posted
I refrained from posting here for a couple of days just to observe the posts regarding the new L7 woofers, Alma and 180 db, good product vs. better product vs. the best product (ie. my/your product).
Here's my laundry list:
The L7 "test" mentioned in another post in wich the cones supposedly shredded NEVER HAPPENED - THE TEST WAS BOGUS! Please let this dog die!
I got involved in this topic at the request of Alma (Thanks by the way, I've enjoyed it in an off-way). I continued responding only because I think its important for people to step back and look again befor they make a claim for or against any product.
Excursion is not the be-all end-all when it comes to a woofers performance. Neither is Vas, Blah, or Blah. Pick any techno term or spec you wish to trip over - not a single one alone will make you louder or make your woofer of choice better. Argue till your blue in the face - someone else will be devoting their time to system planning and real world product trials.
I used Digital Designs woofer specs in a previous post in order to make a statement regarding the use of product specs and terms when evaluating woofers. This spec comparison should never have been interpreted as a product comparison - it was just to prove a point. I cant compare two different woofers without without giving them each a fair, real-world, evaluation. Neither can anyone else.
The L7 probably wasn't designed as a SPL monster.
Neither was the flat piston PPI.
The Flat piston PPI, with some creative and well thought out system engineering, proved to be a solid performer. Understatement.
The L7, with some creative and well thought out........you get the idea.
Application, Application, Application.
I don't know that much about speaker mechanics, T/S parameters, Enclosure design or pressure vehicles. I just have a sensitive B.S. meter and can tell when other people dont either.
There's always going to be a flavor of the day when it comes to product. Just because you can't pick your own doen't give you the right to lick someone elses.
I've enjoyed the debates here. I continue to learn every time I read the posts here (well filtered of course). It's great to pick up information from people that really know their stuff.
Chris Nelson
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Posts: 122 | From: Omaha, Ne. | Registered: Jun 1999
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posted
if only everyone could step back, read closely, and take it to heart. Specs mean very little sometimes. And not everyone does things the conventional way. Heck, i treid to use JL w6's(everyone knows they are great SQ woofers), and well...that failed....but i've seen many other people use unconventional means to achive their goal. why not? why do what everyone else does?
posted
First off chris i want you to know that i believe you to be a good resource, and i agree with you upon many points.
I resulted to the same level as you with the cone shredding situation. That peaked my "b.s. meter" also. But i would still be hesitant because it is just my nature.
I agree that it is very important for people to step back and give all products a fair opportunity.
I never once said that excursion was the be all and end all. The main comment i made about this parameter is that it controls the SPL of the subwoofer as well as other factors such as moving mass. I dont care how much anyone plans anything or tries anything the parameters of the subwoofer stay the same. Granted most of them dont completely alter the speakers performance you cannot just "change" one of them. Also if you let me pick one to change, i would pick Re. If this # was dropped to 0 i dont think your subs would play the same do you? Im no engineer, but i understand that these parameters can at least alter the subs performance at a "noticeable" level if +- by a considerable amount...
The L7s were not designed for SPL. I understand there was success with the flat piston woofers, but alma doesnt hold the world record does she?
I dont have any personal problems with stillwater. I currently run 2 8" comps in my parents blazer and couldnt be more happy for the price. Also kicker has an excellent technical staff. I recieved the T/S parameters just days after i consented their company via e-mail.
OK i think i addressed everything and i didnt proofread so there may be a few incorrect statements on my part. Please do not take my comments to critical, and also please try to remember that im only 16 years old and still trying to learn about this stuff... Thanx
------------------ Cerwin Vega / Legacy / Sony / Infinity
quote:Originally posted by cln: I refrained from posting here for a couple of days just to observe the posts regarding the new L7 woofers, Alma and 180 db, good product vs. better product vs. the best product (ie. my/your product).
Here's my laundry list:
The L7 "test" mentioned in another post in wich the cones supposedly shredded NEVER HAPPENED - THE TEST WAS BOGUS! Please let this dog die!
I got involved in this topic at the request of Alma (Thanks by the way, I've enjoyed it in an off-way). I continued responding only because I think its important for people to step back and look again befor they make a claim for or against any product.
Excursion is not the be-all end-all when it comes to a woofers performance. Neither is Vas, Blah, or Blah. Pick any techno term or spec you wish to trip over - not a single one alone will make you louder or make your woofer of choice better. Argue till your blue in the face - someone else will be devoting their time to system planning and real world product trials.
I used Digital Designs woofer specs in a previous post in order to make a statement regarding the use of product specs and terms when evaluating woofers. This spec comparison should never have been interpreted as a product comparison - it was just to prove a point. I cant compare two different woofers without without giving them each a fair, real-world, evaluation. Neither can anyone else.
