Are three inexpensive subs better than one expensive sub-Dr. Earl Geddes Approach - Page 7 - AVS Forum
Forum Jump: 
 15Likes
Reply
 
Thread Tools
post #181 of 2123 Old 02-26-2009, 08:52 PM - Thread Starter
AVS Special Member
 
Randybes's Avatar
 
Join Date: May 2002
Location: Midwest
Posts: 2,622
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by J_Palmer_Cass View Post

Hey, how about a single chart from you that clearly shows how well your speakers are integrated?

You are making this personal. Let's say mine are horrible, does that make my question irrelevant? You really are being much too defensive. This is not a competition of "my system" against yours. This is a competition of your approach against Dr. Geddes. We have measurements showing seat to seat improvement with Dr. Geddes approach. We don't have your seat to seat variation, it has NOTHING to do with my system. Assume I am listening to a Bose radio and am the biggest idiot in the audio world. All you have to do is show the measurements showing that Randy is the biggest idiot on the internet. That should probably appeal to you.

Just to make things honest, I would be willing to travel to your location to verify.
Randybes is offline  
Sponsored Links
Advertisement
 
post #182 of 2123 Old 02-26-2009, 08:53 PM
Senior Member
 
gedlee's Avatar
 
Join Date: Dec 2008
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 37
Quote:
Originally Posted by J_Palmer_Cass View Post

Take my word for it, I already went through all of these combinations. My bias is based on experience. ... Good looking FR charts can sound "not good"!

OK, fine, then the emphasis is on the subjective. Then read the reviews of my setup. And please post the unbiased reviews showing that a smooth frequency response does not "sound good".

As for "experience", I have a little - 35+ years in audio, two books, dozens of patents, .... In my "experience" its all about the FR measurements since the subjective evaluations have a lot of variance and bias, but the science doesn't lie. Thats the beautiful thing about science, in the end, it never lets you down.

"Take my word for it" - an odd phrase given the circumstances. It's not I thats asking for "proof".

Earl R. Geddes
GedLee
gedlee is offline  
post #183 of 2123 Old 02-26-2009, 09:08 PM
AVS Club Gold
 
craig john's Avatar
 
Join Date: Oct 2003
Location: Lancaster, PA
Posts: 10,377
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked: 357
The thing I don't quite understand about "spatial averaging" is that, if you have a peak of 10 dB at a certain frequency at one "spatial position", but you also have a dip of 10 dB at that same frequency, but at another "spatial position", the "spatial average" of the two positions would zero out the peak and the null and you would not know about, or deal with, either one of them.

Chris Kyriakakis of Audyssey talks about this when explaining why measuring the FR at multiple positions and using simple averaging to combine the responses does not show you the complete picture. The Audyssey EQ program has some (proprietary) algorithms in their software that "group" and "weight" the different measured responses to arrive at the final filter(s).
http://www.audyssey.com/technology/index.html

Dr. Geddes, have you ever used an Audyssey product?

Craig

Lombardi said it:
Perfection is not attainable, but if we chase perfection we can catch excellence."

My System

craig john is offline  
post #184 of 2123 Old 02-26-2009, 09:18 PM - Thread Starter
AVS Special Member
 
Randybes's Avatar
 
Join Date: May 2002
Location: Midwest
Posts: 2,622
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 12
Quote:
Originally Posted by craig john View Post

The thing I don't quite understand about "spatial averaging" is that, if you have a peak of 10 dB at a certain frequency at one "spatial position", but you also have a dip of 10 dB at that same frequency, but at another "spatial position", the "spatial average" of the two positions would zero out the peak and the null and you would not know about, or deal with, either one of them.

Chris Kyriakakis of Audyssey talks about this when explaining why measuring the FR at multiple positions and using simple averaging to combine the responses does not show you the complete picture. The Audyssey EQ program has some (proprietary) algorithms in their software that "group" and "weight" the different measured responses to arrive at the final filter(s).
http://www.audyssey.com/technology/index.html

Dr. Geddes, have you ever used an Audyssey product?

