full range without filtres - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Full Range

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 8th December 2005, 11:29 AM   #11
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
True enough gentlemen. However, we can only work within the guidelines stipulated, and though we can advise...
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 8th December 2005, 12:05 PM   #12
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by Yury
thank you gentlemen!
yes, I'm sure . passive filters realy introduce distortion. freqency and phase. and I'm just want to make system without it.
This may be relevant to crossovers but the corrollary of that
is passive filters implementing BSD and response correction
reduce frequency and phase distortion.

/sreten.
  Reply With Quote
Old 9th December 2005, 05:15 AM   #13
diyAudio Member
 
Artmaster's Avatar
 
Join Date: May 2004
Location: Kiev
Blog Entries: 1
Send a message via ICQ to Artmaster Send a message via MSN to Artmaster
Quote:
What causes the distortion, where does it come from? The passive components themselves cause distortion? How and why? What does the distortion sound like?
gday! no, I mean distortion induced flow separation by filtres.
I won't separate voice range. it should be from one sourse.
it's just my opinion, not more.
I have active sub and want to use it as lowrange part of these loudspeaker. let's it add heart, interior for system from 30Hz to 80 Hz. but other sound wave band I want to get from one sourse and plan to use 2 pcs 8" driver for it.
that's why I ask all of you about Fostex.
should it work together I hope it will be better, couse they have to equilibrate individual distortion, system take range of power as overload characteristics and it'll has more linear gain-frequency respons.
sealed box has the best impact characteristics. variovent just like sealed, but allow to make box smaler. that's why I want to use it.
__________________
Artmaster live in www.artmaydan.org.ua
  Reply With Quote
Old 9th December 2005, 09:27 AM   #14
rentzu is offline rentzu  Jamaica
diyAudio Member
 
Join Date: Dec 2005
Location: independent republic of los angeles.
Send a message via AIM to rentzu Send a message via MSN to rentzu Send a message via Yahoo to rentzu
mr elliot agrees with him...

http://sound.westhost.com/biamp-vs-passive.htm#3.0

from what i get, with passive xover networks in the output circuit, you block the electromotive feedback (from the speaker drivers momentum) back into the amp outputs unequally, introducing an unbalanced load on the +/- outputs.

how does that not affect anything?

better amps will have very low output impedance, making this voltage source somewhat significant.

or no?
  Reply With Quote
Old 9th December 2005, 10:15 AM   #15
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
I'm not sure I agree with the notion that 'better amps will have a lower output impedence.' Well, yes, in some cases, but not all. What is 'better' depends on the application you intend to use it with.

Active = better as a general rule of course, of course. Very few would deny that. In terms of filtering, active DSP will allow you to compensate for aberations in the driver's frequency response up and down, which a passive filter cannot do effectively, and also keep the driver's efficiency high.

Sorry, but I still don't see how you can possibly hope to achieve this. I've had a go in Martin's MathCad sheets (not that I really needed to to confirm this), and you're trying to achieve the impossible -you can't contravene the laws of physics you know.

You want a box enclosure for the full-range units. Fine, no worries there in itself. But it's the combination of factors you want that's the problem. Let's use the FE206E as an example shall we.

OK, the recommended vented enclosure for this driver is 45L, and it's F3, which, like all vented enclosures, is very steep, is in reality around 75Hz. A sealed enclosure for this driver would need to be much larger for it to get even close to this. A variovent will fall somewhere between the two sizes. Let me re-iterate: a variovent enclosure will need to be LARGER, not smaller, than a vented box using the same driver. Call it 60L (and that's being very optimistic) There's nothing fancy about variovents; it's just aperiodic -a leaky, sealed box in other words. But you want to use a smaller box than the recommended enclosure. You can do it, but it will roll-off much higher -far higher than you want to cross your subs over.

It gets worse. You want to put 2, not 1 drivers into this enclosure, which is already in practical terms too small for just one 8" full-range unit to get down to the level you need. Those drivers will cut off very high indeed, and there will also probably be a massive peak (+10 or so decibels) when they do. And you can't compensate for this, because you refuse to use any filters. I'd expect this cut-off to occur at around 150Hz (at the very lowest), so you're going to get a giant hole in the frequency response between 80Hz, which is the upper limit of the range you want to run your subs, and the lower limit of the full-range drivers in the enclosure you wish to put them in.

