Looks like a very good project. Just read the first 3 posts.
I need to go and get this cabinet built
I need to go and get this cabinet built
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I'll be the doubting thomas. I'm betting the an15 drivers want more like 8-10ft3. And 30hz sounds cleaner, deeper, faster, than tuning at 40hz and above.
If you crunched the numbers, the driver has a qts of .483 and a vas around 600L (20ft3). Yes you can make it smaller. And maybe it doesn't matter at 10 watt levels.
Norman
If you crunched the numbers, the driver has a qts of .483 and a vas around 600L (20ft3). Yes you can make it smaller. And maybe it doesn't matter at 10 watt levels.
Norman
Yes I am aware of the TS parameters.
Don't worry, I am a doubting Thomas also, but I am a curious doubting Thomas. 😀
I am also a doubting Thomas regarding TS parameters. Actually I doubt everything.
What do mean at 10 watt levels?
I don't even exceed 1 Watt
Don't worry, I am a doubting Thomas also, but I am a curious doubting Thomas. 😀
I am also a doubting Thomas regarding TS parameters. Actually I doubt everything.
What do mean at 10 watt levels?
I don't even exceed 1 Watt
In fairness to Dave, he does also have a 13.6 cubic feet cabinet.
I do have a few ideas to try with the 5.6 cab though.
Either way it will be interesting to see what the result will be
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What you get with the smaller box is a bit of hump at the low frequencies. If simulations can be believed, the hump is small, smaller than the baffle step roll off. I figure that it may even be intentional - an attempt to compensate for the baffle step, but I don't think the hump is enough to do that.
I played around with the box simulations, it does look better with more space than the 5.6 cab, but I don't know how audible this would be.
When using a box smaller than the Vas, I think it makes sense to do the experiment of stuffing the port so that it's more like an Aperiodic box. You'll be able to try this experiment easy enough.
It may also work better sealed. You can block the port altogether and try this too.
I saw one picture on the internet somewhere where the box had been designed with a big hole in it and different sized pieces of wood could be screwed over the hole to allow for different port dimensions. This sounds Melonesque...
It's going to be quite interesting!
I played around with the box simulations, it does look better with more space than the 5.6 cab, but I don't know how audible this would be.
When using a box smaller than the Vas, I think it makes sense to do the experiment of stuffing the port so that it's more like an Aperiodic box. You'll be able to try this experiment easy enough.
It may also work better sealed. You can block the port altogether and try this too.
I saw one picture on the internet somewhere where the box had been designed with a big hole in it and different sized pieces of wood could be screwed over the hole to allow for different port dimensions. This sounds Melonesque...
It's going to be quite interesting!
I have an even more melon idea, however you are starting to catch some of my brain waves. 
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Here is the response with baffle right against the wall
EDIT: I am too lazy to take another photo. Anyway it is right against the wall
EDIT: I am too lazy to take another photo. Anyway it is right against the wall
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I wondered about that ! 😱
Here's a photo of what I was describing that I found on the 'net
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I like the flat response against the wall.
Do the voices come from the floor or higher up ?
If an an15 was under the tv, I be the voices would localize to the tv.
Norman
Do the voices come from the floor or higher up ?
If an an15 was under the tv, I be the voices would localize to the tv.
Norman
The only listening tests I have done with woofer near the floor were the ones I did very early on with the baffle leaned back at a slight angle so it was on axis with ear. In that instance I did not get the feeling voices were comig from the floor.
My initial feeling though with this huge baffle is it seems to lose some of the magic of the smaller Jamo baffle but it could just be cardboard vs birch ply effect.
These are just very initial feelings.
I think the best compromise would be something like PHY baffle at around 1m to 1.2m tall and around 1.4m to 1.6m wide (total) with centre of woofer about 14" above ground height, and baffle angled slightly back wards.
When I have finished testing the 5.6 cabinet I can use the front baffle as a chassis for the PHY baffle, and see how it sounds.
At the moment I have not been listening to much music because all my time has been spent just building and measuring.
When all of these ideas have been exhausted I will start purely listening.
My initial feeling though with this huge baffle is it seems to lose some of the magic of the smaller Jamo baffle but it could just be cardboard vs birch ply effect.
These are just very initial feelings.
I think the best compromise would be something like PHY baffle at around 1m to 1.2m tall and around 1.4m to 1.6m wide (total) with centre of woofer about 14" above ground height, and baffle angled slightly back wards.
