Everything you need to know about PORT TUNING in under 3 minutes!

[@elfuego4341]

The DIY Audio Guy dropping knowledge once again.

[@DIYAudioGuy]

That seems to be my thing.

[@Jaden-up3bg]

Es El Fuego no?

[@magyandrade6787]

I am still don't know what is better hight tuning or low tuneing. I just need the best tuneing that has more bass.

[@exislaamnowbeinganinsaanah3302]

@@DIYAudioGuy I want very Low frequency at 10" subwoofer for earth shaking Bass. So what dimensions should be used to tune for deeper low Bass like earth shaking Bass? Please suggest me Sir... Thank you🙏

[@smokinschannel5840]

@@DIYAudioGuy not sure if you will see this or not but in about a month I am going to start building a 6th order 2/1 for 4 zvx 12's they are all going to share a 12qft ported internal volume and will be tuned to 30hz (i will call this the back of the box) the front half of the 6th order will be 6qft and tuned to 60hz but I am unsure how to tune the front does it tune the same way as the back? For example if my port need to be 12in long to achieve 60hz for the back half would my port need to be 6in long for 60 hz in the front si ce the front is half the volume of the back?

[@davebutler3905]

Brilliant video. You cover the basics clearly and quickly. Thank you!

[@DIYAudioGuy]

Thanks

[@JacobBennett45]

thank you for keeping it short and sweet

[@itsamadmadworld7524]

All the years I tried to understand this then I see this video. AWESOME 👌 🆒️ 🙌 👌 😎

[@DIYAudioGuy]

Thanks

[@-IE_it_yourself]

what is the alpha beta and gamma values defined as in the equation then?

[@amdomag]

There are other two variables are shown in the formula you posted - alpha and beta. Any idea on how to get the corresponding values? Any book/reference that you can suggest? Very informative video here. Please keep on posting.

[@SAMZIRRA]

this was awesome incredibly easy to understand description and I can’t thank you enough, especially my ears, they thank you the most. I took my pretty average Bluetooth speaker, and made a speaker box out of an ammunition box. Not only did it make the sound quality better, but it sounds so much louder and it is really fun to walk down the street with it because people don’t know where the sound is coming from it first and then get a very confused look on their face.

[@DIYAudioGuy]

That sounds like fun.

[@MR-he4jb]

Under 3 minutes 👌🤟✌👍👏 Thank you kind sir, no time for long videos

[@DIYAudioGuy]

Absolutely

[@waylon32411]

Thank you for the easy to digest information! 👏

[@DIYAudioGuy]

Thanks for watching.

[@ajmann07]

As always very informative and your presentation is SPOT on Young man

[@DIYAudioGuy]

I am bald and I have a gray beard, so I don't think of myself as young. But I guess I am younger than some people.

[@smartdevilevil]

@@DIYAudioGuy you have no idea how much you are helping people. Good man.! 👍

[@InsaneCajunsUnleash]

Excellent information & just what i needed. Thanks for DIY Man!

[@DIYAudioGuy]

No problem 👍

[@johnm.gerard1718]

I bought a Wuzhi 2.1 AMP from Amazon and a Dayton Audio 4" Mid Sub speaker. I have a corrugated tube from my paint spray booth just to try. If I place the tube over the top of my speaker and totally cover the cone the volume of air from the speaker is amazingly high. And the base is very high as well. I find from this midrange speaker that tuning the frequency down does not sound as rich but I am using the speaker as a sub/midrange speaker so tuning it up to hear more of the voice/music sound better. I bet I could use 2 in midrange and maybe one 5 1/4" as a sub range might sound better. I am just experimenting at this point. Also my tube has a rubber flang piece for connecting two pieces together. I have tried this as a temporary Baffle and as the base of the port tube. The rubber piece does seem to help the sound. As ca Baffle The rubber piece does add to the base that is coming out the bottom. Not sure if that is the effect one wants in a speaker. I wonder if this technique is better or worse that just placing a tube inside an inclosed box? Besides vibrating the tube I would think you would want as much air pressure coming out of the tube as possible. And there is a lot of air pressure in my design.

[@audfrknaveen2256]

You are simply awesome !!!! Thanks a lot from India !!! 😃😃😃

[@DIYAudioGuy]

You are to kind!

[@samueldevaney6675]

Great video, but what do I use for the alpha and beta values in the equation?

[@DIYAudioGuy]

I have it written down somewhere -- I will follow up with you when I find it.

[@apexdisease6030]

Dang, it must be in the back of the garage somewhere😂

[@-IE_it_yourself]

@@DIYAudioGuy really dude?

[@johnj2496]

Great video My only complaint is that I did watch it sooner but I can change the round port fairly easily unfortunately I have to make the port smaller

[@linandy1]

You can tune a port but you can't tune a fish.

[@ReallyConcerned]

Lol Daaaaad!!

[@ArcadeDude44]

Awesome info, thank you! Good stuff, as always.

[@DIYAudioGuy]

Glad you enjoyed it!

[@budgetaudiophile6048]

I'm all about huge enclosures for my home theater. My front stage has two 13CF dual 18 enclosures tuned to 15Hz, an 8.3CF dual 18 sealed enclosure and two 8CF sealed enclosures each with their own 18. Then out back I have a 128 cubic foot, near IB, with 6 18s in it. Bigger is better, HAHAHA! Well at least for my tastes in my theater. Response clean down to 7Hz. Definitely subscribing to this channel!

[@DIYAudioGuy]

It takes space to make bass.

