Understanding Port Length, Box Volume, and Tuning Frequency.

[@st170ish]

Excellent very informative!

[@DIYAudioGuy]

Glad it was helpful!

[@mariatori2374]

@@DIYAudioGuy hello sir can I ask for your suggestion box for a Groundzero GZIW 12 SPL to make it hit lower bass.

[@ashleymalone5396]

THIS is where I need to expand my knowledge. Good info.

[@DIYAudioGuy]

You're just aren't a lot of videos out there that explain this.

[@BabyCharlotteschannel]

@@DIYAudioGuy yeah for sure. We all know that there are Lot's of SPL guys hitting one note at their peak but aside from that stuff I haven't seen much about finding a nice low tuned box with a reasonably sized port area to keep port noise to a minimum. God willing I can sell something or get a good side job that'll enable me to buy this nice custom box with a level 4 DC Audio 12" sub included with it. ,* Thinking about doing something similar to my last car audio build with a 12" in a better box than last time, and a 15" in bigger & lower tuned box then at least one set of decent 6x9's in those little sealed boxes plus the fairly good speakers already in the factory locations for mids and highs. *Too bad I didn't have a really good way I can think of to mount the 6x9's in something bigger cause I've seen some amazing sounding 6x9's mounted in the back deck of a Ford escort hatchback and even some mounted in the rear deck with the trunk as the enclosure.. I just might have to build some slightly larger sealed boxes for them maybe on each side of the rear seat of my first generation Grand Cherokee I just picked up. Guess it all depends on if I can make the Extra approximately $300 for everything from the 12" and custom box, a Little package deal with a couple of good full range amps and a box with dual 10"s I believe etc, and then the pair of 6x9's for some nice and solid mids and highs.. getting most of this stuff used, plus still having some things I just couldn't include with the car and system I sold my Buddy!!

[@td2791]

I'm about to build my first enclosure for a SQL-12. Your explanations and use of WinISD is exceptionally helpful. Thank you for explaining so clearly, it makes me less nervous about building my own.

[@DIYAudioGuy]

Glad it was helpful!

[@FireMedic312]

I used this video and 2-3 others to build me a dual vented, dual 12” enclosure. First slot vent I ever built and it is superb. Winisd came in clutch.

[@DIYAudioGuy]

Great to hear!

[@gordythecreator]

Your explaining exactly what I've been HEARING for years now. I didn't want to figure out the formula for myself, and I assumed someone had already done that

[@DIYAudioGuy]

That's cool!

[@mikewhite4541]

Fantastic video. Best one I've found explaining the difference. I've built alot of boxes and had to just learn by trials and errors. This is badass.

[@preston2078]

I've watched this video like 6 times while making my first box. Thank you

[@DIYAudioGuy]

Glad to be of help.

[@sveneisenhauer1]

Ah, finally a tutorial that puts this into better perspective. Thanks! Now, please also build the boxes and show us and you’ll have friends forever...! 🤗😇

[@DIYAudioGuy]

That is definitely in the works! Just waiting on the time and the money to do it. In the meantime: kzbin.info/www/bejne/mpO5lWifnMidftU

[@seanyounk1]

Holy moly. My head is about to explode! I'm going back to your oscilliscope video to make sure I am doing this correctly so I don't damage anything. Thank you again for all the incredible information.

[@DIYAudioGuy]

Glad to help.

[@ReferenceFidelityComponents]

A few things: turbulence occurs well below 18m/s, more like 11m/s. Size of port may not influence transfer function in CAD but the realty us that it will increase impedance coupling efficiency with the room air mass which is beneficial. Rule of thumb is to use a port area approx 30% of the area of the driver. You loose port efficiency and alter system Q by using folded line ports compared with port tubes with or without elbows but straight vents are fine. Experienced designers know that box calculators over simplify the expertise needed to maximise SQ, system efficiency and to more accurately design and tune a vented system which ideally also includes system impedance testing.

