Need help designing a new cabinet/baffle with proper driver to baffle placement.

[Big_Bill]

Hello Gent’s, I have been remiss as it’s been sometime since my last post. Today I’d like to solicit advice on a new baffle design/driver arrangement (woofer/mid/tweeter spacing and placement on the baffle) in order to best address combing and diffraction loss issues for my 3 way DIY speakers. I’m having trouble wrapping my head around this and I sure could use some help.

Thanks in advance, Bill!


The driver information is as follows:

Vifa D27TG-05-06
D27TG-05-06 | Tymphany

Peerless 832873 HDS 5-1/4" Woofer
Speaker driver

Dayton DC380-8 15" Classic Woofer
http://www.parts-express.com/pdf/295-325s.pdf

The second order L/R passive crossover points (theoretical) currently in use are as follows:

Dayton: Low Pass 300 Hz
Peerless: Band Pass 300-3000 Hz
Vifa: High Pass 3000 Hz

[Inductor]

It looks good, nice 5 Inch Mid. You need to curb the curve on the woofer totally >300/500Hz then. It doesn't have very soft natural attenuation on high frequency for a xover with the mid, that's the problem. It just needs more xover components and testing/simulation... From your post it's just baffle/box design that you need.

[Big_Bill]

Originally Posted by Inductor

It just needs more xover components and testing/simulation.

Perhaps, however current baffle placement is wrong on many levels. These started as a 4 way speaker project which almost everyone told me would be a nightmare (and they were). They also told me my driver/baffle placement was off (yet I insisted on re-using some existing, poorly designed/executed cabinets). To further illistrate my point I'll attatch some pics.

[Inductor]

Originally Posted by Big_Bill

Perhaps, however current baffle placement is wrong on many levels.

Ok Bill, the baffle/speaker looks great (OB?), congratulations, you are ready for a new one... good What about the xover then

[Moondog55]

Hi Bill
Well first off tell me/us what is "Good" about the current setup.
Tell us/me what you perceive to be "Bad".
I never did get the feedback on how the .5 woofer helped.

First thing to do is determine what is the biggest box that has acceptable WAF

[Moondog55]

Can you afford the extra amplifier to go active??

[wintermute]

Hi BIll,

BDS (Baffle Diffraction Simulator) will help you get an idea of how the driver placement (and baffle size) will affect the freq response. I don't think it will help with combing though.

From memory (and I could well be wrong, so check!!) The closer together the mid and the tweeter the less of a problem combing will be.

Tony.

[Moondog55]

Get the drivers aligned in the vertical; get the mid and tweeter as close together as possible, don't cross between 300 and 3000. try and use low order XO if possible Go active if possible. Same starting advice as earlier

[Francec]

Bill,
I use the Peerless 832873 from 300 to 3,000 Hz in an active 3 way, with LR 4th order active crossover. Very nice.

Frank

[Big_Bill]

Originally Posted by Moondog55

Well first off tell me/us what is "Good" about the current setup. Tell us/me what you perceive to be "Bad". I never did get the feedback on how the .5 woofer helped.

The Dayton worked just fine as a .5, however I discovered that the Adore Audio AV8 was "beaming" (?) so I removed it from the circuit and changed the x/o to bring the Dayton in at 300 (where the peerless is crossed over). I like them in this x/o configuration although with the 15 running up to 300 you can hear a "separation" (?) in the frequencies while listening due to the distance on the baffle between the mid/tweeter and the 15, I think?

Originally Posted by Moondog55

Can you afford the extra amplifier to go active??

Oh my, no!

Originally Posted by Moondog55

Get the drivers aligned in the vertical

This is part of what I wanted to know.

Originally Posted by Moondog55

get the mid and tweeter as close together as possible

I will get them closer together and vertical this go round. I would like to know if the mid/tweeter should be "shifted" to one side or the other of the new baffle (kind of like those 70's multi-way speaker designers did) or placed dead center above (and as close to as possible) the Dayton?