[@budgetaudiophile6048]

@@DIYAudioGuy So true, my man! And the room plays such a huge part as well! With my theater setup the way it is, because my room is 1200 square feet, I still struggle to get much response below 7 or 8 Hertz or so (when compared to my 10Hz+ content). My mini-theater in our master bedroom, a 16Wx16Lx12H room, Has 4 15s in it and, at least according to REW and my SPL meter, is capable of getting pretty close to the same responses! I've been learning so much every day. I'm hoping I can pick up some more tips now that I'm subscribed to your channel.

[@DIYAudioGuy]

@@budgetaudiophile6048 sounds to me like you know what you're doing! I think I should be washing your channel.

[@budgetaudiophile6048]

​@@DIYAudioGuy HAHA! No way, brother! You're the one with all the knowledge. I just ask all the questions! I was looking to port my 128CF enclosure, at 15Hz, which is what brought me to your channel. I have a 5" x 85" port but I think even if I divide it up into 6 or 8 pieces (cut appropriately for port tune) that I'd still get WAY ABOVE port velocity. Here's the thing that's getting me wondering, though: My theater, as I mentioned, is very large! The face of the Smol Boi is nearly 30 feet away from my seating position! I was wondering if, given the other subs, given the dramatic output, would I still hear port noise from that far away. Not sure if you have the time to discuss that with me, but I'd love to learn more!

[@DIYAudioGuy]

@@budgetaudiophile6048 I honestly don't know.

[@doublemanson]

I understand that 33hz is the sweet spot and hip hop music rarely go much lower than that, but what is the lowest a person should ever tune their box to before running into problems (i have a 15" kicker L7s in a 6.8cu ft ported box)

[@DIYAudioGuy]

As you tune it lower, for the same size enclosure, the box will be less efficient. So think about it as the trade-off between low versus loud. Also keep in mind that in a vehicle you're going to get some cabin gain that's going to help fill in those low notes.

[@heathatkins2837]

The info in ur vids is epic! You got a new subscriber

[@akeshikenchi1886]

Very informative... Thanks... May request how other types of baffles like wbox, mcv boxes are tuned to?

[@DIYAudioGuy]

I'm not familiar with those alignments. Can you tell me more about them?

[@EazyBuildz]

Question when you say box volume at the end of the video Is it your net internal volume or the overall volume of the box WxHxD ?

[@BobGeogeo]

Very infrmative and concise. Many thanks. Did I miss the link to the port tuning calculator?

[@DIYAudioGuy]

In the description

[@BobGeogeo]

@@DIYAudioGuy Oh, Patreon only, missed that.

[@georgem6359]

Hi. I have liked all of the videos from you . Got a couple of questions 1-What is better - tune port to higher frequency or to a lower one than the fs? 2-if able to tune below the fs, how much lower, 5,10 or 15hz lower than fs? Keep up the amazing box building! Thanks for all the tips.

[@DIYAudioGuy]

We are doing a Q and A session on our live show tonight. I will answer the question this evening. kzbin.infoVCpaaVaU8-Y?feature=share

[@georgem6359]

Hi. Thanks for the answer in tonight’s Q&A session min 40. Just finished watching it. I get your answer but I think to fail to give more detail to my question (didn’t want to overwhelm) If the tuning is below the Fs, I see that the Cone Excursion going overboard. How much can the speaker go above the Cone Excursion red line (mm) in WinSD, if at all? If I leave the tuning above the Fs, it remains below the red line, but it’s not deep bass. When I set it below the Fs, the speaker does go above the red line. How much can I push above the red line (at my own rick), 1.0 mm ? The ratio volume box and excursion go hand by hand. Thanks again.

[@georgem6359]

Hi. Thanks for the answer in tonight’s Q&A session min 40. Just finished watching it. I get your answer but I think to fail to give more detail to my question (didn’t want to overwhelm) If the tuning is below the Fs, I see that the Cone Excursion going overboard. How much can the speaker go above the Cone Excursion red line (mm) in WinSD, if at all? If I leave the tuning above the Fs, it remains below the red line, but it’s not deep bass. When I set it below the Fs, the speaker does go above the red line. How much can I push above the red line (at my own rick), 1.0 mm ? The ratio volume box and excursion go hand by hand. Thanks again.@@DIYAudioGuy

[@thethirdman225]

I want to build some speakers with a front slot port, using an existing design. I naturally assumed that the port area and length would be the deciding factors. Then someone pointed out that a round port is generally more efficient because of thinks like boundary layer, Reynolds numbers, etc. (my Dad was a civil engineer). So how can I adapt a round port to a slot port?. (Still chuckling at your "Freedom units" comment!)..

[@bryanCLXT]

Thank you good sir for the content looking forward to more content and seeing you in the. kicker chat the polarity chat and all basshead chats

[@DIYAudioGuy]

I try to listen in on all of them, at the very least pop in and say high. It's hard to work all day, then come home, build, film, edit and still catch all the live streams. It seems like there's one every night!

[@bryanCLXT]

@@DIYAudioGuy I appreciate the time you take I've been wanting to put out content myself but YT always has something good so I'll just hang

[@DIYAudioGuy]

@@bryanCLXT My biggest regret is not starting sooner. Jump on Amazon and grab a $15 mini tripod and find some inexpensive editing software. Throw in 50 or 60 bucks worth of lights and you will be ready to roll. Start small, start simple, and have reasonable expectations.