Craig

Not answering for Dr. Geddes but in the HAA level 2 thingie I took and became certified-sure you have to eliminate the effect of nulls in the averaging,but after that the average makes perfect sense. How do you eliminate the nulls? Not sure you do, but first seat position and second as everyone keeps saying mutiple subs. After that it is setup. Does that make sense, or have I had too much bourbon? I guess what I am saying is you CAN"T average nulls and peaks or even wide deviations from seat to seat. The measurement showing how you can use mutiple subs in this set-up can smooth bass is shown. After that isn't the average and what is the statistical term, the deviation from the average the important thing? I am way out of my element now, but I hope I have the concept down.

But I think it was said--get a spatial average, look at seat to seat variation and where are you? In effect, you can't look at "simple averaging" if you haven't got less seat to seat variation to begin with which is back to the whole multiple sub thing. So who still thinks one great sub will do it for anything more than one very rigid seat position (if you can even do it there)?. In the end, I think what you want is the smoothest response with the least seat to seat deviation over a wide area, but what do I know?

FWIW, I think your question is a good one. My reading of Todd Welti's question to Dr. Geddes in the FYI forum was similiar. Although I don't know that I KNOW the answer, my reading of the response was that mutilple subs takes the deviation question pretty much out of the picture? Earl, am I so out of it (I think I picked up the right bourbon:-) ) that you can't even begin to address?

My guess is he has not used an Audyssey product but my guess is neither has Dr. Toole but their answer would be the same. The problem as I see it with Audyssey is it CAN'T eliminate the need for multiple subs (even if you have one great one-which is the title of the thread) and the more the better. Just guessing though. There is also some things dealing with modes, excitement and "cancelation" that I don't think I am qualified to address with regards to the various mutiple sub concepts.

p.s. One thing I have had a hard time not doing since getting Earl's mains (Abbey 12's) is NOT listen to music. I keep revisiting my cds. Because of that my movie watching has suffered. Jeff Beck live at Ronnie Scotts as I write this.
Randybes is offline  
post #185 of 2123 Old 02-26-2009, 09:53 PM
AVS Special Member
 
lalakersfan34's Avatar
 
Join Date: Aug 2007
Location: Arcadia, CA
Posts: 3,340
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Quote:
Originally Posted by gedlee View Post


Sure its not great to have subs all over the place, but you have to get your priorities in order. Do you want the "best" bass or not, because if you do, you better get used to multiple subs. But rememebr that because there are lots of them, they don't have to be extremely large. Mine are about 18 x 16 x 14 for what I call the broad band subs which cover about 50 Hz - 150 Hz. These then overlap the mains, which are simple closed box. I use one Ultra Low Frequency sub that covers 25 Hz - 50 Hz for that lowest octave. At these frequencies only one sub is needed and it matters not at all where it is placed as long as its NOT in the middle of the room (given its size that would never happen.)

Dr. Geddes,

I've very much appreciated your input here and have a quick question. I apologize if you already answered this question somewhere in the thread and I missed it. Here's my question:

Is there a reason you recommend using only one "LF" (<50hz) subwoofer and multiple "broad band" subs (50-150hz) as opposed to multiple low frequency subs? Is this for the sake of cost-effectiveness because broad band subs will be cheaper than low frequency subs and you feel that multiple low frequency subs are simply unnecessary? Or is there an actual acoustic reason to use just a single low frequency subwoofer with numerous subs that cover 50hz and up?

Thanks.

Stephen
lalakersfan34 is offline  
post #186 of 2123 Old 02-26-2009, 10:53 PM
AVS Addicted Member
 
sivadselim's Avatar
 
Join Date: Oct 2004
Location: CO
Posts: 16,085
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 54 Post(s)
Liked: 69
Quote:
Originally Posted by J_Palmer_Cass View Post

I happen to use a similar setup to Geddes............

