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Lockdown Audio - A 12v 3way Small Rig Build

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Category: Plans
Forum Name: New Projects Forum
Forum Description: Forum for new speakerplans projects, in memory of Tony Wilkes, 1953 - 2014
URL: https://forum.speakerplans.com/forum_posts.asp?TID=105202
Printed Date: 10 August 2022 at 5:40am
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Topic: Lockdown Audio - A 12v 3way Small Rig Build
Posted By: Jack1991
Subject: Lockdown Audio - A 12v 3way Small Rig Build
Date Posted: 07 May 2020 at 9:21pm
I have always wanted to build something along the lines of this sort of thing for ages, but i knew absolutely nothing about it until recently when i joined a 12v audio facebook page in December and started to learn all about it. Then got pointed to this website too which has been even more helpful and full of great stuff!

Then when all this coronavirus stuff come around i thought perfect time to start a project being on lockdown etc.

After alot of reading around heres what i decided to go with

Subs: 2x Tham 12's, The Box Speaker 12-280-W drivers

Mids: 2x 10" Beyma SM110/N in custom enclosure

Tops: 2x 1" P-Audio BM-D26 Mk2 30W Compression Driver with B&C ME10 90 x 60 horns in custom enclosure

Crossovers: Convair Electronics 2-way Crossover 2.5KHz Butterworth

Started to build the first Tham. I went with The Box Speaker 12-280-W as they have been rated highly for budget 12v builds. Also the Tham style sub looked like a fairly straight forward design so a good one to start with as a newbie.




The sub driver next to my minirig


Put the minirig facing inside the Tham ๐Ÿ˜† really pumped it out! Cant wait to hear the actual sub in there now!๐Ÿ˜ƒ


Driver test fit


Then after building the first one i started on the second, and now they are both fully finished. Just need painting which i will do all together when the mids and tops are completely done too.


I added small strips round the inside edge to fit grilles onto.




Replies:
Posted By: Jack1991
Date Posted: 07 May 2020 at 9:27pm
UPDATE:

Then bought a Pioneer 8704 Class D 4 channel amplifier. Again these are highly rated on the 12v page.


The plan with the amp is to have the 2x subs wired in parallel and bridged to 2 channels. So they will receive 150w each. Then the mids and top will have a passive crossover per mid top so 1 mid and 1 top wired to 1 channel and then the remaining mid and top to the final remaining channel. They will be 8ฮฉ so will receive ~70w each.

Started to plan mids and tops now! For the mids theres a lot more involved than i expected. Working out exactly the right volume of enclosure using the TS parameters of the drivers and getting my head around WinISD was a headache! But once that was sorted, working out how to then best make the enclosure to that size wasnt as bad.

Google sketchup is really good to use for this i think. I havent ever used anything like that before so it was a bit tricky to get used to but gave me a rough idea what it would look like, much better than my drawings on paper anyway. Also its cool they have the measurements and sizes on there so you can literally make it to size.

Heres my first go at what i want it to look like


The mids with a view inside and ports


Once settled on design i began to mark out and build














Dry test fit


I wasnt overly satified with the look of it though. I think the mids look too wide. The ratio doesnt look right. Also a few other guys on here helped me out by explaining how i should angle the mids and tops facing outwards to reduce comb filtering and beaming. 

So back to the drawing board. After messing around some more they now look like this.


Much happier with the look of it now, also much happier that i have hopefully reduced comb filtering and beaming. 2 things i had no idea of and never heard of before. So lucky they helped me out before i glued it all together. ๐Ÿ˜€๐Ÿ‘๐Ÿผ


That sorted i glued the mids and tops


This is as far as i have got for now. Next up is sand, router edges, fill holes, then more sanding.



Posted By: dnbpc
Date Posted: 08 May 2020 at 11:21am
Looks wicked so far Clap

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Pick & Mix Soundsystem


Posted By: Jack1991
Date Posted: 08 May 2020 at 5:28pm
Originally posted by dnbpc dnbpc wrote:

Looks wicked so far Clap

Cheers mate!


Update: This afternoon i have sanded, then routered the edges, i used a 6mm round bit, filled the screw holes, then sanded again, first with 80 grit, then 120 grit, then finally a sanding pad which i think is ~240 grit.




Posted By: Jo bg
Date Posted: 08 May 2020 at 5:45pm
Wish my lockdown frankenbox looked like theese, good job


Posted By: Jack1991
Date Posted: 08 May 2020 at 5:50pm
Originally posted by Jo bg Jo bg wrote:

Wish my lockdown frankenbox looked like theese, good job

Thanks mate im happy with it so far! ๐Ÿ˜€๐Ÿ‘๐Ÿผ

I havent seen your frankenbox Jo, do you have a link to a thread or photo? Id be interested in seeing it! 


Posted By: imageoven
Date Posted: 08 May 2020 at 9:32pm
Good work.

I bet you'll be very happy when you get to hear it.


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Keep pushing on, things are gonna get better.


Posted By: Jo bg
Date Posted: 09 May 2020 at 12:40pm
look fo 12v scrap subwoofer build, recent thread in 12v forum.
title says it allโ€ฆ
actually i bodged up a better crossover from parts recovered from thrashed speakers and it behaves better now.
If next week work is still low i have plans either to turn it into a bandpass , or to build a couple 100 liters Th. let's see how bored I am and ehat plans the Miss has...


Posted By: Jack1991
Date Posted: 09 May 2020 at 1:24pm
Just checked it out the looks decent! You done a good job seeing as its its recycled stuff too. Look forward to seeing what you end up building next.




Posted By: Jack1991
Date Posted: 09 May 2020 at 1:31pm
UPDATE:

Done a coat of the Wood Dye on it all this morning. Only needs 1 coat of this. Then ill wait 24hrs and give it a coat of Danish oil, followed by another 24hr wait, then the final coat of danish oil.


