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Affordable high end audio Those that are or have been bitten by the bug know what I'm talking about; the search for the perfect sound. It's almost inevitable when you love sitting back and just listen to music, you want to get as close to the real sound as possible, and that's where the controversies start. What is real sound? How much technology (money) has to be thrown at it to get it right? And what's right for one person may not be right for another. It's just like the clash between religion and science, any change in an audio chain can have a psychological effect, but measuring it shows no change at all. This has already been explained by Peter Aczel of the Audio Critic numerous times, and still no-one in the high end audio industry has proven him wrong while the opposite is done many times. And after reading plenty of information about it it has confirmed what I've noticed many times with a medium priced audio set, that it sounded very, very real. Having owned and/or listened to plenty of equipment ranging from the 4 digit to 7 digit prices made me doubt if there was really something to my gut feeling. But it was true, get some decent equipment -which to me would be components that don't feel like cheap plastic boxes-, get some cables for a few bucks to replace the flimsy threads usually included with everything, and spend the real money on good speakers. That will give you the most bang for the buck (literally with large speakers :-) ) with the commercial products. If you want to take it a step further, go diy. There are great things to be had for those that can (or know someone that can) build the components themselves. It was thanks to all the info on the internet that it led me to several informative sites, among which the Audio Critic and Linkwitz' speaker designs. From there I learned more about going active on the speakers to get better performance out of them. Looking at options to convert my current Tannoy Sixes 611 (yes, definitely not considered high end, but still good speakers) I came across several pointers to the Behringer Ultradrive Pro DCX2496. It's a digital crossover with plenty of features besides just playing filter between speaker units. And it's very cheap compared to the units made by high end manufactories. As I planned on getting an Orion++ or something similar I figured I'd see what difference converting my current speakers to active ones made. The nice thing about the Tannoys (and similar designs) is the stable soundstaging as most of the sound comes from a point source. I bought another Rotel power amp and grabbed the Yamaha integrated from the bedroom and hooked them up after the DCX. What I had now was a VIA Eden pc with Terratec soundcard connected to the DCX as the media server/player and three amps connected directly to the speaker units without the passive crossover connected. The crossovers were set to below the standard frequencies as I set the filter slopes to 48 dB, taking more mids away from the woofer and moving more higher frequencies from the mid to the high unit for better dispersal. Immediately I noticed music sounded more clear, bass tighter, overall a definitive improvement. Also, thanks to the quality of the Tannoys, I could go very, very loud with music when the neighbours were away before my ears gave in. I've been enjoying the music once more with this setup, and the next step came some time later in the form of a Behringer Ultragraph Pro DEQ2496 ; it's a digital equalizer stuffed with features and includes a real time analyzer. This type of unit is probably the biggest no-no for audio purists. And it's understandible. But seeing as two speakers in a room will never give a flat response at the listening position without extreme measures it can get you much closer to the intended sound stored on the CD/LP/etc. At first I used it to modify the soundstage to enhance recordings of live concerts (outdoors and indoors) and get more punch when watching movies. As I had bought a measuring microphone as well I sat myself in front of the set one afternoon and went through the options of both units to improve the sound even more. First I used the automatic delay and polarity option on the DCX; this gave more depth to the soundstage. Next I used the RTA option on the DEQ to get a flat response in my listening position; this also improved the depth of the soundstage and pulled the music further away from the speakers. I began noticing more new things to different musical pieces and I also noticed that it felt like I played music louder, yet the output indicator leds on the DCX didn't flash even once as they did once in a while. Another post on the net about the DEQ pointed me to the option of doing the RTA per channel instead of both at once, something I had overlooked in the setup. Doing the RTA once again per channel improved everything once more; the effects on Roger Waters' Amused to death came from beyond the speakers where they're supposed to be. I've even heard these effects on recordings that were not made with Q sound. Shifts between left and right when an instrument played from low to high frequencies were gone. That which can be reached in a tuned room with high end equipment was now achieved in a (reasonably) ordinary living room with a much lower pricetag. The improvements with the DCX, DEQ and extra power amplifiers are to me worth the extra money as trying to comes close with the regular commercial products would cost a lot more. The next and maybe final step will be building open baffle speakers inspired by the Orion+, except these will have 4 woofers, 2 mid and the 2 back-to-back tweeters in a WW-M-T-M-WW configuration per channel, perhaps also build with only high end Visaton drivers in a complete single manufactor (test) concept. Of course, if the room itself is totally unsuited for listening to music, this setup will not make it that much better. Start off with some acoustic room treatments first. Later notes: I just can't leave gathering information alone, I keep going back to Google searching for speaker types and constructions, especially open baffle and I find lots of forum posts about less known items. One of these is the Karlson speaker; the exponential opening I've seen before in a speaker diy book but these are the originals. The exponential shape might be something to incorporate in the baffle shape of a dipole. Another is about ambiophonics; reading more about this makes me wonder if it's the processing of the music, or the directivity of speakers that makes people prefer ambiophonics or regular stereo. It seems to me the thing that gives the listener a wider soundstage is that he's hearing more reflections compared to direct sound. I've noticed it with some tracks when I had my laptop in front of my face and I noticed an instument coming more from the side. The whole setup -which seems like too much of a hassle than it's worth to me- is mostly about controlling the reverberation and reflections as far as I can see, and the main thing that disappoints me is that you're still restricted to the sweet spot. Reading about a review of some 3 channel sacd recordings from Linkwitz confirmed my idea that the drawbacks of regular stereo they pointed out are more the fault of recording with two microphones close together instead of a couple of metres apart and using speakers that are too directionally constrained. Even with my current Tannoys I have a stable, defined centre and what lacks in wide horizontal imaging is better sidewall reflections because the higher frequencies drop off quickly to the sides of the speakers. This would also explain why adding the centre speaker to the Orions only gave an improvement on a original old 3 track recording of RCA reviewed by Siegfried. The others didn't benefit from an added centre channel compared to the image presented by Orions. If ambiophonics would present a good soundstage no matter where one sits in the room, then it would be worth pursuing. As it is now I see no more benefit than to using good (open baffle) speakers with wide dipersal because when one wants to really listen to music, one always sits down at the sweet spot anyway. Home theatre systems are very popular but as I found out a long time ago, sitting down in front of a good stereo gives you just as much surround effects with a good soundtrack. The only thing I do is increase the bass with the parametric equalizer to get the bass rumble and punch that seems to be the thing for HT systems. Having listened to this setup now for some time, I still have that great feeling when listening to favorite music. To me it's like getting into my Alfa Romeo 164 Q4 and driving off, I still get a thrill even after all this time I own it. Mentioning the PRaT factor has gotten a bad name with serious audiophiles, but it's like I found the ultimate PRaT setup, knowing full well that my current speakers are not the best I can get. And what I noticed when doing some critical listening -for as long as I can because I get drawn into to music instead of analysing it- is that records aren't all balanced perfectly indeed. Some divert one or two tenths of a dB to left or right. But I don't have to change the output levels on the DCX as moving a tiny bit left or right will do. Even artists I'm not a big fan of seem better. I've joined three songs from Marillion into one (q10) ogg vorbis file called "Kayleigh in lavender kimono" (guess which three songs) and I truely get a kick of the music. This is what a setup customized to the room does, music becomes magic. No wonder speakers like the Emerald Physics CS2 have become so popular. My conclusion of these experiments are; to get that jump into excellent musical performance buy the DCX with measuring microphone, DEQ, the extra power amplifiers -and a pre amp if you dont have one-, grab the screwdriver and wire cutters, rip out that passive crossover and go for active, room compensated musical bliss with your current speakers. An upgrade of speakers can always be done later. (just don't forget the cables as I did once. :-P ) Making it even better would involve running a spectrum analyzer and levelling out the pink noise by the parametric equalizer on the DEQ instead of the automated RTA. I'm looking into getting that done with a laptop and baudline. Hell, I'll get my toolbox, rip out the crossover and do the setup for you if you don't dare to touch your speakers. If you live in the Netherlands though. :-) Remembering something I heard about years ago, getting stereo from a single