​@Tarrin Pearson - Leary its a 8 inch dayton ultimax.

Thanks for clearing that out. It’s in even harder to get it right as a non-native English speaker. :)

@@AudioJudgement Your English is always going to be better than my Romanian. (Sometimes my English is not so good, either...)

Please refer to Cambridge English Corpus and see that dampening is not only about making things wet. Also damping is a noun, not a verb. Also read definition of words "damp", "dampen", there are at least two meanings: 1) to make wet, 2) to reduce. Dampening is not a separate word. Example: This is caused by the dampening effect of collisions. (From the Cambridge English Corpus)

@@fort9983in an engineering context discussing vibratory motion, “damping” is the correct word.

How is it in phase if quarter wave is 90deg and back side of the speaker is 180deg? We need 0 or 360 to be in phase.

Actually it is Tools -> Design Wizard -> TL Design. But thanks for the tip.

I have also tried using this formula of displased air volume:-. f=C/2π√A/l/v where:- A---sectional area of duct. I----length of duct. V--the active displasable volume. C--speed of sound in air and it works well with small drivers of around 12cm diameter and less but when it comes to about 15cm and above the sound only gets muffled up. Why could this be happening?

The area of the line needs to be at least 2x the effective area of the cone. So, you can imagine that the box size would be huge. It's the same thing as with 1 speaker only that the area of the line needs to twice as large.

Have a look on hexibases channel, he build a Tiny dual sub t-line. Maybe thats helpful

How do you simulate it in hornresp

Are you describing a 4th order bandpass?

I thinks so, yes. If I were to characterize it, I would say it sounds very transparent. It's like you don't even have a subwoofer. But if you take it away, you notice that something is missing.

Ideally you would wan’t to burn-in the driver, measure it, and use those numbers. But manufacturer specs are ok too.

@@AudioJudgement thanks! Sure after burn in.

@@AudioJudgement Depends on the manufacturer. Dayton is usually pretty good with their published specs (I've used many of their drivers). Some other manufacturers, not so much. However, they're not difficult to measure, using a simple DIY Impedance jig and the freeware REW software. Or you can just do like I did and purchase a DATS for that purpose.

Here you go: www.soundimports.eu/en/monacor-mdm-30.html

Not sure if you still need the answer but basically yes. You can also simulate double speaker in hornresp. Also you can experiment and make the area of your pipe smaller than total Sd of your drivers. Sometimes it works nicely

What really brings about these peaks?

Eggcrate foam absorbs high frequencies. They have some purpose.

Actually, rolling the windows down does transform the car into a chamber. The whole thing is basically a 4th order bandpass. The subwoofer is already in a sealed box. And the car is the ported chamber. The port being the window. Of course, lowering all 4 windows all the way down will negate the effect. In my experience rolling one window not all the way down, increases the perceived pressure. Anyway, regarding your question, a sealed subwoofer usually doesn't play linearly down to 20 Hz. But if you DSP the crap out of it, it can do it.

@@AudioJudgement going for a t-line since all doors will be open I’m going for a pro audio built but what does a isobaric do

I would go 6th order bandpass

I can see that appeal in building a T-line floorstander for a full range speaker like the Fostex builds. But if you want to build a subwoofer, bass reflex wins in so many categories, it makes the decision quite simple.

​@@AudioJudgement Thank you for answer, Marius. Regarding complexity to produce is obvious winer is bass reflex. But in your video you wrote TL sound very different compared to any other enclosure type. This is most interseting part for me. What do you mean? Is it sound better or worse? What is you impresions? If it possible to describe with words.

@@evaldas7346 I like how it compliments a pair of fullrange speakers without being too obvious that there is a subwoofer present.

With today's high performance subwoofer drivers, box design programs usually end up suggesting small boxes with long large vents. In those cases, it might be best to just build a TL instead to ensure that you don't end up with big peaks and notches in the passband due to pipe resonance effects. And with a TL you get the added advantage of the internal panels also helping to brace the box for better bass performance. My "Boom Unit" build is an example of a design that looks like a shelf-loaded vented box, but was actually designed using TL techniques to reduce the impact of pipe resonances. More info here: www.diysubwoofers.org/projects/home/boomunit/

@@AudioJudgement Thanks

I'm sure you can, but I don't really see the reason why not use some of the more friendly apps out there.

@@AudioJudgement ok thank you

It can be done, with the added advantage that Hornresp can show you how the positioning of both the driver and the vent in the box can impact its response. I use Hornresp for all of my box design work now. However, instead of designing first in Hornresp and then trying to translate that to a build, I use one of my BOXPLAN workbooks to start with an idea of what I want to build, and then tweak the Hornresp sim that the workbook produces to get the best results. BOXPLAN-VBSLOT and BOXPLAN-ODOV are the ones I'd use to design vented boxes with Hornresp. The BOXPLAN workbooks are available here, all in various stages of completeness :-) : www.diysubwoofers.org/sheets/

hornresp.net/

There should be an executable file hornresp.exe

It's the only way to make an anechoic measurement without an anechoic chamber. At 1m you capture room response as well. Nearfield measurements are accurate only at low frequencies (depending on speaker size) and therefore work great for subwoofers.

Hello! Everything you said is correct. However, transition from full space to half space to quarter space results in +6 / +12 dB gain (not 3dB increments).

