Build therad: OLA-WG 2.5 - a 2.5way with SB midwoofers and a Bliesma tweeter

[Bear]

Nice work!

[JonMarsh]

Uh, didn't you forget something?

Very good work, indeed! :T

But...


:uhoh:


There are these nice reserved blocks at the beginning of this thread...

In place for critical information to share...


Which are still...


very, very empty!

:huh:

[ergo]

Point taken Mr. Moderator

I do have most of the content for it and will ask my friend for his latest Xover variation too (he did lots of trial/listening/trial/simple measurement type work on it. Xovers are still next to speakers outside, but the pair is playing nice and is our other evaluation setup for Purifi amp tuning beside my Wavecor Ardent based system.

I'll be spending 10 night in hotel next week and with a severe jet-lag there is hope I can find time to fill the emptiness up.

[ergo]

Filled in the placeholders on first page...

[JonMarsh]

Filled in the placeholders on first page...

Looking good, Ergo.

As anyone who has tried with the T34 series knows, getting a nice waveguide response is no trivial task-

[Alernex]

I have the T34B-4 tweeters too for use without a waveguide.
Have listened to the tweeters with a quick test setup and they sound just perfect really. Unlike anything I personally heard before.

What I do wonder though. Did you order them without the protective grill or did you remove it yourself?

Thank to this comment only I'm thinking about T34B-4 now. I'll test and share my opinion about them.

[JonMarsh]

Funny thing, I enjoyed reviewing this thread quite a bit, and pondering lessons learned for a similar build I have in mind- revisiting the Modula MT XE, in a 2.5 way with the same seas ER18RNX (have a couple on hand...) but likely the T25A-6 tweeter...

I'm evaluating some waveguide profiles generated using Marcel Batik's "unified" equation concept and profile testing with BEM analysis using ABEC. Should be able to set that up soon, June sometimes, on the Mac Pro running WIN10. Then I'll just have to sweet talk Steve into milling some waveguides after he's got the shop on line.

In the meantime, I may experiment more with the Eighteen Sound XT1086 and NSD1095 1" combo- the initial checks show considerable promise, and speak to the veracity of Eighteen Sounds claims of extensive BEM analysis and verification.

How's your friend enjoying these?

[dar47]

Aw, the modula MT XE. I know you have said the world doesn't need another 2-way but there seams to be a lot of new big speaker DIY designs going on out there and not a lot of small 2-ways with new drivers. A new modula MT with say T34BE and the new purify mid woof might get a lot of people excited. I have only seen a purify 2-way with odd choice tweeters.

[JonMarsh]

Aw, the modula MT XE. I know you have said the world doesn't need another 2-way but there seams to be a lot of new big speaker DIY designs going on out there and not a lot of small 2-ways with new drivers. A new modula MT with say T34BE and the new purify mid woof might get a lot of people excited. I have only seen a purify 2-way with odd choice tweeters.

Funny you should mention that... Steve is a fan of big boy speakers, too- you should see the attention he pays to the Magico reviews!

But, today I sent him some LF modeling data on a couple of possible Modula configurations- one called the PWB, and the other would be the PWXT. "P" stands for PuriFi, as in 6.5" long throw woofer (we've got about 8 on hand, but so much stuff going on...); W stands for "Wavecor", as in Wavecor PR223BD02 passive radiator, "B" stands for BlieSMa, as in TB25A-6 tweeter, and XT stands for XT1086 wave-guide with NSD1095 driver.

Picks your poisons... obviously, the TB25A is a simpler more budget friendly approach. Would be interesting to do that with a SMJ style waveguide, but it might be a while before we could get around to that. We have some very good results with RS28a tweeter, and a step up in development tools, but dammit, captain, there's still only 24 hours in a day!

:rofl:

But, to part the curtain on the thinking for the cabinet and woofer and PR, this is the POC modeling in Unibox, 14L net. One PR. (yes, I have stock...)


BTW, this PR is the part used in the yet to be completed and mothballed in storage Kurosawa Dai Katanna...






Yes, this is the PR derived from the woofers used in the Wavecor Ardent.


I think this could be pretty fun, reasonably priced system. Should be clean and gutsy. Of course, reasonably priced is relative. Those wanting bragging rights can update to the T25B-6 tweeter!

My apologies for the minor thread hijacking, to answer your question to some degree. Hope Matt doesn't catch me!

[ergo]

Hi Jon and all,

Sorry for being way too infrequent poster over here, but as it is that sometime life does need more focus elsewhere. Work has ramped up with more accountabilities and we too are starting a 'house build'. In our case we are trying to downsize and eventually move to seaside/countryside instead of the city.

My friend is still actively listening to the OLA-s (augmented with two ScanSpeak 10'' woofers in sealed enclosures and driven my Hypex DSP equipped amp)....

Things turned interesting though as I took him along to a listening session at my other friends place who's latest project is an open baffle, augmented with a bass section and a tweeter for very top end. Other than that an approx 7'' fullrange takes care of most of the band.

This impressed my friend a lot with some of the 'ease of sound' and 'depth of soundstage' etc.... So when I do find time to help we might kick off.

[JonMarsh]

What do they say? The best project is a new project?!

Yes, I truly do understand the issues around finding time- thanks for the response!

[john121]

I did a my own project in VituixCAD 1 timeframe last time and then there was the Wavecor Ardent build in between. Now with VituixCAD 2 I've been dabbling with it but decided to use this opportunity to learn it better and follow Kimmo's process (which I see I failed at first go ... anyhow learning and trying again....

With the new turntable, even though it's manual, it does allow collecting the 3X 0..180 deg data pretty fast. So that's not really a problem. Just have to figure out the rest of the process and get better at that too.

The listening distance will the the usual 2.5...2.7m or thereabouts. My friend has a low long shelf for TV that will also have the speakers on it. The back wall is another 1.8m or so behind the speakers. So room mode wise these will be close to free standing and the only strong first reflection will be the floor/ceiling one. I have pictures of his room, but I'll ask him first if it's ok to post those.

Above diagram is just to help get the distances right for the measurement case and I'm trying to match up the simulation with the true "all parallel" measurement at 1m.

Sorry, double post

[john121]

A new build thread with

Drivers:
2x SB acoustics MW16P-8
Bliesma T34B-4 tweeter.

Concept:
Midwoofers in closed box.
2.5way design (lower woofer helps compensate baffle step, but is rolled off before upper woofer)
Bliesma tweeter mated with a waveguide to optimize the off axis / power response integration with midwoofer.

Other design goals:
It is a known that these speakers will be augmented with subwoofer for frequencies below 80Hz
The speakers must be able to play well also at low listening levels as the "client" - ie my friend likes to listen to music tracks at lower level than an average audiophile I suppose.
The speakers must also handle Home Cinema scenario as that will be an equally important use case and the speakers will be used for music/movies almost equally.

Current progress:
As the furniture and placement in room is known the front panel size is also known to be 700x220mm
I've been printing several waveguide for the Bliesma tweeter and measuring them on this intended front panel
SB midwoofers are also bought and measured. One is currently also on the baffle with a 15.7L plastic pot as a "closed box"
The latter has allowed gathering on axis and upto 180deg off axis measurements for both drivers including the relative phase between them for estimating which WG depth and shape gives the best hope for a good xover integration


A teaser of a current proto stage
[ATTACH=CONFIG]28916[/ATTACH]..

May i ask what you thought of the 6-channel hypex amp after construction and listening. I am going to build one too and would like to hear your thoughts. i hear it is an obsolete amp, how does it compare with say a modern tpa3255

Thank you