OK, next problem. Assuming you've invented a new form of physics which will allow you to stuff those two drivers into an enclosure which is actually too small for just one of them and get them to go low enough to cross over smoothly to your subs, you'll have to go bipolar with these full-range units, unless you roll one of them off (which you can't do because you don't want any filters). If you don't go bipolar, on top of the major issues I've just described, you'll run into severe lobing problems because, even if you mount the full-range units with their surrounds touching each other, the physical size of the 8" driver-cones keeps the centres of the drivers, which produce the higher frequencies, too far apart. The result will be a very ragged response curve above 1KHz, and this will get progressively worse the higher you go.

So, bipolar is your only option in this respect. As it happens, that's usually a good way forward anyway, particularly in your case, because as you refuse to use any filters, if you just mounted the drivers on the front baffle, you'll run into severe baffle-step diffraction issues.

I don't want to seem down, and believe me I'm not intending criticism here (not my way -I like to help and encourage everyone as much as I can, if I can in our hobby), but I honestly believe you might have to have a rethink of your intended approach. It will reap rewards in the long term.

If I might ask some questions? We might be able to come up with some workable solutions, trying to keep your size and other requirements in mind.

1) What sort of music do you listen to?
2) How large is your room and what shape?
3) Where are you intending to put the speakers?
4) How loud do you like to listen?

Regards
Scott
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 9th December 2005, 11:39 AM   #16
MJK is offline MJK  United States
Account disabled at member's request
 
Join Date: Feb 2002
Location: Clifton Park, NY
Scott,

You have already put a lot more time into this discussion then I have and your points are well stated, I don't have anything else to add.

I have looked at the reference provided above and still do not see how the distortion conclusions have been reached, so I am going to bow out. My take on the reference is a little bit different. I am not following the logic above and must have missed something.

Did you try the newer version of the worksheet I sent, did it run on any of the PC's you tried?
  Reply With Quote
Old 9th December 2005, 12:35 PM   #17
sreten is offline sreten  United Kingdom
diyAudio Member
 
Join Date: Nov 2003
Location: Brighton UK
Quote:
Originally posted by Scottmoose

Let me re-iterate: a variovent enclosure will need to be LARGER, not smaller, than a vented box using the same driver. Scott
I'm sure he meant to say sealed box, in that case the above is true.

/sreten.
  Reply With Quote
Old 9th December 2005, 01:50 PM   #18
diyAudio Member
 
Scottmoose's Avatar
 
Join Date: Mar 2005
Location: UK
That was my assumtion too.
__________________
Community site www.frugal-horn.com Commercial site www.wodendesign.com
  Reply With Quote
Old 9th December 2005, 06:56 PM   #19
scottw is offline scottw  United States
diyAudio Member
 
Join Date: Feb 2004
Location: Kalifornia
Yury, you may want to have a look at this speaker built by Omega. Uses a Visaton B200 driver run fullrange in an aperiodic box with two vents:

http://www.redwineaudio.com/Omega_B200_Aperiodic.html

The drivers are probably available in your area. The B200 has a rising response but most report that once broken in the rise is less obvious. Some are running this driver on open baffles(dipole) because of its qt of ~.7.

Also, the previous posters to this thread know way more than I about designing speakers.
__________________
"The Adobe Updater must update itself before it can check for updates. Would you like to update the Adobe Updater now?"
-Adobe Updater
  Reply With Quote
Old 9th December 2005, 07:32 PM   #20
Speakerholic
diyAudio Moderator
 
Cal Weldon's Avatar
 
Join Date: Jan 2004
Location: Near Vancouver
ScottW,
Do you mean:
doo wah ditty ditty dum ditty doo?

It means: She looks good, looks good, she looks fine, looks fine
__________________
Next stop: Margaritaville
Some of Cal's stuff | Cal Weldon Consulting
  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


Similar Threads
Thread Thread Starter Forum Replies Last Post
Frequency range of the human voice & full range center channel speakers jwmbro Multi-Way 31 20th January 2008 03:07 PM
5.25 full range boxcustom Full Range 0 20th March 2007 09:33 PM


New To Site? Need Help?

All times are GMT. The time now is 07:25 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