April 2020,

 

Why do I like 4-way and 5-way speakers, better than 2-way and 3-way?

 

Mainly because they’re significantly better, and represent much less overall design compromises.

 

In my younger years, I chased after witches and owned Fostex full range speakers.

I built back loaded horns to “help with bass” and never achieved any satisfactory results.

I then moved on to better grade drivers and purchased a Lowther DX3, and later upgraded it to an EX4.

I'm telling you the EX4 upgrade was well worth it over the DX3, but overall, unacceptable issues were still present.

​

After years of frustration, I finally smartened up, and sold the Lowthers. GOOD RIDDANCE, I should have done that sooner.

No point to try AER or Feastrex, single-way is single-way way still single-way, and it’s will never work.

 

-----------------------------------

 

The two biggest drawbacks in 4-way and 5-way systems is the price and complexity... that’s all.

If you want the best, you have to be ready to pay for it.

“Pursuing the ultimate two- way system” is an oxymoron.

It’s like the expression “military intelligence”. Another strong oxymoron.

I should know… I have 15 years of military service as I write this :)

 

Back to the 2-way oxymoron. I can't think of a single two-way I’d see myself living with, bar none, regardless of price.

That includes the Legendary JBL M2. (active and DSP enabled loudspeaker, shown on left)

 

The single 15” woofer of the M2 is guaranteed to be insufficient in the low bass and lacks ultimate slam ability. The clever D2 double annular compression driver won't come close to reproducing treble like a dedicated super tweeter could.  An 800 Hz crossover point is on the high side considering a 15" woofer transition. a 15" woofer has a heavy cone compared to a 10" mid-range, often in a factor of 4:1. If a lower crossover point were to be used, the compression driver and horn combo couldn't keep up down low. Compromises were clearly made in the M2. Even JBL can't beat physics.

 

----------------------

​

In the 3-way direct radiator category, there’s a select few I kind of like: (may add some later)

• The ATC SCM100A would be one of them.

• The ATC SMC40A (not as refined as the 100A, but much cheaper)

• The PMC BB6-A .

• Jean Maurer 370E (I heard them a very, very long time ago but have fond memories of them. If heard again today, they may be cut from my list as my standards have refined since then, take this one with a grain of salt)

 

The first three mentioned are active (hint), and all use the superb 3” dome mid-range. (Jean Maurer use an affordable Scan Speak Discovery 2" dome mid-range)

ATC use the ATC SM75-150 and PMC use the Volt VM752. Not cheap drivers by any means. (Street price is $700 each)

I always prefer a metal tweeter over a fabric one, but to match those gorgeous 3” textile mid-range dome sonics, the fabric tweeter choice is often the best compromise.

 

Like the JBL M2, the PMC and ATC rose of a single "small" woofer won't cut it for me, but I had to come up with something, I really couldn’t think of anything else that was worth mentioning. And still, with those PMC and ATC, a dedicated subwoofer would be required for serious results.

​

​

Anything that uses a 1” tweeter and a 6” woofer has so many issues in the transition zone, that listening to them is near impossible.

​​Also note than none of the previously mentioned loudspeakers use a Beryllium tweeter. Beryllium has its place later, but just not in a three-way configuration.

 

Note that in 3-way systems, horn category choices are even thinner.

The reality is that horn systems really start to be interesting once you move into four-way and five-way designs.

But here are two choices that always has me smiling: (and a potential third one)

• The Avantgarde Duo Mezzo HD (great, but a super tweeter would bring them to a higher level)

• The JBL Synthetis K2 S9900 (I’d take these over the M2 any day, but never heard them side by side, so show condition could have influenced my opinion here)

• The JBL Everest D67000 (never heard these, but this is a solid design that packs absolute best quality Beryllium compression drivers. They must be very good as the potential is 100% there, and the double 15” woofers are a must for real dynamics. The biggest potential drawback is the passive crossover implementation. One can ruin a speaker right there. Active would be the real McCoy here but hey…JBL choose passive only for these and who knows how good of a job they did.

 

--------------------------------------------

​

4-way and 5-way advantages: (and hopefully competent engineer design rule)

1. Utilize drivers only in their piston range (that means narrower pass bands for each driver)

2. Have nicer and more uniform off axis behavior

3. Obtain much better transition between drivers (matching a 1” tweeter to an 18” subwoofer will be a disaster).

4. Closer spec drivers will integrate better. Always try to remain constant. A plastic (often called "polymer") mid-range mated with a paper woofer and a titanium tweeter, will share very incompatible sonic behaviors, rendering successful subjective integration almost impossible.

 

Think of a classic  6+1 configuration (6” mid-range and 1” tweeter)

This is what B&W 800 flagship series have. Very sad indeed.

At the crossover point, you have a relatively high mass of a speaker cone reproducing the sound and then transfer the duty to a feather weight mass of the 1” tweeter.

