Selecting only the part of a post you are replying to is encouraged (and not quoting at all when your post directly follows the one you are responding to). Way too many people quote entire posts (even if they only have a one word response) which does a lot to make it harder to follow a conversation.
dave
diyAudio Moderation Team
I'm totally out of my league here, and I hope that you bear with me ...
Is it correct to assume that your miniOnken cabinets are not bass reflex cabinets, but rather transmission line designs?
Your ikea bowl design above is very interesting. It looks to have openings around it's circumference, radiating out.
Not sure what I'm getting at here ...
I'm really just trying to muscle the CHP-70-P into a reasonably sized sphere, get a decent low end response, AND paint it a pale blue !!
the heart wants what the heart wants.
Better desibed as a reflex pushed toward saperiodic by the high aspect ratio, hi R vents.
Those are the vent.
For the CHP you will need to find a way to make a sphere with a net volume of 4.7+ litres.
dave
Whatever it is that isobaric does, you can achieve the same result with EQ.
Just a handful of resistors, capacitors and an opamp.
Google linkwitz transform function.
Selecting only the part of a post you are replying to is encouraged (and not quoting at all when your post directly follows the one you are responding to). Way too many people quote entire posts (even if they only have a one word response) which does a lot to make it harder to follow a conversation.
dave
diyAudio Moderation Team
Quoting out of context - Wikipedia
I'm not defending myself against obvious logical fallacies.
There was no need to moderate the posts, I was not hostile to anyone, nether was anyone hostile to me.
We're in the realms of linguistic semantics here.
The most common purpose behind adopting the isobaric load is / was size reduction; more specifically to be able to use a smaller box than would otherwise be the case for a given drive unit. Linn's Isobaric with the B139 is a good example, and marketing value aside, they adopted it because it allowed them to use one of the handful of available OEM drivers in a reasonably sized box. 😉 There weren't many other options available. With the lower Q, lower Vas units more common at present, there is little reason to use isobaric loading as excessive box size is rarely an issue. Still a few die-hards around -IIRC Neat still use it (and why not -room for all), but it's more or less gone the way of the dodo now. A tool to keep in mind if needed, but a rarely used one.
The most common purpose behind adopting the isobaric load is / was size reduction; more specifically to be able to use a smaller box than would otherwise be the case for a given drive unit. Linn's Isobaric with the B139 is a good example, and marketing value aside, they adopted it because it allowed them to use one of the handful of available OEM drivers in a reasonably sized box. 😉 There weren't many other options available. With the lower Q, lower Vas units more common at present, there is little reason to use isobaric loading as excessive box size is rarely an issue. Still a few die-hards around -IIRC Neat still use it (and why not -room for all), but it's more or less gone the way of the dodo now. A tool to keep in mind if needed, but a rarely used one.
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https://monacoustic.us/product/the-supermon-mini/
Just wanted to drop this here. It's seemingly almost exactly what OP suggested, and it does seem to have a low pass on the internal driver. It's crossed over @~7KHz to the AMT (Mundorf?)
I would be interested to hear what people think of the design on these
They're getting very good reviews, but I am curious what people think of the design in general?
Isobarik makes little sense with the selection of woofers now available. Effectively the overhead for isobarik lets you pproach a cabinet half the size. So if you have woofer sthat use too big a box the technique can be useful.
The low pass on the second driver needed as one starts to get combing effects near and above the frequency defined by the subchamber depth/2.
dave
The low pass on the second driver needed as one starts to get combing effects near and above the frequency defined by the subchamber depth/2.
dave
How does eq inhibit internal cabinet resonances from exiting the in room cone? The best audible improve I could hear in some Peerless, Scanspeak, and Dynavox isobarics I made years ago was clarity in the midrange. I don't know, but suspect tge clarity was tge result of internal cabinet resonances being lessened through the front cone because of the trapped piston of air between the two cones damping resonances from the cabinet .asking it through the internal cone. It seems to me the air trapped between may also provide ao.e reinforcement from the outside cone reacting to the weaker resonances that make it through.
I notice almost everyone uses 1/3rd or greater smoothing when posting pictures of their frequency response graphs. Maybe this is disguising the way internal cabinet pressure reactions modulate the woofer motion, which then modulates impedance, and therefore its frequency response. I have to believe if tge front cone is not exposed to this, it will be less affected by it. So an equalizer may be easier, but it wouldn't affect more than the bass, IMO.
Which is what the OP asked about. Sorry for the meander.
With isobaric you get twice the motor power.
Do you really believe eq could double the motor power?
With isobaric, a project will get double the motor power. But the moving mass and surround and spider resistance and inertia to control also double. From using it in the past, I found most of the benefits were from what I assume was the extra cone keeping a lot of the internal midrange frequencies from modulating the front cone.
I've also used clamshell isobaric in a pinch when I realized a 1.3ft3 cabinet I'd had built for me was actually just under a cubic foot, after figuring for braces and driver displacement the builder forgot about.
That was some fine bass.
I've also used clamshell isobaric in a pinch when I realized a 1.3ft3 cabinet I'd had built for me was actually just under a cubic foot, after figuring for braces and driver displacement the builder forgot about.
That was some fine bass.