Hestia OB, an ambitious low cost, 3-way OB design

motosapien · « **Reply #180 on:** 10 Sep 2014, 01:37 pm »

Mat - drop me a pm if you have a pair of the vifas.

matevana · « **Reply #181 on:** 10 Sep 2014, 05:57 pm »

PM sent on Vifa D19's

motosapien · « **Reply #182 on:** 13 Sep 2014, 08:14 pm »

Going to give this design a whirl. That 10" mcm just has to sound impressive. Plan to do something different for the base driver though. Maybe a 12" woof in a Z frame that will also raise the ob portion up to ear level. I'll keep ya all posted.

OB_Newbie · « **Reply #183 on:** 16 Sep 2014, 05:59 pm »

Hey Moto,
I got going OB with the original Hestia... a fantastic way to get into OB and test the waters with a small investment!! I have an extra pair of MCM's around new in box and used (like new condish but broken in). For the money you can't beat them and still listening to dual 10's below a Tang Band W4-1879 full-rangers at this time. Dedicated plate amps drive the dual MCM's and a Behringer DCX2496 for xover duties. A class D amp to drive the TB. I still can't believe how good this sounds.

As an option, I might have enough of the woofers to do 3 10's per side (dual for bass freqs). I think the transient response of small drivers like the dual 10's is an improvement over using a larger (with considerably more moving mass) 15" woofer. IMHO.

Good luck with the build... if you have not done an OB yet to are in for a real treat!!!

Regards,
Rich

motosapien · « **Reply #184 on:** 16 Sep 2014, 10:33 pm »

Rich - I built a pair of John Busch's manzanitas so I have been exposed to ob. Hoping to bring more of the midrange out and the Hestia looks promising in that respect. I may be off base but I think the mcm should have the transients covered if it is rolling off down at 90. Initially I will just run the top and see how I like that before I integrate the base drivers.

Life is good when you are starting a speaker project!!!

OB_Newbie · « **Reply #185 on:** 17 Sep 2014, 12:13 am »

The Manzanitas, they were second on the list initially. Never heard them but surely sound nice.

Thats a good approach Moto... see how it sounds and go from there. And yeah... nothing like the start of a new build my friend!!!

hieu_ma · « **Reply #186 on:** 19 Sep 2014, 01:46 am »

Quote from: matevana on 9 Jul 2012, 09:07 pm

Baffle dimensions showing Right Panel (Left is mirror image)

Dear Matevana and Hestia OB fan

Thank you very much for sharing this very interesting OB schematic because the baffle size is very suitable with my small listening room and I like OB sound.

Could I replace the mid speaker in your plan with Philips AD9710M/01 (alnico version)? I have these Philips speakers now and I love the mid range of them. In this case I dont need treble speakers any more because the Philips could manage quite well the HF in my own opinion. If Philips 9710 is ok, should I think of other woofer such as Eminence Alpha 12"?

How do this idea sound to you? Would I still get the optimal sound from your Hestia OB plan or will it change a lot when I use AD9710M/01 for the mid range?

I would appreciate any comment and suggestion from you.

Hieutl

matevana · « **Reply #187 on:** 19 Sep 2014, 04:50 pm »

Hi Hieu-ma,

The original Hestia design is an easy build and fairly straight forward. The baffle size, driver selection and crossover components were all designed with the specific drivers in mind. That being said (and I am not familiar with the particular Philips driver you mention) changing even one component will likely impact the finished product. Part of the fun in experimenting with OB is the ability to easily create new baffles and try new things. Please let us know how the Philips midrange sounds in the Hestia design.

hieu_ma · « **Reply #188 on:** 24 Sep 2014, 08:50 am »

Dear Matevana
Thanks for your guidance. I will keep searching for a suitable OB plan.
All best

motosapien · « **Reply #189 on:** 2 Oct 2014, 05:06 pm »

I have the mcm and vifa drivers in hand. The mcm driver sounds great with just the specified cap across it. I can tell it is going to sound like I had hoped. I'll keep you all posted as I progress with this design. First a quick mock up on mdf and then probably Baltic birch. If the results are stellar I may spring for some copper veneer.

matevana · « **Reply #190 on:** 3 Oct 2014, 05:41 pm »

You have the added advantage of the original Vifa D19's made in Denmark. I think you are really going to like the combination!

Squidspeak · « **Reply #191 on:** 5 Oct 2014, 01:08 am »

Matevena, I will be demoing the Hestia design at NY/NJ DIY in Brooklyn on Nov1.2014
Awhile back I posted about using the Dayton 15" instead of the 10" while keeping everything else
true to the original. I also loaded the 15" in an H frame. Finally finishing this project I started more
than 2yrs. ago. The Hestia Grande will make its debut, thanks for the design.

matevana · « **Reply #192 on:** 5 Oct 2014, 07:15 pm »

Hey Squid,

My brother lives up in Brooklyn. Maybe I can have him check out the show. Can you post a picture of your completed project?

Squidspeak · « **Reply #193 on:** 5 Oct 2014, 07:49 pm »

Matavena, I will take some pics at the show. Info about the show is available on the PE Tech Talk
forum.

motosapien · « **Reply #194 on:** 6 Oct 2014, 12:41 am »

Hey now! I've got one up and running. No bass driver yet so I've got the mcm driver running without the coil so it is making bass below 90. Very nice sound stage and midrange clarity. Amazing vifa tweet that can sound so good with such a simple filter. And considering I only have a cap across the mcm it is equally impressive. I strongly concur that driver selection is particularly critical for an open baffle system.

The mcm must be making bass into the 40's. This would be a good apartment speaker just the way it is. I will certainly be adding some kind of base driver on the floor below it though ( like to hear Phil Lesh drop live base bombs ). M - you did a splendid job with the Hestia. It is my kind speaker and I'm well pleased I decided to give it a try.

It will be awhile now before I finish this project. I will post pics when I do.

matevana · « **Reply #195 on:** 7 Oct 2014, 04:46 pm »

Awesome! That just makes me wanna dig up some old Jerry Garcia stuff!

Squidspeak · « **Reply #196 on:** 27 Oct 2014, 09:10 pm »

Matevana, I am ready to build x-overs for this and found conflicting info ;page one you have
C1 and L1 going to the MCM mid/woofer and C2 and L2 going to the Vifa tweet, then on pg9
they are reversed. Which one is correct?

matevana · « **Reply #197 on:** 28 Oct 2014, 12:12 am »

Sorry Squid... didn't mean to confuse. The values on page one are indeed correct. C1 and L1, (7.5uf and 1.80 mH) respectively go with the MCM driver. The later diagram on Pp 9 was a generic attempt to show a close-up of the schematic; please disregard the labeling there.

Folsom · « **Reply #198 on:** 28 Oct 2014, 01:18 am »

This looks fun. How sensitive is it? How far from the wall does it have to be? How good do you guys think it is?

Any thought on using the T26SG tweeter? It's pretty good and doesn't exceed price, but I dunno if it'd pair well.

matevana · « **Reply #199 on:** 28 Oct 2014, 11:16 am »

The T26SG is a nice tweeter but is far from a drop-in replacement. It is quite a bit more sensitive and has a different nominal impedance, so the x/o will need to be reworked. Sonically it is more detailed than the D19 but not quite as warm, based on my recollection. The D19 also has excellent off-axis response which is a hallmark of this design. If you are going to change the tweeter I would recommend either the Seas 19TFF1, the Vifa X19 or the Scanspeak D2008 which will all maintain the original characteristics of the Hestia design.