speaker, I stumbled across Airsound when searching the net. This once again confirmed my idea it's important to get side reflections from a stereo setup. Because there was already something in my mind to experiment with I took my speakers and moved them around while listening to different music. I had them closer together just to the sides of my tv, no toe-in, and that resulted in a great stereo image with good recordings, yet the width of the sound stage was too small for regular recordings. Using the stereo widening capabilities of the DEQ or the extra stereo plugin for Audacious didn't help much, the sound information just wasn't available in these recordings. Moving the speakers back to a comfortable stage width, but keeping them straight was what still gave the great stereo imaging. Because there was no toe-in I get more sidewall reflections, hence the effect and the need for more omnidirectional speakers. Thinking more on this and the previous techniques I wonder if the best setup would be to have a center speaker (or two directly next to the tv) fed by the mono signal from a Behringer DSP2024P, and two speakers to the front side fed with the pure stereo signal of a second unit. All speakers would have to be identical dipole/omnidirectional and calibrated to blend in as much as possible. This would be the most logical setup as there is the mono sound in the center and the stereo filling the rest. This is true especially for studio recordings. And for the surround lovers there's always the addition of two more DSP 2024Ps with stereo speakers to add the side and rear reflections in the room. This setup would give a lot of control on the strength of the front and side signals, but, as said before, when sitting down to listen to music it is done alone, and there's no need for a wide sweet spot so it's more for watching movies with an audience. Also, creating a setup with 2 or 3 DSP 2024Ps to create a surround setup would require changing the effect with every genre of music, so it would be a bother after a while. Having tried the binauralizer effect, it didn't improve the stereo imaging as it theoretically could, on the current traditional stereo setup though. Judging from the possible settings it's intended for large stages, not home use. Stereo widening also didn't improve things, but using the stereo imaging effect did. Keeping spread at 100, turning the M/S balance to 43 to increase the mono part gave me a more balanced soundstage on the choir part of the original HDCD sampler. Instead of clinging too much to left and right, it was now spread evenly from left to right. So far I haven't heard any worse effect on regular types of recordings other than a smaller soundstage. But also here there were no apparent gaps between center and right or left anymore. Some recordings though have a lot more stereo and room information, so these sounded better without the enhanced mono effect. One example is the best of Bon Jovi. I really like a few of their songs, but the recording is really flat. Hardly any room information in the music. Using the DSP with room or hall effect gives it more space, but it's more to the back. Good recordings also bring the music more in front of the speakers. Good recordings immerse you more into the soundfield and it's shaped like an ellipsoid looking from above. Even later notes: Reading up on reviews, technical papers and experiences with dipole, bipole and omni-directional speakers I concluded that dipole would be best. Omni sounds like a great idea but I see trouble in the various designs encountered so far. Most are of the T-M-W version, so the lower the frequency, the lower the sound source goes, something I've noticed with speakers and why I prefer coaxial/coincidental and M-T-M designs. (might be no issue if the distance to the speakers is large enough, but I don't have such a large living room) Of course, omni can be of the M-TT-M design, but then the distance between the midranges could be much larger compared to M-T-M on a baffle. (and I do mean TT as a single tweeter in omni would be uneven in the vertical axis) Somehow getting the midranges closer together would most likely decrease the vertical dispersion, with the drawback of a less high soundstage as Peter has noted while reviewing the Beolab 5. The omni designs also still have all the disadvantages of the box design; colorations caused by the box, reflections coming back through the diaphragm, compression, etc.. Of course, the woofer could be set up as dipole, but then you get two different polar responses mixed, and the midrange is still boxed. More info regarding surround, especially this post on the Hydrogenaudio forum made me think on what extra the 6 channel sound provides, especially the way David Chesky implements. Right now I hear reverb all the way to the sides with stereo recordings that contain this info. Also, soundstage width is as wide as the recording provides, which might just get a little wider when the current closed box speakers are replaced by dipoles. Only the back reverb is missing but I do sit with my back against the wall so I'm not expecting to hear anything from there. I think the effect the surround channels provide can be synthesized by using DSP processors. What else than the sound of reflections