In short, yes. Because of the diameter is smaller, you need to cut the port shorter. I did some calculations and cutting it down to 3" or 75mm should do the job. What is the penalty for using a smaller diameter is that when the speaker is driven hard, then the peak velocity in the port goes up and potentially can become noisy. It comes down to how powerful your amplifier is and how loud you like it. For most of us, it is likely not to be a problem.
Woudn't 3 1/2" plumbing pipe work?
Pipe nominal size | Outside dimensions | Inside dimensions
3-1/2" 4.000 3.521
90mm = 3.54331
Also, is there any disadvantage to using a 4" flared port? I am sorry if this has already been asked.
Precision Port 4" Flared Speaker Cabinet Port Tube Kit
I have one on a speaker kit that I built and I never hear anything from the port.
If you can't find 3 1/2 in PVC pipe, maybe you can use a 3" coupling and grind the little wall in the middle out. The O/D on 3"
pipe is 3.5"
Edit: This is a repair coupling that is 3.5" inner diameter and has a length listed as 3.93" (100mm). My local HD has 24 in stock. Maybe this could work. You may have to paint it black though.
https://www.homedepot.com/p/Charlot...-Hub-Repair-Coupling-PVC001301000HD/203393300
Since the diameter is larger by 4mm, the length would have to be slightly longer. A nice detail would be to make a cutout on the inside of the panel and lengthen the port that way.
Let me know if this sounds like a good idea.
Pipe nominal size | Outside dimensions | Inside dimensions
3-1/2" 4.000 3.521
90mm = 3.54331
Also, is there any disadvantage to using a 4" flared port? I am sorry if this has already been asked.
Precision Port 4" Flared Speaker Cabinet Port Tube Kit
I have one on a speaker kit that I built and I never hear anything from the port.
If you can't find 3 1/2 in PVC pipe, maybe you can use a 3" coupling and grind the little wall in the middle out. The O/D on 3"
pipe is 3.5"
Edit: This is a repair coupling that is 3.5" inner diameter and has a length listed as 3.93" (100mm). My local HD has 24 in stock. Maybe this could work. You may have to paint it black though.
https://www.homedepot.com/p/Charlot...-Hub-Repair-Coupling-PVC001301000HD/203393300
Since the diameter is larger by 4mm, the length would have to be slightly longer. A nice detail would be to make a cutout on the inside of the panel and lengthen the port that way.
Let me know if this sounds like a good idea.
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Mikerodrig27,
I like the idea of the plumbing part --
Also, Parts Express offers a 3" port kit as well as that 4" kit...and according to their marketing tag line, "The unique flared-end construction of the Precision Port™ system enables it to outperform any standard port tube on the market. Conventional tubes suffer from nasty turbulence at the entrance and exit of the port, producing unwanted noise and poor sound quality."
Joe your thoughts? Hype or fact??? 3" or 4" or just a straight plumbing pipe repair fitting from our local Home depot? Am I overthinking this?
Thanks
HappyJack
I like the idea of the plumbing part --
Also, Parts Express offers a 3" port kit as well as that 4" kit...and according to their marketing tag line, "The unique flared-end construction of the Precision Port™ system enables it to outperform any standard port tube on the market. Conventional tubes suffer from nasty turbulence at the entrance and exit of the port, producing unwanted noise and poor sound quality."
Joe your thoughts? Hype or fact??? 3" or 4" or just a straight plumbing pipe repair fitting from our local Home depot? Am I overthinking this?
Thanks
HappyJack
Also, a Big Thanks Joe -- I got my package yesterday, opened it and found some well packed, really nice waveguides and Crossover boards. They left your area 9/2/2021 and arrived at my house 9/18/2021 -- just a little over 2 weeks in spite of COVID-19 restrictions and slow-downs. Thanks again. Now I'm awaiting the rest of the crossover parts from Hi Fi Collective. Then the work begins.
HappyJack
HappyJack
Do they have any more. I would buy a truckload at that price.
Thanks Joe - very useful, looking forward to further posts.
Also, I don't think the repair fitting has a center stop. Maybe you could find it in SCH-80 dark grey
Bravo, I got mine the same day I'm in Florida! (For a Hamlet build). Happy I sent you a PM and I can speak to the ports. I sent you the link to the ports I used, and I do NOT hear any noise from the ones I used. I used the 3 3/4 I can verify if you want, and cut them to the appropriate length!
