Big Speaker Project, 18” + 10” + CD/horn, super tweeter

Rebuilding my Ekta Grande’s and ScanSpeak subwoofers didn’t satisfy my need to build something.

I’m really excited about the overall improvements in sound from the changes, and this build does not indicate unhappiness, but I really want to build a BIG speaker, just to say I did, if for no other reason.

Within reason, I’m not planning on cutting any expenses or time. I have ordered most of the crossover parts from Jantzen and the drivers (except for the super tweeters) from Lean in the UK. Drivers track delivery next Wednesday, no tracking yet from Jantzen.

B2C8093B-F56B-4923-8868-6B8FEC1C6228.jpeg

Big drivers take a big cabinet. 42” x 26” x 18” (H x W x D), all 1” material, double milled Medex for the painted parts, Maple veneer/Baltic Birch for the others. Maple hardwood frame, plenty of bracing.

After the fun and success of the new Hypex Fusion FA501 plate amp for my subs I’ll be using the FA502’s here. One channel for the MTT and the other for the 18”. There will be 4 sets of binding posts so I can use jumpers to choose full Active, partial Active, bi-amp from outside source, single outside amp. Versatile.

Been scribbling notes all day to give to my CNC friend to input and cut stuff up. All good fun.

Cabinet design will be somewhat simple, going for elegant, understated, and not a copy of anything I’ve seen before. For sure nothing that looks like a transformer that may come alive and come get me in the night!

I made an outline/template and have had laying on the floor for a couple days to get a feel for the size. My wife told me to go for it, so one hurdle out of the way!
 
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Hi Coast to coast.


What crossover frequencies are you thinking of using ?


What is the upper usable limit of the 10" ...

... & the lower usable limit of the compression driver in particular.


Are the drivers a close dB/Watt match for each other ?

Have you got the dB/Watt @ 1 Meter specs. for the 4 drivers ?


Integrating the power levels of the 4 different drivers ...

... & finding the best X-over point between the 10" & C.D. is a brain teaser.


Si.

t.S.E.c

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TOPIC: Edge diffraction effects on large front baffles:
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Earl Geddes measurements show value to cutting large radius quarter rounds on all baffle edges. Review his SUMMA speaker literature.
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" Originally Posted by Patrick Bateman ---
A couple of things have been vexxing me lately:
1) If you put a *significant* roundover on a cabinet, the polars get measurably better. Here's an 18Sound XT1086 with and without a roundover. In particular, notice the improvement in the midrange. "

The Preference for Direct Radiators

Watch this thread for additional measurements and discussion.
 
What crossover frequencies are you thinking of using ? <snip>

Thanks for posting!

Just getting started, but I have a plan.

One question I can answer is that the points of crossover are 200, 1300 and 9000 Hz.

TOPIC: Edge diffraction effects on large front baffles:

Thanks, and yes, my cabinet design has some allowance for edge diffraction. May or may not be the ultimate but the vertical face of both sides of the baffle will have a 2 1/2” diameter roundover. At least at this stage of the design.
 
" One question I can answer is that the points of crossover are 200, 1300 and 9000 Hz "


Hi Coast To Coast. :D


I haven't studied the driver specs. or anything ... :eek:

... but can you say why ? you chose those frequencies ?


My intuitive feeling would be to try and get ...

the 200 lower

the 1300 higher

& the 9000 higher


Mmm ... :eek:


I'm an amateur, who doesn't like scarring bats ... :rolleyes:

... hates subwoofers ... :mad:

... & loves 3 KHz crossover points though ! ;)


Si. :)

t.S.E.c

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Hi Coast to coast.
This system you is going to build looks like a copy of this speaker from Troels.G

The-Loudspeaker

why not buy the original crossover ..it is not cheap but make the speaker play like a whole ...and it sound very well

Best Bjarne

+1. I was gonna post that same link.

The speaker you're looking at making is very similar to what's already been done. Take hints from someone that's done a lot of hard work for you!

Chris
 
I wanted to build JBL 43xx clones for a long time. When the realization that original drivers were getting scarce and expensive, alternatives became realistic choices.

Two things occurred to me. One was that the designer of those big speakers had moved on, and his personal stereo used totally different arrangements. The second was that an individual who had some big 43xx had opined that now a similar performing speaker could be pulled off in a 3 way using the SEOS waveguide. Surely a few things have changed over time that allow us to do things a little differently than the old way.

When I found Troels The Loudspeaker, I got excited. Here was a speaker using modern drivers and designed using modern tools and parts, surely it has to be an improvement on the old design, no? I was a bit shocked to see he went 4 way, but Troels' forte is crossover design, so of course he won't make any compromises.

Since you've essentially ordered the drivers he used, I would take it in that direction. I feel like crossover design is the sword I will fall on when it comes time for me to build my speaker. Having that figured out would allow you to focus on the finish work, and there is no shame in not designing your crossover if your speaker sounds great in the end and looks the part. If those drivers were in my budget, I'd be all over The Loudspeaker.

Not only that, but there are already members who have built them here. Having them and possibly Troels able to advise would be nothing short of awesome, and something some of us wish we had when taking on our own projects.

