[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

I will be following the progress on the double stack ESS AMT-1's with wings. Very Interesting and informative.

 

Kenny

[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

The 2 FH-1's per side that I use in my room in the corners will go down to 35hz. In a big room free standing probably 90hz or 60hz or whatever. But in my room 35hz. They say the same thing about Atec A7's that they will only go to like what 45 or 50hz. In my room 35hz. I had a radio engineer who also had his own band who sold me the FH-1's tell me I was crazy and was boosting or equalizing the bass to get the 35hz and that it would unload the woofer and ruin or blow it. He is right of course. But, But (I meant to put in 2 Buts) I am not equalizing them or boosting them.

 

I have run the FH-1's in series bi-amped with a horn mid-tweeter. I have also run them tri amped with a amp on each FH-1 and a horn mid-tweeter. Then run one FH-1 to like 100 or 200hz and the other to like 800hz. That way you can mess around with them and tailor them.

[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

14 hours ago, Chris A said:

This is already addressing the initial questions that I was first beginning to ask yesterday when I asked the question (but hadn't yet posted it--needing the continue through all of your comments).  Have you tried tacking up absorption material on the side walls next to the AMT-1s and woofers/horn?  This should significantly strengthen your phantom center image performance in-room.

No, I haven't put up any absorbtion material on the side walls. It would definitely help with sound bounce and smear. But by putting the AMT-1's on their sides they won't bounce the sound off of the side walls.The 828's I have are on wheels so the cabinets sit up 47 inches. If I had the AMT-1s setting normally and not on their sides they would be firing over my head because my ears sit 32 inch off the floor. And I angled the inside AMT-1's to fill in the center image.

 

Without wing extensions and by splaying the inside AMTs toward the center between the loudspeakers, the effect of acoustically loading the ribbons is decreased relative to stacking them vertically or horizontally in a straight line configuration, so you probably are still dealing with widening polars below 2 kHz. If you try stacking them vertically, add wings, and most importantly--add absorption the the side walls (at least 2 feet wide on each side and the height of the loudspeaker), you might like them a bit more in that orientation/configuration. 

You are right by angleing them in it does decrease the loading. But most people only use one per side anyway. Adding wings or a horn on the front will lower the frequency they will reach. But at what cost. Will they still sound strident? I don't know.

I could add absorbtion material on the walls but I would still have the vertical dispersion problem if I had them facing straight up as designed. If I could get them at ear level it would be a whole different ball game. People are going to have the same problem if they put them on top of Khorn's, Jubilee's or Jamboree's.

I will say my room is completely different then a lot of peoples. My room is small and that is what I have to work with.

 

Chris

 

[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

14 hours ago, Chris A said:

 

The front wave is splayed outward, but the backwave will be aimed at a point on the rear wall, and the bottom wing of each AMT-1 is reflected off the top of the loudspeaker...thus screwing up the backwave pattern pretty much completely (assuming that a consistent backwave pattern is important).  And there will be coverage gaps between the drivers aimed at different splay angles.  The above photos indicate to me that ESS simply absorbed the backwave, thus killing the dipole effect in favor of the splay front wave (on its side).  Laying them down and splaying them looks like it creates a very complex polar coverage pattern.

I think they absorbed the backwave as inticated in the picture. It looks like they worked on the vertical problem of dispersion and controlled the horizonal dispersion.

 

Can you describe how you didn't like the sound? Were the AMT-1s fully broken in (i.e., at least 40 hours of normal listening volume) when you tried all of this?  How were the speakers located in-room relative to the walls/corners?  Were there any furniture/equipment racks/TVs in the middle between the loudspeakers at the level of the AMT-1s? (I.e., a picture of your setup would be nice to have). 

I didn't like the diffuse sound and vertical narrow dispersion. Side wall sound absorbtion may cure this problem.

Yes the AMT-1's are fully broken in. The Altec 828's are in corners of the room.

The AMT-1's are on top of the 828's on the inside front edge of the 828's..

There is a rack and equipment between the speakers. It sticks out about the same amount as the 828's.

 

Dimensions (length x width x height)?

10.5 foot X 13.5 foot. Speakers on the narrow walls.

 

I can see why you wanted to fill the horizontal dispersion of the AMT-1s in their sides.  However, half the polar coverage of the AMT-1s is constrained by laying them down sideways.  Have you moved them forward to the front of the cabinet such that they illuminate the floor, too?

