficiency is achieved on the 16 ohm tap since all of the secondary is used.

 

Well, I don't know that nominal 8 ohm speakers are inherently easier to drive than nominal 4 ohm speakers. They might be for some solid state amps with current limited outputs, not at all for others and not at all for tube amps with OTs that enable easy matching to 4, 8 and 16 ohm loads.

(Why do manufacturers make 4 ohm nominal speakers? I suspect is just has to do with the drivers they want to use. I suppose if every manufacturer was custom designing speakers to have the voice coils wound to the impedances of their choice they could design speakers to all nominal 8 ohm; or they could limit their designs to using drivers that would enable them to build 8 ohm only systems).

Speakers with relatively flatter impedance curves across all frequencies regardless of whether the nominal impedance is 4 or 8 or 16 ohms are easier to drive. I would think a good design goal for a speaker designer would be to maximize efficiency and minimize big impedance dips and peaks; and a good design goal for an amp designer would be to deliver enough current and dissipate enough heat to drive all but the crazy low impedance speakers.

You could just as easily ask: "why don't all amp manufacturers build amps that don't crap out trying to deliver sufficient current into 4 ohm loads?"

 

Yeah, well, that's a specialty use by a small fraction of the market. Most amps aren't even built for it. You can't expect speaker designers to focus on satisfying a small part of the market with a special need. They're going to focus on they average user.

 

It's largely about perceived volume, cheating with the sensitivity figures, and confusing sensitivity with efficiency.
4 Ohm loads pull more current from the amp, therefore other things being equal, a 4 Ohm driver sounds louder than an 8 Ohm driver....but...

Better voltage sensitivity has to be seen against the increased current, therefore claims of better 'efficiency' are usually false.
The 4 Ohm driver is only more efficient than the 8 ohm driver if it delivers more output for the same current draw.

The benefit of the low impedance loudspeakers being able to play louder is useful for manufacturers of portable audio equipment where voltages are limited, perhaps due to battery operation.

 

Lol, that is why I asked the question. Only attorneys ask questions they already know the answer to.

 

If anyone's that concerned about the amplifier running cooler, buy a 16 ohm speaker system!

 

Many people I know will have 4 speakers hooked to one amp so they have music going in different parts of the house at the same time. Also At least four music stores I know do the same thing.

When I got my outlaw receiver my son wanted to run 4 speakers in the basement (2 rooms) and did. Outlaw say that was not a problem unless one of the pair was 6 ohm or lower. Meaning two sets of 8 ohm speakers would be fine at same time. But a 8 + 4 or 8 + 6 would be bad for the amplifier.

My Sansui AU 717 is rated for 8 ohm load. The Salk speakers I may get are 4ohm. Wondering if that will be an issue.

And Speaker companies must being thinking of nominal ohms when the make one because why are they all labeled 8ohm, 6 ohm etc. I don't see too many 20 ohm or many 1 ohm. Is that just a flip of the coin when they make them? Just by chance its always 8 6 or 4 ohms?

 

Lol, its ok if you do not know the answer. Its like people see something they don't know and rather than not answer they change the subject or answer a question with another question.

 

Yep, but seriously the 4 ohm speaker has design benefits, such as lower crossover component values to achieve the same crossover points, with less phase shift and lower crossover distortion. Tweeters benefit by lower internal inductance and a lower mass voice coil. The 4 ohm speaker system may or may not play louder than an 8 ohm. The science is too intricate to analyze without mathematical language, many factors and variables go into speaker design.

 

So a well designed 4 ohm speaker will have some benefits over an 8 ohm?

 

It's unlikely you'll have any issues with that amp, unless it's not working properly. The power supply is massive. Apparently, the European brochure had a 4-ohm power spec.

jeff

 

Some design benefits, yes, providing they are employed by the builder. Speakers are the most fickle parts of the system. One manufacturer's 4 ohm rated system may or may not sound better than another's 8 ohm system.

Let's assume an 8 ohm system is a simple 2 way design with a nominal crossover at 1.5 KHz. Maybe the 8 ohm woofer rolls off mechanically without any electrical inductor section.. so there will not be any electrically induced phase shift. The tweeter may be crossed with a simple 6 uf capacitor maybe a resistor/LC contour network to help keep lower frequencies out, and its resonant frequency out of range, so the phase angle will be gentle, perhaps 90 degrees at its cut off frequency. The tweeter may wired reverse polarity to keep it in phase with the woofer.

Compare this to a 4 ohm two way system, perhaps a Linkwitz-Riley 4th order crossover, more complex, but benefits by the use of 4 ohm drivers. Maybe this 4 ohm speaker plays louder, maybe a bit more defined in the treble, maybe time aligned. All of this does not guarantee it will sound better than the simple 8 ohm system.

Each system will have its strengths and weaknesses. The 8 ohm system I described may have smoother response, but maybe some coloration in the midrange. Coloration is the byproduct of wide band 1st order crossovers with lots of overlap.. but by clever design can be minimized. The coloration may be imperceptible for some sources, but more obvious for others. The 4 ohm system may sound cleaner and louder per amplifier output voltage, but may exhibit a resonant peak in the treble, more apparent only in certain program. The 4 ohm drivers help to tame "peak-suppressor" resonances by shunting more current away from the secondary crossover components. An LC contour network may be wired across the tweeter in parallel, to absorb the resonant peak. But this adds more components, for better or worse. Nothing is cast in stone for building a great sounding speaker.

As a rule, simple designs with fewer crossover components are easier to drive; More complex systems with irregular impedance curves tax the amplifier.

 

Wonder why the Euro version was spec for 4 ohm while the USA was 8?