[@drywater_]

I remember spending months teaching myself this stuff back in highschool. Wish you were around back then lol

[@DIYAudioGuy]

I was around, I was just not making videos.

[@feedrate1]

Love all the hard work you put in to your channel. Definitely one of my favorite channels!!🤘🤘🤘

[@ganeshkc1397]

One of the best explanation in one of the most simplest words .. Thank you so much

[@DIYAudioGuy]

Glad it was helpful!

[@jmjm003]

Years ago (90s) when I had a Fiero our local audio shop placed a JL Audio 10" in the front trunk and vented it through the passenger side floor. The way this video starts kind of makes sense to me now how they did it. It was a very custom job back then and might even be considered so today. To look in the front trunk all you would see is a box as the sub was inside firing into the port area.

[@DIYAudioGuy]

That sounds like a bandpass.

[@Bassotronics]

Another thing to note is depending on where there port opening finishes (near the enclosure or far from the enclosure) will also affect tuning despite the length due to different frequencies having different wavelengths. Port location is also crucial to the overall frequency response. (Phasing).

[@DIYAudioGuy]

Yeah, there is a lot more to it! I need to build some boxes and take some measurements!

[@BabyCharlotteschannel]

I like that, very important. Probably equally as important as positioning of the sub, and port too I would think, i.e. sub parallel to the rear door of a minivan or SUV etc..

[@303nitzubishi4]

Excellent explanation. I have read up on velocity V excursion a couple times and vaguely understood it, but your presentation of the sketchups and graphs really solidify the principles in my mind. I am indebted to you sirr thank you:)

[@DIYAudioGuy]

You are welcome.

[@vikassm]

Me after this video: I KNOW KUNG FU!!

[@DIYAudioGuy]

🤣

[@daveanthonysalalima1128]

None sense.😢

[@christianolsson834]

Neo! 😂

[@rowlesorama]

Show me

[@authenticNL2]

​​@@rowlesorama This is a sparring program!

[@agghell224]

I was looking for a port explanation and i found it. New subscriber here !!!

[@shawnsanderson3695]

Got a lot out of this and right on time for my latest build. Thanks

[@DIYAudioGuy]

Glad I could help!

[@dennis3004psp]

Xmax is the reason why i go 3 or 6 db below the max this works very well and over 100db is a good trade off for sound quality

[@DIYAudioGuy]

👍👊

[@gkk2001]

Your videos are maybe the best for us DIYers. I tried WINISD and find it has a mind of its own. Entered sub data and it changed many entries, same units but a different number. Also have a serious conflict comparing 2 subs in the same box, one gives port velocity of 20+ while other is near 2. Could not bring them close after manipulating most sub T/S parameters. I really do not like WinISD despite its free. I got what I paid for.

[@DIYAudioGuy]

I hear you! I think I am about to outgrow WinISD. WinISD will auto-calculate parameters. It is always better to let WinISD do the calculations, or the driver integrity check will fail.

[@BabyCharlotteschannel]

It has it's limitations BUT, it's free and will DEFINITELY help with designing a better sounding box for the specific subwoofer you have! Those of us that are true audiophiles can always use more data AND real world testing. Moving whatever box around plays a huge part of it all along with the specific vehicle and the cabin gain and general acoustics too.. Hopefully I worded that properly.. lol, just waking up after a long sleep just recovering from the chi-flu so I'm not quite at a hundred percent yet..

[@SandersAmps]

Greeeeeeaaat video. I build some cabinets for the first time using ESI (extra spacial intuition - i.e. guesswork :) and found them to be surprisingly close to what I needed. Didn't take air velocity into account though. Or a bunch of other things. But your explanation helped me understand what I'd done, and how to tune them better. Thank you!

[@DIYAudioGuy]

Thanks!

[@AwestruckOffRoadingHertz]

Another excellent video, thanks for taking the time to explain this in terms pretty much anyone can understand. We are always learning!

[@DIYAudioGuy]

Glad it was helpful!

