Turobodawd,
Just took a look your build again; now I remember it. I only read the first couple pages before, because I saw in your original goals that you were tuning to 38Hz and planned on using it outdoors. I didn't figure you were looking for the kind extension and goals I was. I'll have to go back through the whole thing.
Evan
Just took a look your build again; now I remember it. I only read the first couple pages before, because I saw in your original goals that you were tuning to 38Hz and planned on using it outdoors. I didn't figure you were looking for the kind extension and goals I was. I'll have to go back through the whole thing.
Evan
I was only looking at 4 ohm drivers as to get the most from whatever sub amp I go with. Is there any benefit to using an 8 ohm driver in this aplication?
Evan
That's up to you. Do your math.
RSS315HFA-8 12" - (Pmin.) 172.7 W@8 Ohms, (V) 33.38 V, SPL/1 m 106.7 dB(@max. elongation ± 14.30 mm).
RSS315HF-4 12" - (Pmin.) 169.2 W@4 Ohms, (V) 23.63 V, SPL/1 m 107.5 dB(@max. elongation ± 14.30 mm).
I will generally pick lower impedance drivers for subwoofers, provided the amplifier is stable.
I'm still on the hunt for a decent subwoofer amplifier that's 1 ohm stable :S
Yes, it's for a portable PA system, but it has sound quality comparable to a pretty good hi-fi, with much higher output than a typical home system. I get usable extension to 30hz in room, with excellent bass definition, impact and output. I was looking for higher output 35-50hz so mine is tuned higher than a normal home sub, but it wouldn't be much of a change to tune lower.
Just make sure that to do all you can to improve air flow inorder to minimize port compression - look at the port and bracing in my project.
From what I recall, the HF12 modeled very similarly to the HO15 in the same boxes/tuning. I went with the HO15 for 50% more displacement and better sensitivity....
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piston area wins every time
Agree 100%. Also, I want to clarify from an earlier post; YES, the factory spec Fs is listed as 24(ish). I was pleasantly surprised when my pair measured out at 21 (ish). I have not used my particular twin pair in quite some time, but I plan on installing a secondary/ HT system in the next few days using these things. As far as sound quality, what i meant was, for sub frequencies only (80&down), there's no valid reason I can think of to use the 12" Hf version over this unit. Plus, as the "dawg" mentions, you got yourself a pumpin 15" over a 12", it's almost twice as much cone (piston) area.
I'll look for my old construction notes from 2009 (i think?) and also give an updated report on their sound quality in a few days.
Agree 100%. Also, I want to clarify from an earlier post; YES, the factory spec Fs is listed as 24(ish). I was pleasantly surprised when my pair measured out at 21 (ish). I have not used my particular twin pair in quite some time, but I plan on installing a secondary/ HT system in the next few days using these things. As far as sound quality, what i meant was, for sub frequencies only (80&down), there's no valid reason I can think of to use the 12" Hf version over this unit. Plus, as the "dawg" mentions, you got yourself a pumpin 15" over a 12", it's almost twice as much cone (piston) area.
I'll look for my old construction notes from 2009 (i think?) and also give an updated report on their sound quality in a few days.
I went through the rest of your thread. Very nice build. They turned out a lot smaller, nicer looking than I was expecting for PA use.
I noticed you were very concerned with getting the port right, I assume it worked? I was thinking that the port opening was huge, I would have thought it would need to be a lot longer. I guess if I used a similar approach I might have issues with length since I would be tuning lower.
I like and usually use slot ports, but with this build I figured I would probably go with maybe two round ports so I could tune it differently by stuffing one or both.
I see what you're saying about the 15" over a 12". I would only be using it below 80Hz, I actually usually crossover a bit lower than that. I do want tuneful, non-plodding, low bass though, but I'm guessing from your and dawg's recommendations that if properly designed/built I'll be happy with the HO-15.
Any thoughts on the TC Sounds 12". They are supposed to be monsters and have high sound quality. Models very well in 3ft^3 or less. Seems like the HO-15 and the TC-12 take a good amount of power.
Evan
That's up to you. Do your math.
RSS315HFA-8 12" - (Pmin.) 172.7 W@8 Ohms, (V) 33.38 V, SPL/1 m 106.7 dB(@max. elongation ± 14.30 mm).
RSS315HF-4 12" - (Pmin.) 169.2 W@4 Ohms, (V) 23.63 V, SPL/1 m 107.5 dB(@max. elongation ± 14.30 mm).
Fair enough
I noticed that when I was modeling sealed alignments, they seemed to reach xmax with under 200W. I guess that just means I need less power, with the trade-off being I should expect less output? I don't listen at super high volumes, but I do like the ability when the mood strikes. Also, I don't want them to get damaged at decent movie watching levels. Maybe the acoustic suspension prevents this? I don't have any experience with sealed subs in a HT environment.
