My next project open baffle 4way (15" 12" 10" econo waveguide) help

[charlie2]

Hi can i have some advice please I have read lots of different topics on this (OB)

But looking for the critic type of response.

Each baffle size will be 55" high 16.5" wide ex dining table

parts on hand are

Eminince alpha 15a x2 currently in H frame (mjk)

jbl 2206h x2 salvaged from this thread http://www.diyaudio.com/forums/multi...rgain-not.html

celestion tf1020 x2 bought cheap £20/$30 each from maplin uk new ( have 4)

jbl 2426j compression driver x2 salvaged from the above thread

econowave jbl copy pyle ph612 waveguide x2

xover point recomendations needed please, and driver ctc spacing (off set reduce height or straight vertical)

need good loud unstrained sound if possible not beaming straining hence the choice of drivers coupled with the benefits of open baffle

miniDSP 2 - (2x4)

2x qsc rmx 1450 bass--bas/mid
1x yamaha p2500s mid
1 yamaha reciever for tweeters also pre for all amps

thoughts please

[charlie2]

I have just done a quick sketch drawing of possible arrangements could you please advise on the pros and cons of each one, itching to get the jigsaw going.

This will be my last build for a while due to house renovations and time constraints so would like to get this of the ground soon thanks

basicly A off set drivers reduce spacing verticly

B align drivers verticly

C align drivers verticly with tweeter inbetween 12" and 10" probably around ear level

and the pitfalls to each one?

[evanc]

Home of the Edge
check it out...

[picowallspeaker]

Too many big membranes around: one thing is a big 15" producing waves in both senses, another thing is a 15 +12+10 ".
Too many motors !

The way you should move would be : I've got this 15" (hmmm..some say the Beta is better ) but when mounted &crossed& equalized I feel the need for a tight mid-bass which isn't coming out from the -say- 5" midrange , so sorting out from the drivers I have I might put in use this 8...or 10 ".

with the benefits of open baffle

If you know how to get them useful, otherwise it's just a bunch of drivers slapped onto a surface

[LineSource]

Why did you rule out:
--Sealed box with 12" JBL 2206H, (sealed for low phase shift and fast transient low Qtc)
--plus Pyle ph612 waveguide with JBL 2426j compression driver, (90H x 40V good for HT)
--on top of dipole Eminence alpha 15a? (DSP equalized)

A dipole woofer has a directivity index(figure 8 polar) which removes some room interaction.

You could watch for deals on "husky" 15" - 18" woofers with favorable sealed T/S parameters for future experiments.

[evanc]

You have the drivers and the baffles ....try it.....you might like it. The tweeter set high so you are a bit off axis when seated might not be bad. You will need a 2x8 mini dsp or similar.

[charlie2]

Originally Posted by LineSource

Why did you rule out:
--Sealed box with 12" JBL 2206H, (sealed for low phase shift and fast transient low Qtc)
--plus Pyle ph612 waveguide with JBL 2426j compression driver, (90H x 40V good for HT)
--on top of dipole Eminence alpha 15a? (DSP equalized)

A dipole woofer has a directivity index(figure 8 polar) which removes some room interaction.

You could watch for deals on "husky" 15" - 18" woofers with favorable sealed T/S parameters for future experiments.

If I did this i think it would be an Econowave on a H frame, and possibly have time allignment issues, i have not realy seen this set up around the net r.e. sealed box on top of H frame

My first open baffle was a pleasure maybe not perfect but the sound of floating notes hanging in mid air was special, needs to be heard.

I then built the existing baffle into H frame with mid baffle the sound was never the same so I chopped off the baffle leaving just the H frame.

I then cut a baffle flush mounted the celestion tf1020 and placed it at the front of the H frame with a cheap small full ranger for tweeter duties this brought the majic back of non box resonance sound , but time allignment issues arouse and you still get it with Hframe (resonence)

then the JBL,S came along so next project is born.

ps I got a good deal on husky 18" autotune it can sing now the exhaust has been modded

[InOtIn]

I think this has potential


Have you tried that setup but with the 2206H instead of the TF1020? Or as-is with the 2426J/PH612 on top instead of the small FR tweeter?

[Juhazi]

A corner loaded ob??? Those things need more air around or you are in trouble with cancellations/doubling peaks.

[charlie2]

Originally Posted by InOtIn

I think this has potential


Have you tried that setup but with the 2206H instead of the TF1020? Or as-is with the 2426J/PH612 on top instead of the small FR tweeter?

I have not progressed to any further testing in regards to having the baffle to the front of the H frame after reading this. (9"offset)



Correcting acoustic center offsets in dipole speakers...
http://www.google.co.uk/url?sa=t&rct...31fQwTYN7yB3bw