[@lakeit]

Hi.. redoing by old 17 year old SUV... My Brother in law used to do this all the time and I gave him the internal dimensions I'm using.. and ge gave me port specs.. no idea what it's tunes to.. but, when I was 17.. basically 20 years ago.. for my birthday, he built a box that was awesome.. he has some sheet he goes off of.. So backstory over.. you mentioned.. ports can be used out of almost anything.. the tubes I need apparently are a 2x9" and a 6x4" diameter. Don't have them laying around but if I'm in DIY mode.. found 2 things that could work. does the material matter? plastic vs metal.. etc.. enjoyed your vid.. just made me have questions

[@faysalusman]

Is it a good idea to have lower box tuning say 20-25hz and have woofer which has a fs of 30-35hz to be installed in this box? Is this practical for HT setup. ? Couldn’t find this answer in YT videos. :(

[@DIYAudioGuy]

You can tune a box lower than the driver's Fs. That is how most home theater subs are tuned.

[@carl3820]

Thank you for the info. I am a little confused however. In this video you mention 3 things that can effect tuning. One being the vents cross sectional area. You said that with a larger vent cross sectional area it will raise your tuning, however in your other video labeled “understanding port length, box volume and tuning frequency” you show on winisd as well as mention that changing the vents cross section area has no effect on tuning. And those examples ranged from a 1” to 2” to 3” wide port changing the vents cross sectional area rather reasonably. Am I missing something? Thank you.✌️

[@carl3820]

That’s my fault. I had to rewatch the video. It seems The only reason the cross sectional area of the port didn’t make a difference in tuning when you increased the sizes was because you extended the ports length to keep tuning the same. So it would have raised tuning had you not lengthened the port. My apologies. I watched them too quickly. Plus you were talking a little fast towards the end of that video lol. Thank you again for the information. ✌️

[@DIYAudioGuy]

It's all good, if you missed it then others did as well. I will try to be a bit more clear and slow down a little. I tend to talk fast when I get excited!

[@thebreakbarrelshow]

Quick question, i normally build vented boxes with round ports but my next build will be square ports. I see some boxes with flares and some without.. would flaring always be a slightly better port design over non flared ports or would that strictly dependent on specific driver tuning ? Thanks in advance

[@mattstarke7373]

Flaring the ports will help keep the port turbulance down.

[@thebreakbarrelshow]

@@mattstarke7373 Thanks Matt

[@silverlining682]

Hi Diy Guy,is it beneficial to wrap sound deading around a plastic port?

[@DIYAudioGuy]

I have never tried that. I could not hurt.

[@MrRicman0101]

I think I love you, so much knowledge, so comprehensive, subscribed asf

[@tlewis3083]

I have a question that I have never heard a definitive answer on. I have been building and installing car / wakeboard boat audio systems for about 22 years now. My builds obviously change based on the customers expectations, customers music preferences, the amount of space their vehicle has and their budget. My next build will be for my daily driver Ford Focus ST. I plan on experimenting with the enclosure I build for it. Many people that decide to install a stereo system have seen vehicles with multiple subwoofers and they assume that running two subs vs 1 actually doubles the low end output. They believe bigger and more is better. They think they need to run 10,000 Watts and as many subwoofers as they can cram into a car to make bass. Many times my goal is to prove amplifier power and number of subwoofers has nothing to do with performance. It is funny. it always shocks people when I explain the actual volume difference between running 1 or 2 subwoofers in properly built boxes doesn't double the bass output. When I explain to them it only provides them a few DB increase in bass output by adding another subwoofer they look at me like I'm crazy :-). If one speaker puts out sound then obviously two we'll double that sound 😊 It's hard for people to grasp that the subwoofer is not outputting sound it's moving air which creates waves that we feel and hear. I try to convince them using single subwoofer in an enclosure that is built and tuned properly should sound amazing and provide very good bass output. Usually I have them sit in my 2011 F-150 running a single DC Audio M3 8 and they realize I'm not scamming them. Here is my question for you. Would building a dual chamber ported enclosure that has one smaller chamber (1cuft) ported somewhere around 40-50 Hz and then building the second enclosure larger (2cuft) ported to somewhere around 27Hz provide stronger performance across a wider frequency range than it would If I built a separate two chamber enclosure with identical sized chambers ported to identical frequencies? Is there a benefit compared to two identical chambers or would this be counterproductive? FYI The subs would be typical fourth order and both chambers will use identical subs. Most enclosures I build I attempt to tune them to have a flat response. In my mind it seems like two different tunings and enclosure sizes would allow me to tune the larger chamber to that same flat response allow that sub to play all types of music and then the smaller higher tuned chamber would give me very strong 40-160hz (snare, kick drums, lower mid-based frequencies). Technically wouldn't it provide better overlap with the mid-range / mid bass?. We've all heard car audio systems that have very strong bass with great vocals and high end but completely missing the crack of mid base that we all hear and feel at concerts. Obviously this is just a hypothetical question. I understand that the performance depends on the subwoofer parameters and how its performance is estimated in WinISD. Let's assume I did my research and have found a decent 10inch subwoofer that functions well in anywhere from .75 ft³ all the way up to 2.5 ft³.

[@ChristopherFrancisco-c4s]

Please help me, i want to build a box for 200 watts subwoofer, the problem is i really don't know the size to make a good bass sound, i want soft bass, please reply

[@mattgraham4340]

​@@ChristopherFrancisco-c4snot sure what you mean by soft bass, it's easy to make a speaker quieter. I'm sure there are any number of forums that would help you.

[@thomaslove6494]

​@@ChristopherFrancisco-c4s did you build your box?

[@RedCan_Rick]

Annother great video. That spreadsheet looks pretty handy.

