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Thomas Hosker
Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493 |
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Posted: 20 August 2016 at 11:21am |
Im wondering what would happen under a few different circumstances.
First one being a ported subwoofer enclosure with say 4 tube ports of 2 different sizes. Would the port tuning just average out across the 2 different port lengths? Also another scenario, If you have a "double tuned" rear chamber with the rear of the driver firing into a rear chamber ported into another chamber thats then ported to the outside. Is there any pros or cons to this? Im assuming it cant be simmed in hornresp but akabak? Im thinking the second scenario is what void use in the ported horn subs? |
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cookie-dj
Young Croc Joined: 09 May 2014 Location: Warwickshire Status: Offline Points: 977 |
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A previous thread here
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You can't polish a turd!
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Thomas Hosker
Registered User Joined: 20 June 2012 Location: East Sussex Status: Offline Points: 493 |
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Cheers dude, only really seems to mention the first scenario i posted. How about the effect of porting a rear chamber into another chamber and then to outside?
Although i noticed a video popped up on youtube the other day and was quickly removed detailing the insides of the Void Stasys X v2. That seems to be a straight up ported bandpass horn arrangement. Although i know the trinity x and other variants were like scenario 1. Hmmm |
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cookie-dj
Young Croc Joined: 09 May 2014 Location: Warwickshire Status: Offline Points: 977 |
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I remember there being a thread on here about someone that designed a bass horn with 2x different horn paths to achieve a wider frequency response.
I think the conclusion was that it wouldn't work well due to cancellations at the mouth. Not too sure about 2x different ports though |
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You can't polish a turd!
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White Noise
Registered User Joined: 05 January 2015 Status: Offline Points: 54 |
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Although i noticed a video popped up on youtube the other day and was quickly removed detailing the insides of the Void Stasys X v2. That seems to be a straight up ported bandpass horn arrangement. Although i know the trinity x and other variants were like scenario 1. Hmmm [/QUOTE] That video is still there dude, interesting, it does look like a bp6 with some kind of horn, i thought there would be more to it.... there must be, oherwise the port would be waay quieter than the horn ? unless it has a really narrow tuning band ? as for the scenario 2, if you havent already, have a look up on the bose acoustimass, some of those use a similar series tuned arrangement. Edited by White Noise - 22 August 2016 at 6:51am |
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Elliot Thompson
Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5172 |
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That would be the old Bose Acoustimass 5. The downfall of such a design is the limited frequency response. The frequency response is limited due to all the sound projecting through the ports. Best Regards, |
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Elliot Thompson
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White Noise
Registered User Joined: 05 January 2015 Status: Offline Points: 54 |
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Yes thats the one !
depending on how the tuning is used, the limited response could also be seen as a plus side too if you think about it, because its dictates a high and low roll off for the chamber... plus the multiple harmonics of the tunings must mean more gain within the bandwidth ? that's if i understand it correctly lol Edited by White Noise - 22 August 2016 at 7:21am |
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toastyghost
The 10,000 Points Club Joined: 09 January 2007 Location: Manchester Status: Offline Points: 10920 |
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That video is still there dude, interesting, it does look like a bp6 with some kind of horn, i thought there would be more to it.... there must be, oherwise the port would be waay quieter than the horn ? unless it has a really narrow tuning band ? as for the scenario 2, if you havent already, have a look up on the bose acoustimass, some of those use a similar series tuned arrangement. [/QUOTE] Defo not a BP6 - There's a lot you're missing in that video frankly, it's actually just two FLH sections with a bandpass tuned rear section that then ports. There are technically 5 chambers as per marketing, you just need to look for where the divides are. If anything the old Trinity was simpler. |
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Elliot Thompson
Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5172 |
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Such a design can compliment a loudspeaker system that can deliver bass on its own. However, if such a design is used solely as the primary source of bass, you will have an abundance of missing frequencies. The ports are not large enough achieve the upper bass region bass at a great amount of SPL. Having a large surface area plays a factor which, the ports cannot accommodate while, offering an extended bass response at the same time. Best Regards, |
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Elliot Thompson
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Kino
New Member Joined: 16 November 2016 Location: Leeds Status: Offline Points: 1 |
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Hi, The video seems confusing is it possible you could clear a few things up for me? so the rear of both the drivers are in one chamber what is the letterbox port looking bit to the left of each driver and when the videos goes down the horn path is the horn split in two or is it just bracing in front of the driver.
I remember reading an article where rog explains the stays x design where he states there is and intermediate chamber before porting to the outside but from this video it seems to be that the rears of the drivers are ported directly to the five ports on the front of the cab as the guy videoing it seems to have his arm down the port? i was under the impression it was a 6th order series band-pass design where i assumed a FLH infront of the driver and the rear chamber was ported into another empty chamber which was then ported to the outside. Im doing loudspeaker design for my final year project and was looking at doing a ported horn design hence my interest but understand if your reluctant to divulge any more information Thanks
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corell
Young Croc Joined: 19 August 2013 Location: Berlin Status: Offline Points: 1161 |
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It is technically an 8th order design. I wont go into detail but imagine a ported horn with another port going from the rearchamber into the hornpath.
You can simulate a serial tuned BR with hornresp. Use vtc as the 1st chamber, apt1 as the inner port, S1-S4 to form the second chamber and S4-S5 for the second port. Interesting results with low qts chassis! |
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mstep77
Registered User Joined: 19 July 2006 Status: Offline Points: 457 |
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