Speaker design challenge: 105db 20 - 20k at listening position

[paulspencer]

This is a future upgrade project, for both music and home theatre. My goals are:

*105 db peaks at listening position (115 at 1m) without a little extra output in reserve if possible
*20Hz - 20k response
*room interaction is a critical factor so I would count out a conventional floorstander with monopole subwoofer - controlled directivity and polar response desirable
*I prefer a relaxed sound that is a little more forgiving than an ultra high resolution that makes typical recordings sound bad

How would you approach this challenge? What would be your design?

[paulspencer]

Some inspiration

http://www.dnaudio.com/index.htm/
http://www.legacy-audio.com/2004/whisper.html


http://ldsg.snippets.org/HORNS/unity2.html


I've been considering some kind of combination of some of the following ideas:

- large coax drivers like Adire HE12
- point source arrays with 4 mids in formation around a central tweeter in a waveguide - similar to Legacy Audio with their Helix and Whisper speakers
- dipole from 30 - 200 Hz
- open baffle midrange
- CD horn (is it possible to get this sweet sounding?)
- unity horn clone

[soongsc]

Originally posted by paulspencer
This is a future upgrade project, for both music and home theatre. My goals are:

*105 db peaks at listening position (115 at 1m) without a little extra output in reserve if possible
*20Hz - 20k response
*room interaction is a critical factor so I would count out a conventional floorstander with monopole subwoofer - controlled directivity and polar response desirable
*I prefer a relaxed sound that is a little more forgiving than an ultra high resolution that makes typical recordings sound bad

How would you approach this challenge? What would be your design?

105dB for 20Hz is asking doe a large room.

[SY]

Originally posted by soongsc



105dB for 20Hz is asking doe a large room.

Why is that?

[paulspencer]

105dB for 20Hz is asking doe a large room.

My current system achieves this easily with a pair of sealed subwoofers. In vented boxes they could approach 120db. This is the easy part. If you want more bass, you can easily add more subwoofers, and there are benefits in smoothing in-room response. However, you can't do this at the top end! It seems to me that the treble is the difficult part ...

[phase_accurate]

It seems to me that the treble is the difficult part ...

With the right amount of money it is not difficult at all, just expensive.
The one below would achieve what you want with slightly more than 10 Watts.

http://www.stageaccompany.com/ribbon/ribbon.html

Regards

Charles

[SY]

There was an article in Audio Critic a few years back outlining how to put a system like this together. It was based on multi-amping (of course) and JBL drivers.

[paulspencer]

Thanks Charles, have sent them an email to find out how much. I'm expecting them to be pricey ...

[phase_accurate]

In Europe they are around Euro 570.- (a piece) !!

Regards

Charles

[kan3]

A nice 1" compression driver with a good lens on it will have no problem doing what you want...but...only to about 16-17khz - most will drop off after that.