Jump to content

Deep End DIY - My first speaker project


Recommended Posts

So, something turned up the other day.  Whatever could it be for?  A Christmas project perhaps...

 

 

12 sheets of 32mm MDF 1200mm x 2400mm

 

 

post-139669-0-36630100-1418974688_thumb.

  • Like 9
Link to post
Share on other sites
  • Replies 2.6k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

Popular Posts

That was a lot of wood to cut from the last four rings and my arms certainly know they have been used...but job is done...first 100Hz Upperbas horn front has been turned...      

Oh.  My. God.   It is freakin' huge.  I knew it was going to be big, but, well maybe not that big (apologies for the mess!)...          

My mate Dave wondered over and we lugged the front half of the UB horn upstairs.  Definitely a two man lift...almost a three.   Then we had to figure out a way to lift the 70kg+ back half on

That might explain why I have been preparing Cut Sheets in AutoCAD...making a circle cutting jig for the routers...profile jigs for lathes and grinders...sharpening cutting tools.

 

 

post-139669-0-32934800-1418975555_thumb.

  • Like 3
Link to post
Share on other sites

I am probably mad to consider building this behemoth...its weight will not be insignificant.  You can see the individual 32mm slices in green.

 

 

post-139669-0-05285300-1418976135_thumb.

  • Like 3
Link to post
Share on other sites


Below is my first draft of the assembled horns.  Depending on what I find when messing with crossovers and time alignment in particular, I would like to get rid of the frame and anchor the upper components to the big Upperbass horn and make it look pretty.  

 

Those that have an eye for horns will notice the similarities with a famous feline system.  This is not by mistake.  I figure I can mess with this stuff for a decade before I get it right or I can blatantly copy someone that has by all accounts got it very right and massage it to my preferences and save about 8 years out of that decade.  Fingers crossed!!

 

Then there will be the mid and lower bass to sort out...but that will be done when I move into the new room upstairs.

 

 

post-139669-0-06475900-1418976661_thumb.

  • Like 5
Link to post
Share on other sites

Will all be cut by hand John...a labour of love in front of the Boxing Day Test match.  If all works out as planned (ha...like that will happen!) I will show a cheap and groovy method of building these things that anyone can use without need of a gargantuan lathe.  The profile templates will be CNC cut but no-one I have contacted so far can do it before Christmas...so maybe I will be cutting them by hand also.

  • Like 2
Link to post
Share on other sites

come on Anthony, you can do it mate :)

Alan

 

You are at least partially to blame for this escapade Alan...helping me find all these vintage drivers from around the globe...the project might still be a daydream without your input mate.

Link to post
Share on other sites


I saw a need and yearning on your part, and you have the guts and desire to back yourself and work out all you dont have answers for right now. Those S2's and Fanes were details of the plan that emerged from the fog of the desire....You are firmly at the start line so good on you for that. Go well. It will all work out with a bit of persistence and seeking answers from those who have had the specific experience. Daydream might be....well....a bit premature? Lets call it a nightmare and then there wont be any disappointments or I told you's :) 

 

Keep us all posted. I would like a bit more details on those back chambers when you get to them-the volume bit. Cheers

Alan

Link to post
Share on other sites

Hi Anthony, I see you got your MDF from DMK. We could have supplied and Cnced it for you! ( Sorry shameless plug!)

However I gotta hand it to you, cutting circles in 32 mdf wouldn't be my choice, but it seems you have a computer design, so it will be easy for someone to follow your tracks the Easy way!

looking forward to your results. Ps, I have a mate who is developing a lathe for jobs this size and bigger

! Sorry help after the event is No help! 

Link to post
Share on other sites

If you don't mind me asking Anthony, how much did you pay for each slab of the 32mm MDF or was it cheaper for the pallet?

 

Thanks,

Brett

  • Like 1
Link to post
Share on other sites


If you don't mind me asking Anthony, how much did you pay for each slab of the 32mm MDF or was it cheaper for the pallet?

 

Thanks,

Brett

 

$88 per sheet delivered.  I got three quotes and DMK were the cheapest by a fair margin.  Didn't think I was going to save too much more on that price.  Good service from those guys.

  • Like 1
Link to post
Share on other sites

Hi Anthony, I see you got your MDF from DMK. We could have supplied and Cnced it for you! ( Sorry shameless plug!)

However I gotta hand it to you, cutting circles in 32 mdf wouldn't be my choice, but it seems you have a computer design, so it will be easy for someone to follow your tracks the Easy way!

looking forward to your results. Ps, I have a mate who is developing a lathe for jobs this size and bigger

! Sorry help after the event is No help! 

