I believe it is the spider resonance. It is usually around 400 - 500Hz for this kind of driver. The 15BG100 has a double silicon spider which is well damped.
Indeed!
I wanted to change "surround" to "suspension", but I was too late
In order to avoid any misunderstanding, I think the 18Sound NLW series are excellent woofers, just like the B&C NBX/SW/TBX series.
I might even try one of those in my own system some day.
BUT, It should be clear to everyone, such 'heavy duty' woofers are power hungry beasts and definitely NOT not the best match for low power amplifiers.
While others may disagree, these woofers do need a certain level to 'fully open up', because that's what they are designed for > Very high SPL for hours on end in harsh environments without thermal and mechanical failures.
I wanted to change "surround" to "suspension", but I was too late
In order to avoid any misunderstanding, I think the 18Sound NLW series are excellent woofers, just like the B&C NBX/SW/TBX series.
I might even try one of those in my own system some day.
BUT, It should be clear to everyone, such 'heavy duty' woofers are power hungry beasts and definitely NOT not the best match for low power amplifiers.
While others may disagree, these woofers do need a certain level to 'fully open up', because that's what they are designed for > Very high SPL for hours on end in harsh environments without thermal and mechanical failures.
This thread somehow reminds me of what we call "Hornberger Shooting" in Germany
And I doubt that the TO with its chosen horn can live up to its own claim, which he has defined at the beginning of this thread. The big long and round horn will beam too much and in the end he will not be able to get around a 3-way system which has it's own challenges.
And I doubt that the TO with its chosen horn can live up to its own claim, which he has defined at the beginning of this thread. The big long and round horn will beam too much and in the end he will not be able to get around a 3-way system which has it's own challenges.
Was searching to read more about these Dayton h812 horn I’m listening to at the moment. Believe they are same as the paudio ph-3220 and monacor mrh-200. Cheap exponential flair.
Found this nice and clean 2-way design called the ‘Statement’ - HiFi-compatible PA loudspeaker. Uses the Monacor SPA-115PA woofer. Specs look good?
Statement
MONACOR SPA-115PA - 15" Woofer
Found this nice and clean 2-way design called the ‘Statement’ - HiFi-compatible PA loudspeaker. Uses the Monacor SPA-115PA woofer. Specs look good?
Statement
MONACOR SPA-115PA - 15" Woofer
Hi everybody! I have pairs of GPA/Altec 414-8c 12" woofers and Altec 902 CDs. I have been thinking about building a speaker "inspired by" the Gedlee Abbey.(I realize that they won't sound the same.) I will be using subwoofers. I have 3 different horns that will mate with the 902s: Bruce Edgar 650 hz round wood tractrix horns, Dayton H6512s, and B-52s from Parts Express. I am also open to buying more horns; compared to the drivers they are relatively cheap. My question is this: I was going to build boxes approximately the same size as the Abbey, about 26" by 15". But based upon reading this thread perhaps I should be looking to build wider boxes, 20" or more. Is there an advantage to a wider front baffle? Is there a point of diminishing returns? And if anyone wants to suggest a different horn, that would be great.
Could you say why you are still trying to talk with unskilled people, are you a little masochist? a technical evangelist should talk with professionals, no?
If you want the speaker to be "inspired by Gedlee" then you will want to use the H6512 or B-52 QSX clone. Both are CD waveguides. I would start by testing the Altec CDs on both horns to see which works best. Remember, CD waveguides have have falling response (6dB Octave) that will need to be compensated for in the crossover. This is not a negative, but a requirement for a true CD waveguide. If you want to be even more true to the inspiration, you could use an axis-symmetric OBS waveguide (Autotech). The advantage of wider boxes is to reduce the necessity for baffle step frequency compensation. The BSC can be done in the crossover.
I wonder myself, a stunning comment. People with decades of professional experience should be prepared to be greeted with hostility when they simply want to share their insights.
Sharing insights is ok and i appreciate it. Insisting that you are right about everything you say without checking is something else entirely.
About geniuses that are deeper in audio (designing their drivers from scratch and cabinets around them) here is an interview with one.
