So I have begun DIY sub project. I have ordered some parts including A DAYTON RSS315HF-4 12" HIGH FIDELITY SUBWOOFER (295-464) and a DAYTON SA240 240W SUBWOOFER AMPLIFIER (300-804 ) from Parts Express. Originally, I was going to use Dayton's 15" Quatro driver but that would have required a 6 cu.ft. box. The one I ordered is supposedly a higher end driver allowing for a smaller box one is (closer to a 4 cu.ft.) My plan is to build a box around 25"H x 18"W x 22"D with some simple bracing and a 4" flared port, locating the driver on the front of the box. I used some software to determine that this one models F3 around 21.15Hz which for my needs should be just dandy. The tech guy at Parts Express also suggested I "use as much damping (fill) as possible (without blocking the path from the rear of the woofer to the port). This will decrease group delay (boominess)". But, after adding more stuffing, the F3 jumps up to about 27hz! Now I don't know if my old ears can even hear 27hz, but I'm wondering if this is the right driver for the money. On the other hand, I'm still pretty close to my goal of spending around $200.00 for parts to build this thing.
My goals is to build a Sub that's not to big, sounds good for music and HT. I won't be playing at ear splitting volumes but pretty llou from time to time. If you had to configure these parts, what would you do? Would you use different parts keeping in mind the budget? Any other suggestions are welcome!!
Thanks,
Greg
Driver Specs:
Specifications: *Power handling: 400 watts RMS/700 watts max *VCdia: 2-1/2" *Le: .95 mH *Impedance: 4 ohms *Re: 3.3 ohms *Frequency range: 23 - 1,000 Hz *Fs: 23 Hz *SPL: 89 dB 2.83 V/1m *Vas: 3.00 cu. ft. *Qms: 3.00 *Qes: .52 *Qts: .44 *Xmax: 14mm *Dimensions: A: 12-3/8", B: 11-1/8", C: 5-3/8".
My goals is to build a Sub that's not to big, sounds good for music and HT. I won't be playing at ear splitting volumes but pretty llou from time to time. If you had to configure these parts, what would you do? Would you use different parts keeping in mind the budget? Any other suggestions are welcome!!
Thanks,
Greg
Driver Specs:
Specifications: *Power handling: 400 watts RMS/700 watts max *VCdia: 2-1/2" *Le: .95 mH *Impedance: 4 ohms *Re: 3.3 ohms *Frequency range: 23 - 1,000 Hz *Fs: 23 Hz *SPL: 89 dB 2.83 V/1m *Vas: 3.00 cu. ft. *Qms: 3.00 *Qes: .52 *Qts: .44 *Xmax: 14mm *Dimensions: A: 12-3/8", B: 11-1/8", C: 5-3/8".
I'm a new guy here, so you can take my reply for what it's worth, but since I just went through the same choices for my sub I'll throw in my 2 cents.
I went with the 15" Quattro in a ~2.5 ft^3 sealed box (16'"x 17.5" x 20" outside dimensions), and the 300 W BASH amp. I just got the thing running yesterday, and have spent a few hours doing setup and tuning this weekend.
WinISD models my box at f3 = 40 Hz, Qtc=.755. In that box the Quattro should handle about 200 W, good for over 110 dB. At that level, it won't botttom even at 10 Hz. With music having no content under 35 Hz, it will go even louder. I'll never hit it's limits!
In my irregularly shaped combined living room/dining room/entry hall (4400 ft^3, longest dimensions 25' x 24.5' x 9'), I'm seeing response pretty flat to 30 Hz. I couldn't really hear much from a 20 Hz warble tone, but all of the crystal in a hutch on the back wall of the DR started to rattle like a sustained earth quake. I don't think my room would want too much more bass!
The HF wants a much bigger box, vented or sealed. It really didn't look good in a sealed box. In a small box the Q was too high, in a big one the LF excursion is not controlled (limited power handling/SPL). In a vented box it goes a bit deeper than the sealed Quattro and would play a bit louder, but it's a lot bigger and a bit more expensive. Like any vented box, below cutoff the cone excursion is not controlled and needs a high-pass filter. Ultimate volume is limited by excursion at 109 dB @ 35 Hz.