No you don't. If you can't even move 2 of your 3 subs, it's not similar. Just because you cross your stuff over similarly does not make it similar. The crux of his method is the ability to move all 3 subs, freely, so as to provide the best result.


Quote:
Originally Posted by gedlee View Post

J_Palmer_Class has some good points, he just needs to be more objective, open minded and, of course, polite. When one comes at a situation with their mind made up it is readily apparent. Maybe we can change his mind? Who knows.

Good luck. He can be polite, but you are not going to get him to be objective or open-minded.

"All men are frauds. The only difference between them is that some admit it. I myself deny it."
sivadselim is offline  
post #187 of 2123 Old 02-27-2009, 04:25 AM
AVS Club Gold
 
craig john's Avatar
 
Join Date: Oct 2003
Location: Lancaster, PA
Posts: 10,377
Mentioned: 5 Post(s)
Tagged: 0 Thread(s)
Quoted: 119 Post(s)
Liked: 357
Quote:
Originally Posted by sivadselim View Post

Good luck. He can be polite,...

...or not.

Lombardi said it:
Perfection is not attainable, but if we chase perfection we can catch excellence."

My System

craig john is offline  
post #188 of 2123 Old 02-27-2009, 06:32 AM
Advanced Member
 
simplemath's Avatar
 
Join Date: Jun 2008
Location: canada
Posts: 866
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
I am accepting of the 3 sub movement to basically eq the room with their placement, then to fine tune the subs in this placement for best results. You know what is really strange though. Going through the pictures in the thread show us your subs....I can see having 1 sub at the front beside a main, or wherever you place it, BUT I am so scratching my head over the 50% of the pictures where 2,3,4,even 6 subs are all lined up or stacked at one end of the room.

This placement with multiple subs seems soo wrong to me. More subs yes, but I would think the benifits of multiple smaller subs vs one large $$ one is totally lost if they are all in the (same basic location that the 1 larger$$ one would be)

Is their merit in doing this, or are that many people really wasting their $$$ on all those multi subs placed so horribly wrong.

I'd like to see some improvement in a system that currently has a lineup of 4 subs at the front of the room, to optimum placement of the 4 subs throughout the room. This could give huge buyin, and help out about 50% of the pictures that I viewed in that thread. I just see so much "potential" right now being squwandered with the room acoustics, and placements.
simplemath is offline  
post #189 of 2123 Old 02-27-2009, 06:46 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 102
Quote:
Originally Posted by sivadselim View Post

No you don't. If you can't even move 2 of your 3 subs, it's not similar. Just because you cross your stuff over similarly does not make it similar. The crux of his method is the ability to move all 3 subs, freely, so as to provide the best result.


Good luck. He can be polite, but you are not going to get him to be objective or open-minded.




Hey I am nearly always polite you silly little man!


Just to be clear, I do have 4 identical dedicated subwoofers these days that can be used on that system one way or the other. Ebay is your friend if you know what to look for and can wait for it to show up on the cheap. The question is, where to place them!

If you have never tried to integrate three or four subwoofers, you should watch what you say. There is more to it than meets the eye (or ear)!
J_Palmer_Cass is offline  
post #190 of 2123 Old 02-27-2009, 06:54 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 102
Quote:
Originally Posted by simplemath View Post


You know what is really strange though. Going through the pictures in the thread show us your subs....I can see having 1 sub at the front beside a main, or wherever you place it, BUT I am so scratching my head over the 50% of the pictures where 2,3,4,even 6 subs are all lined up or stacked at one end of the room.

This placement with multiple subs seems soo wrong to me. More subs yes, but I would think the benifits of multiple smaller subs vs one large $$ one is totally lost if they are all in the (same basic location that the 1 larger$$ one would be)


The answer is simple. You co-locate multiple subwoofers to get higher maximum SPL dB output levels. Once you have enough output capability, you stop stacking them.

