Open Baffle Speakers Advise Please

[msagar]

Hello @Hari Iyer and @yogibear and FMs

I have acquired:
2 Tangband 1808 Full range drivers
4 SB Audience Bianco 150B350 Open Baffle drivers
1 Greenply 25mm 4'x8' plywood sheet
Essential hardware

Professional carpenter on hand

Should I go for Woofer - Full range - Woofer design (Pure Audio Project)
or Full range - Woofer - Woofer design (Spatial Audio Labs)

With WFW design tweeter level is approx. 24"-26" and with FWW design tweeter level is approx. 46"-48"
I would prefer tweeter at ear level

For crossover I am considering minidsp 2x4HD

Please Advise

Thank you.

 

[Yelamanchili manohar]

Hello @Hari Iyer and @yogibear and FMs

I have acquired:
2 Tangband 1808 Full range drivers
4 SB Audience Bianco 150B350 Open Baffle drivers
1 Greenply 25mm 4'x8' plywood sheet
Essential hardware

Professional carpenter on hand

Should I go for Woofer - Full range - Woofer design (Pure Audio Project)
or Full range - Woofer - Woofer design (Spatial Audio Labs)

With WFW design tweeter level is approx. 24"-26" and with FWW design tweeter level is approx. 46"-48"
I would prefer tweeter at ear level

For crossover I am considering minidsp 2x4HD

Please Advise

Thank you.

Small world and what a coincidence, Iam pretty much planning the same thing

I don't have your full ranger, but have the same bass drivers. I was planning on going a bit overboard with WWTMWW combo. My room is small, so I dont actually need that many drivers per side. But since I have them at hand, thought why not string them out to dry and see

In your case, TWW will be better, as you will get the tweeter slightly above seated ear height. Making it WTW will place tweeter at 24 inches above ground, which is not ideal. And the singers will sound like they are singing from their graves

( Actually from what I've read, more woofers, will mean less excursion, and more effeciency and better dynamics. And with lesser overall cone movement, it will give us more EQ range, so that we don't hit that max 11 mm excursion limit. )

I did some research on those PAP speakers. Actually measured the sizes with a ruler, and scaled it to known measurements of the baffle width of 54 cms. Not the most ethical thing to do...I know

The baffle sizes are 54 (w) x 41.5(h) cms for the bass baffles. And for the center baffle with full ranger it will be a 54 (w) x 30.5 (h) cms. Spacing between each baffle is 1 cm. The material is 3/4" HDF.

@yogibear knows way better than me between open baffle and U-baffle. Iam aware that he is not in favour of using H-frames, and has been a vocal proponent of U-baffles.

But if you go full on open baffle, then as done by PAP, mount the drivers on their individual baffles. And mount the baffles on a common stand with some kind of isolation between the baffle and the common stand, like rubber washers etc...to prevent the bass vibrations from reaching and skewing the full ranger's output.

All the best...and please keep this thread updated with your progress

Edit : Saw you are from hyderabad too. There are CNC wood shops in the KPHB area, that will give you full fabricated baffles, if you can sketch it up in CAD or on sketchup software ( free ). I think i only paid 4k or so a few years back, for a full on ripole sub build, including MDF, which needed more wood than this. So, in the end, getting the baffles CNC'ed might be cheaper in the end. Though you still have to figure out the stand to mount these baffles on

 

[Vineethkumar01]

IMO, anybody venturing into the design & build of open baffle speakers should have read this and the links mentioned therein.
Especially, the classic open baffle vs U frame vs H frame part.

Open baffle speaker pitfalls

Open baffle (OB) speakers seem to be becoming more and more popular at the moment. The possible advantages of an OB speaker do not need to be listed here, they can be found on every manufacturer's website or audio forums. When using or purchasing U-frame or V-frame (and to some degree H-frame)...

www.audiosciencereview.com

 

[Hari Iyer]

Very recently I rebuilt my OB speakers and discovered that they are not very easy to engineer as it may obviously look. I have been working now almost for 3 weeks and would have finally achieved my desired tonality.

I have used a 12" Alnico, low compliance woofer and a 12" Ahija, reconed, low compliance woofer in a push-pull H- frame baffle. The combined impedance is 2.67 ohms. I used a passive 2nd order LR filter at 230Hz on this.

I am using a Sachenwerk field coil midrange driver on a narrow OB and they are again having a 2nd order LR @ 1600Hz. The low end is having a natural acoustic rolloff which seamlessly integrate with the H- frame.

