Go Back   Home > Forums > >

Multi-Way Conventional loudspeakers with crossovers

DIY Marble Monitor
DIY Marble Monitor
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools
Old 18th March 2020, 10:47 AM   #1
bigbluecoconut is offline bigbluecoconut
diyAudio Member
 
Join Date: Jun 2017
Default DIY Marble Monitor

Hello fellow DIYers
I proudly present my 100% diy nearfield Monitors.
After nearly 2 years of prototyping, designing and testing they are ready.
My goal was to design more or less cheap active nearfield speakers.
I compared them to Genelec 1029a (which i really like),
and they performed better then expected, they sound awesome.

They are powered by an 50VA 25V torodial transformer, with an added
5V winding for the DSP.
They are bi-amped with two self oscillating class-D Modules,
and controlled by an ADAU1701.
Woofers are 5" Faitalpro 5FE120, amazing and cheap (<30€).
Tweeters are 1.3" soft dome LAVOCE TN131.00 (<15€).
I also added an extra switch, i call it "HIFI mode", which boosts the lows
and the highs.

The front is made of 20mm South-Tyrolean Marble, wood is cherry,
and th br-channels are made of mdf.
Since i got the marble and wood for free the total cost for 1 speaker was
aprox. 80€ (working hours included <5000€ )

Since i dont have access to an anechoic room, i used the silence outside due
to the corona quarantine here in Italy to measure and adjust the speakers.
The neighbours probably got crazy after 2 hours of sweeps .

Here are some PICs:

DIY Marble Monitor-1-jpg
DIY Marble Monitor-4-jpg
DIY Marble Monitor-7-jpg
DIY Marble Monitor-8-jpg
DIY Marble Monitor-9-jpg

The measured frequency response after adjunsting with the DSP:
DIY Marble Monitor-11-png

Maybe i will replace the transformer with a flyback SMPS, and place everything on one PCB...
Lets see
Attached Images
File Type: jpg 1.jpg (255.5 KB, 571 views)
File Type: jpg 3.jpg (459.2 KB, 65 views)
File Type: jpg 4.jpg (269.8 KB, 620 views)
File Type: jpg 6.jpg (196.5 KB, 74 views)
File Type: jpg 8.jpg (483.6 KB, 659 views)
File Type: jpg 9.jpg (294.1 KB, 637 views)
File Type: png 11.png (58.3 KB, 625 views)
File Type: png 12.png (83.0 KB, 83 views)
File Type: jpg 7.jpg (382.0 KB, 669 views)
  Reply With Quote
Old 18th March 2020, 11:24 AM   #2
adason is offline adason  United States
diyAudio Member
 
adason's Avatar
 
Join Date: Nov 2004
Location: Maryland
Nice work. Can you post series of off axis measurements? 0, 10, 20, 30, 40 degrees?
  Reply With Quote
Old 18th March 2020, 11:36 AM   #3
celef is offline celef
diyAudio Member
 
Join Date: Nov 2012
Very nice look, and light in the ports must look good when its dark. That waveguide to tweeter looks deep, any issues? You should increase measurement resolution to at least 1/6 octave
  Reply With Quote
Old 18th March 2020, 11:39 AM   #4
celef is offline celef
diyAudio Member
 
Join Date: Nov 2012
It would be nice if ports turned red if in danger for overload, blue when cold and green for normal use and yellow when levels just started to get high
  Reply With Quote
Old 18th March 2020, 12:56 PM   #5
bigbluecoconut is offline bigbluecoconut
diyAudio Member
 
Join Date: Jun 2017
Thx, the ports are just beatuful in the dark, because the light shines a bit through the marmor and makes it glow like its on fire.
I didnt make any off axis measurements for 3 reasons:

1: I am always sitting in the Sweet Spot when i am mixing
2: I didnt wanna disapoint myself (bc that waveguide is really deep like u saw) so probably a problem off axis.
and i dont wanna grind this marble again
3: I dont have proper measurement equiptment to make a ideal measure.

Here is the fr with 1/12 smoothing:
But i cant say how much comb filter effect comes from walls, and ground outside.
DIY Marble Monitor-final-1-12-png
Attached Images
File Type: png Final 1.12.png (72.2 KB, 575 views)
  Reply With Quote
Old 18th March 2020, 02:31 PM   #6
grahamgraham is offline grahamgraham  United Kingdom
diyAudio Member
 
grahamgraham's Avatar
 
Join Date: Oct 2016
Location: London
Nice work!

