Open Baffles

[John]

Jerry asked could we start a thread on open baffles I thought perhaps I start this off, but hope others here who have more experience or used a different approach can write how they went about it.
First of all they are not for everyone, they can be quite large and perhaps not everyone will love the sound. So best if you can hear some before you decide to take this approach.
You can buy open Baffles already built some manufactures who do this some of this do DIY kits also
Jamo http://www.6moons.com/audioreviews/jamo/909.html
Emerald Pyshics http://www.6moons.com/industryfeatures/emeraldphysics/emerald.html
Bastanis Quite a few people have built this here but you can also buy them pre built http://www.bastanis.com/index_e.html
Hawthornes http://www.hawthorneaudio.com/ Mostly DIY but they can build you a pair to your own design Darrell is really helpful
Linkwiz Lab Can build or DIY http://www.linkwitzlab.com/builtown.htm
I write some more thoughts latter

[Mark Grant]

Great idea, I was also going to start a thread about open baffles to find some infrmation so this will be great.

I do like a bit if DIY :)

Any pictures would be helpful, particularly interested in the more rounded designs that John had as his avatar picture recently.

[Clive]

Here are some pics of my Bastanis. Since the pics were taken the main 12" drivers wideband (100Hz - 11kHz) have been replaced with the latest "Chrystal" versions, this gives a richer sound similar to drivers with AlNiCo magnets. Oh yes, Mark Grant i/cs are also my system now but not in these older pics.....

These OBs are around 100db sensitivity, they have 18" bass drivers in a "non-symmetical W-frame" cabinet - they are dipoles as the cabinets are open front and back. The tweeters are also dipoles. I use solidstate amps on the basses with DSP to correct room modes - my room is square with a bay at one end and a low ceiling - none of this is ideal hence the DSP but it works pretty well.

http://i43.photobucket.com/albums/e359/cmeakins/1003200007.jpg

http://i43.photobucket.com/albums/e359/cmeakins/1003200010.jpg

http://i43.photobucket.com/albums/e359/cmeakins/1003200013.jpg

http://i43.photobucket.com/albums/e359/cmeakins/1003200015.jpg

[John]

My design is based on Clive's But I use 40mm MDF In my experience bafflle thickness makes a difference I also have a mounting collar that further isolates the driver from the baffle I also have a complete open back for bass drivers, Clive is a different approach to mine. I add pictures latter
The other major difference between Clive and mine is the main driver in mine are 15" duel concentric. Clive system is more sensitive than mine but 95db is still not bad. Both of us use active bass systems but I hope Steve (SPS) be along to explain how he uses passive bass.

[Gazjam]

Heard Ali T's OB's over at mine recently...amazing sound.
Loved them.

[Clive]

We must also mention the SABA drivers available from ebay in Germany, these are only a little over 100 Euros for a pair of mids and tweeters with AlNiCo magnets. They need to be mated with a bass driver. Personally....I quite like them but the sound can be a little "small" for me. The mid driver is simply too small IMO, big drivers in OBs work really well - bear in mind there's no cabinet to provide resistance for the cone so bigger drivers work. In a small room the SABAs could be magic.

http://www.lampizator.eu/SPEAKERS/PROJECTS/P17/Endorphine%20from%20Kingston%20Kitchen.html

[aquapiranha]

I have heard a pair of OB's with SABA drivers belonging to Dave Hewitt and I thought they were very good. One point to note is that while most OB's have a couple of big woofers, the bass they produce is more 'realistic' than closed designs if that makes any sense? On the plus side, they are easy to build, like the one's I built which Ali now uses. Also, I used them with an active crossover which I think gives a greater degree of flexibility with regard to tweaking. YMMV

[John]

Yes the SABA's are really nice I heard only one pair, just a bit to shouty on distorted guitars for me, but on Acoustic music really good. Lots of detail and speed. A really cheap way to get into OBs.