I am using a JBL Selenium CD with a Dayton Audio waveguide on the same OB frame as the midrange. These are again crossed @ 1600Hz.

With these I was able tp gey excellent mids and highs, but the lows suffered z lot. I then went ahead and implemented a passive low pass shelving in my preamplifier output @ -18dB from 120hz till 900hz. This bought back reasonable bass from my setup, but the rolloff begin was from 70Hz and @ 24dB/ octave. Clearly the lowend thump/ punch was missing. Hence I needed to add my additional H- frame subwoofer which is rolled off at 70Hz. This bridged the gap and now sound seamless in the entire bandwidth. Someone said that - "unless you get your bass right, people are not going to like your setup". And I followed the above statement and got my bass right.

Also would like to mention that my 3+3 watts tube amplifier were not able to drive the primary H-frame easily and hence had to add another subwoofer. If you are using a higher wattage amplifier YMMV.

Unless you have the means, budget, time to measure, listen and experiment getting the OB design correct in the first attempt is easier said than done. Be ready for countless fine tuning that you may require on your journey.

This is how my setup looks.

 

[devstation18]

Hello @Hari Iyer and @yogibear and FMs

I have acquired:
2 Tangband 1808 Full range drivers
4 SB Audience Bianco 150B350 Open Baffle drivers
1 Greenply 25mm 4'x8' plywood sheet
Essential hardware

Professional carpenter on hand

Should I go for Woofer - Full range - Woofer design (Pure Audio Project)
or Full range - Woofer - Woofer design (Spatial Audio Labs)

With WFW design tweeter level is approx. 24"-26" and with FWW design tweeter level is approx. 46"-48"
I would prefer tweeter at ear level

For crossover I am considering minidsp 2x4HD

Please Advise

Thank you.

Hello @Hari Iyer and @yogibear and FMs

I have acquired:
2 Tangband 1808 Full range drivers
4 SB Audience Bianco 150B350 Open Baffle drivers
1 Greenply 25mm 4'x8' plywood sheet
Essential hardware

Professional carpenter on hand

Should I go for Woofer - Full range - Woofer design (Pure Audio Project)
or Full range - Woofer - Woofer design (Spatial Audio Labs)

With WFW design tweeter level is approx. 24"-26" and with FWW design tweeter level is approx. 46"-48"
I would prefer tweeter at ear level

For crossover I am considering minidsp 2x4HD

Please Advise

Thank you.

Grt combo even I am planning a much more simpler setup with Eminence Alpha 15 for low end and Tang Band W1808 Full Range , but how did u source the Tang Bands 1808 , understand they are out of stock and the ones in parts express are asking exorbitant price

 

[Vineethkumar01]

@Hari Iyer
Just a suggestion regarding the horn protruding from the baffle (or it looks like that in the pic).
In general, it is not good to have drivers protruding out from a baffle (the extent of the issue might depend on the said driver's passband and crossover point though). Take a look here for an example:

Acoustic Horn Design – The Easy Way (Ath4)

I'd be perhaps more interested in e.g. HF146 (1.4"). With a ring one could get to a ~1" performance (which I still believe is good enough as it is)... That's more valuable than what I proposed wrt reducing a 1" compression driver, at least to me. Does anyone know what the inside diameter of the...

www.diyaudio.com

 

[Hari Iyer]

@Hari Iyer
Just a suggestion regarding the horn protruding from the baffle (or it looks like that in the pic).
In general, it is not good to have drivers protruding out from a baffle (the extent of the issue might depend on the said driver's passband and crossover point though). Take a look here for an example:

Acoustic Horn Design – The Easy Way (Ath4)

I'd be perhaps more interested in e.g. HF146 (1.4"). With a ring one could get to a ~1" performance (which I still believe is good enough as it is)... That's more valuable than what I proposed wrt reducing a 1" compression driver, at least to me. Does anyone know what the inside diameter of the...

www.diyaudio.com

The WG is protruding for time delay else the HF gets delayed w.r.t midrange. Time alignment allowed smooth step response and tighter integration between mids and highs. Mine is a passive XO setup with no DSP.

 

[msagar]

Wow ! What a sexy start on OBs !!! (Moderators, I apologize for the term but couldn’t help it)

Who advised you on these drivers ?

How big is your room ? Do you have friendly neighbors ?

Go FWW but be wary of woofer vibrations muddling the FR. U frame on woofers would be most desirable.

MiniDSP on these will teach you a lot. Later must put that learning to go passive on the whole setup. Would be a high dB setup that I would love to ride through a tube amp !