[@alanfarmer5730]

Theile & Small parameters are important for selecting drivers to design compact enclosures.

[@randomtoyotadude8952]

Love this video, watched it many times.. to make sure i understand this. Thx DIY dude ;)

[@DIYAudioGuy]

Glad it helped!

[@almetej29]

By far the best video ever on enclosures. Well done

[@DIYAudioGuy]

Thanks.

[@AussyOutlaw]

Oh man! I learned something new today! Thanks man!!

[@DIYAudioGuy]

Good!

[@mhnoni]

I've learned a lot from this channel, thank you so much.

[@gsxroyce256]

At the 5 min mark, where we see the sub over extending, if you move the tuning frequency up from 28 to 35, to put that dip where the sub don’t move much at the tuning frequency, would that eliminate over excursion on the 4qf box? Edit/ NM you answered that at the 8:15 mark. My bad I should’ve just kept watching lol

[@HighVybeTribe]

i have seen plenty of subwoofer box builds where the port is external . Matter of fact a 1 cu ft enclosure for a 10 " sub with a 3inch Aero port about 10 " long

[@DIYAudioGuy]

It's not a very common design, but it works..

[@dannypalmer7701]

My friend made a 4×4 Bass Box and you can hear his Bass coming mile away ! Thunder!!

[@RandoManFPV]

Laughing so hard at the types of answers I get when going to Google for audio info. I searched "is cold weather bad for your subs?" Here's what I found lol: *How do you warm up subs?* take the top off the sub, put the sub on some aluminum foil, turn your oven on broil, put your sub in the oven for like 3 minutes (just stay close by, you'll smell when it's done depending on how much stuff is on your sub), remove sub from oven, reconstruct, devour

[@DIYAudioGuy]

🤔🤣🤣🤣🤣

[@arnicus208]

I’ve watched numerous videos on this channel, and I definitely get the feeling he doesn’t like sealed enclosures

[@DIYAudioGuy]

They both have their place. I don't post a lot of videos about sealed enclosures because they are simple to design and build, and don't require a lot of technical knowledge.

[@randybaltimore4605]

Thanks alot, I'm starting to understand alot more !!

[@DIYAudioGuy]

Glad to help.

[@fz6rider072]

Thanks in advance for my previous question I built a box for two X8 V4 and I missed my mark, only by 0.1 on the net box volume, but I severely missed the Port length, it's tuned to about 25 hz I was shooting for around 33 hz, I can shorten the port but that makes me miss my 2 cube net box, end result will be close to 2.3 net 33 hz, Love the videos I learn a lot from your content

[@somekiwidude]

Damn this gets technical making my first ported box wish me luck

[@gsxroyce256]

I’ve always build my own boxes but never knowing what I doing lol. But always got lucky. I build a box for a single 18 evl Skar. It was 3qft with 8” round port that was 23” long and was 3” from the back of the box. It peaked sub at 50hz. I left it alone bc l don’t know what to do and it sound fine so it was what it was. It could’ve been a lot better now that I’ve seen this

[@fullsendmarinedarwin7244]

Group delay is important if sound quality so important to you. Ported will always have bigger GD than sealed but they can sound good if you spend the time with design software getting it dialed in

[@TheMichaelvolz]

I like to think of it with one of those pull whistles that you blow in and pull the bottom. The longer the vent / longer out you pull the whistle end, the lower the note. That's just to grasp the concept tho, nothing specific.

[@DIYAudioGuy]

I had never thought about that.

[@jpfaff777]

What an awesome video. Very informative. Thank you 🙏

[@DIYAudioGuy]

Glad you enjoyed it!

[@Cetrifuga1945]

Sono stanco di essere preso in giro da te e il tuo compare 🌇

[@andrewforsythe7240]

Excellent videos. Just discovered your channel, glad I did !! Thank you.

[@DIYAudioGuy]

Welcome to the party!

