Feedback in Open Baffle speakers from non OB users

[Subbu68]

My idea is reversible and non-destructive. That is the driver cannot be harmed or damaged. And it has to be done while the driver is already mounted on the baffle or enclosure. Try different profiles made in wood or plastic, may be 3D printed.

You have to kind of tie the phase plug anchoring the thread / wire on the baffle from four sides around the driver so that the wires do not touch the whizzer or surrounds anywhere and the end of phase plug does not touch the dustcap. You may use very thin strips of wood. Different ways of anchoring, securing phase plug in the right position can be planned. It’s just an idea and is very much workable. (Yes you need to be wary of kids tinkering with that after it’s done)

See the picture below, where a DIYer added a tweeter to an FR. Similarly one can try adding a phase plug. Unfortunately a friend took both of my Fanes drivers and I never got to try one.

View attachment 70151

Thank you...

I will try it out. I have no kid to tamper so no issues. Is there any criteria or spec to size the phase plug? I too saw those non-destructible ideas

 

[drlowmu]

Hello Jenson, You asked !! ,

Everyone looks for something cheap. How about trying to figure out what is THE best overall approach,....... and emulate that ??

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

Let me say that again please :


Everyone looks for something cheap. How about trying to figure out what is THE best overall approach,....... and emulate that ??


- - - - - - - - - - - - - - - - - - - - - - -- - - - - -

There are audio facts of life,........ try as you may.............. to subvert the truth:



1) There is NO single driver speaker that is the best answer.

2) Amps are a HUGE problem. The power amp can NOT have any form of NFB ( negative feedback ) and be satisfactory. It must be directly coupled, two-stage tube, in design.

3) The best overall result occurs with speakers that are 101 dB sensitivity rated. The simplest speaker that can satisfy is a two way. This speaker HAS to be front-horn loaded, a two way. For 94% of venues, an A7-8 ALTEC with minor mods will be the answer, as the world's best existing compromise. It is that way today after DECADES of real world use !!!! Stands the test of time.

4) The two way high sensitivity speaker needs to have BOTH drivers FRONT HORN, I say FRONT horn loaded. Never rear horn loaded.

BOTH drivers need to be both FRONT HORN AND ALSO COMPRESSION loaded.

You got it right............ finally..... Both Front horn loaded and BOTH compression loaded.

It takes a 15 inch woofer,............ always.

Listen to Greg Timber's "retirement " interview in 2022, where he talks about NEVER mistaking a woman in a huge shopping mall, unseen, but playing a grand piano. You can TELL what it is playing - live or reproduced, immediately !!!!!!!!!!!!!!!!!!!!! Which is live playback VS reproduced playback !!!!!!! ??????? GREAT analogy. That sentence, idea, solidified the whole concept to ME after 70+ years, in 2022.

5) The drivers need to be PROFESSIONAL USE made, not consumer grade made....not good enough.

Three professional drivers will do :

(1) Pre-WW2......... Klangfilm,

(2) Japanese ALE,

(3) or ALTEC, even better yet (3a) GPA. ) Those are THE three Professional Drivers.


NOW you know !!!!




5) The amplifier absolutely must employ a " fast as the music " L.S.E. S. power supply, or it won't EVER EVER cut the mustard.

Have fun,

I am .

Jeff

A7-8 / 825, 515B, 802d, 811b. SE DC 6005.

 

[Decadent_Spectre]

I've tried most things of interest to me, looking to try open baffle but the only thing holding me back is SPL. I need 130db speakers. The pure audio project four 15s speaker looks interesting but doing a little calculation it isn't loud enough, last time I went with different speakers but open baffle intrigues me.

 

[jenson]

Hello Jenson, You asked !! ,

Everyone looks for something cheap. How about trying to figure out what is THE best overall approach,....... and emulate that ??

- - - - - - - - - - - - - - - - - - - - - - - - - - - -

Let me say that again please :


Everyone looks for something cheap. How about trying to figure out what is THE best overall approach,....... and emulate that ??


- - - - - - - - - - - - - - - - - - - - - - -- - - - - -

There are audio facts of life,........ try as you may.............. to subvert the truth:



1) There is NO single driver speaker that is the best answer.

2) Amps are a HUGE problem. The power amp can NOT have any form of NFB ( negative feedback ) and be satisfactory. It must be directly coupled, two-stage tube, in design.

3) The best overall result occurs with speakers that are 101 dB sensitivity rated. The simplest speaker that can satisfy is a two way. This speaker HAS to be front-horn loaded, a two way. For 94% of venues, an A7-8 ALTEC with minor mods will be the answer, as the world's best existing compromise. It is that way today after DECADES of real world use !!!! Stands the test of time.

