The best affordable DIY open baffle loudspeaker I've listened to so far.

0 Members and 1 Guest are viewing this topic. Read 119349 times.

panomaniac

Thanks for posting that, John.  Nice to see the reverse polarity plot.  The circa 2.5K glitch is odd and may be a baffle artifact.  What do you think?

Martin, right.  Published specs.  I believe that John has measured T/S parameters for the actual drivers and may be able to post them here.  It's will be interesting to see what difference that makes.

JBspeakerman

Here is the PE GRS 15 WT3 sweep taken with  the driver on the baffle.




JBspeakerman

Here is the Vifa WT3 plot mounted on the Ultra baffle.  No crossover with the Vifa or the previous GRS 15 post.







JBspeakerman

Some more measurements...

Here is the first of more Holm in room snaps for the Ultra.  This one shows the GRS 15 on baffle at 8' on axis with a MLS Sq noise sweep (reddish brown trace) and standard log sweep.  No crossover inductor.  The lower end below about 100 Hz is not acurate, as in too smooth.




JBspeakerman


Here is the Vifa on Ultra baffle, no crossover.  Again, the very low end is not representive of reality.  Blue trace is log sweep, Redish brown is MLS Sq noise.  The spikes at 450 & 1.8K are anomalous noise.






panomaniac

Thanks John for the graphs.  It would be nice if you could repost them not gated, but maybe at 1/12th octave smoothed.   The gated measurements always confuse me.   :?

scorpion

Hi,

I was away with my 99 year old mother for Christmas so I didn't send any comment during that time.
Regarding Martins reverse engineered speaker and my sim. There is a close resemblance, both about 20 dB down for a hole in the response. Martin is much more near the thruth by beeing able to take into consideration both the step down resistor value and the BSC-circuit, also in step down duty for the VIFA. Martin is of course able to enter such values in his software, where he knows the entries. But that we should be thankful for. I would be extremly surprised if the new Manazanita speaker would sound any where equal, with its Phantom Sounds reliance, to a more traditionally (ie in the MJK-style) constructed OB speaker.

To me this is not taking care of the fine virtues of the surprisingly good VIFA engine. I shall not speak over the GRS woofers, I have done that once alredy and that's enough.  :)

/Erling

panomaniac

She's 99? Very cool! Hope she has a happy 100th.  :thumb:
I would be extremly surprised if the new Manazanita speaker would sound any where equal, with its Phantom Sounds reliance, to a more traditionally (ie in the MJK-style) constructed OB speaker.
Then why does it measure so flat?  John has shown several raw measurements and it's pretty darn flat. No hole, unlike the sims.  Why?  Is he measuring wrong, or the wrong thing?

scorpion

Thanks Pano, I hope she will last until the 28th of June this year for her 100th birthday. I think she will.
Regarding the Manzanita I will not give any more comment. I think whats given is enough.  :)

/Erling
« Last Edit: 13 Jan 2012, 02:52 pm by scorpion »

MJK

  • Full Member
  • Posts: 468
    • Quarter Wavelength Loudspeaker Design
Then why does it measure so flat?  John has shown several raw measurements and it's pretty darn flat. No hole, unlike the sims.  Why?  Is he measuring wrong, or the wrong thing?

I thought the measurement and the sims aligned very nicely considering all of the assumptions required. The first set of measurements look very flat because the scale is so large. The original measurements and the sims seem to both show a wide 15 - 20 dB dip in the mid range. Correlation looked really good to me.

Martin

panomaniac

Yes Martin, better agreement with your sim, for sure.  I would be nice if John could post the T/S parameters of the actual drivers for another, better pass of simulation.

JBspeakerman

Pano

Do you want the T/S values with the drivers mounted on the baffle or free air?   T/S values or complete WT3 sweeps & info?

panomaniac

I think for Martin's sims free air is needed.  I don't know if he needs the impedance curves (or numbers) but I guess it couldn't hurt. The exported numbers could be zipped and posted.
Post the free air T/S and let's see what Martin says.  The DCR of your coils might help, too.  Thanks!

MJK

  • Full Member
  • Posts: 468
    • Quarter Wavelength Loudspeaker Design
Posts 61 and 62 contain T/S parameters for the drivers. I checked them for consistency and everything matched. Putting these values into my original sims did not change the results significantly. The dominant contributor to the dip in the middle of the SPL curves is the fundamental crossover design, not the driver T/S parameters. I don't think this set-up will sim or measure flat, but if it sounds good who cares.

JBspeakerman

Pano & Martin

Thanks for you input.  I am still tweaking negative and positive polarity crossovers.  Mainly working the HF trap - pad values.  Balancing what measures good with what sounds good and trying to understand crossover - accoustic relationships.  Once I have taken things as far as I can, will post updated crossover(s) and measurements.

bjuck57

  • Newbie
  • Posts: 2
My new Manzanita Ultra build.
Hello John and fellow diy builders. I have had the great fun of building the Manzanita Ultra's the last couple of weeks. I hooked up the speakers to my tube pre-amp and B&K ST202+ power amp yesterday night. First impressions are very good, with a very impressive bass and homogenous overall sound. Very low and clean bass notes. This is only my first listening impressions with new drivers, no proper burn-in period done. Thank you so much John for sharing this exciting and elegant design with the diy community! \Hans in Holmsund, Sweden.








Mmaxed

  • Jr. Member
  • Posts: 52
Nice looking build!  Keep us posted on hoe you like the sound.

underdawg

  • Industry Participant
  • Posts: 358
very nice build indeed

bjuck57

  • Newbie
  • Posts: 2
Here comes an update after 150+ hours with my Ultras. I'm VERY pleased with the performance of the Ultras. I've becomed addicted to the smooth and open sound and the very powerful, low octave bass. I heartily recommend building or buying these excellent speakers from John (www.manzanitaaudiosolutions.com).
\Hans in Holmsund, Sweden.

JBspeakerman

Hans....

Thanks for sharing your opinion of the Ultra build! Know it was a lot of work to obtain the GRS in Sweden.

I fear a lot of potential builders have difficulty believing how good such a simple design and build can be. And they worry about the intrinsic low efficiency. However, if you run the numbers and measure most designs that can really play flat into the upper 20's, you will usually find one of two outcomes.

1) The enclosure is the size of a double door refrigerator, or... 2) The true efficiency is similar if not less than the Ultra. As best I can measure, the Ultra is around 84-85 dbw. And that is all the way down. No roll-off!

Provide a clean 20-40 watts per channel in a typical domestic setting.... for most music, you have more than enough output.

Funny thing about the Ultra is the tonal purity of the bass. It's all most creepy to hear true fundamentals with out the usual doubling nearly ALL speakers regardless of design produce below 50 Hz or so. That is why the Ultra low end is SO addictive... as you observered.
__________________
Commercial Website: http://www.manzanitaaudiosolutions.com/index.html