Beyond the Ariel - Page 895 - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 5th June 2013, 11:12 PM   #8941
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by badman View Post
Not really an issue here- the panel's not that thick and the driver beamwidth is surely very narrow by any freq it'd be an issue at.

Of course, I'd prefer if it were mounted against a beveled or rounded edge.
About 1.7 kHz is where diffraction will show itself with respect to the fullrange, if suppressed a bit in level when compared to the average because of directivity. Below 1.4 kHz it's sure to be an issue.

The tweeter also has a diffraction issue, though perhaps it's high enough in freq. that it's perceptually inconsequential.


The transitions on each, because of the "ripple" of the baffle structure, protrudes enough to be nearly 90 degrees, or a "hard" angle - particularly at horizontal positions.

Considering the dispersion of the whizzer for the fullrange portion - there will also be a *reflection*.


Basically the design itself, though structured for isolation of the drivers with respect to the box, has some problems that could have been at least mitigated but weren't. (..which sadly seems "par for the course" in many commercial offerings irrespective of price. )


I couldn't say if any of it would be audible or not.. For that kind of money though none of those design problems should be there ..or perhaps the emphasis is on sculptural art rather than audio?
__________________
perspective is everything

Last edited by ScottG; 5th June 2013 at 11:24 PM.
  Reply With Quote
Old 6th June 2013, 04:22 AM   #8942
diyAudio Member
 
thoglette's Avatar
 
Join Date: Dec 2008
Quote:
Originally Posted by Elias View Post
Faitalpro 10FE200 Rms 0.75 less than 50
Qts=0.7 so open baffles only.
  Reply With Quote
Old 6th June 2013, 05:30 AM   #8943
diyAudio Member
 
Gary P's Avatar
 
Join Date: Apr 2002
Location: Portland OR
Another contender in the high Qms and low Rms is the Seleneium 12PW5.

Rms .8
Qms 16.33

$90.00 at Parts-Express

Only thing that does not look good is the dip at ~450Hz.
__________________
http://www.pimmlabs.com/
  Reply With Quote
Old 6th June 2013, 05:36 AM   #8944
diyAudio Member
 
picowallspeaker's Avatar
 
Join Date: Apr 2007
Usually the dip is given by the IEC baffle the driver is attached when measuring
  Reply With Quote
Old 6th June 2013, 05:53 AM   #8945
ScottG is offline ScottG  United States
diyAudio Member
 
Join Date: Feb 2003
Location: US
Quote:
Originally Posted by Gary P View Post
Another contender in the high Qms and low Rms is the Seleneium 12PW5.

Rms .8
Qms 16.33

$90.00 at Parts-Express

Only thing that does not look good is the dip at ~450Hz.
..and similarly (as a 15"):

http://www.parts-express.com/pedocs/...ifications.pdf

-for $110.
__________________
perspective is everything
  Reply With Quote
Old 6th June 2013, 12:01 PM   #8946
Pano is offline Pano  United States
diyAudio Moderator
 
Pano's Avatar
 
Join Date: Oct 2004
Location: Kona, Hawaii
Blog Entries: 4
I have a pair of the Selenium 15". Good drivers. I used them on Open Baffle.
  Reply With Quote
Old 7th June 2013, 01:54 AM   #8947
diyAudio Member
 
LineSource's Avatar
 
Join Date: Sep 2003
Location: SiliconValley
Quote:
Originally Posted by Elias View Post
Faitalpro 10FE200 Rms 0.75 less than 50
The Faital 10FE200 models -3db ~70Hz in a sealed 1.8 - 2 cu ft enclosure, and looks like a good candidate for a 3-way midbass with other low cost speakers like the $35 SEOS15 waveguide + $65 DNA360 + $125 Pyle PDW18125.

A 90 x 40 SEOS waveguide allows a corner placement option.

Controlled directivity now often means delivering a wide enough sweet spot for a family on a couch watching an on-wall flat panel. Advertisements with a single guy in one chair with a flapping scarf have been replaced by home theater glitz.
Attached Images
File Type: jpg Poor Man.jpg (96.2 KB, 517 views)
File Type: jpg FamilyAudio.jpg (130.3 KB, 512 views)
File Type: jpg Crazy Tweeters.jpg (84.5 KB, 467 views)
  Reply With Quote
Old 7th June 2013, 02:12 AM   #8948
diyAudio Member
 
Join Date: Jan 2011
Location: Willamette Valley
I'm a family man. It's the best.
Glitz not so much in the long run, which is what family is
  Reply With Quote
Old 7th June 2013, 02:55 AM   #8949
diyAudio Member
 
