Baltic birch or MDF

[Ajitsank]

I am contemplating a DIY project http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm . Looking for inputs on the cabinet.
The build states that the cabinet is made of Baltic birch Sheet. Enquiring around I have understand Baltic Birch sheet's are not common. My question is below;

1. What would be the difference if MDF is used
2. The difference Sonically between both material
3. The person I am taking help in building is in Kerala, Somebody has a connect in Cochin who could help me in the purchase of Baltic Birch sheet in Cochin/Thrissur.
4. Any other alternative material for cabinet

Thanks.

 

[hydrovac]

While I will not comment on the variations in resonances, the MDF dust is terrible...
But if the cabinets are adequately braced, can you hear the difference?

Troels emphasizes how important it is to router the rear of the front baffle, which is behind a bass or mid driver.
I believe that routering can go deeper with a Baltic Birch baffle than it can with MDF.

…

 

[Yelamanchili manohar]

I am contemplating a DIY project http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm . Looking for inputs on the cabinet.
The build states that the cabinet is made of Baltic birch Sheet. Enquiring around I have understand Baltic Birch sheet's are not common. My question is below;

1. What would be the difference if MDF is used
2. The difference Sonically between both material
3. The person I am taking help in building is in Kerala, Somebody has a connect in Cochin who could help me in the purchase of Baltic Birch sheet in Cochin/Thrissur.
4. Any other alternative material for cabinet

Thanks.

Happy to see another Hyderabadi embark on a DIY build. Troels speaker designs are really excellent. By the way...which design have you finalised. Most of the SB acoustics driver range is available in India, unless of course you have already sourced the drivers.

As @hydrovac rightly mentioned, if the speaker is going to be heavily braced, there wont be much difference between MDF and Baltic birch. And Troel also recommends using HDF for the front baffle on which the drivers are mounted. Will be happy to keep reading your progress if you can start a thread in the DIY section to keep us all updated with the build. All the very best

 

[nosortf]

Whatever material you choose to use, gluing the joints is a technique most folk don't understand.
USE MINIMAL GLUE IN A SINGLE LINE. DO NOT OVER GLUE OR IT WILL BEHAVE LIKE A GASKET AND WILL NOT BRACE THE PANELS EFFECTIVELY.

MDF is used by most manufacturers as it requires less bracing, however it may not result in a 'musical' result but a more standard result.
Multi layered birch without airgaps are expensive but necessary. Cabinets need correct multiple bracing.
Normal ply can result in a honk in the lower mid and needs bitumen sheets to dampen it. You can hear this honk in pro audio speakers, and they minimize this by having non parallel trapezoid enclosures.
I can guarantee you that you will waste atleast 4 sets of cabinets in testing alone. Please make sure you are financially geared for this experiment.
A lot of information for you to ponder over.

 

[Ajitsank]

Whatever material you choose to use, gluing the joints is a technique most folk don't understand.
USE MINIMAL GLUE IN A SINGLE LINE. DO NOT OVER GLUE OR IT WILL BEHAVE LIKE A GASKET AND WILL NOT BRACE THE PANELS EFFECTIVELY.

MDF is used by most manufacturers as it requires less bracing, however it may not result in a 'musical' result but a more standard result.
Multi layered birch without airgaps are expensive but necessary. Cabinets need correct multiple bracing.
Normal ply can result in a honk in the lower mid and needs bitumen sheets to dampen it. You can hear this honk in pro audio speakers, and they minimize this by having non parallel trapezoid enclosures.
I can guarantee you that you will waste atleast 4 sets of cabinets in testing alone. Please make sure you are financially geared for this experiment.
A lot of information for you to ponder over.

Thanks now that is scary. I am not prepared for that. Would you then take a safe bet and use MDF.

 

[Yelamanchili manohar]

Thanks now that is scary. I am not prepared for that. Would you then take a safe bet and use MDF.

I would say dont experiment too much. Stick with Troels plans for drivers and cabinet dimensions. Troels mentions using MDF instead of baltic birch, so stick to MDF. And only for the front baffle, use HDF. My speakers are MDF completely, and they are the best I've ever heard. So go ahead with your build full steam

 

[Ajitsank]

Happy to see another Hyderabadi embark on a DIY build. Troels speaker designs are really excellent. By the way...which design have you finalised. Most of the SB acoustics driver range is available in India, unless of course you have already sourced the drivers.

As @hydrovac rightly mentioned, if the speaker is going to be heavily braced, there wont be much difference between MDF and Baltic birch. And Troel also recommends using HDF for the front baffle on which the drivers are mounted. Will be happy to keep reading your progress if you can start a thread in the DIY section to keep us all updated with the build. All the very best

Hi Manu, I am looking towards Elipticore A50 passive. But the drivers aren't available in India and very expensive, thus was adviced look at for drivers ,combination of SB Tweeter, FatalPro for mid bass , dome and eminence for woofer.

Again these are all initial thoughts. The second option is to build SB acoustics SBA.10

Please do share your thoughts/opinion.