are coming out of the extra 4 speakers? Okay, it might not be exactly the Concertgebouw in Amsterdam, or Jazz at Pearl's unless you have the exact specifications, but the advantage is being able to create a soundfield to one's own taste. Question is also how long until the novelty wears off and listening to "plain" stereo is preferred. My guess is with the right dipole speakers having a surround setup isn't interesting anymore. How important room acoustics are was made clear once more after I replaced the wardrobe against the right side wall with the same shelves and couch as I use at the left wall. The setup is shelves in the corners and the couch between them so there's a large open space where the sound is reflected back to me by the concrete wall. Reflections are now just about the same from right and left and it has opened the soundstage even more to the sides and back. The loudspeakers often disappear with good recordings and I've been enjoying music even more, even if it's not exactly my taste or the (good) recording has been ripped to 112 or 128 Kb MP3. Also, with some recordings I've heard some instruments like I'd hear them through headphones. A good example is the Nightfly from Donald Fagen, the synthesizer sound on tracks I.G.Y. and Ruby baby surrounded me instead of coming to me from the front. I think it's especially obvious with piano which seems to be recorded with the mikes at close range. It's like I sit right on top of or with my nose against the piano. This sort of envelopment I've never experienced with (very) expensive high end installations. And of course the Q sound effects on Roger Water's Amused to death were even more pronounced. Movies had to be checked of course, and again, surround sound coming from just two speakers is definitely possible (a good excuse to watch Lord of the rings again). I don't think adding two extra front effect speakers as in the Chesky setup will add to the soundstage width as it has already been expanded as much as the acoustical information in recordings allow. There seems to be one more effect, more volume at the same level. Unless the recabling everything to replace the old tv stand with a new low rack for tv and stereo equipment removed a restriction, the stereo plays louder since replacing the furniture. This proves it's important to try to keep the interior near the speakers as symmetrical as possible, as Siegfried Linkwitz talked about in his presentation on room optimized stereophonic reproduction, and not try to absorb reflections. And some weeks later... Direct/reflecting sound is essential, but somehow seems to be ignored by the majority of loudspeaker manufacturers. I've read loads of speaker reviews but to me it seems there are only a few reviews that talk about a convincing musical experience, and those speakers are always of the (part) dipole or omnidirectional variety. Using speakers that only produce direct sound don't reproduce the environment of the recording. It's more like listening in dead space. That's one thing Bose was right about, reflections are important to recreate the correct musical environment. But too much takes you further away from the musicians. A good example was the experience of 6moons reviewers with the Podium Sound speakers. In the publisher's comments he described the layered sound experience, direct sound from (conventional) speakers and the ambience from the decorrelated sound of the Podium speakers. And there was never any question of room acoustics getting in the way of the recordings. As long as the radiated sound from the speakers is consistent in all (horizontal) directions, the room acoustic signature is ignored by the brain. This I noticed with some recordings, there is a difference between getting the musicians in the room and being there at the venue. Ever since the stereo setup takes advantage of side wall reflections I felt I was there rather than they were here several times. Having seen photos of some of the reviewers' listening rooms I wonder how on earth they could get any potential out of speakers, let alone review them. Current setup; VIA Eden pc with Terratec Aureon Sky 5.1 soundcard, FreeBSD 7.x and XMMS for media server. Analog signal fed to the DSP 2024P for mono/stereo balancing or DSP when preferred, otherwise directly to the DEQ 2496 for room compensation, the DCX 2496 for active amplification to 3 Rotel power amplifiers driving Tannoy Sixes 611s. Crossover points are Linkwitz-Riley 4th order 1710 and 69 Hz (original is lower order 2500 and 400 Hz). I used to cross mid and low at 111 Hz first, but as I often felt that the soundstage was lower than tweeter height I guessed the woofer might pull the stage down. And it did as letting the woofer handle only sub low restored the stage height. As an extra I enabled high and/or low pass filtering on each output to drop the frequencies around the crossover points with another 15 dB to further reduce interference between drivers. Delay of the low and mid output is 44 mm/0.13 ms and polarity of high is set to inverted. Due to the low crossover frequency for the woofer I can keep the amplifier for the woofers turned off quite often. I've noticed that the jazz selection I listen most often to still sounds great without sub-low. Ofcourse it's also due