I went with Light Oak colour


Then just standard Rustins Danish Oil to protect it and give a ever so slight sheen. Also brings the grain out nicely. I done them both on a tester piece of birch ply and it looks quite nice.



Posted By: Earplug
Date Posted: 09 May 2020 at 1:43pm
Looking good. I do like the natural wood finish. Makes a change from black!   Smile




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Earplugs Are For Wimps!


Posted By: Jack1991
Date Posted: 09 May 2020 at 1:54pm
Thanks man! ๐Ÿ˜€๐Ÿ‘๐Ÿผ

Yeh i do like the more natural look. Plus im kind of going for that old school reggae stack sort of style.

It does look quite orange at the moment but so did the tester piece. The danish oil darkened it a bit and made it look more 'woody' though.


Posted By: DJ-Dulux
Date Posted: 09 May 2020 at 2:39pm
Looks great...

Dupe...


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Dupe...


Posted By: Jack1991
Date Posted: 12 May 2020 at 8:17pm
Update:

Started getting speakon panels wired & ready, i used thin frame draught foam to put around the outside. As read elsewhere others do it do help stop air leaks.



Third coat done last night. So got them out in the sun this afternoon to dry and harden a bit quicker. Also fitted the speakon points and sealed around with sealant where the cable goes though any interior walls.



Then after started to fit the egg foam inside the mids



Also wired the crossovers and fitted them to the inside of the tops back panel.



Posted By: Natedub
Date Posted: 13 May 2020 at 1:15pm
Looks great Thumbs Up It might be worth considering upgrading to a second seperate mono block amplifier for the bass to get the most out of the Thams. The gm d9701 is a great class d mono block that actually achieves its rated specs of 500w rms at 4 ohms or 800 at 2 ohm. 


Posted By: Jack1991
Date Posted: 13 May 2020 at 1:33pm
Originally posted by Natedub Natedub wrote:

Looks great Thumbs Up It might be worth considering upgrading to a second seperate mono block amplifier for the bass to get the most out of the Thams. The gm d9701 is a great class d mono block that actually achieves its rated specs of 500w rms at 4 ohms or 800 at 2 ohm. 


Cheers mate! ๐Ÿ™‚๐Ÿ‘๐Ÿผ

I was actually thinking in future i might possibly make 2x Cubo Kick 12's and then look into getting a second amplifier. But thats far in the future yet as id need a DSP for that too and i dont fully understand them yet. 


Posted By: SamV
Date Posted: 13 May 2020 at 4:48pm
Tidy system :)


Posted By: Jack1991
Date Posted: 17 May 2020 at 10:12am
Update:

99% Complete! Just waiting for the grilles for the subs to be made and delivered! Well happy with it though. Need to do some messing around with the settings and EQ to get it sounding right but it was better than i expected! ๐Ÿ˜€


Also decided on a name: 
Lockdown Audio



Posted By: Bams
Date Posted: 17 May 2020 at 1:16pm
that is a work of art. can already visualise some garden parties around it.



Posted By: Jack1991
Date Posted: 17 May 2020 at 1:28pm
Cheers mate! Im real pleased with it! Only tested it in my garage so far think its definitely going to be far too loud for the garden! ๐Ÿ˜†


Posted By: infrasound
Date Posted: 18 May 2020 at 9:05am
Nice build. What music do you play?

You could consider mouth extensions next on your THAM12s if you want more output. See graphs below. +4dB @ 40Hz for an easy amount of wood.

This could be a good start point:
Start mouth area: 908cm2 (as per THAM12)
Finish mouth area 1500cm2
Length: 50cm

https://ibb.co/MGYdZZC" rel="nofollow">

https://ibb.co/mhy22r6" rel="nofollow">

https://ibb.co/YfC8mj6" rel="nofollow">

https://ibb.co/G3WtJVT" rel="nofollow">


Posted By: Jack1991
Date Posted: 18 May 2020 at 9:16am


Originally posted by infrasound infrasound wrote:

Nice build. What music do you play?

You could consider mouth extensions next on your THAM12s if you want more output. See graphs below. +4dB @ 40Hz for an easy amount of wood.

This could be a good start point:
Start mouth area: 908cm2 (as per THAM12)
Finish mouth area 1500cm2
Length: 50cm

https://ibb.co/MGYdZZC" rel="nofollow">

https://ibb.co/mhy22r6" rel="nofollow">

https://ibb.co/YfC8mj6" rel="nofollow">

https://ibb.co/G3WtJVT" rel="nofollow">


Cheers man ๐Ÿ™‚๐Ÿ‘๐Ÿผ

Cool thanks for info, i play drum & bass, jungle, reggae, dub, old dubstep. I would be very keen on seeing what the mouth extensions look like and whats involved? 

Im really new to all this so dont fully understand the graphs 100% yet but can see the figure being 4db higher so thats decent! 




Posted By: infrasound
Date Posted: 18 May 2020 at 9:21am
Upload your sketchup file, and I'll try and get something added in early this week Thumbs Up

Should match your genres well, lots of 35-50 content in there


Posted By: Jack1991
Date Posted: 18 May 2020 at 9:37am
Ok mate cheers will do when i get home on laptop. Thanks for that ๐Ÿ‘๐Ÿผ

My Thams are correct size on Sketchup but everything else was just roughly to size to get an idea of look. As sketchup was new to me too when starting this project.


Posted By: jammin75
Date Posted: 18 May 2020 at 11:56am
great work Thumbs Up

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feel the vibes !!!   "Who Feels it Knows it"            Strong like Lion              


Posted By: Jimi Handtrix
Date Posted: 20 May 2020 at 8:14pm
Many thanks for the detailed walk-through! I'm currently building a similar setup (I have 1x Cubo15 built and wired), and just finished the top-section today (with 2x 1" drivers + horn flares). I'll also be running from a Pioneer GM-D8704 and a miniDSP. There are a lot of points explained well here which I had been wondering about (and also the idea of angling the mid and top sections has given me some food for thought) - so thanks for that! 