[@tristanboyle4450]

So I think the 3 years passed has probably changed the concept of the ‘too small’. The folding of the port is from my observations is really practical. Thanks for all the info, but every time you say ‘is very impracticle’ I think: no it’s very easy to fold the port in.

[@r3d-1truth17]

Thanks for all your hard work and detailed efforts! Great stuff, and supersized knowledge boosters! I want to know if you build boxes for sale? I really don’t think I have a shop in my city that does your calculated and measured technique and approach for boxes. And I really would like another tuned box for my next two cars audio systems.

[@DIYAudioGuy]

I don't. Mostly due to shipping costs.

[@Fernando.Canal2]

This is a trully masterclass

[@DIYAudioGuy]

Thanks!

[@MilesPrower69420]

im quite dyslexic and when i designned my box in some rando software for the net i accedentally set my speaker magnet volume to be a few cubic feet, my 1.5 sq ft box ended up being nearly a 4 foot box, i made 2, and boy howdy did it hit those lows hard, haha

[@Ritalie]

As a kind suggestion, I'd try getting a microphone with a built low frequency crossover filter, to block low frequencies, like an AKG P120 or something more expensive. This video has a lot of deep bass blips that come from the microphone when you're speaking.

[@DIYAudioGuy]

I upgraded to a shotgun with one of those filters. It had its own problems. I have switched to a lav mic and better editing software. Check out a recent video.

[@666hobart]

A minute and a half in and I'm reminded of Goldilocks & the Three Bears.

[@DIYAudioGuy]

Good one!

[@666hobart]

@@DIYAudioGuy Yea good vids, decent informed opinions. I like it. At least you're not throwing random drivers in random "kit boxes" disregarding T/S params like some home theater channels out there!

[@gavinlamp]

awesome work, great information.

[@chadputt116]

Oh yes you are the best. I watch this yet I have an odd question still. I have a couple of Sundown Audio subs. One is an E12v1 D2 ( I believe) and a E12v3 D4. The E13V1 I have a Kicker DX500.1 1 0hm amp and the E12v3 I have a DX500.1 2 Ohm amp and a Kicker CXA1200.1 2 Ohms. I have been running onr 12 inch subwoofer on and off for as long as I can remember I. I have always used sealed enclousres that I built myself. Fairly simple rectangle builds. Even with the sundown I started sealed and moved to slot ported. Ok...I built, well have cut out a box from Sundown's site that is 1.75 tuned to 32. The box has a single baffle and after all the cutting and fitting I have decided I would like to slap a second baffle if not for support the for looks. The sub and port both front or rear firing depending which you call front or back. Sub is offset about 3" inches off center next to a 2"slot port. My question is, if I add a a second baffle on the outside, not changing inner volume and the baffle will only effect one side of the 4 sided slot next to the sub. So it will be the long side of slot leaving 1 long and 2 short sides open. Will the box read that as I have changed the port length? Sorry for the long story...thank you.

[@DIYAudioGuy]

Yes, but it will not make a big difference. The port will be longer by 1/2 the thickness of your material.

[@rakkup7572]

Absurdly is absurdly subjective ✌🏼

[@DIYAudioGuy]

😀

[@ILKOSTFU]

Awesome, thanks a lot!👌

[@DIYAudioGuy]

Happy to help!

[@LGFoutdoors]

Port on my latest box build is 4.75” x15.5” x22.25” 2 15s tunes to 30.6 hz

[@DIYAudioGuy]

I bet the box is HUGE!

[@dannypalmer7701]

Keep the giant airflow in mind!

[@exislaamnowbeinganinsaanah3302]

Great! 👌You described properly .... Very informative 👍

[@DIYAudioGuy]

Glad you liked it.

[@exislaamnowbeinganinsaanah3302]

@@DIYAudioGuy 💐 🙏

[@josearias8433]

My confusion comes in when you squeeze the port into a box, youre bringing down the air space of the box, therefore, how do you really know what the port length should be when fitting it in a box? For example. A 4 cubic ft box is asking for a 9 inch port length for 30hz but once squeezed in the 4 cubic ft box, that is no longer 4 cubic ft and needs a different size port for the 30hz

[@DIYAudioGuy]

You just have to make the box bigger, the problem is that you often find yourself in a loop.

