DIY Bookshelf Speaker Build - Passive Radiator

This is a High-End DIY bookshelf speaker build using Morel active speakers and a massive SB Acoustics passive radiator on the back. All the parts and building instructions can be found on Audio Judgement website.
Bookshelf speaker build guide : audiojudgement...
DIY Audio Courses : audiojudgement...
Music Credits:
"Werq" Kevin MacLeod (incompetech.com)
Licensed under Creative Commons: By Attribution 4.0 License
creativecommons...

[@ianhill20101]

Builds keep progressing, that's what i like to see clearly a man with a passion

[@iliascharis5668]

By the way the frequency response on those u made was impressive......keep up the good work .....

[@eddies3728]

Nice Design.

[@DonnieMulligan]

Nice Job, Love the Zebrawood veneer!

[@eugendragut7741]

Bravo pt. ce faci, imi place sa vad ce mai scoti nou in domeniu si sa invat cate ceva. Succes in continuare.

[@atangens11]

Very informative video. Thank you! Also thanks for your courses on Udemy. Very helpful for understanding all aspects of sound and acoustic. Very recommended for those who want to learn speakers design process .

[@stephenyoud6125]

Impressive frequency responce, well done ! for the veneering,look at Peter Rawlings videos, building the kits from GR - Research. he uses paper backed veneer and a water based adhesive which is applied to the box and veneer, left to dry and ironed on with a clothes iron. Perfect.

[@colbydolby6559]

Marius, it's time for you to go on 12 volt talk so you can blow your channel up. ..zebra wood..my uncle made a pick guard for my Gibson sg out if zebra wood. It still looks fresh to this day.

[@rosselliot8971]

Your channel is fantastic. I'd like to see a video about cabinet resonances, and also the effect of isolation/coupling of the cabinet, for instance with floor spikes.

[@diy-speaker]

I've decided to use a hardwood for front buffles. It gives the best look and solves all problems with edges. It can be colored with all sorts of funky colors with wax-oil to achieve better contrast with the other parts of the box.

[@diy-speaker]

@@chanslorvalorum6905 couse it's hella expensive compare to mdf or plywood, hard to find, unstable and will crack and serve no noticeable purpose in the other part of the box.

[@dtibor5903]

You should have added just a bit more volume to the box to hit that 50hz sweetspot, great job!

[@mndlessdrwer]

wood can be softened for bending either with steam or with ammonia vapor. I'd recommend the former, as ammonia is rather hazardous for your lungs. It also tends to cause the wood to discolor.

[@gipdog4]

Hey very cool work here! Frequency response profile looks great. Listen, it would be really cool if you could make a budget version of this video. Just to set the path for the beginner/wannabe audiophiles! Keep up with the great work!

[@davidzoller9617]

To apply venire over rounded corners you may try this: Put painter-tape over top side of the venir and make the backside wet with a sponge in that area, so it gets a little more elasticity.

[@iliascharis5668]

Try to do open baffle speakers like pureaudioproject ones with an actual good frequency response and a good simple cross over and u will go viral .....trust me .......open baffle is the new trend ....

[@criper80]

open baffle needs a lot of space behind it , winch most of us do not have

[@iliascharis5668]

@@criper80 one or 2 meters into the room not that much as u think

[@carlose.martinez545]

Most chamfered front baffles I've seen in KZbin used real wood panels. I would love to see a version of this box using Chinese Aiyima speakers and passive radiator. Those are speakers we can find for a reasonable price if you do not live in the USA.

[@sahitwahyu]

Why doesn't the video have a sound check?

[@davidokon2988]

Nice

[@Luke-qs2cg]

That passive is almost like the ones in my moded mythos stl

[@Mahan150]

Please try to show making 1 box. 2nd box automatically understood. So save time and internet data consumption.

[@yuvrajsingh2696]

Cool 😎

[@shining31]

Nice work ! It could be interesting too, to show how did you designed the box (Vb Fb etc...) how did you tuned the PR etc ... :) Ohhh! last, shame on you :) :) 140 vertical db scale to show the FR .... :) :)

[@AudioJudgement]

I did absolutely nothing to the passive radiator. It does have a thread if you want to screw some added mass to it. However, It must be something custom as it doesn't come with premade weights. The scale is up to 140 dB because I have a high resolution monitor and it fits a lot of info. You need to look at the graph increments, which is 5dB steps. It's pretty standard if I'm not mistaken.

[@garlicbad]

Solution: A. No chamfer or B. Veneer all around except front baffle (paint it)

[@amaldevhareendran2389]

is there any problem when the passive radiator is smaller than woofer?

[@AudioJudgement]

Most likely, yes. But it depends. If the passive radiator can handle serious Xmax, then it can work.

[@halrichard1969]

as long as the passive can displace roughly twice the air volume of the Driver you will be close to optimal. A Passive with the same volume (same size) as the driver can work if it will travel twice as far (back and forth) as the driver travels. There are several calculators and answers for this on You Tube and the Web. Check it out.