The L7 probably wasn't designed as a SPL monster.
Neither was the flat piston PPI.
The Flat piston PPI, with some creative and well thought out system engineering, proved to be a solid performer. Understatement.
The L7, with some creative and well thought out........you get the idea.
Application, Application, Application.
I don't know that much about speaker mechanics, T/S parameters, Enclosure design or pressure vehicles. I just have a sensitive B.S. meter and can tell when other people dont either.
There's always going to be a flavor of the day when it comes to product. Just because you can't pick your own doen't give you the right to lick someone elses.
I've enjoyed the debates here. I continue to learn every time I read the posts here (well filtered of course). It's great to pick up information from people that really know their stuff.
Chris Nelson
Chris, thank you for coming back in - I locked the other post because it was getting out of hand. I really appreciate you giving your time to this forum.
------------------ Alma Gates
Posts: 3134 | From: phoenix, arizona - usa | Registered: Aug 1999
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posted
I also want to thank you Chris for sharing your knowldege with the rest of us, now if we can only get you to share your wealth also (haha). Good Luck and God Bless.
posted
Alma, In your last post in the other section it did look like you got a little upset and that is why I thought you closed it. Chris, I hope it wasn't me that sparked anything off in the other post about the VAS and I do agree with what you said in the above.
Joe
------------------ If Your Ears Arn't Bleeding....
Somethings Wrong With Your Equipment.
Posts: 1037 | From: Not where you are! | Registered: Apr 2000
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posted
No Joe, you had nothing to do with my decision to close that post. It was just time - the conversation was going nowhere and it was time to stop it. I knew Chris would post if he has anything to say. But thank you for your concern.
------------------ Alma Gates
Posts: 3134 | From: phoenix, arizona - usa | Registered: Aug 1999
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posted
WOW! I have missed a lot the past few days! I agree that specs are important, because if they didn't matter all car audio systems everywhere would be a big guessing game and all trial and error. But they are not. I wouldn't pick L7s as my first choice for SPL either, but I am one of the believers that application is 75% of the end product. As such, I don't really see any reason why they couldn't be made into SPL monsters either. They have high cone mass and low Fs and yada yada yada, but all of these can be compensated for and overcame with a lot of power and good enclosure design, along with the obvious advantage of more cone area and decent cone travel. If you have to rely on your product with no expectation of planning and design, you are in for a long losing season. I am sure Alma and the Team Gates crew have something up their sleeves as far as knowing the limits and capabilities of the Kicker equipment and I am sure the haters will be surprised when the ol' Bronco comes rolling through the lanes. I wish them the best of luck, but I have a feeling they won't be needing it.. Posts: 5349 | From: Nash-Vegas, TN | Registered: May 1999
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quote:Originally posted by spl2000: Alma: Did you delete Patrick's post? It was REALLY good. I was just wondering where it went.
Yes I did. It was the first time I have ever done that - and it was my sons! It was a good post, but I was afraid too many people would take it the wrong way and that it was too aggressive for in here. It would have fit in RAC. Do you really think it would be ok in here? At least you read it.
------------------ Alma Gates
Posts: 3134 | From: phoenix, arizona - usa | Registered: Aug 1999
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posted
Well thank you buzz you just intellegently summed up my thoughts. I cant express exactly what i feel in one post. Im sure Team Gates will get as much as they can out of the L7s and end up with a successful SPL vehicle.
------------------ Cerwin Vega / Legacy / Sony / Infinity
posted
The way I see it, there are two camps when it comes to design philosophies on SPL vehicles- the shear displacement camp and the frequency camp. Shear displacement would say that the greater the excursion/displacement of the speaker is a factor in SPL vehicles because SPL is a function of air pressure (PSI). While the other camp says this is not necessarily true, you just need to tune the box to the resonant frequency of the car and hit the mike with the 1/4 or 3/4 wave of that frequency. So whose right? Both are because you are dealing both with waves and particles, but neither camp is dealing with both- there is no unified theory of SPL, yet.
The point of that, there are speaker parameters that are important- depending on what camp you come from.
This isn't all an art, yes there is an art to building SPL cars, but you can't escape science.
[This message has been edited by winslow (edited 05-18-2000).]
