Avantgarde's are Great but Bass Integration?

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.