Well yes, what can you expect of the left coast? 😛
But the ladies generally like a tall, slim speaker as opposed to a short fat one. So 2x12 on a 14~15" wide baffle as opposed to 1x15" on a 17-18" wide baffle should be a winner.
But the ladies generally like a tall, slim speaker as opposed to a short fat one. So 2x12 on a 14~15" wide baffle as opposed to 1x15" on a 17-18" wide baffle should be a winner.
Stuey,
independently from OB i think
distributing a given cone area among more woofers
is always interesting, because you can save moved mass.
With same stability of the membrane the area of a cone
is proportional to r^2 while the mass is usually proportional
to something like r^3 ...
The more mass moved with the cone, the more unwanted
vibration of the baffle and the need to stabilize it.
You may have a look at www.dipol-audio.de concerning that.
Furthermore using more than one driver, the response of the
OB can be smoothed, if you are willing to experiment with
the placement of the woofers on the baffle.
Although this is not very interesting if your wooofer runs as pure
subwoofer ...
I would not recommend using an OB as subwoofer anyway.
Efficiency is very low, so you need extraordinary large
displacement volume to achieve practical SPL .
For dipole bass <100 Hz a U-Frame or H-Frame placed in the
edge of the room is far more interesting ...
independently from OB i think
distributing a given cone area among more woofers
is always interesting, because you can save moved mass.
With same stability of the membrane the area of a cone
is proportional to r^2 while the mass is usually proportional
to something like r^3 ...
The more mass moved with the cone, the more unwanted
vibration of the baffle and the need to stabilize it.
You may have a look at www.dipol-audio.de concerning that.
Furthermore using more than one driver, the response of the
OB can be smoothed, if you are willing to experiment with
the placement of the woofers on the baffle.
Although this is not very interesting if your wooofer runs as pure
subwoofer ...
I would not recommend using an OB as subwoofer anyway.
Efficiency is very low, so you need extraordinary large
displacement volume to achieve practical SPL .
For dipole bass <100 Hz a U-Frame or H-Frame placed in the
edge of the room is far more interesting ...
Pano, I have been thinking (in trying to reduce width) also of using those Peerless 830669's in a sealed box crossed over low to an OB full range or MT baffle on top, similar to Tony Gee's Modulus (or many others).
It so happens I have a couple of excellent well made boxes the perfect size for a sealed box for the Peerless, sitting in my shed...
But I feel I'd be missing half of why people love OB's.
Linearray, I hadn't decided on the crossover point between the woofers and fullrange yet - it depends on what I bought for the upper range. Anywhere between 150 and 500 Hz I'd imagine.
Thanks for all the comments.
It so happens I have a couple of excellent well made boxes the perfect size for a sealed box for the Peerless, sitting in my shed...
But I feel I'd be missing half of why people love OB's.
Linearray, I hadn't decided on the crossover point between the woofers and fullrange yet - it depends on what I bought for the upper range. Anywhere between 150 and 500 Hz I'd imagine.
Thanks for all the comments.
Baffles
My wife could not put up with the size so I went with 450mm x20mm pine, with MDF attached to the back. I am running two 15" drivers. One dual cone and one woofer in each.
And going to use Rod Elliots cross over boards.
My wife could not put up with the size so I went with 450mm x20mm pine, with MDF attached to the back. I am running two 15" drivers. One dual cone and one woofer in each.
And going to use Rod Elliots cross over boards.
Stuey ?? Do you already have the Peerless woofers?
830669 is one of those driver I always want to try. they model really quite well in a reasonably sized sealed box
Don't know if you are going to cross active or not? But if you are then perhaps the Blackwood scenario is the best solution, use a bass-midrange that is happy crossing low around 120 and use a very low crossing tweeter, but this may then need BSC which question others are qualified to answer but not me
830669 is one of those driver I always want to try. they model really quite well in a reasonably sized sealed box
Don't know if you are going to cross active or not? But if you are then perhaps the Blackwood scenario is the best solution, use a bass-midrange that is happy crossing low around 120 and use a very low crossing tweeter, but this may then need BSC which question others are qualified to answer but not me
Ted, the Blackwoods (and Aethers similarly) actually started me on the road to OB thinking.
I don't have the drivers yet, but I have been thinking they might be the best compromise. And the boxes I have already are just over 65 litres. Peerless recommend 70 litres for that woofer in sealed, so I reckon I could get away with it and save some hassles building, to boot. Turned sideways, they are the perfect size. I'd just have to replace the existing baffles (which would then be the side). I have no issue with building boxes (I've built a few) but I'm being lazy! And these are 1" MDF, so are pretty chunky.
I like the idea of a woofer crossing to a full ranger at the right frequency to cover BSC as well. Trouble is, many of the FR's are low efficiency - I'd try the CSS FR125 but it's 85dB efficient. So I've started looking at Fostexes.
I'd prefer a simple passive crossover, but I'm also considering Rod Elliott's actives...in between looking at Behringers.
But I'd still prefer a proper OB judging by what people say about them.