Have you ever tried to lift / move a larger subwoofer?
J_Palmer_Cass is offline  
post #191 of 2123 Old 02-27-2009, 07:00 AM
Advanced Member
 
simplemath's Avatar
 
Join Date: Jun 2008
Location: canada
Posts: 866
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Quote:
Originally Posted by J_Palmer_Cass View Post

The answer is simple. You co-locate multiple subwoofers to get higher maximum SPL dB output levels. Once you have enough output capability, you stop stacking them.

Have you ever tried to lift / move a larger subwoofer?

heh, i guess that is 1 reason why 3 smaller. vs. 1 large. Forgot about the 150 lbs issue. I wouldn't want to be moving subs either if they were more than 100ish pounds each.
simplemath is offline  
post #192 of 2123 Old 02-27-2009, 07:02 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 102
Quote:
Originally Posted by Randybes View Post


But I think it was said--get a spatial average, look at seat to seat variation and where are you? In effect, you can't look at "simple averaging" if you haven't got less seat to seat variation to begin with which is back to the whole multiple sub thing. So who still thinks one great sub will do it for anything more than one very rigid seat position (if you can even do it there)?. In the end, I think what you want is the smoothest response with the least seat to seat deviation over a wide area, but what do I know?



Sure, but show us the FR charts!
J_Palmer_Cass is offline  
post #193 of 2123 Old 02-27-2009, 07:16 AM
AVS Special Member
 
J_Palmer_Cass's Avatar
 
Join Date: May 2005
Posts: 6,472
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 277 Post(s)
Liked: 102
Quote:
Originally Posted by Randybes View Post

And I would love to see your seat to seat variation-one position would mean little to

HAA
Sencore Academy
Harmon Toole/Welti
Dr. Geddes
Etc

If you have consistency,more power to you. I am not against you, but as they say "show me the money"



Two seats. One seat is about 4 feet closer to the front of the room. The seating is a couch and a loveseat in a typical L layout.


The top curves are the 1/3 octave smoothed curves of the two seats as well as the 1/3 octave smoothed average FR curve (purple).

Middle curve (purple) is the 1/24 octave average of the two FR curves below.

Bottom curves are both seats 1/24 octave no smoothing.



J_Palmer_Cass is offline  
post #194 of 2123 Old 02-27-2009, 07:24 AM
 
goneten's Avatar
 
Join Date: Dec 2002
Location: South Africa
Posts: 3,681
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Dr Geddes,

If priority is to achieve smoothest bass at the listening positon, would you advocate the use of setting main speakers to "large" to handle the full low frequency spectrum for each channel in conjunction to using multiple LF subwoofers even if the positions are sub-optimal for that purpose ?

Now let me ask a different question. Would you recommend your method if speakers were ported ? What about content in the main channels that your speakers won't or can't voice ? Some here on this forum redirect bass from each main channel to more than one subwoofer in addition to the LFE track in the attempts to reproduce as much LF content as is possible.

Putting it another way, what is the major disadvantage to using multiple subwoofers with high-passed main speakers that are capable of low frequency extension to within an octave below the crossover point ? Sorry for asking all these questions but I would be interested to hear your views on this.

Thanks.

Regards,
goneten is offline  
post #195 of 2123 Old 02-27-2009, 07:38 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:


Sorry, but you sound like the amateur audio hobbyist that you are. Not that there is anything wrong with being an amateur audio hobbyist. That's what most of us are. Some of us DO know when to shut up and listen (yes, believe it or not, I DO know when to shut up). Some don't.


No worries...I do not get paid to preach audio


I have been asking for measurements and Im sticking to the point that his "Cheap Subwoofers" will work is false.

Other then that he has not posted anything I did not already know. Heck I have read stuff from him and Harmon already. We do have Geddes theories throughout DIY already (Waveguide stuff, etc) so I have listened a long time before you guys have

I will contest that cheap multiple subs are no where as good as quality multiple subs. I have agreed several times with his principles on Mutiple subs and I have already have a similar setup to what he is talking about because its just common sense and it works for me.

