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

matevana · « **Reply #280 on:** 28 Jun 2015, 06:26 pm »

Very cool. What do you think of the XT-19?

bear-hifi · « **Reply #281 on:** 12 Jul 2015, 01:53 pm »

I like it and for the money it's really good.

Oktyabr · « **Reply #282 on:** 23 Jan 2016, 06:22 am »

I'm tempted to build the top two thirds of this design and place it over my MLK spec'd 18" Goldwood H-Frames. Has anyone else experimented with this setup?

I have separate amps for the H-frames and the tops (currently hosting an 8" full ranger) and my main concern is a greater distance from tweeter (ear level) and the center of the 18"s. Is this concern justified?

Thanks in advance!

matevana · « **Reply #283 on:** 23 Jan 2016, 03:42 pm »

Quote from: Oktyabr on 23 Jan 2016, 06:22 am

I'm tempted to build the top two thirds of this design and place it over my MLK spec'd 18" Goldwood H-Frames. Has anyone else experimented with this setup?

I'm in the process of redesigning the crossover to wind up with a lower component count; working with the resistance of select caps and coils to eliminate separate resistors for level matching. This also necessitated a woofer change to the Peerless SLS line for the top section's lower midrange duties. The total component count will now be one inductor and two caps, which is quite unique for a 3 way system. The new design also has all three drivers wired in phase.

Quote from: Oktyabr on 23 Jan 2016, 06:22 am

I have separate amps for the H-frames and the tops (currently hosting an 8" full ranger) and my main concern is a greater distance from tweeter (ear level) and the center of the 18"s. Is this concern justified?

What is your listening distance?

I have used the top sections with H and U frames as well as sealed enclosures. They sound good with any bottom section that maintains tight control up to around 180 Hz.

Oktyabr · « **Reply #284 on:** 23 Jan 2016, 05:46 pm »

Pretty typical, I think. 9-12 feet with the centers of the H-frames six feet apart and pulled out from the back wall some. I love my full ranger tops for moderate listening levels and they have kept me pretty happy for a few years now but on occasion I like to turn it up and their power handling (95db @1w/1m, 30w rated) reveals stress and distortion as I push their upper limits. I'm hoping this design might flesh out the lower mids and maybe give my system some extra headroom for when things get noisy

matevana · « **Reply #285 on:** 23 Jan 2016, 11:43 pm »

Dispersion on the XT19 tweeter is pretty good. At a listening distance of 10 ft you shouldn't have a problem. They can play fairly loud w/o any breakup. Your bottom cabinets will likely become the limiting factor if you try to push them.

Oktyabr · « **Reply #286 on:** 23 Jan 2016, 11:52 pm »

Ha! That would be OK then. A pair of 18" in H-frames at loud volumes feels like they are trying to move furniture and internal organs. I'd be quite happy if they were the weak spot in my system

Oktyabr · « **Reply #287 on:** 24 Jan 2016, 04:47 am »

So what IS the preferred parts list now? Peerless or MCM? D19 or XT? Big caps or an extra choke? I really, REALLY want to build something new but can't afford to throw away money... especially on passive XO components.

matevana · « **Reply #288 on:** 24 Jan 2016, 11:27 am »

Sorry. I was referring to the current Hestia V designs. I have not attempted to modify the original design as I no longer own them. The original design is an easy build and provides decent results for the effort. All of the components and values remain the same.

Oktyabr · « **Reply #289 on:** 24 Jan 2016, 06:38 pm »

Thanks! I think I'll give them a whirl.

Oktyabr · « **Reply #290 on:** 14 Mar 2016, 07:27 pm »

Anyone have any videos of the original Hestias (or the newer versions) in operation?

JohnCZ · « **Reply #291 on:** 1 Dec 2018, 12:53 am »

Hey Matevana!
Finally completed my Hestia OB (98%). As you can see from the pic I've doubled up the woofers to get a little more low end and elevation on the tweeter. My previous OB project had an Emenance alpha 15, but l never seemed to get a full sounding low end. Using the 2 low end drivers here produce a much better low end.
As I was finishing up one of my Yung 300 plate amps developed an issue, so l had to put together a low end filter and drive the woofers on the other speaker output on my receiver. I'm using an iron core 4.7 inductor and a 33 uf cap. I just guessed on the filter values and used what l had from other projects. Overall the sound is great, but the low end dominates a bit. I'm surprised at how much more bass I'm getting from the 2 10s as opposed to the alpha 15.