I think a little look at off-axis is a good idea anyway, since you have used a DSP you can make some accounting for this in the crossover (getting a balance if there is a null or bunching up) though, I appreciate you are using on-axis it is always good to know

The 1029a is my favourite speaker (that I've heard) and I've owned a few 1029a units in my time, the modern class-d Genelecs don't seem to measure up IMO though I haven't heard the latest biggest and baddest ones of late.

Which DSP board did you use?

I will definitely take you recommendation and try the Faital and La Voce drivers.

Last edited by grahamgraham; 18th March 2020 at 02:59 PM.
  Reply With Quote
Old 18th March 2020, 02:42 PM   #7
bigbluecoconut is offline bigbluecoconut
diyAudio Member
 
Join Date: Jun 2017
Its also a diy board by myself
  Reply With Quote
Old 18th March 2020, 04:07 PM   #8
xrk971 is offline xrk971  United States
Got Foam?
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC (Virginia)
DIY Marble Monitor
That looks great. Very nice looking. I think Perceval has some speakers made from granite. All walls and not just the baffle. Marble looks very pretty though. You could make some mean waveguides with this stuff I bet. With elbow grease and hand tools - anything can be done. Just look at Michaelangelo’s David

You can buy a 50w or 100w Class D amp with the ADAU1701 built in. Just use AD’s free SigmaStudio DSP software suite to program it. Making a DSP Class D powered active monitor has never been easier (and cost effective) for the DIYer.

Dayton Audio DSPB-250 2x50W Class D Audio Amplifier Board with DSP

Or use these with your own amp:

Dayton Audio DSPB-K DSP Kernel Board and DSPB-KE Kernel DSP Expansion 2-In 3-Out

Dayton Audio DSPB-ICP1 In-Circuit Programmer USB
__________________
XRKaudio Store // Manufacturer’s Forum

Last edited by xrk971; 18th March 2020 at 04:11 PM.
  Reply With Quote
Old 18th March 2020, 07:21 PM   #9
454Casull is offline 454Casull  Canada
diyAudio Member
 
Join Date: Jan 2004
Location: Toronto, ON, Canada
Quote:
Originally Posted by xrk971 View Post
You could make some mean waveguides with this stuff I bet. With elbow grease and hand tools - anything can be done. Just look at Michaelangelo’s David
Yeah, but he didn’t have to follow a 3D model.
  Reply With Quote
Old 19th May 2020, 11:11 AM   #10
bigbluecoconut is offline bigbluecoconut
diyAudio Member
 
Join Date: Jun 2017
Quote:
Originally Posted by xrk971 View Post
That looks great. Very nice looking. I think Perceval has some speakers made from granite. All walls and not just the baffle. Marble looks very pretty though. You could make some mean waveguides with this stuff I bet. With elbow grease and hand tools - anything can be done. Just look at Michaelangelo’s David

You can buy a 50w or 100w Class D amp with the ADAU1701 built in. Just use AD’s free SigmaStudio DSP software suite to program it. Making a DSP Class D powered active monitor has never been easier (and cost effective) for the DIYer.

Dayton Audio DSPB-250 2x50W Class D Audio Amplifier Board with DSP

Or use these with your own amp:

Dayton Audio DSPB-K DSP Kernel Board and DSPB-KE Kernel DSP Expansion 2-In 3-Out

Dayton Audio DSPB-ICP1 In-Circuit Programmer USB


I made my own version
ADAU1701 + TPA3116
Click the image to open in full size.
Can be used as stereo amp, or 2 way with balanced in.
on my version just 4 GPIO´s are accessable because i dont need more.
Only problem, i placed a 25Mhz quartz instead of 12.288 MHz.
but i already replaced them.
Boards are made and assembled by JLCPCB, price ~13€ per piece (without shipping)
Much cheaper than the parts express version.
  Reply With Quote

Reply


DIY Marble MonitorHide this!Advertise here!
Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
marble enclosures? tmblack Multi-Way 24 25th February 2005 07:30 AM
satellites for marble sub Artmaster Multi-Way 0 15th November 2004 12:17 PM
working with marble karma Everything Else 6 8th September 2004 10:54 AM
marble subwoofer Artmaster Swap Meet 2 1st July 2004 04:15 PM
marble?!! 91TB78 Everything Else 8 13th November 2002 04:39 PM


New To Site? Need Help?

All times are GMT. The time now is 06:39 AM.


Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 14.29%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2021 DragonByte Technologies Ltd.
Copyright ©1999-2021 diyAudio
Wiki