Thank you for your suggestions.
Researching audio forums including HFV and availability of drivers in India led me to zero in on drivers.
I live in an independent house and room size is approx. 40'x30'x10'.
I am planning to drive OBs with 10w/ch SOULNOTE monitor amplifier.
Is it possible to get a good passive crossover for open baffles in India?

 

[msagar]

Small world and what a coincidence, Iam pretty much planning the same thing

I don't have your full ranger, but have the same bass drivers. I was planning on going a bit overboard with WWTMWW combo. My room is small, so I dont actually need that many drivers per side. But since I have them at hand, thought why not string them out to dry and see

In your case, TWW will be better, as you will get the tweeter slightly above seated ear height. Making it WTW will place tweeter at 24 inches above ground, which is not ideal. And the singers will sound like they are singing from their graves

( Actually from what I've read, more woofers, will mean less excursion, and more effeciency and better dynamics. And with lesser overall cone movement, it will give us more EQ range, so that we don't hit that max 11 mm excursion limit. )

I did some research on those PAP speakers. Actually measured the sizes with a ruler, and scaled it to known measurements of the baffle width of 54 cms. Not the most ethical thing to do...I know

The baffle sizes are 54 (w) x 41.5(h) cms for the bass baffles. And for the center baffle with full ranger it will be a 54 (w) x 30.5 (h) cms. Spacing between each baffle is 1 cm. The material is 3/4" HDF.

@yogibear knows way better than me between open baffle and U-baffle. Iam aware that he is not in favour of using H-frames, and has been a vocal proponent of U-baffles.

But if you go full on open baffle, then as done by PAP, mount the drivers on their individual baffles. And mount the baffles on a common stand with some kind of isolation between the baffle and the common stand, like rubber washers etc...to prevent the bass vibrations from reaching and skewing the full ranger's output.

All the best...and please keep this thread updated with your progress

Edit : Saw you are from hyderabad too. There are CNC wood shops in the KPHB area, that will give you full fabricated baffles, if you can sketch it up in CAD or on sketchup software ( free ). I think i only paid 4k or so a few years back, for a full on ripole sub build, including MDF, which needed more wood than this. So, in the end, getting the baffles CNC'ed might be cheaper in the end. Though you still have to figure out the stand to mount these baffles on

Thank you for sharing your thoughts.
As suggested I will keep this thread updated.

 

[msagar]

IMO, anybody venturing into the design & build of open baffle speakers should have read this and the links mentioned therein.
Especially, the classic open baffle vs U frame vs H frame part.

Open baffle speaker pitfalls

Open baffle (OB) speakers seem to be becoming more and more popular at the moment. The possible advantages of an OB speaker do not need to be listed here, they can be found on every manufacturer's website or audio forums. When using or purchasing U-frame or V-frame (and to some degree H-frame)...

www.audiosciencereview.com

Thank you Vineeth for sharing the link.

 

[msagar]

Grt combo even I am planning a much more simpler setup with Eminence Alpha 15 for low end and Tang Band W1808 Full Range , but how did u source the Tang Bands 1808 , understand they are out of stock and the ones in parts express are asking exorbitant price

I bought Tang Bands from a member on this forum. He bought them from http://diyaudiocart.com.

 

[msagar]

Very recently I rebuilt my OB speakers and discovered that they are not very easy to engineer as it may obviously look. I have been working now almost for 3 weeks and would have finally achieved my desired tonality.

I have used a 12" Alnico, low compliance woofer and a 12" Ahija, reconed, low compliance woofer in a push-pull H- frame baffle. The combined impedance is 2.67 ohms. I used a passive 2nd order LR filter at 230Hz on this.

I am using a Sachenwerk field coil midrange driver on a narrow OB and they are again having a 2nd order LR @ 1600Hz. The low end is having a natural acoustic rolloff which seamlessly integrate with the H- frame.

I am using a JBL Selenium CD with a Dayton Audio waveguide on the same OB frame as the midrange. These are again crossed @ 1600Hz.

With these I was able tp gey excellent mids and highs, but the lows suffered z lot. I then went ahead and implemented a passive low pass shelving in my preamplifier output @ -18dB from 120hz till 900hz. This bought back reasonable bass from my setup, but the rolloff begin was from 70Hz and @ 24dB/ octave. Clearly the lowend thump/ punch was missing. Hence I needed to add my additional H- frame subwoofer which is rolled off at 70Hz. This bridged the gap and now sound seamless in the entire bandwidth. Someone said that - "unless you get your bass right, people are not going to like your setup". And I followed the above statement and got my bass right.