[@DIYAudioGuy]

Yep, I have been building out tools like that so I can work faster. Less time planning means more time cutting.

[@richardalvis4695]

The thought being bass tubes do a thing. Boxes, with their 90 degrees bounce around frequencies. Pyramids would funnel right? And they are stackable 180 degrees out.

[@oisess]

If i have a sub its 16 square inches of port size. If i use 4 subs. Do i multiply it by 4?

[@NicksLife69]

I dont have winisd, but I have 4 skar sdr8 dual 4ohm in 2.25cf box and have the wrong port size with no idea what to do

[@gabrielpascual3046]

Nice explanation, so i could say that in port tuning frequency and frequencies just above, when the box is doing max spl ,,, in other hand, the subwoofer is taking the less power of the amp ? Or actually around this tuning frequency the sub is taking a lot of power from the amp? Thats my question

[@DIYAudioGuy]

I am not sure. I am not aware of anyone that has tested it.

[@Thor777AHT]

whats the benifit of larger and longer port over a smaller and shorter port? larger and longer ports = louder to a certain point? I have built full TL qarter wave for 12" bms bass and it was more deep bass than i could ask for, the woofer behaved like it played in free air almost so it was important for me to have a good amp to have control handling. Keep in mind i used foam stuffing on the walls of the ports so rid myself of unwanted frequencies if there was some.

[@DIYAudioGuy]

You need a larger Port opening so that you don't get chuffing, when you make the port opening larger you have to make the port longer.

[@Thor777AHT]

@@DIYAudioGuy Yes i know that. Im wondering about the pros and cons of larger vs smaller given that the port is not to small so that it makes fart sounds or so large it becomes a horn. yes the larger the port the longer it has to be to have the same tuning. but is there a benefit to having a long large one compared to a smaller short one that does not fart? i get that the pro of a smaller one is that is takes up less space. I guess the bigger one will give more db gain?

[@rl4416]

another great one.

[@JeffAdairKTM530]

Very good video. Thank you

[@DIYAudioGuy]

Thanks for watching!

[@freshram192]

I have 2 10" subs under my backseat in my truck in a non ported box, my question is if I put those 2 subs in a ported box would it hit harder with the same settings on the amp

[@DIYAudioGuy]

Yes, but you will need a bigger box, so it probably will not fit under the back seat.

[@freshram192]

@@DIYAudioGuy yes I was figuring on that. Thank you very much

[@FuhKai]

I’m trying to tune a right trapezoid slot port, is there a formula or program for this? My idea was to calculate the port area of the trapezoid and use a rectangle with the same port area in a slot port calculator, hopefully it works out, if you have any tips or ideas it would help tons!

[@DIYAudioGuy]

I don't know the proper way to proceed in this case. I have a few guesses, but since I am not sure I am not going to speculate.

[@FuhKai]

@@DIYAudioGuy no worries, hopefully it turns out well! If not I’ll be doing a aero port to simplify lol

[@MAD450r2]

I have a 3 cubic foot box for a 1990s Pyle 15 inch sub. the box is sealed. I'd like to port it for a bit more from it. would just a 4 inch tube work and how long would I need it to be to tuned to 32hz or about.

[@DIYAudioGuy]

Just adding a port to an existing box does not always work. I recommend using something like WinISD. kzbin.info/www/bejne/r4uxlox4jqyFgc0

[@shawnmcclure7282]

Im trying to figure out if I should port my underseat dual 10 box with 2 10" kendwood exfelon db+ 10s

[@DIYAudioGuy]

It's really hard to get an effective port in an under seat enclosure.

[@sonnyinaz]

I'm building a box. I had a friend who was awesome coming up with sizes shapes, porting and all that stuff. I did the wood working. Lost my friend, winisd always errors out or tells me i'm leaving something out so I never get the info i need for making the ports. Could use some help. The box is made from 3/4" birch. outer dimensions are 58" x 14" 12" deep. I'm putting 4 Fosgate P2D4 8" subs in it. needing port size and length to tune. Thx..

[@DIYAudioGuy]

bit.ly/48OVJGI

[@kevinfoster2308]

So if an enclosure has multiple identical ports should you add the cross section areas together and keep the lengths the same? Is there a way to break two big ports down to four achieve the same tune?

[@DIYAudioGuy]

No, when you add multiple points with the same cross-section the ports will have to be longer.

[@manitobamanitoba1796]

For example....if I have 2 sundown x18v3 subs....tuning at 32 hertz....can I get away with 3 6 inch ports at 11.56 inches long to have less port space taken up in the box....or is four 6 inch ports at 16.87 inches long better ?? Does it matter?

[@DIYAudioGuy]

You need a big port cross section or you will get chuffing. Four 6" round ports may be good for just one of those.

[@gordonhood5902]

Can i force a 8" subwoofer to produce lows? I found a box 32hz for dual 8's but will they sound good? i recently made a mistake on a single 8" 33hz box and it had little output but in a 41hz box it was decently loud the sub i used was NVX VCW84 Version 3 (VCW84v3) So now i've gone and made some expensive mistakes is it possible to make 8's hit them lows lol?

[@DIYAudioGuy]

You can tune it low but it will not be as loud, that is the trade-off.

[@mackemacchiato3238]

I have asked several comment sections if the ports volume is added to the calculated box volume or not…. Sune the port can swallow alot of volume from a subwoofer 🔊

[@DIYAudioGuy]

The net volume of The enclosure does not include the space taken up by the port. Vb in all of these, formulas is the net volume of the box.