Posted By: Jack1991
Date Posted: 24 May 2020 at 9:45am
No problem Jimi im glad its helped out. Look forward to seeing the build! ๐Ÿ™‚๐Ÿ‘๐Ÿผ


Posted By: Jack1991
Date Posted: 26 May 2020 at 8:16pm
First time testing it outdoors today. It sounded a lot louder and clearer. Which surprised me as i imagined inside my garage it would have been significantly louder??




Posted By: APW
Date Posted: 26 May 2020 at 9:08pm

I noticed several years ago my 4 Thams work much better in larger halls or outdoors, they donโ€™t seem to do so well in smaller spacesโ€ฆ I have no idea why this is but itโ€™s something Iโ€™ve noticed in several small venues.

 Iโ€™ve been doing an annual event for the same client for the last 10 yearsโ€ฆ for about 200 people outdoors (large garden party), 4 Thams makes the tiles rattle on clients out houses without being driven hard!!

I have another annual event thatโ€™s in a marque in the middle of a field for a tennis club; we get complaints about the bass from about ยฝ mile away, again without driving them hardโ€ฆ..

โ€ฆ.Yet in a small pub about a mile from home (that should be no trouble at all) we have to drive them fairly hard to get any decent bass out of them.   



Posted By: Jack1991
Date Posted: 26 May 2020 at 9:23pm
Strange yeh thats exactly what happened here! Im glad you said the same though APW as i was wondering if it was in my mind haha. 




Posted By: Peter Jan
Date Posted: 26 May 2020 at 9:51pm
First thing that comes to mind, could be the placement in this relatively smaller spaces.
It's not so difficult to have (sub)bass cabs positioned from walls at a distance around 1/4th of a wavelength in it's frequency range, making for some serious dips in response by destructive cancellations. SPL dips and peaks vary also depending on where you are in the space.
This situation is less possible in outdoor situations, where there probably aren't any nearby, hard surfaces for low frequency waves to bounce off from and create those destructive and constructive interferences.



Posted By: infrasound
Date Posted: 27 May 2020 at 7:34am


Here is the basic principle. 

Bare minimum structure on the left. On the right is an example of 4xTHAM 12 with extensions, stacked differently and with example bracing. You could probably manage to make them stack inside each other for storage with some creative thinking.


In answer to your PM:

They are less popular in commercial PA as take up a relatively large amount of volume - where more cabinets or amplifier power is usually used and horn loaded designs are normally second to reflex. 

There are a couple of examples on here, the last I saw was for a solar powered system, they're a more popular concept on DIYaudio. Seen them used at St. Pauls Carnival by Void - great fun in a narrow street...



Posted By: Jack1991
Date Posted: 27 May 2020 at 9:24am
Oh okay that makes sense then Peter Jan. Im glad that outside does sound better as it will mainly be used outdoors.


Thanks too infrasound for the info on those! Initially i wasnt sure but the more i look the more i like the idea! I think ill give it a go in future and see how it sounds. Ill have to find them pictures of void using them at st pauls carnival would love to see it in real life! ๐Ÿ˜€๐Ÿ‘๐Ÿผ


Posted By: infrasound
Date Posted: 27 May 2020 at 9:28am


Here you go, fancy bracing is optional


Posted By: Jack1991
Date Posted: 27 May 2020 at 9:53am
Oh sound thats decent! The fancy bracing does make it look a lot more appealing! Does the bracing need to be certain angles or edges put on them or no?

Also is the mouth extension permenantly attached to the tham or it just temporarily placed up against it sort of thing.


Posted By: infrasound
Date Posted: 27 May 2020 at 10:01am
So long as it's "in line" with the direction of the sound (wavefront) its OK. Take a look at other horn loaded designs and you'll get the idea.

In terms of requirements:

It needs to be sealed to the unit, something like your draught foam will be fine. They also would ideally be rigidly mounted and fairly rigidly made. I would advise they were removable, maybe latched onto the front when needed - otherwise are going to be super awkward to move.

You have quite a bit of leeway with the design of them to be honest - they aren't too sensitive to geometry changes and you can do any kind of weird & wonderful bracing you fancied


Posted By: APW
Date Posted: 27 May 2020 at 10:26am

Originally posted by Peter Jan Peter Jan wrote:

.....
It's not so difficult to have (sub)bass cabs positioned from walls at a distance around 1/4th of a wavelength in it's frequency range, making for some serious dips in response by destructive cancellations. SPL dips and peaks vary also depending on where you are in the space.
.....

I'm well aware about 1/4 wave placement, however one of the places I have problems with the Thams are placed in 2pi (against a wall) and in another venue they are in pi/2 (in a corner) plus I have no issues using reflex cabs in exactly the same locations....

Infrasound: I'm liking the idea of the extensions...Please donโ€™t give me any more ideasโ€ฆ my wife will go mad again!!!



Posted By: Jack1991
Date Posted: 27 May 2020 at 2:33pm
Cool okay thanks infrasound i will look into these then. And see if i can think of ways to temporarily fix them solid to the Thams.

APW what drivers are you using with your Tham12s out of interest?


If in future i was going to upgrade or change my Tham driver i guess i can only fit ones with the same Bolt mounting positions, or has someone got a niffty way to get around that??


Posted By: infrasound
Date Posted: 27 May 2020 at 2:49pm
https://forum.speakerplans.com/th-unity-horn-24v-solar-sound-system_topic63191_page11.html%20" rel="nofollow - https://forum.speakerplans.com/th-unity-horn-24v-solar-sound-system_topic63191_page11.html

Phil has a nice example here of the extensions


Posted By: APW
Date Posted: 27 May 2020 at 4:21pm

Iโ€™m using the Beyma 12lx60v2โ€ฆ Donโ€™t get me wrong, Iโ€™m extremely pleased with my Tham 12s they just seem to prefer larger rooms or outside.