[@magnumcipher4971]

What impact does the use of an enclosure wall for the structure of a vent actually have on the effective vent length and subsequent enclosure tuning frequency? In my experience, it marginally but measurably lowers the effective tuning frequency where the total vent area is less than 12-15 square inches. Maybe I'm just splitting hairs..

[@DIYAudioGuy]

It makes the effective length of the port longer by the width of the port. So if you have a 3-in wide port, you need to make your port 3 in shorter in order to hit your tuning frequency.

[@draydentyrrell5134]

Helpful video! Thank you!

[@DIYAudioGuy]

You are welcome.

[@DNL82]

Nice information 👌, wish I wasn't so dumb so I could make use of this. 🤣😅

[@DIYAudioGuy]

I am confident that you can figure it out.

[@juanmartinvk]

Great video, thanks

[@DIYAudioGuy]

You're welcome!

[@evrenodabas6154]

hello i have cervin vega wmax 15.2 and i couldn't manage to make a box for it can you help me thank you so can you make me a box sizer

[@DIYAudioGuy]

I offer design services. diysubwoofer.blogspot.com/2021/05/custom-subwoofer-enclosure-designs.html I don't build boxes, the shipping cost is just too high.

[@hippo-potamus]

1:03 Ive wondered about ports that are that small. If you can have that 4cu volume would that port be good or would it act more like a leaky sealed box?

[@DIYAudioGuy]

I don't recommend the 4 CU FT box with the 1X12 slot port and a 10" subwoofer. It was meant to be a completely absurd example.

[@glennmorgan4197]

The other thing to take into consideration is that the larger side panels can resonate, especially at low frequency.

[@DIYAudioGuy]

I have been digging into that, trying to find a formula that will tell me when a wood panel of a given size will resonate. I have yet to crack the code.

[@turboduckhead6179]

What would happen if you take the 1ft cube box and make the vent "snake" on the outside of the box. Like a T Line box, add lots of 90 degree bends on the port, outside the box, to compact the overall length of the port and make the overall size of the box more compacted. I hope that makes sense.

[@DIYAudioGuy]

That works just fine, it's just a pain in the ass to design and build.

[@turboduckhead6179]

@@DIYAudioGuy Does the 90 degree bends have an effect on the airflow in the same way as 90 degree bends in a hydraulic system, or bending a wire 90 degrees will increase resistance?

[@DIYAudioGuy]

@@turboduckhead6179 to be perfectly honest, I don't know. It seems like it's done a lot and it seems like it would restrict airflow but I'm not aware of any testing or evidence to prove that it does or does not have an impact on the sound. If lumber prices ever fall I might have to build a box and test that out.

[@turboduckhead6179]

@@DIYAudioGuy I see prices of birch has tripiled in prices since corona..

[@DIYAudioGuy]

@@turboduckhead6179 fortunately lumber futures are beginning to fall. It's going to take a few months before that to translate down to retail prices.

[@pirotex2005]

Nice comparison 👍 informative

[@DIYAudioGuy]

Thanks!

[@realchronal]

genuinely helpful, +1 subscriber keep it up!

[@A6Legit]

Quality video

[@theinventionshow]

can you explain why you see some measurements on -3db what it show to us??

[@DIYAudioGuy]

Like at 2:10? That's the f3. It is a way of quantifying how low a subwoofer can play. There is not much output from the sub when it plays lower than the f3.

[@theinventionshow]

@@DIYAudioGuy thanks

[@DJCJ999]

Hey! So I need to make a custom sub enclosure to go under the back seats of my truck... How do I go about sizing a sub and tuning the enclosure? My starting point would be to make the custom box the max size possible.. from there I will know the cu3 capacity of the box.. with that information how do I then size a sub for that box?