[@Petethebuilder]

You explained more than most videos I have seen, also can you please make a video about a question I have. So my question is if my sub box is smaller than required can i compensate the missing cu.ft. with a bigger port or in other words lower tuning frequency.

[@DIYAudioGuy]

You can do that, but it will only get you so far. To make matters worse as the port gets longer it takes up more space in the box, reducing the box volume even more. In this video I show you the response function for a severely undersized enclosure, that's what you can expect to happen. kzbin.info/www/bejne/Y6rSoYekmrhqnZo

[@Petethebuilder]

@@DIYAudioGuy thanks👍👍

[@miltonwaddams3969]

I was wondering what source you got those two equations from? I can't seem to find them published anywhere else

[@DIYAudioGuy]

jlaudio.zendesk.com/hc/en-us/articles/221068047-Enclosure-Ports

[@-IE_it_yourself]

@@DIYAudioGuy that should be in your description

[@demetrius3d]

A question: If I'm using an isobaric loading of drivers that allows use of a box half the normal size, should I tune the port for the effective size of the box (X) or the actual size of the box (X/2)?

[@DIYAudioGuy]

Actual size.

[@PatrickTemme]

I am planning on building a bluetooth portable full range 8 order bandpass. The plan is to use a 4" 70Hz-20kHz speaker. I have some port questions if you can please help. TiA

[@DIYAudioGuy]

Those parameters are a bit complicated. Some websites list them for square porch, some for round ports. I had done the numbers to convert from one to the other but I can't seem to find the notebook where I did that math. By going this video was just to show people how the variables interacted.

[@PatrickTemme]

@DIYAudioGuy , please DM me if you could. Would love to pick your brain. I'm a R&D mechanical design and have some ideas that would be fun to talk about.

[@isaacramirez3729]

so the port is tuned to the box, right? If I change out the driver, it shouldn't have an impact on the port's efficiency, am I correct?

[@DIYAudioGuy]

Yes, but different drivers will sound different in the same enclosure.

[@iang7523]

Can some explain the measurements that are being used 12.03” 15.59” for subwoofer boxes

[@DIYAudioGuy]

I usually just round to the nearest 1/8th of an inch.

[@jordonmayfield6185]

I am curious to know. I have a 2.47 cu ft box with 9.6" LONG 4" AERO Port. It sounds good but why do I see some enclosure builds similar in size with what appears to be considerably longer ports with the same tuning frequency. Any chance you could tell me at what legnth I could extend the port to get the same 33hz tuning

[@DIYAudioGuy]

You will need to make the port wider if you want to make it longer and keep the same tuning frequency.

[@msh6865]

Round vs Slot ports....is one better? Is one better for SPL and the other for SQ? Enquiring minds want to know!

[@DIYAudioGuy]

Sounds like a good idea for a video!

[@roberttriner6242]

Yes, there can be quite a substantial difference between wide or “slot” style port when compared to a circular port opening/exit. The amount of difference relies on many factors. For brievity, I’ll focus on the most obvious factors. When it comes to slotted style vents, you’ll want to look at the following: 1) port depth/tuning length 2) vent opening height (probably the reason this venting style was chosen is to save a significant amount on this dimension when building an enclosure). 3) port width (probably the most critical). The reason that port width plays the biggest difference when compared to constant circular vent opening is due mainly to the change in air speed (and associated distortions) across a wider exit dimension when compared to the tighter circular path equivalent. This wider dimension allows for the air to slow disproportionately to the air exiting near the ends of the vent. Anytime there is an offset/imbalance of speed, volume, or pressure within a rapidly moving column of air; distortions or vortices will occur. Remember, this volume of air is trying to change direction 180*deg as fast as several hundred times per second! Even though laminar flow could never really be achieved in either design (or any acoustic resonator above ‘maybe’ 4Hz), It’s best to ensure such distortions be minimized for best overall performance. But again, it truly depends on many different factors, as well as the application of said design and the intended purpose (some designs benefit from a nasty whistling port... like most bandpass designs aka hemholtz resonators. And some applications could benefit from such distortion.... like dubstep playback for 2000 of your friends. Sorry for the lack of useful details on this topic, but a response to a KZbin comment really isn’t the ideal forum for such writing. There are some great things called books that will provide the answers that you seek. Cheers! -Rob

[@kristopherdonaldson9569]

I have a question you might be able to help me with.. I built a 6.5(net)cu.ft. box with a 5.75x13.75" port(29.5" long).. for 2 15"subs. The subs are on the sides with the port directly in between. Box was supposed to be tuned @ 30hz, and after testing I decided to try tuning lower. So I slipped a baffle down the center of the port, which would have effectively created 2 separate enclosures.. both 3.25CF@28hz. BUT..I didn't run the center port baffle all the way out. It only goes ABOUT halfway up the port, and then let's the 2 ports converge into one large Port. What did that do to my tuning? Technically I lengthened the port, but split the first part in half.

[@DIYAudioGuy]

That's not really something I can troubleshoot in the KZbin comments.

[@lawr3nc3mann84]

4.4 Cft Single 15" in 2door tahoe. Any recommendations?

[@DIYAudioGuy]

Yes! Download WinISD. kzbin.info/www/bejne/r4uxlox4jqyFgc0

[@johnnycarter6196]

I am having a DIY curently now, and decided to do a 3.5cu/ft box, for x2 12 inch Kicker's L5 S12L5 4ohm 600w RMS with the port in the middle. The sub will be in boot, but facing the front of the car, as the car benefits from a sky port between the middle seats, so the sub port will be sitting exactly in the middle, getting all the pressure and bass inside the car. Will this be ok? Box volume? I am calculating port zise as per Kicker's website suggestion for 1 12 inch sub, and i added double port size for 2 kickers. Can you confirm?