 

[Yelamanchili manohar]

Hi Manu, I am looking towards Elipticore A50 passive. But the drivers aren't available in India and very expensive, thus was adviced look at for drivers ,combination of SB Tweeter, FatalPro for mid bass , dome and eminence for woofer.

Again these are all initial thoughts. The second option is to build SB acoustics SBA.10

Please do share your thoughts/opinion.

Hi Ajit

The elipticore are top of the food chain drivers .

Apart from Troel's own build which was used by Scanspeak to demonstrate the drivers, I havent seen any commercial offerings so far. But they are the most highly rated drivers out there, alongside the Accuton ceramic drivers.

My Diy speakers use the same tweeter ( SB Satori berrylium ), and mid range driver ( SB satori egyptian papyrus 6.5 inch ) as the SBA-10. The bass driver is different and is a seas prestige 10 incher. We went for a different bass driver as i wanted a transmission line for the bass.

Last time I checked, the SB 10 inch bass driver was not available in India, so something to ponder over. That said, these drivers are tremendous. I wanted a very fat, solid, weighty and emotional mid range and treble. And these drivers deliver just that when placed in a very wide baffle.

I would encourage you to proceed with the utmost confidence. You are on the right path. Commercial speakers which employ there drivers start at Euro 18,000/-. ( Audio solutions vantage B ). Though Fritz uses the Be tweeter in his top carrera with revelator mid bass, even kaiser acoustics use them.

When I was contemplating a SBA-10 build, below was a finish option I liked, please feel free to copy it if you like. You can always buy me a beer later in Hyderabad





By the way, if you have not finalised the build with a builder, then there are others as well who can undertake it. I will PM you the details if you need. But lets keep the rest on the forum, so that others can read openly and benefit too

And as I said....please go full speed, you are on the right path to nirvana

 

[aeroash]

I am contemplating a DIY project http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm . Looking for inputs on the cabinet.

The build states that the cabinet is made of Baltic birch Sheet. Enquiring around I have understand Baltic Birch sheet's are not common. My question is below;

1. What would be the difference if MDF is used
2. The difference Sonically between both material
3. The person I am taking help in building is in Kerala, Somebody has a connect in Cochin who could help me in the purchase of Baltic Birch sheet in Cochin/Thrissur.
4. Any other alternative material for cabinet

Thanks.

You can use marine plywood as a replacement.
Screws do not tighten enough or may lose threading in MDF. One way to mitigate this is to use D-nuts to mount drivers, this system also comes with its own set of problems. Follow Troels bracing and damping scheme and you should be good with marine plywood.

 

[Ajitsank]

Hi Ajit

The elipticore are top of the food chain drivers .

Apart from Troel's own build which was used by Scanspeak to demonstrate the drivers, I havent seen any commercial offerings so far. But they are the most highly rated drivers out there, alongside the Accuton ceramic drivers.

My Diy speakers use the same tweeter ( SB Satori berrylium ), and mid range driver ( SB satori egyptian papyrus 6.5 inch ) as the SBA-10. The bass driver is different and is a seas prestige 10 incher. We went for a different bass driver as i wanted a transmission line for the bass.

Last time I checked, the SB 10 inch bass driver was not available in India, so something to ponder over. That said, these drivers are tremendous. I wanted a very fat, solid, weighty and emotional mid range and treble. And these drivers deliver just that when placed in a very wide baffle.

I would encourage you to proceed with the utmost confidence. You are on the right path. Commercial speakers which employ there drivers start at Euro 18,000/-. ( Audio solutions vantage B ). Though Fritz uses the Be tweeter in his top carrera with revelator mid bass, even kaiser acoustics use them.

When I was contemplating a SBA-10 build, below was a finish option I liked, please feel free to copy it if you like. You can always buy me a beer later in Hyderabad

View attachment 82695

View attachment 82696

By the way, if you have not finalised the build with a builder, then there are others as well who can undertake it. I will PM you the details if you need. But lets keep the rest on the forum, so that others can read openly and benefit too

And as I said....please go full speed, you are on the right path to nirvana

Could you please clarify below;

Though my preference in to build Ellipticor-A50-II, Would it be Ok to use Combination of other locally available drivers. Obviously it will then depart from Troels Gravesen build. It will then require driver specific Crossover etc. Other than look and size of cabinet nothing will remain same.

After your inputs I am more inclined towards SBA10, however would like know your thoughts on building Ellipticor with locally available drivers.

 

[Yelamanchili manohar]

Could you please clarify below;

Though my preference in to build Ellipticor-A50-II, Would it be Ok to use Combination of other locally available drivers. Obviously it will then depart from Troels Gravesen build. It will then require driver specific Crossover etc. Other than look and size of cabinet nothing will remain same.

After your inputs I am more inclined towards SBA10, however would like know your thoughts on building Ellipticor with locally available drivers.

Hi Ajit

Troels designs are very very specific to the exact drivers he uses. The design consists of the drivers, cabinet dimensions and crossover as a combined unit. Any alteration of one, will degrade the whole design and performance. If you want to build any of his designs, you have to buy the exact same drivers from outside or from his site. Then buy his crossovers and get the exact cabinet built. Any deviations in the above, and one is on his own.