[@joelthomas79]

Actually the first box is practical in a center mounted design on an Aventador. Between the two seats is roughly 12 inches, behind the seats is only 4”.

[@DIYAudioGuy]

Cool!

[@RydinginStyle72]

What about round flared plastic ports? Like say a 3in diameter tube with a flare that's 12 in Long in a 2ft cu box? So if you were to drill a couple 3 in Holes and add the flared plastic parts of a certain length? Would that work?

[@DIYAudioGuy]

Yes, flares are great, they reduce port noise

[@Bigislandguy]

Do you think it would matter if the sub is mounted center in an enclosure versus offset? Would it affect the spl or sq?

[@gtg-inspections]

Really interesting. Thanks for your explanation. Are conical ports a thing?

[@DIYAudioGuy]

Flared ports are conical.

[@travisgulley2652]

If you enlarged a 10 inch cutout hole on a 10 inch subwoofer enclosure to fit a 12 inch subwoofer into the enclosure would you suffocate the subwoofer itself or possibly block the vent on the back of the subwoofer itself if the subwoofer ends up getting mounted into the enclosure itself after enlarging the cutout hole.

[@DIYAudioGuy]

Cramming a 12 into a box design for a 10 is a bad idea.

[@reverbae]

Hey My Prefab Subwoofer Box Tuned At 35Hz Is It Good If Not How To Get It More Lower I Am New At This Please Help😊

[@DIYAudioGuy]

That is probably just fine, but it will depend on your subwoofer. If you are happy with the sound then don't change anything.

[@reverbae]

@@DIYAudioGuy i don't have Subwoofer i had woofer 8"

[@reverbae]

60w 8ohm

[@reverbae]

@@DIYAudioGuy but i wanna go more lower so tell me how to do that

[@travisgulley2652]

Do all qpower prefabricated subwoofer enclosures that are already assembled have screws holding them together.

[@DIYAudioGuy]

I'm not sure. I build all of my boxes with glue and Brad nails.

[@fz6rider072]

Quick question if I go to the 12 volt website port calculator and it asked me for the box volume and my tuning to find the length for the port is the box volume it's asking for net after subwoofer displacement or gross box volume?

[@doctorhaircut]

Does the shape of the box affect the tuning? I want to build a single 15" box at 3.5 Cubic ft but the dimensions I have seen online are too deep to fit in my vehicle. If I make I take an inch off the depth and make it an inch taller, would that affect a lot?

[@JoshM7]

Great video, would be cool If you talked about port resonance as well. I've never payed attention to it until a week ago after someone brought it up and I confirmed my 18 has a horrible noise at the resonance frequency. I've heard the noise in the past but didn't realize it was the port resonance frequency doing that. It's not an issue in my case as that's at 128Hz, but they were thinking of building a sub with it at 86Hz and we're thinking that'll sound horrible with that resonance frequency being in the area he wants to play. Heard the general rule of thumb with that is make sure it's an octave above where you want to play. Like if you want to play 80Hz and below, make sure it's not lower than 160Hz. I wonder if additional bracing would dampen it out, or build the box in a way to cancel it out using math and dimensions that line up with the frequency.

[@DIYAudioGuy]

I would have to do some research before I could give you a decent answer.

[@travisgulley2652]

If you were to plug up the port on a subwoofer enclosure with a giant cork to make it a sealed enclosure will the giant cork get blown out of the port if you crank up the volume really loud and if the subwoofer is getting a lot of power

[@DIYAudioGuy]

That depends on how tight the seal is. There are some home theater subwoofers that use this principle.

[@skidrows420]

What about a small box like the first one with mutliple ports?

[@obsessivegarage921]

Thank you

[@DIYAudioGuy]

Thank you.

[@hippo-potamus]

Can you have a port that while tuned low is so large that the subwoofers won't have enough force to move the air in and out of it? or is this not a consideration?

