I was just thinking and was wondering why there are not more downfring subs. It seems like it would be the better way to go, since whenever I have used or installed them they always seem to make room placement a bit more flexible, and there doesn't seem to be any downfall sound quality wise.
So why do the majority of the subwoofers out there tend to be front-firing? What ARE the downfalls of a down-firing sub? What are the advantages of front-firing? Does one really outweigh the other, or have manufacturers found a consumer preference to follow?
I was wondering because I am going to build a 15" sub today with a Dayton driver I have had laying around for a while, powered by an outboard Crest Audio PA amplifier, using the bass management tools in my Sony ES STR-DA777ES. I might try for downfiring unless I find there is good reason to avoid that.
So why do the majority of the subwoofers out there tend to be front-firing? What ARE the downfalls of a down-firing sub? What are the advantages of front-firing? Does one really outweigh the other, or have manufacturers found a consumer preference to follow?
I was wondering because I am going to build a 15" sub today with a Dayton driver I have had laying around for a while, powered by an outboard Crest Audio PA amplifier, using the bass management tools in my Sony ES STR-DA777ES. I might try for downfiring unless I find there is good reason to avoid that.
I really do believe that "cone sag" is only a myth.
If the suspension is that weak and floppy, then you shouldn't even be using that driver anyway. Unless the cone is made out of cast iron and the magnet is the size of a silver dollar, I wouldn't worry or be concerned about driver placement due to sagging.
As for having a down-firing or front-firing sub, I prefer front-firing. Down-firing subs tend to sound a bit muffled and sloppy, and even a bit boomier.
Front-firing subs, however, seem to be more crisp and precise with very tight attack. It just sounds cleaner to me.
In fact, that's why I decided to build the H-frame dipoles instead of the Pheonix style, and once again, it seems to have worked out for the better!
If the suspension is that weak and floppy, then you shouldn't even be using that driver anyway. Unless the cone is made out of cast iron and the magnet is the size of a silver dollar, I wouldn't worry or be concerned about driver placement due to sagging.
As for having a down-firing or front-firing sub, I prefer front-firing. Down-firing subs tend to sound a bit muffled and sloppy, and even a bit boomier.
Front-firing subs, however, seem to be more crisp and precise with very tight attack. It just sounds cleaner to me.
In fact, that's why I decided to build the H-frame dipoles instead of the Pheonix style, and once again, it seems to have worked out for the better!
chops said:
I hate to say it, but that's probably either IM distortion in the cone creating upper harmonics to the bass, or the upper bass frequencies still in the passband of the Xover, that are filtered out when listened to indirectly.
Regarding the sagging:
Some many, many years ago I made a large coffee table with four down-firing CTS 12W19 Woofers - 12", heavy cone and a free air resonance of about 15Hz.
Several years later the cones had sagged just about all the way down.
Cone sag is definitely NOT a myth. If you want down firing, consider the option of mounting the drivers in such a way that you can reverse them every one in a while.
Some many, many years ago I made a large coffee table with four down-firing CTS 12W19 Woofers - 12", heavy cone and a free air resonance of about 15Hz.
Several years later the cones had sagged just about all the way down.
Cone sag is definitely NOT a myth. If you want down firing, consider the option of mounting the drivers in such a way that you can reverse them every one in a while.
It`s inherent nature of low fs/high compliance drivers having somewhat "soft" suspension. It has nothing to do with qualtiy (what I presume You`re talking about) .
Avoiding "soft" suspensions with low fs-drivers means higher cone mass / lower compliance (stiffer) suspension - but that`s not always desirable and often comes along with other disadvantages (lower X-max).
I can only second this!!
pinkmouse said:
How do you figure that tight, transient bass translates into IM distortion or upper bass in the passband?!?!
What that translates to me is a well designed sealed enclosure with a good quality amp with a high damping factor to better control the cone movement.
Bill Fitzpatrick said:
One of my first home built subs about 10 years ago was a down-firing one with a 15" driver. My brother has now been using it for the past 8 years and it still works fine with no sag at all. Not to mention that it plays all the way down to 17Hz at about 105dB.
cocolino said:
My dipole subs use Pyle Pro 15" drivers with an Xmax of 6mm. Even at 20Hz, they play so loud that you can feel the concrete foundation vibrating in the other room! Each driver has a sensitivity of 90dB @ 1 watt and do not move much at all, but they definately reproduce the lowest of bass notes with no problems.
