What about Deflex?
04-02-02, 05:17 PM
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What about Deflex?
Percy is the man.
No question.
He says a pad of deflex behind the door speakers makes a big difference. I believe him, as do most of you I assume.
Then, today, I'm talking to this guy who has been building speaker enclosures for years and knows car audio engineering and he says that deflex ain't necessary. Reason he says is because the door is too shallow and the wave frequencies don't have far enough to travel to bounce off the surface behind the speaker and then get projected out the front of the speaker, thereby muddying up the sound. He said the theory behind it is correct, but there physically isn't enough distance for the waves to travel to present a problem.
Who has an opinion on this?
No question.
He says a pad of deflex behind the door speakers makes a big difference. I believe him, as do most of you I assume.
Then, today, I'm talking to this guy who has been building speaker enclosures for years and knows car audio engineering and he says that deflex ain't necessary. Reason he says is because the door is too shallow and the wave frequencies don't have far enough to travel to bounce off the surface behind the speaker and then get projected out the front of the speaker, thereby muddying up the sound. He said the theory behind it is correct, but there physically isn't enough distance for the waves to travel to present a problem.
Who has an opinion on this?
04-02-02, 07:39 PM
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Bobcat - Hopefully Percy will jump in here. This is not my field of expertise but I have spent a few decades of my life learning and implementing physics so here is my view. I am not sure what difference distance makes on the back side of the enclosure. That is not to say that your contact is not right but at 300 Hz, the wavelength we are working with is about one megameter so any of these enclosure dimensions are trivial compared to the wavelength of the signal. I can raise the argument that the closer the back side of the enclosure (and hence a potential reflector) is to the speaker, the more interference will be created from a back reflection. We are trying to seal the door up, just like a sub enclosure, so we obviously have a condition more of a standing wave although the frequency is changing. If this sounds like it gets complex quickly, I think it does. I have great respect for the people with hands on expertise in this industry but the technical specs for the Deflex was to clean the signal out of the front of the speaker/enclosure by reducing or eliminating the direct influence of the reflection on the back of the speaker. Seems OK by me and Percy does vouch for the stuff. If I am going to go through the anguish of taking the doggoned door panel off, removing the stock speakers, fabricating the baffle, sound deadening as much as I can, installing the Deflex seems like a minor issue and I don't technically see any downside so I am cool with it. Now if Percy could add the more appropriate geek speak we will probably all feel better and I can go back to figuring out why Percy says the rear door speakers do their job better if you reverse polarity. PhD in physics and I still have so much to learn.
04-02-02, 09:05 PM
#3
Moderator - Electronics Forum
Re: What about Deflex?
Originally posted by Bobcat
Percy is the man.
No question.
He says a pad of deflex behind the door speakers makes a big difference. I believe him, as do most of you I assume.
Then, today, I'm talking to this guy who has been building speaker enclosures for years and knows car audio engineering and he says that deflex ain't necessary.
***He hasn't tried it any other way probably. There have been MLSSA and RTA tests done with AND without Deflex with all types of speaker enclosures. Bottom line...they work.
Reason he says is because the door is too shallow and the wave frequencies don't have far enough to travel to bounce off the surface behind the speaker and then get projected out the front of the speaker, thereby muddying up the sound. He said the theory behind it is correct, but there physically isn't enough distance for the waves to travel to present a problem.
***You could probably say the same about polyester fiberfill in subwoofer enclosures. With most sub enclosures the box is around 1 to 2 cubic feet per driver, depending on the drivers specs. A full blown wavelength at those frequencies will take several feet to "mature" but the fiberfill helps and it WORKS. Same thing with Deflex, only better.
Who has an opinion on this?
Percy is the man.
No question.
He says a pad of deflex behind the door speakers makes a big difference. I believe him, as do most of you I assume.
Then, today, I'm talking to this guy who has been building speaker enclosures for years and knows car audio engineering and he says that deflex ain't necessary.