Yes, half the rear polar coverage is constrained or blocked by the 828 cabinet top. They are on the front edge and on the inside corners of the 828's. The 828's have towels covering the entire top of the speaker cabinet.

They are on the front edge of the cabinet so they are illuminating the floor.

 

It's difficult to interpret this sentence unless you're using some sort of midrange. Your system (A700-828) I thought looks like this, and is typically used as a two-way with some sort of segmented or cellular Altec HF horn on top:

The 828's are front horn loaded and the back is ported. So the front horn is much louder than the back. To compensate for that the front horn should be padded down to match the back ported cabinet. If not there will be little bass because the horn overrides the bass. Once adjusted the mids are balanced with the bass. In my room the 828's go down to 35hz strong with a faint 30hz available, unequalized.

The 828's horn is the midrange so to speak. A lower frequency midrange but a midrange. I shelf down the horn starting at 240hz and above.

So to match the 2 AMT-1's to the 828's I padded down the AMT-1's.

 

That's what I have. 828H

 

 

So you can hear the effects of flatter phase response using first order crossover filters?  This isn't a surprise to me as I found the same thing last year with all my 5.1 array loudspeakers (Jubilees, K-402-MEH center, AMT-1/Belle bass bin surrounds, TH subs).

I can hear the flatter phase response of a first order filter. It also has more ambiance.

 

Is there a reason why you didn't cross over at a lower frequency?

I tried lower frequencies and there is a strident sound to the AMT-1's that I didn't like. Same problem with the 828”s if I cross them over anywhere above 1200 hz. There is just a distortion I don't like.

 

Thanks for sharing all this.  It's an interesting adventure just reading what you've tried and like/dislike.

 

Chris

 

 

[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

5 hours ago, ClaudeJ1 said:

I see no reason for stacking FH-1s, since they are at 104 db/w with a 4 ohm driver inside. But stacking and winging the AMT's makes a lot of sense and difference in performance should be obvious. Turning them on their side for a 30" height, makes more sens for sit down sweet spot listening.

 

There is a lot you can do with dual FH-1's per side. Saying you see no reason for stacking FH-1's is like a person saying (and I am not saying you said this) there is no reason for a Jubilee or Jamboree with dual woofers.

And I said 30 degrees angled in, not 30" height. And that is why I angled them in and put them on their sides is to widen the horizontal dispersion and to keep the outside ones from bouncing sound off of the side walls. I have the Altec's in corners for bass re-enforcement so the Heil's are also close to the side walls. And I sit in one spot all the time.

And stacking the Heil's straight up instead of sideways will help with vertical dispersion but won't cure it. Horizontal dispersion is not a problem.

[Double Stack ESS AMT-1 with Wings--Possible Kit for Heritage]

I bought four of the Great Heils from ESS when they had their sale for $140 each. I played around with them on top of my Altec A700 828 cabinets equipped with Altec GPA 416-8C drivers. I tried the Heils stacked, both straight up and one laying on it's side. Then putting them side by side, but one straight up and laid the other on it's side. With them side by side and one laid down on it's side, I tried the laid down one on the outside then on the inside. And then I tried both on their sides, side by side. Finally I have settled with them on their sides, side by side with the outside ones straight forward and the inside ones about 30 degrees angled in. It gave the blend I wanted without the directional properties horizontally. Because on their sides they have good vertical dispersion but not good horizontal dispersion. My room is small and I just didn't like them straight up like they were designed. I also tried tweeters but took them back out as they weren't needed as far as i am concerned. Look up the ESS AMT6 to see how ESS designed the AMT6. Maybe if I could get them more at ear lever I would like them stacked straight up.

 

I used REW and set the miniDSP parametric EQ. I still had to tweak the miniDSP to lower the Altec horn and Heils as both were too loud or hot. Added delay to the Heils and it is sounding good. I crossed over the Altec's at 1150hz 6db and the Heil's at 2000hz at 6db which gave a -4 db at 1514hz. I tried all kinds of crossover combinations from 500hz to 2000hz 48db, 24 db, 18db, 12db and have settled on the 6 db.

 

My next thing to do is roll out the Altec's and roll in four Peavey FH-1's, two per side with Eminence drivers and see how that sounds with the Heils.

 

I did put my horns back on top of the Altec's and took the Heil's out but that didn't last long before I went back to the Heils.

[I Hate, Hate, Hate, Hate Those Crummy...]

Now that's funny. And then there's the stupid sticky glue on the tape that stuck to the jewel case. What a pain.

 

And at least on vinyl you can read the words to the song.