Transmission Line vs Horn

[Mike Gann]

Hello there,

So, I have an SA-8 v.2 laying around and I'm thinking about making a home audio sub with it. I know it's probably not the best sub to not use in a car but I'm just doing this for fun, to learn, and not spend that much on it. I've been reading into T-lines for a while now, but I know nothing about horns. essentially they're of the same family I'm guessing. So for large room application and bass extension would I be better off with a Tline or a horn enclosure? Space isnt exactly an issue, another reason I'm not putting this in a car. Also whats the best way to power something like this? I only have car amps laying around. Will any old stereo system work for power or should I look into an investment of sorts?

[White Lightning]

I'm not sure how these bass guys are going to say how to do it ... but this is what I would do ...

Build a downfire sealed enclosure with maximum recommended dimensions and port that thing at 20 htz ... or at least the lowest frequency that driver can handle without going ballistic ...

[Mike Gann]

I'm not sure how these bass guys are going to say how to do it ... but this is what I would do ...

Build a downfire sealed enclosure with maximum recommended dimensions and port that thing at 20 htz ... or at least the lowest frequency that driver can handle without going ballistic ...

sealed/ported enclosure?

no I think i'm going to either tline or horn, typicial ported won't be much fun. Besides at those numbers it's not much different from a tline, it doesn't require much box but to tune a small space to 20 would require a long port. Since it's only an 8in, and space isnt an issue, the most efficient kind of box is what I'm looking for.

[Triticum Agricolam]

A T-line pretty much does the same job as a ported box. They both tune the backwave to compliment what comes off the front. You will get similar performance out of a T-line as you would out of a ported box of roughly equal dimensions and tuning. Horns are a little different beast. I've never had the motivation to try to design one for myself, but I've built many that other people have designed. My understanding is they usually take more than one try to get something decent.

I know this is probably not what you want to hear, but a SA-8v2 just isn't the right tool for what you want to do. It isn't going to have good low end output in a t-line and it didn't look good for any horn designs either. What you need is a hammer and what you have is a crescent wrench. You can try to use it like a hammer but it won't be pretty. Likewise, if you try to put that SA-8 in a horn or T-line you will get noise, but it won't be music.

My suggestion is if you want to experiment is to pick up a $60 Infinity 1060W and build a Cinema T-6 tapped horn for it. Here is a link to the sub: http://www.amazon.com/Infinity-Reference-1060w-1100-watt-High-Performance/dp/B0028APNZ2

And here is a link to the horn design: http://www.avsforum.com/forum/155-diy-speakers-subs/1358033-lilmike-s-cinema-t-6-a.html

If you build that you will at least end up with something useful and that works decently well.

[Mike Gann]

A T-line pretty much does the same job as a ported box. They both tune the backwave to compliment what comes off the front. You will get similar performance out of a T-line as you would out of a ported box of roughly equal dimensions and tuning.

Yes I'll get similar performance if its similar size, thats why I said I would just jump for the tline instead. A Tline will be much larger then a ported enlcosure, like I said space isnt an issue. It's like no one reads what I said, I'm not doing it cause it's the right thing for the job, it's just the victim that I have laying around. If I have to buy another sub then I'll just scratch the project.

But the question remains, since I don't know how to horn, which enclosure would be best for a large space

[Mike Gann]

My suggestion is if you want to experiment is to pick up a $60 Infinity 1060W and build a Cinema T-6 tapped horn for it. Here is a link to the sub: http://www.amazon.com/Infinity-Reference-1060w-1100-watt-High-Performance/dp/B0028APNZ2

Ha I just realized you've suggested this sub to me before, but the 8" version. Is it because they're cheap?

[Triticum Agricolam]

Yes I'll get similar performance if its similar size, thats why I said I would just jump for the tline instead. A Tline will be much larger then a ported enlcosure, like I said space isnt an issue. It's like no one reads what I said, I'm not doing it cause it's the right thing for the job, it's just the victim that I have laying around. If I have to buy another sub then I'll just scratch the project.

But the question remains, since I don't know how to horn, which enclosure would be best for a large space

I read exactly what you said, the problem is you aren't understanding what I'm saying. I know you can build a big T-line, you can also build a big ported box and do the same thing. There is no performance advantage to a t-line vs a ported box.

I know you want to use the sub you have, but it's going to perform badly in a t-line for home audio use and it's going to perform horribly in a horn. So your choice is between "bad" and "horrible". I'm afraid all you would learn from the project is how to do something incorrectly.

I recommend those subs because I didn't think you wanted to spend much money on the project, those subs perform very well for what they cost and are pretty flexible in how they are used.

[White Lightning]

I'm not sure how these bass guys are going to say how to do it ... but this is what I would do ...

Build a downfire sealed enclosure with maximum recommended dimensions and port that thing at 20 htz ... or at least the lowest frequency that driver can handle without going ballistic ...

sealed/ported enclosure?

no I think i'm going to either tline or horn, typicial ported won't be much fun. Besides at those numbers it's not much different from a tline, it doesn't require much box but to tune a small space to 20 would require a long port. Since it's only an 8in, and space isnt an issue, the most efficient kind of box is what I'm looking for.

Laugh at me all you want, but I've built several amazing home theater systems in my day ...

Besides, It was just a suggestion. Good luck with your project Sir.