***He hasn't tried it any other way probably. There have been MLSSA and RTA tests done with AND without Deflex with all types of speaker enclosures. Bottom line...they work.
Reason he says is because the door is too shallow and the wave frequencies don't have far enough to travel to bounce off the surface behind the speaker and then get projected out the front of the speaker, thereby muddying up the sound. He said the theory behind it is correct, but there physically isn't enough distance for the waves to travel to present a problem.
***You could probably say the same about polyester fiberfill in subwoofer enclosures. With most sub enclosures the box is around 1 to 2 cubic feet per driver, depending on the drivers specs. A full blown wavelength at those frequencies will take several feet to "mature" but the fiberfill helps and it WORKS. Same thing with Deflex, only better.
Who has an opinion on this?
Percy
04-02-02, 09:05 PM
#4
Search Function Inc.
I did exactly what Ron said with the custom baffles. After installing Deflex there was considerable difference in sound. It was playing louder, cleaner and had more impact to sound. I am pretty sure that Deflex will help some when the distance from a speaker is very short due to a form of the material. Some standing waves will go away.
04-02-02, 09:08 PM
#5
Moderator - Electronics Forum
Originally posted by RON430
Bobcat - Hopefully Percy will jump in here. This is not my field of expertise but I have spent a few decades of my life learning and implementing physics so here is my view. I am not sure what difference distance makes on the back side of the enclosure. That is not to say that your contact is not right but at 300 Hz, the wavelength we are working with is about one megameter so any of these enclosure dimensions are trivial compared to the wavelength of the signal. I can raise the argument that the closer the back side of the enclosure (and hence a potential reflector) is to the speaker, the more interference will be created from a back reflection. We are trying to seal the door up, just like a sub enclosure, so we obviously have a condition more of a standing wave although the frequency is changing. If this sounds like it gets complex quickly, I think it does. I have great respect for the people with hands on expertise in this industry but the technical specs for the Deflex was to clean the signal out of the front of the speaker/enclosure by reducing or eliminating the direct influence of the reflection on the back of the speaker. Seems OK by me and Percy does vouch for the stuff. If I am going to go through the anguish of taking the doggoned door panel off, removing the stock speakers, fabricating the baffle, sound deadening as much as I can, installing the Deflex seems like a minor issue and I don't technically see any downside so I am cool with it. Now if Percy could add the more appropriate geek speak we will probably all feel better and I can go back to figuring out why Percy says the rear door speakers do their job better if you reverse polarity. PhD in physics and I still have so much to learn.
Bobcat - Hopefully Percy will jump in here. This is not my field of expertise but I have spent a few decades of my life learning and implementing physics so here is my view. I am not sure what difference distance makes on the back side of the enclosure. That is not to say that your contact is not right but at 300 Hz, the wavelength we are working with is about one megameter so any of these enclosure dimensions are trivial compared to the wavelength of the signal. I can raise the argument that the closer the back side of the enclosure (and hence a potential reflector) is to the speaker, the more interference will be created from a back reflection. We are trying to seal the door up, just like a sub enclosure, so we obviously have a condition more of a standing wave although the frequency is changing. If this sounds like it gets complex quickly, I think it does. I have great respect for the people with hands on expertise in this industry but the technical specs for the Deflex was to clean the signal out of the front of the speaker/enclosure by reducing or eliminating the direct influence of the reflection on the back of the speaker. Seems OK by me and Percy does vouch for the stuff. If I am going to go through the anguish of taking the doggoned door panel off, removing the stock speakers, fabricating the baffle, sound deadening as much as I can, installing the Deflex seems like a minor issue and I don't technically see any downside so I am cool with it. Now if Percy could add the more appropriate geek speak we will probably all feel better and I can go back to figuring out why Percy says the rear door speakers do their job better if you reverse polarity. PhD in physics and I still have so much to learn.
We all have lots to learn. It's only that people with advanced degrees will realize this much sooner (or later as you're earning the degree)! The more we know the less we understand!