Tweeter mass is usually in the 1/4 to 1/2 of a gram while the 6” mid-range is often about 10 grams (a quality Scan Speak 15M8631 cone weight 10.9 grams for example). An average weight ratio of 30:1, which is not ideal for matching sonic characteristics.

If you use a Ribbon tweeter, the mass is even less, like 1/10 gram for an approximate ratio of 100:1... It won’t work. Never will.

​​

-------------------------------------

​

Side note: The moving mass of the previously mentioned 3” mid-range dome of the ATC and PMC speakers is only about 2.2 grams... No wonder the mid-range integrates very well with the 1" tweeter, as the weight ratio being only 10:1. Matching between driver is of uttermost importance.

 

---------------------------------------

​

Back to our 6" mid-range (or mid-bass if talking of small bookshelf's, as examples are plentiful)

The 6" mid-range should be limited to about 2800 Hz upper frequency. This is because they’ll beam above that, and break rule #2

​

Most, if not all 6" paper mid-ranges do not even operate as a pure piston at that point, thus breaking rule #1

Using a lower crossover point is often wise, depending on mid-range quality but then, the tweeter will become the new bottleneck. Compromises never stop with the "6+1" approach.

The above Scan Speak 15M8631 quits piston range and enters break-up mode strongly at only 1100 Hz. Not easy to work with if you ask me, and fully breaking rule #1.

​

A metal cone mid-range like the Seas 15WCY would fare much better, surely up to 2000 Hz, but the metal cone of the Seas will have an immense break-up mode at 9 kHz. This will require serious (complex and steep) crossovers to have any hope of working. And I'm not sure the Seas 15WCY is acting like a piston at 2800 Hz, which is really not perfect either.

 

Still, a good rule of thumb is to use 2800 Hz as the usual sweet spot for most quality cones (6" size) mid-range to 1" tweeter transition.

 

2800 Hz is kind of high for a 6” but this is the reality. Lower crossover points are more desirable, but require a very serious 1" tweeter if a second order passive crossover is used. Most budget tweeters won’t be able to play that low even at moderate SPL. Too high of a crossover point and the mid- range can't keep up, and too low of a point and the tweeter starts to cry.

 

An alternative to our stalemate would be to use a bigger tweeter. A bigger tweeter would play lower and bring a lower transition point feasible.

A Seas excel T35C (big 1.5" dome tweeter) would easily play as low as 2200 Hz, but the price to pay is that those tweeters don’t reach 20 kHz. One would have to use a second tweeter above of the T35C, or forget the goal of 20 kHz full audible frequency reproduction.

Again, gain here and loose there... a lateral move.

​​

An alternative to this stalemate is to use a smaller mid-range.

This will result in a sideway move like the bigger 1.5" tweeter option does. If one would use a 3" mid range instead of a 6", the transition difficulty will be shifted to the 3" mid-range, to let’s say a 12" woofer, won't work. You would have to bring a 6" or 8" low mid-range into the mix, as a single 3" driver won't move enough air to play at realistic levels in the lower mid range region.

​

Our two alternative solutions to solve the "6+1" problem involve adding an extra driver to separate the task even more.

The best choice is to forget the "6+1" and go with three drivers instead of two, but it does increase the cost and complexity.

 

---------------------------

​

Side note:  one perfectly acceptable solution for the "6+1" dilemma actually exists. 

Most high-end manufacturers choose to ignore it, but it does work perfectly.  It involves the use of horns.

Enter the "6+1" design that works. Mount the 1" tweeter into a horn that would permit a lower crossover point to be feasible.

I own a pair of affordable JBL 306P bookshelf monitor using a "6+1" design.

Yet, the crossover point is at an astonishingly low 1425 Hz. What the heck is going on here? 

They can accomplish this feat by using a steeper than normal, 4th order crossover and load the tweeter with a horn, to augment its low frequency output.

My gosh does it ever work :)

It also respects the first two rules described above. However, rules 3 and 4 aren't respected  in the 306P case. (budget product after all)

​

In the high-end commercial product, YG Acoustic Sonja and Revel Performa 228Be use such an approach.

With a less aggressive horn profile (compared to the JBL 306P, the YG and Revel tweeter horns provide less gain) 

The Revel uses an 8" mid-range while the YG choose a double 6" in MTM configuration.

Due to a gentler horn profile, the crossovers aren't as low as the JBL 306P at 1750 Hz and 2100 Hz respectively.

They too respect the first two rules, while leaving rule 3 and 4 open for debate. (I veer towards No)

​

-----------------------------

​

For the remainder of the "direct radiator" camp, solving the "6+1" dilemma means entering in four-way design.