[@DIYAudioGuy]

That works fine if the subs are in separate chambers. When you double the size of the box to add a second sub the port gets shorter, then when you double the port cross section the port has to get longer. My advice is to call Kicker tech support, they will walk you through it on the phone.

[@johnnycarter6196]

@@DIYAudioGuy Basically their wesite and my sub specs are saying (SPL/Deep Bass: 3.25 cu/ft; 3"x13.25" port opening; 14.5" port length). What are the correct measurements for x2 of them subs? Also if the port lengh is bigger then the box itself, should i create the port in an L shape until it reaches the specifications size? Let me know please.

[@Rolandatw0w]

Excel file please and great video !

[@onemoreboat]

What site can I go to download plans to build a home theater subwoofer for behind the couch that someone has already done all these calculations?

[@DIYAudioGuy]

@toidsdiyaudio

[@piccidance971]

What are alpha, beta and gamma values?

[@ayushprashar7576]

For 8 inch woofer bandpass enclosure dimensions for loud bass

[@tiggstah]

Can you make the port OUTSIDE the box? i am ubering but want to add a ten inch to just wake the system up a bit. seeing as how i need the trunk space i am custom making a fiberglass and wood box in the side corner of trunk behind the wheel well. this does not have very much space. can i extend, from the box, a port channel that runs back and forth between wall and trunk hinge?

[@DIYAudioGuy]

Yes. You can do that. The sound waves coming from the port and the driver are large enough that they don't have to be right next to each other. But, if I were you I would consider using a passive radiator instead. Kicker has some really good pre-loaded enclosures with passive radiators. amzn.to/3sOWbR7 Those are designed to be installed down firing and you can throw luggage on top of them.

[@tonywright1889]

I want to build an enclosure for a 18 skar zvx that will fit in the trunk of a 2012 lincoln mkz

[@herrtrigger7220]

8 cubic feet, one Stereo Integrity HT-18v3. How many 4 inch round ports and how long should they be for 25hz? SI will not respond, none of the online calculators agree they are from 4" to over 100". Any help?

[@herrtrigger7220]

If I donate $10 I still won't understand whatever PhD type physics/area formula's etc I'll see. Then I'll have to pay someone to translate it. I just want port length and how many ports for 4inch ports. Thanks!

[@DIYAudioGuy]

Each time you add a port all of the ports need to be longer. That is probably why you are getting so much variance in the port length. Since you are struggling with the math it sounds like you just need to pay somebody to design a box. I can do it, but my turn-around time is very slow, if interested fill out this form: forms.gle/iM8hPa3Hw1e3uHNw6 . CAF and Drew Jones (Basahaulic productions) may be able to do it faster.

[@nvrfollowb5]

Hi, is there a book to look up all the formulas in?

[@DIYAudioGuy]

JL audio has them on their website.

[@rockfordhx2768]

What if I have a pre fab ported box with a port right in the middle for 2 12s and the depth between the wall and the port itself is 12 inches I measured the port width itself and it’s only 6 inches wide I heard it’s supposed to be the same width and length as the port

[@DIYAudioGuy]

I am having trouble visualizing that.

[@Chromedome-ss6mg]

I just got some information that you want 16 cubic inches of port per 1 cubic foot of box space. But when I did the calculation it seems extremely small to me.

[@exislaamnowbeinganinsaanah3302]

I want very Low frequency at 10" subwoofer for earth shaking Bass. So what dimensions should be used for deeper Bass? Please suggest me... Thank you🙏

[@DIYAudioGuy]

There are too many factors to answer that accurately in the KZbin comments. Best bed is to download Win ISD and model it.kzbin.info/www/bejne/r4uxlox4jqyFgc0 But, having said that if you want to get really low, down below what a human being can hear, You're going to want more cone area and you're going to want a huge box. Consider an 18. I suppose that all depends on what you mean by low. If you're trying to play in the 30 Hertz range a 10 can work just fine.

[@exislaamnowbeinganinsaanah3302]

@@DIYAudioGuy yes Sir I fully agree with you... But I prefer 30 Hz low frequency Bass... And would like less then 30 Hz . I don't like loud Bass [Upper Bass] . So could you suggest me what size [ dimensions] of enclosure should I use for this type Bass? Please sir suggest me. i will always be grateful to you... 💐Thank you🙏

[@DIYAudioGuy]

@@exislaamnowbeinganinsaanah3302 That will all depend on the driver. I recommend this one: bit.ly/3dcZAjm from parts express. They have box and tuning recommendations on their website. If you have a specific subwoofer in mind I can model that for you and make a recommendation. My rates are available here: diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html

[@exislaamnowbeinganinsaanah3302]

@@DIYAudioGuy ok. I got it.

[@exislaamnowbeinganinsaanah3302]

@@DIYAudioGuy thanks for this information 🙏

[@bgone84]

Good job on the Informational videos.. quick question to pick your brain. I'm having an issue with my subs coming apart at the glue seam from cone to surround. 4 12s in a 8cu ft ported custom box tuned to 37hz with a single 7.5in x 6in round port. Is there a chance the port is too big and subs are not getting enough back pressure and too much excursion? I run them fairly hard close to the rms, but not over. Or maybe I need to ditch these subs.....