Evan
yea, but the epic 12 with it's monster 22mm xmax moves the same air as a 15" with 14mm xmax. And you will not be able to get a port big enough in it because the box is even smaller. But for a 20hz F3 using passive radiatiors (another $200), I'd use it in a house, definitely with it's smallish box. Or run it in car, sealed in a 1.5ft3 qtc=.707 with Fsb=F3=45hz. Should go flat to 10hz in that use.
What is the F3's we want here ?
I thought this was for pa ?
Many of these deep reaching drivers have under 85db spl 1w/1m, versus more pa-ish stuff with higher spl 1w/1m, but having F3's around 40hz. So 105db (with 100 watts) is low for pa subs. My buddy swears by 40hz F3's for PA. And subsonic protection. Ports are smaller also. Close to 115db with 100 watts for a single driver.
Just because a driver can take 400 watts rms doesn't mean you will be 6db louder than 100 watts. You are probably lucky to pick up 2.5db.........
Norman
What is the F3's we want here ?
I thought this was for pa ?
Many of these deep reaching drivers have under 85db spl 1w/1m, versus more pa-ish stuff with higher spl 1w/1m, but having F3's around 40hz. So 105db (with 100 watts) is low for pa subs. My buddy swears by 40hz F3's for PA. And subsonic protection. Ports are smaller also. Close to 115db with 100 watts for a single driver.
Just because a driver can take 400 watts rms doesn't mean you will be 6db louder than 100 watts. You are probably lucky to pick up 2.5db.........
Norman
Hey Norma,
I think you're confusing me with Turbodawg and his PA sub build. This is for home use, sound quality first, but with good extension. An f3 of 20 would be great, but I wouldn't care if it "only" went down to 25ish.
I don't want to go passive radiators. My current sub (Klipsch rsw-10d) uses a passive radiator. I'd like to be able to tune it by stuffing a port or two if desired.
About sensitivity/watts, I suppose you're talking about pro audio woofers? I'm looking more for a true subwoofer with sensitivity of 84-87db. I wouldn't mind a design that I can drive to decent levels with 250-300 watts. I did consider stripping the Klipsch sub of it's amp to get the digital controls (500W Bash). I really use them when switching from movies to music, but I'd like this sub to be equally good at both or giving up a bit on the HT end for sound quality for music.
Thanks for your thoughts on the TC. It sounds like, out of my list of possibles, the Dayton HO-15 is getting the props.
Evan
np.
Sound quality.
Push pull would be best, but that requires 2 drivers in a twice as big box.
I've found tuning to 27hz ( and a ported F3) to be excellent for sound quality.
I can stuff a port on my double 15 and it changes tuning from 40hz to around 27hz.
The sound went from thunk thunk (think bad dance music ) to boom, very deep and smooth. No going back to 40hz tuning, ever.
lol, the phase angle of a subwoofer 80hz filter induces a tremendous amount of delay but decreases as it goes lower in frequency. And your room will flex then reintroduce pressure slower than your sub starts and stops.
Everyone claims that sealed is "quicker".
I stuffed both ports of my 15's.
The bass was not "quicker".
It seemed 6db quieter.
You could put the 15" rss390hf in a 4ft3 box (120L).
I think the shallower roll-off of the sealed will make up for the higher F3 compared to a ported sub. And I think they need over 200 watts to skip past xmax, that'd be 107-110db, that's a lot. And a very easy box to build also.
If you have a 3ft3 box, you really will need a huge port due to the higher xmax drivers you are looking at. And as the diameter goes up, the length goes up. That's why a few of us are griping you'd need passive radiators. But that will be costly because although companies use 2x, ideally a pr moves 3x as much air. So a 14mm xmax 15" would need 2 x 20mm xmax 15" sized passive radiators.
For example, I had a pair of 18's that had a 12" port (16ft3, 27hz tuning). They were 4.3mm xmax. That's be equal to a pair of 12" 8mm xmax drivers, or a single 18" with 8.6mm xmax. Your 15" with 14mm xmax moves more air than my double 18's 4.3mm xmax did. But I have a huge box, so I could get away with the proper sized port.
I also had a pair of panel electrostats with 10" (sealed).
Yes they tapered off in the bass, but they seemed to go very low.
Not room shaking levels.
Keep us updated.
Norman
Sound quality.
Push pull would be best, but that requires 2 drivers in a twice as big box.
I've found tuning to 27hz ( and a ported F3) to be excellent for sound quality.
I can stuff a port on my double 15 and it changes tuning from 40hz to around 27hz.
The sound went from thunk thunk (think bad dance music ) to boom, very deep and smooth. No going back to 40hz tuning, ever.
lol, the phase angle of a subwoofer 80hz filter induces a tremendous amount of delay but decreases as it goes lower in frequency. And your room will flex then reintroduce pressure slower than your sub starts and stops.
Everyone claims that sealed is "quicker".
I stuffed both ports of my 15's.
The bass was not "quicker".
It seemed 6db quieter.
You could put the 15" rss390hf in a 4ft3 box (120L).
I think the shallower roll-off of the sealed will make up for the higher F3 compared to a ported sub. And I think they need over 200 watts to skip past xmax, that'd be 107-110db, that's a lot. And a very easy box to build also.
