Altec 416b MLTL, design by GM

[westend]

I hope GM is OK with posting this on yet another audio Forum but my intention is to show what a great design this is for those with the Altec 416b and to compliment the designer, again. GM has hit one over the fence with this big MLTL.

Background: I posted on the Altec User's Board about a taller design for Model 19 components a couple of years ago in this thread. At that time, GM worked up an MLTL design that put the woofer at a center height of 44". This was to accomodate my listening space, more than anything. The original width, depth, and port opening of the Altec Model 19 cabinet were used. It took me a couple of years to finally get everything built but the cabinets are now done.

The finished exterior height of the taller cabinet is 54 1/4", interior height dimension is 52 3/4" since I chose to double the top and bottom panels. The interior volume is very close to 16.4^ft.. I have the original 811 horn/802g driver mounted on a sled on top of the cabinet. A Heil AMT-1D tweeter is also on the top of the horn sled, used as a super-tweeter to add some sizzle.

Build threads are also posted here, at Audiokarma and here, on the Altec User's Board.

My thanks, again to GM for his design expertise and the time he took to guide me through the build process. The cabinet is more appreciated every day, the bass presentation is greatly enhanced by the position of the woofer and the TL action. The lower end roll-off is much superior to the original Model 19 cab and the west-coast hump is now gone, replaced by the better TL presentation. This big cabinet allows the 416b to really shine.

[angeloitacare]

This horn has some wonderful tipical horn honk. Replace it with wood radial or tractrix or lecleach horn, and you will enhance midrange reproduction significantly.

[westend]

Originally Posted by angeloitacare

This horn has some wonderful tipical horn honk. Replace it with wood radial or tractrix or lecleach horn, and you will enhance midrange reproduction significantly.

A horn upgrade is anticipated and I am leaning towards the Lecleach style.

As for horn honk, I'm not hearing it I also don't have any "ringing" that some others seemed plauged with. This might be due to how they are driven. I am triamping this system, the midrange is low passed at 1100 hz and high passed at 8 khz using an active crossover with 24db slopes.

[angeloitacare]

Originally Posted by westend

A horn upgrade is anticipated and I am leaning towards the Lecleach style.

As for horn honk, I'm not hearing it I also don't have any "ringing" that some others seemed plauged with. This might be due to how they are driven. I am triamping this system, the midrange is low passed at 1100 hz and high passed at 8 khz using an active crossover with 24db slopes.

I had the Altec 19's. I did not perceive that horn's shortcomings, until got a ACR H-220 wood radial horn, and made direct comparisons.

[westend]

Originally Posted by angeloitacare

I had the Altec 19's. I did not perceive that horn's shortcomings, until got a ACR H-220 wood radial horn, and made direct comparisons.

We are in agreement, the 811 horn has shortcomings. I have listened to some exceptional horns in the past couple of years, the local audio scene has more than a few guys using wood and other types of horns.

FWIW, I nearly bought a giant timber lathe for producing wood horns but the investment in time and expense was prohibitive for such a narrow use. I am still thinking of building some wood horns.

What driver do you use with your ACR H-220 horns, Angelo?

[angeloitacare]

Originally Posted by westend

We are in agreement, the 811 horn has shortcomings. I have listened to some exceptional horns in the past couple of years, the local audio scene has more than a few guys using wood and other types of horns.

FWIW, I nearly bought a giant timber lathe for producing wood horns but the investment in time and expense was prohibitive for such a narrow use. I am still thinking of building some wood horns.

What driver do you use with your ACR H-220 horns, Angelo?

I am not using this horn anymore. My system has evolved a lot since then ( i had Altec 19's until 2002 ):

my blog , many pictures - Audio Voice Acoustics

[westend]

Angelo, to say your system has evolved is an understatement, very nice setup! I followed some of your links and will be looking around at Audio Voice Acoustics about horn based systems, thanks.

[TerryO]

Westend,

Until you get to the wood horns, just get a few bricks of Duct Seal (or Oil-based modeling clay) and use that to stop any ringing. Either product is removable, as well as easily applied and works extremely well. However, as you already have a wood bezel around the edge of the mouth, it may already sound pretty nice.

Neat Project,

Best Regards,
TerryO

[Cal Weldon]

It is really only the "lips" that you must worry about. And, if you damp only the top one you have effectively damped them both if the horn is stock and the vanes have not been altered. The mounting flange on the other hand has little effect on the damping. For a quick and dirty, fill the cavity on top with water.

[TerryO]

Originally Posted by Cal Weldon

For a quick and dirty, fill the cavity on top with water.

Or in Cal's case...Beer!

Best Regards,
TerryO