[@DIYAudioGuy]

Mechanical failure is usually the result of over excursion, that happens when you play below tuning frequency or your enclosure is too large. 8 ft³ for 4 12's doesn't seem too far off to me, it really will depend on the sub. If you're pounding away at those subs with a 20 hertz test tone at full tilt that might be your problem. The other possibility is that you just got a batch of subs with bad glue.

[@bgone84]

@@DIYAudioGuy ok cool. Pretty much the other option I came too. I set my subsonic filter higher fir safety.

[@donlankford4315]

??? I HAVE a sub box for 2 10s, the box fits under rear seat of a 01 dodge ram ext cab.. 2 kicker cvr10s . the sub box says .570 air space per speaker, the box is also un ported.. I can't download the program you mentioned.. I'm also using a boss pv3700 amp.. what size port should I use?? . I mostly listen to rock and country.. I appreciate any suggestions... ty

[@DIYAudioGuy]

It is nearly impossible to port one of those ram under-seat enclosures. Juice is not worth the squeeze.

[@donlankford4315]

@@DIYAudioGuy ok ty vm ..

[@jerrettarmstrong5859]

Can you help me with a few specs after I get all my information. I don't have the software for winisd but just need some port length and number of port questions.

[@DIYAudioGuy]

diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html

[@denverfan1974]

Will a 23hz box with a 15inch sub be tuned to low

[@DIYAudioGuy]

Depends on the subwoofer and the application. If it is a home theater subwoofer it will probably work, but that is not ideal in a car.

[@aaront2172]

my amp has a subsonic switch @25 hz my box is tuned at 35 hz is that good? Or should i change port. 15 inch elektra audio is the sub new on the market

[@DIYAudioGuy]

Yes, that would be just about right. I would recommend activating that filter.

[@aaront2172]

@@DIYAudioGuy ok man thanks your the best on youtube

[@victorchapa2789]

Hello, I am trying to figure out how to design a box for my pair of JL subs 13” W3V3, I have an epicenter and I listen to Spanish music 90% of the time. What should my box be tuned at to get crips sound, my current box in my car doesn’t sound to well with Spanish music only rap.

[@DIYAudioGuy]

First step is to experiment with the settings on the epicenter to get what you're looking for. After that I would recommend speaking to a local shop that has experience with the genre.

[@victorchapa2789]

@@DIYAudioGuy will do, I am still somewhat new, so most likely I’ll take it to a shop around me to see if they could get it build the my music preference. Thank you !

[@murrayshekelberg9754]

What dimensions would I need to get my tweeters to peak at 35hz?

[@DIYAudioGuy]

❓

[@BestUnderPressure]

Hello, I have an ignorant question. When you say you're tuning the box to a specific frequency, what does that mean? The speaker will play other frequencies so I don't quite understand that terminology.

[@DIYAudioGuy]

That is a great question. At the tuning frequency most of the sound is being produced by the port. You will typically get a peak in output around the tuning frequency, then as you play lower frequencies the output will drop off.

[@BestUnderPressure]

@@DIYAudioGuy Thanks for the response. By output, do you mean volume?

[@DIYAudioGuy]

@@BestUnderPressure Yes

[@SoXDYTB]

Where is the link to the port area calculator?

[@DIYAudioGuy]

It is no longer available to the general public, hit the patreon link in the description.

[@zoranche1]

Why some subwoofers have port in the back? Is there any difference or are the same?

[@DIYAudioGuy]

There is a lot of debate about the port location. In home audio if the port is on the rear of the enclosure port noise will be less audible. In a car you can sometimes "load" the port against a wall in the vehicle and it will be a little louder.

[@audfrknaveen2256]

In slot port, the box walls are acting as port walls too, and they extend longer than port. So some people say WINISD shows upto 30% longer port length than needed. How far this is real ?? Any suggestions on this please ???

[@DIYAudioGuy]

See my reply to your comment on the other video.

[@audfrknaveen2256]

@@DIYAudioGuy 😀😀I was not sure if you would check the comments. So I asked the same question in two videos. I'm so glad you answered !!!! 👍👍👍😊😊

[@Petethebuilder]

I have a question, if my box is 9.92 cu ft and I want to tune it to 32hz but my port could only be 2"w 13"H but how long will it be?

[@DIYAudioGuy]

You can use my port tuning calculator to figure that out. It is available as a digital download to my patrons.

[@Petethebuilder]

@@DIYAudioGuy I'm sorry I have my neighbor writing for me but if you could give me what I need I got no issues donating plus u been a big help. Please 50 100 it's no issue to me I just didn't want to pay the shop 700 to do what I could

[@DIYAudioGuy]

Ok, I saw the messages on Instagram, I did not make the connection until just now.

[@fully_retractable]

Been wanting to make better boxes for my 6x9 speakers that rattle around in the cargo area of my suv.

[@DIYAudioGuy]

I have had that exact problem!

[@nickvanelzen4630]

being a noob at car audio like me can be frustrating lol. I recently bought 12"sub and a ported box from a stereo shop (tuned to 35 hz and I believe 2cu.ft) and had them install it. Going from previously having a sealed sub to now a ported. The ported is definitely louder but I feel like I have lost some of the low bass, like 25-35 hz. I understand that ported has a steeper roll off below tuning freq, but I just feel like my setup is really loud from 40ish hz and up but everything lower by comparison is barely there. I also switched from a sedan to a hatchback. I just dont know if the lack of low end is because of the tuning freq, or maybe a lack of cabin gain in my particular vehicle, or the sub itself (kicker cvr 12, the brand that everyone on the internet seems to hate), or something else

[@DIYAudioGuy]

Try moving the sub around, point it in different locations and directions.

