3-way vs 2-way speakers. Can 2-way speakers sound just as good as or better than 3-way speakers?

[Mart68]

I meant, the BBC pioneered the use of plastics. Then KEF took over and popularised it, as a two-way mostly. No details covered, the yada yada, there's to much story-telling, interesting, but not quite on topic. (Material science was catchy, psychoacoustics not so much.)

What to lose if the midrange driver was omitted? Can excellence be restored by other means?

Other than using a compression driver that has a much wider useful range? The BMR looked like it might do that but I've never got to hear any of the designs that employed them (Cambridge did a few) and the feedback was lukewarm. Maybe there have been further developments there that I am unaware of.

Of course you can make a two way that has good sound quality. Done that myself. But the thread title asks if a 2 way can be better - I will still stick to my guns and say if all else is equal (and we leave out designs using compression drivers), the answer is 'no'.

 

[Heinrich]

Other than using a compression driver that has a much wider useful range? The BMR looked like it might do that but I've never got to hear any of the designs that employed them (Cambridge did a few) and the feedback was lukewarm. Maybe there have been further developments there that I am unaware of.

Of course you can make a two way that has good sound quality. Done that myself. But the thread title asks if a 2 way can be better - I will still stick to my guns and say if all else is equal (and we leave out designs using compression drivers), the answer is 'no'.

As said a few times before, even by others indirectly, the midrange driver would isolate the mids from the IM distortion (in parts induced by Doppler FM) induced by the bass. To recover from that would need an exceptionally expensive bass/mid driver, but would reach only so far.

A safer bet is a well designed bigger bass/mid, again expensive by its nature. Say a sole 10" replacing a 7"+ mids combo. In regard to IM that's not an exaggeration. (People should learn about IM more.) The data shows it all too clearly, e/g on some YT channel that provides the data; compare the typical 2-way w/ a 3-way, even the deservedly well regarded Neuman 2-way monitors confirm the stated hypothesis.

Of course, the bigger box for the 10" would provide bass w/ more max spl, is more effective, or would go deeper, all as an additional benefit--if the IM wasn't in focus. You know, what (hard) limit is exceeded first. If one want's to keep the low(er) IM of a 7"+ mids combo as a three-way, the 10" would be a just good enough replacement.

The latter will again narrow down the dispersion pattern, because the necessary match between big bass/mids versus small tweeter will ask for a waveguide/horn for a variety of reasons.

 

[Chromatischism]

The ideal is to smoothly cross to a subwoofer between 60-80 Hz so there is never too much IMD to begin with. Such a system will blow any speaker trying to do sub bass out of the water.

 

[Heinrich]

The ideal is to smoothly cross to a subwoofer between 60-80 Hz so there is never too much IMD to begin with. Such a system will blow any speaker trying to do sub bass out of the water.

You didn' t follow the hint to inform yourself on IM (multitone distortion, basically), using media like youtube with some certain contributors. Nope, again a myth that such a low cross-over would solve the problem of the little ones. It needs a bass plus a dedicated midrange driver to gain roughly 10dB plus. Means for a given tolerable IM the spl of a 3-way is 10dB higher than that of a 2-way--mostly regardless of size, or refined tech/!

And psychocoustics is another perspective. IM distortion looks like that, given a modulator of Flow and a modulated Fhigh:
spectr = Flow + Fhigh+ ( Fhigh +/- n * Flow), n = 1, 2, 3, ...

With a low Flow the disturbing componets are close to the Fhigh, and hence might be masked by the Fhigh. A sub that covers only the very lows might not be as effective as it first seems. From my anecdotal investigations, taking me myself as the lab rat, I would conclude that the notion is valid.

 

[dfuller]

The ideal is to smoothly cross to a subwoofer between 60-80 Hz so there is never too much IMD to begin with. Such a system will blow any speaker trying to do sub bass out of the water.