I also have a pair of small 2x12 reflex cabinets for smaller venues that the Thams donโ€™t work so well in and a stack of 18โ€ loaded reflex cabinets for genres  that have a lot of LF/sub that the Thams cannot reproduceโ€ฆ 99% of the time the little Thams do the job just fine.  



Posted By: studio45
Date Posted: 27 May 2020 at 5:32pm
Originally posted by Jack1991 Jack1991 wrote:

Cool okay thanks infrasound i will look into these then. And see if i can think of ways to temporarily fix them solid to the Thams.

APW what drivers are you using with your Tham12s out of interest?


If in future i was going to upgrade or change my Tham driver i guess i can only fit ones with the same Bolt mounting positions, or has someone got a niffty way to get around that??

You need Clamps! Good steel ones, not the plastic snappers. Bluearan sell them.

From my experience with the MTH30 which is similar, it will wring lots of bass out of any 12" driver - even quite low powered, cheap types - you can save some weight that way, at the expense of power handling and maximum output of course.


-------------
Studio45 - Box Builder Commotion Soundsystem -Mobile PA


Posted By: Jack1991
Date Posted: 27 May 2020 at 5:43pm
Cheers again for the answers guys!

I think i will leave the added horns for now and probably next will be the 2x cubo kick 12's and dsp. Then the horns can be just a quick side task to do one day in the future.

Only part of me is thinking i wish i used better drivers for the Thams but i dont know if its even worth it as they wont be driven very hard only 150w rms amp power each. Dont get me wrong im not dissapointed with how they sound. I think they sound amazing much better than expected. I just think if these cheap ones sound this good. The more expensive ones must sound incredible!
What do you guys rekon? Again though i suppose im restricted by the bolt holes now unless is there a way around this for future reference?


Posted By: infrasound
Date Posted: 27 May 2020 at 7:05pm
The main advantage of a more expensive driver is increased output, either with power handling or displacement. Unless you want to drive it with more than 150w, little point in throwing money at them!


While a cubo kick in will add to transient response into the 100-250 passband, the THAM12s are already strong up to 200Hz as a general purpose low end. The sound will definitely improve, but you will be doubling up slightly. A DSP and a good fiddle will do wonders for the sound for the meantime. Big smile



Posted By: Jack1991
Date Posted: 27 May 2020 at 7:17pm
Originally posted by infrasound infrasound wrote:

The main advantage of a more expensive driver is increased output, either with power handling or displacement. Unless you want to drive it with more than 150w, little point in throwing money at them!


While a cubo kick in will add to transient response into the 100-250 passband, the THAM12s are already strong up to 200Hz as a general purpose low end. The sound will definitely improve, but you will be doubling up slightly. A DSP and a good fiddle will do wonders for the sound for the meantime. Big smile


Ahh sorry i ment the speakers are rated at 280w rms each. But they are getting 150w rms from the amp each. But cool yeh equally that answers my question perfect thanks man! I will be sticking with these๐Ÿ˜€๐Ÿ‘๐Ÿผ


Also i found them to sound best being crossovered at around 95hz they didnt seem too great above that really. Maybe again becuase that was when inside my garage. Do you think just adding a dsp would make a noticable difference then? (without the cubo kicks) If i had a dsp would i still use the passive crossovers from the mids to tops. Or do away with them? Im not quite sure how it all works with a dsp yet.


Posted By: infrasound
Date Posted: 27 May 2020 at 9:25pm
Should be fine up to 150Hz or so, but is of course dependant on crossover type, environment and personal preference..

Personally, my next step would be to get a DSP. I use mainly miniDSPs  http://https://www.minidsp.com/products/minidspkits/2-x-in-4-x-out" rel="nofollow - http://https://www.minidsp.com/products/minidspkits/2-x-in-4-x-out , but have heard good things about the Thomann unit  http://https://www.thomann.de/gb/the_t.racks_dsp_4x4_mini.htm" rel="nofollow - http://https://www.thomann.de/gb/the_t.racks_dsp_4x4_mini.htm . Grab a USB measurement microphone such as  http://https://www.minidsp.com/products/acoustic-measurement/umik-1#umikcalfile" rel="nofollow - http://https://www.minidsp.com/products/acoustic-measurement/umik-1#umikcalfile , REW  http://https://www.roomeqwizard.com" rel="nofollow - http://https://www.roomeqwizard.com  and a crate of beers  http://arborales.co.uk/arbor-beer/" rel="nofollow - http://arborales.co.uk/arbor-beer/ . 

Spend about a week fiddling and you'll learn a hell of a lot - and it'll sound 200% better. No need for another amp.


Posted By: Jo bg
Date Posted: 27 May 2020 at 10:27pm
Hi again 
Better drivers will not give you great improvement over decent ones if you  are not going to push them, maybe some hz of extension and better linearity but not comparable to adding two identical subs.
I would also avoid cubo kicks for this system in particular , although i use the 15 variant over my subs so I don't dislike the design.
But your subs already play in similar frequency region, adding other kicks with different design  and phase/timing  behaviour will just mess up things.
Adding 2 identical cabs will couple easier and better and will not require additional  processing channels And maybe even amps.
Usually on smaller and efficency focused  system  2 way  bass  is not a good idea.

Have you measured your system?Seems time to learn Rew or Smaart (90day demo this days) or find someone with software , mic and brain willing to spend sone time in the parking lot and measure it.
As you just learned listening in the garage won't give any useful information.
Probably your subs have a rising response, so finding and taming that peak with some eq or using the crossover slope wIll make them sound better, the more so at high level.
That and time align and limiting is the kind of things A dsp could do for you.
Look at something like the t racks 12v job on thomann, looks plenty and road ready , but i just read about it never touched it!