Miles, I did expect you to reply to my rant


As for the thread...so far its more of a "Im a PhD with 30 years of audio experience so Im just right" then it is an research thread with scientific proof and measurements.

Again, Geddes has done great things and taught people many things elsewhere but so far but I do not understand why he is jumping down that subjective debate path here and has yet to post any science....he is a PhD afterall

In the end, Im waiting for that all important....here is my site and the products I sell

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #196 of 2123 Old 02-27-2009, 07:55 AM
Senior Member
 
loopguru's Avatar
 
Join Date: Jul 2008
Location: Austin, TX
Posts: 405
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
It seems like a large portion of this question has been asked and answered a few times already in this thread. Run mains large. Plug ports. Overlap, tune..

Quote:
Originally Posted by goneten View Post

Dr Geddes,

If priority is to achieve smoothest bass at the listening positon, would you advocate the use of setting main speakers to "large" to handle the full low frequency spectrum for each channel in conjunction to using multiple LF subwoofers even if the positions are sub-optimal for that purpose ?

Now let me ask a different question. Would you recommend your method if speakers were ported ? What about content in the main channels that your speakers won't or can't voice ? Some here on this forum redirect bass from each main channel to more than one subwoofer in addition to the LFE track in the attempts to reproduce as much LF content as is possible.

Putting it another way, what is the major disadvantage to using multiple subwoofers with high-passed main speakers that are capable of low frequency extension to within an octave below the crossover point ? Sorry for asking all these questions but I would be interested to hear your views on this.

Thanks.

Regards,

loopguru is offline  
post #197 of 2123 Old 02-27-2009, 08:02 AM
Advanced Member
 
simplemath's Avatar
 
Join Date: Jun 2008
Location: canada
Posts: 866
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 11
Hey Penn, it almost seems like a bakyard hack pretending to be Dr. G for some ceredibility, while they sell the goods later. Or give a kickback for the name use, tied to the marketing, but on your own to market the avs site.

edit. bit too over the top.
simplemath is offline  
post #198 of 2123 Old 02-27-2009, 08:02 AM
Senior Member
 
gedlee's Avatar
 
Join Date: Dec 2008
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 37
Randy

The issue with averaging is complex. As I worked out the math from Todds question I found that it wasn't so obvious. As a result, I have decided to keep the details of my analysis confidential for the time being. But here is the situation. No matter how you setup multiple subs, if they are spaced arround the room then they have to - in a statistical sense - lower BOTH the spatial and the spectral variance. This can be and has been shown by numerous qauthors, myself included. It turns out that there is some effect from pacement, but this is less than the effect from just the number. But in my experince placement is not usually completely optional. In other words the room will almost always dictate some placement restrictions. But as a rule of thumb, I find that one sub should be near or in a corner and the next one as far away as possible. The third one usually ends up wher it fits. OK, so far, number of subs most important, placement next in line and then finally you have the ability to set each sub up differently. This can have about the same level of effect as the location. How this last step is done is completely wide open and there are a myriad of opinions out there about it. I personally believe that in the end almost all of these techniques will boil down to just about the same thing. Todd uses a mass of measurement data and a mass of calculations to arrive at complex fitting functions which are then reduced to a "best fit" on the available parameters. I average at the get-go to reduce the data set and then "best-fit" to this reduced set. Will these two end up at the same point. Exactly probably not, but very close is very likely. So the question that is unanswered is what is the best way to setup multiple subs once you have the number and locations selected. There is no concrete answer to this at the moment.

If the mains have LF capability, then they should be considered as another source for the LF response - the more the better. SO leave them as "large" and don't HP them, is my recommendation. If you do this, then it shouls be obviuos that there is no advantage to a "ported" design and the mains should then be closed box.