Also, I didn't say this in the PM, just thought of it, I have a friend in Jacksonville NC, I live in Jacksonville Florida now. He a HUGE Audiophile, and I'm hoping to bring my Hamlets up there for an audition. Maybe I could make it your way too..but this is obviously down the road....way down the road.
Incidentally...I used these not sure which diameter,
Speaker Cabinet Port Tube 2" ID Adjustable
I cut the hole to the I.D. of the port and used a round over router bit, and screwed the port to the inside. Troels Graveson has some info on rounding over the inside of a port...let me just say...I do paint and body for a living and I have worked on at least thousands of plastic bumper covers, if not tens of thousands, and it didn't work for me. That doesn't mean it won't work....just not for me.
But I haven't really noticed any port noise from my Elsinores, but I used I believe the flared 3 3/4" ports from P.E.
Speaker Cabinet Port Tube 2" ID Adjustable
I cut the hole to the I.D. of the port and used a round over router bit, and screwed the port to the inside. Troels Graveson has some info on rounding over the inside of a port...let me just say...I do paint and body for a living and I have worked on at least thousands of plastic bumper covers, if not tens of thousands, and it didn't work for me. That doesn't mean it won't work....just not for me.
But I haven't really noticed any port noise from my Elsinores, but I used I believe the flared 3 3/4" ports from P.E.
Folks:
Here is the port that I used in my Elsinore build: 2pcs Subwoofer Port Tube Bass Vent For 12"/15"/18" Speaker DIY Repair 110x200mm | eBay
I have no complaints about them.
Regards,
Scott
Here is the port that I used in my Elsinore build: 2pcs Subwoofer Port Tube Bass Vent For 12"/15"/18" Speaker DIY Repair 110x200mm | eBay
I have no complaints about them.
Regards,
Scott
Crossovers
I got my "care package" containing 2 ea black crossover boards from Joe a couple of weeks ago.
Yesterday I got all of the crossover components I need to complete the crossovers for the Elsinores -- from HIFI Cooperative in UK -- received 2 days after the package was shipped. Amazing delivery speed during this time of COVID shutdowns!!
It took about a month from the time I ordered the parts to the time HIFI Coop was able to gather them all up and ship them out. But I got everything I needed from one source (and only had to pay 1 shipping bill)
I plan to complete the crossovers next week and set them aside.
Next step after that is to start on the speaker cabinets.
By the way, it's really good that these crossover boards are robust enough to hold all of the inductors -- the boards are going to be pretty heavy once loaded up with components...
(sorry about the sideways picture -- Apple iPhone picture opened in Preview got saved to my desktop in the incorrect orientation...and I can't figure out how to delete it from the preview post and reattach it to this post???)
HappyJack
I got my "care package" containing 2 ea black crossover boards from Joe a couple of weeks ago.
Yesterday I got all of the crossover components I need to complete the crossovers for the Elsinores -- from HIFI Cooperative in UK -- received 2 days after the package was shipped. Amazing delivery speed during this time of COVID shutdowns!!
It took about a month from the time I ordered the parts to the time HIFI Coop was able to gather them all up and ship them out. But I got everything I needed from one source (and only had to pay 1 shipping bill)
I plan to complete the crossovers next week and set them aside.
Next step after that is to start on the speaker cabinets.
By the way, it's really good that these crossover boards are robust enough to hold all of the inductors -- the boards are going to be pretty heavy once loaded up with components...
(sorry about the sideways picture -- Apple iPhone picture opened in Preview got saved to my desktop in the incorrect orientation...and I can't figure out how to delete it from the preview post and reattach it to this post???)
HappyJack
Attachments
L1
Joe,
With reference to the parts list in post 4060, you emphasize the importance of L2, C1 and R1. What about L1?
Your recommendation for L1 is an iron core coil with discs. Those have a reputation for stronger bass below 200Hz or so - was this a material consideration, or do you have other reasons for not recommending to get the best one can afford for L1? Thanks.
Joe,
With reference to the parts list in post 4060, you emphasize the importance of L2, C1 and R1. What about L1?
