My dwarf ported Dayton HF in a sono

[MCFuryNZ]

Greetings All

My requirements:
short, fat ported subwoofer in a sonotube as sort of a nightstand or table
low cost
better than my Velo DPS-10
Parts Express parts (I live nearby and am going up there to spend way too much money)
70/30 music/ht

What i've come up with is:
24" diameter sonotube @ 26" high for 143L
Tuned to 20hz with a 4" port 14.5" long
Dayton Reference HF 12" woofer
Dayton 240W amp

I've attached the graphs from UniBox.... everything looks ok. Seems to be getting the most from the Xmax, port airspeed is just within limits, I really don't know why it wouldn't work and sound pretty good, but as this is my first design I really don't know what to look for.

EDIT: oops I just realized I had it on 200W, but its pretty much the same as 240W as you might assume, and I doubt i'd come across that too often. Just let me know if it would be helpful to see the higher power.

What do you guys think? I know the amp has a 2nd order highpass at 18hz so that causes a bit of rolloff at the end, which I hope will be picked up slightly by room gain, but it's all experimentation at that point.

Thanks

[strossos]

Looks good, but I've heard that it won't get as loud as most people would like it to be. Maybe someone else has heard a similar setup on here that can let you know.

[JonMarsh]

Greetings All

My requirements:
short, fat ported subwoofer in a sonotube as sort of a nightstand or table
low cost
better than my Velo DPS-10
Parts Express parts (I live nearby and am going up there to spend way too much money)
70/30 music/ht

What i've come up with is:
24" diameter sonotube @ 26" high for 143L
Tuned to 20hz with a 4" port 14.5" long
Dayton Reference HF 12" woofer
Dayton 240W amp

I've attached the graphs from UniBox.... everything looks ok. Seems to be getting the most from the Xmax, port airspeed is just within limits, I really don't know why it wouldn't work and sound pretty good, but as this is my first design I really don't know what to look for.

EDIT: oops I just realized I had it on 200W, but its pretty much the same as 240W as you might assume, and I doubt i'd come across that too often. Just let me know if it would be helpful to see the higher power.

What do you guys think? I know the amp has a 2nd order highpass at 18hz so that causes a bit of rolloff at the end, which I hope will be picked up slightly by room gain, but it's all experimentation at that point.

Thanks

Looks pretty reasonable, port velocity is a bit high, I'd suggest two ports of that diameter (4") you do realize that 140 liters is a pretty good sized enclosure? This is sort of an EBS alignment. With as sharp a roll off as it has, it will unload quickly. Are you sure the net internal volume with driver installed will be that size and height sonotube? It sounds a little small to me... we're talking 5 cu ft. With the dimensions you give, assuming an interior volume diamter of 23", and interior height after endcaps of 24", I get a net volume of 3543 cu. in, which works out to 2 cu. feet. You need 2.5X more for 143 liters, unless I can't do math today (always possible). :W

[MCFuryNZ]

Looks pretty reasonable, port velocity is a bit high, I'd suggest two ports of that diameter (4") you do realize that 140 liters is a pretty good sized enclosure? This is sort of an EBS alignment. With as sharp a roll off as it has, it will unload quickly. Are you sure the net internal volume with driver installed will be that size and height sonotube? It sounds a little small to me... we're talking 5 cu ft. With the dimensions you give, assuming an interior volume diamter of 23", and interior height after endcaps of 24", I get a net volume of 3543 cu. in, which works out to 2 cu. feet. You need 2.5X more for 143 liters, unless I can't do math today (always possible). :W

Unless I'm missing something immensely important (definitely possible), I'm not getting that volume.... I do see what you mean about the quick unloading on the xmax graph and my sharp rolloff, but I have no idea how to counter that reasonbly.

Thanks

[sprint_9]

Ive got a Dayton 12 inch HF and a 240w amp in a slot ported box tuned to 19 hz with around 4.4 cuft with everything installed. I does do great for movies but lacks the punch that I like for my music, but I like alot of kick in my music when the bass hits.

[Landroval]

I'm getting internal volume of 163 liters with internal height of 24 inch and internal diameter of 23 inch so I guess the original calculations are ok.

[strossos]

Ive got a Dayton 12 inch HF and a 240w amp in a slot ported box tuned to 19 hz with around 4.4 cuft with everything installed. I does do great for movies but lacks the punch that I like for my music, but I like alot of kick in my music when the bass hits.