 

I got some CNC quotes and as you can imagine the prices varied substantially.  The cheapest price for CNC'ing once I took out the price of the MDF was about $500 (highest add $1k to that) but, and a big but, the cheap guys did not want to cut more than 25mm MDF and that would have meant about a quarter more glued joints which would make more work for me anyway.

 

So the plan is to use the circle jig for the initial cuts with one router and then use a simple follower in a second router to finish off the cuts.  Shouldn't take too long, and I don't mind a day or so of extra work if I can put that $500 into some other part of the speaker.  Every sheet of MDF has its own cut sheet already calculated so setting out the circles should be relatively straight forward and I should not have to think too much about it.  It took some wriggling in AutoCAD to get it all to fit on 12 sheets.

 

I thought of making a big lathe for turning the big horns (fairly straight forward to do) but my woodworking mate pointed out that the wood warps when it is spun and you don't necessarily end up with a perfectly round horn.  So we will use a slow spinning system that should be MUCH faster than a lathe and should give us a round horn.

 

@@Sparkle are you open next week?  Want to cut the profile templates from aluminium or ply? 

  • Like 1
Link to post
Share on other sites

mmmmmmmm 32mm  mdf drool. 

 

Was unloading it on Wednesday and the guy told me they do 44mm as well, but they aren't permitted to unload it by hand as we were doing it at the time.  Did some quick maths on the spot and I did not think I would be able to cut 44mm in the way I was planning so 32mm was still the right choice.

Link to post
Share on other sites

Awesome project, I remember the days of cutting countless circles of MDF for horns :)

Care to share driver details and what you are thinking for under 100 Hz?

Link to post
Share on other sites


Awesome project, I remember the days of cutting countless circles of MDF for horns :)

Care to share driver details and what you are thinking for under 100 Hz?

 

Drivers:

     Tweeter:       RAAL Ribbon

     Midrange:     Vitavox S2 (15R)

     Lower Mids:  Vitavox S2 (15R)

     Upperbass:   Fane Studio 8M (16R - original Fane production, not from the group buy - lucky me)

 

I will also play with an "Injection Channel" (ala Romy) using a vintage Goodmans fullrange driver (201c - 15R) as sort of a cohesive force to bring the big speaker system together.  Not sure how that one will turn out but it will be fun trying.

 

So as you can see, apart from the RAAL these are all hard to find drivers on similar impedance particularly suited for valve amplification.

 

Bass is the big question for me.  I would love to build a big bass horn but I just do not have the room so this limits me to direct radiators or tapped horns.  I would also like to have the flexibility to be able to physically time align the drivers and not rely on DSP to do that for me, so that rules out tapped horns and limits me to direct radiators.  Then I would like to run valve amplification for the 20Hz-100Hz region so I need to be really careful of back-EMF from the drivers, so smaller drivers with lighter cones and softer suspension are probably better here (in larger numbers).  So I have not made up my mind for the bass, but one thing is for sure, it will not be a half-arsed attempt because that large scale soft and realistic bass is just so vitally important in the context of the entire system.  I plan to first renovate the room, take some measurements and try to figure out the best solution from there. 

  • Like 1
Link to post
Share on other sites

Anthony, you are following feline fetishes (not unwise either), so why not go the multiple Scanspeak 25W/8565's. It would be very doable and compact. Chris told you what he thought of Romys bass.....

Alan

Edited by aertex
Link to post
Share on other sites

I am probably mad to consider building this behemoth...its weight will not be insignificant.  You can see the individual 32mm slices in green.

 

Seems we have a similar xmas project.    I'm using a completely different construction technique though  (EDIT - cos mine is a bass horn) .....    (Lathes and grinders are a bit beyond my capabilities).

 

 

Good luck!   :D

Edited by davewantsmoore
Link to post
Share on other sites

Anthony, you are following feline fetishes (not unwise either), so why not go the multiple Scanspeak 25W/8565's. It would be very doable and compact. Chris told you what he thought of Romys bass.....

Alan

 

Yes he did, and Chris is not the only one either that I have talked to that calls the feline bass as "best I've heard".  I have investigated just how cheaply I can get those drivers (or being Scanspeak just how much it would hurt!) and it is doable and it is my preferred option at this stage but I want to get some idea about room gain first.  Those bass line array's interact with both the ceiling and floor which is great if you have a flat ceiling, but my room has cathedral ceilings so they may well perform a little differently.

Link to post
Share on other sites

Seems we have a similar xmas project.   

 

 

But I have a thread going...hint hint Dave (again).

 

 

I'm using a completely different construction technique though  (EDIT - cos mine is a bass horn) .....    (Lathes and grinders are a bit beyond my capabilities).