Your recommendation for L1 is an iron core coil with discs. Those have a reputation for stronger bass below 200Hz or so - was this a material consideration, or do you have other reasons for not recommending to get the best one can afford for L1? Thanks.
I appreciate the inquiry - I have thought about it. Quite a bit actually.
L1 is still important and maybe I should have added that too, just not quite as important. It is that awkward in-between and also there is size consideration while keeping DC resistance reasonably low, so I have been using the Jantzen 3.9mH 000-5013 and can recommend it. The DCR is very low at 0.28 Ω and actually a bit lower than it needs to be. I would have minded it being a bit higher at 0.5 Ω would still have been acceptable and if in P core style, a little smaller.
The fact that this is not air-cored would make it very large and I want it to fit on the PCB. Finally, the 'leg' here is nominally 16 Ohm because the two 8 Ohm drivers are in series. Considering the high sensitivity of the Elsinores, compared to a 4 Ohm speaker with lower sensitivity, well you can see that the core is less likely to cause a problem and especially if of decent quality. An 85dB sensitivity and impedance that drops below 4 Ohm and the amplifier having supply a LOT more current? Yes, that becomes important. BTW, I have made this comment before.
Of course, these are only recommendations, this is DIY. But a commercial build of the Elsinores using the Jantzen choice would work. But commercial and DIY is different. We can do as we please... almost.
Cheers, Joe
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Yes, the Behringer B300 is a vented box actually having four ports. Found some flexible wash-balls like shown in the photo. The larger 8cm diameter ones seem to work better with enclosures this size, and 60 were used to fill about two thirds of the box using a screen to prevent the balls from getting into the bass drivers. This replacing the original stuffing results in open sound and depth imaging. Much more clear and relaxing!
The idea was to breakup internal box resonances creating minimum load on the woofer. I thing the amp will possibly run cooler due to better ventilation.
Attachments
Cabinet drawing Fusion 360
Using this project as an inspiration to get a working knowledge of fusion 360. I think I am at a point where I can share it for some feedback.
Here are the points where it differs from the Original:
An interactive view of the box can be found here You can view it 360, explode view it, cross section analyze, measure it etc [Note Link may only be available for ~30 days]
How much does nominal thickness vs actual thickness impact speaker cabinet design spec tolerances?
I wonder what somebody local would charge to get it CNC router cut, if we provide the fusion file?
Thanks
Using this project as an inspiration to get a working knowledge of fusion 360. I think I am at a point where I can share it for some feedback.
Here are the points where it differs from the Original:
- All panel are 18mm (3/4" stock more common than 1"); keeping the ext. dimensions the same; result int. volume will be slightly different. I am assuming the diff is not enough to warrant any Xover/port changes.
- Includes a Rabbet/Dado design (started more so as a way to learn and test parametric modeling; I suppose it also helps aligning the cabinet for assembly/gluing, does it add strength/stiffness to the end product?)
- Did not include port/slot for connection terminal/wiring harness. (leave it as end user's choice [Terminal plate, speakON, etc])
- 5mm radius on all corners of the finished box.
An interactive view of the box can be found here You can view it 360, explode view it, cross section analyze, measure it etc [Note Link may only be available for ~30 days]
How much does nominal thickness vs actual thickness impact speaker cabinet design spec tolerances?
I wonder what somebody local would charge to get it CNC router cut, if we provide the fusion file?
Thanks
Attachments
Thank you for the response. Yes you are right, design is simple enough to not require any fancy machine and efforts on finding better material may be the way to go.
To clarify : I meant CNC router table to cut all the panels, assembly ready, in one go from a 4'x8' sheet and a file. A sheet can be MDF/PLY/Composite/any better material one may choose.
Thanks
To clarify : I meant CNC router table to cut all the panels, assembly ready, in one go from a 4'x8' sheet and a file. A sheet can be MDF/PLY/Composite/any better material one may choose.
Thanks
Looks nice! The advantages of the rabbets are it limits the amount of edge grain that you have to deal with while also strength to the joints. I suspect the extra strength in the joints isn't really necessary. However, the edge-grain being limited really does help the finish work.
I also like how the top panel doesn't have any edged showing.
I also like how the top panel doesn't have any edged showing.