[scorpion]

Brian,

It is nice to have been inspirational to such a colourful design. Myself I never produce at this skilful level. Just some wood panels here and some MDF there.
In speakerwork you have to compromise somewhere and your baffles certainly have rigidity enough to cope with elements involved, but my first priority would be to separate bass and mid/tweeter baffles from each other. This effort has the potentially best effect of influence sound heard most positive.

For a passive design this might be a bit out of reach. But so is not really magnet mount and woofer isolation from the baffle. This would be a second best option.
For layered baffles the best glue to use would be a damping glue like the SWEDAC DG-A2, used by world leading speaker manufacturers, or the US type Green Glue which seem to have similar characteristics to produce resonance free baffles.

I recommended the TB 1808 as a possible candidate for a sole fullranger OB panel, but that recommendation was based on speaker specs only not by any own experience. But this unit have been praised by others.

I think Studiotech - Greg has a most valid point when he asserts that our brains adapt to what we hear in a way to cheat us to believe what we hear is alright. There are studies showing that this adaption doesn't take even half an hour if there are no obviouse faults. I experienced this when changing from Eminence Alpha15 to AE IB15 in my Blindstone baffle. From the first note out from the IB15s I recognized this was the better speaker in comparison. And it also explains why some of my experienced Swedish Hi-Fi Forum friends have been less impressed by my Alpha15 designs than they were about the first 'Volks-OB'.

For passive OB you don't have much choice and the Alpha15s are not bad but overvalued compared to cleaner woofers. Worse is perhaps that it tends to leak high frequency with too simple crossover filters. I was made pretty aware of this with my MJAO speaker which I had to go real long to get it silenced. It is all in the  'MJAO' thread.

Otherwise I think the B&G Neo3 is an excellent speaker, not betterd by any near in price.

Now how encouraging was this. In fact it is meant more philosofical about speaker design in general than specifically about your speakers. And as your speakers already run circles around anthony gallo 3.1 they must be good. And speakers like you say are for personal preference. Everybody doesn't listen to the same music and in the same way as I do.

/Erling

[brian t]

Erling,nice to hear from you one of the reasons i tried the alpha 15a was because i needed the speaker fairly easy to drive with my 22w se valve amp have been down the active xover route before and subwoofer and have come to the conclusion that its best to keep things as simple as possible even though in my case i realise at the moment this speaker in its current configeration would be described  by most people as flawed apart from padding down the neo 3 and playing around with the capacitor value i wont be changing much on the xover front , i have had lots of speakers over the years. gallo 3.1/ apogee stage/ avantgarde uno/naim sbl/revel gem. and guess what? they all sound totally different virtually one extreme to the other so i thought i would try and build a speaker just for my ears.as i said  before i dont have much of a clue about speaker design but in some respects that maybe an advantage as i dont have too many preconceived ideas i just suck it and see. regarding the driver coupling i have taken gregs advice and am at the moment building a brace for the baffle.

[brian t]

Greg, have started building the brace it wont be quite as you advised ,but where would the fun be otherwise? my brace needs to be removable for no other reason than the alpha is mounted from the rear, i will be taking your advice regarding the implementation of mechanical grounding the drivers via the brace mine will incorporate an adjustable mechanism with varible torqe sounds grand but its quite simple and will be  informative to have a different version of your idea hope to have it done in about a week . The alpha driver basket is very resonent as you say greg i am going to try another approach by attaching aluminium blocks to each 6 sections via a compound so we will see how that pans out. 

[scorpion]

Hi Brian,

Thanks for the answer. Just go your way, mate. 

/Erling

[studiotech]

Greg, have started building the brace it wont be quite as you advised ,but where would the fun be otherwise? my brace needs to be removable for no other reason than the alpha is mounted from the rear, i will be taking your advice regarding the implementation of mechanical grounding the drivers via the brace mine will incorporate an adjustable mechanism with varible torqe sounds grand but its quite simple and will be  informative to have a different version of your idea hope to have it done in about a week . The alpha driver basket is very resonent as you say greg i am going to try another approach by attaching aluminium blocks to each 6 sections via a compound so we will see how that pans out.

I can't take credit for any brace or "grounding" ideas.  That's Ric.  I'm the non-tweaky guy, who starts with the right parts.  Just poking fun with ya.   

Greg

[Nyal Mellor]

How did you get the gloss finish? I am no expert when it comes to wood finishing but yours looks super professional and great.

[Bob in St. Louis]

I think he mentioned wet sanding earlier.

[ebag4]

I think he mentioned wet sanding earlier.

And 15 coats of white!!

Best,
Ed

[versus rider]

thanks for the tip, had problems in the past with the edges swelling several weeks
after painting. Just about to finish my open baffles with some expensive paint and don't want a repeat of last time.

when dealing with mdf i have found it best to treat the wood first before you put the primer on i use a wood hardner it tends to keep the mdf stable with less problems later when painting

[planet10]

cheers lin, happy to receive any comments good or bad as long as they are constructive.

I note that you have the 1808 in quite a tunnel. You should be able to open up the mids by putting a serious champher on this (we use a 45 degree champher even on 12mm thick baffles)

dave

[planet10]

Break-in happens MORE to ones ears than it does to the drivers.

There is cetainly some of that, but it is a myth that most of it is physcological. One only needs to directly compare a well broken in build with the same build with fresh drivers to satisfy themselves of that.

dave

[brian t]

hi guys, if you use the wood hardner it will reduce the risk of the mdf swelling a problem when you glue two pieces together and find the join shows through a few weeks later to ruin your nice finish! been there done that very annoying, i go a bit over the top with paint mainly because i buy it cheap on ebay so you might as well use it all up and if you have a standard shape half the amount i used will be fine, if anyone wants me to go into more detail regarding the finish i am happy to. the tunnel for the tweeter yep i should have routed the back out,isnt it always the way you always forget to do something on a project.one thing i have got right is suspending the tweeter on silicone major reduction in vibration just put your hand on the faceplate then on the baffle what a difference.

[brian t]

please keep your ideas comming guys as this is very much work in progress and hopefully will help anyone else doing something similar.

[planet10]

the tunnel for the tweeter

Is the tweeter a dipole?

I was talking about the W8.

dave

[brian t]

dave yep  of course you were,yes i took the back off the neo3 tweeter  but i should have put a chamfer on it just forgot to do it ,will do it on both when i get the design sorted.cheers

[versus rider]

Hi, tried a google search for that beautiful amp you have but could not find it, any links?

[face]

please keep your ideas comming guys as this is very much work in progress and hopefully will help anyone else doing something similar.

Beautiful build, but you need one of these: http://www.parts-express.com/pe/showdetl.cfm?Partnumber=390-790

[brian t]

face, yep you could be right that would be handy might be tempted later on although i suspect it would end up making the xover a lot more complicated than i may need as once you get this sort of software its natural to try and get the best response you can and you tend to end up with a speaker that is far removed from what you started out with, i would like to voice this speakers with my ears rather than have some software tell me what i have is wrong, i always think about the humble bumble bee when i reach this stage of a project, according to airodynamics it should not be able to fly but it does! thanks for info it does makes things easier i must admit .

[brian t]

face is it very difficult to use, must admit you seem to get a lot for the money and could be handy for other projects in the future thanks for letting me know about it

[brian t]

details on the 845/5 amp are here isyx.com i have the 845/300B version its a great bit of kit 40kgs 22 watt i paid $1195 inc shipping absolute bargain