Mods for Avantgarde speakers

sdrsdrs, look forward to hear from you about the soldering tweak. this clip on connectors are bad for sound, not only in speakers but electronics as well!
had some wooden blocks built for the tweeters which I have put on the 225 subs which allow me to move the tweeters back in small increments. half cm matters if you get to the optimum point. the closer you sit to the speaker the further you have to move the tweeter back (if you are sitting on tweeter axis). have a look at the last uno nano review in stereophile, the step response. at 1,5 meter distance the tweeter signals arrived 0,75 ms too early which is around 26 cm!!!
I think with the trios you have to build your own stands for tweeter and mid horns so that you can individually move them back for proper alignment. not an easy task but no doubt sonically very rewarding!

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I have always wished that the factory speakers were time aligned. However, that discussion never went very far with the guys in Germany (whom I still greatly admire and count as friends, btw).

As such, it was a testament to how good they were in other areas that they could still be as musically involving with such disappointing driver alignments.

Over the years, I privately tried a variety of techniques to accomplish it (time/phase alignment of the treble horn to mid horn).

I managed to make it work, but I was never clever enough to completely overcome the additional issues of reflection from the treble horn, as more of its direct wavefront would be striking the bell of the mid horn.

Not only that, it was butt-ugly!

The general market would have been negatively impacted with my "solution".

So I finally gave up, because - even if it worked - even if it could be made to look less home-made, I couldn't get the factory to consider it as a serious discussion.

Probably because they'd been down that road many times previously.

One other observation - the closer you sit, the more noticeable this aspect is (sonically, and unfortunately - visually - as well).

At ear-to-tweeter driver distances of less than 10-11 feet, anything you can do to get these disparately placed drivers to "hang together" sonically is a good thing.

Certainly front-to-back tilt and/or speaker height become critical.
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I am struck by this issue with AG time alignment. Has anyone tried to time align in the digital domain?

I know the issue then moves into multiple amps etc. I have seen many systems that could do this. The problem then becomes one of the quality of the amps & the digital crossover.

Is the improvement really that great? It strikes me that time alignment is a can of worms. Surely at some point you still run into phase problems? Or is it that to get the tweeter & mid closer in alignment is enough? My seating position is around 4.5-5m away.

Hornguys, I agree with your comment re butt ugly. my solution with the wooden blocks certainly is but I don't care. I don't have a problem with reflections from the midrange horn. have measured the response before and after time alignment and there is no difference.
I also find it amazing how much of a difference it makes to time align the horns with the subs. I'm using digital delay for that which I can adjust on the fly with a few a mouse clicks. even at a xo of 200 hz a few cm can easily be heard.
everybody who is interested in this subject should look at john atkinson's step response measurement of the uno nanos and read his comments!!

Chadeffect, aligning tweeter with mid horn would certainly be a major improvement. best would be to align all 4 drivers in your trios but this is a daunting task indeed

Duomike,

I have read a reasonable amount about time alignment & it strikes me there is little gain vs all other issues. Probably why AG do it that way.

It may be easier to time align a 2 way, but once you get to 3 & 4 ways it gets very tricky as off axis response, beaming at various frequencies, room interaction & positioning becomes very difficult deal with. It strikes me the only sane way to attempt alignment is in the digital domain.

I have a friend who has a DAC/Pre which has built in room correction/4 way digital xover. I will see if I can borrow it & have a play. My problem is a multichannel amp. 8 channels & all the cables... I will try & organise it over Xmas if I can & report back. Looks like a lot of work!