[@DIYAudioGuy]

At some point it becomes a poorly designed transmission line. You run into problems fitting the thing in a car, or to much hassle trying to fold the int to enclosure. Like the 5 ft long port at the end of the video.

[@HashDogg06]

In my experience having a big port gains efficiency & gains output on low power however going smaller can get louder but you need more power to do so, there are always trade-offs.

[@travisgulley2652]

Can a 10 inch cutout hole on a 10 inch subwoofer enclosure be enlarged to fit a 12 inch subwoofer if so will it be a tight fit for the subwoofer and cause the subwoofer to not sound the best.

[@DIYAudioGuy]

Yes, you can make the hole bigger, but 12's typically need more airspace than 10's to sound their best. So I don't recommend that you do that.

[@sdrtech]

Can you please explain why port length changes when you switch the height and width? Shouldnt it be the same since the vent area is the same

[@DIYAudioGuy]

If the vent cross section area is the same then the vent length should be the same.

[@sdrtech]

@@DIYAudioGuy i agree but the software doesnt lol.. Just make sure I wasnt losing my mind thanks

[@rajeshbridgelal8105]

when designing subwoofer enclosure does the external dimensions of the port in cubic ft have to be added to cubic of the box or just the internal volume of the port?

[@DIYAudioGuy]

Net volume is just the airspace alone. Gross volume will include the airspace, the port, all of the material used to make the box and the port, and the drivers.

[@gunlover7851]

Do you think its important to include the air volume into the displacement of the box? I have added the material volume for probably 15 years, but with playing with a new program it includes the air volume too. Love your input. The application is car audio heavy bass

[@DIYAudioGuy]

Not sure what you mean. If you mean the space that the subwoofer takes up and you absolutely need to include that.

[@gunlover7851]

@@DIYAudioGuy the air space in the port

[@DIYAudioGuy]

@@gunlover7851 The airspace in the pork is separate from the airspace in the enclosure. Most subwoofer enclosure calculators and software don't include the port in the airspace.

[@gunlover7851]

@@DIYAudioGuy thanks brother.

[@travisgulley2652]

Can you plug a big 15 inch high powered active subwoofer that has a plate amplifier with 1000 watts of power consumption into the 120 volt ac outlet on the back of a home theater receiver

[@DIYAudioGuy]

Probably not. It depends on the amp rating of the outlet.

[@bospurgeon1039]

I’m just grabbing at this video hoping the comments can still get a reply. Is there a general consensus on the use of bent ports? Like just a 90 with double flares?

[@DIYAudioGuy]

Sharp angles don't work well. You want a wide sweeping elbow like used for drain pipes.

[@iChubbs_81]

Great video boss

[@DIYAudioGuy]

Thanks!

[@travisgulley2652]

Can a old 12 inch guitar amplifier cabinet be used as a subwoofer enclosure for a 12 inch car subwoofer.

[@DIYAudioGuy]

That depends. If it's a bass then maybe yes. But normal guitar captain has an open back so that will not work. The other thing to remember is that the drivers use bass guitar amplifiers are just PA drivers. They're not tuned terribly low. Just eyeballing them in the guitar shop, they all seem to have very small and short ports. I'm guessing they're tuned around 40 hertz. So that will be fine if you're just going to play normal music, but if you're going to play a bunch of rebased or trap/edm you'll probably damage the driver.

[@RobertJeffersonBased]

I have a box I built that's 4.7 cu. Ft. Tuned at 26Hz with a 5x20 inch port for 100sq in. Port area. It has some T-line properties and peaks at 28Hz. Can't throw more than about 400 watts at the GW-124 walmart sub in it because of the volume, but it gets dumb low

[@subdynoman]

Sweet any pics or vids?