Thanks for all you do for the DIY community and your research.
John

Bumpy · « **Reply #292 on:** 1 Dec 2018, 07:54 am »

I cant find anyone to answer this thorny question, so will ask it here to the designer and builders of this OB.

"Why when building an OB and all options are open to you, do you select a mono pole tweeter and throw away all the advantages of dipoles

I am not trying to start an argument or even criticise, but would dearly love to know the answer as I am modifying my own OBs and have placed great importance on trying to achieve dipole tweeters. Perhaps I am wrong.

Poultrygeist · « **Reply #293 on:** 1 Dec 2018, 01:02 pm »

fewer choices?

Bumpy · « **Reply #294 on:** 1 Dec 2018, 01:33 pm »

Quote from: Poultrygeist on 1 Dec 2018, 01:02 pm

fewer choices?

Totally agree with that, but is it really a compromise to go with a mono pole tweeter. I would love someone to defend the decision so I can understand the choice on SQ criteria

matevana · « **Reply #295 on:** 1 Dec 2018, 06:00 pm »

Quote from: JohnCZ on 1 Dec 2018, 12:53 am

Hey Matevana!
Finally completed my Hestia OB (98%). As you can see from the pic I've doubled up the woofers to get a little more low end and elevation on the tweeter. My previous OB project had an Emenance alpha 15, but l never seemed to get a full sounding low end. Using the 2 low end drivers here produce a much better low end.

Hey John! Nice job and I'm glad you're enjoying your new setup. I'm on a guick lay over in Guangzhou so I only have access to a calculator on my phone, but assuming your two 10" drivers are wired in parallel, the cap and coil values you mentioned should net around 200 Hz, 2nd order. That's in the ballpark and you could always experiment later. Talk more later when I get back!

matevana · « **Reply #296 on:** 1 Dec 2018, 06:10 pm »

Quote from: Bumpy on 1 Dec 2018, 07:54 am

I cant find anyone to answer this thorny question, so will ask it here to the designer and builders of this OB.

"Why when building an OB and all options are open to you, do you select a mono pole tweeter and throw away all the advantages of dipoles

I am not trying to start an argument or even criticise, but would dearly love to know the answer as I am modifying my own OBs and have placed great importance on trying to achieve dipole tweeters. Perhaps I am wrong.

The original Hestia was a hybrid OB and made use of drivers that I had worked with previously. It was more 'proof of concept' that was easy to build and modify... and light on the wallet.

Bumpy · « **Reply #297 on:** 1 Dec 2018, 08:45 pm »

Quote from: matevana on 1 Dec 2018, 06:10 pm

The original Hestia was a hybrid OB and made use of drivers that I had worked with previously. It was more 'proof of concept' that was easy to build and modify... and light on the wallet.

Thanks for contributing to the debate. So can I assume that if costs are equal between tweeters then a dipole is better suited to an OB baffle, but if one is prepared to spend more on the monopole it may well outperform the cheaper dipole.

matevana · « **Reply #298 on:** 2 Dec 2018, 01:32 pm »

Quote from: Bumpy on 1 Dec 2018, 08:45 pm

Thanks for contributing to the debate. So can I assume that if costs are equal between tweeters then a dipole is better suited to an OB baffle, but if one is prepared to spend more on the monopole it may well outperform the cheaper dipole.

Likely depends on who you ask. All of Linkwitz's mainstream designs (Phoenix, Orion, LX-521) used monopole tweeters in either single or back to back configurations. He commented on experimenting with various dipole drivers (both dynamic as well as ribbon, AMT, etc.) and the lack of dynamics associated with some of these.

My most recent experiments make use of a well behaved full range dynamic driver mounted in an open baffle, coupled with a rear mounted, up-firing, monopole tweeter (crossed very high, i.e., 20kHz first order) for ambient sound.

Bumpy · « **Reply #299 on:** 2 Dec 2018, 04:57 pm »

Thanks. That Linkwitz stuff makes for interesting reading. Out of interest what tweeter are you using that gives worthwhile output above 20KHz?