Posted By: Jo bg
Date Posted: 27 May 2020 at 10:28pm
Just wrote a poem but Infrasound post sums it up perfectly in the meantimeSmile


Posted By: Jack1991
Date Posted: 28 May 2020 at 7:13am
Thanks infrasound & Jo bg ๐Ÿ˜€

I will give the Cubo Kick 12s a miss then.  And will instead like you both said, just go down the DSP route. Then in future I could add 2 more Thams12s maybe. Does stacking multiple Thams add anything like it does with some subs?

I will start looking into all these and trying to learn them.

One last thing for now then. At the moment i have the mids and tops joined by passive crossovers, with 1 mid/top on 1 channel of the amp and the 2nd mid/top on another channel. If using a dsp i assume i would get rid of the passive crossover and join the 2x mids together on there own channel. And then the 2x tops together on there own channel, controlling the crossover points and Tops attenuation from the dsp, for best results. Is that correct?


Posted By: Shortrope
Date Posted: 28 May 2020 at 7:56am
I would keep the setup as is with the tops running stereo With the passive crossovers. Use the DSP to control the crossover points from Sub to tops, eq and possibly a bit of delay.
The ideal scenario would be to have five or six Amp channels and a six channel DSP. 
A pair for the tops, a pair for the mids and one or two for the Subs. 
That way you could very accurately setup and eq all the drivers. 



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My Tinnitus is coming along nicely!!


Posted By: infrasound
Date Posted: 28 May 2020 at 8:50am
I think you've lucked out a bit with all the help here LOL

Multiple subs always helps. I suspect that as you grow to understand the system through measuring and setting up, you'll realise that the rising response Jo mentions needs some EQ to sort it out. EQ is the easiest way to loose headroom and your amp will start running out of steam much earlier

 There are generally a few ways to combat this, and you'll need to choose later down the line:

1. Add more subs. This gives more sensitivity (I posted the graphs earlier!) and power handling
2. Add more amplifier power
3. Meatier drivers (with amplifier power)
4. Change your subs to ones with more natural sensitivity in your problem regions
5. Add horn extensions
6. Some combination of above




Posted By: Phil B
Date Posted: 28 May 2020 at 9:24am
Originally posted by infrasound infrasound wrote:

So long as it's "in line" with the direction of the sound (wavefront) its OK. Take a look at other horn loaded designs and you'll get the idea.

In terms of requirements:

It needs to be sealed to the unit, something like your draught foam will be fine. They also would ideally be rigidly mounted and fairly rigidly made. I would advise they were removable, maybe latched onto the front when needed - otherwise are going to be super awkward to move.

You have quite a bit of leeway with the design of them to be honest - they aren't too sensitive to geometry changes and you can do any kind of weird & wonderful bracing you fancied


Hi. If you go down the Barn Door route ....I've posted this a few times...



The doors are still going strong. We have to re-seat the clamps and loctite the bolts every year but the benefits and visuals are worth it.

We are thinking about some kind of extensions for our Keystone subs but that is a tricky one !

The link to what we've been getting up to with tapped horns, 24v and Sunshine has been posted already.

Nice build BTW

.p.

-------------
Mostly harmless.... except if catering is shut.

Solar Sound System Shennanigans.. http://diyhifi.biz/" rel="nofollow - http://diyhifi.biz/


Posted By: APW
Date Posted: 28 May 2020 at 9:36am

Jack, what exactly do you feel the system is lacking?

Is it lacking bass, is it โ€œShoutyโ€ in the mid-range, is it lacking top-end sparkle?



Posted By: Jack1991
Date Posted: 28 May 2020 at 11:53am
Thanks for all the replies people! I will have a proper read when im home from work.

APW - I don't feel its lacking anything to be honest, im really happy with it. But again i am completely new to this sort of thing, so i would imagine someone experienced would completely disagree with me. I was mainly just looking to build more speakers like the cubo kicks, as i found it fun building the rest of it. Or if theres improvements i can make in order to make big improvements on what i have now (like adding a dsp) then im willing to learn and then do these things.


Posted By: Jack1991
Date Posted: 29 May 2020 at 5:03pm
Have been having a good read of the replies today and also thinking about what to do next and what to build in the meantime. I think ill start making 2 more Thams just for the meantime whilst trying to learn the Dsp stuff

Also I know you guys said about the cubo kicks not working great with the Thams as the Thams play quite high so this is purely out of interest. If you were to crossover from the Thams to the Cubo Kicks lower would that make them work well together? Or does it not work like that?


Posted By: infrasound
Date Posted: 29 May 2020 at 5:15pm
They both play the same frequency band well. You'll have more problems with phase and crossovers in the region for no real benefit. It's still just increasing the type of speakers for the sake of it - only do it if you want the visual effect.

As I mentioned, once you start measuring, you'll likely want lower bass at higher SPLs given your music preferences. More THAMS or extensions (cough cough) with a DSP would be a good way to solve this!

Main priorities for now IMO: Beers, tunes, DSP and measurement microphone!


Posted By: Jack1991
Date Posted: 29 May 2020 at 5:26pm
Ah okay perfect yeh i understand now. Yeh the look of the cubo kick is what drew me in, i will give it a miss but was hoping i found a solution haha!

Hahaa that sounds like a perfect plan! The beers are sorted just need to buy that dsp and measurment microphone! I will buy them within the next couple of weeks and start measuring. Is there any special way that needs to be done. From what i read so far everyone says in the garden or in a open outdoor space?


Posted By: Jack1991
Date Posted: 29 May 2020 at 6:36pm
Also i didnt realise how expensive usb measurement microphones are! And there only seems to be 1 to choose from. The minidsp branded one. I found other ones for around £30 on thommann but there not usb. 

Is the microphone essential or can i do near enough just as good a job with just the dsp?


