This is always a problem with horn loaded speaker designs. Bass horns are too big to get the bottom end people want, so they go with direct radiators. They never quite match. That's the answer. If you can live with it, fine. If you can't, then you must look elsewhere. I use high efficiency speakers, but I draw the line at front loaded horns. There are very detailed, efficient speakers out there that are not front horns, but are rear-horn loaded to increase bass efficiency. Many are single-driver types such as the Carfrae, Lammhorn, Beauhorn, Lowther, Loth-X, etc. Most use the very good Lowther drivers. They are considered to be among the finest speakers in the world by some. If you like the efficiency and detail and lifelike presentation of horns, but would like better integration and less coloration, then the speakers I mention above would be a good place to start.
I just got a set of Duos with the Audiopax amps, and they have proved to be very challenging indeed. I can see why a lot of guys hate them, if not perfectly set up and placed with the sub controls set just right they fail to make audio dreams come true. I have not realised the potential of mine yet, but am getting closer everyday.
Not to mention the fact that the Duos take about a month of constant playing to really break in. They sound awful for the first week.
I agree that the bulk of the difficulty arises in the bass. Every little move I make to the Duos seems to have much bigger impact than what I have been acustomed to with box speakers. Plus the controls on the subs are extremely powerful with numerous possibilities for optimal settings. The toe in amount is also hugely important to get right.
If I had not been pre warned that the Duos can be very tweaky and difficult to get the most out of, I might have been ready to throw in the towel. This is not a set it and forget it speaker if you want to realise it fullest potential.
Sorry to say, you heard them the way most of us have. They are very impressive, but problematic. It is the downfall of the speaker. Maybe the Trio is better because of the added woofer horn, but the Duos do not seem to go down enough with the mid horn and clearly shows the problem.
The Avantgarde Duo's are a very well thought-out design, but like all speakers embody compromises.
You see, it's not possible to build a reasonably compact woofer that goes deep, has high efficiency, and matches the radiation pattern of the horns. Not even close!
Avantgarde has opted for a fairly compact woofer that goes deep, which is probably the best decision, and provided a separate power amp and plenty of flexibility in the controls for dialing in the best possible overall sound.
Let me describe the two areas where the woofer system has compromises (this is not a criticism, just a description - compromises are inevitable in speaker design).
First off, there is a significant discrepancy between the radiation pattern of the woofer and of the horns. The horns produce an approximately 60-degree radiation pattern, and the woofers are approximately omnidirectional. Let's look at the implications of this - if the woofer level is set so that its first-arrival sound is at the same level as the horn's first-arrival sound, then the reverbrant sound in the bass region (resulting from that omnidirectional bass pattern) will be about 9 dB louder than the reverbertant sound in the mid & treble region. So, the bass will be overpowering.
Conversely, if we set the level of the woofer so that the net in-room volume level of the woofer and horns are the same, the first-arrival sound of the woofer will be about 9 dB down, with a resulting loss of impact (these numbers are estimations, but the trend they illustrate is valid).
So the woofer level setting is an inevitable compromise between a thick bass on the one hand, and weak bass impact on the other.
By the way, a bass horn would be the obvious solution because it could match the directional characteristics of the mid & treble horn, but bass horns are about the size of refrigerators.
Looking more closely at the wooferbox itself, there is an inevitable tradeoff relationship between box size, efficiency, and bass extension. Avantgarde has gone with a reasonably compact box size and deep bass, which means the efficiency is fairly low. Now, there is a correlation between efficiency and dynamic contrast, so we would expect the woofer section not to have the wonderful liveliness and dynamic contrast of the horns. While I'd have to say the woofer does better than expected in this area, there still is an audible dynamic discontinuity - the bass just isn't as lively as those horns.
Now, we all have differing degrees of sensitivity to different colorations and imperfections, so until they build the perfect loudspeaker, we're left to pick the set of imperfections we find least objectionable. If you are epecially sensitive to the lack of coherence between the horns and woofers, you might consider the Classic Audio Reproductions T-1.
The CAR T-1 has a very efficient woofer but it doesn't go as deep as the Avantgarde woofer does, and the box is quite a bit larger. The midrange horn used in the T-1 also has a wider radiation pattern than that in the Avantgardes, so there is less discrepancy between woofer and horn. I would say the CAR's are a more coherent loudspeaker in the bass, while the Avantgardes are more coherent in the high treble. I think the CAR's have some of the best bass I've heard come out of a box - they sort of shattered my anti-reflex-box prejudices.
I don't sell either of these, but I admire both the Avantgardes and the Classic Audio Reproductions speakers.
