Audio Audit reveals possibly cracked Forte 2 box...

[Tyson68]

I moved about a year ago and basically slapped my system

together to get it working, after I got moved in I completely forgot about it

and never went back to be sure everything was the best it could be.

Well, I finally had enough of the imaging

issues with voices off center to the right, a center channel that had to be +6

db louder then the rest of the system, no soundstage at all beyond the

speakers, no bass (from forte 2’s no less), and a left speaker that seemed to

be possessed as it kept turning around slightly every few weeks.

So a couple of weekends ago I took apart my entire system

and put it back together, minding cable paths, cleaning connectors,

dusting/cleaning/de-spidering (arachnid spiders that is, daddy longlegs absolutely

LOVE the passives).

As I took it apart I found the following:

1. Left

   Forte 2: Riser was warped causing it to be unbalanced, negative speaker

   wire nut was loose, positive wire was corroded, pushed in the passive to

   check air tightness and the woofer moved but immediately went back, I’m

   talking .5 of a second is all it stuck out. Thinking I cracked the box

   somewhere I didn’t want to look at it anymore and moved on.

2. Right

   Forte 2: The terminals were loose, both wires were corroded, and the air

   tightness test was about 1.5 seconds for the woofer excursion. Great,

   maybe two cracked boxes.

3. Center

   Academy: Out of phase; wired it wrong, clunking inside box; removed the

   woofers and found one bucking magnet broke off and the wires were not even

   attached to it (my fault on the wires though, I removed the same woofer a

   few years ago when I first heard it clunking, the bucking magnet was still

   on (loose) and I couldn’t remove it, looks like I forgot to put the wires

   back on).

So, after I fixed everything and got it back together and

tested, I finally got the sound I remembered before the move, but it was still

lacking bass. Based on my research here I think its time to replace the caps.

I’ve been dealing and messing with audio since the

late 70’s, I should know better. But even after 30+ years I still messed up the basics.

I did get

the Forte 2’s air tight the best I could, got the woofer to stick out 2.5

seconds. And when I tap on the passive it immediately registers on the woofer

now. My research here said 3 seconds, but I don’t know where I’m going to get that

last .5 of a second with out putting a smoke machine inside it to see where it

leaks.

Actually, the smoke/fog machine is not a bad idea, and probably

the best way to be sure the box isn’t cracked, any thoughts?

[moray james]

Tyson: welcome aboard. I will be the last person to argue with about you upgrading your networks, I will go farther, get better networks get better caps and most importantly get better inductors and a better set of auto transformers. So I see you and raise you. That all said I think that you should play with your positioning to see if you can correct your current situation. You can do you worst and then switch speakers left for right to see if there is a change, if the speakers are fine there should be no difference. I doubt that your caps are just all of a sudden acting so badly. You have a new room with walls and doors that are in different places and your room is not likely symetrical either. So play away and see if you can position the speakers to achieve your goal first. Then go nuts on your speakers. While you are at it switch out to all Ti diaphragms and brace the bits out of your cabinets. If you want more bass extension (about 3-4 Hz) you can add some dead weight to your passive radiators about 3.5 ounces will work well.There are a lot of things that you can play with if you get the itch. Oh and build or buy a quality set of four post stands to raise your speakers so that the mid horn is centred at your seated ear level that will help stage an image a lot. Best regards Moray James.

[Tyson68]

I currently have them 16in from the back wall and 8' apart.

I think I'll start with the triangle approach for initial setup, see how it

is and then adjust from there.

I know I can get the cabinets to ring if I hit them on the sides, but when I

play test tracks from Stereophile Test CD 2, I can't hear the ring or feel it.

So I'm not sure if upgrading the bracing would do anything sonically at the

65-75db listening level i use 99% of the time. Of the people that have upgraded

the bracing for their Forte 2's, what was immediately noticed?

The Ti upgrade for the tweeters is in the works.

I can use lead fish weights if I want to try adding weight to the

passive right? Assuming I put them on the back side.

The mid-range at ear level is an idea I want to try, just need to run the

numbers to see how high I have to get them.

No thoughts about the Fog/Smoke test? We do it all the time to check for

vacuum leaks in car engines. Guess I'll just have to check and see if what's

used for checking vacuum leaks will eat away my drivers or not.

[moray james]

Tyson: cabinet brace work always helps and it make no difference what level you play at less noise is less noise greater dynamics will always be noticed. I like to use two large steel flat washers for the dead weight I found two large washers that weighed almot exactly 1.25 ounces each I glued them in place with a small amount of five minute epoxy adhesive. Fast easy and simple to remove if I wanted to. Most folks will have their ear at between 36 and 40 inches off the ground too may variables so just measure with a tape or have a friend measure while you sit so they can estimate for you from your side. Does not have to be perfect. I like to use an equilateral triangle to set up speakers and I like to look straight down the throat of the horns from my listening position. Best regards Moray James.

[Tyson68]

I'm pretty sure i got room issues after moving the speakers around a bit.

I noticed that when i stand up in the listening position, i would rate the bass level as a 7 out of 10.

When I sit back down, the bass drops to a 3 out of 10...it just disappears.

I have a typical setup with a LCD Tv on the wall, an equipment rack under it that holds my academy and the rest of my system and the speakers on either side. The floors are wood, but i have carpet in front of the speakers all the way back to the listening position (just area rugs).

The only place i can think of starting is to remove the equipment rack and see if its blocking the bass and directing it upward.

But i think you might be right, I may not need new caps yet.

[moray james]

Quote: I may not need new caps yet

Well your speakers will run with the caps that they have but they will sound much better with good new ones. Best regards Moray James.