We cannot mix and match drivers and crossovers in the above or in any other design for that matter. We either go fully with Troel or are on our own.

Unless you have a lot of speaker building experience under your belt, stick to published designs online. Not easy to build a speaker from scratch without a lot of knowledge and experience to back it up. So first see what drivers you can procure. Then check for online build plans using these drivers. Seek help on the forum as and when required.

 

[Ajitsank]

Hi Ajit

Troels designs are very very specific to the exact drivers he uses. The design consists of the drivers, cabinet dimensions and crossover as a combined unit. Any alteration of one, will degrade the whole design and performance. If you want to build any of his designs, you have to buy the exact same drivers from outside or from his site. Then buy his crossovers and get the exact cabinet built. Any deviations in the above, and one is on his own.

We cannot mix and match drivers and crossovers in the above or in any other design for that matter. We either go fully with Troel or are on our own.

Unless you have a lot of speaker building experience under your belt, stick to published designs online. Not easy to build a speaker from scratch without a lot of knowledge and experience to back it up. So first see what drivers you can procure. Then check for online build plans using these drivers. Seek help on the forum as and when required.

Thanks Manu. Will do as told.

 

[Yelamanchili manohar]

Thanks Manu. Will do as told.

Just thought I'd add that SB acoustics have their won recommended speaker designs here :

SB Acoustics Kits - Sbacoustics

sbacoustics.com

And you can source their drivers here :

Audiofy | One Stop for SB Acoustics Speakers in INDIA

Audiofy™ is India's Official Distributor for SB Acoustics Speakers Drivers & Air Core Coils Manufacturer Established in Hyderabad, Telangana.

audiofy.in

 

[Passive_audio_enthusiast]

Whatever material you choose to use, gluing the joints is a technique most folk don't understand.
USE MINIMAL GLUE IN A SINGLE LINE. DO NOT OVER GLUE OR IT WILL BEHAVE LIKE A GASKET AND WILL NOT BRACE THE PANELS EFFECTIVELY.

MDF is used by most manufacturers as it requires less bracing, however it may not result in a 'musical' result but a more standard result.
Multi layered birch without airgaps are expensive but necessary. Cabinets need correct multiple bracing.
Normal ply can result in a honk in the lower mid and needs bitumen sheets to dampen it. You can hear this honk in pro audio speakers, and they minimize this by having non parallel trapezoid enclosures.
I can guarantee you that you will waste atleast 4 sets of cabinets in testing alone. Please make sure you are financially geared for this experiment.
A lot of information for you to ponder over.

Do you have examples to how the glue should be? I never gave thought to it before.

 

[nosortf]

Hi Manu, I am looking towards Elipticore A50 passive. But the drivers aren't available in India and very expensive, thus was adviced look at for drivers ,combination of SB Tweeter, FatalPro for mid bass , dome and eminence for woofer.

Again these are all initial thoughts. The second option is to build SB acoustics SBA.10

Please do share your thoughts/opinion.

The 15 inch ellipticor in passive mode will be down by 3db at 53Hz. Not very low for a big driver.

 

[nosortf]

Do you have examples to how the glue should be? I never gave thought to it before.

Firstly to achieve best results the cabinet has to be CNC cut for exact jointing to take place. The fit has to be extremely tight without glue, and the glue itself is only a chemical binding agent. Hence a single line in the groove and single lines on top and lower sections of brace going into the groove. This will chemically bond the two pieces of wood without behaving like a loose gasket layer, which a heavy coating of glue will do, damaging the intended results.

 

[sbg]

Do apply ample amount of wood glue , what matters most is how good/optimum your clamp pressure are to press the 2 sheets in what ever the orientation. Anything that is in excess will seep out during clamping process.
..Just my experiences after multiple woodworking builds.
Note : in one of the builds, the box(with braces, no nails) had fallen off the table (3 feet) - no damage!

 

[nosortf]

For assured results you will have to have CNC cut panels and bracing. Best to get a DIY kit with precut flat pack panels. This way you are ensured of avoiding mistakes.
I prefer using veneered 15 mm particle board for enclosures, if CNC is not possible. With self dampening particle board enclosures you can use drivers with a higher QTS and get a warm vintage low frequency.

 

[keith_correa]

I prefer using veneered 15 mm particle board for enclosures, if CNC is not possible.

How does 15mm particle board make up for not having CNC cut panels?

With self dampening particle board enclosures you can use drivers with a higher QTS and get a warm vintage low frequency.

What's the relationship between driver Qts and the enclosure material? Also, while I'm at it - what is warm "vintage" low frequency???

 

[nosortf]

Particle board enclosures do not require extensive bracing, a simple BTC vertical and horizontal member will suffice, no complex CNC required. The material is quite absorbent by itself and hence works with drivers with a higher QTS.

Warm vintage low frequency = QTC between 0.9 - 1.1 in a sealed enclosure, classic floor standing Technics out of the 70s, that looks shit on specs but loved by most audiophiles.