The issue with my usage of ULF and BB subs is more complicated. Its based on "practical" not on some ideal. Ideal would be three subs that handled 20 - 200 Hz. But this is not "practical" so I split this decade into a pair closer to "octaves". The reason is that bandpass deisgns are very efficient but only over a small bandwidth. The one thing about room response at LF that I feel gets missed in these discussions is how the response varies arround the room at LF. At near DC there is NO variation of the response arround the room, it is everywhere the same. As the frequency goes up it gets greater and greater. But a sub operating from 25-50 Hz will se virtually NO spatial variation in either its response at the seating location or its sensitivity to location. Usuing more than one will thus only increase the output, but do little to nothing to smooth the response as there basically is nothing to smooth. generally ain this frequency range there will be a singular LF mode that is usually not very damped because damping is not very effective in this range. This is exactly where EQ works the best - the first few modes. My room has a mode at 40 Hz that no amount of sub control or placement can alleviate - only an EQ band can bring it under control. Thus (in my room) the single ULF sub is very efficient in the 25-50 Hz band and only one is necessary. Abouve about 50 Hz, more and more modes are evident and this is where the room response benifits from multiple subs - of which the mains are also sources in this region. Proper setup does make the region from about 50 Hz -150 Hz both spatially smooth and spectrally smooth. This is exactly the range covered by my BB bandpass subs. This approach WILL NOT work in all situation, but has worked in any room that I designed. At LF the room dominates the situation and every room is different. There is no one right answer in detail, but any succesful approach has to start with multiple subs placed arround the room (not stacked as this is really only a single sub). The size, bandwidth, power to these subs will be specific to the room.

Earl R. Geddes
GedLee
gedlee is offline  
post #199 of 2123 Old 02-27-2009, 08:06 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:
Hey Penn, it almost seems like a bakyard hack pretending to be Dr. G for some ceredibility, while they sell the goods later. Or give a kickback for the name use, tied to the marketing, but on your own to market the avs site.

Conspiracy, not really. Joined avs in Dec. Opened business around the same time. AVS is the target audience, first mistake, and I really doubt Dr. G is leading this campaign....the partner likely approached Dr. G with visions of grand $$$. Lets see the price list allready.

Geddes has lots of great info and he has credibility. I just want to make that clear I have followed some of his stuff and I really would love to get his speakers (Abbeys) in my house at some point if I ever stop buy drivers myself and playing around being a "amateur audio hobbyist"

I just dont believe that "cheap subs" part of this whole discussion. Lets go buy 4 BIC subs and be happy then

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #200 of 2123 Old 02-27-2009, 08:08 AM
otk
AVS Special Member
 
otk's Avatar
 
Join Date: Jul 2006
Posts: 7,496
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Quote:
Originally Posted by Randybes View Post

Exactly what I want to get started. Some opinions and some replys from Dr. Geddes. Hopefully, Todd from Harmon will also participate. Mark Seaton and others, lets get a good debate going (civil please). Full disclosure, I heard Dr. Geddes approach and I have 2 J&L f113's, SVS Ultra 13 and some others. His room was the best I have ever heard.

is this guy lying also ?

Join Date: May 2002
Location: Midwest
Posts: 2,515

All this noise about noise.
♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫
Finding the acoustic sweet spot.
otk is offline  
post #201 of 2123 Old 02-27-2009, 08:09 AM
Senior Member
 
gedlee's Avatar
 
Join Date: Dec 2008
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 37
Quote:
Originally Posted by penngray View Post

Again, Geddes has done great things and taught people many things elsewhere but so far but I do not understand why he is jumping down that subjective debate path here and has yet to post any science....he is a PhD afterall

I could easily loose you in math in a line or two - what point would that make? My entire approach is based in science, and I have used science many times in this thread alone but when I quote it or use math people get lost. The science is out there where it should be in journals and textbooks. THIS is not the place for a mathematical discussion on the statistical properties of the LF sound field in small rooms.


Quote:
Originally Posted by penngray View Post

In the end, Im waiting for that all important....here is my site and the products I sell

This comment is rude. I was asked to come here and if I am not wanted I will go away.

