High Efficiency Speaker Asylum

Loop check for Reactance Annulling

84.105.197.130

mdg

Hi all,

Does anybody know if you can relate an acoustic measurement (impedance or frequency response) to the subject reactance annulling.

How you can be sure you have a hornsystem with the most optimum alignment in terms of effiency?

gr. Marcel

Follow Ups:

RE: Loop check for Reactance Annulling - Saturntube 06:04:32 05/03/16 (0)
There are some big threads about that here, do a search, a lot of contradicting opinions.
RE: Loop check for Reactance Annulling - Bill Fitzmaurice 13:30:24 04/29/16 (2)
> How you can be sure you have a hornsystem with the most optimum alignment in terms of effiency?
Model it in HornResp. The effect of altering the rear chamber size, or anything else for that matter, is easily seen. If you want to see the optimum result possible with a given driver use the System Design tool. If you want to check whether an existing enclosure meets the design specs compare the measured impedance to the predicted.

Edits: 04/29/16
- RE: Loop check for Reactance Annulling - mdg 06:24:39 05/01/16 (1)
  Hello Bill,
  
  Thx for your reply.
  
  Would the resonance curve in the impedance plot be less wide,
  because the hornis more resistive?
  
  There are a few papers about the subject reactance annuling but none of them a talking about how this can be checked with measurements and what to look for.
  
  gr. Marcel
  - RE: Loop check for Reactance Annulling - Bill Fitzmaurice 08:47:07 05/01/16 (0)
    To simplify what happens without the complex math, the air mass in a horn adds to the Mms of the driver, effectively reducing its resonant frequency. If said resonant frequency is too low the horn loses sensitivity near the cutoff frequency. Reactance Annulling is a three dollar term used to describe using a small rear chamber to raise the effective driver resonance back up to where it's the same as the horn cutoff frequency, giving higher sensitivity near Fc. When the rear chamber size is correct there will be a major impedance peak at Fc. When it's too large the peak will be below Fc. When the chamber is too small the peak at Fc has value drops, or disappears entirely.

Post a Followup:

FAQ

Post a Message!

Forgot Password?

Moniker (Username):
Password (Optional):
	Remember my Moniker & Password (What's this?) Eat Me
E-Mail (Optional):
Subject:

Message:	(Posts are subject to Content Rules)

Optional Link URL:
Optional Link Title:
Optional Image URL:
Upload Image:
E-mail Replies:	Automagically notify you when someone responds.

To view your new posting or follow-up, click on the RELOAD or REFRESH button on your browser.

This post is made possible by the generous support of people like you and our sponsors:

Kimber Kable