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Project 974   Legacy V Speakers & the Wavelet processor; SIX JL Audio f113's !

THE CUSTOMER PREMISE

Ongoing frustration with typical suggested setup procedures and equipment suggestions and limitations. In my 20-something years of tech support, I actually hear this a lot. "...I just spent x-bazillion dollars on my system and my dealer is a really nice guy and it still sounds like @#%$?&* crap! Now what do I do?"

So at the "now what do I do" phase is where I come in. The Soundoctor Makes House Calls™. You pay my transportation and lodging, and I put the adjustment fee on. If you are not satisfied there is no additional charge - but no one has ever been less than thrilled with the cost-effictive results. Stop wasting money on unnecessary tweaks! Please ask me first. My initial consultation is free.

Yours truly, SIX JL Audio F113's, and the Legacy Audio V Speakers

The SPEAKERS

The Legacy V speakers are very very odd, and very very interesting. In my opinion they are peculiar looking, hideous almost. But that can be overlooked if they sound fantastic. Not so fast, buddy. First, their premise: stick a bunch of low freq drivers all over the place - some inside the box and another in free space (the top driver) and expect good bass. It's AWFUL. Hence the customers' desire to buy the subs.

THE SUBWOOFERS...

OK, he really didn't NEED SIX JL Audio f113's! One or two would have been fine. If he wanted to imitate a pair of JL Audio Gothams he COULD have bought just 4 and stacked them. But he got a 'deal' on six, actually from another customer of mine who sold the f113's to get a pair of Gothams. (!) So why not! Do you really NEED 800+ horsepower in your car to drive to the supermarket?

THE WAVELET PROCESSOR (Preamp, DAC, 2 / 3 / 4 way digital crossover)

But back to the V's. They come with a fascinating 'controller' called a Wavelet Processor. There's a test mic that you connect up, the signal then goes via a web page, into the ether to their engineering department , where they then send you back the corrections for your system in your room.

ABOUT THE LIE OF "ROOM CORRECTION"

IF ONLY the hackneyed phrase "room correction" was anything but a lie. It's NOT CORRECTING your room; it's fucking with YOUR SPEAKERS. Real "room correction" is a truckload of burly dudes carrying ASC Tube Traps and other fine brands of acoustic materials into your room and placing them where they belong. YOU CANNOT CORRECT REVERBERATION WITH ELECTRONICS OR EQ. What you are doing is changing what's coming out of the speaker and then it bounces around the room. So you haven't fixed the bouncing; in fact often, you've made the direct signal from the speakers to your face - which is what you actually want - typically worse. This is not a Legacy nor a Wavelet problem; this is an industry wide LIE.

Even worse, with ONE microphone you CANNOT fix time related issues in your room at low frequencies. For example, that single microphone, with anyone's measurement system, CANNOT discern the distance from the Left sub to your face, the Left sub to the left wall to your face, the Left sub to the right wall to your face, the Right sub to your face, and so on — which is what the bass waves are actually doing. And most importantly, you CANNOT correct time (phase) issues with EQ!

You CAN, with EQ, pull down a peak at low frequencies at your listening position. Why would you have this? Reflected and standing bass waves will cancel at some locations (sometimes to essentially a complete null, (like 20, 30, or 40 dB down) and add at some locations, where they can only get 3, 4, 5 dB "more" — so you CAN easily EQ this peak out. But you can NEVER fill in a HOLE in the freq response; you are getting the hole because of mechanical wave cancellations in your room. You MUST fix the room - this is where correctly applied bass traps come in. Put another way, the MORE and BETTER bass traps you have the better the bass will be in the middle of the room.

Having explained all this negativity, the MANUAL EQ part of the Wavelet Processor is GORGEOUS. You are able with VERY SUBTLE EQ to make delicate yet compelling equalization changes which really do enable you to fine tune the tonality, if you will. They don't actually "tell" you the frequencies they are using (sure with a sine wave generator you could make your own chart or curve to See.) There is nothing wrong with CORRECTLY applied EQ, especially if delicately subtle. But be aware that early consumer "hi-fi equalizers", like those cheezy 5 and 10 band slider versions, are typically awful, since the bands are way too far apart, and the users typically have no frame of reference. They are toys, and intentionally avoided by "audiophiles".

If you want to correctly LEARN about EQ, either buy a professional 31 band graphic hardware box and plug it in correctly, (your tape loop or between your preamp and power amp) -or- you can download OCENAUDIO, (versions for PC, MAC, + Linux). It has a built-in 31 band graphic equalizer and what you would do is play your audio through it and you can hear what you are changing in real time, and you can store "house curves" and so on. This is far and away the best method for learning what adjustments are appropriate. But here's another caveat: you shouldn't do this until your system is set up as correctly as possible FIRST, using my Test CD, here: www.soundoctor.com/testcd . Yes it's a bit of a chicken-and-egg issue. I suggest setting up your system using my initial procedures and then, playing with EQ if you are new to this whole game, to learn how you can tighten things up. Everyone essentially NEEDS a correctly applied HOUSE CURVE.