[@RobertJeffersonBased]

@@subdynoman yeah there's a little demo on my channel

[@JoePalmer-zp4wx]

I am in serious need of some help with my custom build. I have watched your video and so many others trying to tune my custom box in WinISD and just can not figure it out. now maybe its because I entered my driver information in incorrectly but it did show up green and allow me to move forward. so I just bought a Skar audio VXF 12" 2 ohm and it calls for a recommended 2 FT3 @ 33Hz in a ported box. I can get con excursion perfect and the transfer function magnitude perfect but I'm always way over air velocity. I'm over 10' of port or 8 flanged tubes @ over 8" each. I'm willing to donate or what ever it takes at this point to get the dimensions I need to process. Let me know if there's something I'm missing. Thanks!!!!

[@jasonmartinez7667]

Is it possible to make a 1.5 cubic feet box and tune at 32 for an 8 inch sub?

[@DIYAudioGuy]

Absolutely. In this video I show the formula and spreadsheet that I use to make my calculations. kzbin.info/www/bejne/i2algpeklsytjZo

[@Thumper68]

To large of a box causes over excursion for sure. I think lining the walls of the box with Poly fill can help with this some. I am going to probably test this today since I’m going to be building a box similar to box 2. For a 12” alpine. Calls for 1.75 cu ft for ported box but I think I’ll build around 2 cu ft to about 30-32 hz. Going in a trailblazer. I just can’t decide if I should go with sub up or back. I think I’ll do both port and sub facing back.

[@DIYAudioGuy]

Test it out and see how it works. A lot of people think that a box sounds better with some kind of stuffing, if nothing else it will help with standing waves.

[@Thumper68]

@@DIYAudioGuy I usually use it because of to small of a box just working with what I had already. Ive never liked the sound when the box is stuffed full. I have had good success using blanket style poly and using adhesive spray on the walls and applying a 1/2”-3/4” layer. Of course this also keeps it in place in ported boxes eliminating the small chance of anything going into the coils.

[@DIYAudioGuy]

And you have a big SUV, so plenty of room for a big box with a big port.

[@frenchtoaststv]

what would be the best tuning frequency for small coffee shop/ restaurant?

[@ashleykellow5657]

Ive learned loads these are great videos!! 🙏 Does it matter if the port extends out of the box?? Im building the box for structural sound but im constricted a little with space so would be ideal to make the port longer for obvious reasons, im going to fibreglass over top wich will hide it all and look awesome in the boot of my car for the end design i have in my head.

[@DIYAudioGuy]

There is a lot of debate on that question -- how far can the port be away from the driver, which direction should you face the port relative to the driver? I am firmly in the "it does not matter much at all" camp. The wavelength at 100hz is over 12 ft. Which is longer than the cabin on everything but the largest SUV's and vans. So if you are in a typical car trunk I don't think it will matter as much as the placement of the sub and port in the car.

[@ashleykellow5657]

@@DIYAudioGuy ok thanks, the box(x2) will have to be 0.02 cubic inch with an 8inch inverted sub. I used the Precision Sound calculator that u mentioned but its a ridiculous amount of port length even for 40 hz so im assuming ill still get that kick from it? But just no real low frequency that im after. Just worried about damage on the drivers thats all.

[@BabyCharlotteschannel]

@@ashleykellow5657 Yeah although most all of the sub amps I have had in the last probably 15 years or so have had subsonic filters, I much rather have the box tuned low enough to either not use the filter or have it turned to like 25hz

[@UniqueChannel654654]

How do you calculate your port when you have two subs sharing the same airspace? I've got an odd shaped console where it would be easier for calculations to just share space.

[@DIYAudioGuy]

kzbin.info/www/bejne/eGHGooaqaLeBgZo

[@valentinavalero9177]

Very interesting but, in spanish. Thank you.

[@DIYAudioGuy]

KZbin has a multi-lingual caption feature. I think it needs a person to translate, several of my videos appear to have been translated in many different languages. It is cool to think that people all across the globe come together to watch videos about speakers.

[@democratssuckcritic1030]

man i have ben trying an just dont get it i have 2 skar VXF i would like the Xmax without going over for maxium sound as well as SPL an dont know what i should do . can u tell me wjhat i should do an i will do