Darren69 Posted May 15, 2017 Share Posted May 15, 2017 (edited) Ladeezangennelman (TM Mr Smith, RIP) My gorgeous speakers have 210mm long 90mm ports behind the woofers, top and bottom (Dapplolito layout). Woofers enclosures are around 500mm high by 330W x 430 D, woofers are Vifa M26WR-09 more info in this post- Regarding the ports, would I gain any benefit by adding some internal flares? I have never seen straight porting like this. I would need to get some 100mm and sleeve them down to 90mm somehow. I have checked some porting formulae and glazed over almost instantly, haha. Or just try it out and see? Edited May 15, 2017 by Darren69 Link to comment Share on other sites More sharing options...
Weka Posted May 15, 2017 Share Posted May 15, 2017 Easiest way is to buy some flared port tubes of the same diameter and retrofit them. I've always been a fan of having a brace panel with flared opening terminating the inside end of the port as well to provide better loading. 1 Link to comment Share on other sites More sharing options...
LogicprObe Posted May 15, 2017 Share Posted May 15, 2017 Port flaring is to reduce 'chuffing' at high volumes. (like the sound of someone playing the jug) The length of the port determines the tuning. (formula can be found on the net) 1 Link to comment Share on other sites More sharing options...
Darren69 Posted May 15, 2017 Author Share Posted May 15, 2017 6 minutes ago, Weka said: Easiest way is to buy some flared port tubes of the same diameter and retrofit them. I've always been a fan of having a brace panel with flared opening terminating the inside end of the port as well to provide better loading. Canna find any 90mm stuff. what do you mean by brace panel? Link to comment Share on other sites More sharing options...
Weka Posted May 15, 2017 Share Posted May 15, 2017 8 minutes ago, Darren69 said: Canna find any 90mm stuff. Get the next available size and recalculate the required length for the same tuning. what do you mean by brace panel? A ~300mm x 20mm panel between the cabinet side walls with a radiused entry in the centre to the inside port end. 1 Link to comment Share on other sites More sharing options...
LogicprObe Posted May 15, 2017 Share Posted May 15, 2017 (edited) Plenty of 90mm around! http://www.vinidex.com.au/products/pvc-stormwater/ 100mm to 90mm adapter https://www.bunnings.com.au/holman-100mmx90mm-pvc-storm-internal-pipe-adaptor_p4770444 Edited May 15, 2017 by LogicprObe Link to comment Share on other sites More sharing options...
tubularbells Posted May 15, 2017 Share Posted May 15, 2017 Hey Daz if its to reduce port chuffing try the old ProAc trick and jam in a tightly bunched handful of drinking straws into the ports (cut to the same length as the port). This was also a trick often employed by Trevor Lees with his speaker designs and works surprisingly well. You could also easily experiment with leaving the straws longer to see if that helps. 1 Link to comment Share on other sites More sharing options...
Darren69 Posted May 15, 2017 Author Share Posted May 15, 2017 9 hours ago, LogicprObe said: Plenty of 90mm around! http://www.vinidex.com.au/products/pvc-stormwater/ 100mm to 90mm adapter https://www.bunnings.com.au/holman-100mmx90mm-pvc-storm-internal-pipe-adaptor_p4770444 Yes LP if I couldn't find actual 90mm flares then the PVC adapter was the next option along with a 100mm flare. Thanks Brah. @Tubularbells a port cat-converter? Haven't had a good listen at big SPL yet to hear if there is chuffing, I was more wondering if there might be a bass improvement with the flaring. 1 Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 15, 2017 Share Posted May 15, 2017 11 hours ago, Darren69 said: Regarding the ports, would I gain any benefit by adding some internal flares? You'll change the tuning of the ports ..... so unless you are comfortable with that (ie. you can measure the tuning to ensure it changes that way you want, or that you design the re-ort so it doesn't change) .... then don't do it. Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 15, 2017 Share Posted May 15, 2017 2 minutes ago, Darren69 said: Haven't had a good listen at big SPL yet to hear if there is chuffing, I was more wondering if there might be a bass improvement with the flaring. A flared port is a good idea ..... but the biggest thing you'll notice if you modify the port (unless the replacement is of exactly the same tuning as the old one) .... is the different tuning. It would be like asking "should I put slick tyres on my car" (cos they're"better") .... but the slicks we're planning to put on are substantially different sized wheels. It is the different sized wheel which will dominate the performance difference.... and the change in performance you notice, is not going to be very much to do with the "slick" unless the stars are really aligning. Link to comment Share on other sites More sharing options...