But back to the Legacy issues. All those low freq drivers, and a passive radiator (even worse than a port because it has ADDITIONAL mechanical delay) makes the bass coming out of these things a complete mushy mess, with no timing, and no articulation. The entire concept, like any ported speaker concept in a living room, is flawed. Their TOP Low Freq. driver is OUTSIDE the box in free space. The other low freq drivers are INSIDE the box. Therefore the lower freq transients are completely turned into mush.

THE JL AUDIO CR1 CROSSOVER

What I elected to do was to (a) disconnect that top driver, and (b) consider the entire box an ENTITY, and cross the entire thing over at 90, using the CR1 crossover, which was my design concept at JL Audio. Therefore everything below 90 goes to the subs; everything above 90 goes into the Wavelet processor and on to the mains. Therefore there is NO messiness coming from the mains; the phase between the subs and the mains is tightly adjusted (more on this below) and the impulse response of the music is correctly played back. The result is clean and tight everything, with superb imaging.

THE PHASE ADJUSTMENT

In a situation like this one ideal is to place the subs where they belong, based on empirical tests, using my TEST CD. But when there is such an astonishing amount of headroom available, you can often (but not always) get away with simply putting the subs next to the mains and adjusting the phase. So what if there isn't quite 'enough'? You typically have a huge amount of headroom to play with.

So here is how the phase is accomplished. You start with CR1 set like this:

The JL Audio CR1 initial settings
The JL Audio Fathom control panel (right side shown)

Notice that on the CR1 both the SUB XO freq and the Satellites (Mains) XO freq are both set at 90. For the more advanced experiments, you have the option of over- or under-lapping the freq knobs, to assist in either response issues or for your preference(s).

Start with the LEFT channel only. Feed in a SINE WAVE AT the XO freq - in this case 90 Hz. Looking at the picture at the top of this page, you turn on the bottom sub only, You flip the wiring to the MAIN speaker so it is out of "phase" (POLARITY, ACTUALLY). You initially set the levels going to the main and the sub so they are essentially the same. You then place your body right in front between the main bottom driver and the sub bottom driver and turn the phase knob on the sub until it nulls out. You must try both the polarity switch settings on the sub (0 and 180) — whichever polarity position gives you the lower numerical setting on the phase degrees dial is what you use. With careful and subtle settings the 90 Hz tone will almost completely disappear. Be aware the null is about THE WIDTH OF THE POINTER ON THE KNOB!

Once the bottom sub phase is set, you can put the wiring back to normal on the Left main, then turn it off.

Now you have the bottom sub on, and the one above it. You flip the bottom polarity switch to the "other position", and null the middle sub's phase Knob. Then do it again: turn the bottom sub off, flip the middle sub to the "other" phase position, and null the top sub to the middle sub. Then, finally, put all 3 subs polarity switches wherever the first one wound up, and you're done. Now with all 3 subs playing you will get about 4-5 dB more bass than you think - which is where just about every system winds up with anyway as a preference. So-called flat response is not necessarily desirable, and a very gently sloping room curve is usually much better for PLAYBACK systems.

So using 1k as your reference, you typically want about 1 dB more per octave going down and 1dB less going up.

Therefore:

16 k   -4 dB
8 k    -3 dB
4 k    -2 dB
2 k    -1 dB
1K = reference level
500 Hz +1 dB
250 Hz +2 dB
125 Hz +3 dB
63  Hz +4 dB
30  Hz +5 dB

This is not quite as severe as it seems. Even a small "tilt" is desirable. If you feel so compelled to adjust everything "flatter", which I suggest not doing, here is how:

You start by putting the SUB/SAT BALANCE LEVEL KNOB 4 dB toward the left. This sends 4dB more to the sub so that once you null all of them, you then return the knob to 0 and now you have fixed the issue of the subs summing in the room 4-5dB louder. Now you wind up with just 1dB "more" bass. Pretty cool!

CR1 set at +4 dB for the SUB LEVEL

ALL IN ALL...

When everything was carefully adjusted with multiple iterations to "tighten it up" — all in all — the results were quite excellent. The customer did NOT have anything resembling correct acoustics in the room, and I suggested that be the next approach. With at least 2 corners (and preferably 4) with good bass traps, and some well placed diffusors, things would tighten up even more. The way the room is laid out there is no place really to place 1st reflection point absorbers, since the listening position is essentially mid-nearfield, at about 6 feet. That's darned close to six subwoofers! Even so, when playing well recorded demo criteria pieces, ( Boz Scaggs Thanks To You and Skylark, stunninngly clean and balanced mixes) and with careful and delicate tweaking (I think subtle 1/2 dB steps) of the MANUAL EQ settings of the Wavelet Processor, the results are quite wonderful.

A system like this is not for the casual listener. Setting it up (with or without subs) requires supreme dedication and often months of weekends of tweaking — part of what this audiophile hobby is all about.

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There is no plug-in for experience...
SOUNDOCTOR                  BARRY OBER           EMAIL: barry@soundoctor.com