 

One of my favorite direct radiator speakers of all time is the Marten Coltrane Momento 2. (4-way speaker priced like a house)

https://www.marten.se/products/coltrane/coltrane-momento-2/

 

Heard them few times, and they’re always great for what they can do. The mid-range and top end are where they easily outshine all badly designed Wilson audio XLF, and other “cost is no object” speakers like the B&W 800's.

​

The MCM2 uses a single 3/4" tweeter for maximum HF extension (better than a heavier 1" tweeter), a single 2" high-mid for good transition and a regular (very high quality) 7" mid-range to maximize SPL capacity and efficiency (instead of a classic 6" for example, they can afford to use a bigger 7” drivers because of the extra 2” high-mid range transition. This brings a lot of advantages, respecting all four rules above).

​

All three drivers operate within their true piston range and the overall sound is about unmatched. The addition of the 2" high mid-range is what makes the magic possible. One extra step matters a lot!

Only then, the MCM2 use six 8" woofers for bass duty (I would had used 11" woofer, the biggest size Accuton offers, but I assume they wanted to maintain a small footprint. The 8" too are in their piston range)

Note that the MCM2 needs a sub-woofer. Every system does anyway. In fact, they aren't the best in bass IMHO, but they still hold their own with high composure.

 

Other 4-way and 5-way direct radiators I like are: (like the MCM2, they all use three upper end drivers and are intelligently designed)

• Tidal La Assoluta (5-way WWMTMWW style, use a Diamond diaphragm, better than beryllium)

• Vivid Giya G3 (4-way, great but badly need extra sub woofers. This would bring them to be 5-way. They have a stunning sound stage every time I hear them). While they do not reach the resolution level of the MCM2 or the Tidal, they cost far less and are still VERY good.

• PMC Fenestria (need extra subwoofers as well. Sound great but not as good as the above 3. Cheaper price point, has better bass than the G3 due to more woofers)

 

In the Horns category, choices are easier. (both use beryllium tweeter)

• Cessaro Beta II (five-way full horn loudspeakers. Loved them VERY much at Munich High End 2019 show. I’d pick them above any direct radiator design mentioned above, including my venerable MCM2)

• Living Voice Palladian (five-way loudspeakers costing lots of money and having flawless construction, high WAF. Great sound as well but Cessaro is better IMHO)

 

 

Did I forget to mention the Magico Q7, The Focal Grand Utopia, the B&W 800, or Wilson Audio XLF Alexandria?

Nope, they just don’t come close to making the short list :)

​​

​

​

​

------------------------------------------------

 

Personal Note:

It would be extremely pretentious of me to say “my own DIY horn system” is the best. I think it can rival the previously mentioned one on many aspects, beating something here but being beaten on something there.

Audio is very complex, and one can't forget the "I own it bias", let alone the "I built it" pride and much stronger associated bias. (see my page on "I did it, it is good")

​

But my DIY system is not even close to be "apple to apple" comparison to above commercial offerings.

 

Comparisons to the above big 4-way and 5-way systems, my DIY system:

• I have the huge advantage of having eight 18” subwoofers and can obtain real infrasonic bass. None of the above come close to reaching the infra bass I have. None even dream of it.

• Because of my 18” subwoofers, I can choose different bass bin compromises and optimize higher register performance. No need for bass reflex, transmission line or passive radiator and their associated group delays penalties, just to extract few extra hertz of low end. (my bass bin can only reach about 50 Hz compared to the mid 20's or low 30's for the above systems. Not the same design trade off at all)

• My different design goal enables me much different performances. Without the 18 inches subwoofers, my bass bin would have to be very different and wouldn’t perform the way it currently does.

• My system is time aligned. Passive crossover systems can't do that. This brings coherency to an incredible level. This alone can't be understated. (all of the above speaker, on a DIY DSP active setup could get that incredible advantage too!)

• I have a fully active system and use full advantage of DSP correction for all of my 5-ways. If Cessaro was to use DSP and active set-up, their higher quality raw compression driver (all Beryllium) compared to my aluminum ones would be sure to outshine mine. GUARANTEED. I wish I could buy some TAD ET-703’s. I think they alone, cost $5K a pair.

• My room uses lots of acoustic treatment, rendering hotel room show condition not comparable. This is a HUGE FACTOR.

• I use Surround! No 2.0 system can approach multi channel splendid results…never. (see "Munich high end" page)

• My system looks less than “very bad” as my carpenter skills aren't very good, and most of my cabinets are painted with a roller brush!

• I'm not even close to approaching the level of finish quality of an affordable $2500 Kef R300 speaker here. This would assure me that if I was to showcase my system at a show, most people would just laugh, based on the poor looks, and I’d understand that. Audiophiles are incredibly snobs when it comes to look.

• I refuse to spend serious money on finish. Why would I spend $3k to have my cabinet painted in an automotive shop, when it won't improve the sound a single bit. I’d much rather upgrade my drivers or buy a better amp. That what I always do anyway.

​

Later