If you have a 3ft3 box, you really will need a huge port due to the higher xmax drivers you are looking at. And as the diameter goes up, the length goes up. That's why a few of us are griping you'd need passive radiators. But that will be costly because although companies use 2x, ideally a pr moves 3x as much air. So a 14mm xmax 15" would need 2 x 20mm xmax 15" sized passive radiators.
For example, I had a pair of 18's that had a 12" port (16ft3, 27hz tuning). They were 4.3mm xmax. That's be equal to a pair of 12" 8mm xmax drivers, or a single 18" with 8.6mm xmax. Your 15" with 14mm xmax moves more air than my double 18's 4.3mm xmax did. But I have a huge box, so I could get away with the proper sized port.
I also had a pair of panel electrostats with 10" (sealed).
Yes they tapered off in the bass, but they seemed to go very low.
Not room shaking levels.
Keep us updated.
Norman
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Norman, I'm a little confused about the port length. Winisd is showing 3ft^3 fb/25, 1 4" port 14" long, 2 4" ports 30" long. Is that 2 15" ports or 2 30". If it's 15" then that should be doable, 2 x 30" could be tough. I've always found Winisd to over estimate the port length needed. I usually multiply whatever they give by .7.
Also, I could easily go up to 3.5-3.75ft^3. Maybe as much as 4'.
Are you saying you like the Dayton HO-15" tuned to 27Hz or is that just a general tuning you like?
Evan
Also, I could easily go up to 3.5-3.75ft^3. Maybe as much as 4'.
Are you saying you like the Dayton HO-15" tuned to 27Hz or is that just a general tuning you like?
Evan
27hz is a good frequency to tune at, in general.
And the Ho seems like 4ft3 tunes nicely for it (25-27hz).
2 x 4" diameter ports 30" long is not enough (in my opinion) for that much xmax / cone area. I'd like to see a larger port, but now you see the port getting longer than the box.
At low volumes you may never notice a problem.
And yes, as the port size (diameter) goes up, the port length also increases.
That's why I usually go with 2 drivers in big 1 box, the port is shorter, but you want only 1 sub that isn't huge, so we'll stay on subject.
Then again, the snell ics sub 24 (double 12") has dual 4" ports (I think).
"Port noise was never audible when the main speakers were connected, and only barely audible when the sub was playing solo, and then only at the highest playback levels."
Way Down Deep III Snell ICS Sub24 | Home Theater
It's your money and your project.
4ft3
either the 390ho ported to 25hz (or 27, whatever)
or the 390hf in a sealed box.
Norman
And the Ho seems like 4ft3 tunes nicely for it (25-27hz).
2 x 4" diameter ports 30" long is not enough (in my opinion) for that much xmax / cone area. I'd like to see a larger port, but now you see the port getting longer than the box.
At low volumes you may never notice a problem.
And yes, as the port size (diameter) goes up, the port length also increases.
That's why I usually go with 2 drivers in big 1 box, the port is shorter, but you want only 1 sub that isn't huge, so we'll stay on subject.
Then again, the snell ics sub 24 (double 12") has dual 4" ports (I think).
"Port noise was never audible when the main speakers were connected, and only barely audible when the sub was playing solo, and then only at the highest playback levels."
Way Down Deep III Snell ICS Sub24 | Home Theater
It's your money and your project.
4ft3
either the 390ho ported to 25hz (or 27, whatever)
or the 390hf in a sealed box.
Norman
If you're looking for something with the TC Sounds drivers, take a look over here:
http://www.diyaudio.com/forums/subw...ded-transmission-line-od-ml-tl-design-bj.html
I'm just finishing up a pair with epic 12s instead of the Eminence 12.
http://www.diyaudio.com/forums/subw...ded-transmission-line-od-ml-tl-design-bj.html
I'm just finishing up a pair with epic 12s instead of the Eminence 12.
I went back and looked at the epic12 vs. the HO15, seems like they model very similarly and have very similar max output around tuning in my box model. Not sure why I passed over the epic in favor of the HO.....HO15 was about $70 cheaper for the pair and is obviously a bit more visually impressive due to the size, but the epic certainly would have been easier to package.
Well, what would you suggest? 2 x 4" seems big to me, but I've never built a ported subwoofer just sealed sub and ported speakers. Maybe a slot like Turbodawg's? I like the look of slots and they're a little easier to construct without needing extra parts. It seem to me though that if the slot for this woofer in a 3.5ft^3 enclosure had the surface area of his then it would need to be VERY long, too long for the box.
Evan
The Epic's were just a thought and they seemed to model just a well, but in a smaller enclosure. Also, very high output. If I remember correctly they had more output than the HO-15 at the same power input. And as Dawg says, probably easier to package.
That being said, I think I'm leaning towards the HO-15" Based on the recommendations here and the completely glowing reviews on PE.
That being said, I think I'm leaning towards the HO-15" Based on the recommendations here and the completely glowing reviews on PE.
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