First Order Crossovers: Pros and Cons


I wonder if some folks might share their expertise on the question of crossover design. I'm coming around to the view that this is perhaps the most significant element of speaker design yet I really know very little about it and don't really understand the basic principles. Several of the speakers I have heard in my quest for full range floorstanders are "first order" designs. I have really enjoyed their sound but do not know if this is attributable primarily to the crossover design or to a combination of other factors as well. In addition, I have heard that, for example, because of the use of this crossover configuration on the Vandersteen 5 one has to sit at least 10 feet away from the speakers in order for the drivers to properly mesh. Is this really true and if so why? Another brand also in contention is the Fried Studio 7 which also uses a first order design. Same issue? Could someone share in laymans terms the basic principles of crossover design and indicate the advantages and disadvantages of each. Also, what designers are making intelligent choices in trying to work around the problems associated with crossover design? Thanks for your input.
dodgealum

Showing 1 response by applejelly

The exchange between Roy and Golix above leads me to bring up something I have been thinking about for a long time – the phasing of the recorded music before it even reaches your stereo system.

I have read enough about 1st order crossovers and phasing and to convince myself that this design philosophy is valid and this approach is the only one that can achieved a time coherent design. To me the $20,000 question is – does it matter enough to outweigh all the other compromises that speaker designers must make?

Others have asked if time coherence, or lack there of, audible. Let’s assume the answer is yes. The next question, is it preferable? Obviously not to everyone. Many have auditioned Vandersteens, Theils, and Meadowlarks and still chosen other brands.

Time coherence designs with first order crossovers are the only design that can come close to preserving the original waveform, most easily seen by measuring its step response. I totally agree with this. But music is not a square wave, so tracking something that doesn’t exist in natural music doesn’t prove you can make better music. Transients can be sharp, but they are not infinite slop step functions.

Going back to my first paragraph, what about the phasing of the music recorded on that CD or LP? Even if a stereo system from source to speaker was perfectly able to preserve the original waveform, what are we trying to preserve? I know very little about the recording process, but I can bet many an album has been processed by recording engineers in ways that destroys the phasing of the instruments used to make the music. Some genre’s may be better than others. Some studios may be better than others. But how are we, the music buyer, supposed to know if the waveform we are buying is worth preserving? I would love to see some discussion on this HUGE factor. I have read Richard Vandersteen tests his speakers with his own recordings. I am sure those recording have their phasing preserved. But doesn’t this say something about the phasing of recorded music in general?

Finally I would also like to see discussions on the real world trade-offs of using 1st order crossovers. Like small sweet spots. Is that inherent to all 1st order designs or do all good imaging direct radiating speakers have that? And is the sound outside the sweet spot worse for time coherent designs? If so why? I have only listened to Vandersteens (of the 1st order designs) and the difference in sound from sitting in the time coherence zone to standing up is quite alarming. There is something special going on in the sweet spot, but the Vandersteens sound flat when I stand up – treble drops right off. I know they just lost their time coherence, but when I perform the stand/sit test with my home speakers, the difference is far less dramatic. Do 1st order designs sound extra good in the sweet spot and extra bad everywhere else? Comments please.

Other inherent trade-offs of 1st order designs? Thanks in advance.