4) The two way high sensitivity speaker needs to have BOTH drivers FRONT HORN, I say FRONT horn loaded. Never rear horn loaded.

BOTH drivers need to be both FRONT HORN AND ALSO COMPRESSION loaded.

You got it right............ finally..... Both Front horn loaded and BOTH compression loaded.

It takes a 15 inch woofer,............ always.

Listen to Greg Timber's "retirement " interview in 2022, where he talks about NEVER mistaking a woman in a huge shopping mall, unseen, but playing a grand piano. You can TELL what it is playing - live or reproduced, immediately !!!!!!!!!!!!!!!!!!!!! Which is live playback VS reproduced playback !!!!!!! ??????? GREAT analogy. That sentence, idea, solidified the whole concept to ME after 70+ years, in 2022.

5) The drivers need to be PROFESSIONAL USE made, not consumer grade made....not good enough.

Three professional drivers will do :

(1) Pre-WW2......... Klangfilm,

(2) Japanese ALE,

(3) or ALTEC, even better yet (3a) GPA. ) Those are THE three Professional Drivers.


NOW you know !!!!




5) The amplifier absolutely must employ a " fast as the music " L.S.E. S. power supply, or it won't EVER EVER cut the mustard.

Have fun,

I am .

Jeff

A7-8 / 825, 515B, 802d, 811b. SE DC 6005.

lesser mortal like us dont either have easy access to these like in ebay USA, or even if we're to commission a build, wouldn't be sure of how true it is to VOTT. Lastly/firstly, amplification.. per my time reading your posts, I get a feel nobody is doing this commercially... How do i get hold of this holy amp... I really wish I could. It sounds surreal by the way you review it.. And it resonates with lot of us..
OB seems simpler.. I'm yet to experience one, the good thing is I know what I like... my jbl 4312s rocked. I know it's gotta be big drivers. I need to get as close to live sound as I can get. OB with it's dipole structure, seems to have that madness built in

 

[drlowmu]

lesser mortal like us dont either have easy access to to these like in USA, or even if we're to commission a build, wouldn't be sure of how true it is to VOTT. Lastly/firstly, amplification.. per my time reading your posts, I get a feel nobody is doing this commercially... How do i get hold of this holy amp... I really wish I could. It sounds surreal by the way you review it.. And it resonates with lot of us..
OB seems simpler.. I'm yet to experience one, the good thing is I know what I like... my jbl 4312s rocked. I know it's gotta be big drivers. I need to get as close to live sound as I can get. OB with it's dipole structure, seems to have that madness built in

If you want something really good in audio, you GET it !!!!!

Buy it ...........or make it ..... if you want it ........ and............ if you have to.

Hari Iyer wanted a Loftin White type amp, and wrote to me in 2020. You should experience the performance of his own amp's build !!!.

Randy, my Kansas City area friend in the Firehouse, built his VOTT ( H-110) circa 1947-1949 clone during Covid from plans published in Russian, all in millimeters, in a French Hi Fi magazine.

Several simple, complete plans for an ALTEC 825 enclosures are readily available on the web. IF you start, please speak to me first and I will try to assist. Only a very little needs to be done differently. The basic 825 design was done right initially by the movie business EEs ...........in the last century.

PROFESSIONAL DRIVERS !!!!!!!!!!

We NEED to have the extreme magnetic power and the design structure of a compression driver, to re-create the dynamics true to live real musical instruments. Struck piano keys, etc. Once you live with just such a professional-use front horn and compression two-way, with it's purpose-designed amplifier, nothing else will satisfy anyone personally. The amp must use a LSES power supply. It is all you will ever seek to hear.

The 2021 HiFiVision Type 6005 stereo amp is giving me the best listening results I am aware of in ALL of audio !!! I already told you, that small symmetrical output tube is THE best sounding FINALS tube I have ever experienced in audio. The best sounding output tube I ever recall hearing in a lifetime of building. I wrote it up extensively, many pages of amplifier development, here on HFV. We all even got to see the best efforts of a pHD who has never even built a tube amp, pay undue and loving attention to my every word.

Dennis Fraker, of Livingston, MONTANA, has similar designed amps available for sale. Some new, some taken in trade. My mentor. He has a company called Serious Stereo, and he is continually building, progressing , can be fully trusted. HE put me up to doing the in-progress 6005 TRIPLE prototype.

Jeff