Crossing Over High Better Than Low?

[Jay]

In my view, the localization issues are secondary to the distortion issues.

True. If the primary issues have been taken care of, what is remain? The secondary issues! In other words, beginners will most likely be busy with the distortion issues while the more experienced ones will most likely be busy with localization, dispersion/lobing, or whatever is secondary.

Most of my solutions using 1" tweeters wind up being around 2.6K. Seems like it is low enough so my mid-base is still reasonably well behaved, and high enough to not cause too much distortion from the tweeter. When my crossovers are done well, I get very good localization.

So localization issues can still be addressed even if the crossover point is high (which is a must for the most driver combination). That's the point.

A major mistake taken by many very smart folks is to focus on a parameter, however real it may be, at the exclusion of far more important ones. Polk, Bose, and Klipsh all come to mind where they went too far on their favorite problem resulting in overall very bad results. The single driver camp premise is the lack of crossover giving better localization at the loss of almost everything else important. Vanderstein takes a more holistic approach, and the results show.

I'm not sure about that. Which one is more important, that could be subjective, depends on taste or objective. If your objective is commercial, you should aim for what is favoured by the target market. And I think Bose, Polk and Klipsch are quite successful.

I cannot see anything wrong also with single driver camp.

 

[whgeiger]

Driver Picking Determines the Rest

Just wanted your thoughts on crossing high (over 5k) vs crossing low (1-1.5k).

For simplicity's sake lets say that we don't want to crossover in 2k-5khz due to the ears sensitivity in this region.

I always thought crossing At 1khz or lower was the holy grail, until i read this information.

"The below pics show that at high frequencies the direction of sound is detected simply by amplitude (loudness) difference between our ears.

At low frequencies the wave lengths are so long that both ears will hear sound at similar level. Therefore below 1K Hz the direction of sound is by the phase difference in the wave between our ears. We are able to detect sound direction to approx 100Hz in a free field. But in a reverberant cave or room this is limited to approx 300Hz because the bass energy is reflected from all directions."

Obviously, crossovers create phase shift. So is it actually better to cross over above 5k rather than below 2k?

Unless you must sustain venue or budget limitations, recommend dividing the audio spectrum into approximately 3 one-decade chunks. Of these the mid range is the most important and may cover a slightly wider range, driver permitting. Speech and most music fundamentals lie in this range where the ears are most sensitive. For crossovers, stay in the digital domain; all modern program sources are there already. Use power amplifiers tailored to match the driver(s) used to reproduce each of these ranges. Ultimately, the drivers selected, will determine the c/o frequencies needed to happily marry them into an enclosure. So pick them wisely.
Regards,
WHG

 

[dumptruck]

Whatever that may be?

Yes, unrealistically extreme examples aside. The hypothesis/approximation/whatever introduced by the OP is that below 1kHz, the brain uses phase differences for localization instead of amplitude. When this is the case (when we want to localize a sound without content above 1kHz), the only way for the stereo illusion to work is to have such phase differences included in the recording, whether that is added artificially, or via the recording method.

Any relative differences between channels on the recording are preserved no matter what the phase error of the speakers looks like. Thus, I think having a crossover below 1kHz does not affect localization, at least as far as that particular issue is concerned.

 

[tvrgeek]

That is IF the brain is sensitive to phase differences. This is under much dispute. The majority of academic papers suggest no. We seem to be amplitude, time and frequency sensitive. The outer ear providing the clues to the horizontal plane. Otherwise you would not know if a sound is coming from in front or the rear. If a very pure tone, you can't! Actually, very pure tones are very hard to localize in any constrained environment. (room)

Back to my basic stance, the crossover point should be selected to best use the drivers selected. It is no coincidence that the majority of 2-ways cross over between 2 and 3K, three ways 500/5K or so. It has all to do with the physics of the drivers, not our hearing. I can get very good localization from my 2-ways.

 

[dumptruck]

Time difference is just a special case of phase difference, for what we are talking about . The effect proposed by the OP involves perceiving time difference, and the idea that phase shift in a crossover region could disturb that perception, which I said I didn't think would happen.

 

[tvrgeek]

Special, yea for a single pure tone! Not what we hear in nature and not germane to music reproduction. I think we do agree, this is not a problem in the top 90% of problems to be dealt with in speaker design. When we resolve the rest, then worry about it.

 

[Jay]

Agree with tvrgeek that the phase shift will be audible, and when everything else has been taken care of then it is the phased shift that is the most critical.

If you know that sharp peak will affect your listening perception, then you will flatten the peak, and you're done, perfect speaker. If you don't know that phase shift will affect your listening perception then you will not do anything about it.

IF you know that phase shift will affect listening perception, THEN you will be ready to learn how to deal with it. Aren't we still far from this?

 

[andy19191]

That is IF the brain is sensitive to phase differences. This is under much dispute. The majority of academic papers suggest no.

Really? Can you please cite any academic/scientific references (not audiophile ones) that show we are sensitive to phase differences?