Earl R. Geddes
GedLee
gedlee is offline  
post #202 of 2123 Old 02-27-2009, 08:14 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:
I could easily loose you in math in a line or two - what point would that make? My entire approach is based in science, and I have used science many times in this thread alone but when I quote it or use math people get lost. The science is out there where it should be in journals and textbooks. THIS is not the place for a mathematical discussion on the statistical properties of the LF sound field in small rooms.

Of course you would

I would have to brush of my Applied Mathematics (Electrical Engineering minor) degree from University of Waterloo, Canada that I obtained over 20 Years ago....I can not remember much though, spent the last 20 years running a small software company instead but you have the PhD....we already know that

Quote:
This comment is rude. I was asked to come here and if I am not wanted I will go away.

lol, are you a serious person 24/7? Just post the measurements of your room with those "very cheap" subs and I will stop making jokes.

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #203 of 2123 Old 02-27-2009, 08:14 AM
Senior Member
 
gedlee's Avatar
 
Join Date: Dec 2008
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 37
Quote:
Originally Posted by penngray View Post

I just dont believe that "cheap subs" part of this whole discussion. Lets go buy 4 BIC subs and be happy then

I addressed this. I never said "junk" so don't put words in my mouth. "Cheap" to me only means inexpensive not disfunctional. The B&C drivers that I use are "cheap"? Your not quoting my views in context. The point is that multiple subs will outperform one mega-buck subs when equal expense is made. I did use a cheap $100 sub for awhile and there was an improvement going to the more expensive B&C, but it wasn't night and day like multiple versus singular subs.

Earl R. Geddes
GedLee
gedlee is offline  
post #204 of 2123 Old 02-27-2009, 08:19 AM
Senior Member
 
gedlee's Avatar
 
Join Date: Dec 2008
Posts: 350
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 13 Post(s)
Liked: 37
Quote:
Originally Posted by simplemath View Post

Hey Penn, it almost seems like a bakyard hack pretending to be Dr. G for some ceredibility, while they sell the goods later. Or give a kickback for the name use, tied to the marketing, but on your own to market the avs site.

Conspiracy, not really. Joined avs in Dec. Opened business around the same time. AVS is the target audience, first mistake, and I really doubt Dr. G is leading this campaign....the partner likely approached Dr. G with visions of grand $$$. Lets see the price list allready.

This is ridiculous. Do you think I would stoop so low. I have been selling speakers for almost five years now. Get real.

Earl R. Geddes
GedLee
gedlee is offline  
post #205 of 2123 Old 02-27-2009, 08:22 AM
 
goneten's Avatar
 
Join Date: Dec 2002
Location: South Africa
Posts: 3,681
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 17
Dr Geddes,

Thank you for answering my questions.

Regards,
goneten is offline  
post #206 of 2123 Old 02-27-2009, 08:23 AM
Senior Member
 
pjpoes's Avatar
 
Join Date: Feb 2007
Posts: 309
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 10
Quote:
Originally Posted by simplemath View Post

Hey Penn, it almost seems like a bakyard hack pretending to be Dr. G for some ceredibility, while they sell the goods later. Or give a kickback for the name use, tied to the marketing, but on your own to market the avs site.

Conspiracy, not really. Joined avs in Dec. Opened business around the same time. AVS is the target audience, first mistake, and I really doubt Dr. G is leading this campaign....the partner likely approached Dr. G with visions of grand $$$. Lets see the price list allready.

You need to stop putting your foot in your mouth. What you are saying is incorrect. Dr. Geddes has definitely not made a lot of money of this. He worked for Ford as an acoustical scientists for some time, then went on to do various other things on what I perceive as a more consultation basis. He went into business making pro audio speakers with a partner in Asia. I don't know the full story there, but he is back here, so something didn't work out there for him. He relatively recently completed a series of research, some of which is his waveguide research, the HOM foam plug research, and the distortion audibility research. He then spent some time presenting this research. Going to his website shows links to all of these presentations, as well as the journal numbers they were published in, or patents. Looking up his name in the patent's website will link you to many more patents.

