Thank you for the obvious time, effort and expense (for the test equipment and software package)and sharing it all; interesting presentation. I started installing car audio in Canada in the early 1980s, became an Alpine certified installer in 84 and actually ran the Pioneer Electronics Installation School for the 6 years I worked for them in the 1990s. Have created many "IB" installations starting in 1982. In my experience, the primary reason for IB/Free Air has typically been for space considerations, which leaves the trunk a lot more usable than when using an enclosure. Two elemental physics criteria are not mentioned or discussed, I would like to add them here: 1)When the rear volume exceeds the vehicle interior volume, the "enclosure" design parameters are reversed. The vehicle interior becomes the enclosure, especially with an opening behind the speaker into the atmosphere. Low frequency speakers are influenced equally by the acting air pressure/resistance both in front and behind them and when the interior begins to compress more than the trunk the parameters switch. 2) The "Quarter Wave" edict, where the vehicle interior maximum dimension is a massive influencer on low frequency propagation. (in many vehicles, facing the drivers in an enclosure towards the rear often/usually works better for that reason. Some of the later explanations of speaker overlap/underlap and the crossover suggestions does not mention the effects of using 6 and 12 db/Octave crossovers to induce some phase shift to get the speakers to work better together. My two cents worth of thoughts, once again, thank you for taking the time to create this video, great to see IB is still a thing, especially in other markets.

You covered box colouration in conventional enclosures, but one thing to add to that is: cones are not soundproof - sounds originating inside the enclosure can and will be heard in the front of the driver as they propagate through the cone. If you want to test this, just place a bluetooth speaker inside your woofer box and check out just how much sound you can hear coming through the cone.. IB setups generally result in far less back wave distortion/sound making it through the cone. It also becomes a small con in "true IB" setups, because road noise can and will make it's way into the cabin in the same way.

Best explanation of IB ever. Great job

At 12:50, the station wagon with the 24" sub actually does use a cover with foam to protect the speaker. They sometimes remove the cover at shows so people can see it better.

Thank you Very much appreciated Great content, video, audio, commentary, tutorial, demo, lessons, schematics & humbleness You are truly a gifted teacher Look forward to more content Your contributions simply amazing 🙏

Great video. Lots of detail involved that many will not take the time to explain. Thank you.

In the US, it can be a bit more difficult (at least in my limited experience) to find the PA speaker grille material. When I went to IASCA Worlds this past year, I spoke with a couple of people with IB setups. They suggested using snowmobile pre-filter material. It is more easily available in the US and works the same as the PA speaker grille material.

Nice video Nerijus 👍 My amarok ib sub’s can play nicely ~10~80hz, couse probably the shape and short cabin and dual ib 6.5” in kicks from 40hz sollid. Very easy integrate and work with it and i don’t need a front sub. I have few diff presets for competition or “daily sq” with differential rear fill where kicks up front plays down to 40 and subs just covers lowest octaves (still can handdle louder than moderate level). If i want to go even louder - i crossed at ~80hz (still with good enough sub integration up front). The car shape, install, location, drivers selection dictates big time for SQ

Wow thank you so much for the information. Clearly, your put a lot of work and time in this video. I found you channel when I was making pillars, you've been a big help to my recent transitioning to Sq.

Beautiful explanation of driver selection for IB.

Nice video!Thanks for clearing things up!!! Just want to add on that at 11.00 its my car and I have been speaking to 1of the best installer in the UK and they told me that for 15"woofer I need a 12" hole.

BMW all play into the sill, they are Ib not sealed 👍🏼 Normally the underside has a plastic cover so you space it down a little if you cut through the floor and block off the sill so all pressure stays away from the sill as the plastics flap pretty well from the factory 👍🏼

Great job explaining the subject. Thank you.

Amazing video. You gave me so much to think about and plan for. Damn good content.

I tend to often object to using home audio rules to car audio because of major room gain differences thus I don't necessarily agree with this "true IB" that gets used often. No strikes against anyone suggesting to cut open a car, but the goal of any IB is to design is to choose a driver where the rear space is higher than Vas ad to not raise Qtc over Qts, yes. That said, this is easily acheived IF you don't use gigantic or super high Vas subs. Many stock stereos achieve such with a single sub albeit output may not be what an aftemarket stereo is caoable of. So, it is very possible though not often practiced to design an aftemarket uograde that achieves a "trunk baffle" setup without raising Q over the applied sub.. Still, overall Q (final response) affects both true and trunk which makes either somewhat of a misnomer. Too often, the application excludes careful selection of drivers to achieve suchz instead just opt for ones with so much beef to where cutting open a car is required to fall under such. Not practical. As a side note... test subs to confirm parameters. The Ultimax and many others may not measure out what most think. That would be a good plot twist

when talking about xmax and bottoming out, going past xmax (linear excursion) wont make it bottom out, but reaching xmech (mechanical excursion) will make it bottom out.

