Re: Pro/Con Plexiglas
umm, you don't actually know a whole lot about audio... do you?
the panels of an MDF box already resonate at a higher frequency than one would expect the sub to play, therefore, a sealed plexiglass box will do bugger all to the sound output...
Now, with a ported box, MDF is DEAD, its very dense, and absorbs sound well... while a plexiglass box will echo, and I'm sure be VERY "in your face" if I was going to make a ported plexiglass box, I would sound deaden it.... wait a minute, that defeats the whole purpose...
"longest sound wave lengths" pardon?
the lower the frequency, the longer the wavelength.. I'm a little confused there.
you just said the plexi boxes gave a "gives a much louder "In your face" quality" but that the MDF boxes are louder..
can't argue with that... unless its a ported box, and then you really wouldn't want it in a boat anyway, as the salt air would cause the sub to corrode
wow, ricing up a sub box.. just what I never wanted may be a pro to some.. to me.. its a con...
you can't really count appearance as a CON... my first impression, is oh my god.. they're so damn ugly...
anyhoo... thats enough talking **** for one day...
I'm sure if someone wants a plexi sub box, you're the people to go to... but they won't sound any better (possibly even worse) than an MDF box.. and appearance is a personal preferance.
umm, you don't actually know a whole lot about audio... do you?
the panels of an MDF box already resonate at a higher frequency than one would expect the sub to play, therefore, a sealed plexiglass box will do bugger all to the sound output...
Now, with a ported box, MDF is DEAD, its very dense, and absorbs sound well... while a plexiglass box will echo, and I'm sure be VERY "in your face" if I was going to make a ported plexiglass box, I would sound deaden it.... wait a minute, that defeats the whole purpose...
"longest sound wave lengths" pardon?
the lower the frequency, the longer the wavelength.. I'm a little confused there.you just said the plexi boxes gave a "gives a much louder "In your face" quality" but that the MDF boxes are louder..
can't argue with that... unless its a ported box, and then you really wouldn't want it in a boat anyway, as the salt air would cause the sub to corrode
wow, ricing up a sub box.. just what I never wanted
may be a pro to some.. to me.. its a con...you can't really count appearance as a CON... my first impression, is oh my god.. they're so damn ugly...
anyhoo... thats enough talking **** for one day...
I'm sure if someone wants a plexi sub box, you're the people to go to... but they won't sound any better (possibly even worse) than an MDF box.. and appearance is a personal preferance.
Plexi is much more dense then MDF and much more expensive. If I remember the conversion right a 1/2" sheat of plexi is equal to a 3/4" sheet of MDF. Skinny what are you talking about when you say a ported box is dead? That simply isn't true. Ported and sealed boxes are only dead if you have correctly braced them. Don't belive me well try this. Find a mdf box with a sub in it while it is playing. Put your hand on the box. Unless the box has been braced well (and even then it still may not be 100%dead) you will feel vibration. If you don't then put your ear on the box. Do you hear sound comming from the box? Then it is not dead. In theory a 100% dead box will not vibrate at all at any freq. This is very hard to acheive and isn't really required in most situations.Well designed sub enclosures get rid of reso. one of two ways. One is to make it so that the enclosure resonates at a frequency below what the speaker plays. This is so reso. modes in the enclosures panels don't get excited. The other way is to make the enclosure resonate at a much higher freq. so that any enclosure harminics produced will be greatly reduced. If you want to hear a box that is truly dead listen to one made of marble or corian (ie wilson speakers). Any movement by the enclosure does affect the sound to some degree. MDF and plexi both do not absorb sound well. In fact they are terrible at absorbing sound, where did you get the idea that MDF was good at that? If this was true speaker companies have been wasting big money putting sound absorbtion into their speakers.
Skinny I know you like car audio but I think you need to go and research a little more. Misinformation like saying MDF is denser then plexi, MDF ported enclosures are dead, and that MDF can absorb sound well don't help others who may not know about car audio and want to learn. If you want I can post some sites that have a lot of info on them about car audio.
Skinny I know you like car audio but I think you need to go and research a little more. Misinformation like saying MDF is denser then plexi, MDF ported enclosures are dead, and that MDF can absorb sound well don't help others who may not know about car audio and want to learn. If you want I can post some sites that have a lot of info on them about car audio.