Also would like to mention that my 3+3 watts tube amplifier were not able to drive the primary H-frame easily and hence had to add another subwoofer. If you are using a higher wattage amplifier YMMV.

Unless you have the means, budget, time to measure, listen and experiment getting the OB design correct in the first attempt is easier said than done. Be ready for countless fine tuning that you may require on your journey.

This is how my setup looks.

Thank you for sharing your experience with OB design and building process.

 

[Vineethkumar01]

The WG is protruding for time delay else the HF gets delayed w.r.t midrange. Time alignment allowed smooth step response and tighter integration between mids and highs. Mine is a passive XO setup with no DSP.

I guess it is up to design choices and personal preferences, then.
My personal approach is to shape the frequency response as required with as minimal anomalies as possible and then correct the phase using DSP to get the step response clean enough.

 

[Hari Iyer]

I guess it is up to design choices and personal preferences, then.
My personal approach is to shape the frequency response as required with as minimal anomalies as possible and then correct the phase using DSP to get the step response clean enough.

I am using analogue sources too - TT, TD. If your source is digitial and play from your laptop then you can easily use MiniDSP & PE with them. I out of my own preference have avoided too much EQ to avoid coloration. I have tried PE using REW and with standard house curves suggested. But somehow my ears don't accept the equaliziatfrom REW though they measure flat at my sweet listening position. Maybe I am doing something wrong. I have never listened tova MINI DSP based setup till now elsewhere so won't be able to comment on that.

 

[Yelamanchili manohar]

IMO, anybody venturing into the design & build of open baffle speakers should have read this and the links mentioned therein.
Especially, the classic open baffle vs U frame vs H frame part.

Open baffle speaker pitfalls

Open baffle (OB) speakers seem to be becoming more and more popular at the moment. The possible advantages of an OB speaker do not need to be listed here, they can be found on every manufacturer's website or audio forums. When using or purchasing U-frame or V-frame (and to some degree H-frame)...

www.audiosciencereview.com

I've read this in the recent past. And i quickly lost interest, as the author claiming his knowledge to be limited on OB designs, went onto criticize some OB speakers that actually managed to sell. Would have been nice if he left any useful tips at actually building a OB speaker, as there are no reliable simulators for the same at the moment. And it seems very much in the domian of try it and see.

I found the Linkwitz site more useful, as he shares some basic calculations for U & H-frame baffles, which I found useful.

 

[Yelamanchili manohar]

Linkwitz is best site and MJK papers on H frame / U frame are most helpful.

Basta software helps you make comparison of different baffle widths, different drivers and their placement on baffle wrt their roll off at low end.

Thanks a ton for sharing about the basta software

Will definitely check if out. Thanks

 

[Vineethkumar01]

I've read this in the recent past. And i quickly lost interest, as the author claiming his knowledge to be limited on OB designs, went onto criticize some OB speakers that actually managed to sell.

cntrl is a well respected member on that forum. His area of expertise may not be open baffle-concept based designs. But that in no way affects his skill in inferring trends in the radiation behaviour of any particular concept, be it monopole, dipole or any other radiation pattern. Also the basics oo open baffle design concepts are available in places you mentioned like linkwitz's site and other places. Here are few more links about the same
1) John K's site or whatever is left of it

Tech

A list of technical articles on the web site

musicanddesign.speakerdesign.net

2) http://www.dipolplus.de/thema6.html

3) Charlie Laub's thread on diyaudio

In Pursuit of a 20-20k Dipole Loudspeaker

I thought I would kick off 2019 with this thread about dipole loudspeaker design and construction. Specifically, how to create a loudspeaker having a dipole radiation pattern across as wide a frequency range as possible, when it might make sense to abandon this goal in favor of some other...

www.diyaudio.com

There is no magic in open baffle/dipole speaker design. At its core, it is about accepting a certain compromise w.r.t radiation behaviour & resulting room interaction & a certain sound character. However, as cntrl has pointed out in his radiation behaviour analysis of certain speakers, some are just faulty designs irrespective of whether they managed to sell or not. Deviating from dipole radiation behaviour, as a design compromise, or unknowingly is bound to affect the overall sound character. Whether some one likes it or not is a separate issue. Anyway, by now, we all know that the best-designed speaker is not always the one that sells more, for whatever reason, especially in hifi audio.