 

 

Good luck!   :D

 

I would like to read about your Christmas project and look at pretty pictures too.  Especially to see what sort of design you have settled upon.

  • Like 1
Link to post
Share on other sites

Especially to see what sort of design you have settled upon.

 

Rectangular mouth hyperbolic of about 60hz (exact dimensions to be finalised) ....  made of plywood.

 

Driver fires down, so a 90 degree bend.

15" driver.   Fs = 35hz  Qes = 0.35

Lowpass filtered for LR8@250hz

  • Like 2
Link to post
Share on other sites

So, got my profile templates cut in 3mm acrylic today.  Have a look at the photo below to see how the inner and outer profile templates crudely fit together (blank spaces is MDF) for the three horn channels.  For scale I have placed a 30cm steel rule on the inner profile template of the Upperbass Horn.  

 

All excitedly I laid these out and explained to my darling wife what they meant and all she could say is "that's too big".  I smiled, gave her a kiss and retorted "that's too late".  Hehehe.

 

post-139669-0-80655800-1419299661_thumb.

  • Like 2
Link to post
Share on other sites

To give any that are interested how the outer profiles are calculated have a look at the graphic below.  You will notice that the curved shape of the profile template (the hatched area) is different to the desired shape of the outside of the horn.  This is because of how it will be cut, which you will see later.  The profile template is cut so that when I get the grinder with the wood-carving attachment running along the 3mm acrylic template that I don't have to keep it square to the centreline of the horn...I can twist and rotate the grinder and take off every bit of MDF it can reach and what will be left is the exact desired outer profile of the horn.  Simple!!

post-139669-0-26810700-1419299890_thumb.

  • Like 1
Link to post
Share on other sites

Have just ordered a Dayton calibrated microphone, Focusrite Scarlett 2i2 soundcard and the DATS (used to measure impedance, T/S parameters etc. for the old loudspeaker drivers I am using and LCR for capacitors, chokes, inductors, resistors etc.).  It's getting serious now!!

 

Will have to read up on software like REW, Holmimpulse, Arta and the like.

  • Like 1
Link to post
Share on other sites

I had better leave now...feeling all horny...

 

Will be watching with GREAT interest...

 

Come on cows...eat more of that new green grass...

Link to post
Share on other sites

Made the first wood dust today, hooray! Did not get as much done as anticipated but messed around in the morning welding some reinforcement to take some wobble out of the lathe and then cut a couple of sheets of MDF finally settling on a protocol to do the cuts: use the circle jig to cut about a centimetre deep with a 6mm bit then finish the cut with the jigsaw. The circle jig is screwed to the centre of each circle and the router dragged around anti-clockwise. In hindsight the circle jig should have been made to take the big router (not the small router) which would have make the initial cut quicker, but we were going to use the big router to finish the remaining 25mm of cut which has now been tasked to the jigsaw.

Today the outer rings for the Upperbass Horns were cut and...wow...they are big...and beautiful in their own way. By tomorrow evening one midrange horn should be ready for undercoat, if not both of them depending on how long it takes to fabricate a bracket on the lathe to accept the profile templates for cutting the outside design shape of the horns.

No photos today, maybe some tomorrow.

  • Like 1
Link to post
Share on other sites

$88 per sheet delivered.  I got three quotes and DMK were the cheapest by a fair margin.  Didn't think I was going to save too much more on that price.  Good service from those guys.

 

DMK stands for? I need about 6 sheets of 32mm MDF delivered once I get my CNC finished in the new year.

Link to post
Share on other sites

This is a huge project ... so much wood work involved ...

 

How tall will they stand once finished?

Somewhere about 2m is pretty right. If I experiment with an Injection Channel then over 2m tall for sure.

Link to post
Share on other sites

Did not get much done today...lost most of the day to friends. Here are a couple of photos of a midrange horn ready to go on the lathe.

post-139669-0-41304100-1419756004_thumb.post-139669-0-35074600-1419756072_thumb.

EDIT: correct photos this time

Edited by acg
  • Like 3
Link to post
Share on other sites

Have been very much sidetracked by the festive season and my best intentions of knocking out some big days on this project were effectively scuttled by the lovely distraction of friends, an early departure for a beach holiday and the corresponding belated return.  Will spend tomorrow morning finishing all the cutting for the six horns and then see where I can find time to further modify the lathe so I can turn them all into shape.

 

Learnt a good lesson today...had been borrowing a friends jigsaw for the cutting (circa $100 Makita) but this afternoon had to buy my own.  I got a $120 Bosch and OMG this thing absolutely flies...I had been taking about two hours to cut out a full sheet of rings with the Makita but the Bosch does the same thing in about half an hour...tools certainly ain't tools!

