|
|
Re: Horns, transmission lines and reflex cabinets [message #21199 is a reply to message #21187] |
Wed, 10 August 2005 13:41 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Retsel
Messages: 23 Registered: May 2009
|
Chancellor |
|
|
This is not my experience comparing my Lowther DX4s in Hedlund Horns versus Open Baffles. In Hedlund horns, the DX4s have an average efficiency of over 100 db (I think 101 db). In Open Baffles, I think that Dick Olsher claims an efficiency for the DX4s of something like 98 db. In open baffles, I use a single inductor as a first order filter to roll off the high frequencies from 500 hz and above. I then have a fairly flat frequency response from 150 hz to the high frequencies (~10 khz). In Hedlund Horns, the DX4s are flat all by themselves (no filter needed) from 70 hz to the high frequencies (~10 khz). Thus there are no losses in inductors, and I can get down lower. Retsel
|
|
|
|
Re: Horns, transmission lines and reflex cabinets [message #21203 is a reply to message #21201] |
Thu, 11 August 2005 07:15 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Retsel
Messages: 23 Registered: May 2009
|
Chancellor |
|
|
Except that your post is contradictory. Bringing up the bass IS efficiency increase (more sound and wider frequency response with the same watts). Rather than increase the efficiency of the upper registers, the BLHs don't use crossover components which REDUCE efficiency in other designs. This is why BLHs are more efficient. Retsel
|
|
|
|
|
Re: Horns, transmission lines and reflex cabinets [message #21206 is a reply to message #21205] |
Thu, 11 August 2005 10:05 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
![](http://audioroundtable.com/forum/images/custom_avatars/5.gif) |
Wayne Parham
Messages: 18758 Registered: January 2001
|
Illuminati (33rd Degree) |
|
|
I think your assessment is correct. But I also think it's important to look closely at this, because small basshorns are the same thing as tapered pipes in all but name. Bass-reflex speakers provide augmented bass output too. So to talk about the differences, one must first look at the similarities. There's a huge amount of overlap in each of these designs.Each will have Helmholtz resonance, determined by the dimensions of the exit hole and the volume of the cabinet. Helmholtz resonance is normally associated with bass-reflex speakers, but it is just a physical property that happens when you have a chamber with a hole in it. There will also be standing wave modes, determined by cabinet dimensions, component placement and geometry. And there may be some horn action, depending on flare rate and environment, like corner loading. So there will be each of these properties, whether the speaker is called a reflex system, horn or transmission line. The overlap of each of these makes them more similar than different.
|
|
|
|
|