Altec Lancing speaker build

**bryans** · July 27th, 2013, 11:43 PM

Hello, I was told about this site from some good guys at audio karma. I hope there is someone who can help me with a few questions I have. I recently got a hold of some speakers that are in good shape. They are 806 A drivers with H 811 B horns and 416 A woffers. I also have N-800-G dividing networks. I have built some cabinets for themand they sound really good, but I thihk I can do better. The lower register is lacking. I tried disconnecting the crossover and this seemed to help quite a bit. Is this a bad idea? Is there another crossover I should use. I also have the horn and woffer in the same cabinet I'm notsure if that is proper either and finnally should the cabinet be ported and insulated? I'm sure I'll get an earfull for the way I've gone about things but I just couldn't wait to hear them. That was before I learned how popular these speakers where, thanks for any help you can give me. Bryans

**Phil-G** · July 28th, 2013, 09:29 AM

any one have any suggestions here?
i for one would like to see a picture or two.

**zelgall** · July 28th, 2013, 09:51 AM

Details of the cabinets would be a good place to start. How big, dimensions, port size etc.

**cradeldorf** · July 28th, 2013, 02:42 PM

You'll want to keep a crossover on the horn to keep from destroying the Diaphragm. Low frequency won't get damaged. Horn and woofer in the same cabinet won't hurt anything since the horn is a sealed unit. Just don''t take the back cap off the horn and try to run them as the bass would not be too friendly to the phragm...providing there is no loading caps in the drivers..

**bryans** · July 28th, 2013, 03:48 PM

Thanks for your response. The cabinets are two feet wide, three feet tall, and 17.5 inches deep. They are constructed out of 5/8 particle board.

**Alien_Shore** · July 28th, 2013, 07:03 PM

The 416A is rated 20Hz to 1.6KHz.
Vas is probably going to be around 25 CF...but I didn't calculate that.
I think your box (~7.4CF) is going to be pretty close to what you need for the 416A, if you use a bass reflex alignment.

**bryans** · July 28th, 2013, 08:03 PM

Thanks for the info Mike, I've got to tell you it's over my head. I can tell you that I love good sound, always have. I'm blown away by these speakers and just want to do right by them. I don't know what a bass reflex alignment is. Does that have anything to do with a port in the front of the cabinet? Should I use something similiar to the port that is on the model 19 cabinets? Are there any drawbacks from not using the n-800-G dividing network on the woffers? Finally should I use about a 1 and a 1/2 inch insulation on the sides and back? Thanks again for your time. Bryan

**Alien_Shore** · July 29th, 2013, 11:53 AM

Originally Posted by bryans

Thanks for the info Mike, I've got to tell you it's over my head. I can tell you that I love good sound, always have. I'm blown away by these speakers and just want to do right by them. I don't know what a bass reflex alignment is. Does that have anything to do with a port in the front of the cabinet? Should I use something similiar to the port that is on the model 19 cabinets? Are there any drawbacks from not using the n-800-G dividing network on the woffers? Finally should I use about a 1 and a 1/2 inch insulation on the sides and back? Thanks again for your time. Bryan

You're welcome.
Bass Reflex alignment is a.k.a. vented cabinet. Check out this old pamphlet for a good beginner's introduction to such things:

Loudspeaker Enclosures

Yes, you will want to get some help in calculating and/or adjusting the proper tuning of the cabinet by choosing the correct size and depth of the port in the cabinet to help reinforce the low frequency response of the system.

As far as the crossover, the main drawback to not using the crossover with the woofer is that you'll be allowing the 416A to run full-range, and it will generating the same frequencies as your HF horn will and there will be nulls, cancellations, and other acoustically undesirable effects. By far, the best thing to do is to use a properly designed crossover for your drivers and cabinet that controls the output of the individual drivers and creates a smoother combined frequency response.

The insulation or "stuffing" you put into the cabinet acts as damping, which has all sorts of effects on the system's sound. Here's a web page that provides a brief introduction:

Cabinet Damping

Controlling the reflections within a bass reflex cabinet is almost always desirable. How much, and where is a matter of design objectives and personal preferences. You'll likely need to do some reading on the topic to understand what you're doing, and then experimentation until you get the sound you want.