DJNUBZ said:
Stiffness isn't dependant on density, but rather thickness and modulus. While Plexi has I believe a slightly higher modulus of elasticity, that does not make up for the 50% increase in thickness going from 1/2" to 3/4". Stiffness increases with the cube of thickness for a panel. Relationship to modulus is merely linear.
There are two methods that are useful for reducing enclosure contributions to total output, and only one is really applicable to sub enclosures. The first you mention is nonsense... you would never want to lower the resonant frequency for a sub enclosure. Never. Even if the resonant frequency were below the operating range of the sub, the compliance of the panels would result in large displacements due to forced excitation. Instead, you should aim to raise the resonant frequency above the operating range of the sub as much as possible. Instead of "reducing enclosure harmonics" as you state, the goal here is to force the enclosure to operate solely in the forced vibration regime, which with stiff panels will consist of small vibrations. You don't want resonance at all.
The other valid method of reducing enclosure vibrations is to damp the resulting vibrations. This is most useful if you can't push the resonant mode above the passband of the drivers used in the enclosure... i.e., a full range speaker. Here you should aim for stiffness, not just higher resonant frequency (in other words, opt for higher stiffness even if it carries a mass penalty - which pushes the resonant frequency back down), as you will damp resonant vibrations and use the stiffness to your advantage to reduce the amplitude of forced vibrations. I should strongly note that this does not apply to typical subwoofers at all.
With subs, you should use lots of bracing and stiff materials (plywood better than MDF, but more expensive). Plexi, MDF, plywood... they can all produce good enclosures. With the higher stiffness of plexi it could be superior to MDF only if the same thickness and bracing is used... talk about a ridiculously overpriced enclosure! Much wiser to simply add more thickness or bracing to a wood enclosure. I suppose it doesn't have that bling factor though.
Sound absorption in full range enclosures is a completely different animal. What MDF does do well is damp mechanical vibrations in the panel (not absorb airborn sound waves as you misunderstood). i.e., MDF has good hysteresis damping. Better than plexi IIRC (and better than plywood as well). But again, damping (both backwave and mechanical) is only useful in full range enclosures. Not subs. Use the stiffer material if it is in your budget.
Back in the 70's....
a guy by the name of Philip R Clements started a speaker business in Texas and later after a fire and a refinanceing moved to Totonto. Phil had a little speaker (called the little D) with a 5.25 inch bass/mid driver that did a remarkable job of reproducing the low E on a bass guitar. The speakers were very good and to my ear did bass better than anything near their size. I first heard them in 88. You might find the patent interesting. At least this design made bass with a small driver and played at good levels. They made a lot of jaws drop in the several demos that I listened to. Phil is still in the business. If you want good bass extension in a little box these do work. Perhaps one of you computer savy guys can model the design.
http://www.google.com/patents?id=iH...om=4&dq=philip+r+clements+loudspeaker#PPA3,M1
a guy by the name of Philip R Clements started a speaker business in Texas and later after a fire and a refinanceing moved to Totonto. Phil had a little speaker (called the little D) with a 5.25 inch bass/mid driver that did a remarkable job of reproducing the low E on a bass guitar. The speakers were very good and to my ear did bass better than anything near their size. I first heard them in 88. You might find the patent interesting. At least this design made bass with a small driver and played at good levels. They made a lot of jaws drop in the several demos that I listened to. Phil is still in the business. If you want good bass extension in a little box these do work. Perhaps one of you computer savy guys can model the design.
http://www.google.com/patents?id=iH...om=4&dq=philip+r+clements+loudspeaker#PPA3,M1
I've had a Brahma 10 MkII in a Snailshell since '05 that was never used due to car troubles, except for toying around with it in the home a time or two way back then. It's been sitting ever since. I've only posted around a time or two over the years, and responded to people who found those posts much later on who emailed me with some interest, but I guess none of them were really serious about it. So, I haven't really put much effort into trying to sell it I guess. Anyway, Brahma MkII in its Snailshell box, been sitting up in a closet for 3-4 years.. I'll do $300 + shipping. PM me if interested.
Btw, all the images/plans/diagrams I've seen posted in this thread look nothing like the SS enclosure, or at least the parts that can be seen (behind the woofer and down the vent).
And for a single 10" woofer, it's still by far the most impressive I've ever heard. So, regardless of what it really is or isn't.. it's everything it was hyped up to be IMO. Back when I bought it, I didn't know anywhere near what I know now, but I could go pull it out right now and hook it up to something and be just as impressed as I was the first day. It works great, unbelievably loud for a single 10, and I remember it EASILY going down into the 20's in-room. Unlike anyone else that's heard them, I only played mine in a living room.. never even listened to it in a car.
