Identifying Legitimately High Fidelity Loudspeakers: Myths & Facts about Crossovers

[admin]

The loudspeaker crossover can be considered the brain of the loudspeaker. It directs the bandwidth of frequencies each driver is optimized to reproduce while it also level matches each driver and can help to stabilize the load impedance the amplifier will see. No matter how much science a loudspeaker company may tout leading them to certain design choices, without careful observation of their "science" one cannot be sure of its accuracy. It's easier and often more profitable to justify using cheaper parts or less elaborate design practices than to take the time and do it right. This article explores some of the myths and facts about crossover design. It also discusses some of the mistakes often made by loudspeaker manufacturers done either as cost savings or design incompetence. It is our hope that the reader will gain a better understanding of the mechanics of loudspeaker crossovers so they can make a more informed purchasing decision.


Discuss "Identifying Legitimately High Fidelity Loudspeakers: Myths & Facts about Crossovers" here. Read the article.

[templemaners]

This has been a highly educational and informative series. Keep up the good work!

[GranteedEV]

the first-arrival crowd feels that the on-axis, first-arrival “anechoic” frequency response

Balderdash, says the far-field power response crowd.

In most rooms, it's probably really a combination of both. The axial response does dominate, but the power response still contributes. The first ~5ms will dominate, followed by the next ~10-15ms to stereo imaging , and then the rest afterwards (especially reflections after 30ms) will contribute to spaciousness.

The better crossovers definitely won't assume that the person is listening in a reflection-free environment or even with absorption at the first reflection points - IMO. But unless it's an omni speaker(where the power response will dominate in most setups), the response will be very flat

[gene]

In most rooms, it's probably really a combination of both. The axial response does dominate, but the power response still contributes. The first ~5ms will dominate, followed by the next ~10-15ms to stereo imaging , and then the rest afterwards (especially reflections after 30ms) will contribute to spaciousness.

The better crossovers definitely won't assume that the person is listening in a reflection-free environment or even with absorption at the first reflection points - IMO. But unless it's an omni speaker(where the power response will dominate in most setups), the response will be very flat

Early reflections dominate in small rooms as per Dr. Floyd Toole's extensive research. Of course a speaker exhibiting a smooth and even power response will also likely produce good early reflections since its off axis response is consistent.

[GranteedEV]

Early reflections dominate in small rooms as per Dr. Floyd Toole's extensive research. Of course a speaker exhibiting a smooth and even power response will also likely produce good early reflections since its off axis response is consistent.

The worst thing about a small room isn't even the side wall reflections (they they rarely help at short distances), but the reflection from directly behind you. To compound that, in small rooms people shove their couches flush against the wall.

In such a room with all that comb filtering ( ) then the power response should definitely be good in order to fill in for a lot of the response error.

[gene]

The worst thing about a small room isn't even the side wall reflections (they they rarely help at short distances), but the reflection from directly behind you. To compound that, in small rooms people shove their couches flush against the wall.

In such a room with all that comb filtering ( ) then the power response should definitely be good in order to fill in for a lot of the response error.

Sidewall reflections are beneficial NOT detrimental. I agree most people stick their couches against the backwall which is bad for smooth bass response and a realistic surround field.

[GranteedEV]

Sidewall reflections are beneficial NOT detrimental.

At everyday SPLs Toole's research shows that it seems to help improve intelligibility and give the impression of higher SPL. But are they unequivocally benificial? I think that depends on the distance involved. 2ft, 6ft, 10ft... i'd think each of these distances to the side wall would impact the sound differently.

Anyways I'm probably dragging this off-topic.

[AcuDefTechGuy]

Early reflections dominate in small rooms as per Dr. Floyd Toole's extensive research. Of course a speaker exhibiting a smooth and even power response will also likely produce good early reflections since its off axis response is consistent.

Does that mean even an omnipole speaker could have a good on-axis and smooth off-axis response?

[GranteedEV]

Does that mean even an omnipole speaker could have a good on-axis and smooth off-axis response?

I think so, but its placement would be VERY unique for a lot of non omni instruments to sound good in rooms.

Which is why I think the B&O omnis measure so awkwardly on axis but have a smooth power response and supposedly sound great.

I think omnis are an extreme, just like 45 degree horns in super treated home theaters . You need to find a balance that works!!

[agarwalro]

Balderdash, says the far-field power response crowd. The room reflections etc. are so close in time to the first arrival that they swamp the first arrival completely, leaving the overall far-field energy output of the speaker—the so-called “power response”—as what you hear to determine the tonal quality of that speaker.*

Gene, hypothetically every speaker will have as many power responses as there are rooms. Is there any reference criteria for good vs bad power response? Or, does it boil down to a subjective preference of imaging (meaning good first arrival behavior) vs. soundstage (meaning good room reflection)? (Assuming that said speaker falls into the "accurate" generalization for its near field behavior and listening position or room or media does not favor an overly dead or reverberant space.)

So all those near-field considerations like driver alignment, cabinet diffraction, phase relationships, etc. are far less important in real world listening conditions than their theoretical importance might suggest .

On the contrary, wouldn't these constitute a minimum criteria for loudspeaker quality? It would be a logic defying speaker or "holy smoke magic" conditions in which a poorly designed/implemented product had good in-room sound reproduction behavior .