None of that means you made a bad choice, the HF should play very low at non-OSHA approved levels! It's all about the compromises you want to make. For me, I took 4 dB less at 20 Hz in exchange for a smaller box, less $, more ultimate party SPL (not that I'll ever need it) and no fear of ever bottoming out the woofer. Plus that 15" woofer really makes a visual statement in the room! I'm glad my wife tolerates my obsessions!
I went with the 15" Quattro in a ~2.5 ft^3 sealed box (16'"x 17.5" x 20" outside dimensions), and the 300 W BASH amp. I just got the thing running yesterday, and have spent a few hours doing setup and tuning this weekend.
WinISD models my box at f3 = 40 Hz, Qtc=.755. In that box the Quattro should handle about 200 W, good for over 110 dB. At that level, it won't botttom even at 10 Hz. With music having no content under 35 Hz, it will go even louder. I'll never hit it's limits!
In my irregularly shaped combined living room/dining room/entry hall (4400 ft^3, longest dimensions 25' x 24.5' x 9'), I'm seeing response pretty flat to 30 Hz. I couldn't really hear much from a 20 Hz warble tone, but all of the crystal in a hutch on the back wall of the DR started to rattle like a sustained earth quake. I don't think my room would want too much more bass!
The HF wants a much bigger box, vented or sealed. It really didn't look good in a sealed box. In a small box the Q was too high, in a big one the LF excursion is not controlled (limited power handling/SPL). In a vented box it goes a bit deeper than the sealed Quattro and would play a bit louder, but it's a lot bigger and a bit more expensive. Like any vented box, below cutoff the cone excursion is not controlled and needs a high-pass filter. Ultimate volume is limited by excursion at 109 dB @ 35 Hz.
None of that means you made a bad choice, the HF should play very low at non-OSHA approved levels! It's all about the compromises you want to make. For me, I took 4 dB less at 20 Hz in exchange for a smaller box, less $, more ultimate party SPL (not that I'll ever need it) and no fear of ever bottoming out the woofer. Plus that 15" woofer really makes a visual statement in the room! I'm glad my wife tolerates my obsessions!
Read this, might find it interesting :
http://web.archive.org/web/20020808224043/integra.cyberglobe.net/caraudio/resources/fiberfill/
http://web.archive.org/web/20020808224043/integra.cyberglobe.net/caraudio/resources/fiberfill/
Good info. One reason I'm asking people to look at my numbers is that with bass Box Pro I'm getting this with the HF driver:
--Description--
Name:
Type: Vented Box
Shape: Prism, square (optimum)
--Box Parameters--
Vb = 3.239 cu.ft
V(total) = 3.487 cu.ft
Fb = 19.99 Hz
QL = 6.488
F3 = 23.44 Hz
Fill = normal
--Vents--
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 22.2 in
And from the 15" Quatro in a vented enclosure I'm getting:
Box Properties
--Description--
Name:
Type: Vented Box
Shape: Prism, square (optimum)
--Box Parameters--
Vb = 5.484 cu.ft
V(total) = 5.711 cu.ft
Fb = 19.25 Hz
QL = 5.98
F3 = 27.91 Hz
Fill = none
--Vents--
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 14.03 in
A
B
C
--External Dimensions--
A = 36.21 in
B = 22.95 in
C = 15.51 in
--Internal Dimensions--
A = 34.71 in
B = 21.45 in
C = 13.26 in
--Wall Thickness--
Front = 1.5 in
Side = 0.75 in
Driver Properties
--Description--
Name: 295-560 (published)
--Configuration--
No. of Drivers = 1
--Driver Parameters--
Fs = 21 Hz
Qms = 14
Vas = 6.6 cu.ft
Xmax = 0.394 in
Sd = 126.1 sq.in
Qes = 0.42
Re = 3.45 ohms
Le = 3.5 mH
Z = 4 ohms
Pe = 300 watts
I'm still not 100% on how to inteperate these specs (but I'm learning). But in vented boxes, they look pretty close except the HF shows a smaller box and better vent contol (I think)
--Description--
Name:
Type: Vented Box
Shape: Prism, square (optimum)
--Box Parameters--
Vb = 3.239 cu.ft
V(total) = 3.487 cu.ft
Fb = 19.99 Hz
QL = 6.488
F3 = 23.44 Hz
Fill = normal
--Vents--
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 22.2 in
And from the 15" Quatro in a vented enclosure I'm getting:
Box Properties
--Description--
Name:
Type: Vented Box
Shape: Prism, square (optimum)
--Box Parameters--
Vb = 5.484 cu.ft
V(total) = 5.711 cu.ft
Fb = 19.25 Hz
QL = 5.98
F3 = 27.91 Hz
Fill = none
--Vents--
No. of Vents = 1
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 14.03 in
A
B
C
--External Dimensions--
A = 36.21 in
B = 22.95 in
C = 15.51 in
--Internal Dimensions--
A = 34.71 in
B = 21.45 in
C = 13.26 in
--Wall Thickness--
Front = 1.5 in
Side = 0.75 in
Driver Properties
--Description--
Name: 295-560 (published)
--Configuration--
No. of Drivers = 1
--Driver Parameters--
Fs = 21 Hz
Qms = 14
Vas = 6.6 cu.ft
Xmax = 0.394 in
Sd = 126.1 sq.in
Qes = 0.42
Re = 3.45 ohms
Le = 3.5 mH
Z = 4 ohms
Pe = 300 watts
I'm still not 100% on how to inteperate these specs (but I'm learning). But in vented boxes, they look pretty close except the HF shows a smaller box and better vent contol (I think)
lousymusician said:
My apologies - I had a bad entry for the Vas of the HF in Win ISD. 