Posted By: Peter Jan
Date Posted: 29 May 2020 at 6:38pm
Originally posted by Jack1991 Jack1991 wrote:

Is there any special way that needs to be done. From what i read so far everyone says in the garden or in a open outdoor space?


You could measure indoor if that space is large and measuring microphone close (1m) to box/system you are measuring. A typical sized garage won't do as the walls/ceiling/etc are too close and will alter the respons you measure, because the walls/ceiling/hard floor reflect waves and the micrphone picks those up too.


Posted By: Jack1991
Date Posted: 29 May 2020 at 7:35pm
Ah okay cool thanks Peter Jan. I think my garage will be a bit too small then.
So even outdoors measure from 1m away and 1m high?


Posted By: Peter Jan
Date Posted: 29 May 2020 at 8:00pm
1m away and ~central on axis with the measured cab is the reference for SPL/sensitivity measurement (how much SPL for 1W and at 1m ), but for respons measuring, you can place the microphone at 2-3-4m distance, because it is about respons, not SPL. I do all respons measurements at 3 m, but to each his own really. Height more or less central to the cab you want to measure for starters, but later on you can check hor. and vert. off-axis respons too. But first on-axis respons has to be good, later on you can check at different H and V angles.


Posted By: Jack1991
Date Posted: 29 May 2020 at 8:14pm
Oh okay you measure each cab individually then... I need to do more research i think. Thanks again man! 


Posted By: Peter Jan
Date Posted: 29 May 2020 at 8:21pm
The system you have now is modular, so you can measure them each to see what they do responswise, so later on you can recognise things when you measure it all together. For instance a dip occuring somewhere, while the individual parts don't have that dip on their own, is an indication that the combination has an issue, not an individual component.


Posted By: infrasound
Date Posted: 29 May 2020 at 8:50pm
You can get a non USB one, but bear in mind you'll need a soundcard with input and won't be calibrated. USB tends to be easier and less faff in general

I would recommend getting one, it's a worthwhile investment IMO


Posted By: Jack1991
Date Posted: 30 May 2020 at 11:42am
Cool thanks again for the info guys ๐Ÿ˜€๐Ÿ‘๐Ÿผ

So once i have a dsp and microphone and have set it all up correctly. Or to the best of my ability. Does that then mean it will sound better no matter where i position the speakers? For example say i do the microphone set up in my garden. Then i decide to take the speakers to a friends house and set them up in his living room. They will sound better than before microhone set up. Or is it everytime you move them they need re-setting? Hope this makes sense.


Posted By: infrasound
Date Posted: 30 May 2020 at 12:13pm
Originally posted by Jack1991 Jack1991 wrote:

Cool thanks again for the info guys ๐Ÿ˜€๐Ÿ‘๐Ÿผ

So once i have a dsp and microphone and have set it all up correctly. Or to the best of my ability. Does that then mean it will sound better no matter where i position the speakers? 

Yes firstly - you set it up to be flat, phase friendly and sounding as you want outdoors

 For example say i do the microphone set up in my garden. Then i decide to take the speakers to a friends house and set them up in his living room. They will sound better than before microhone set up. Or is it everytime you move them they need re-setting? 

When you next place speakers indoors, you'll have a whole ton of room interactions happening. You can choose to adjust for these, or not. Many don't bother - or just adjust by ear at each new location

 Hope this makes sense.

Setting it up for flat outside is the most important. If the stack behaves well outdoors, then the inside interactions will have the least effect. 

Say you have a huge mid hump of +6dB at 1K6 from a incorrect crossover. If you did not fix this outside, then took it into a room that accentuated it by 3dB - then you'd have a whopping 9dB boost indoors. Which would sound fairly nasty!


Posted By: Jack1991
Date Posted: 30 May 2020 at 12:30pm
Ahh okay cool perfect that makes sense now cheers! ๐Ÿ˜€๐Ÿ‘๐Ÿผ

I have been watching loads of videos about it all and i understand what the outcome is thats wanted now, getting that flat response, but how they get to that is still what im trying to understand. Goes straight over my head at the moment the terminology etc, its a lot to take in.


Posted By: Jo bg
Date Posted: 30 May 2020 at 2:22pm
Indoor adjustments are valid only for  that particular room stacked in that position and configuration, and mic postion too, so don't worry too much.
Go outside , possibly on concrete, possibly ten or more meters from any building or surface.
You could use ground measurement for the bass up to a few hundred hertz to avoid groundbounce.  Google that. Difficult to use on higher frequency so rise your mic for that. Measure in a few spots  to compare trends, if a you have a peak on axis but on the majority of the useful dispersion it's not there you may want to leave it, averaging multiple mics posituon works if sofware allows.
Don't obsess on equing everything super flat, or about sharp thin dips that will not be audible, and try to use more subctractive eq than boosts.
Usually dsp have an input eq and per output eq.
You can do the alignment and general per driver eq on the output section and don't mess with it any longer, then use the input section for situation eq, like taming one or two nasty resonancies in the room, maybe you want to shelf the highs or do other adjustments without messing with the system basic tuning



Posted By: Jo bg
Date Posted: 30 May 2020 at 2:27pm
Measuring will take some learning curve but will teach you a lot about sound and rooms. Post your measurements here with picture of the measurements settings ( this is very important ) and you will learn a lot from your first mistakes.
Try to get hold of a mic with individual correction curve if possible(linked to serial number, not general for the product).


Posted By: Jack1991
Date Posted: 31 May 2020 at 3:22pm
Cool okay thanks Jo bg ๐Ÿ™‚๐Ÿ‘๐Ÿผ

Right few things im unsure of and could use some help please. And just checking im correct on some stuff too.