As for the speaker reverse polarity in the rears, it's basically narrows down to a time delay. Try it...worked out great in my installation (GP) and I was very surprised at this.
Percy
04-02-02, 10:09 PM
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Ron ...let me know how you stick the deflex onto the door. I tried all sorts of adhesives and finally got it to stick. If your panel is anything like mine...it's kinda oily feeling and slippery which makes it difficult to stay on.
I never tried it without the deflex but i figured it's only 20 bucks...ive already gone all out..what the hell...
I'd say you guys sure have an open mind in audio. Lots of die hard physicists and engineers still refuse to believe LPs and Tube can sound good. My roomate was trying to convince me I have wasted my money on my Denon DVD player because the Playstation 2 could have done the exact same thing. My reply was that the Denon sounds better as a CD player and is also a superior DVD player....his reply "well if they're all encoded at the same bit rate then...blah blah blah" In a sense..he's lucky he can't differentiate or doesn't care for good quality cuz audio as a hobby is really really expensive.
I never tried it without the deflex but i figured it's only 20 bucks...ive already gone all out..what the hell...
I'd say you guys sure have an open mind in audio. Lots of die hard physicists and engineers still refuse to believe LPs and Tube can sound good. My roomate was trying to convince me I have wasted my money on my Denon DVD player because the Playstation 2 could have done the exact same thing. My reply was that the Denon sounds better as a CD player and is also a superior DVD player....his reply "well if they're all encoded at the same bit rate then...blah blah blah" In a sense..he's lucky he can't differentiate or doesn't care for good quality cuz audio as a hobby is really really expensive.
04-03-02, 06:06 AM
#7
Moderator - Electronics Forum
amlin423,
Get that engineer buddy of yours on this board and he'll learn a thing or two.
PS2 vs Denon. Yeah, same bit rates but what about the power supply and clock? (They're not of the same quality). Now how about the analog output? They're also not the same quality. They're both based on the same principle but in final application of parts, they're QUITE different. Think it doesn't matter? IT DOES.
LP...The closest thing that I've come to a true high end rig is SACD playing SACD material. LP, with the high end turntable, cartridge and proper preamp, (and a good 180gm pressing) will still sound better than most CD. HDCD is close, SACD is better. There's a clinical "leanness" to most cd sources.
For some reason SACD absolutely SUCKS when playing back regular CD. I just picked up the Sony Flagship SCD-1 (5k) to pit against my Krell. Krell wastes it on regular cd and actually ties on HDCD vs SACD playback. But, thats fully modded (Krell) and the SCD-1 is bone stock. Time to mod out the SCD-1, then it'll easily beat out the Krell.
Percy
Get that engineer buddy of yours on this board and he'll learn a thing or two.
PS2 vs Denon. Yeah, same bit rates but what about the power supply and clock? (They're not of the same quality). Now how about the analog output? They're also not the same quality. They're both based on the same principle but in final application of parts, they're QUITE different. Think it doesn't matter? IT DOES.
LP...The closest thing that I've come to a true high end rig is SACD playing SACD material. LP, with the high end turntable, cartridge and proper preamp, (and a good 180gm pressing) will still sound better than most CD. HDCD is close, SACD is better. There's a clinical "leanness" to most cd sources.
For some reason SACD absolutely SUCKS when playing back regular CD. I just picked up the Sony Flagship SCD-1 (5k) to pit against my Krell. Krell wastes it on regular cd and actually ties on HDCD vs SACD playback. But, thats fully modded (Krell) and the SCD-1 is bone stock. Time to mod out the SCD-1, then it'll easily beat out the Krell.
Percy
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04-03-02, 11:18 AM
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First things first, carstereotime notified me that the speakers shipped so no complaints. Not here yet but could be today or tomorrow. Free shipping so I am not going to complain if they are here by Friday.