To be clear, this depends heavily on the speaker in question. A little 2 way 5" coax will still be pretty rough crossed at 80hz.

 

[Chromatischism]

To be clear, this depends heavily on the speaker in question. A little 2 way 5" coax will still be pretty rough crossed at 80hz.

Of course. That's why I wouldn't build that speaker.

 

[NTK]

They say a picture is worth 1000 words ...

View attachment 476654

Whoever produced these plots (KV2 Audio?) needs a crash course on line array theory.
https://engineering.purdue.edu/ece40020/Homework/SomeRefs/Line_Array_Theory.pdf

 

[Heinrich]

Of course. That's why I wouldn't build that speaker.

Examples from Erin (won't steal the plots alone), see the multitone distortion, scroll down:

The beloved by so many KEF LS50 won't be rescued by a 80Hz sub, it needs a true bass, 1kHz range is massively affected:

KEF LS50 Meta Bookshelf Speaker Review

Kef LS50 Meta

www.erinsaudiocorner.com

Same with a 2-way in the 5k/pair bracket (lol):

Radiant Acoustics Clarity 6.2 Bookshelf Speaker Review

Kanto YU4 Speaker

www.erinsaudiocorner.com

Compare to a mediocre 3-way:

Wharfedale Super Linton Speaker Review

Wharfedale Super Linton

www.erinsaudiocorner.com

Compare to a not so well done3-way, mid-driver sets in too high (1k):

Wharfedale Super Denton Bookshelf Speaker Review

Wharfedale Super Denton Bookshelf Speaker

www.erinsaudiocorner.com

Finally see what's possible in the wider 5k/pair bracket:

Arendal 1528 Monitor 8 Review

Arendal 1528 Monitor 8 Review

www.erinsaudiocorner.com

Alas, I've not found any 2-way w/ bigger bass/mid.

The method of multitone has its caveats, as spectrum is unweighted etc, Erin's arrangement might be affected by microphone's own IM etc. Still, at least there's a clear trend.

 

[bmc0]

spectrum is unweighted

I believe the multitone stimulus has a "pink" spectrum (-10dB/decade). Or did you mean something else?

 

[a4eaudio]

Harmonic distortion, intermodulation distortion, crossing over in the sensitive region, etc., etc.

So let's eliminate those reasons...Why would a three way (with attached woofers that are likely not in the optimal room location) sound better than a 2-way with Bliesma tweeter and 5" Purifi woofer crossed at 3kHz, with 2 to 4 subs actually placed where they overcome room nodes? If you want to argue max SPL make it an MTM with dual Purifi drivers.

 

[levimax]

Harmonic distortion, intermodulation distortion, crossing over in the sensitive region, etc., etc.

So let's eliminate those reasons...Why would a three way (with attached woofers that are likely not in the optimal room location) sound better than a 2-way with Bliesma tweeter and 5" Purifi woofer crossed at 3kHz, with 2 to 4 subs actually placed where they overcome room nodes? If you want to argue max SPL make it an MTM with dual Purifi drivers.

Integrating subs is not as straightforward as advertised. It is much easier to integrate a woofer and a mid in the same enclosure where the engineers know the distances and driver parameters and accurate measurements can optimise the integration much better than randomly separating the drivers in a random room and then taking inherently flawed in room LF measurements and trying to integrate them. In addition the audibility of room modes is not settled science, peaks can easily be attenuated with minimum phase filters and the audibility of dips in LF response is much less than their visual impact would lead you to believe. The best is always going to be mains as full range as possible with subs added and carefully integrated if needed.

 

[kharan]

Harmonic distortion, intermodulation distortion, crossing over in the sensitive region, etc., etc.

So let's eliminate those reasons...Why would a three way (with attached woofers that are likely not in the optimal room location) sound better than a 2-way with Bliesma tweeter and 5" Purifi woofer crossed at 3kHz, with 2 to 4 subs actually placed where they overcome room nodes? If you want to argue max SPL make it an MTM with dual Purifi drivers.

