planet10 said:
At least mine are in English.
You would be whistling a different tune if my results were more to you liking.
Where are the results of your tests? You have access to the same equipment as I do, plus you possess more technical know how (apparently).
Show us how it's done.
have seen many pictures of single driver "horns" sitting in the middle of a tastefully decorated living room, producing next to nothing below 200Hz, and resonating quite happily with large unbraced, undamped (heaven forbid) panels
Then i must rush out to tell everybody that the A126 or the A166 is not getting 50 Hz (A126) or 40 Hz (A166) in room measured response and being quite happy with the room filling bass performance.
Thank you for your reponse. When you understand physics then please post something worthwile instead of assumptions.
ron
Do you have those figures - the resonant frequency of MDF and Baltic birch plywood? How far apart are they?
Yes i do.
Depends on the panel length/width.
Depends on T. and the energy involved
Its dependant on the above.
ron
Then i must rush out to tell everybody that the A126 or the A166 is not getting 50 Hz (A126) or 40 Hz (A166) in room measured response and being quite happy with the room filling bass performance.
Thank you for your reponse. When you understand physics then please post something worthwile instead of assumptions.
ron
Do you have those figures - the resonant frequency of MDF and Baltic birch plywood? How far apart are they?
Yes i do.
Depends on the panel length/width.
Depends on T. and the energy involved
Its dependant on the above.
ron
ronc said:
Now don't take things personally.
You didn't answer the first part of my question: the resonant freq of MDF vs BB?
Response down to 40-50Hz? That good. What does it look like over 200Hz, with the panel resonance contribution?
Considering the size of some of these "horns", it begs the question: " what would the in room response be for a similar sized BR speaker equipped with a woofer"? Better?
MJL21193 said:
Quality or quantity?
<http://forum.audiogon.com/cgi-bin/frr.pl?rspkr&1206374175&read&3&4&>
dave
ronc said:
Equal size panels, equal conditions, test results! Figures? How much of a difference is there between MDF and BB?
planet10 said:
Both Dave. That link? What is it about? Too long for me to read.
Now don't take things personally.
You didn't answer the first part of my question: the resonant freq of MDF vs BB?
Response down to 40-50Hz? That good. What does it look like over 200Hz, with the panel resonance contribution?
Considering the size of some of these "horns", it begs the question: " what would the in room response be for a similar sized BR speaker equipped with a woofer"? Better?
1. I will always do, I Have (in my Job) design for ppLs lives. I am the controlling factor in which you cross a bridge or drive near a pipeline or even take a cruise ship or work on an offshore platform, YES i take it in a serious manner. Audio is no different.
ron
" what would the in room response be for a similar sized BR speaker equipped with a woofer"? Better?
A damn site easier build with greater performance. IMHO a BVR with either a horn or an OB is the best combo.
You didn't answer the first part of my question: the resonant freq of MDF vs BB?
Response down to 40-50Hz? That good. What does it look like over 200Hz, with the panel resonance contribution?
Considering the size of some of these "horns", it begs the question: " what would the in room response be for a similar sized BR speaker equipped with a woofer"? Better?
1. I will always do, I Have (in my Job) design for ppLs lives. I am the controlling factor in which you cross a bridge or drive near a pipeline or even take a cruise ship or work on an offshore platform, YES i take it in a serious manner. Audio is no different.
ron
" what would the in room response be for a similar sized BR speaker equipped with a woofer"? Better?
A damn site easier build with greater performance. IMHO a BVR with either a horn or an OB is the best combo.
I wonder whether differences in MDF differ significantly or not. MDF seem to range from densities of 500+through 700+ (can't remember whether the units were metric or what). Also we don't know how strictly the term MDF is used in different countries.MJL21193 said:
planet10 said:
Sorry, but I studied the CSD's from the site you linked, but I'm not seeing the "1/2" figure you've arrived at. I don't speak Dutch, and I'm having a problem pinning down which of the plots are for 18mm BB, but I think it's "berkenmultiplex"? (I found "spaanderplaat" - this is particleboard) If that's the case, this reinforces my test results showing the resonance is approximately equal (~500Hz), but the BB is more than 5db "louder" than the MDF.
ronc said:
It's all fun and games here, I'm just trying to get some sensible answers. 🙂
There you go, you have every right to your opinion, and I'm not one to say you are wrong. It is your opinion, after all.
MJL21193 said:
It is in the composite i posted (#228) ... the big blue/black peak is at about 1/2 the frequency of the big green/grey peak, but i guess you missed that.
dave
So now I wonder on that site with the tests, what kind of MDF was used. I have seen some different densities, and the lower density ones seem to have much more damping.planet10 said:
I think the discussion about the suitability of MDF as a speaker enclosure material is tending to go in an unfortunate direction.
Whatever material one uses, the design has to be adequate to the application. Whether one uses MDF or plywood or, say, stitch and glue wood/epoxy, or corrugated cardboard, panel vibrations have to be eliminated and diffraction minimized. Each material requires different treatment. If the design is appropriate to the material then the enclosure will behave competently. I think this is close to self evident, isn't it?
Whatever material one uses, the design has to be adequate to the application. Whether one uses MDF or plywood or, say, stitch and glue wood/epoxy, or corrugated cardboard, panel vibrations have to be eliminated and diffraction minimized. Each material requires different treatment. If the design is appropriate to the material then the enclosure will behave competently. I think this is close to self evident, isn't it?
I am not too keen on bracing, at the least in the way its often seen...very often I see it executed in way that it only transfers the energy from one panel to another and maybe even amplifying problems 
MATRIX is the magic word 😎 unfortunately it wont work with horns 😀 but a bit restricted it may be used in BR
MATRIX is the magic word 😎 unfortunately it wont work with horns 😀 but a bit restricted it may be used in BR
graaf said:
Blame Dave 🙂
tinitus said:I am not too keen on bracing, at the least in the way its often seen...very often I see it executed in way that it only transfers the energy from one panel to another and maybe even amplifying problems
MATRIX is the magic word 😎 unfortunately it wont work with horns 😀 but a bit restricted it may be used in BR
A true horn will not need much bracing as it's expanding throat will not yield large flat panel. Curved or segmented panels are inherently self bracing (to some degree).
We don't see many true horns round these parts though...
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