S15: Econowave DSP - a Constant Directivity vs Dipole study

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Thanks for the reply Gain!

Well, me being 41 yrs old, and never ever needing the emergency room for nothing until this hit me like a ton of bricks, but I've been recovering from surgery for the last 3 weeks, I'm off weight restrictions, and finally getting around to building some Econowaves !!!

I was looking to either build zilch's Econowave deluxe version, but when I saw your set that you made, I was very impressed that maybe your set would be a better fit for my room, as I want to build a right, left, center version for my home theater, but I wanted to just buy the cross-overs or buy something through you, I'm not sure with Zilch's design ( if his design uses 12 or 15" woofers ), but some of the Econowave designs were made with 15" woofers, where I wanted to stick with the 12" designs, that would work with my other speakers.

I will check out the thread you linked in your reply, again I really appreciate your help! Thanks again!
 
econowave.jpg


James Murphy from LCD Soundsystem appears to be mastering his music with Econowaves now!

Neat.

In the pic above, I've pasted an Econowave on the left, and James Murphy spinning on the right. (Note the econowaves behind him.)

On the downside, he mentioned in the video that he 'makes studio monitors for DFA' (his label) and that 'artists on our label can make a beautiful pair of studio monitors for $700.' But he didn't bother to mention it's origins :( (Sure looks like an Econowave to me.)

Hopefully he gives credit where credit is due.

Full video:

Despacio soundsystem: James Murphy and 2ManyDJs in conversation - YouTube
 
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hello gainphile. i have some questions regarding the crossover in these, that seems way off to me.
i can see both the 20hz and 35hz linkwintz transform has a massive +20db boost all the way to 10hz (!) for some reason, why is this?
An externally hosted image should be here but it was not working when we last tested it.


example one, a passive speaker pretty close in principle to the active, makes it to around 37hz -3db without any electrical EQ.
Fusion-12 Tempest DIY Sound Group

example two, although the LXmini has much lower effeciency it doesnt utilize linkwitz transform and basically can do with a 7db 50hz peak, making it 45hz -3db. no boost at lower frequencies as described in the design section:
"Equalization is achieved by a 7 dB peak in the frequency response of the DSP. This form of equalization is advantageous because the response drops below 50 Hz towards 0 dB, thus relieving the driver somewhat of excessive excursions below the peak frequency."
An externally hosted image should be here but it was not working when we last tested it.



i find the 20hz config unusable with moust of my equipment because it easely clips the output of the minidsp. a 20db boost would imply lowering the input voltage by the same amount to prevent it from distorting. swapping the jumper from 0.9V to 2V doesnt do much either, because its only a resistor, padding the signal down by 7db. the IC would clip when input/ouput relations are the same.
when lowering input voltage enough to prevent clipping, you would have a new problem, not enough voltage into the amplifier.

why is this massive boost even there? it strains both the crossover and the woofer excursion for no reason, if the speaker is measured to 35hz -3db all the EQ at lower freq has no porpuse but to increase distortion.
i find it quite odd..

thanks
 
correction, ofcourse i relize that the speaker would dig significantly deeper. adding a bit of bass in an active setup is fine, but using your front speakers with a single 12" 3mm woofer as as a partial subwoofer is a different matter.
i tried editing the parametric EQ band 2, but the settings get reset when switching to basic, so i wouldnt know what the settings are.
if i bypass EQ band 3 it looks better, but it also effects freq response from 100-200hz.

An externally hosted image should be here but it was not working when we last tested it.


i wonder, since a passive version has the potential to be quite flat, and linkwitz manages with one simple boost, why add this amount of EQ and increase distortion when it still "only" does 35hz -3db?
thanks.
 
So many questions I will try to answer to my best :)

hello gainphile. i have some questions regarding the crossover in these, that seems way off to me.
i can see both the 20hz and 35hz linkwintz transform has a massive +20db boost all the way to 10hz (!) for some reason, why is this?

Yes those settings are to reach the very bottom and demands a lot of excursion. Threre is not a lot of true 20hz, Q=0.5 loudspeakers out there!