[@lehoang9673]

Hi sir, ur videos so great. Can u explan for me how Bass Radiator work ? And what's different betwen Bass Radiator and Ported ?

[@alejandroleon3365]

Excellent video. Thanks a lot. I have a question: how does isolation affect the sound quality in the speaker? if i include a lot of insulation can i improve the sound quality? What is the desired isolation limit? What is the minimum limit?

[@AudioJudgement]

You don't want to add too much, unless it's a sealed box. Otherwise, lining the walls is just right.

[@alejandroleon3365]

@@AudioJudgement I appreciate the speed of your response but, unfortunately, it does not solve my problem. It's funny, I can't find a place where I can read what is the role of isolation. Everyone puts insulation but the amount, thickness, effect on sound, etc. are not defined. A totally sealed box gives the same result (I define totally sealed: I only leave enough space for the connections, the rest is, for example, polyurethane foam) as a sealed box that only has partially covered walls (I define partially covered: 1 cm of polyurethane foam)? Honestly, I have not done any tests but the sound qualities must be altered, that's intuitive but ...... for the better? For the worse? This is my question. Can you help me please?

[@AudioJudgement]

@@alejandroleon3365 The main reasons you use dampening material is to absorb standing waves, diminish panel resonances and to increase the perceived volume of the box. In a sealed box you can do that with no drawbacks and that's why you fill the box. However, in a bass reflex/passive radiator, you will diminish the effectiveness of the port/PR as you fill the box more and more. So, you have to balance things out. That why, usually lining just some of the internal panels is the sweet spot.

[@alejandroleon3365]

@@AudioJudgement Totally agree and grateful for the quick response, almost WhatsApp, ha, ha. Let's forget the difference between sealed and others. If I fill the box completely except for the connections, I should not obtain almost an anechoic or anechoid chamber, that is, it would be a box designed to fully absorb the reflections produced by any acoustic or electromagnetic wave on any of its surfaces and the sound would be almost perfect, is this correct? Do you want to make a speaker box that is as close as possible to an anechoic box?

[@Clobercow1]

The build looks like a lot of punch in a little package. Nice work! Would you be interested in showing distortion / waterfall data for your builds? How much power headroom does this speaker have?

[@chaseleim4773]

probably like an 80 watt system each speaker but would probably take upwards of 200-400 watts if the power is clean (unclipped and undistorted)

[@marubeni4159]

Au iesit super. Daca e pasiva e mai mica decat activa, este vreo problema.....hmmm

[@jerichotm2122]

Ow! Passive radiator... why didn't you say so? :) One doesn't need any subwoofer in this case... for a small room, I presume...

[@diy-speaker]

I've tried to record my speakers from 30-40cm distance by one channel at ones. Then combine them into stereo file. For a comparison purposes it worked quite well. But i still can't find a way to add mic file correction for a better result. The mic from sonarworks.

[@JasonLeaman]

Good video, are those cabinets a bit small tho ? Are you going to fix the crossover for the tweeter ? its a bit hot, and IMO it should start to fall off at 10kish.

[@stephenyoud6125]

Great Build Marius. But why dont you clean the edges with a flush trim router in your palm router. and try the veneer glue that you let fully dry and then iron on with a clothes iron..?

[@AudioJudgement]

I think the iron is used when the veneer has the adhesive pre-applied. This is just regular veneer, and I'm using contact adhesive.

[@stephenyoud6125]

@@AudioJudgement no it’s a glue you apply yourself in both surfaces, let it dry and then iron on. Peter Rawlings did it on one of the GR-Research builds.?. I also just watched s gut do it using regulär white wood glue

[@thomasschafer7268]

Eine der beiden Spulen sollte besser hochkant stehen. In 90° zur anderen. Bei so kurzem Abstand.🇩🇪👌👌

[@Michael-mai]

Thank you for your selfless sharing! May I ask if there is any negative effect if the beveled edge of the front panel is changed to a rounded edge?

[@AudioJudgement]

Nope. Probably even better if you round the edge.

[@jf4828]

The smoothing around 600-700Hz looks like you merged near field and far field data there? I'd be curious to know what the window size was as well as measurement setup (distances between surfaces and mic to speaker) for the far field measurement. I'm guessing the smooth bump in the 800-900Hz region is lack of baffle step compensation looking at width of speaker. I've stopped using the merged measurement quasi anechoic measurement technique because aligning the SPL and phase correctly is very hard to do properly. My guess here is that the nearfield SPL is slightly higher than it should be and the bump is the result of a lack of baffle step compensation that would be more obvious if near field SPL were not elevated. I'm suggesting this because this is what I did myself several times before figuring out why I got good measurements but a sound I didn't love... Instead, I now take far field measurements good down to 300-400 Hz by getting good reflection free measurements by getting away from boundaries and assume the bass is OK; this works fine for a 2 way. This decision came after immediately getting better results after switching to far-field only measurements. To ensure proper phase measurements (very important), do NOT move the mic between woofer and tweeter measurements. If you want low frequency accurate measurements better off using ground plane technique outdoors.... There is a reason you don't see low frequency resolved measurements on sites like Troels Gravesen. Without a Klippel scanner or anechoic chamber I think you are better off ignoring anything below your required window frequency...... Overall nice build and love that you are spreading DIY speaker building with your well put together videos. I look forward to watching your future builds!