[Clive]

It's worth mentioning that OBs have many, many variations, just as boxed speakers do. The Jamos for instance are not the simple load of the SABAs, Hawthornes or Bastanis. These "simple" load OBs tend to be great matches for simple amps, often valve (SE and PP). SE can really shine with them. Simplicity of xover is a factor here. OBs also mate well with chip amps.

I'm with John on the SABAs re acoustic material.

[aquapiranha]

I was using the OB's with a 4 channel Tripath amp from Sure electronics, via a Rane AC22B analogue active X-over, so I agree with you Clive, although the Tripath is not a 'chip' amp as such.

[Clive]

I was using the OB's with a 4 channel Tripath amp from Sure electronics, via a Rane AC22B analogue active X-over, so I agree with you Clive, although the Tripath is not a 'chip' amp as such.
I was trying not say "digital" amps as I hate the term, maybe say Class T. Digital means binary to me....yes, I've heard Tripath amps on my speakers. Very good indeed.

[John]

A lot of people are using Spud amps to power OB's. I not really heard any and would worry about a Spud amp ablity to rock on my speakers, but according to reports a very clean sound at a great price.

[John]

T amps also work well on mine so its clear to see this is a very cost effective way into great sounds

[Rare Bird]

http://i43.photobucket.com/albums/e359/cmeakins/1003200007.jpg




Thats a nice Rug Clive where did you get that from if yer don't mind me askin'?

[Clive]

Thats a nice Rug Clive where did you get that from if yer don't mind me askin'?
:) unusually we bought the rug in the UK, it's from Pakistan. Other rugs we've brought at source.

[SPS]

We must also mention the SABA drivers available from ebay in Germany, these are only a little over 100 Euros for a pair of mids and tweeters with AlNiCo magnets. They need to be mated with a bass driver. Personally....I quite like them but the sound can be a little "small" for me. The mid driver is simply too small IMO, big drivers in OBs work really well - bear in mind there's no cabinet to provide resistance for the cone so bigger drivers work. In a small room the SABAs could be magic.

http://www.lampizator.eu/SPEAKERS/PROJECTS/P17/Endorphine%20from%20Kingston%20Kitchen.html

one of the lads over on audio-talk has some that he brought along to our last meet, they sounded very good, they where tried on a few amps and they high lighted the amplifier differences well, at the end of the day we tried them on my set up, they sounded very sweet.

It inspired my to try some telefunken drivers i have that looked the same, the 3" driver sounded fine, but needed a better bottom end driver to match the sound qualty. i tried a few different ones and got a good sound

[SPS]

Great idea, I was also going to start a thread about open baffles to find some infrmation so this will be great.

I do like a bit if DIY :)

Any pictures would be helpful, particularly interested in the more rounded designs that John had as his avatar picture recently.

come and have a listen to mine if your interested..

i only live a few miles down the road..

[John]

Steve in the past you mentioned you manage to use valve amp to power you bass If possible can you explain how you achieved this

[SPS]

Steve in the past you mentioned you manage to use valve amp to power you bass If possible can you explain how you achieved this

by going the opposite direction to what most people think is the right way..

when i put together an open baffle speaker, my first thought is matching the efficiencies of the drivers

you then have a head start,

its not rocket science really, but the higher efficiency bass drivers roll off more in the bass, but have a shallower slope than normal drivers,
looking at new drivers they all have response graphs, its about picking drivers that get close to what you want, then implementing them to get the most out of them... a decible or two through carefull design can make all the difference, then a bit of room gain.

in my experence low eff and high eff cone speakers dont really mix, so i'm sorted commited to using single amp. and doing my best to get all the speakers reasonable level, which i've just about managed with the present set up

we are really talking about using quality pa type drivers (not crap)

and blending them together...

not much of an answer...

[John]

Great idea, I was also going to start a thread about open baffles to find some infrmation so this will be great.