I'm surprised that it clips on your system as in mine they play really loud (4mx7m room) with no issue and use cheap ebay amps too. I prefer the 35hz one btw. There's an old clip here: https://www.youtube.com/watch?v=SwSK8dmeqgU

I guess you can change the LT to 80hz and use subwoofers if high SPL is needed? It will only need +6dB at 20hz.

biquad1,
b0=0.995473274214229,
b1=-1.97915051273455,
b2=0.98381459056817,
a1=1.97916492622105,
a2=-0.979273451295896


example one, a passive speaker pretty close in principle to the active, makes it to around 37hz -3db without any electrical EQ.
Fusion-12 Tempest DIY Sound Group

They are ported/bass reflex loudspeakers, not sealed. The lower octaves are emmitted by those holes and there are a lot of debate whether this is fit for audiophile use. Loud, for sure :)

example two, although the LXmini has much lower effeciency it doesnt utilize linkwitz transform and basically can do with a 7db 50hz peak, making it 45hz -3db. no boost at lower frequencies as described in the design section:

They are 5" drivers, and I can tell you the excursion will be crazy if one tries to equalise to 20hz. I did this with my pluto clone. EVERY ONE who had listened to them had to walk and see for themselves. Quite impressive.


why is this massive boost even there? it strains both the crossover and the woofer excursion for no reason, if the speaker is measured to 35hz -3db all the EQ at lower freq has no porpuse but to increase distortion.
i find it quite odd..
thanks

There will always be compromises between SPL and frequency extension. Try to equalise it to 80hz as above ?

i tried editing the parametric EQ band 2, but the settings get reset when switching to basic, so i wouldnt know what the settings are.
if i bypass EQ band 3 it looks better, but it also effects freq response from 100-200hz.

EQ3 is for baffle step compensation. It is needed if the speakers are breathing free (e.g. 1m from front walls), but not needed when they are against the wall.
 
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I am very interested in building these speakers, but i cant find any measurements ??
On the other hand measurement do not mean a lot =D...

so my easy question ? I won't regret building these speakers for a 20m2 room ?
Do i need a subwoofer ? Are they good for old rock ike ? jimi Hendrix, eric clapton,... ?

greetings from germany =)
 
Hi I am thinking of building this design.. Or simuler.

1) can i get a decent responce with passice components?

2) surely using a dsp to make a 12" pa driver play 'flat' to 20hz causes v high cone excursion and limits headroom.
Just a sence but I feal 45hz or so to be about right.
I would like to go with a roll off at about 60 smoothing down to 50 -3db or as feel a good sub can be built for lower tones
 
I am very interested in building these speakers, but i cant find any measurements ??
On the other hand measurement do not mean a lot =D...

so my easy question ? I won't regret building these speakers for a 20m2 room ?
Do i need a subwoofer ? Are they good for old rock ike ? jimi Hendrix, eric clapton,... ?

greetings from germany =)

Greetings! There are some measurement if you click on the links ie. tweeter, woofer etc. Regret .... I've had no regrets building my own speakers yet except the continuing pile of drivers ;). Should be good for rock and no need for subs unless you listen like in discotheque!


to gainphile:
What realy internal volume of box?
What will with sound if I leave this volume, but change the box size?
I want to make a width of about 41-46 and reduce the depth to 25-30cm.
Is itt Possible?

Hmm I don't know I suppose just multiply WxLxH in the diagram but take account of 18mm wood width? All it affects is the Linkwitz Transform calculations and some (if significant) the baffle step frequency.


Hi I am thinking of building this design.. Or simuler.

1) can i get a decent responce with passice components?

2) surely using a dsp to make a 12" pa driver play 'flat' to 20hz causes v high cone excursion and limits headroom.
Just a sence but I feal 45hz or so to be about right.
I would like to go with a roll off at about 60 smoothing down to 50 -3db or as feel a good sub can be built for lower tones

1. It will be hard. Have a read at 2PI's (Wayne's) whitepaper.

2. Yes, it is always a tradeoff between SPL and Low Frequency. I run them to 30hz and happy with both the SPL (wife yells) and LF.


By all mean don't try to copy. Just build something and share :p

p.s. I saw Klipch had an 'econowave' design on an audio show yesterday. They sound good and looks simple! I like them! Maybe copy it :D

70th-Anniversary-Heresy-Angled-Grille-3.jpg
 
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