YouTube
He explains at a certain point a difference in sound he perceived that was a product of a stronger motor to lighter moving mechanism. Of course he reworked it in next iteration. Not directly correlated with this subject but close enough to see that there is always something that you could miss or did not know how to calculate yet. Geddes himself wrote he doesn't do low level signal measurements but uses rather high level. I wrote without checking so allow me to quote from our clash five years back:
This post explained to me why there could be the differences and indirectly turned my head in direction of Kef concentric loudspeakers.
In my response to him:
About geniuses that are deeper in audio (designing their drivers from scratch and cabinets around them) here is an interview with one.
YouTube
He explains at a certain point a difference in sound he perceived that was a product of a stronger motor to lighter moving mechanism. Of course he reworked it in next iteration. Not directly correlated with this subject but close enough to see that there is always something that you could miss or did not know how to calculate yet. Geddes himself wrote he doesn't do low level signal measurements but uses rather high level. I wrote without checking so allow me to quote from our clash five years back:
This post explained to me why there could be the differences and indirectly turned my head in direction of Kef concentric loudspeakers.
In my response to him:
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I also find it amazing how quickly people on DiyAudio dismiss the wisdom of industry professionals who have done the hard yards and learnt from their mistakes. In the process these professionals get sick of all the bickering and leave the forum, a great loss to everyone who enjoys learning from the them.
That would not be necessary as long as the debate doesn't degenerate into a personal vendetta.
This being said, I guess we all hope and expect one minor hiccup doesn't keep Dr. Geddes from posting in this thread.
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Gift Horse
Earl,
They do not appreciate the nobility of the contributions you make here. Acoustics has a steep learning curve, due to the mastery of a multiplicity of disciplines required to become a successful practitioner of it. There is a difference in commitment between that of a hobbyist, and that of a professional. It is patently clear from many of the negative comments made here, that the friendship between arrogance and stupidity remains alive and well . For many of us, your efforts are meaningful and significant to improving our understanding of the subjects discussed here. We hope that you continue this philanthropic practice. Thanks Earl.
Regards,
Bill
Earl,
They do not appreciate the nobility of the contributions you make here. Acoustics has a steep learning curve, due to the mastery of a multiplicity of disciplines required to become a successful practitioner of it. There is a difference in commitment between that of a hobbyist, and that of a professional. It is patently clear from many of the negative comments made here, that the friendship between arrogance and stupidity remains alive and well . For many of us, your efforts are meaningful and significant to improving our understanding of the subjects discussed here. We hope that you continue this philanthropic practice. Thanks Earl.
Regards,
Bill
This is the thread Zvu referred to.
Apart from a few differences of opinion there's no 'clash' to speak of.
At some point, Zvu and Dr. Geddes actually reach a kind of consensus.
There's at least one notable comment by Dr. Geddes, concerning rubber roll surrounds (that I fully agree with):
"Rubber is to low damping. From what I have found only multiple role fabric surrounds with high damping impregnation will have a HF response that is smooth. This makes perfect sense because this type of surround will absorb outgoing waves in the cone body and not reflect them. A wave has to reflect to cause a cone resonance - no reflection, no resonance - no resonance, smooth response."
The vast majority of the forum members as well as the audio community in general, greatly appreciate Dr. Geddes' contributions.
Apart from a few differences of opinion there's no 'clash' to speak of.
At some point, Zvu and Dr. Geddes actually reach a kind of consensus.
There's at least one notable comment by Dr. Geddes, concerning rubber roll surrounds (that I fully agree with):
"Rubber is to low damping. From what I have found only multiple role fabric surrounds with high damping impregnation will have a HF response that is smooth. This makes perfect sense because this type of surround will absorb outgoing waves in the cone body and not reflect them. A wave has to reflect to cause a cone resonance - no reflection, no resonance - no resonance, smooth response."
The vast majority of the forum members as well as the audio community in general, greatly appreciate Dr. Geddes' contributions.
I quoted the posts in a manner that everyone can go an read so they don't miss the context - and preferably don't jump to conclusions.
My bad choice of words?
'Clash' has colloquial meaning in my city. Everything that is opposing to anything else. I don't know what "personal vendeta" you are referring to. In what post have i ever told anything on personal basis (to anyone)? Five years ago is probably the last time i had any contact with Earl. I don't understand all this fuss you guys are making.When so many of you write hickup, disrespect or something else for that matter, i would kindly ask of you to point to the guy and part of the post where that is evident. This way you are making a different opinion and point of view 'a clear case of disrespect'.
Cheers
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