Hence, IMO, the focus of a sensible DIYer should be to understand the pitfalls that cntrl has pointed out and not repeat the same if one's objective is to learn and do a proper dipole radiation pattern based speaker design

Would have been nice if he left any useful tips at actually building a OB speaker, as there are no reliable simulators for the same at the moment. And it seems very much in the domian of try it and see.

It is not at all a cut and try design approach for open baffle speaker especially when VituixCAD is around. BASTA has sort of become outdated. VituixCAD can do all that it does and even more.
For example, here is a quick sim of diffraction behaviour of an open baffle speaker in VituixCAD. All kinds of 2D shapes for baffle & all practical sizes of drivers can be simulated like below


Even more importantly, if one aims to apply this to a real driver response, one can export the measured/traced half space response and create full Spinorama & radiation pattern. Here is an example of the above diffraction & radiation behviour applied to an omni-radiating source (by default)

'


VituixCAD screen shot

 

[Hari Iyer]

Linkwitz is best site and MJK papers on H frame / U frame are most helpful.

Basta software helps you make comparison of different baffle widths, different drivers and their placement on baffle wrt their roll off at low end.

Surprisingly rhe Basta simulation grossly disagree with my actual measurements though.

 

[Yelamanchili manohar]

cntrl is a well respected member on that forum. His area of expertise may not be open baffle-concept based designs. But that in no way affects his skill in inferring trends in the radiation behaviour of any particular concept, be it monopole, dipole or any other radiation pattern. Also the basics oo open baffle design concepts are available in places you mentioned like linkwitz's site and other places. Here are few more links about the same
1) John K's site or whatever is left of it

Tech

A list of technical articles on the web site

musicanddesign.speakerdesign.net

2) http://www.dipolplus.de/thema6.html

3) Charlie Laub's thread on diyaudio

In Pursuit of a 20-20k Dipole Loudspeaker

I thought I would kick off 2019 with this thread about dipole loudspeaker design and construction. Specifically, how to create a loudspeaker having a dipole radiation pattern across as wide a frequency range as possible, when it might make sense to abandon this goal in favor of some other...

www.diyaudio.com

There is no magic in open baffle/dipole speaker design. At its core, it is about accepting a certain compromise w.r.t radiation behaviour & resulting room interaction & a certain sound character. However, as cntrl has pointed out in his radiation behaviour analysis of certain speakers, some are just faulty designs irrespective of whether they managed to sell or not. Deviating from dipole radiation behaviour, as a design compromise, or unknowingly is bound to affect the overall sound character. Whether some one likes it or not is a separate issue. Anyway, by now, we all know that the best-designed speaker is not always the one that sells more, for whatever reason, especially in hifi audio.

Hence, IMO, the focus of a sensible DIYer should be to understand the pitfalls that cntrl has pointed out and not repeat the same if one's objective is to learn and do a proper dipole radiation pattern based speaker design


It is not at all a cut and try design approach for open baffle speaker especially when VituixCAD is around. BASTA has sort of become outdated. VituixCAD can do all that it does and even more.
For example, here is a quick sim of diffraction behaviour of an open baffle speaker in VituixCAD. All kinds of 2D shapes for baffle & all practical sizes of drivers can be simulated like below
View attachment 80404

Even more importantly, if one aims to apply this to a real driver response, one can export the measured/traced half space response and create full Spinorama & radiation pattern. Here is an example of the above diffraction & radiation behviour applied to an omni-radiating source (by default)
View attachment 80405
'View attachment 80406
View attachment 80407

VituixCAD screen shot
View attachment 80408

Thanks for taking the time to share that. I stand corrected then

 

[Yelamanchili manohar]

Okay a very honest question from me. This is make or break for me.

Having spent quite a bit of time on the DIY threads on the net. I quickly realize that using these design tools to get a scentifically correct measuring speaker is beyond my skill level. And apart from some basic simulation as to acheiveable frequency range, I dont think i can get to the dispersion characteristics etc.

Now I understand that the goal of designing a sceintifically good speaker is to perform optimally in all rooms. But since anything I build will be solely used in my room, will it suffice if I place the frankenstein in the room, at my usual speaker position, and then get the frequency and time coherence correct at my listening position. I guess this will anyways sum up the speaker output, room interaction, dispersion everything. And I only need to get this right at one position in one room. Which is my listening position in my room. Am I correct in assuming this

If that is doable with active dsp, then I can give it a fair shot. Otherwise, I might better utilise my time designing a rocket to reach the sun