Regardless of how you take this, I think it's awesome you're doing it, and look forward to your progress.
 
Thanks all for your comments and recommendations!

I left a trail of breadcrumbs in my postings, my Ekta’s are a Troels design, drivers match “The Loudspeaker”, all Troels designs use crossover components from Jantzen, which I posted I had ordered from, cabinet size is mm to inch converted similar, and the crossover points posted exactly match “The Loudspeaker”

Cabinet construction will be starting next week, but will take a bit of time with holidays, travel, ets
 
It will be a great speaker you will get .... coast to coast---

i have some picture ,,,but it will be the same as on Troels G homepage

i will hope before Christmas i will post on Troels page...tell a little about the sound ,,and show a picture i have not learn to post picture hear on diy audio...

about the sound...it is in many way the best speaker i have build...specially i like the voices ,,sound lifelike you can easily hear the word,,with all the dynamic ,,acoustic guitar sound so clear ,,i have not heard this with ordinary dome tweeter.. and the sound from the 18" bass...it plays so easy and controlled ,,and with big sound. and -- they can play loud ..without any problem... i hear the most Music dvd...and there the speaker really shine...

eks,,a dvd with Godsmack -where the play live acoustic----it sound so live and clear.newer heard it better...i feel i am to concert..

Darwin---Troels use only Hypex for the 18"...he use Tube amp for the top--so the supertweeter make sence...give the last top om the sound from 9khz

i use my Gryphon Encore amp for the hole speaker...so i have 500w to play with

Best bjarne
 
I must say that "the loudspeaker" makes for an interesting read but given the choices of drivers and the available knowledge today that approach is not practical at all. For one thing there is no need for an 85kg+ box when the bass unit can be made separate and the MH unit can be stacked up on top.

Moreover if a biamped approach is taken a smaller driver can be used for bass duty. I have 12inch 2,000W rms rated drivers in backloaded horn bass bins (design off Beyma website) which can be used on a live stage let alone at home at some 0.x% utilization. I also have 15 inchers on a 25inch wide OB which hardly move when playing string bass at live levels.

btw I also have in boxes the 18sound horns which Troels used, but if I do anything with those and CDs some day it will be for PA duty.

the only useful reference I find in this project is another confirmation that midbass is best performed by an 8-10 inch driver. However, as soon as he decided to introduce that driver calling for padding CD and a boxed 18incher to end up at 95dB sensitivity kind of killed the concept.

To sum it up, the point is not to make "a big" speaker but to make a speaker just big enough "to sound big" in a given space (without causing booming of the room resonances).

p.s. you may also consider refraining from the practice of "leaving breadcrumbs" and acknowledge the speaker designer from a get go.

Have fun building. I hope you will be happy with the result.
 
koja
it is right one can make a speaker of different size and shape...but from my point it is hard to get the speaker sound as one unit..crossover is very important...different size,,different crossover...but of coarse it is not impossible to make new crossover..

the Loudspeaker does not sound like PA speaker..

best bjarne
 
Darwin---Troels use only Hypex for the 18"...he use Tube amp for the top--so the supertweeter make sence...give the last top om the sound from 9khz

Best bjarne

Yeah but the OP is going to use 502s.
The 18Sound compression driver easily does 20kHz with the right horn-appropriate eq so I can't see the supertweeter adding much beyond another source of comb filtering.
The bottom end of that particular driver appears more of a problem since it is only recommended above 1.6k rather than the intended 1.3k but with a steep filter that shouldn't be much of a problem if used domestically.
 
Did you also consider using 3-way DSP with 1-amp per speaker, plus a passive Xover on the super tweeter? There are a bunch of parts in series to the magic midrange which go away. It has become popular to have one 3-4 way ( DSP + amps) and just move it around to multiple speaker boxes.

Bryston is one amp company looking forward with their Active Speakers. Cabinets with only drivers in the box, connected to a Bryston multichannel amp with DSP.

"A plate amp is forever."
 
that horn should be used from 1.6kHz and up to get the constant directivity it was intended for.

If I was to just build something big then a modded Visaton monitor with some constant directivity design measures like this would have been a choice:
YouTube

However, I am pretty sure that after listening to my OBs everyone would say that the difference in sound did not justify the difference in size and weight (at least not in my listening space).

People should carefully read Troels's posts to distinguish when he is really sharing some personal insight (like on his page on high sensitivity speakers and OB), as opposed to just experimenting for the sake of using 18sound and Jantzen parts, (he already had the relationship with the latter and now apparently was introduced to the former as well, thus "the loudspeaker" project).
 
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Hi Koja.


To post photos here ...

... click on Post Reply under the last Posters message ...

... then when you get to the 'main' reply window ...

... under that is another button called 'Manage Attachments' ...

... click on that & 'Browse' your computer buttons come up, where you can choose & upload your pix.

When pix are chosen, hit the upload button & pix will be visible as attachment links under the Post Reply window.

Then just hit the Post button to send your message & photos.


Hope that helps.


Si.

t.S.E.c


The super-tweeter does seem to X-over way too low & is a bit superfluous really ...

... probably better to keep that 'delicate' 9K area free of smeary filtering.

Oh well, more is always better, right ?

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