Guest rondine Posted May 15, 2017 Share Posted May 15, 2017 There was a paper from the technical people at Philips that I recall found less port noise from a non-flared port. Maybe JAES late 90's. ron Link to comment Share on other sites More sharing options...
Sub Sonic Posted May 15, 2017 Share Posted May 15, 2017 @Darren69 are the current ports causing chuffing at higher volume? If not, I'd be inclined to leave it as it is. If it ain't broke, don't fix it. Cheers, SS Link to comment Share on other sites More sharing options...
Darren69 Posted May 16, 2017 Author Share Posted May 16, 2017 59 minutes ago, Sub Sonic said: @Darren69 are the current ports causing chuffing at higher volume? If not, I'd be inclined to leave it as it is. If it ain't broke, don't fix it. Cheers, SS Will check it out once they are at the right height (am working on finishing off some plinths if the bloody conical spikes ever arrive). True (if it aint broke) but don't mind tweaking for improvement, so long as it can be undone if there is a sideways or backwards step. All sounds a bit technical though and that's usually a good way to put me off an idea, haha. 1 Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 16, 2017 Share Posted May 16, 2017 4 hours ago, rondine said: There was a paper from the technical people at Philips that I recall found less port noise from a non-flared port. Flaring a port helps lots ..... but the actual flare needs to be quite specific, and it's possible to "do a flare" which doesn't help much/any. Link to comment Share on other sites More sharing options...
Guest scumbag Posted May 19, 2017 Share Posted May 19, 2017 https://speakerbug.com.au/index.php?route=product/search&search=Port Anything here that might help? I do agree though, apart from aesthetic reasons, if you are not hearing chuffing from the ports, I'd be wondering if it is worthwhile changing them. Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 19, 2017 Share Posted May 19, 2017 IMHO it would be always worth better flaring a port .... just becuase you don't notice the problem, doesn't mean you won't notice the solution. .... but sticking flares on an existing port, will make lots of changes not just due to the flares (the changed tuning). .... so an apples to apples comparison is hard work. Link to comment Share on other sites More sharing options...
Upfront Posted May 19, 2017 Share Posted May 19, 2017 What about drinking straws in the ports to smooth out airflow?Sent from my SM-G900I using Tapatalk Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 19, 2017 Share Posted May 19, 2017 11 minutes ago, Upfront said: What about drinking straws in the ports to smooth out airflow? Becuase the straws will slow down the airflow (Adding resistance to the port) ... it may take away the 'chuffing', but it also takes away the output. Kinda like driving under 80 to avoid the road noise problem you have when driving faster than 80 ..... does that analogy even make sense?!? Too mcuh wine. 1 Link to comment Share on other sites More sharing options...
Upfront Posted May 19, 2017 Share Posted May 19, 2017 Becuase the straws will slow down the airflow (Adding resistance to the port) ... it may take away the 'chuffing', but it also takes away the output. Kinda like driving under 80 to avoid the road noise problem you have when driving faster than 80 ..... does that analogy even make sense?!? Too mcuh wine. Nope, got it. Straws take up that much space? Link to comment Share on other sites More sharing options...
davewantsmoore Posted May 19, 2017 Share Posted May 19, 2017 No, the air being forced through smaller holes, encounters more resistance than one big hole. 1 Link to comment Share on other sites More sharing options...
Darren69 Posted May 19, 2017 Author Share Posted May 19, 2017 I gave it a blast tonight and no 'chuffing'. I was wondering if the flares might improve bass further but will leave it alone. Link to comment Share on other sites More sharing options...
Pops110 Posted May 22, 2017 Share Posted May 22, 2017 Can't hear any chuffing through my ports, ( except after a big night on the curry ) The ports are flared on the front baffle but they are straight cut internally. They are 90mm but have been lined internally with the same felt / foamish material that is around the tweeters. Never seen that before. 1 Link to comment Share on other sites More sharing options...
Weka Posted May 22, 2017 Share Posted May 22, 2017 Lining the port with felt is done to minimize air turbulence by providing a resistance to the laminar air flow. Also, flared ports need to have quite a large radius of flare before they are in any way effective. 2 Link to comment Share on other sites More sharing options...
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