Wow, Audio, your epistle is brief & staggeringly to the point. My hat off! Cheers,
Thanks for all the thoughtful comments. I really want to get over the bass issue with the Unos/Duos. Maybe in the end I will given the compelling presentation of these speakers.
I will make a suggestion that you could try. Have you tried placing them in the corners? This placement will simulate the radiation pattern of a bass horn, for your woofer box. It is possible that it may integrate better in this location. You will have to play with the controls on the bass box some more, because the corner load will add about 6 more db to the bottom end. There may be some tradeoff in imaging, though. Probably worth a try.
As a matter of interest, did you prefer the Duos over the Unos? I've heard convincing reports that the Uno (with 10" drivers in sub) as a more satisfactory design. I happen to have Unos as they were in my budget range and so well considered by Stereophile and others. I had not heard a Duo until recently abd I must say, I wasn't of the opinion they are any better, let alone £XXX better!
On the question of base coherence, I would agree it is not perfect, but anorther idea worth trying if you haven't yet done so, is to change the polarity of the bass unit. This is mentioned in the handbook (I think), but often overlooked.
I have found satisfactory settings for my subs and I'm very happy with the system generally. However I think that the bass performance varies a bit more rom one CD to another compared with conventional speakers. I find that on a few CDs the bass booms slightly more than I'd expect, but on most it's fine. Those few slightly booming CDs would possibly be less so on other speakers.
Overall, though I think they're fantastic speakers - I'm still looking for an ideal amplifier!
I auditioned the Duos a few weeks ago. The dealer (who is VERY good) had them set up in the corners as Twl suggests. In this configuration, I found the imaging distinctly sub-par for this class of speakers. Not that it was "bad", but it was obvious from 30 seconds that the other stuff he had (Avalon, Sonus Faber, ProAc are the ones I can remember) was imaging a LOT better. I found the bass to be somewhat light, but not as obviously "missing" as, say Magnepan 3.6's.
But personally, I didn't care for them primarily because they are REALLY immediate. 5th row set? No way! You are on stage with these AvantGardes! I found this to be too immediate and, I guess I would describe it as exhausting.
The Duos are so picky, if everything is not perfect they won't sound good. I have tried them all over the place in my room and have been ready to dump them, but after sufficient break in and taking the time to get them placed I love the way they sound, exhuasting no way.
I can see why there is so much distaste for these speakers, if everything is not just so they suck.
They certainly aren't the speakers for someone who doesn't want to put a lot of effort into getting them right. If anyone heard these setup right there is no way they wouldn't have to admit they sound pretty darn good. Chances are if you are hearing Avantgardes sound bad it's not the fault of the speaker itself. Which goes for most speakers.
Setup is everything
I listened yesterday Unos and newest SOLOs. The SOLOs are active monitors simply amazed me with excellent bass compared to Unos and tight organized sound with Capitole-2/Placette...
I was actually about to audition UNOs and listened to them more than one hour. Than after the dealer modestly offered me to listen to SOLOs and I said to myself Ge..., I'm already about to go home and almost have no time to enjoy them... Why didn't he offered me to listen to them first??
They need no poweramp, fully adjustable to the room with equalizer, height adjustable and don't need any amp. The built-in amp has a crossover unit for the subwoofer but these babes go down flat at 25Hz and look f..ng stunning... Oh, man!
So anyone who's dissapointed with Unos and Duos can now audition to SOLOs. They will retail soon at $8k/pr which is a bargain for a amp/speaker combo.
As a Duo owner, I have to agree with all comments regarding the need for careful setup in order to hear them as they are supposed to sound. Set up correctly they are most definitely World Class speakers. Fractions of an inch make an audible difference. When these speakers are set up properly, my experience is that the bass does integrate well with the rest of the system. Perhaps not with quite the speed and microdynamics of the horns, but as good as anything else i have heard. Also as an FYI, I recently did the wiring upgrade (2.2 to 3.2 status)and also added a second set of subs. Both of these added greatly to my musical enjoyment. The 2nd set of subs put the speaker into another class all together and made the bass exceptional(I have heard they are called "mini trios"). With the new Avantgarde Basshorns replacing trio subwoofers, a lucky listener may find a set of subs at a very reasonable price as i did. Good listening to all
Just a thought: It seems someone willing to use the Avantgarde horns/subs in a room that is extensively treated to absorb bass energy (lots of 4" wedge foam) could possibly get around the problem described (very well) by Audiokenesis. I am curious.... would this result in an environment that is too "dead" for the mid range and treble?