Are first order crossovers best?

Brianmgrarcom...Take a look at the schematics for first and fourth order X/O, and think again about which is more difficult and expensive to design and build. However, your comment about having fewer components in the signal path is very valid. IMHO this, rather than phase issues, is the chief advantage of the first order X/O.

I have a hunch that manufacturers who use first order crossovers, often for very good technical reasons, feel vulnerable to accusations that they are looking to save cost, and respond with marketing hype and the suggestion that their crossover design involves some mysterious art.

Crossovers are a necessary evil. Even the so-called "full range" drivers have crossovers...mechanical crossover that causes only a small section of the cone (sometimes a separate section called a "wizzer") to vibrate at HF. The only truly crossover-free driver is an electrostatic.

Thanks Eldartford, I hope I made it clear enough in my post that I am not making comments of any great authority of my own, just some things I was told and/or picked up. I was simply told that it is harder to do a first order cross over correctly than higher order, if that isn't the case I am fine with that, but it would beg the question, why don't more manufacturers do first order cross overs. (Another "thought", is it possible that schematics for a high order cross over looks more complex, but it is actually harder to get the same result with less parts, therefore in the end the one looks simpiler but the road to the result was just the opposite?)

"However, your comment about having fewer components in the signal path is very valid. IMHO this, rather than phase issues, is the chief advantage of the first order X/O."
Eldartford, i think that you are discounting the merits of 1st order x/o far more than you should. (LOL! you could accuse me of the opposite! Anyway, w/o meaning to take a pot-shot @ you; rather, to have a meaningful discussion...) there is a definite merit to using 1st order x/o circuits in a speaker that has to do w/ better preservation of phase compared to a 2nd, 3rd, 4th & higher order x/o ckts. your statement of 1st order x/o ckts having a phase shift is very true but what you forgot to write was that 1st order x/o ckts are the only ckts that maintain a constant phase over freq. No other higher order x/o ckt has this feature. it is also true that a 4th order x/o ckt yields a 360 degree ph shift, which can be equated to a 0 degree ph shift but the key here is to realize that in the 4th order x/o ckt, the phase shift between tweeter & midrange & woofer is 0 degrees *only* at the x/o frequency. at all other freq above & below the x/o freq, the ph shift amongst these 3 drivers varies i.e. it's not constant. this is *unlike* a 1st order x/o ckt (which maintains a const ph shft above & below the x/o freq). That Rod Elliot paper I provided a link to describes this very well. IMHO, it is this preservation of ph shft across the freq band that makes music thru a 1st order x/o speaker sound far more real than one w/ a higher order x/o.

"I have a hunch that manufacturers who use first order crossovers, often for very good technical reasons, feel vulnerable to accusations that they are looking to save cost, and respond with marketing hype and the suggestion that their crossover design involves some mysterious art."
it is possible that they do cover up w/ some marketing hype. however, i do feel that few people in the audio manuf industry understand how to correctly implement a 1st order x/o speaker. there is much skill needed. IMHO, you might be discounting their talent a bit too much. maybe you have some experiences that lead you to believe that 1st order x/o speakers are all hype? you seem to be jaded? or, is it typical cynicism from an engineer?

"....but it would beg the question, why don't more manufacturers do first order cross overs."
there might be several reasons for this. I can shed light on 1-2 that *I* think are the reasons. it is only quite recently that well-made drivers have become available. i define "well-made drivers" as those that have a wide(r) range of operation such that they can be x/o at reasonably high freq. For example, the 10" Audax woofer in my 1st order speaker is x/o at 350Hz to the midrange but the woofer has a flat response upto nearly 1 octave higher. this has allowed the speaker designer to make a true 1st order x/o speaker 'cuz @ the x/o freq only the electrical network kicks in & the driver roll-off due to its mechanical structure has not yet kicked in. Most drivers in yester years did not have such performance. Thus, they were not true 1st order x/o speakers - @ the x/o freq they had the 6dB/oct roll-off from the electrical netwrk + the 6dB/oct roll-off from the physical driver. so, they were, in effect, 2nd order systems.
2ndly & related to the above reason, it is only very recently that drivers are better able to handle more spurious power. by this I mean that in a 1st order x/o, the roll-off slope is very shallow (6dB/octave) so a considerable power leaks into the adjacent driver (woofer's power into the mid & mid's power into the tweeter). with the advent of better power handling drivers, the speaker designer is better able to make a speaker that can play at reasonably high volumes. Even then, a 1st order x/o speaker cannot play all that loud. For example, the woofer in my speaker compresses at 105dB SPL. Quite loud but way softer than a 4th order x/o speaker of the same physical size & power handling. So, if one wants to play rock at paint-peeling loud volumes, this is not the speaker. Several users do not like this short-coming. the slope of a 4th order x/o is much steeper & the power leaked into adjacent drivers is significantly less.
Aside from this, if you read the Rbischoff thread that I provided a link to, you notice that a 1st order x/o speaker does have to deal w/ "comb" effects i.e. periodic nulls created in the space surrounding the speaker. i believe that every speaker design has to deal w/ this but, it's my understanding that, in 1st order x/o speakers this effect is worse.
Additionally, improper implemented 1st order x/o speakers seem to have very poor vertical dispersion so that if you stand up from your listening seat, the 1st order magic sound is lost. it takes some skill to minimize (or even eliminate) this effect.

Eldartford, while obviously somewhat esoteric I think the original Walsh driver Ohms could be included with ES drivers as being cross over free. As you said (and I completely agree) that cross overs are a necessay evil, even ES drivers have limitations with regards to frequency range at typicaly desired volume levels. On another note when do we seperate mechincal from electrical cross overs?

Bombaywalla...The link you provided looks interesting, and when I have time to spend I will study it. However, I must dispute your suggestion that the phase difference between drivers in higher order X/O does not remain constant at frequencies away from X/O. A second order X/O is basically a series connection of two first order X/O, and what works the first time does also the second time. A Crown professional electronic X/O that I keep around for experiments is 18 dB/oct, and has a comprehensive manual that shows graphs for both amplitude and phase response for various frequency settings. 270 degree phase difference exists at all frequencies (as I would expect).

My main speakers are Magnepanar MG1.6, and the high pass filter is first order. The low pass is second order, and the break frequencies are significantly different. Of course the Maggie "driver" is quite different from the common cone driver, but it all goes to show that a X/O network can be taylored to the characteristics of the drivers used.

I also use an electronic X/O for subwoofer/main, and it is fourth order. In prior systems, where the main speakers were biamped I have had excellent results with fourth order.