to those frequencies not being used much by the instruments, so I can do (semi-)casual listening this way and turn on the woofer amp for the music and the movies that go low. No pre-amp is used, volume control is done at the source and it has no effect on the quality of sound as many fear (listened extensively to various recordngs). There will be a pre-amp coming as I want to hook up my Yamaha GT-CD1 cd player again (according to the linked forum it could be one of 2 players originally imported for Europe, maybe even the first), as well as my Pioneer laserdisc player. Btw, cables? Standard interconnects from the pro audio shop and thick enough cheap wire for speaker cabling. All that matters is low resistance, the rest is moot. 2009/12/31, for the first time since I started using the DCX I've played some music at volume level "live". I give myself a few hours on the last day of the year to go all out, and my ears start distorting before the speaker does, with 15-20% volume headroom to spare. These Tannoys can go really, really loud in an active setup. Next thing to try; Get a second DSP and drag the bedroom stereo into the livingroom to turn those into front side speakers. Then I can try the mono/stereo ambiance setup and see if that's a step in the right direction. Or, build the open baffle 3 way design I have in mind with Visaton G 20 SC, the TI 100 and the TIW200 XS in a WW-M-T-M-WW tower with a second tweeter at the back; The tweeter and mid show a very wide dispersion profile so with a crossover at 2KHz - 2.5KHz the power response for a 180 degrees angle should be perfect up to close to 3KHz, then fall off to -8 dB at 8KHz and faster above that. Anything about the figure 8 dipole response that lessens the response angle width will only add to the liniarity of the off-axis response as I see it (and then I could raise the high crossover as well to relieve the tweeter). Using 4 20 cm (8") woofers instead of 2 25 cm (10") as in the Orion design keeps the baffle a little smaller and increases the volume displacement a bit. Also, I believe this will accelerate the air at low frequencies more evenly across the height of the room which might reduce some distortion or room modes. One drawback I can see so far might be a limit on how undistorted loud this design can go with the 2 cm tweeter and the 10 cm mid/woofer, although I think that limit is high enough to hardly ever get there. One way to alleviate the burden on the tweeter would be to add a second one in front and back to half the power up to about 3KHz, sort of what Dynaudio does with their Evidence series. Another drawback would be the usual limit on how low the speaker can go, but that can be fixed by adding (at least) two subwoofers from 50Hz downwards. At these low frequencies dipole should have no advantage and the woofer can be placed in a closed box. Add to this one extra DCX 2496 as I'll need one per channel now in a 4 way crossover configuration. (I prefer this over adding a seperate cheaper crossover because of the timing/phase options in the DCX) Another option, I might run it as a 3.5 way, having the inner woofers run from maybe between 200 and 500Hz downwards to relieve the midranges, and the outer woofers from somewhere between 70 and 120Hz downward. Only then I'd need a fifth stereo power amp if I want to use the extra seperate subwoofers. Class D multi-channel amplifiers will sound like a good idea then, although I like the look of one silver RB 1070 on top of a RB 1050 which sits on top of a black plateau next to each speaker. Resulting equipment configuration would be digital output from soundcard to the DEQ, then to pre amp, split left and right to one DCX each which divides it 4 way with high and midrange to one, the mid-low and low to the other power amp. Using two DCX's regardless of configuration would give the possibility of delaying the back tweeter to match the midranges, although what that will do with the polar response is unknown. After that last design idea; reading about a lot more diy open baffle designs and using several spreadsheets to get an idea if it would work, my latest idea is not to use the TIW200 XS but the cheaper W 200 S down to 69Hz and fill in below that with two open baffle H-frame towers (190 x 35 x 35 cm) with 6 x W 300 (30 cm/12") each. A quick displacement calculation showed 103dB at 25Hz for one tower, but that's without all other factors included. More than enough for my home theatre use as I turn down the volume quite quickly at the loud passages because often I don't like those. Using 40 cm (15") is not a good option as I'd only be able to use 4 per tower (ceiling height restrictions) and the width would be too large for my taste at 44-46 cm. This would in the case of the BGS 40 decrease the maximum volume displacement and reduce the 103 dB at 25Hz to 101 dB as well. Amplification will be something from pro audio equipment as you get plenty of power for low cost (and no, I haven't heard any sonic improvements with expensive amplifiers, don't go into distortion and the output is identical). Power would be needed with 3 W 300 8 Ohm in parallel giving 2.66 Ohm resistance so I'm thinking 1 Behringer EP2000 in parallel mode per tower as it rated at least 650 W at 2 Ohm per channel (the pro audio shop is very