The overall curves do look very similar now. Both subs could probably use some filtering to prevent over-excursion and chuffing below 20 Hz, but that's pretty much a given with a vented woofer.
Now that I have established my lack of credibility, I'd guess your sub will come out just fine!
The overall curves do look very similar now. Both subs could probably use some filtering to prevent over-excursion and chuffing below 20 Hz, but that's pretty much a given with a vented woofer.Now that I have established my lack of credibility, I'd guess your sub will come out just fine!
Ah, I feel better now. Also simon5's post had some very interesting stuff (no pun intended). Apparently overstuffing the cabinet can lower the f3. The link that describes this wacky concepthttp://web.archive.org/web/20020808224043/integra.cyberglobe.net/caraudio/resources/fiberfill/ was working today but now seems to be broken.
lousymusician said:My apologies - I had a bad entry for the Vas of the HF in Win ISD.
Now that I have established my lack of credibility, I'd guess your sub will come out just fine!
I think people haven't gotten a little carried away with the use of WinISD and Bassbox, etc. They rely so heavily on how subs model in these programs, and make such a big deal about making them look in a free air theoretical model what they want in their room. My understanding is that you dont want a sub that measures flat to 20hz free air or it will have too much energy in that area in a room, because of room gain. Most Subs I have seen designed by proffessionals, in both real and kit form show an FS that is much higher than what most people are desiging around here, and I was told that was quite intentional.
I can say my own recent project, using this subwoofer in a 2 cubic foot box, which gave me a very high fs of about 37hz or so, with a little eqing, which I first modeled and later measured to get the numbers right, and now I have a response that is flat to below 20hz. I can hear something with 20hz warble tones, whether its the fundamental I can't say. Without the eq I still get an F10 of 20hz or so.
As for the excursion issue, yes it is known that subs will exceed excursion, given too much power, below the tuning frequency. However, generally this tuning frequency is low enough as not to be a big issue. Most ported speakers are not designed with a highpass filter in the low end, but dont see this over excursion very often. I wouldn't worry about it, if anything, even with an active filter, I would be more concerned with the effect the filter will have on the phase response. Look at how a sub models with a high and low pass filter, and just to really screw things up, try throwing some eq into the mix, see how that looks.
I can say my own recent project, using this subwoofer in a 2 cubic foot box, which gave me a very high fs of about 37hz or so, with a little eqing, which I first modeled and later measured to get the numbers right, and now I have a response that is flat to below 20hz. I can hear something with 20hz warble tones, whether its the fundamental I can't say. Without the eq I still get an F10 of 20hz or so.
As for the excursion issue, yes it is known that subs will exceed excursion, given too much power, below the tuning frequency. However, generally this tuning frequency is low enough as not to be a big issue. Most ported speakers are not designed with a highpass filter in the low end, but dont see this over excursion very often. I wouldn't worry about it, if anything, even with an active filter, I would be more concerned with the effect the filter will have on the phase response. Look at how a sub models with a high and low pass filter, and just to really screw things up, try throwing some eq into the mix, see how that looks.
pjpoes said:
Face it, WinISD is a pretty fun toy!