Join Date: May 2010
Location: MN
Quote:
Originally Posted by Gary P View Post
Another contender in the high Qms and low Rms is the Seleneium 12PW5.
Rms .8
Qms 16.33
$90.00 at Parts-Express
Only thing that does not look good is the dip at ~450Hz.
Quote:
Originally Posted by picowallspeaker View Post
Usually the dip is given by the IEC baffle the driver is attached when measuring
But the free air impedance phase graph looks like it's got issues to match the response, no? It's got blips around 120Hz, 375Hz, and everywhere above 1k.
  Reply With Quote
Old 7th June 2013, 08:42 AM   #8950
diyAudio Member
 
Lynn Olson's Avatar
 
Join Date: Jul 2004
Location: Northern Colorado
I've spent a fair amount of time auditioning the AH425 and other LeCleac'h Azurahorns. Subjectively, not much happens off-axis ... there's no sudden change, the sound just loses a bit of focus ... it's quite not as sharp and crisp. But it's a fairly small change compared to most other horns I've auditioned, which can sound very different as you walk around the room (for example, when you walk out of the beam of a conical horn).

Subjectively, it sounded best slightly off-axis, with about half of the throat of the compression driver visible from the listening position. By measurement, there's not much change over a 10-degree span, and no on-axis suckout or other weirdness to deal with. As get further off-axis, it just rolls off earlier, with no sudden change, and this continues even when you get way, way off-axis, like 90 degrees, or even behind the loudspeaker. It basically acts like a fairly big dome tweeter in terms of directivity, not like a horn at all.

I usually "voice" speakers using pink-noise, aiming for natural sound at all possible listening positions, and going to some trouble to avoid obvious whistling phasey sounds when well off-axis. This is where conicals and exponentials can be troublesome: if EQ'ed for good behavior over a frontal 45-degree sweep, they can get pretty weird at 60, 90, and 120 degrees off-axis, with very strange impulse and frequency response. The LeCleac'h T=0.707 just rolls off, with no deep nulls or peaks when far off-axis.

Part of the reason I take this approach is consideration of the first several reflections that arrive at the listening position. They're not hard to work out: the first will be the floor bounce, which arrives between 2.5 to 3 mSec after the direct sound, and is only very slightly attenuated (1 dB or less) by carpeting. The next will probably be the ceiling reflection (unless it's a 10-foot or higher ceiling), arriving 3 to 5 mSec after the direct sound.

The next several reflections depend on the location of the speaker in the room. If the speaker is reasonably well away from the sidewalls (highly recommended), the next reflection will be from behind the speaker. The timing of this depends on the depth of the speaker and the distance to the rear wall. These are large speakers, which will probably be 6 to 12 inches away from the rear wall, so the rear-wall reflection will be delayed by about 5 to 6 mSec or so. (1 millisecond is fairly close to 14 inches.)

The (nearest) side wall reflection will obviously depend on the distance from the side wall. Placing the speaker closer than 1 to 2 feet away from the side wall will degrade imaging, regardless of polar pattern, partially because the bass below 500 Hz is nearly omnidirectional, regardless of fancy techniques used for the HF section.

(Full-range dipoles are a special case, but even dipoles don't do well in corners. Bass horns retain pattern control at lower frequencies, but a bass horn that is pattern-controlled down to 100 Hz is starting to get too large for domestic applications.)

So it's not a mystery where the first reflections will come from. We can work backward from this and work out the emission angle of each reflection: the floor reflection is vertically off-axis by 20 to 30 degrees, the ceiling reflection is vertically off-axis by a little more, and the rear-wall reflection is around 150 to 180 degrees off-axis. The emission angle into the nearest side wall will be around 90 degrees off-axis (if the speakers are aimed at the listener).

Rotating the speakers will have a strong effect on the emission angle going into the side walls, as well as affecting the emission angle for the first-arrival sound. Speaker rotation (toe-in) alters the level and spectral balance of the side wall reflection versus the direct-arrival sound. Most speakers are not optimized for smooth response 90 degrees off-axis, so this can be a rather critical adjustment for the consumer.

Note that nearly all of the reflections in the first 6 to 8 mSec are far off-axis, and do not fall in the traditional elliptical 45 to 60-degree "sweet spot". If the response from the floor, ceiling, rear, or side wall is peaky (or drastically different than the direct-arrival spectra), yes, it will be audible on pink-noise as you move around the room.

The other thing that can happen is the loudspeaker will be extremely sensitive to small changes in room location and rotation/toe-in, since this alters the phase angle of the first several reflections as they arrive at the listening position. If any of these first reflections has deep nulls or peaking (relative to the direct-arrival spectra), that will create an impression of phasiness on pink-noise or music that has a dense spectra, thanks to comb-filtering between the first-arrival sound and the reflection with an erratic spectra (for example, the reflection off the rear wall).

Last edited by Lynn Olson; 7th June 2013 at 09:09 AM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



New To Site? Need Help?

All times are GMT. The time now is 12:20 PM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2