Quit bashing it so much. It's not bad at all, and certainly doesn't sound bad, pretty impressive actually.
www.nolteaudio.com
edit: Here's an old pic..
Btw, all the images/plans/diagrams I've seen posted in this thread look nothing like the SS enclosure, or at least the parts that can be seen (behind the woofer and down the vent).
And for a single 10" woofer, it's still by far the most impressive I've ever heard. So, regardless of what it really is or isn't.. it's everything it was hyped up to be IMO. Back when I bought it, I didn't know anywhere near what I know now, but I could go pull it out right now and hook it up to something and be just as impressed as I was the first day. It works great, unbelievably loud for a single 10, and I remember it EASILY going down into the 20's in-room. Unlike anyone else that's heard them, I only played mine in a living room.. never even listened to it in a car.
Quit bashing it so much. It's not bad at all, and certainly doesn't sound bad, pretty impressive actually.
www.nolteaudio.com
edit: Here's an old pic..
Attachments
What an enjoyable stroll down Amnesia Lane
Yes, even with those ignorantly bashing & hating something of which they have no personal knowledge nor experience, still this strand brought back a plethora of great memories, clear back to 1995 when John and I first started building for his Mitsubishi truck.
I named the Double Shot and we both, somewhat together and somewhat separately, named the Snail Shell.
These designs came about by John modifying an enclosure design I showed him, which came about from an enclosure I designed by modifying an enclosure design which John showed me.
...You may have to re-read that once or twice.
Moot point that it may now be, (since John has moved on into the field of perfecting Medical Lasers,) his little 6.5" DS & SS enclosures were incredibly high output enclosures which followed our mutual motto of, "It's not bass unless it produces 30Hz as loudly as 50Hz".
They actually did produce levels of 25-30Hz loudly enough to bring tears to one's eyes, set off car alarms across the parking lot, and cause an uncomfortable feeling in the ear unless one was wearing ear plugs, and did so with 6.5" woofers.
A high powered, large enclosure loaded with an high end 15" it was not, but most who heard these were amazed when afterward they saw 6.5" woofers, usually uttering the most often heard response of, "No way, I thought you had at least tens, if not twelves or a fifteen!"
In Johns VW Corrado, an early (and not yet perfected) Double Shot loaded with two Audiobahn 6.5s garnered 132.7dB at 31Hz on the new Termlab meter driven only by a single Soundstream D200 amplifier, while four beefy 8" placed 147.7dB @ 33Hz on that same meter in two 8" Double Shot enclosures in the rear of a VW Golf, driven by one MTX 1000w amp, no electrical mods to either vehicle.
They weren't designed with SPL in mind, nor solely with SQ in mind, but both. We called them SQL enclosures for 'Sound Quality - Loud'.
- Bad grammar, but accurate.
The videos with the odd looking enclosures were not in any way faked, and were using an enclosure design of mine which I asked John NOT to make public, hence the hush hush regarding those.
However that was the design upon which both the SS & DS were loosely based, and was included for the purpose of showing the possibility of getting truly sub-frequencies from such a diminutive woofer.
I once asked John if I could use a Snail Shell he had built for someone who called and ordered it for a Fosgate 12" but then called back and changed the order to one for a DD 12".
I saw him put the enclosure up into the overhead warehouse storage and hating to see waste I asked, "Hey John, how about I buy that and use my ID Max 12 in it"?
He said, "NO WAY! It's not designed for it and I don't want my name on something which won't perform correctly".
An honorable man, John Nolte, and an amazing abstract genius with both a talent and a penchant for audio, among other mechanical & scientific pursuits.
In his home he is currently listening to two 6.5" Double Shot enclosures, each with a two-way 360° midrange disperser on top below it's tweeter, which he built as prototypes.
Each enclosure has it's own 150w sub amp and he keeps them set on 3/10 or it would have seriously detrimental effects on the dinnerware, animals and fish which reside in the house.
Too bad not everyone can hear these shake his home.
On Enya's album Watermark, the song The Long Ships has a 27Hz note. When he plays that at a medium listening level I can see his glass sliding doors flex enough to warrant sitting well away from them and while doing so if I watch the woofer cones I see they are barely moving, an efficient enclosure design to say the least, with only four 6.5" EU-700 woofers & 300w.
Maybe John will one day begin making a few more for special orders, but for now he's had his fun in car audio and has moved well into home audio.
- Again, and for posterity, there is nothing faked in any of those now long-gone videos, and instead of buttering each other's bread about all the imagined reasons you have for belittling those truly incredible enclosures, would you have had the opportunity to actually experience hearing & feeling one you'd instead be debating all the possible reasons for why they do work so well.
Oh well, time marches on.
Yes, even with those ignorantly bashing & hating something of which they have no personal knowledge nor experience, still this strand brought back a plethora of great memories, clear back to 1995 when John and I first started building for his Mitsubishi truck.
I named the Double Shot and we both, somewhat together and somewhat separately, named the Snail Shell.
These designs came about by John modifying an enclosure design I showed him, which came about from an enclosure I designed by modifying an enclosure design which John showed me.
...You may have to re-read that once or twice.
Moot point that it may now be, (since John has moved on into the field of perfecting Medical Lasers,) his little 6.5" DS & SS enclosures were incredibly high output enclosures which followed our mutual motto of, "It's not bass unless it produces 30Hz as loudly as 50Hz".
They actually did produce levels of 25-30Hz loudly enough to bring tears to one's eyes, set off car alarms across the parking lot, and cause an uncomfortable feeling in the ear unless one was wearing ear plugs, and did so with 6.5" woofers.
A high powered, large enclosure loaded with an high end 15" it was not, but most who heard these were amazed when afterward they saw 6.5" woofers, usually uttering the most often heard response of, "No way, I thought you had at least tens, if not twelves or a fifteen!"
In Johns VW Corrado, an early (and not yet perfected) Double Shot loaded with two Audiobahn 6.5s garnered 132.7dB at 31Hz on the new Termlab meter driven only by a single Soundstream D200 amplifier, while four beefy 8" placed 147.7dB @ 33Hz on that same meter in two 8" Double Shot enclosures in the rear of a VW Golf, driven by one MTX 1000w amp, no electrical mods to either vehicle.
They weren't designed with SPL in mind, nor solely with SQ in mind, but both. We called them SQL enclosures for 'Sound Quality - Loud'.
- Bad grammar, but accurate.
The videos with the odd looking enclosures were not in any way faked, and were using an enclosure design of mine which I asked John NOT to make public, hence the hush hush regarding those.
However that was the design upon which both the SS & DS were loosely based, and was included for the purpose of showing the possibility of getting truly sub-frequencies from such a diminutive woofer.
I once asked John if I could use a Snail Shell he had built for someone who called and ordered it for a Fosgate 12" but then called back and changed the order to one for a DD 12".
I saw him put the enclosure up into the overhead warehouse storage and hating to see waste I asked, "Hey John, how about I buy that and use my ID Max 12 in it"?
He said, "NO WAY! It's not designed for it and I don't want my name on something which won't perform correctly".
An honorable man, John Nolte, and an amazing abstract genius with both a talent and a penchant for audio, among other mechanical & scientific pursuits.
In his home he is currently listening to two 6.5" Double Shot enclosures, each with a two-way 360° midrange disperser on top below it's tweeter, which he built as prototypes.
Each enclosure has it's own 150w sub amp and he keeps them set on 3/10 or it would have seriously detrimental effects on the dinnerware, animals and fish which reside in the house.
Too bad not everyone can hear these shake his home.
On Enya's album Watermark, the song The Long Ships has a 27Hz note. When he plays that at a medium listening level I can see his glass sliding doors flex enough to warrant sitting well away from them and while doing so if I watch the woofer cones I see they are barely moving, an efficient enclosure design to say the least, with only four 6.5" EU-700 woofers & 300w.
Maybe John will one day begin making a few more for special orders, but for now he's had his fun in car audio and has moved well into home audio.
- Again, and for posterity, there is nothing faked in any of those now long-gone videos, and instead of buttering each other's bread about all the imagined reasons you have for belittling those truly incredible enclosures, would you have had the opportunity to actually experience hearing & feeling one you'd instead be debating all the possible reasons for why they do work so well.
Oh well, time marches on.
An externally hosted image should be here but it was not working when we last tested it.
Good On Ya'
Thanks for bumping up this old thread.
I know how people tend to mistakenly think others are like themselves so I can't blame you for your last comment.
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