active speakers, Paradise? Trouble in paradise?

Hello all, a bit off subject, but in line with the conversation. I have recently switched to computer audio. I'm using foobar. I have noticed that there are basic eq settings within foobar that would send the info to your dac, so the music would be eq's completely within the digital domain. This would make your dac output the signal already eq'd without adding the issues that normal analog eq's cause. I haven't yet, but I will play with this some over the next week or so, if there is any interest, I'll post my findings. Could be a reasonable solution to Shadorne's correct post.

Digital EQ is wonderful and there is a huge amount of hype and marketing for auto-EQ equipment (hook up a microphone and press a button and presto your sound is "optimized") but it is important to recognize the limitations. First and foremost it is always better to improve room acoustics, speaker and listening positions. After as much acceptable acoustic improvements have been made then it falls to EQ (with digital EQ being the most flexible). Below 100 Hz the wavelengths are 10 feet or longer. These frequencies are a reasonable target for notch filtering as you can remove nasty room modal resonant peaks and have an effect on nearly the entire room because the wavelengths are long enough.

Above 100 Hz my recommendation is not to use any sharp EQ. I am fully on board with any broad treble of bass tilt adjustments to suit your tastes and room general issues but nothing else (for example a room with a tile floor will probably be too bright unless you turn down the treble a wee bit)! The issue is that at 1000 Hz you have wavelengths of the order of 1 foot - this means that you have a peak and a trough of a sound wave over a distance of a mere 6 inches. This makes it impractical to have any meaningful effect on the room at all (the benefit may be fine for one microphone position but detrimental for another). All you can do is correct a little for problems with the recording itself or the equipment itself (and, as with the room, it is first and foremost better to get equipment that works for you without needing tweaks)

In any case room EQ is an important topic but a separate issue from active vs passive speakers as it can be applied to both.

As Doug and several others have mentioned - ridding yourself of the passive X-over and the limitations of passive filtering of high power signals is perhaps the biggest advantage of "active". For the same reasons that single driver speakers sound so lively and clear (but have limited frequency response), active speakers (or at least well designed ones) all share a lively dynamic sound as if a veil has been removed. I believe this is because of the removal of the crossover. Passive crossovers rob some life from the music over quite a wide region - up to a couple of octaves. These passive crossover issues have manifested themselves in the need for massive monoblock amplifiers to breathe life back into the music. (If we look at Active speakers then we find the amplifiers are rather modest in size for the equivalent power output)

Some or much of my own confusion rests in the terminology being used I suspect.

I’m understanding so far, an active speaker may or may not have it’s own power cell to fuel the speakers with, and that active units pre-determine the optimum range for it’s drivers by filtering what portion of the bandwidth gets amplified by which amp for what driver!?

Fine. No prob there.

Apparently these ‘filters’ (adjustable or fixed, and at whatever total amounts of available power/watts) are actually not affecting the signal integrity, but allowing only bits of it to be applied to which ever transducer (s), so these filters are brick wall openings for certain frequencies.

Holes in the dam, huh?

What then, creates such an inoccuous non interfering slicing and dicing of the signal so the intended amp see’s only it’s portion.

What is the electronic dam with holes in it?

Or, in other words, who or what is the traffic cop doing all the directing of the audio signal, to these anxiously awaiting amps and drivers?

I’m having a hard time discerning any diffs from filters used in active x overs, and passive x overs… apart from this one thing.

All the freqs of the signal pass into the passive x over… getting shunted out here and there as they arrive, perhaps with some bleeding over too in areas they were not intended to land.

OK.. but something must stand in the way of the signal at some point to direct which part of it goes where and IMHO.. that sure seems a x over to me, more than a filter….

UNLESS… each amp is built with limits of bandwidth operation… that would do it too, I suppose.

Still the signal can and will be affected by the impedance of the incoming device feeding it/them… all of which changes with frequency and the number of amps the source or preamp has to feed/see.

Or am I way off with this assessment?

The big positive as in the Legacy model was the flexibility in the software which has some end user adjustment/flexibility.

Shaterne
Is the dollar to performance steps in active x over and/or self powered speakers about that of passive ones?

Does your 6K active speaker buying buck get you more speaker than it would in passives?

Thanks…

Virtually every multi driver loudspeaker system has to "slice and dice" the signal with a x-over of some sort. In the broadest sense, if the x-over is ahead of the power amps in the signal path, the speaker can be called "active", because the x-over unit is an active component. Even if the active crossover, power amps and "drivers in cabinet" are each from a separate manufacturer, this is still an active loudspeaker set-up.

A single driver type monitor coupled to a powered subwoofer are, in this sense, an "active loudspeaker".

I think some people prefer to restrict the use of the phrase "active loudspeaker" to an integrated, active loudspeaker system in which all three functions (active x-over, amp, and speaker) are sold as a system.

Personally, I use the broader definition.

Marty

BTW, if you use exclusively digital sources (or don't mind A-D-A conversion of your analog sources), you could look at digitally room corrected active systems. In addition to the sophisticated room correcting EQ function, these designs go a step further in refining the "slicing and dicing" function of the x-over. Both Merdian and DEQX powered active speakers (like those from Salk, if they still make 'em), for example, employ active x-overs operating in the digital domain. This set-up offers certain extra benefits (in theory, at least) over even analog active systems.