Qts of .07 or higher is desireable for IB applications. If driver's manufacturer doesn't show Thiel/Small perameters, stay away.

Hi there. Thanks for the info here. Bit stuck for space to install something as i need the boot. There's a full size spare wheel which i'm considering putting a shallow mount driver into (i need to keep the wheel unfortunately). I measured the volume and may have found a suitable Focal 10" but, after material thickness, clearance for excursion etc etc, i may be lower than the recommended minmum volume so i'm considering trying it open baffle first before sealing. Going to mould fibreglass into the wheel itself. Structurally it will be plywood which i'll try out prior to setting into the fibreglass. The QTS is 0.643 but no excursion info. I already have low expectations with so much compromise involved!

So long story short, IB will play loud and clean with lower power and is king for SQ but in a sealer you can dump a lot of power and pound harder at high volumes without hitting Xmax on your drivers and is a SQL set up, more for what 99.8% of people want when installing a system, you need to be hardcore into the SQ competition scene or just have no room for a box to consider it.

You’re awesome! Thank you!

Good day to you. I am from Jamaica, I love your explanations quite clear. What I need to know is the photo in your thumbnail the one with a speaker mounted in front of the gear lever! 😮 Is that a real picture and if so whose car is it and their story of how they did it.

Do you know of any 12" midbass drivers that would have rather good sensitivity but also be good for IB? Currently I have lavoce waf123.03 mids in my doors. Seem to be a good blend of 500Wrms power handling, 97dB sensitivity and almost 10mm of xmax. But the Qts is very low.

very nice video, I made an attempt to do a trunk baffle but was informed my subs did not qualify and would sound better in a box with aeroport. I'm still interested in getting a IB sub but it looks as though Fi discontinued their IB line. nothing comes close to the Fi IB as far as Qts. any suggestions?

I'm sure you didn't intend this but I fear people will steer away from IB if they think they'll also need a front sub. I've done a lot of cutting on my car already but I draw the line at front sub lol. Anyway, great video as always

Very simple correct cabinet more bass. Cars have cabinet gain or loss and a resonant structure . Strike the steering wheel to find it then build your box s accordingly usually turn it away from the front of car. Phase is important. Amateur keep studying and ask some pros also

I don't think I've seen anyone mention it, wouldn't true IB be audible outside of the vehicle? Idk if other cars in traffic or pedestrians wanna hear my mid bass and subs lol then again maybe I just worry too much 🤷‍♂

IB24 FOR THE WIN

Why not split the difference? Turn the gain down on the IB sub about 5-8 db, and then use the DSP to cut the IB sub and keep the 45-80 hz region?

This video is such a wealth of knowledge. Thank you. I will share this to friends to explain what I'm doing to my car. Thank you for testing the hole opening effect on sound. I have a 10" hole for my 18" currently in my spare tire well. Seems to work great but was thinking to open it up to 12" I feel better about it now at 10 but if I get a sub that has more excursion I may open it up to 12. What are your thoughts on fabric and foam protections as far as efficiency loss and backpressure ect?

Will a sealed trunk enclosure with a hole in the rear deck give a similar result? Or will that be considered a 4th order?

Could you just mount in a shallow box with a port

Will the sundown e v4 15 make a good IB Sub ? As far as I can tell it’ll be decent comparing the ts parameters with the fi

Yo, when you loaded up the response of that FI 315 in IB I had a *_FIT_* because as a guy that likes 150+db of bass, that's EXACTLY the kind of response that I want... What's the mounting depth on that, and how much space would the cone need in a down-firing, "slot-loaded" blow-through style setup in a single cab 2009 Ford Ranger (compact pickup truck)? I have about 16.5 inches (42cm) of total depth in my cargo box to work with, and I can fit three 15s across the span of said cargo box, which is what I plan to do since I want to maximize bass SPL while still having crazy good SQ. I'm not sure I'll be able to do IB midbass due to how claustrophobic my kicks are AND the fact that I have a clutch pedal AND a floor-mounted parking brake, but I might still try to do it, regardless.

Im here for the free cookies !🍪🍪🍪

15:30❤ 🔊

Can you please explain why you don't want to cut the peak to flatten and extend the curve. Thanks

Dont you have less cone displacement on the back side then you do from the front side?

So basically like your STOCK SPEAKER SETUP. SMH

For those over protective parents

shame to see that M2 Competition being butchered like that.