What mains do you have? Most of the chest impact comes from 80-120hz in music, thus the mains could be responsible for a bit of that lack.

[---k---]

but I like alot of kick in my music when the bass hits.

I'm guessing you do not like a flat response then. That's okay. It just isn't right. :W

[MCFuryNZ]

I'm guessing you do not like a flat response then. That's okay. It just isn't right. :W

So is this saying my setup looks ok? :lol:

The airspeed and xmax are just in spec and I feel like it would be getting the most out of this driver, as long as the harsh dropoff isnt an issue. Gotta keep in mind that's going to have the 240W amp's rumble filter at 18hz as well, so maybe i'll be ok.


Thanks guys

[---k---]

I think your graph looks fine and your math looks fine to me too. By that, I just called Jon wrong, so you better double check.

[sprint_9]

Yea the mains I have stink, which is why Im on here alot trying to decide on what to do for an upgrade. Right now I have Polk RT600i's and they really lack, I dont know what the deal is if its my reciever or the speakers but they lack. They sounded good at the local stealer but I have a feeling they were dumping alot of power to them, which I have not tried and would like to with a Behringer A500.

I have the same components that you will be building with and I can say that they are very nice quality and you will be pleased with the amp and sub. Also if I had a good quality amp or good mains for my speakers Im sure I wouldnt have any problems with my setup at all, it is very nice clean deep bass.

[soho54]

MCFuryNZ, I'm getting different numbers.

Sono is marked by internal diameter. So using a 24 x 26 piece, a 4" port tuned to 20Hz, an RS 12", and normal 3-layer 3/4" endcap construction I would say you are looking at ~165l. Port length from the top of the endcap to intake is 12" w/flare.

Minor differences I know.

With the amps HP this sub is going to brick wall ~20Hz. This isn't a problem unless you want more lower output. The port velocity is right at the limit, but should be fine with a peak around 20m/s at the 105dB levels.

[MCFuryNZ]

Yea the mains I have stink, which is why Im on here alot trying to decide on what to do for an upgrade. Right now I have Polk RT600i's and they really lack, I dont know what the deal is if its my reciever or the speakers but they lack. They sounded good at the local stealer but I have a feeling they were dumping alot of power to them, which I have not tried and would like to with a Behringer A500.

I have the same components that you will be building with and I can say that they are very nice quality and you will be pleased with the amp and sub. Also if I had a good quality amp or good mains for my speakers Im sure I wouldnt have any problems with my setup at all, it is very nice clean deep bass.

Unless your receiver is trash, it could be speaker placement. Those speakers look pretty nice and probably get to 50hz with some authority, but the reviews said its definitely clean and tight bass, so perhaps not exactly what you are looking for. Try the speakers in different placements, perhaps closer to a wall.

[MCFuryNZ]

MCFuryNZ, I'm getting different numbers.

Sono is marked by internal diameter. So using a 24 x 26 piece, a 4" port tuned to 20Hz, an RS 12", and normal 3-layer 3/4" endcap construction I would say you are looking at ~165l. Port length from the top of the endcap to intake is 12" w/flare.

Minor differences I know.

With the amps HP this sub is going to brick wall ~20Hz. This isn't a problem unless you want more lower output. The port velocity is right at the limit, but should be fine with a peak around 20m/s at the 105dB levels.

Hmmm, I'm new at this and was just plugging stuff into sonosub. I didn't realize sono was by internal diameter, but thats not where most of my fault lies... For sonosub.exe I have 144 "effective liters" with 24" x 25" (oops, not 26) endcap to endcap, 20.3hz tune, 4"x14" port. And I just realized that this is including the dayton reference 12" data provided by sonosub.

I do realize I'm going to be crapping out below 20hz but I feel like for the sake of the driver and my needs (mostly music, but not all), I'll keep that 18hz HP on the amp, unless I have good reason to change it (a good reason does not involve this forum's need for being flat to 15hz)

Thanks again,
Max C.

[soho54]

I was just mainly trying to confirm your overall design, while noting a discrepancy. Not trying to get you to change it. You had asked about the "harsh dropoff" being an issue before.

Sonosub is a great program. I had forgotten all about it. The only tricky part is setting up the endcap data, and that isn't hard.

Good luck. :T

[MCFuryNZ]

I was just mainly trying to confirm your overall design, while noting a discrepancy. Not trying to get you to change it. You had asked about the "harsh dropoff" being an issue before.