close and the Behringers were the only one giving power data at 2 Ohm). Design plan: Main tower: 190 x 28 x 28 cm flat baffle/H-frame, 3.5 way with 2K, (250 + 111) Hz crossover points in W-WM(T/T)MW-W configuration. Bass tower: 190 x 35 x 35 cm H-frame, crossover point 69 Hz. (all crossover points can change depending on the listening tests, using the DCX's is just great for this) At first I thought about painting the towers black with a small band of wood grain at the front sides to make them look slimmer, but later I got thinking about high gloss white. Four big white columns of sound would make the room feel less dark than four black ones. Looks like the design isn't common as I've not seen anything like it except for the Audio Artistry Beethoven Grand, one four tower version but using ribbons for mid/high and on diy sites I've only seen one pair of WWMTMWW towers. (and no, the design is not meant as a copy of the Beethoven, but grew out of expanding the Orion/Orion clones, just the other direction of the Orion's development (reading through the specs I see I thought of some of the same crossover points). Then again, four towers don't have a large WAF factor and in smaller rooms it needs to be set up along the long wall. I am thinking of building a version without seperate bass columns, but first I just want to go all out. I can try to get close to the best later. For now this design is just for the music lover who wants the best (in my own humble opinion of course). *I forgot about Siegfried mentioning Brian Elliott on his site. The first instance he heard real bass with two dipole woofer arrays with also 6 30 cm woofers per side, so I'm pretty confident mine will play just as well. 2010/01/13, the project has started with the arrival of the drivers. Now I'm looking into either doing the woodwork myself or outsourcing it as that would make it easier to saw the large sides and driver panel for the woofers. I don't have the tools for those parts. As an experiment I hooked up 4 30 cm woofers to the Tannoys in place of its own woofer. The woofers are placed on the ground with a small box under the magnet to keep it upright. Dipole bass sounds cleaner, "drier", indeed. Low frequencies are more like seperate waves instead of one bunch of rumble, even though the bass of the Tannoy was already very good. Another change was a slight sense of more depth, most likely from more sense of reverberation in the recording. Exchanging the tweeter by placing the two G 20's on top of the box, one front, one back in opposite polarity, added more depth to recordings and made the speakers disappear even quicker depending on the recording quality. The most obvious was heard in the depth test on Chesky's Jazz sampler and test cd, it sounded like each distance increase was twice as much as before (9 feet sounded more like 9 meters). For me it proves that a dipole speaker should have a dipole polar radiation across the full frequency range, not just only in high and mid, or only in mid and low. Even in this experiment with mid in a closed box and only high and low in dipole an increase in depth is heard. 2010/01/24, went through the whole DCX and DEQ setup as it'll take about two weeks before I get the MDF panels, glue them together, attach the units etc., and in the meantime I want to keep enjoying this part dipole sound. This improved sound once more, especially the lower octaves making obvious why dipole bass is better. I could rig something together temporarily to go full dipole, but then I might as well do everything myself, and that would cost twice as much as outsourcing it now. If I'm going to start building the other designs I have in mind I'll get all the tools needed. 2010/01/26, bought the two Behringer EP2000's today, hooking one up insted of the Rotel 1070 for the woofers to see how it runs. the second DCX will have to wait until it's in the shop (not in stock). Too bad because I wanted to start rewiring everything in preparation for the new speakers. 2010/01/28, having (not even serious mostly) listened to this setup for a little while now I noticed how often it's like the sound originates in this room. Yes, the speakers are in the room but voices, instruments, etc. have this sense of being really here. It's like I can reach out and touch everything. On recordings voices can really sound like they've been recorded and played back on a (good) speaker or PA system, it's just that that speaker is right there in front of me. I can virtually see it, touch it. Now I'm getting even more curious about how the new speakers will perform, and how they'd compare to Emerald Physics CS1.3 or CS2.3 and B&O's Beolab 5. And also how Tchaikovsky's 1812 overture canons will be handled by the subwoofers. So far the 6 naked woofers have managed to drive the EP2000 in clipping, but that was with a boost of 12 dB at 20 Hz from the DEQ on top of the 15 dB lowpass boost in the DCX. The H frame and doubling the woofers will certainly help in reducing the boost needed at those low frequencies. 