[caribhifi]

I am brand new to the site as well as speaker building. It took me a while to realize that I love open baffle speakers. It started with the DQ 10's, then the quad esl 63's, and now the Ohm Walsh 4x0 speakers. I have owned other speakers however I enjoyed these the most but it was only recently that I have put it together that they are all open baffle speakers.

So I did what any normal self respecting audiophile would do, build my own. I decided on the Wild Burro Betsy with the open wing baffle.

It sounded great at first because I was amazed at the level of sound from such a simple design.

BUT HERE LIES THE PROBLEM. After careful listening I noticed that highs were missing from some recordings as well as the speaker seems to be SHOUTING at the upper freqencies.

What am I doing wrong? or what can I do to rectify the problem?

[Russell Dawkins]

Ohm Walsh 4x0 open baffle? I thought all Ohms used a box and were omnis.

As to missing highs and shout, I suspect you are experiencing the limitations of the driver, and the single-widebander-no-crossover approach in general.

The real solution probably lies in the addition of a decent tweeter and a crossover to roll the top off the Betsy. That and/or going for a higher quality main driver (and a tweeter!). You would still reap the benefits of open baffle.

[matevana]

Aside from what Russel mentions you could play around with a notch filter on the Betsy's.  The goal here would be to notch-out or attenuate the offending mid band frequencies that exhibit shout. In doing so the relative loudness of the lower and upper frequencies (on either side of the notch) will appear enhanced.  Sometimes you can get lucky and salvage the driver w/o adding a separate tweeter. If you Google 'notch filter calculator' there are several online sites that can help predict the component values you will need to make this simple filter.

[caribhifi]

Thanks Guys.

 Maybe I will try the tweeter and cross it at 5000 HZ. I am puzzled  because I see a lot of builds using that driver and no one seems to be complaining.

What other speaker would you recommend? What about the the Nirvana's 10's or 12's full range?


Thanks again for the suggestions 

[zimmer64]

Hi there,

I tried Betsy in the winged baffles as suggested on their web site, as well as in a MJK style baffle with an Eminence 15A helper woofer. The late version was implemented active biamped using a miniDSP as x-over. I did in room measurements using REW and the mic that miniDSP sells. My ears and the measurements told the same story. Mid range shout and down in the high frequencies. I had to use significant amounts of equalization to make Betsy sound balanced. In the end I took them out. I think one needs a tweeter from 5k upwards, plus you need to tame the mid shout at about 2.5k (if i remember correctly).

I am now using a Fostex FX120 and the Alpha woofer in an open baffle, again biamped and a miniDSP between pre and power amp. That setup is very pleasing to me and produces a live like sound on good recordings. Here is a bit more info: http://zimmer64.wordpress.com/2013/12/11/open-baffle-using-fostex-fx120-and-eminence-alpha-15/
I will rebuild the exact same baffle, but construct them a bit differently and have them professionally high gloss spray painted to mach my SO's house decoration scheme

I have also looked at the Nirvana's, but have not tried them (My wife kills me, if I buy more speakers... If you do, please post your results.

Have fun

Michael

[caribhifi]

Hi Zimmer

Thanks for that post it makes me fell a lot better knowing that I am not the only one with that experience.

I will look at the specs for the Fostex FX 120 as well as others.

I will let you know what I end up with.


Thanks

[Tyson]

Grab a mini dsp, best investment ever.  Will do what you need and much more.

[Folsom]

Better caps helped me with some OB's before.

[caribhifi]

In my first post a said that the Ohm Walsh 4 x 0  was open baffle. Russell said that he didn't think that they were, so I called Ohm Acoustics and I was told that they were not open baffle but NO BAFFLE only the bottom is ported. Maybe that will explain why the are so open on top.


Thanks Russell