They're different & have different sonic properties. Generally 126 = Mikasa, 127 = Harvey.
However, Harvey is designed to be a generic cabinet, and the 126 will do decent service, especially following this recent round of modifications. In fact, both the back-chamber volume and the tuning frequency of Harvey are similar to the Fostex BR boxes for the 126/7, so she's not pushing the driver any harder than those do, and will give a much larger sound as well, given the large quantites of air the vents couple to.
However, Harvey is designed to be a generic cabinet, and the 126 will do decent service, especially following this recent round of modifications. In fact, both the back-chamber volume and the tuning frequency of Harvey are similar to the Fostex BR boxes for the 126/7, so she's not pushing the driver any harder than those do, and will give a much larger sound as well, given the large quantites of air the vents couple to.
Hello,
First time poster here. These are my prototype Bruces. I saw Dave's early design plans in some topic here and decided to make them. I took some measurements from the original Bruce plans.
They are made from 18mm plywood using jig saw. It was a lot of work to cut 44 u-shaped pieces, clue them together and grind them even. I'm still working on them trying to decide how to finish them. Speaker element is FE206
They sound natural, excellent with acoustic material. Badly produced studio albums are a pain in the a#$ to listen, usually because there's too much compression and the sound is flat. I think these speakers needs a pair of woofer to the bottom end but all the rest is well balanced.
These are my first fullrangers ( if not included hivi-b3n dipoles on my desktop ) and I fell in love with them. Now it's easy to enjoy the music, sit back, have a drink and relax.
--
Tuomas
First time poster here. These are my prototype Bruces. I saw Dave's early design plans in some topic here and decided to make them. I took some measurements from the original Bruce plans.
They are made from 18mm plywood using jig saw. It was a lot of work to cut 44 u-shaped pieces, clue them together and grind them even. I'm still working on them trying to decide how to finish them. Speaker element is FE206
They sound natural, excellent with acoustic material. Badly produced studio albums are a pain in the a#$ to listen, usually because there's too much compression and the sound is flat. I think these speakers needs a pair of woofer to the bottom end but all the rest is well balanced.
These are my first fullrangers ( if not included hivi-b3n dipoles on my desktop ) and I fell in love with them. Now it's easy to enjoy the music, sit back, have a drink and relax.
--
Tuomas
Attachments
Hi,
I have been listening them for about 2 weeks now, first as a dipole and now few days in BVR. It might be that they gain more bass after a few weeks of more listening. But what I meant with the bottom end was the lowest register below 30Hzish. I know that not many recordings have that low sounds but in my opinion subs always give that "presense" feeling, brings you closer to the music.
It might be the really big living room that the speakers are situated in what makes the lowest notes too quiet. I'll have to dig deeper and find out. With most of the music the speakers are just superb.
Did my attachents come through? I can't see them yet, or are they still under moderation? And yes of course you can use them on Frugal-horn site. I'll take some brighter pics tomorrow.
--
Tuomas
I have been listening them for about 2 weeks now, first as a dipole and now few days in BVR. It might be that they gain more bass after a few weeks of more listening. But what I meant with the bottom end was the lowest register below 30Hzish. I know that not many recordings have that low sounds but in my opinion subs always give that "presense" feeling, brings you closer to the music.
It might be the really big living room that the speakers are situated in what makes the lowest notes too quiet. I'll have to dig deeper and find out. With most of the music the speakers are just superb.
Did my attachents come through? I can't see them yet, or are they still under moderation? And yes of course you can use them on Frugal-horn site. I'll take some brighter pics tomorrow.
--
Tuomas
WOW! Stunning artistry! That's one of the most impressive builds yet! 
Yes, you're going to need dedicated subs for below 30Hz I'm afraid: I designed Bruce to be good to 40Hz, which (aside from the lower organ racks) covers the full range of acoustic music (& most electric too come to think of it). I'm really glad you're liking what they do above the sub-bass regions though -makes it all worthwhile.
If you want to go for a sub, then at the risk of being blatent (& assuming your ceilings are high enough) I'd suggest a 12in CSS Subduction driver in the pipe-horn Dave & I did. IIRC, I did a tapped horn for them too, which has a little less extension, and a wad of extra gain, but I don't think Dave's had chance to get that one drawn up yet. I've just innundated him with a load more box designs too...
Being laid up after an op. has it's benefits: you can let your imagination run riot. 
Not sure if Dave would agree though when a flood of dimensions & ideas suddenly appear in his in-tray.
Best wishes
Scott
Yes, you're going to need dedicated subs for below 30Hz I'm afraid: I designed Bruce to be good to 40Hz, which (aside from the lower organ racks) covers the full range of acoustic music (& most electric too come to think of it). I'm really glad you're liking what they do above the sub-bass regions though -makes it all worthwhile.
If you want to go for a sub, then at the risk of being blatent (& assuming your ceilings are high enough) I'd suggest a 12in CSS Subduction driver in the pipe-horn Dave & I did. IIRC, I did a tapped horn for them too, which has a little less extension, and a wad of extra gain, but I don't think Dave's had chance to get that one drawn up yet. I've just innundated him with a load more box designs too...