These are all just ideas. I'm a way off deciding as I want these to be pretty good. I've got power amps, pre's and phono's on the go too, so I want to be satisfied for at least...oh.....six months. 😉
Cheers
Stuey
I don't have the drivers yet, but I have been thinking they might be the best compromise. And the boxes I have already are just over 65 litres. Peerless recommend 70 litres for that woofer in sealed, so I reckon I could get away with it and save some hassles building, to boot. Turned sideways, they are the perfect size. I'd just have to replace the existing baffles (which would then be the side). I have no issue with building boxes (I've built a few) but I'm being lazy! And these are 1" MDF, so are pretty chunky.
I like the idea of a woofer crossing to a full ranger at the right frequency to cover BSC as well. Trouble is, many of the FR's are low efficiency - I'd try the CSS FR125 but it's 85dB efficient. So I've started looking at Fostexes.
I'd prefer a simple passive crossover, but I'm also considering Rod Elliott's actives...in between looking at Behringers.
But I'd still prefer a proper OB judging by what people say about them.
These are all just ideas. I'm a way off deciding as I want these to be pretty good. I've got power amps, pre's and phono's on the go too, so I want to be satisfied for at least...oh.....six months. 😉
Cheers
Stuey
Hi !
I also have similar problem with deciding which option to use...
I currently run one 15" alpha on U baffle and vintage alnico oval FR, and i am pleased with amount of bass, but i would like some 1 or 2 db's louder and also deeper bass (man is so easy to spoil 🙂 ).
I had in my mind this option
Is this appropriate mounting of 2x15" woofer's on H baffle ?
Would this give me desired ~2db gain, and deeper bass comparing to U baffle with only one Alpha15''?
Cheers !
I also have similar problem with deciding which option to use...
I currently run one 15" alpha on U baffle and vintage alnico oval FR, and i am pleased with amount of bass, but i would like some 1 or 2 db's louder and also deeper bass (man is so easy to spoil 🙂 ).
I had in my mind this option
An externally hosted image should be here but it was not working when we last tested it.
Is this appropriate mounting of 2x15" woofer's on H baffle ?
Would this give me desired ~2db gain, and deeper bass comparing to U baffle with only one Alpha15''?
Cheers !
Hey Stuey and the lads.
Yeah, the Peerless models OK in 65 L sealed. Gives you a Qtc of about 0.72 and an F3 of ~48Hz. That's about as low as the F3 goes either sealed or IB. Be sure to stuff the hell out of it, it makes the box look bigger.
It evens models decently in a BR of 65L (about 2.3ft). Smaller than it should be, but OK. F3 of 39Hz if you tune the box to 31Hz. So you could try both and decide which you like.
One advantage the box has over OB is no lack of bass, so you won't need to do funky crossover tricks to make up for the rising response. Just use a normal crossover where it's needed. Of course you can use bit of EQ to extend the bass.
Then you could use a fullrange driver at the top.
People will get sick of me saying it, but you should certainly check out the
Lampizator Site. and also his Endorphin Project.
An easy way to do it, and it works great. Just pick the right drivers. =)
Merry Christmas from snowy Portland.
Yeah, the Peerless models OK in 65 L sealed. Gives you a Qtc of about 0.72 and an F3 of ~48Hz. That's about as low as the F3 goes either sealed or IB. Be sure to stuff the hell out of it, it makes the box look bigger.
It evens models decently in a BR of 65L (about 2.3ft). Smaller than it should be, but OK. F3 of 39Hz if you tune the box to 31Hz. So you could try both and decide which you like.
One advantage the box has over OB is no lack of bass, so you won't need to do funky crossover tricks to make up for the rising response. Just use a normal crossover where it's needed. Of course you can use bit of EQ to extend the bass.
Then you could use a fullrange driver at the top.
People will get sick of me saying it, but you should certainly check out the
Lampizator Site. and also his Endorphin Project.
An easy way to do it, and it works great. Just pick the right drivers. =)
Merry Christmas from snowy Portland.OB dual or single woofer
Your project sounds promising. I am working on an open baffle also, but am not constricted by baffle width or WAF, but rather by sloping ceiling side walls.
In any case, if your budget would allow, I would vote for either 2 of the 12's, or better yet, 2 of the 15's.
Since you are looking at a full range plus woofer(s), it will not result in an overly tall speaker if you stack the woofers vertically. I have noticed over the years that many women like the look of Martin Logan speakers...if you keep the baffle as narrow as possible, and go vertical it should give a pleasing look.
I would like to hear from more knowledgeable persons what the effect would be of having one woofer mounted on the baffle, and another woofer behind it in an open box box, either firing forward, or backward. (Open isobaric?)
Good luck on your project!
Your project sounds promising. I am working on an open baffle also, but am not constricted by baffle width or WAF, but rather by sloping ceiling side walls.
In any case, if your budget would allow, I would vote for either 2 of the 12's, or better yet, 2 of the 15's.
Since you are looking at a full range plus woofer(s), it will not result in an overly tall speaker if you stack the woofers vertically. I have noticed over the years that many women like the look of Martin Logan speakers...if you keep the baffle as narrow as possible, and go vertical it should give a pleasing look.