The last time I built a speaker, a hand calculator was the height of technology. This is much more entertaining, and I understand the tradeoffs in my choices much better for having the easy simulation tool.I much agree with your basic point that it's too easy to get caught up in chasing numbers. I designed for an F3 of 40 Hz, counted on room gain to fill in below that, and it seems I got what I expected.
My concerns about headroom and excursion are basically about conservative design. I want a system that will handle ludicrous movie soundtrack infrasonics or accidental abuse gracefully. I don't have the freedom to design fancy limiting circuitry into my amp, so I tried to choose a woofer, a sealed box and an amp that had similar performance envelopes. To me, a design that would allow the driver to bottom too easily is out of balance. Since I have to live with my compromises, I chose what I'm comfortable with. If the same conservative approach means low group delay, so much the better.
yeah I basically agree with that. I mostly build sealed subs as I feel they generally sound better. I will gladly give up a little low end response in favor of the tighter cleaner sounding bass I get with sealed setups. My current sub sounds far more natural in a sealed box than it did in a ported box, when playing music like Stand up Bass' or drums. Less overhang, for lack of a better word. It also made less 'bad' noises durring really loud movie soundtracks, something I just couldn't fix with a ported box. I remain a sealed box fan for subs at the moment. I'm sure if I built a large enough ported sub in a large enough box, I could manage these issues, but I wasn't willing to build a sub with a 15" woofer in an 8 cubic foot box with a 4" tall rectangular port.
My point is people get so caught up with numbers they think they are designing a better sub getting the flatest modeled response, forgetting about things like room interaction. They forget that adding a lot of eq can cause the woofer to reach max excursion quicker. That lots of filters can throw off the group delay and phase response. Ported subs generally dont have a great phase response anyway, but throw in a filter at 18hz and 80hz, or something like that, and you have a terrible phase response.
My point is people get so caught up with numbers they think they are designing a better sub getting the flatest modeled response, forgetting about things like room interaction. They forget that adding a lot of eq can cause the woofer to reach max excursion quicker. That lots of filters can throw off the group delay and phase response. Ported subs generally dont have a great phase response anyway, but throw in a filter at 18hz and 80hz, or something like that, and you have a terrible phase response.
I agree with you that we shouldn't design flat in simulation programs to take into account the room.
That doesn't render WinISD Pro useless !!! We can take into account room gain in the program.
I use it with my ~ +3 dB per octave room gain in my head.
So I design the ported sub to be 0 dB at 80 Hz, -3 dB at 40 Hz, -6 dB at 20 Hz, -9 dB at 10 Hz.
Some other use it with a parametric EQ to simulate room gain, then remove it when they check the excursion graphs and else.
That doesn't render WinISD Pro useless !!! We can take into account room gain in the program.
I use it with my ~ +3 dB per octave room gain in my head.
So I design the ported sub to be 0 dB at 80 Hz, -3 dB at 40 Hz, -6 dB at 20 Hz, -9 dB at 10 Hz.
Some other use it with a parametric EQ to simulate room gain, then remove it when they check the excursion graphs and else.
Well I'm bouncing around between diifferent points of view on the design and execution of this subwoofer project. Some say overstuff the box, and some say don't put any fiberfill in the box! So I thought I would appeal to this bbs with some specific questions. I'm also guilty of with fiddling with some software packages (sorry pjpoes) simply to establish a baseline. I'm also trying to learn enough through reading, forums, etc. to come up with a design. I'm on the front end of the learning curve here but ultimately I want build the darn thing and soon! Since I'm certain my first try ain't going to be perfect, I have a few other resources to help tweak the sound:
1. My Yamaha RX-V2500 has a pretty good auto-setup parametric EQ.
2. There's tweakabilty in a DIY subwoofer
3. I've had years of exposure to some good stuff including B&W Mtrx 801, Martin Logan, Quad, Bryston, etc. (sadly, I could never afford it!). I have some perspective and trust my ears to fine tune things
4. My current setup is fairly humble (thousand dollar speakers, thousand dollar receiver, source music is mostly off the computer) so and I don't expect it to reveal flaws like some of the higher end stuff will.
