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

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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:no: :smash:

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/mult...ers-butcheeks-2344a-modified-bargain-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
 
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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

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


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?
 
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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
 
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.
 
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)

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


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
 
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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=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0CCAQFjAAahUKEwjzkrvX1ZLIAhWEez4KHX1VB9c&url=http%3A%2F%2Fwww.musicanddesign.com%2FDipole-offset.html&usg=AFQjCNHk6Ebb4v8UGoUS31fQwTYN7yB3bw
 
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Me too.

I'd cut out the 12" driver. There really is no need, when you've a 15" for bass and a 10 that'll meet the tweeter nicely. What I'd be looking into is dipole tweeters. I recently tried something similar to what you're looking at, and found the monopole source 1kHz and up messed up spatial cues from the <1kHz dipole below. I'd try to keep it all one way or the other.

Will you be using passive crossovers or active?
Do you have any EQ capabilities?

Chris
 
:rolleyes: You lost me at 4 way

WHY??

Is linkwitz lx521 not a 5 way?????

each driver handing down to the next?

were you lost at full range or at 2 way open baffle

I am sat here currently with a madonna track on constant A-B repeat trying to get the best from a Eminence alpha 15A .

Wether it be be dipole, ripole, h frame etc, or the best i can make from it in its limited in application seems to be 100hz crossover without FARTING
 
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Me too.

I'd cut out the 12" driver. There really is no need, when you've a 15" for bass and a 10 that'll meet the tweeter nicely. What I'd be looking into is dipole tweeters. I recently tried something similar to what you're looking at, and found the monopole source 1kHz and up messed up spatial cues from the <1kHz dipole below. I'd try to keep it all one way or the other.

Will you be using passive crossovers or active?
Do you have any EQ capabilities?

Chris

sorry Chris but thanks for your limited input you have no idea and have been reading too much gobbledygook

If you had read the original post you would see that DSP is on hand as well as plenty of amplification.


how can you recomend cutting out any size driver or its parameters without experience of them and when no crossover points have been mentioned?
 
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WHY??

Is linkwitz lx521 not a 5 way?????

No, its a 4-way system with the two bass drivers covering the same range.


sorry Chris but thanks for your limited input you have no idea and have been reading too much gobbledygook

If you had read the original post you would see that DSP is on hand as well as plenty of amplification.

how can you recomend cutting out any size driver or its parameters without experience of them and when no crossover points have been mentioned?


Fine, if you say so. Where would you suggest I do some reading? - so far I've mostly been reading the things on this forum, with quite a lot of focus on human hearing, acoustics and speaker directivity.
Aside from that, all I did was report my findings. Having a lot of reflected energy below 1kHz and not-much above gave a very odd sound. I suspect that's why a lot of OB systems either use supertweeters (>10kHz, where our hearing isn't too sensitive) above a wideband mid, or rear-firing tweeters if the HF unit is covering a sizable range.


Okay, what're your proposed crossover frequencies?
I honestly think that using two drivers with a crossover to cover the range that one driver could do very easily is just bonkers. The 10" won't be short on headroom around 100Hz, and will easily meet a tweeter. Taking it up to 400Hz won't make any difference there IMO.

Chris
 
Linkwitz 5way or 4 way was not aimed at you (I suggest you do re read the posts previuos) theres a start;) ie read the original post.

secondly (your suspicion of alot of open baffle speakers using super tweeters) is flawed if correct it would turn them into 3 ways at the bare minimum:rolleyes:

the with the compression driver I have and waveguides it still will only take it into the 16k region without boost if it can take it?? so maybe with a super tweeter that takes it to a 5 way:eek:
 
Ohhh, I'm terribly sorry, I didn't realise I wasn't meant to contribute to an open forum.

I'll leave you to it.

Chris you were not the one to state that you were lost by (4way),, THIS WAS AT POST#11 and its contributer

But for some reason you are compelled to think that you were attributed to it:rolleyes:

But by also reading the opening topic, and the contributing posts you should have simply realised this.



~~~~~~~~~~~~~~~~~~~chris661~~~~~~~~~~~~~~~~ decided to delete his previous post
 
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Yep, I deleted my post after deciding it was a bit snappy.
I agreed with Bare, that a 4-way design doesn't seem sensible here.

As it is, though, I don't think I'll contribute much, so I'll leave you to it.

Chris

Its a shame

I was looking for positive input into this project (but if people insist upon contributing without reading what the topic is about then all is not lost)

But then to go on to agree with another poster who is in the same posistion mindless when their attention is drawn to it beggers belief:rolleyes:

atb chris661
 
The difference between B and C is how high the tweeter will be. The desired height depends on taste. Most people use something around ear height. A has a big horizontal center-to-center distance between the 10" and the tweeter, which makes it a less favorable choice.

I happen to also have tried open baffle below 1 kHz (10" woofer) and monopole above (Dayton H10RW waveguide, 75 degrees round). I agree with chris661 that it sounds weird. First I blamed it on the waveguide, that it narrows as frequency increases. But then I added a second waveguide facing the rear, wired in opposite phase to result in a quasi dipole tweeter with similar directivity (albeit narrower). It made the speaker sound so much better. I abandoned the project because it resulted in a speaker that was too big and expensive.

You make me curious why you want to use all 10, 12 and 15" woofers. Why do you want that?
 
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