|
Home » Sponsored » Pi Speakers » what design can i throw 8 jbl 2206J's in?
| Push-pull versus shorting rings [message #51325 is a reply to message #51324] |
Wed, 08 August 2007 10:08   |
 |
Wayne Parham
Messages: 18730
Registered: January 2001
|
Illuminati (33rd Degree) |
|
|
I like the push-pull configuration too. But shorting rings work very well at midbass frequencies up. Push-pull works best as frequency drops, at least the version I'm talking about, which is a pneumatic/acoustic implementation where two drivers are mounted physically opposite and driven opposite in order to cancel mechanical asymmetry.
The reason for the shorting ring's "preference" to higher frequency is that it is an electro-magnetic device. Just like coils have to be large to work at low frequency, so do shorting rings, which are essentially single-turn coils.
Mechanical push-pull works best as frequency drops. This is because it is summing acoustically, in the air. So the drivers have to couple together, and this gets increasingly harder as frequency goes up. The drivers just aren't coupled together as well at higher frequencies because they grow further apart in phase. The lower the frequency, the closer in phase the two drivers are.
As to size, we're making a prototype 10π right now. But it isn't a midbass horn, it's a hornsub just like the 12π. It's smaller and easier to carry, which is attractive for smaller shows. The 12π is fine if you use a truck with a ramp, because it is designed to fit right on it. But if you have to carry them across a field, it's a drag. So the 10π is designed to address this.
The 10π basshorn subwoofer is half the size of the 12π, and is designed to be used in complementary pairs. It incorporates push-pull drive when used in compementary pairs as designed, but the trade-off is that it may not receive as much distortion reduction from push-pull drive as the 12π does because the drivers are further apart. Summing is done at the mouth, not the throat. I expect distortion reduction to be good at very low frequencies but that it becomes less effective as frequency rises. We'll be able to quantify this more definitely after measuring the prototype.
|
|
|
|
Current Time: Sun Jul 21 10:23:55 CDT 2024
|
Posting Rules
Members
Search
Help
Register
Login
Get a T-Shirt!