So the amplifier has 4 rca inputs (1 per channel) Channel 1 is for 1 mid/top. Channel 2 is for the 2nd mid/top, then channels 3&4 are bridged which the subs are on linked in parrallel. So when i go from the dsp output (which is 1/4 jack) id go output 1, 1/4 jack to rca on channel 1 of the amp. Same for output 2 to channel 2 on amp. Then output 3 would i need to get a 1/4 jack to TWIN rca to go into channels 3 and 4 on the amp? Or just go to 1 channel?

Secondly once the dsp is wired correctly do i turn off the lpf and hpf on the amplifier and just use the filters within the dsp instead? Also do the gain settings on the amplifier still get used like normal or do i turn this to there lowest positions and use the gain within the dsp instead?

Thirdly, at the moment the mids and tops are joined by a 2.5k passive crossover each. Would i be best leaving that in and wiring as said in question 1 or would it be better for me to remove the passive crossovers and then wire the Tops to there own channel in parrallel, then the mids in parrallel to there own channel instead. So i could then change the crossover point and other things more freely?

Final question for now at least. A bit vague i know, but do you think adding a dsp and setting it all up correctly with a microphone be noticeably better to a complete newbie like myself, only asking as it will be mainly used just for fun in fields or parks with a group of drunken mates and probably a few people who join in. I just want the cost of the microphone and dsp to be justified by a decent noticeable difference in sound. Or is it the sort of thing only a audiophile would notice?

Cheers again guys ๐Ÿ˜€๐Ÿ‘๐Ÿผ


Posted By: Jack1991
Date Posted: 24 June 2020 at 3:12pm
UPDATE:

Little update for now but should have a decent update on friday. 

With the weather so nice decided to begin making  2 more Tham12s in the garden today. Then when i go to buy the drivers i will probably get a dsp then at the same time. I need to wait till payday though and see.




Posted By: Jack1991
Date Posted: 25 June 2020 at 10:29pm
Finally got the grilles on the subs! 


Now to build 2 more tham12s... 


Posted By: infrasound
Date Posted: 26 June 2020 at 9:16am
Looks real slick!

Re. The microphone / DSP. Both will contribute significantly to the sound, and will be noticeable (drunk or not drunk) - no 'audiophile' ears needed Thumbs Up

Worth noting though, that a DSP takes a little time & microphone needs more time again to get the most out of them.

Neither are an instant fix, but do unlock the full potential - if you have the time and inclination to learn!


Posted By: Jack1991
Date Posted: 26 June 2020 at 9:29am
Thanks infrasound! Im pleased with it so far.

Thats good with the dsp too. I think im sold on it now then! Im going to have a lot of newbie questions though trying to learn it. 

Do you still use the lpf/hpf on the amplifier? Or should they be turnt off? And also the gain on the amplifier is that still used?


Posted By: infrasound
Date Posted: 26 June 2020 at 9:39am
The hpf/ lpf will be made redundant on the amplifier by the DSP. Best to just disable.

In terms of gain on amplifier this is the normal approach:

Turn all gains up to max. on the amplifiers. This stops anything being turned up 'beyond' where its supposed to (especially if you have limiters on the DSP), and makes it easy to balance system as there's no "turn it to around 12 o'clock for the right level"

It may well be the case you have extra noise on the outputs (maybe in HF) so you may need to dial it down a bit on amplifier to accommodate. Of course you may run into issues with turning up 'too far', not good times for compression drivers and/or ears.


Posted By: Jack1991
Date Posted: 26 June 2020 at 12:14pm
Cool thanks again infrasound. That all makes perfect sense. 

I assume on the dsp there is attenuation aswell? So i can bring the tops down 12db as ill be running the tops joined parallel on there own channel rather than on the passive crossover(which had the resistors on to bring it down) with the mids. Then ill have the mids joined parallel and on there own channel too.


Posted By: infrasound
Date Posted: 26 June 2020 at 2:34pm
Yes, gains and routing are all handled in there.

And yes, if you have an amplifier channel for the mids and an amplifier channel for the tweeters then you'll be able to get rid of the XO. (Of course it'll be running in mono). Means you can time align, shift / change type of XO, EQ, get more power handling, etc


Posted By: Jack1991
Date Posted: 26 June 2020 at 3:00pm
Cool perfect! Sounds good, i will start reading up on it a bit more soon then to try and learn the basics before getting it. Thanks again man


Posted By: Jack1991
Date Posted: 26 June 2020 at 6:51pm
Heres my side project ive been building in the meantime.

Sack Truck Sounds!

First outing today it sounds pretty decent.




Posted By: Jack1991
Date Posted: 27 June 2020 at 7:08pm
Oh yeh also i ment to ask this the other day. When stacking multiple tham subs, I know you said it increases SPL. But does it also make them play slightly lower too?


Posted By: infrasound
Date Posted: 27 June 2020 at 7:34pm
By a small amount.. However, with the EQ in the DSP, you'll be able to pull +6dB more LF out of them with the extra headroom.

If you wanted to go much lower - you'd either want to look at extensions or lower tuned subs

Sack truck sounds looks bang on Cool


Posted By: Jack1991
Date Posted: 27 June 2020 at 7:51pm
Ah okay is it just scoops then that seem to drop a good bit lower when adding multiples?

Also thanks man! It was decent. I will be taking it out again soon properly though next time! 


Posted By: concept-10
Date Posted: 27 June 2020 at 8:04pm
Originally posted by Jack1991 Jack1991 wrote:

Ah okay is it just scoops then that seem to drop a good bit lower when adding multiples?

Also thanks man! It was decent. I will be taking it out again soon properly though next time! 

Front loaded horns drop lower in multiples, reflex bins do also, tapped horns are a bit of an odd ball when it comes to coupling, I have lots and you will get a small amount of low extension but nothing like a FLH, as for scoops ? who cares Wink


Posted By: Jack1991
Date Posted: 27 June 2020 at 8:21pm
Ah okay cool thanks concept! What is a good example of a front loaded horn? I did think all horns were the same i didnt realise there were sub genres of horns 

Haha ah yeh ive heard of the scoop vs horn thing. In the middle of building 2 more thams anyway so hopefully in a few weeks i can test out the 4 together! 