I ordered the Deflex in the CAE speaker kit. I agree with Percy in THE BOOK about the price of Deflex from madisound compared to CAE but it seems to only be dramatic if you order the individual pieces. madisound has the Deflex for about $13 a sheet (don't remember exactly) and the CAE version is about twice. But, if you buy the speaker kit, you get two 7" pieces of Deflex and some VB5 (I think) for 29.95 so it didn't seem to be that bad a deal. I have enough bits coming from separate vendors as it is. I did like the fact that the other CAE products are not asphalt based. Don't know if smell really is an issue but why take the chance?
Gluing rubber to steel is not going to be trivial. I have some experience in this area. First thing is going to be cleanliness. The door skin has to be really clean and grease free. I will probably use 3M adhesive remover and then isopropyl. Next is the Deflex. I am sure that it is a molded rubber product which means mold release, that slick waxy feeling, glue is not going to stick. Need to use the solvents (carefully to make sure you don't dissolve the Deflex) and clean the living daylights out of the Deflex. I know Loctite Master Gasket will work (we use it to adhere rubber vacuum seals to aluminum) but I am going to try Loctite 380 cyanoacrylate. The description on the 380 is - General purpose adhesive provides very high impact, thermal sheer, and moisture resistance - excellent resistance to peel and impact. Most CAs can be dodgy when you combine low temperatures with moisture and then apply impacts (like closing the door). Not trying to be ****, just don't want to take the bloody doors apart too many times.
Plan right now is to do the front doors, then rears (ADS 336im and I probably will reverse the polarity. Not sure my ears are good enough to notice but I can notice that I do like rear fill - not trying to open that one up for discussion, probably a personal choice). Then move on to the sub, I am going to use the Dynaudio free air just don't know if I will use the 10 (I have seen it called more like 9 1/2) or the 12. Finally, an amp. Hey Percy, I know the Mac performance is still top drawer but I have noticed that finally some people are taking the SQ properties to heart. Seems like there are more amps being advertised with much improved specs (about time) although availability is still pretty gruesome. With apologies to the guys involved there are a lot of amps being tested and splashed but getting them takes a note from god. They are definitely trying to get market share by coming in under the Mac pricing, wonder if they are going to be any good?
I have had an ScD for over 25 years and I normally don't go out of my way to bring it up. Just don't like most PhDs I have met. That "ears stuck on their hemmorhoids" attitude that gets implanted in grad school can be, shall we say, a turnoff? There are some very good folks running around and don't underestimate the value of someone who intimately understands theory versus a tinkerer but a degree surely doesn't mean you know everything about everything. Also doesn't help when you are dangling by your knees upside down in the trunk trying to get a sub in but that probably is another thread.
I ordered the Deflex in the CAE speaker kit. I agree with Percy in THE BOOK about the price of Deflex from madisound compared to CAE but it seems to only be dramatic if you order the individual pieces. madisound has the Deflex for about $13 a sheet (don't remember exactly) and the CAE version is about twice. But, if you buy the speaker kit, you get two 7" pieces of Deflex and some VB5 (I think) for 29.95 so it didn't seem to be that bad a deal. I have enough bits coming from separate vendors as it is. I did like the fact that the other CAE products are not asphalt based. Don't know if smell really is an issue but why take the chance?
Gluing rubber to steel is not going to be trivial. I have some experience in this area. First thing is going to be cleanliness. The door skin has to be really clean and grease free. I will probably use 3M adhesive remover and then isopropyl. Next is the Deflex. I am sure that it is a molded rubber product which means mold release, that slick waxy feeling, glue is not going to stick. Need to use the solvents (carefully to make sure you don't dissolve the Deflex) and clean the living daylights out of the Deflex. I know Loctite Master Gasket will work (we use it to adhere rubber vacuum seals to aluminum) but I am going to try Loctite 380 cyanoacrylate. The description on the 380 is - General purpose adhesive provides very high impact, thermal sheer, and moisture resistance - excellent resistance to peel and impact. Most CAs can be dodgy when you combine low temperatures with moisture and then apply impacts (like closing the door). Not trying to be ****, just don't want to take the bloody doors apart too many times.