That's a lot of things to eliminate. But let's say we can magically do it.

Then we'd still have issues with output capability, a 6.5" let alone a 5" can't get to the usual sub crossover frequency of 80 Hz at high SPL, it works well enough in a situation where a bookshelf is enough, but not in larger living spaces. You could cross higher, and subsequently loose the freedom of placement of the subs. In this case, you find yourself with a three way again.

And also, the better solution would be three way with subs.

To be frank, if you want to stick with two ways, a small bookshelf isn't the best way to go. Some kind of constant directivity horn crossed low that matches directivity with a large-ish woofer is a more performant solution that allows much more flexibility.

 

[a4eaudio]

Integrating subs is not as straightforward as advertised. It is much easier to integrate a woofer and a mid in the same enclosure where the engineers know the distances and driver parameters and accurate measurements can optimise the integration much better than randomly separating the drivers in a random room and then taking inherently flawed in room LF measurements and trying to integrate them.

Why would you randomly separate drivers in a random room? If you had a high performing two-way with Purifi woofers, why not strategically place subwoofers in your specific room?

In addition the audibility of room modes is not settled science, peaks can easily be attenuated with minimum phase filters and the audibility of dips in LF response is much less than their visual impact would lead you to believe. The best is always going to be mains as full range as possible with subs added and carefully integrated if needed.

This has as much scientific weight as me saying "the best is always going to be two-way mains with subs added and carefully integrated".

 

[a4eaudio]

That's a lot of things to eliminate. But let's say we can magically do it.

Don't need magic. I specifically listed 5" Purifi drives to avoid the harmonic distortion and intermodulation distortion argument. And specified the 5" so it could cross at 3kHz, as some have mentioned the horrors of crossing over between 300Hz and 3kHz.

Then we'd still have issues with output capability, a 6.5" let alone a 5" can't get to the usual sub crossover frequency of 80 Hz at high SPL,

Nope, the Purifi driver will have no problem reaching 80Hz. And I mentioned using two 5" Purifi drivers if needing high SPL.

 

[kharan]

Don't need magic. I specifically listed 5" Purifi drives to avoid the harmonic distortion and intermodulation distortion argument. And specified the 5" so it could cross at 3kHz, as some have mentioned the horrors of crossing over between 300Hz and 3kHz.


Nope, the Purifi driver will have no problem reaching 80Hz. And I mentioned using two 5" Purifi drivers if needing high SPL.

I don't know about you, but I'd rather get this

than this

Both Purifi, 10" vs 5.25".


MTM has its own set of issues.

 

[Heinrich]

I believe the multitone stimulus has a "pink" spectrum (-10dB/decade). Or did you mean something else?

I use REW, that distributes the components with equal weight over all the spectrum. I would opt to have at least a 10dB bass boost to mimic contemporary popular content.

... specifically listed 5" Purifi drives to avoid the harmonic distortion and intermodulation distortion argument.

See also

Radiant Acoustics Clarity 6.2 Bookshelf Speaker Review

Kanto YU4 Speaker

www.erinsaudiocorner.com

which uses a Purify driver showing impressively low IM ... until it reaches 1kHz. Only slightly mitigated by cutting off the lows.

 

[levimax]

Why would you randomly separate drivers in a random room? If you had a high performing two-way with Purifi woofers, why not strategically place subwoofers in your specific room?

When you buy a well designed full range speaker the driver integration has been done by professional engineers using accurate measurements knowing the drivers parameters and driver distances and using advanced design tools and a lot of testing. When you buy a speaker and a separate sub(s) all bets are off. You are in essence trying to be a speaker engineer but without accurate measurements or tools. By separating the subs and mains you eliminate the possibility of stereo bass and the possibility of using linear phase crossovers. It might work out OK but most likely it will be compromised. In my experience starting with full range speakers and DSP and then adding sub(s) if needed (often times they are not) results in a easier and more successful result. YMMV.

