Mannsize. 3.5way active cardioid´ish

manninen

Member
2014-07-16 7:49 pm
Mannsize. 3.5way active cardioid´ish project

Gear from old steel is real thread has time to go for 2020.

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New idea is to use jbl 3730 mid/high waveguides and 4x12" on front and one 12" on the rear of the box, 4channels active.

height is gonna be 160-180cm
 
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manninen

Member
2014-07-16 7:49 pm
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Being rounding up if waveguides were passive, that releases some channels for bass management.

Today tried end fire system, kind of. delayed front played fullrange and 1m back played to 100hz. 1ms gaps multiple measurements and listening what it does.

if i hook speakers front and back it might be only 30cm between voicecoils.

yeah i have to think about it all
 

manninen

Member
2014-07-16 7:49 pm
I have bitum on midhorns back, i might use stp black gold on high guide. High guide is not yet on that simulation. i´ll bet those polars is PIA to measure indoors, can´t go outdoors cause it´s freezing outside. speakers this size what is even correct way to measure?
 
I once made an indoor test with cardioid bass system. Two boxed woofers back to back and minidsp variable delay. By theory this kind of system has only narrow band for cardioid response, because of physical separation of sources.

Indoor measurements didn't give me much reasonable. So, go outdoors! Bass close to front wall or in-wall is very good but room modes are always there!
 

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Zvu

Member
2009-01-15 6:52 pm
Belgrade
It all depends on level of precision that you want to achieve. Of course measurements can be done indoors too. It takes a little (or a lot) longer to get things right but it's not impossible.

Outdoor measuring is not expensive, it's just a bit complicated becuse it demands that everything is battery powered. Other than that i keep geting the cleanest and most resolving results outdoors. With anechoic chambers there are always problems with lower end of the spectrum. They are great for distortion measurements and all other types of measurements where the climate is/can be harsh.
 

manninen

Member
2014-07-16 7:49 pm
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simulated polars from just 4x12" on front. those jbl waveguides should give me DI >9 from 400hz, its quite good match but my audio friend noticed directivity rise up quickly from 100 to 500hz

what we could do is on both side to the box another 12", 6x12" on one box two active channels.

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we can bend directivity on needed area, area aint big and not wide but there is things happening.

Thanks ville for helping me with vituixcad

that diamond shape 5674 woofer arroy i cannot do, height goes over 180cm with that one
 
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manninen

Member
2014-07-16 7:49 pm
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More simulations done, that quad 12" would give nice punch but seems that 400hz is too much for that setup directivity wise.

So i lowered my output capacity to 12" on rear and 12" on back.

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rear driver gives me this, i hope it kills front wall reflection

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driver height looked well after jbl factory, midrange height is just above floor reflection and woofer can be placed under that reflection.

Does anyone know high playing 18" which could do well 400hz

I only know phl audio which genelec use their largest monitor.
 

manninen

Member
2014-07-16 7:49 pm
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this is issue with 4x12" on front.
upper woofers needs to be 190mm back them to match lower woofers, its just about limits to reference axle.
picture of all being on and just 2row uppers with same eq, lower woofers slightlty cancelling output allready

i have two sealed speakers, today i listened them to be endfired.
does not do much against the wall, but what it do it kind of accurate 70hz area but everything around kind of level up.

might be that these type of speakers need more space to work better
 
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manninen

Member
2014-07-16 7:49 pm
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Bass boxes are playing!! F1 on top cause jbl high horns are delayed.
Cardioid setup made 100% vituixcad diffraction tool, i believe quite true under 100hz.
Bass is definitely most different i´ve had in this room.

12" on baffle aint that good as inlow 135hz horn was.