Plan right now is to do the front doors, then rears (ADS 336im and I probably will reverse the polarity. Not sure my ears are good enough to notice but I can notice that I do like rear fill - not trying to open that one up for discussion, probably a personal choice). Then move on to the sub, I am going to use the Dynaudio free air just don't know if I will use the 10 (I have seen it called more like 9 1/2) or the 12. Finally, an amp. Hey Percy, I know the Mac performance is still top drawer but I have noticed that finally some people are taking the SQ properties to heart. Seems like there are more amps being advertised with much improved specs (about time) although availability is still pretty gruesome. With apologies to the guys involved there are a lot of amps being tested and splashed but getting them takes a note from god. They are definitely trying to get market share by coming in under the Mac pricing, wonder if they are going to be any good?
I have had an ScD for over 25 years and I normally don't go out of my way to bring it up. Just don't like most PhDs I have met. That "ears stuck on their hemmorhoids" attitude that gets implanted in grad school can be, shall we say, a turnoff? There are some very good folks running around and don't underestimate the value of someone who intimately understands theory versus a tinkerer but a degree surely doesn't mean you know everything about everything. Also doesn't help when you are dangling by your knees upside down in the trunk trying to get a sub in but that probably is another thread.
04-03-02, 04:05 PM
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Got mine from Madisound.
The reason mine was so difficult to ahere (probably even harder than most of you) was because I also have a layer of sound dampening beneath the deflex. It's not a smooth smooth surface but I eventually managed to have it stick on. Actually, I'm not sure if it's still on but my car sounds good and I sure as hell would not want to take apart my car again.
The reason mine was so difficult to ahere (probably even harder than most of you) was because I also have a layer of sound dampening beneath the deflex. It's not a smooth smooth surface but I eventually managed to have it stick on. Actually, I'm not sure if it's still on but my car sounds good and I sure as hell would not want to take apart my car again.
04-03-02, 05:58 PM
#11
Moderator - Electronics Forum
[QUOTE]Originally posted by RON430
. Hey Percy, I know the Mac performance is still top drawer but I have noticed that finally some people are taking the SQ properties to heart. Seems like there are more amps being advertised with much improved specs (about time) although availability is still pretty gruesome. With apologies to the guys involved there are a lot of amps being tested and splashed but getting them takes a note from god. They are definitely trying to get market share by coming in under the Mac pricing, wonder if they are going to be any good?
***The only thing near a Mc would be the Brax. Also, the Brax ADVERTISES near Godlike(tm) specs but in real measurements they weren't even close. Plus Mc puts alot of patented stuff in their amps, REAL useful stuff, not a patent on the shape of an external casing.
I have had an ScD for over 25 years and I normally don't go out of my way to bring it up. Just don't like most PhDs I have met. That "ears stuck on their hemmorhoids" attitude that gets implanted in grad school can be, shall we say, a turnoff? There are some very good folks running around and don't underestimate the value of someone who intimately understands theory versus a tinkerer but a degree surely doesn't mean you know everything about everything.
***AGREED! Most of the "big wigs" that I've met failed to look beyond the scope of the theory.
Also doesn't help when you are dangling by your knees upside down in the trunk trying to get a sub in but that probably is another thread.
***Pizza and Pepsi in the trunk...a staple meal of the audio installer. Oh yeah...back cramps too!
Percy
. Hey Percy, I know the Mac performance is still top drawer but I have noticed that finally some people are taking the SQ properties to heart. Seems like there are more amps being advertised with much improved specs (about time) although availability is still pretty gruesome. With apologies to the guys involved there are a lot of amps being tested and splashed but getting them takes a note from god. They are definitely trying to get market share by coming in under the Mac pricing, wonder if they are going to be any good?
***The only thing near a Mc would be the Brax. Also, the Brax ADVERTISES near Godlike(tm) specs but in real measurements they weren't even close. Plus Mc puts alot of patented stuff in their amps, REAL useful stuff, not a patent on the shape of an external casing.