Sonosub is a great program. I had forgotten all about it. The only tricky part is setting up the endcap data, and that isn't hard.

Good luck. :T

Haha yeah i'm just messing around. I came in here thoroughly expecting to see 10 suggestions for a 6' sono with a 15" woofer. :

I am still concerned about the dropoff however, but it seems unavoidable already being at my box size limit, driver limits, and rumble filter. Definitely let me know if i'm way off base here.

Thanks for the help

[soho54]

6' nah, you want two 7 1/2 foot'ers like me. :B

Really though, the roll off is pretty much the same with any ported sub, typically 18- 24dB/octave. Unless you use an abnormally small box with a port sticking way out of it, like a small potbelly stove. The only reason Jon brought the roll off up is because without a highpass most modern movies sound tracks would kill the sub fast.

If you are sure about that 2nd order HP at 18Hz you will be fine in this regard. A 1st order from 18Hz or higher would do it also. As long as you have this protection the roll off is a non-issue.

[MCFuryNZ]

6' nah, you want two 7 1/2 foot'ers like me. :B

Really though, the roll off is pretty much the same with any ported sub, typically 18- 24dB/octave. Unless you use an abnormally small box with a port sticking way out of it, like a small potbelly stove. The only reason Jon brought the roll off up is because without a highpass most modern movies sound tracks would kill the sub fast.

If you are sure about that 2nd order HP at 18Hz you will be fine in this regard. A 1st order from 18Hz or higher would do it also. As long as you have this protection the roll off is a non-issue.

I sent an email to PE and they confirmed there's a highpass at 18hz... i've also searched quite a bit and have confirmed that in a few places, including the review PDF on the PE website. As a last resort i'll talk to the techs at PE when I DRIVE UP THERE TOMORROW! ;x(


Hooray for living in Cincinnati


This sub is going to come alive, thanks to you guys

[sprint_9]

Unless your receiver is trash, it could be speaker placement. Those speakers look pretty nice and probably get to 50hz with some authority, but the reviews said its definitely clean and tight bass, so perhaps not exactly what you are looking for. Try the speakers in different placements, perhaps closer to a wall.

Yea its likely one of the two there, I never really liked this reciever and may have to upgrade to a new 605, but will try different locals which will be easy since Im moving next week. The fact that the review said clean tight bass has me excited since thats what I like.

Anyhow enough with my mess and back to building a sub, Im excited to see how this comes out as Im not overly satisfied with my box and have pondered a smaller sized sono for it.

[Paul Ebert]

Really though, the roll off is pretty much the same with any ported sub, typically 18- 24dB/octave. Unless you use an abnormally small box with a port sticking way out of it, like a small potbelly stove. The only reason Jon brought the roll off up is because without a highpass most modern movies sound tracks would kill the sub fast.

Well, there is the issue of transient response, which will be degraded with this tuning compared to a more gradual rolloff. Guess it depends on what you want - flat response down low or transient accuracy.

Is the Velo servo controlled? If so, you may find this design is not a SQ improvement. Just something to think about...

With this much volume to work with, why not go with a RSS390HF? Not that much more $.

[soho54]

The Velo DPS-10 is a non-servo DSP vented design. Here's the response, for the OP's review. Taken outside at ~2 meters.

Well, there is the issue of transient response, which will be degraded with this tuning compared to a more gradual rolloff.

It is a given that TR in a vented design is not as good around the tuning frequency as a sealed sub.
EDIT: I think you could have been talking about vented designs with a lower corner Q, and not sealed enclosures. In that case I can see what you are saying, but to lower the Q you have to reduce the enclosure volume. Then the port has nowhere to go, and you end up with a potbelly stove. Of course when you add the LP back into the picture GD is higher at >30Hz in the softer Q box, and peak delay (while at a lower Hz) is higher.

Guess it depends on what you want - flat response down low or transient accuracy.

You can archive both in a vented (lots of space) or sealed (lots of watts/xmax) design.

It is also a little known fact that the Lowpass crossover used on the sub has an effect on TR as well. An 80Hz LP can make some sealed designs have worse response in the 30-80Hz range than a similar vented design. It's all give and take.

The RSS390HF would be nice, but sagging could be an issue in the long run. I've had mine for over a year, and they are still fine though. I have got to figure out a way to check for actual sagging. I'm pretty sure I have lost a couple mm. One day I'll get bored and figure it out. :B