That cone sag thing is interesting, but it sounds like it would only be a problem with certain drivers. This Dayton has a very tight suspension to start with, and the cone is a fairly light paper pulp, which I wouldn't think would present a problem.
I am also curious about the "quick" sound of front firing subs and the possibility of IM distortion. I don't know the answer to that, but it reminds me of an article I read a few years ago that suggested that the tightness of bass starts in the midbass reigon, and that subwoofers may sound a bit slower and more rounded when they play by themselves because the upper frequncies that start each note are missing.
Things that make you go Hmmmmmmmmmmmmm.......
I am also curious about the "quick" sound of front firing subs and the possibility of IM distortion. I don't know the answer to that, but it reminds me of an article I read a few years ago that suggested that the tightness of bass starts in the midbass reigon, and that subwoofers may sound a bit slower and more rounded when they play by themselves because the upper frequncies that start each note are missing.
Things that make you go Hmmmmmmmmmmmmm.......
Heh... what if you mount the speaker horizontially anyway? It'd give a bit of a cavity in [front|behind] the speaker and take up more space but sag isn't a problem...
BTW I agree that it might be IMD, etc. on those "crisp" subs. I mean, how the heck can you call 20Hz crisp!?
Tim
BTW I agree that it might be IMD, etc. on those "crisp" subs. I mean, how the heck can you call 20Hz crisp!?
Tim
chops said:
I was simply going by your statement that the bass from your speaker sounds better if it is pointing directly at you.
This implies that something is lost if the speaker faces away from you, and that could only be high frequencies, because of there directionality, therefore your speaker is producing high frequencies .Q.E.D.
You can easily test this - just put a mic, (any old one will do) very close to the driver, display the results on a pc FFT program, and put pure sine waves through the driver. Then sweep the sine wave slowly up and down. I bet at some frequencies you will have more than one peak on the display, as every driver I have ever tested shows IMD somewhere in its frequency band. Since KelticWizard rekindled my interest in IM distortion a few months ago, I have been testing lots of stuff, and the results are eye opening to say the least!
People lose sleep at night trying to figure out if
they should go with plan A box design or plan B
box design, they burn their brain trying to find
justification for one design over another.
The simple solution to the madness is just to go
buy some cheapo 3/4" particle board and slap
together a box, get some nails, etc. It doesn't
have to be pretty. Two test boxes will easily
reveal each sonic signature, pick the one you like
and build the real box later. Peace of mind wins.
they should go with plan A box design or plan B
box design, they burn their brain trying to find
justification for one design over another.
The simple solution to the madness is just to go
buy some cheapo 3/4" particle board and slap
together a box, get some nails, etc. It doesn't
have to be pretty. Two test boxes will easily
reveal each sonic signature, pick the one you like
and build the real box later. Peace of mind wins.
I have a better idea, in this situation I just build a normal square sub and try it facing down and facing to the side, then just slap the feet on the appropriate side.
Saves trees.
Saves trees.
Hey - I've never seen an MDF tree 🙂
(sorry couldn't resist that dumb stab)
I'd like to see a very muscular driver, downfiring, with no feet on the box - with it's surround / driver edge hard against the floor "lifting the box" as it pumps at 20Hz - now that would be a freaky sight!
I suppose that would turn the other side of the box into the driver - now there is a thought.... must slap a patent on it 🙂
Ah, a mass driver 🙂 Great for that <50Hz rumble I'm sure...
Might also check out earthquake generators. Like the original that Tesla made... 😉
Tim
Might also check out earthquake generators. Like the original that Tesla made... 😉
Tim
Here's something to think about......
Look at all the different subs out on the market right now, including the built-in subs on tower speakers, and count how many you see that are side-firing subs vs. down-firing subs.
There must be a reason why more than 80% of the industry is going with side-firing subs these days.
And it's NOT for IM distortion or upper bass harmonics!
And all of you know exactly what I mean about "crisp" bass. I mean, if all of you desire nasty, sloppy, one-note bass, then so be it, but don't get on my case because I desire natural, realistic bass.