2010/02/01, one more design I have in mind would cost more on drivers than the current project, close to 2500 in total. But then it's also a partly unique hexagon shape, alternating 15 and 6 cm sides, on each wide side 8 13 cm woofers, 2 10 cm midranges and 1 tweeter in WMTMW configuration for a total of 48 woofers, 12 midranges and 6 tweeters for both channels. The advantage with this closed box (semi-)omnipolar design is that it would only need 6 channels of amplification as it's 3 way active. One side of each speaker would also get a switch to reverse polarity to give it some cardoid polar response, giving more choice in room placement or listening preference. 2010/02/13, the two open baffle subwoofer towers are assembled and playing alongside the Tannoys for today. I've reduced the output by 24 dB compared to the midrange, and still there's a little too much low end. Raised the crossover frequency to 499 Hz so the balance is better. While playing different styles of music it's obvious how easy it's reproduced by a large surface area of 12 30 cm woofers. Expressions like clean and relaxed but fast (not dull) are in order just as used with for instance large panel ESLs. Good examples are the guitar at the start of Rotten Apple by Alice in Chains and the bass drum on the Countdown to Extinction album from Megadeth. 2010/02/15, finally done. The build has left me quite tired after working 3 days but they're playing, and play they do, even if the source is my Cowon portable as there's a problem with the new audio subsystem in FreeBSD 8. Until the compile back to 7 is ready I'm getting a feel for the system by using the Cowon. One (obvious) thing I noticed is that music is coming from between the speakers and then further back, not from the front as with the Tannoys. Playing some Jimi Hendrix made me notice how easy not just bass drum, but also guitar is reproduced by an open baffle speaker. 2010/02/18, after listening to the new speakers for a few days and getting used to the new sound I have one word to describe it; unspectacular. Music is just there. Not exaggerated, not muffled, nothing is added or taken away. I notice more detail in recordings but it's like I just get more information without any hype. My foot still can't keep still while music's playing so everything's still, well, musical. Never heard heavy metal so undistorted before, and some songs with so much artifacts that at first I thought a speaker was defective or the noise cames from outside the room. Because the DCX is a pro audio device I hear more hiss coming from the higher efficiency mids now. The 1070 Rotels don't have a way to adjust gain (at least not from the outside like the 1050 does) so they amplify the noise floor much more than the EP2000's. As the 1050 is no longer available in stores anymore I'm thinking of getting two more EP2000's for the low and mid/low stages. Might as well test their sonic performance on mid and high when I turn down the gain on these, as distortion might increase this way. Will have to replace the stock fan with a lower noise version though. For now I've just unplugged the stock fan and the amp only gets a little warm with normal listening levels, I'd say just as much as the Rotels. But when summer comes and temperatures inside rise with at least 10 degrees C more and I play at higher levels they will get warmer driving the 12 woofers, so it's better to add that bit of extra cooling. I doubt the amp will get really hot though as I'll not be cranking levels for hours and they are already pushing a load of 2,66 ohms right now. 2010/02/20, testing the EP2000 for mid and high was positive, so today was the last addition with two EP4000's. There was only 1 EP2000 in the Feedback store so I decided on the EP4000. The price wasn' t that much higher, I didn't feel like waiting until next week to get them and as I've seen the EP2000 go into clipping with Overture 1812 I already pondered on getting the EP4000 for the subwoofer towers. I just have to wait now for the silent fans to arrive, then I can replace the stock fans and rearrange the tv/stereo rack (again!). At least then I'm finished with it apart from a possible preamplifier and the cosmetic touch to the speaker columns. 2010/02/22, unexpectedly my sister has an ear for good speakers. She mentioned she had been to a small speakerbuilder because her friend was checking out speakers and she could hear the differences between the models on demo very well. She also mentioned the bigger and slimmer the speakers are, the more she likes them. I think plenty of men would like to have that WAF. So, when she mentioned how wide, deep and layered the soundstage was on these speakers I knew my design succeeded. And 1812 can really be controlled by these. notes Most sensitive frequency band at lowest level: 1500-6000 Hz At 60-70 dB: 200-7000 Hz About 11% of the sound in a concert hall is direct, the rest reflections (but I expect it to depend on the seating as well) according to Bose, another manufactor claims the ratio is 30 to 70. The majority is reflected for sure. The path to audio nirvana starts with letting go of common audiophile misconceptions, and -especially- feeling healthy and happy. (visit Jamendo for some excellent music downloads, they offer ogg vorbis as well and I did nothing but enjoy the good recordings I got from the site, some are just audiophile quality and addictive on my stereo setup, especially from the jazz section)
	The reason why is just as important as the answer to the question	mail? nystrom.nl, marcel