I have had an ScD for over 25 years and I normally don't go out of my way to bring it up. Just don't like most PhDs I have met. That "ears stuck on their hemmorhoids" attitude that gets implanted in grad school can be, shall we say, a turnoff? There are some very good folks running around and don't underestimate the value of someone who intimately understands theory versus a tinkerer but a degree surely doesn't mean you know everything about everything.
***AGREED! Most of the "big wigs" that I've met failed to look beyond the scope of the theory.
Also doesn't help when you are dangling by your knees upside down in the trunk trying to get a sub in but that probably is another thread.
***Pizza and Pepsi in the trunk...a staple meal of the audio installer. Oh yeah...back cramps too!
Percy
04-03-02, 07:24 PM
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Thanks Percy. I got the Car Audio buyers guide and noiced the audioson amps. At least on paper they give me a stronger subwoofer output than a Mac but then the Mac puts out more than the specs so who knows. But now you have not only Brax, and their cubscout Helix line, as well as Milbert, Genesis, and more than I can remember, that at least know how to play the advertising game. Amp will still be last on the list, have to see what develops.
By the way, I left out something else we developed for adhering rubber to metal. The first clean is an aqeous solution of surfactants to remove water soluble contaminants combined with some hydrocarbon grease emulsifiers in an elevated temperature solution. That's right, wait for it, warm soapy water. I will do that to the Deflex first. Thanks amlin 423 you answered my unasked question and saved me spinning my wheels seeing if Deflex would adhere to the vibration dampeners. I wonder if any other car marque has a resource like this board available to them?
By the way, I left out something else we developed for adhering rubber to metal. The first clean is an aqeous solution of surfactants to remove water soluble contaminants combined with some hydrocarbon grease emulsifiers in an elevated temperature solution. That's right, wait for it, warm soapy water. I will do that to the Deflex first. Thanks amlin 423 you answered my unasked question and saved me spinning my wheels seeing if Deflex would adhere to the vibration dampeners. I wonder if any other car marque has a resource like this board available to them?
04-04-02, 11:57 AM
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Ron, It might depend on what deadening device you're using. If you're using dynamat, then it should be alright since they are smooth. I am using Raamat which looks like...hmm...can't describe it...here's a link to ebay
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1343806535
I personally love how easy it was to apply. There's no need for rollers or heat gun....plus the guy that's selling it (Rick) is a really great guy. Ask him anything and he'll give you an honest straight up answer. Retro and him seem to be buddies so you can ask him for details.
If you're going to use the stock amps to drive the dyns then you're probably going to be pretty disappointed. I'm sure once you drop the dyns in...you would rush out to get a quality amp to go with them. The difference will definitely blow you away.
http://cgi.ebay.com/ws/eBayISAPI.dll...tem=1343806535
I personally love how easy it was to apply. There's no need for rollers or heat gun....plus the guy that's selling it (Rick) is a really great guy. Ask him anything and he'll give you an honest straight up answer. Retro and him seem to be buddies so you can ask him for details.
If you're going to use the stock amps to drive the dyns then you're probably going to be pretty disappointed. I'm sure once you drop the dyns in...you would rush out to get a quality amp to go with them. The difference will definitely blow you away.
04-04-02, 12:55 PM
#14
Search Function Inc.
well, since RAAMmat brand is flying around, check my site for special sale on that product. It is all Dynomat extreeme is but cheaper.
Twiggy, did you use the Original RAAMmat or RAAMmat60?
Twiggy, did you use the Original RAAMmat or RAAMmat60?
04-04-02, 04:31 PM
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Twiggy - Looked at a lot of the sound/vibration dampening materials -compounds out there. Most, but not all, of the thinner sheets come adhesive backed and may or may not benefit from heat to make it conform to contours. But what we have been talking about is Deflex which is a non-adhesive coated speaker back reflection reducing molded rubber product. The application of Deflex requires you to use your own adhesive with all the joys that entails to get the stuff positioned and stuck correctly. While there may be multiple sources of Deflex (or Deflex like materials) none of it is adhesive backed from what I have seen.