 

[Chromatischism]

Harmonic distortion, intermodulation distortion, crossing over in the sensitive region, etc., etc.

So let's eliminate those reasons...Why would a three way (with attached woofers that are likely not in the optimal room location) sound better than a 2-way with Bliesma tweeter and 5" Purifi woofer crossed at 3kHz, with 2 to 4 subs actually placed where they overcome room nodes? If you want to argue max SPL make it an MTM with dual Purifi drivers.

It definitely won't.

Integrating subs is not as straightforward as advertised. It is much easier to integrate a woofer and a mid in the same enclosure where the engineers know the distances and driver parameters and accurate measurements can optimise the integration much better than randomly separating the drivers in a random room and then taking inherently flawed in room LF measurements and trying to integrate them. In addition the audibility of room modes is not settled science, peaks can easily be attenuated with minimum phase filters and the audibility of dips in LF response is much less than their visual impact would lead you to believe. The best is always going to be mains as full range as possible with subs added and carefully integrated if needed.

You're making this out to be harder than it needs to be. I've integrated many subs. Nothing is "random" about sub bass. You will always be hamstrung trying to create the sub bass from the same speaker box because it is stuck in position. You are left with no opportunity to deal with the standing wave physics of the room. This is what people who are only looking at speaker builds in terms of "what can we fit in the box" are missing.

When you buy a well designed full range speaker the driver integration has been done by professional engineers using accurate measurements knowing the drivers parameters and driver distances and using advanced design tools and a lot of testing.

The problem is those engineers cannot really complete the process because they don't know the environment the speaker will be played in. Sub bass frequencies are a different animal than the rest of the range and need special consideration. Specifically, on-site.

Of course, the only downside to this approach is that you can't just hook it up to any two-channel source without the supporting electronics.

If we are not allowed to have a separate subwoofer box and must get everything from a single enclosure, then in theory, there is more headroom to get the best sound out of a three-way. But if someone will be tempted to take advantage of that three-way design by using a large woofer and extending the bass to 30 Hz, know that it will be physically limited in terms of both output and by room physics.

 

[a4eaudio]

When you buy a well designed full range speaker the driver integration has been done by professional engineers using accurate measurements knowing the drivers parameters and driver distances and using advanced design tools and a lot of testing. ....

Ok, I'll concede...if you buy a well designed speaker done by professional engineers using accurate measurements knowing the drivers parameters and using advanced design tools it will be better than a poorly designed speaker done by amateur engineers using inaccurate measurements not knowing the drivers parameters and using primitive design tools. But why would a three-way fall into the first category and a two-way in the second. (Think March Audio Sointuva vs Borresen X3)

 

[levimax]

Ok, I'll concede...if you buy a well designed speaker done by professional engineers using accurate measurements knowing the drivers parameters and using advanced design tools it will be better than a poorly designed speaker done by amateur engineers using inaccurate measurements not knowing the drivers parameters and using primitive design tools. But why would a three-way fall into the first category and a two-way in the second. (Think March Audio Sointuva vs Borresen X3)

The whole 2 way vs 3 way argument does not make a lot of sense to me. Since I am a full range speaker fan I guess it is easier to make a full range 3 way but there are some great 2 way full range speakers certainly.

My main point is I don't think sub(s) are a great way to add LF extension which I think is better done by the mains and DSP. Subs can help with room modes but I am not convinced that is as big a deal as advertised. I have recently experimented with near full range mains and one, two, and four subs with both DIRAC DLBC and manual integration with REW. I ended up with 2 mains with 2 colocated subs ( in essence 2 full range mains). I found that for me accurate time alignment, not summing to mono, and using ERB smoothed measurements for creating light handed DSP corrections, sounded better than the much smoother measuring 4 sub DIRAC DLBC solution. YMMV.