I do like a bit if DIY :)

Any pictures would be helpful, particularly interested in the more rounded designs that John had as his avatar picture recently.

Heres some pictures of my speaker build Mark
http://theartofsound.net/forum/showthread.php?t=6143&highlight=open+baffles
I would do it slightly different if I was to do it again. the bit I would do differently is the rear collar I would sit the drivers in the collar so that the drivers have a bit more isolation from the baffles. Darrel at Hawthrone reckons having some kind of seperate mounting plates helps improves performance.
I think any Open baffle design is a DIY person dream because there is room for little tweaks that further improve performance and plenty of help from people who have tried and tested different ideas.
For me having the thicker baffles allowed a lot more detail to come through and I think I get a bit more if I add a brace at the back sometime to increase rigidty

[John]

by going the opposite direction to what most people think is the right way..

when i put together an open baffle speaker, my first thought is matching the efficiencies of the drivers

you then have a head start,

its not rocket science really, but the higher efficiency bass drivers roll off more in the bass, but have a shallower slope than normal drivers,
looking at new drivers they all have response graphs, its about picking drivers that get close to what you want, then implementing them to get the most out of them... a decible or two through carefull design can make all the difference, then a bit of room gain.

in my experence low eff and high eff cone speakers dont really mix, so i'm sorted commited to using single amp. and doing my best to get all the speakers reasonable level, which i've just about managed with the present set up

we are really talking about using quality pa type drivers (not crap)

and blending them together...

not much of an answer...
Any suggestions around driver matching Steve its an interesting approach and I was pretty blown away by scale you were getting. As you say thios is not the usual appraoch so any more info on how to achieve this would be great
You need to keep it reasonably simple for me when it comes to reading graphs and matching I am not sure what I am looking for

[SPS]

I tend to take my speakers for granted,
scott lingren came round last night and we had a good session,
Ist set up was some lowther accousta/pm6c scott was totally supprised by the sound quality, much better than he remembered

then we moved to my latest chipboard creations, twin wharfedale w/15 + pioneer(coral) pax20e+ 1960's emi tweeter
the sound improved from the accoustas, space /detail/ box colouration/scale to a point

then swapped in my H frames, instruments where all so easy to reconise, lifelike scale and detail. nearly a live sound (i wish !!)

they are made up of twin (new) 18" fane's colosus per side, rolled off around 250 htz, lowther ex4 between 250htz and 1 khz vitavox horns do around 800htz till they fizzle out around 8khz, fostex 900a gently rolls in around 7khz

not a cheap set of drivers.. and no one in their right mind would start from scratch with them..

they are all wired up on gentle slopes, (simple) caps and/or inductors.
that really dont affect the sound quality too much ...

you can look most of the drivers and see what the response looks like
its the bass that the hard bit to get... twin 15's is where it starts in my view

my original plan was to buy single PD's 21"or 24" drivers. mark at pd was going to let me test one of my amps on them but it never happened. so i took the twin 18 route.(they are too expensive to take a chance on, which i did with the 18")

they are all wired in phase, and overlaping or widening the crossovers and moving it around, helps to smooth over the peaks and troughs that occur

now its not just the speakers that do scale and detail, the amp is just as important,

the power supply, output transformers and valves all make a difference

the output transformers i use are tribute's , globe px25 and px4 are the best audio valves i know,with the exception of early original 300a + 300b's,

my amps are very simple, and i dont use pre amps. the less in the chain the better for me..

now not every one would agree with me on my take on hi-fi kit... but that my viewpoint at the moment... ( and it's always changing!!)

getting the best from all hi fi is about putting the best components in the right places in the best way you know, when you make your own amps and speakers it can be taking that approach to the highest levels.. if you are lucky to get it something like right. audio is all compromises...