Posts: 7996 | From: Charlotte,NC USA | Registered: May 1999
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posted
75 is in liters on the DD site. 75 liters is like 3 cu ft. a 3ft VAS is a very stiff suspension. The 9.9 cu ft is a looser suspension (L7) When looking at most mass marketed subs such as JL, kicker, MTX, and etc. the VAS is going to be higher due to the way the sub is designed. DD has a very high restoring force built in and thus the FS of the diver is higher also. Nohting is wrong in either situation just two differently designed drivers. oops sorry I ment to post ---> its 75 liters not 75 or 7.5 Cu Ft
posted
Glad you pointed that out. When looking at the Vas listing on the web site it lists Vas in "cu. ft./(liters)". I assumed that if the spec was liters it would have been in parenthesis. Proof that you should never assume! By the information in you post you seem to have a pretty good handle on speaker specs and I'm guessing you realized where I was going with that post. Thanks for the input.
Chris Nelson
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Posts: 122 | From: Omaha, Ne. | Registered: Jun 1999
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posted
Has sent me the T/S parameters. For those who believe these specifications to be relavent material here they are (these came directly from the Stillwater Technical staff):
Those were all the parameters specified for the L7-15451. That is the 15" duel 2 ohm voice coil sub, however, the other models are similar but not exact.
Chris you seem to be more apparent to these parameters now that other people are sighting them as important to an SPL application?
------------------ Cerwin Vega / Legacy / Sony / Infinity
posted
By the way excellent post winslow, i learned from it and agree with everything you said. I wish more people would go with the theory that science cannot be escaped.
------------------ Cerwin Vega / Legacy / Sony / Infinity
posted
Yup. I agree. Science and physics do apply in PRINCIPLE. But, I havent seen many pocket protectors in the winners circle. If It was as easy a opening a book and crunching numbers we'd all be bored by now. I can open a book and find the same thoeries and equations regarding pressure that are refered to so often (I wont understand them - but I can find'em). Heck, Richard Clark should have this whole gig wrapped up by now, shouldn't he? I've never seen so much information come from anyone. Fact of the matter is - even this guru stumbled with spl vehicles.(I hate to ever mention names of people I've never met personally, but I'm pretty sure Richard knows his stuff.) If its all science and physics, somebody better be telln'em top fuel draggers. Those silly fellers just keep goin faster and faster! Howz come? The gas engine has been around for years - shouldnt we have mastered that puppy by now - I mean with science and physics and all? Application, Application, Application.
Chris Nelson
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Posts: 122 | From: Omaha, Ne. | Registered: Jun 1999
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hey Chris This is Randy Coles. How is business going?? Just saying hello didn't put two and two together untill I saw you were in NE. Talk to Aysha about the website and tell her the problem and say hello from me.
How about this- the foundation can be laid by science, but the final touches/tweeking is an art form. Which one is the most important? Is there "a" most important, or is it all just as important? Seems like another chicken and egg analogy to me.
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Posts: 7996 | From: Charlotte,NC USA | Registered: May 1999
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posted
I have been doing some thinking and a little asking around, and I can only come up with two T/S parameters that would have any effect /affect on high SPL (170s and up)- XMAX and BL. These really high SPL numbers will come from sealed or IB arrangements, ports won't work at pressures this high due to the nonlinear behavior of the air at this point.
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Posts: 7996 | From: Charlotte,NC USA | Registered: May 1999
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posted
Hey Winslow,I agree with everything you have said so far.But I do have to question your last statement about the loudest using sealed and not ported designs.I would say almost all of the high pressure vehicles are ported.Unless you are speaking of vehicles that WILL be producing pressures near the 175+ mark.Just trying to clarify...Thanks!
------------------ MEGAJAM B.A.S.S. Bad~Ass~Sound~Systems Real men do IT on the DASH! DB DRAG RACING,a sensation as hard to forget as it is to ignore
posted
Right now the big numbers are coming from ported boxes, but I bet those numbers will begin to plateau once we start reaching 175+ dBs. This will be due to the nonlinear nature of the air.
Remember that ported boxes also rely on the air inside the box to act as a spring.
Work defined classically is the force required to move an object over a given distance. And when we talk about speakers and the work being done to the system (the interior of the car in this case) and inorder to increase the work being done to the system, you must increase these two variables. How do you do that? Make the speaker move more with a stronger motor- more XMAX and higher BL. Atleast that is my hypothesis, and it works according to what I know about linear physics.
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Posts: 7996 | From: Charlotte,NC USA | Registered: May 1999
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posted
Ahhhh - this is good stuff! Over my head, but good stuff! Thanks for the good input. Heh Randy - good to hear from you. I need to get in touch w/ Aysha on a number of topics - I'd be glad to say hello for you. Drop me an E-mail and let me know what your up to.
Chris Nelson carbuyer@stereowest.com
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Posts: 122 | From: Omaha, Ne. | Registered: Jun 1999
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