I wish him all the luck, I think his research is first rate, and the products he has developed are great. If he does start to make more money maybe he can justify moving his business into larger production and spend more of his time on further research. At the same time, I don't know that he has indicated wanting his company to take off like that.

Last I heard he has no partners in this venture, and is going this alone. He prices are available on his page, and for the type of product he is selling, they are very affordable. As for subs, while I'd love to see him begin marketing subs, it sounds to me like he is very put off by the idea. At the moment this falls under free advice on setup, not the selling of product.
pjpoes is offline  
post #207 of 2123 Old 02-27-2009, 08:23 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:
I addressed this. I never said "junk" so don't put words in my mouth. "Cheap" to me only means inexpensive not disfunctional. The B&C drivers that I use are "cheap"? Your not quoting my views in context. The point is that multiple subs will outperform one mega-buck subs when equal expense is made. I did use a cheap $100 sub for awhile and there was an improvement going to the more expensive B&C, but it wasn't night and day like multiple versus singular subs.

You said this....
Quote:
Finally all of my subs are very inexpensive, the plate amps about $100 and the B&C woofer about $150 makes up the bulk of the cost if you DIY, but the enclosures are pretty easy to build.

Im not putting words in your mouth....imo, Im describing that DIY sub as "JUNK" but you know our point of view is different. Its "JUNK" because isnt not going to do squat at the anything under 25Hz, its not a HT sub design at all.

You are using this as your challenge to everyone that has more expensive subs.

I contest those subs vs any decent HT subs and I will contest that your room design/treatments have more to do with this whole debate then you lead on.

Place those subs in normal 'non-treated' room, dont EQ and post the measurements...if are going to make a point about your theories then the measurements should look good in that room too, correct?

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #208 of 2123 Old 02-27-2009, 08:25 AM
otk
AVS Special Member
 
otk's Avatar
 
Join Date: Jul 2006
Posts: 7,496
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 15
Quote:
Originally Posted by gedlee View Post

This comment is rude. I was asked to come here and if I am not wanted I will go away.

ignore the Neanderthals. most of them are only interested in tooting their own horns about how loud their system can play 10hz. they don't even care about the frequencies you can actually hear or the sound quality of them

they want cone based butt kickers. anything over 20hz doesn't interest them in the least

it sounds like you're all about the sound quality of music from 25hz on up which a lot of people are interested in, just not the ones with the loudest mouths in this forum though

you might want to start a thread in the audio theory forum

All this noise about noise.
♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫♪♫
Finding the acoustic sweet spot.
otk is offline  
post #209 of 2123 Old 02-27-2009, 08:27 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:
The point is that multiple subs will outperform one mega-buck subs when equal expense is made.

Never argued that, I have always agreed. Maybe you should not have try to convince everyone using even the cheapest of designs will work?

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
post #210 of 2123 Old 02-27-2009, 08:30 AM
AVS Addicted Member
 
penngray's Avatar
 
Join Date: Feb 2006
Location: Florida
Posts: 26,779
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Liked: 30
Quote:
ignore the Neanderthals. most of them are only interested in tooting their own horns about how loud their system can play 10hz. they don't even care about the frequencies you can actually hear or the sound quality of them

they want cone based butt kickers. anything over 20hz doesn't interest them in the least

it sounds like you're all about the sound quality of music from 25hz on up which a lot of people are interested in, just not the ones with the loudest mouths in this forum though

you might want to start a thread in the audio theory forum

How about creating a thread talking about music...duh!


Do not pass off a music discussion thread as generic sub design/setup thread! I said this a long time ago...the thread title has been wrong since the start.

Although, my sub design better handle both but some of you do not have HT setup and that is fine.

It is not "open-minded" to reject knowledge - Bob Lee
penngray is offline  
Reply Subwoofers, Bass, and Transducers

Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page


Forum Jump: 

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