[John]

Thanks Steve
I am very happy with the sound I get but always think its good to understand other approaches I always remember the H frame baffles of yours and being impressed by the sounds you were getting. For me HiFi is all about enjoying the music and I can listen to my system for hours and still get shivers down the spine, but no such thing as Audio perfection
I sometimes wonder do we end with a system our ears and prefences deserve

[John]

A few more links
I have not heard these drivers but they are well made and should sound very good
http://www.phy-hp.com/English/Products/Drive_Units.html and baffle plan http://www.phy-hp.com/English/Communication_E/Com_E_Baffle_Plan.html
Next is an intersting arcticle around passive open baffles but most of it is way above my head
http://docs.google.com/viewer?a=v&q=cache:Yjbz1-Oas8UJ:www.quarter-wave.com/OBs/OB_Design.pdf+open+baffle+drivers&hl=en&gl=uk&pid=bl&srcid=ADGEEShQZ7TEwOwKVzQ40F3G18L7Yx4malWz4G4N2aIH EIyBoqc_iw31IXvXOjqtRxYjhgBf3kJSlWpy1nwLs4zTCKe4uq eSQo1TZsrCoHQjQIzEhJ8xuKaFRhREUh7B1Re4zX2FioAe&sig=AHIEtbQ71Y8l81Bbh9GF3uFVASzgJil27g

[SteveTheShadow]

Just seen this thread.

Here's a pic of my own open baffles, designed for a small room.

http://web.me.com/scress1958/Pictures/Blissful.jpg
Bass unit is an actively driven Eminence Delta 12, powered by one 50 watt SS subwoofer plate amp per side.
Large unit in the middle is a Goodmans Axiom 401 running full-range and relying on the baffle dimensions to roll off the bottom end to fit in above the sub amp.

Small driver above the Goodmans is a Fostex FF125K set up as a tweeter
Last of all, at the top is a twin piezo horn tweeter array to fill in the extreme top.

It works extremely well and sounds beautiful in my small living room.
Despite their size, these are the only speakers I've ever had in my 12x12 room that have not boomed in the bass.

Steve

[Reid Malenfant]

Nice setup Steve, that's still some radiating area for a small room ;) Nice looking kit to. I can see you or at least someone looks pretty relaxed, best way...

I see the cat knows where it's nice & warm :eyebrows:

[SPS]

Just seen this thread.

Here's a pic of my own open baffles, designed for a small room.

http://web.me.com/scress1958/Pictures/Blissful.jpg
Bass unit is an actively driven Eminence Delta 12, powered by one 50 watt SS subwoofer plate amp per side.
Large unit in the middle is a Goodmans Axiom 401 running full-range and relying on the baffle dimensions to roll off the bottom end to fit in above the sub amp.

Small driver above the Goodmans is a Fostex FF125K set up as a tweeter
Last of all, at the top is a twin piezo horn tweeter array to fill in the extreme top.

It works extremely well and sounds beautiful in my small living room.
Despite their size, these are the only speakers I've ever had in my 12x12 room that have not boomed in the bass.

Steve

nice picture steve, they sounded the really good at eggborough at out last meet... best i've heard them..

steve

[Mark Grant]

come and have a listen to mine if your interested..

i only live a few miles down the road..

See you later :)

[Mark Grant]

Heres some pictures of my speaker build Mark
http://theartofsound.net/forum/showthread.php?t=6143&highlight=open+baffles

http://i516.photobucket.com/albums/u327/Johnj_013/open%20baffle/openbaffleskelton.jpg

http://i516.photobucket.com/albums/u327/Johnj_013/open%20baffle/securedownload1.jpg

http://i516.photobucket.com/albums/u327/Johnj_013/open%20baffle/securedownload2.jpg

http://i516.photobucket.com/albums/u327/Johnj_013/open%20baffle/securedownload8.jpg


They look great, I have quoted the images, hope that's OK.

[John]

No worries Mark The extra thickness of the baffles really helps and not heard any speakers with better mid bass
Let me know if you wish for more techinical info around the baffles

[radio]

they look amazing clive:stalks: