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more accurate, louder

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=90179
Printed Date: April 26, 2024 at 5:08 AM


Topic: more accurate, louder

Posted By: jmelton86
Subject: more accurate, louder
Date Posted: February 07, 2007 at 6:28 PM

I have come to a conclusion that sealed boxes are the way to go. But if you are not getting enough output from your sealed box, try this. Get some 4x4 pieces of wood. Put the box, speakers facing down, on the 4x4 blocks, of course you want to secure them together. Also what I did was screw a piece of 1' thick plywood to the front slot, as to direct the air to the rear of the vehicle. This creates a bass- reflex type effect. You get the accuracy of sealed boxes yet the output of bass-reflex designs. Now as for tuning- your on your own! All I know is that it hits alot lower, alot louder, while being very accurate. Also you still retain the high-powering capabilities of sealed designs.



Replies:

Posted By: stevdart
Date Posted: February 07, 2007 at 11:27 PM
  • "This creates a bass- reflex type effect."

Where is the Helmholtz resonator?

  • "Now as for tuning- your on your own!"

Tuning what?  It's a sealed enclosure.  There's no resonator.

It's a sealed enclosure... downfiring.  Period.  You just got a different response in your application than what you had before.  Experimenting with firing direction is a good idea in any vehicle; but before using a downfiring direction, consult a sag calculator to be sure that there are no long-term negative consequences resulting from having the driver in this position.



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: blackmica3
Date Posted: February 07, 2007 at 11:49 PM
stevdart, couldn't this possibly duplicate a slot loaded effect?




Posted By: jmelton86
Date Posted: February 07, 2007 at 11:51 PM
I did the sag calculator for both of my subs, yes I'm poor so I have 2 different kinds, and neither of them is down-fire-worthy. Which way could I face them to get the same output? What is a Helmholtz resonator? thanks




Posted By: stevdart
Date Posted: February 08, 2007 at 12:40 AM

Interesting:  historical note found in https://www.diracdelta.co.uk/science/source/h/e/helmholtz%20resonator/source.html

"The Romans used helmholtz resonators formed from clay urns to tune the acoustic characteristics of ampitheatres."

https://en.wikipedia.org/wiki/Helmholtz_resonance

blackmica3, the driver is damped by a sealed enclosure and is providing sound through the driver only.  There is no additional resonance and output source as there is with either round or slot porting.  Confining the square inches of airspace in front of the driver doesn't equate with adding a resonator.

jmelton86, best results are most often found by firing toward the rear of the vehicle, and actually fairly close to the rear.  But every situation, system and car is different...so if you can move the sub(s) in different directions and test with a SPL meter you can find the most output.  Finding best quality sound is easier...you only have to sit in the driver's seat and listen.

The port, whether it's a plastic or PVC round or whether it's MDF slotted, is a resonator.  The principle of "tuning an enclosure" by manipulation of air mass and neck opening (diameter) of a port is derived from the discoveries of Helmholtz (who you can read about in the Google search).



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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.




Posted By: aznboi3644
Date Posted: February 08, 2007 at 5:30 PM
Helmholtz Resonator is basically a ported box in lamens term...you can tell you friends that you built a Helmholtz Resonator for your sub to sound smart




Posted By: haemphyst
Date Posted: February 08, 2007 at 5:47 PM
aznboi3644 wrote:

Helmholtz Resonator is basically a ported box in lamens term...you can tell you friends that you built a Helmholtz Resonator for your sub to sound smart

Actually, "ported box" is the laymen's term for Helmholtz Resonator, HOWEVER, he has not built a Helmholtz Resonator. He has built a "down-firing sealed enclosure, with intimate-boundary acoustic reinforcement". Nothing special at all. It's a down firing, corner loaded sub. Move along, people, nothing more to see here!

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: aznboi3644
Date Posted: February 08, 2007 at 8:12 PM
haemphyst wrote:

aznboi3644 wrote:

Helmholtz Resonator is basically a ported box in lamens term...you can tell you friends that you built a Helmholtz Resonator for your sub to sound smart

Actually, "ported box" is the laymen's term for Helmholtz Resonator, HOWEVER, he has not built a Helmholtz Resonator. He has built a "down-firing sealed enclosure, with intimate-boundary acoustic reinforcement". Nothing special at all. It's a down firing, corner loaded sub. Move along, people, nothing more to see here!


That is what I meant...that the HR is a ported box, in lamen's terms...sorry about forgetting the comma lol




Posted By: haemphyst
Date Posted: February 08, 2007 at 9:13 PM
Just jabbin' at ya... but you still have it backwards. The ported box is the layman's term for Helmholtz Resonator. Helmholz Resonator is not the layman's term for ported box... You said it backwards both times. posted_image

You know I have to poke the bear! posted_image Take it as the joke it's meant ot be, please...

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It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."




Posted By: aznboi3644
Date Posted: February 08, 2007 at 10:55 PM
damnit haem...That is what I mean haha...I know you're just being a smartass haha

Damnit now that I look back at it yeah i do have it bass ackwards lol...damn you





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