@@AudioJudgementwell , here is some theory "Space-loading loudspeakers means that the otherwise spherical radiation is limited by a boundary or boundaries. Some common scenarios are shown in Figure 1, and are often described by the fraction of a sphere to which the radiation is confined. Since these are fractions the correct usage would be "1/n-space" but I have used the common descriptors that omit the "1/". The classical theory states that the effective gain realized from incoherent summing due to radiation confinement is +3dB for each additional boundary, and that +9dB relative to the free-field response can be achieved by "corner-loading" a loudspeaker. In acoustics the results are never that ideal, so part of my motivation was to determine when this or something different happens. We would certainly expect the boundary interaction be frequency-dependent, and indeed it is" see page 4 www.prosoundtraining.com/site/wp-content/uploads/2012/03/VOL36_DEC08_Boundaries-1.pdf

​@@rolosaenz The author of the paper you linked want's to dispel the fact that when placing a speaker near a boundary, the gain is not +6 dB, it's more like + 3 dB. There is no denying that measuring a speaker inside a large room will result in all kinds of results depending on the box size, number of speakers inside the box, mic positioning, room modes etc. You can even see that when measuring a horn, the gain is basically +0-1 dB regardless how many boundaries. Nevertheless, the theory is that in ideal conditions the increments are +6 dB. Check the graph at the top of page 6, where you can see the 6 dB difference between graph lines. Anyway, I if you design, more or less, conventional style boxes for subwoofers in Hornresp and play with the solid radiation angle slider, you will get 6 dB variations between ticks. However, if you use the speaker-box example which comes by default when starting the app (which is a horn), and start playing with that slider, the result are quite different. This answers my question of why that slider is even there, and also reminds me of how limited is my experience with horns.

Well, your mom is so fat she is in fact on every app!

Yeah, this happens sometimes with "indie" software, but I'm sure it's a false positive.

@@AudioJudgement It is. Windows 10 blocks "unsigned" apps, and the Hornresp program is unsigned. The warning can be ignored.

Mike jones!

Hello! You are a bit confused. Transmission line is totally different compared to a ported enclosure. While they look similar the working principle is not the same. Bass reflex is a resonator while TL is just a wave guide for the back wave. As the back wave travels the long line, the phase is shifted and when it comes out, it adds with the front wave. A TL is not even a box, per se. You can slap a long pipe to the back of the speaker and it will work the same way. A transmission line is more related to horns than to ported enclosures.

@@AudioJudgement Hi there! Sorry for late reply, just found your comment today. So I think you are a little confused as well. I know well how to design a transmission line and one thing I know for example is that there are variations of it. You have a back loaded horn also known as a flared TL, a tapered TL, but I want to focus on another variant that is mass loaded TL. MLTL is basically a bass reflex enclosure that was designed with a transmission line model. There are very concrete reasons to pick one form over the other and they are dictated by driver parameters. To make the story short: it all comes down to how much volume in the enclosure you can have before the excursion is too much. So if you think about it this way, you'll soon be able to say, that a straight TL can be also imagined as just bass reflex enclosure where the box volume is zero and the port takes the entire loading. The volume of the duct matters just as much a the volume of a ported box! This is very important, because you need to be able to determine which driver will work better in a small reflex enclosure, and which can handle a TL, and if so then which type of TL is best. For example none of the popular SB acoustics drivers are suitable for a straight TL, but some are OK in a small MLTL. You can say that a TL is not even a box, but then is a bass reflex a box? :) It is a box to frequencies above system resonance and not a box to frequencies below it. In case of TL the dropoff can be made less steep, but it doesn't escape the laws of physics. How did you say it? " As the back wave moves the air in the port, the phase is shifted and when it comes out, it adds with the front wave" ;) You see what I did there? In practice the major sonic difference between a BR and a TL is that TL has a lower Q resonance, which means a less steep slope. It also implies less stuffing, because we are lacking a bit in the amplitude. The unspoken difference between these two concepts is that if you simplify in your mind that TL is roughly the same as BR, then TL model still gives you more insight into what happens in the enclosure. You can model a driver with TL model and with BR model and end up with the same exact enclosure. It's very unlikely, but only because when you see the duct resonances (port resonances in case of BR or MLTL) you start playing with placement and stuffing to make it more refined, then what you'd do given just the lumped model of a resonator. Not sure if Hornresp can do it as well as Leonard Audio software that I've been using in the past. Either way you see the wiggles and you want the lowest ones to cancel out, so you nudge the port every mm into place. :) That's about it. That's the only significant difference on designer's side unless you have a special driver with suspension stiff enough to be mounted into a straight duct or a horn. As I said it half year ago, designing the duct is chasing a moving target. When you change the length of the TL to match driver resonance, you change the volume, which changes the system resonance, which changes the duct length, which changes the volume... Unfortunately it's not a playground without limits that people make it out to be. People who design bass reflex enclosures often put bricks inside, when the midrange distorts from overexcursion. With a TLine it's not as simple, so it's a good idea to find the volume first. From there you make your decision on which variant suits the driver best. If the volume is nonsensical, then you make a FTL. If it's large, then straight, then tapered... Finally the glorified BR also known as MLTL. You can look at Qts and the variants of Xmax, but I noticed that often people online will tell you when they make the volume smaller. That's how I designed MLTL with SB17 and SB23 drivers even without the large signal Klippel data.