[pieral]

Hi, this is my 1st message, i'm new to OB design, and i'd like to give it a try.
I'm quite familiar with vented speakers design, but i don't know anything about OB theory and practice.

i have these speakers to mount :
- 4x beyma 12b100r (12").    >300Hz 12dB/o
- 2x PHL 2540 (10") >300Hz<2KHz 12dB/o
- 2x ess amt. >2KHz 12dB/o
(- tri-amplification + active crossovers)
(- The listening room is about 30m²)

- do you think that OB is a good option?

- do you have a link or more to help me calculate the dimensions of the panels, the placement of the speakers...

- what do you think about this (totally improvised) design? :



thanks for your help!
Pierre, France

[Rudolf]

Hi Pierre,

the proposed panel dimensions are allright - good choice to start from.
Driver suitability ranges from 90-50%. The AMT is a good choice - as is the PHL, which could be smaller. A 8" or even a 6" with a generous Xmax would have been better. Qts of the Beymas is quite low. Be prepared to use some EQ added to the Xover. Xmax will only allow less than spectacular response levels.

If you only want to get your feet wet - you should very well be able to see what OB is all about.
If you want to replace an existing system and don't yet own the proposed drivers - there are better choices for midrange and bass.

Try to keep the AMT as close to the midrange driver as physically possible. And let the upper baffle edge end between both drivers.

Rudolf

[pieral]

hi Rudolf, i've made a mistake, the PHL is a 8" driver.
i already have all these drivers, recently bought for un upgrade of my existing baffles.

i have tried the PHLs in OB, and liked the result, so i was thinking of trying the whole thing in OB.

But as you said the Beyma is not suited for this, and deep bass is very important to me.

i think i'm gonna let the beymas vented, and the PHL in OB.

thanks for your advises!

[JohnR]

Hi, you may like to check your baffle esp for the mid in The Edge simulator. You may find cutting off the top corners helpful. (The tweeter may like it too.)

This one - http://www.audiocircle.com/index.php?topic=87150.0 - was a bit similar to yours.

[studiotech]

Looks really nice, but consider the BG Neo10 in place of the PHL and you are all set.  Much more neutral than those PHL, those maybe not as "exciting sounding"

Greg

[ttan98]

Hi,

You will like your PHL, I use the 8" older model, 2460, it is rated at 95dB and I can get it down to 200Hz. I use the Hi-Vi 8RTII , not as good your AMT, that will do for me, easier to x-over it is also rated at 95dB. I like my combo.

Enjoy yr speakers when they are completed.

[pieral]

Hi, the phl 2540's sound is great, very neutral to me, but i don't know the BG Neo10 ...
to me a perfect couple with the amt above 2Khz.

Where can i find the EDGE program? sounds interesting!

[versus rider]

Hi Pierre have pm.d you

[djn]

I have had many Big Heil AMTs and they are one of the best tweets I'v ever heard.  If you don't know their sound, you will be vary happy with them.  I like that you have a midrange driver in there.  The AMT will go down to 800hz and should not be crossed any lower than 1200hz but down there I think they sound very thin.  Crossed above 7khz and they are amazing.  Good luck.  I can't add anything else about your design.  New to OB myself and built one pair.  I can say that I love the sound.