My open baffle dipole with Beyma TPL-150

[cuibono]

If you add foam to the edges, things get even better!

[badman]

I suggest you use different chains for the hanging woofer- there are chains sold within vinyl covers that would be less likely to ring or rattle in use, plus would allow you a built-in damping layer at the suspension points.

[CLS]

Or, steel wires also do a very good job. I'm using steel wire of about 3mm O.D. to suspend my horns. I think 2 or 4 wires in this size are good for 20kg or more. Organizing the drivers in groups and separate the loads, these skinny-looking stuff should be fine.

[StigErik]

I dont have problems with ringing or rattling with the chains, but I do get your point... Chains are very easy when prototyping at least. Steel wire would probably look a lot nicer for a final "production" speaker. I'm still at the prototype stage here, so...

I just got a new truckload of drivers from Beyma, including a lot of 12". Will try to replace the 15" with two 12" to see if that works well. There is room for two 12" below the mids and tweeter. That will give me some more cone area in the low mid/upper bass (50-300 Hz). It will also look a lot slimmer.

Here a sketch of it, with one 21" subwoofer in H-baffle:

[Russell Dawkins]

I like the proportions of the 2-12s. Is the current plan to use the H baffle 21 as a sub with the 2-12s?

It must be nice to have numbers of drivers flowing past as you do!

[Overkill Audio]

Hi Stig Erik,

Just wanted to say congratulations, you are really developing something special here. I really admire your relentless work ethic " Build it and they will come" combined with enough test and measure to move you on to the next stage.
This really is what high end audio needs and this thread shows the kind of collaboration and DIY spirit that NASA and SETI employ with their global network of DIY researchers looking for prime numbers and signal continuity, beautiful ...!!!
Just a suggestion on the Beyma drivers as you are the Beyma Dude round here...!
The 15 inch Neo 15LW30 is a real gem, (up there with the Volt 2500.4 and Beyma 12LX60). The 15LW30 combines 90% of the Volt speed with really powerful low end, even better than the 12LX60, and its beautifully smooth all the way out to 2Khz. In fact plus or minus 1.5dBfrom 100Hz to 2 KHz!
I totally understand that two 12 inch will be slimmer and a bit more cone area, personally I use a VPL wing and baffle with a single 15 inch ( Precision Devices PD158) to avoid having to use any EQ boost in the 80Hz to 400Hz band that it covers.
Anyway your doing an amazing job and I look forward to the finished design, I would love to pop over in the Spring if you have some spare time.

Cheers

Derek.

[StigErik]

Originally Posted by Russell Dawkins

I like the proportions of the 2-12s. Is the current plan to use the H baffle 21 as a sub with the 2-12s?

It must be nice to have numbers of drivers flowing past as you do!

Yes and yes

The H-baffle sub will cover 25 Hz to around 60 Hz, depending of how low the twin 12" will go without complaints.

[StigErik]

Derek,
I will check out the 15LW30!

You are of course most welcome for a visit. I live just one hour away from Oslo airport, so its easy to get here.

[StigErik]

15LW30 is on Beyma's "discontinued" list.... any other suggestions, Derek?

[Jonasz]

Originally Posted by sendler

That's a lot more bottom end below 2k than I usually see posted in the measurements of a Neo3.

I use them in dipole mode down to 1440hz (in a baffle) and it sounds great! No measurements though, just my ears...

Btw, the Neo3 has more bottom end without the cup than with it. I remember seeing measurements from Zaph years ago.