  • Like 1
Link to post
Share on other sites
  • Recently Browsing   0 members

    No registered users viewing this page.

  • Similar Content

    • By sir sanders zingmore
      Item Condition: minor cosmetic damage Shipping Options: Pickup available and you can audition. Suburb or Town: Glen Iris State: VIC Payment Method: Paypal (as a friend), EFT, Cash on Pickup Reason for selling: NLR Further information:
      A rare opportunity to own these legendary horns. 
       
      Note there is a scratch on the back of one of the horns. The photo makes it look much worse than it actually is. Also, it's on the back, so you'll never see it.
       
      There is a set on audio shark in Germany for EUR 12k, so I think my pricing is good. Especially as these look so much nicer!
       
      Note: I do not have boxes for these so local pickup is preferred

      Photos:
       

       

       

    • By mwhouston
      To get a grasp of where I’m am going with this thread you need to of read or have read  this article. 
       
      https://www.stereophile.com/content/gramophone-dreams-34-salt-cellar-system
       
      If you go no further at the least it is in interesting read. Some will go “meh” others will take it on board to search for better reproduction. Maybe even build there own SC. The challenge I have given myself and would like to throwout to others is can you build or hobble together a “Salt Cellar“ (SC) system. The core of a SC system is purity of sound, dynamics and immediacy. 
       
      These are the constrains/opportunities I’m am pursuing;
       
      a monaural system high efficiency speakers - horns where possible a tube low power Class A mono power amp or even tube integrated amp vintage tubes mono vinyl phono playback from mono cart or mono wired phono stage  ultra short non shielded interconnects and speaker leads of Silver plated wire wrap wire ?

      Ive been tossing this temp system around since I read that article and now have  (in my head) a whole SC system. So cutting to the chase I’m going to build a mono integrated wine box tube amp based on some vintage 807 and RCA 6SN7. Half the 6SN7 will be a single stage preamp and the other half the driver for a Suncalc designed 807 amp.
       
      Speakers will be my Beyma 12” concentrics with a Altec 511B horn and FatalPro driver. The horns will handle mid-range and the tweeter in the horns super tweeters. Overall efficiency about 98db. 
       
      Im current working three other projects but now taken on a forth for a true SC system. Any other takers out there. 
    • By gypr1961
      Item: Avantgarde Zero 1 XD Active Speakers DSP
      Location: Brisbane
      Price: $17,500 ONO
      Item Condition: Mint
      Reason for selling: Time for a change
      Payment Method: Pickup - Cash, Paypal, COD Only
      Extra Info:

      These are the top of the line model, above the pro model and come with DSP, digital and an analogue (A/D card) for turntables etc.
       
      They are incredibly dynamic! They sound just as good when theyre shaking the house or playing whisper quiet. 
       
      I have all original packing so transport is not an issue
       
      As im going to need a complete new system Im happy to look at trades
       
       
      Specs can be found here https://www.avantgarde-acoustic.de/en/products/zero-serie/zero-1-xd.html
       



    • By leqt1969
      Item: Avantgarde Acoustic UNO speakers
      Location: Bexley NSW
      Price: $8,500 ONO.
      Item Condition: Used but in great condition, superb sonically.
      Reason for selling: Going different direction
      Payment Method: Pickup - Cash
      Extra Info: Advertise on behalf of a friend in Bexley NSW who doesn’t have SNA account.
      Grab your chance.
      Avantgarde speakers are rarely seen on second hand market. These speakers are in great condition and sound superb. Still have original box but pick up preferred due to weight.
      Audition can be arranged for serious buyers.
       
       
      Photos: Advertisements without photos of the actual item will not be approved.



    • By La scala
      Item: Klipsch La Scala speakers 
      Location: Perth metro
      Price:  $3500
      Item Condition: Great for their age, 1978 ish Alnico 
      Reason for selling: Told to shed some gear
      Payment Method: Pickup - Cash,  Bank Tranfer COD Only
      Extra Info: East coast buyers, can do live video demo via FaceTime 
      These have the favoured Alnico Magnets, serviced X Overs and updated Mundorf Capacitors, some body bracing to tighten bottom end.
      All drivers work spot on.
      Sound wise, these have a uncanny ability to project a very large wall of sound with fine detail and dynamic authority.  Impressive as I am normally into Electrostats, Planar and Ribbon speakers. Very versatile and allow use of Set Valve Amps due to their 100db efficiency. 
       
      Photos: Advertisements without photos of the actual item will not be approved.







×
×
  • Create New...