I would like to hear from more knowledgeable persons what the effect would be of having one woofer mounted on the baffle, and another woofer behind it in an open box box, either firing forward, or backward. (Open isobaric?)
Good luck on your project!
Cheers Pano. Much food for thought.
My problem is I wake up each morning leaning a different way!
I've seen the Lampizator site from your recommendations elsewhere.
Merry Christmas to you too.
(Snow would be nice. I took the kids down to the local beach yesterday in 38C. Had to be careful as there was a load of tiger sharks feeding on a whale just offshore.)
Cheers
Stuey
My problem is I wake up each morning leaning a different way!
I've seen the Lampizator site from your recommendations elsewhere.
Merry Christmas to you too.
(Snow would be nice. I took the kids down to the local beach yesterday in 38C. Had to be careful as there was a load of tiger sharks feeding on a whale just offshore.)
Cheers
Stuey
Heck~!! build both and pick the ones you think sound the best, and yes, I keep changing my mind too, drives "herself" mad-mad-mad.
From my experiments so far OB is great except for that /those last two octaves at the bottom, but from 100 on up, they do sound 'better'
From my experiments so far OB is great except for that /those last two octaves at the bottom, but from 100 on up, they do sound 'better'
Hmmmmm....the Beta 15A is recommended by Eminence for 45-62 litres sealed...sideways firing it'll fit....get the 15 in the house...get Mrs Stuey used to it....make the sealed box first then produce 'wide OB by stealth'.
She won't even notice.
Stuey
She won't even notice.
Stuey
Hey, well, yeah. 😀
I worked it the other way 'round. Built giant first -- "just testing dear!" -- then everything else seemed small and cute.
I worked it the other way 'round. Built giant first -- "just testing dear!" -- then everything else seemed small and cute.
Those do look nice.
Could be the 18 Sound horn, looks like it - except that it's shiney plastic. Isn't the 18 Sound horn metal?
Could be the 18 Sound horn, looks like it - except that it's shiney plastic. Isn't the 18 Sound horn metal?
Moondog55 said:
Some of their 3-ply is quite good. Beautiful continuous grain. Not nearly big enough for structural work, but an alternative to veneer and much easier to work with.
OK Jon, I stand corrected, yes I use their Luan face plys as decorative, although it is easier to work with it is dearer than the veneers Bunnings sell
Their structural plys seem to be full of voids and cracks. Also it is simply cheaper to go to a decent supplier and buy full sheets and have them cut to size accurately
Their structural plys seem to be full of voids and cracks. Also it is simply cheaper to go to a decent supplier and buy full sheets and have them cut to size accurately
Hmmm...I didn't know Bunnings sold veneer, either. I might have to start opening my eyes a bit. I've been looking at using veneer on this project.
Ted, Jaycar here has 5 of those woofers, $24.95 each.
Stuey
Ted, Jaycar here has 5 of those woofers, $24.95 each.
Stuey
Well do you need a spare, I've managed to get all that I need.
Would you be willing to spend $100 or an experiment??
2 of those OB will take 5or6 watts///10 watts before exceeding XLim, but in a small to medium room thats Ok, put a nice old paper 6inch wide range and a small tweeter on a 450 X 900 baffle and it will take a lot of beating SQ wise, just don't expect to rattle the windows.
Not all Bunnings aparently but the shop down the road does, only a few types and most paper backed, Honestly I've not ever used veneer, always thought it was in the too hard basket.
In fact I'm tempted to go down the shed and knock up a quick test to show you
Would you be willing to spend $100 or an experiment??
2 of those OB will take 5or6 watts///10 watts before exceeding XLim, but in a small to medium room thats Ok, put a nice old paper 6inch wide range and a small tweeter on a 450 X 900 baffle and it will take a lot of beating SQ wise, just don't expect to rattle the windows.
Not all Bunnings aparently but the shop down the road does, only a few types and most paper backed, Honestly I've not ever used veneer, always thought it was in the too hard basket.
In fact I'm tempted to go down the shed and knock up a quick test to show you
Stuey, do you have a definite midrange in mind??
If you build with the jaycar papers you may not want to over capitaize on the mid, good but not too good.
I have available for a test run the folloing to choose from
Vifa P11/P13/M11
Jaycar 5inch polycone/4inch polycone( nice but only a 84dB)
Foster 8inch widerange ( nice and 88dB)
Coral 6inch widerange Alnico ( for sale $12- plus postage)
I'm waiting for paint and glue dry at the moment so I can play for a couple of hours each day
If however you go sealed with OB mids then I think you would need a really good quality mid may be a single 6inch
If you build with the jaycar papers you may not want to over capitaize on the mid, good but not too good.
I have available for a test run the folloing to choose from
Vifa P11/P13/M11
Jaycar 5inch polycone/4inch polycone( nice but only a 84dB)
Foster 8inch widerange ( nice and 88dB)
Coral 6inch widerange Alnico ( for sale $12- plus postage)
I'm waiting for paint and glue dry at the moment so I can play for a couple of hours each day
If however you go sealed with OB mids then I think you would need a really good quality mid may be a single 6inch
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