[@AudioJudgement]

Hello! The response is indeed a merge between far-field and nearfield. The far-field response is accurate down to 275 Hz (I have a large room) and then the merge is done at about 350 Hz. The quasi anechoic measurements are pretty accurate. You are probably not applying the low frequency box diffraction function to the nearfield response. Nearfield measurements simulate an infinite baffle scenario, and in reality you have a finite baffle box. After you apply the function, the bass response goes down (because in reality not all the frequencies get boosted by +6 dB like in an infinite baffle scenario). I'm guessing that's why your bass response was misleading. I too only use far field measurements when designing crossovers. The low frequency information is not very useful (as the crossover point is not in that region) and indeed the phase information is much more accurate if you don't merge with some other response.

[@rezo786]

Very nice What was the thickness of the veneer? What was the price like for it it? Here in South Africa I paid R340 for 2 Square meters

[@AudioJudgement]

Depends on the type of veneer. This was like 0.8 mm thick and the price was 12 euro per m2

[@tomasz5904]

great channel, great courses :) I have a question because I don't know it yet how to take measurements to get full frequency response 1. measurement right 2. measurement left 3. measurement nearfield right 4. measurement nearfield left 5. measurement ps/bs nearfield and should I add all these measurements ??? have I missed something?

[@AudioJudgement]

First of all, you measure either right or left. I did both just to check if they are the same. You first measure far field, and apply a time window to the impulse response according to the size of your room and when you register the first reflection. Then you measure the bass speaker nearfield, then you measure the passive radiator nearfield, then you adjust the level of passive radiator according to the size difference compared to the active speaker. After that, you combine the 2 nearfield responses (speaker and passive radiator). Then you apply a function to correct the resulting nearfield response (which is basically a half space measurement) to what the response would truly look like according to the baffle size. Then you adjust the nearfield to far field level. Then you splice the 2 curves (nearfield and far field) somewhere between 300 and 700 hz where both measurements are accurate. And then you get full frequency anechoic response.

[@tomasz5904]

Thank you - it's more complicated than I thought. Could you show it on yt or do you have a course that shows how to do it?

[@AudioJudgement]

You can check my acoustics 201 course

[@biscoitoseno]

Are you BR? 🇧🇷

[@Andrewatnanz]

similar to Buchardt S400

[@WillyLax24]

Is that a metric circle cutting jig on your router? If so, can you provide a link to where you got it? I am in the United States and have been unable to find a metric circle cutting jig.

[@AudioJudgement]

No it’s not. It’s a pain for me too to make conversions every time. Hope jasper will make a metric jig some day.

[@ubacow7109]

Why don't more folks use multi layer glued HDF Instead of MDF?

[@gdart9521]

Hey bro where did you bought the passive radiator

[@AudioJudgement]

soundimports.eu

[@Made2hack]

Nice job on the veneer. I've not been able to manage anything remotely close to your quality on my speaker build.

[@JukeboxAlley]

What kind of router tool is that you used?

[@AudioJudgement]

it's called jasper circle jig. You attach it to your router.

[@anandshah71]

Anyone tried peerless drivers I don’t get morel in my country peerless tang band and SB I get

[@AudioJudgement]

I have worked with Peerless drivers and are good quality for the money. They have my recommendation. However, if you are planing in using this box design and swapping the drivers for some peerless ones, it won't work. You can use Peerless drivers for other projects though.

[@user-mk2tl8rs1m]

Nice radiators, where did u get them ?

[@AudioJudgement]

They are made by SB Acoustics

[@infectedscience6674]

Dude I need one such radiator 😍😍 please tell some way to have em here in India 🇮🇳 please the shipping cost of aliexpress is way too much I need some safe and secure alternative at a decent price please help me brooo

[@AudioJudgement]

audiofy.in/ is an official distributor for SB Acoustics in India. Ask them if they can order that passive radiator. In the description you will find the exact model name.

[@infectedscience6674]

@@AudioJudgement thank you so much❤😊

[@infectedscience6674]

@@AudioJudgement the number is switched off I sent them messages on whatsApp they were last seen on 18th June and on their bio they've mentioned all online orders will be cleared after lockdown 🥲🥲 anyways thanks for your help I just wasn't lucky enough 🙃🙃

[@user-so3ig4xm3f]

Как засунуть качественные и дорогие динамики в хреновый корпус и гордиться этим до старости.

[@ludovicobonfiglio7563]

Hi, how can I contact you?

[@manmeetjammu]

Your room is much darker

[@manmeetjammu]

Just a demo .

[@jaybonline]

no sample audio? thumbs down

[@AC-zk2eg]

Nice