When I have finished testing the 5.6 cabinet I can use the front baffle as a chassis for the PHY baffle, and see how it sounds.
At the moment I have not been listening to much music because all my time has been spent just building and measuring.
When all of these ideas have been exhausted I will start purely listening.
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Boxes are bloody slow to build
I am doing the cut out for the woofer at the moment
EDIT: I better get back to it. I hope to finish it by today
I am doing the cut out for the woofer at the moment
EDIT: I better get back to it. I hope to finish it by today
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you are a dynamo my friend !
I have a few sheets of Birch ply in my garage as of today. I'm getting ready to start building something and it will start with the darned driver cut-out
I'm looking forward to your next instalment of results.
I have a few sheets of Birch ply in my garage as of today. I'm getting ready to start building something and it will start with the darned driver cut-out
I'm looking forward to your next instalment of results.
Just some advice regarding construction. Make the box 1.5 inches taller and put in more bracing. Use at least 1.5 inch thick for the front baffle.
don't razz him. His progress has been excellent. It takes me months to get anything done. I've seen my older buddies mean well, but it is tough to get motivated, especially as we get older. I have a friend that I bought an awesome used amp from. It went bad a year or so later, he can fix it, otherwise it would be $500 to have it shipped and fixed (going price of a working one) but he got me another one off ebay so I wouldn't be hounding him (when he'll get it fixed), now that one is acting up (5 years later).
We love to get new carpenter-ish people into audio because they get things done. We say "yea, a push pull subwoofer sounds great" and 2 days later he has one built. And it allows people like me to say "This should do (fill in the blank)" or "I haven't made it but I'd do (blank)" then what do you know, it is built and it does. His measurements of the phy open baffle are priceless to me blowing simulations out of the water. Just simple math.
The "magic" (I bet in the small baffle) is the front wall bounce that dipole fans usually find intoxicating. To me, the sound interacts with the room (like someone speaking) more than simple speakers in a box. The brain likes what it hears (the bass and mids go everywhere) and says yes, the sound cues for the music being played match this room (better than what is in the recording).
Just a theory I've been working on.
I bet 90% (or more) of people prefer the narrow baffle compared to a large baffle. I've even read people say that huge open baffles create a "black hole in the middle sound" (not necessarily the folded open baffle though). That to me this hole of sound is a lack of a front wall center bounce ( a false sound compared to the recording). Sort of where you can add to much stuffing (we like some of it, not sounding so dead). Or how you kill a room with sound absorbing material on every wall, it sounds so dead it is uncomfortable, although it would be more "correct".
Boxes are bad, they usually add something that you may or may not find annoying. Even my big dual 15's add a chestyness not present in the recordings. I easily hear it on movie theater speakers also. Yes the bass from a box always helps, but in the back of your mind, you know that the voice would sound better on the open baffle (because it does).
Norman
We love to get new carpenter-ish people into audio because they get things done. We say "yea, a push pull subwoofer sounds great" and 2 days later he has one built. And it allows people like me to say "This should do (fill in the blank)" or "I haven't made it but I'd do (blank)" then what do you know, it is built and it does. His measurements of the phy open baffle are priceless to me blowing simulations out of the water. Just simple math.
The "magic" (I bet in the small baffle) is the front wall bounce that dipole fans usually find intoxicating. To me, the sound interacts with the room (like someone speaking) more than simple speakers in a box. The brain likes what it hears (the bass and mids go everywhere) and says yes, the sound cues for the music being played match this room (better than what is in the recording).
Just a theory I've been working on.
I bet 90% (or more) of people prefer the narrow baffle compared to a large baffle. I've even read people say that huge open baffles create a "black hole in the middle sound" (not necessarily the folded open baffle though). That to me this hole of sound is a lack of a front wall center bounce ( a false sound compared to the recording). Sort of where you can add to much stuffing (we like some of it, not sounding so dead). Or how you kill a room with sound absorbing material on every wall, it sounds so dead it is uncomfortable, although it would be more "correct".
Boxes are bad, they usually add something that you may or may not find annoying. Even my big dual 15's add a chestyness not present in the recordings. I easily hear it on movie theater speakers also. Yes the bass from a box always helps, but in the back of your mind, you know that the voice would sound better on the open baffle (because it does).
Norman
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