Posted By: concept-10
Date Posted: 27 June 2020 at 9:10pm
Martin 215 is a good example of a FLH, the Thomann drivers you are using in your Thams are very under rated in my opinion, we have them in some of our 12" Tapped horns and they are good into the high 20s, in fact we high pass them at 22hz, it is a much bigger cab than the Tham 12 though. You will be impressed with four Tham 12s, maybe a couple of hz lower but a lot louder and a lot more impact, really impressed with what you have achieved so far, keep up the good work. :) 


Posted By: Jack1991
Date Posted: 27 June 2020 at 9:40pm
Cool i will search them now. Glad you rate the Thomanns too, a good few forums i have read all seem too like these thomann drivers. I have nothing to compare them to but they are better than i expected for the money. Im real excited to get all 4 Thams going!

What 12" tapped horns you using? Id be interested in seeing the setup.

Thanks too, i have learnt alot from you guys. I really appreciate all the help! ๐Ÿ˜€๐Ÿ‘๐Ÿผ


Posted By: munkey
Date Posted: 27 June 2020 at 10:23pm
Which of the thomann drivers would you use? The w or the a?  

-------------
the midtops!


Posted By: infrasound
Date Posted: 27 June 2020 at 10:25pm
I believe the small mouth area of TH is partially to fault for lowering LF cutoff.

Plus, they are rarely used in enough quantity to force much LF pattern control.


Posted By: Jack1991
Date Posted: 27 June 2020 at 10:28pm
Originally posted by munkey munkey wrote:

Which of the thomann drivers would you use? The w or the a?  

I am using the 12-280-W

I heard the 12-280-A can be used for the cubo kick 12


Posted By: Jack1991
Date Posted: 27 June 2020 at 10:29pm
Originally posted by infrasound infrasound wrote:

I believe the small mouth area of TH is partially to fault for lowering LF cutoff.

Plus, they are rarely used in enough quantity to force much LF pattern control.

Ah ok cool so the barndoor extensions would add lower extension then?


Posted By: infrasound
Date Posted: 27 June 2020 at 10:43pm
They mainly do it by a different mechanism (increasing path length)

Just to make it more complicated Wink


Posted By: Jack1991
Date Posted: 27 June 2020 at 10:45pm
Haha ah ok another complicated speaker thing i need to learn then 


Posted By: studio45
Date Posted: 28 June 2020 at 3:07pm
In my experience the biggest thing you will notice when using tapped horns is they get much, much louder when fired into a corner, than other bins. I've successfully filled a 10x15x3m bar with loud, deep bass using just one 12" tapped horn aimed into a corner from 3 feet back, loaded with an old McKenzie 300 watt driver, on a 500 watt amp channel. 

The small size of most TH bins makes this easy to do in real world situations. I suppose the full corner loading makes up for the lack of mouth area on the bin itself.

Of course it's not really relevant when playing outside, unless you're next to a building.


-------------
Studio45 - Box Builder Commotion Soundsystem -Mobile PA


Posted By: Jack1991
Date Posted: 28 June 2020 at 4:46pm
Oh cool i will give this a try in the garage see how it goes! Thanks man

It also seems having the rig on a pallet sounds better than having it on the floor. Is there a reason for this too or just coincidence?


Posted By: Jimjimjimmer
Date Posted: 30 June 2020 at 10:39am
Another nooby question Smile.. How have you routed the speaker cable through your Thams? Do you have speakons on the back and the cable running up through the horn or another way?



Posted By: APW
Date Posted: 30 June 2020 at 11:20am

Most builders drill a small tight fitting hole for the cable(s) roughly in one of the locations shown in red below, just make sure itโ€™s airtight (use corking or neutral curing silicon) once the cable is fitted:

 

Speakon connectors can be fitted anywhere on the rear panel where there is room.

Personally I wrap the cable(s) in cloth โ€œloomโ€ tape (tesa 51608 or similar), this stops them vibrating against the inside of the horn.





Posted By: Jack1991
Date Posted: 30 June 2020 at 12:09pm
Originally posted by Jimjimjimmer Jimjimjimmer wrote:

Another nooby question Smile.. How have you routed the speaker cable through your Thams? Do you have speakons on the back and the cable running up through the horn or another way?


I went through the back straight level height to where the connectors on the speaker driver are. And used a double speakon socket plate. And then i used Black "the dogs bollocks" (yes its actually called that) says it cures in 24 hours. But it was probably 3 days anyway before i had a chance to fit the drivers. 



I think they say some sealants like silicone, the fumes can eat away at the speaker or something like that.

I twisted then dabbed a bit of solder on the ends of the speaker cable too. Made it alot easier getting them into the speaker fittings as its tight inside and you cant can what your doing.


Posted By: APW
Date Posted: 30 June 2020 at 12:39pm
Originally posted by Jack1991 Jack1991 wrote:


....
I think they say some sealants like silicone, the fumes can eat away at the speaker or something like that.


Yep.... Standard โ€œAcetoxyโ€ silicone sealants release acetic acid (which smells a little like vinegar) as they cur, this can attack the materials used in the speaker, โ€œNeutral cureโ€ silicone products reduce or eliminate the production of acetic acid while curing and are safe to use in speaker building.



Posted By: Jack1991
Date Posted: 30 June 2020 at 12:53pm
Ah right cool interesting stuff APW. I did always wonder what the horrible vinegar smell was in silicone. That stuff i used luckily didnt smell of anything hopefully should be sound 


Posted By: Jimjimjimmer
Date Posted: 30 June 2020 at 3:55pm
Thanks alot ๐Ÿ™‚


Posted By: Jo bg
Date Posted: 30 June 2020 at 7:08pm
usually silicones for mirrors are neutral cure FYI



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