[@sinisterATX]

Try a different Sub maybe, also what’re you powering it with ?

[@conradcamilleri9954]

Hi,can you help me to make subwoofer box on my boat?

[@DIYAudioGuy]

diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html

[@kaleberens6607]

I have 2 15 inch subs I want to tune at 33 hertz. I’m not sure how to figure out how wide and the length I need for a port

[@DIYAudioGuy]

I would recommend using WinISD. That way you can check for port air speed. kzbin.info/www/bejne/r4uxlox4jqyFgc0

[@carlthornton3076]

Very Good!..

[@DIYAudioGuy]

Thanks!

[@homelessdrifter9508]

but how do i know how large the vent opening should be

[@whiteXT]

I had to sub after watch this sub box tuning stuff. It's just very helpful that someone has done this.

[@DIYAudioGuy]

Welcome to the channel!

[@LacerationAudioPinoy]

Is it true that the port shouldn't be 3 times longer than it's diameter so it won't create port noise?

[@DIYAudioGuy]

Never heard that one. A lot of really bad rules of thumb like that are based in reality. 1) If your port opening is too small you run the risk of creating audible turbulence coming from the port. This port noise is often called chuffing. This is entirely based on airspeed velocity and has nothing to do with any particular ratio of port cross area to port length. 2) The actual physical port itself has its own resonate frequency. As it gets longer this resonant frequency gets lower. Typically it's not a problem for subwoofers because your crossover is going to keep your subwoofer from ever playing those frequencies. Plus, the port will become impractically long before this becomes a problem. For a situation like that you want to use a passive radiator. kzbin.info/www/bejne/rGXVcp6umNBllbM

[@JJSideshowBob]

I've tried to simulate Paul Carmody's DIY "Speedster" in WINISD, which is tuned to 55 Hz in a 5.5 l enclosure and claims to have a mid 40-ish F3. So I have entered the T/S parameters for the Tang Band W4-1720 chassis, measurements for the box and vent. Indeed I do get a very nice and flat frequency response curve but at -3dB, I'm still well above 50 Hz! The drop-off is much steeper than it should be, according to the info on the build. Where is that magic happening? Crossover? Dampening? Incorrect data on my end? WINISD isn't detecting any TSP errors for what it's worth. 🤔

[@DIYAudioGuy]

Odd. I would suggest that you head over to toidsdiyaudio.com and sign up for the forums. The guys over there are really helpful at troubleshooting this kind of thing. But my first guess is that tang band updated the driver and therefore the TS specs of change.

[@JJSideshowBob]

@@DIYAudioGuy Thanks, I'll do that right away!

[@The96hardbody]

I need help building a 4th order with external port

[@DIYAudioGuy]

diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html

[@djangusroundstone316]

I have a question about your formula, it is only for 1 and 2 subs. What if I have 4?

[@DIYAudioGuy]

There's nothing in the formula about the number of subwoofers, that's because you don't tune the subwoofers you tune the enclosure.

[@djangusroundstone316]

@@DIYAudioGuy okay. I just see the formulas and they have 1 sub and 2 subs so I thought that might factor into the formula somehow. Thank you for clarifying.

[@Two_chair_Lynn]

what about port loading?

[@DIYAudioGuy]

The math for that is a good bit trickier!

[@Jab_2023]

how do you know if the port is too big for the box?

[@DIYAudioGuy]

As the port opening gets larger the port has to get longer, it's too big when it can't fit in the box anymore.

[@abelscaliber7969]

I built my first box and I think I tuned to too low I was aiming for 32hz I think I hit 25 hz because it’s boomy at that frequency 😞

[@DIYAudioGuy]

Might be due to cabin gain.

[@baileyhelfinstine4194]

its not in the description

[@The96hardbody]

Link to Port calculator have the formula but still can't make sense of it

[@DIYAudioGuy]

To get access to the port tuning calculator all you need to do is support the channel on Patreon. $10 members get digital access to all speaker plans and spreadsheets: www.patreon.com/DIYAudioGuy

[@VoltzIsSalty]

I have a question I’ve been thinking about since I built my system. I made a dual 12 box about 5 cubic feet with a front center port that is T shaped about 20 inches long. Basically making it so each sub is in its own chamber and they “share” the port that in the middle. Does this mean It is setup as 2 separate enclosures each with a port length of about 20 inches, or does it count as an entire box with a single port like I originally thought. The tuning frequency should be about 30hz, and it seems so when playing the system but i’m wondering on how this is supposed to work, as if it is 2 separate boxes then wouldn’t the tuning be around 45hz?

[@DIYAudioGuy]

To be honest I am not 100% certain. An easy test would be to aim the subs up, put some rice (ro skittles, or whatever floats your boat) on the cone. Then play test tones at low volume, start at 25 hz and work your way up. The cone, and thus the rice, will not move much at the port tuning frequency. Or you can get a DATS: kzbin.info/www/bejne/bJiWaoaZjNKUabc

[@DIYAudioGuy]

The more I think about this the more I think I'm just going to have to build a box and test it.

[@VoltzIsSalty]

@@DIYAudioGuy The come excursion seems to be quite low at about 30hz so i’m fairly certain that is the tuning. The subs I have are 2 Skar Audio EVL-12s. The Xmax is about 23mm and they definitely get moving when getting down to the teens and up into the 40s. I am still confused and wondering though as to why the box behaves this way instead of acting like 2 separate enclosures with a higher tuning. If you would like me to share the design I came up with for my enclosure I would be happy to.