Being laid up after an op. has it's benefits: you can let your imagination run riot. Not sure if Dave would agree though when a flood of dimensions & ideas suddenly appear in his in-tray. Best wishes
Scott
Beautiful tpakkanen
I think the time cutting the layers was very well spent.
ScottMoose/Dave
The laminated construction of the centre is becoming popular, It might be worth developing some template drawings for the Bruce/Harvey family. What to call a curvy variant of the Bruce... Elvis?
I'll do some scribbling today to work out how much timber I'll need for this type of construction, I have a 38mm thick sheet of particleboard that I've been lugging around for years.
I presume the critical points to keep the same are:
chamber volume, cross sectional area of each end of the horn and the approximate expansion rate of the horn.
How important is the bit of wood stuck in the middle of the opening? is that only a brace?
I'd like to lift the whole centre section 100mm higher to get the driver further off the floor. The floor makes the cabinet asymmetrical acoustically anyway so this shouldn't be too bad should it?
I think the time cutting the layers was very well spent.
ScottMoose/Dave
The laminated construction of the centre is becoming popular, It might be worth developing some template drawings for the Bruce/Harvey family. What to call a curvy variant of the Bruce... Elvis?
I'll do some scribbling today to work out how much timber I'll need for this type of construction, I have a 38mm thick sheet of particleboard that I've been lugging around for years.
I presume the critical points to keep the same are:
chamber volume, cross sectional area of each end of the horn and the approximate expansion rate of the horn.
How important is the bit of wood stuck in the middle of the opening? is that only a brace?
I'd like to lift the whole centre section 100mm higher to get the driver further off the floor. The floor makes the cabinet asymmetrical acoustically anyway so this shouldn't be too bad should it?
Yes, the panel in the mouth is just a brace.
A template for lamiated, curved finishing? Not a bad idea that, as & when Dave has time to draw them! I think we'd keep the Bruce name though -just add the option of it being constructed so as to make curved panels.
Easier still (albeit a trifle expensive...) would be to layertone the whole box out of CNC machined MDF or plywood... thank you Gemme Audio & goodnight
Lifting it up should be fine, though you might reduce LF gain a bit as you'll loose floor-loading of the lower vent-mouth.
A template for lamiated, curved finishing? Not a bad idea that, as & when Dave has time to draw them! I think we'd keep the Bruce name though -just add the option of it being constructed so as to make curved panels.
Easier still (albeit a trifle expensive...) would be to layertone the whole box out of CNC machined MDF or plywood... thank you Gemme Audio & goodnight
Lifting it up should be fine, though you might reduce LF gain a bit as you'll loose floor-loading of the lower vent-mouth.
Scottmoose said:
It has already earned the name "Curvy Bruce"... i'm happy to share the drawings, you'd either need a CNC or print them full size to take full advantage, but i could put the pattern for the inner bit on a grid to accomodate hand-tacing (as they do in wood-working magazines)... the outer part is straight with (IIRC) a 12" (300mm) radius on the corners.
These inner bits have a fit-by eye curve, and the CC is maxed out with the intention that it will have solid "Blocks" glued to the inside walls (particularily the flat ones), to make a dramatically irregular enclosures. Of course if you were using the CNCed layer approach you could just leave more wood behind -- the drawings were originallly done for a barrel stave build.
"blocks" would likely best be long skinny pyramids.
These aren't high in the queue... as Scott says he has me stacked up with drawings -- including Harvey 1v1 (and Bruce & Iris 1v1 not far behind), and i have to squeeze those in around paying work. If you have a specific need mail me and i'll see if i can get curvey BVR patterns out for anyone serious at building a set.
dave
I couldn't sit still... the treatment of the outer shell is different than Tuomas' -- Scott would need to get a detailed linear approximation of each into MathCad to suggest which shape has an edge, if either. Grid is 1", green bit is an illustration of how it is being broken up into barrel staves.
dave
dave
Attachments
Thanks for the positive comments, it's always nice to hear your work is appreciated.
Dave,
What do you suggest for damping material? Some cloth behind the chamber maybe? What about suprabaffle, any help? There have been no reason to tweak the speaker yet because I'm really pleased with the sound. I'll have to do some comparison with my headphones.
The "Curvy Bruce" drawings looks good. Now I will go and take some more fotos, there's a hint of sun outside.
--
Tuomas
Dave,
What do you suggest for damping material? Some cloth behind the chamber maybe? What about suprabaffle, any help? There have been no reason to tweak the speaker yet because I'm really pleased with the sound. I'll have to do some comparison with my headphones.
The "Curvy Bruce" drawings looks good. Now I will go and take some more fotos, there's a hint of sun outside.
--
Tuomas
Bruce v1.1 mods now complete. I was wrong when I said we can't get the response much flatter... Minor throat modification, and reprofiling of one section, bringing a slightly parabolic effect to the final expansion. The FE207E and the F200a are the primary drivers the cabinet is designed to accept, with the potential for using the 206E, 206ES-R or 208ESigma if you're willing to accept a slight compromise.
Final piece in the jigsaw for revisions is Loreena, then the BVRs will be as good as we can get them for the moment.
Final piece in the jigsaw for revisions is Loreena, then the BVRs will be as good as we can get them for the moment.