Stupid question time.
I'm not saying we're approaching the following scenario with Grok's example (are we?), but it got me wondering: Is there a point where the air volume of a room is small enough relative to the size of the large horn we're attempting to use in it, that it starts messing with the acoustic impedance of the horn output, thereby messing up its response in said room? Or do I just not understand horns at all?
-- Jim, guessing the answer is 'B' 😕
I'm not saying we're approaching the following scenario with Grok's example (are we?), but it got me wondering: Is there a point where the air volume of a room is small enough relative to the size of the large horn we're attempting to use in it, that it starts messing with the acoustic impedance of the horn output, thereby messing up its response in said room? Or do I just not understand horns at all?
-- Jim, guessing the answer is 'B' 😕
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You know, I'm grappling with a lot of the helpful suggestions provided so far.
I've always thought of an exponential type horn as a classic acoustic amplifier. Like the old hearing aids and the original gramophones. I'm still a bit hung up with the simplistic notion that the larger the horn, the greater the volume for a given driver.
A lot of the designs put forward in this thread remind me of the transmission line subs I made back in the 70's and 80's. These had their appeal but lost their composure in the home theatre application. I'm sure these are an improvement, but a challenge to design for a rookie like me.🙂
While I am considering the ideas put forward, I'm still wondering what would happen if I made a vented sub box and stuck it at the end of a horn! Wouldn't the horn simply act as an amplifier?
I've always thought of an exponential type horn as a classic acoustic amplifier. Like the old hearing aids and the original gramophones. I'm still a bit hung up with the simplistic notion that the larger the horn, the greater the volume for a given driver.
A lot of the designs put forward in this thread remind me of the transmission line subs I made back in the 70's and 80's. These had their appeal but lost their composure in the home theatre application. I'm sure these are an improvement, but a challenge to design for a rookie like me.🙂
While I am considering the ideas put forward, I'm still wondering what would happen if I made a vented sub box and stuck it at the end of a horn! Wouldn't the horn simply act as an amplifier?
Maybe if you are listening in a phone booth. Don't know if they still exist...
Yes theoretically it is possible. But practically I don't really think so.
Been done. I even tried it away back when I had hair. Don't really add nuttin to the mix.
I just happen to be a carpenter/cabinetmaker when I'm not working in front of my computer doing audio design. ( I like getting away from the idiot box from time to time ) If you want a ten inch riser, are you willing to have one or two steps to get on top of it? Cuz 7 inches is a standard step. 5 inches makes for a really easy to get up onto type of step. So you could divide the total riser height with a baby step in front of it.
Greets!
Yeah, I learned the hard way with a Jensen Imperial inspired 'el cheapo' variant that without some sort of EQ, the old real estate adage 'location, location, location' ruled, so went to the small multiple sub system long before I read about it.
Cool! I'm real partial to 8"ers since they are so flexible. Because of Grok's 11" limit though, I was looking at CSS's SDX10 rather than multiples of the popular MCM 55-2421 horn driver.
FWIW WRT to riser height: HDTV Set Up THX.com
GM
Yes this is not step height for sure! I have a room with a 90" ceiling height so the bottom of my projected image is 20" from the bottom of the floor! So I am shooting for an internal riser/sub height of 11", I should end up with an overall Maximum height of 12.5" ... about the height of a typical kitchen step stool.
The ceiling is low because the garage is overhead so the ceiling is a foot thick! Three walls are earth filled too! No matter what, I'll be able to crank this thing!
Driver link.. Dayton Audio DC250-8 10" Classic Woofer
Hmm, with only a 70 W, 4.5 mm Xmax power limit and large box specs, you're sending a lot on wood, etc., for pretty mundane performance well below even the lower consumer THX reference.
GM
GM
The time alignment is going to need some adjustment. For best results keep your subs up front so the waves can expand and be in phase with the front end.
Oh have I heard this one before.
I have demonstrated horn loaded subs quite a few times and people started out by discussing the group delay issues. I even have a friend that did studies on group delay while in school.
Short answer is that no one could pick up any anomalies when listening to music. Pure tones are a different thing. And the amount of group delay can be different depending on the type of enclosure. I'd be much more concerned about the absence or presence of harmonics either generated by the driver due to the enclosure design.
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