I would be willing to put my dipole subs up against anything any of you have and I bet mine would come out the best every time. And remember, I'm not some flunky that likes to run his mouth off either. I have bought, built, and listened to hundreds of different subs out there of all types, and my current dipoles blow all of them away!
Look at all the different subs out on the market right now, including the built-in subs on tower speakers, and count how many you see that are side-firing subs vs. down-firing subs.
There must be a reason why more than 80% of the industry is going with side-firing subs these days.
And it's NOT for IM distortion or upper bass harmonics!
And all of you know exactly what I mean about "crisp" bass. I mean, if all of you desire nasty, sloppy, one-note bass, then so be it, but don't get on my case because I desire natural, realistic bass.
I would be willing to put my dipole subs up against anything any of you have and I bet mine would come out the best every time. And remember, I'm not some flunky that likes to run his mouth off either. I have bought, built, and listened to hundreds of different subs out there of all types, and my current dipoles blow all of them away!
One reason there are more side facing subwoofers than down facing ones is that a downfacing one put on thick carpeting is likely to be signficantly muffled, unless the legs are pretty long, which then looks stupid or unstable. Given the public's penchant for choosing percieved value over actual worth, this would be a problem from the manufacturer's point of view. Who wants to buy a box with no visible driver, and one that looks stupid also?
Obviously I am not entirely in agreement with the 'if it sells well, it must be right' theory. Not to be insulting but would you follow this logic to the point of buying Bose?
Obviously I am not entirely in agreement with the 'if it sells well, it must be right' theory. Not to be insulting but would you follow this logic to the point of buying Bose?
Another point in favour of of down loaders ...
If the sub fires horizontally, you have to keep the cabinet still to avoid smearing and to get a clear, fast sound. This often means using spikes that couple the sub to the floor, resulting in floor vibration that can be clearly felt. Without spikes the effect of the cabinet movement can be even worse.
With a down-firing (or up-firing) sub there is no tendency for the cabinet to move in the horizontal plane as the cone vibrates. Gravity itself will minimize vertical movement. Therefore you can decouple the speaker from the floor (using rubber, superballs, inner tubes, etc.). This will result in a reduction of floor vibration and tighter bass. The 0.1% of us who have shag carpets may need to mount their down-firing speakers on marble slabs or similar.
One more thing ...
It doesn't matter one jot if 80% of all commercial subs are front-firing. Most manufacturers are like sheep. For example, on this forum we discuss various other issues such as internal standing waves and diffraction effects. What percentage of manufacturers take these into account at all?
Steve
If the sub fires horizontally, you have to keep the cabinet still to avoid smearing and to get a clear, fast sound. This often means using spikes that couple the sub to the floor, resulting in floor vibration that can be clearly felt. Without spikes the effect of the cabinet movement can be even worse.
With a down-firing (or up-firing) sub there is no tendency for the cabinet to move in the horizontal plane as the cone vibrates. Gravity itself will minimize vertical movement. Therefore you can decouple the speaker from the floor (using rubber, superballs, inner tubes, etc.). This will result in a reduction of floor vibration and tighter bass. The 0.1% of us who have shag carpets may need to mount their down-firing speakers on marble slabs or similar.
One more thing ...
It doesn't matter one jot if 80% of all commercial subs are front-firing. Most manufacturers are like sheep. For example, on this forum we discuss various other issues such as internal standing waves and diffraction effects. What percentage of manufacturers take these into account at all?
Steve
Re: Another point in favour of of down loaders ...
They aren't often downfiring because people wouldn't see the driver then.
dave
7V said:
They aren't often downfiring because people wouldn't see the driver then.
dave
The Carver AL-III's had downfiring subs, and they faired pretty well.
The "sag" idea has potential, but at the same time, if the magnet has enough control over the cone, its not gonna move much at all. And most paper/poly cones are rather light.
I also see it as being good because it inherently hides high freq junk that might get in there should your crossover not be the best.
The "sag" idea has potential, but at the same time, if the magnet has enough control over the cone, its not gonna move much at all. And most paper/poly cones are rather light.
I also see it as being good because it inherently hides high freq junk that might get in there should your crossover not be the best.
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