MY QUESTIONS:
1. WinISD shows a group delay over 27 ms. Some think group delay is over hyped. 27ms seems like a lot. What can I expect from that figure. How audible is it at the lower frequencies. (no way I can hear 20hz anyway)
2. What do you think about the box size?
3. The parts that I ordered are the Dayton RSS315HF-4 12" Woofer (295-464) and their SA240 Plate Map (300-804) Do these parts look okay for this design?
4. Stuff the box, don't stuff; how about bracing. Any other construction advice?
Below, I've listed specific data from WinISD.
For the driver in an unstuffed box, WinISD suggests the following:
Number of drivers : 1
Box type : Vented
Box size : 2.917 ft^3
Tuning frequency : 23.20 Hz
Vent : 1 vent(s)
18.42 in length for each
4.02 in round
I've attached some graphs n' charts from WinISD which might help. The parts are coming today so I'm hoping you're not going to say "those parts won't work you idiot". Also, I'm not expecting flat down to 20 hz. I don't need the bass to interfere with my breathing. I'm not trying for concert volume levels; just a clean rich bottom end to augment my reasonably full (down to about 35hz) front speakers.
Thank You!
Greg
Some Specs:
Driver spec:
Driver : 295-464 dAYTON rss hf
Vas : 3.000
Qts : 0.40
Fs : 23.00
SPL : 89.00
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -6.10 82.90
25.00 -1.61 87.39
30.00 -0.37 88.63
35.00 -0.13 88.87
40.00 -0.08 88.92
45.00 -0.08 88.92
50.00 -0.07 88.93
55.00 -0.07 88.93
60.00 -0.07 88.93
65.00 -0.06 88.94
70.00 -0.06 88.94
75.00 -0.05 88.95
80.00 -0.05 88.95
85.00 -0.04 88.96
90.00 -0.04 88.96
95.00 -0.04 88.96
100.00 -0.03 88.97
Previously posted on another BBS regarding a fully stuffed enclosure:
1. My Yamaha RX-V2500 has a pretty good auto-setup parametric EQ.
2. There's tweakabilty in a DIY subwoofer
3. I've had years of exposure to some good stuff including B&W Mtrx 801, Martin Logan, Quad, Bryston, etc. (sadly, I could never afford it!). I have some perspective and trust my ears to fine tune things
4. My current setup is fairly humble (thousand dollar speakers, thousand dollar receiver, source music is mostly off the computer) so and I don't expect it to reveal flaws like some of the higher end stuff will.
MY QUESTIONS:
1. WinISD shows a group delay over 27 ms. Some think group delay is over hyped. 27ms seems like a lot. What can I expect from that figure. How audible is it at the lower frequencies. (no way I can hear 20hz anyway)
2. What do you think about the box size?
3. The parts that I ordered are the Dayton RSS315HF-4 12" Woofer (295-464) and their SA240 Plate Map (300-804) Do these parts look okay for this design?
4. Stuff the box, don't stuff; how about bracing. Any other construction advice?
Below, I've listed specific data from WinISD.
For the driver in an unstuffed box, WinISD suggests the following:
Number of drivers : 1
Box type : Vented
Box size : 2.917 ft^3
Tuning frequency : 23.20 Hz
Vent : 1 vent(s)
18.42 in length for each
4.02 in round
I've attached some graphs n' charts from WinISD which might help. The parts are coming today so I'm hoping you're not going to say "those parts won't work you idiot". Also, I'm not expecting flat down to 20 hz. I don't need the bass to interfere with my breathing. I'm not trying for concert volume levels; just a clean rich bottom end to augment my reasonably full (down to about 35hz) front speakers.
Thank You!
Greg
Some Specs:
Driver spec:
Driver : 295-464 dAYTON rss hf
Vas : 3.000
Qts : 0.40
Fs : 23.00
SPL : 89.00
Relative
Freq Gain SPL
[Hz] [dB] [dB]
20.00 -6.10 82.90
25.00 -1.61 87.39
30.00 -0.37 88.63
35.00 -0.13 88.87
40.00 -0.08 88.92
45.00 -0.08 88.92
50.00 -0.07 88.93
55.00 -0.07 88.93
60.00 -0.07 88.93
65.00 -0.06 88.94
70.00 -0.06 88.94
75.00 -0.05 88.95
80.00 -0.05 88.95
85.00 -0.04 88.96
90.00 -0.04 88.96
95.00 -0.04 88.96
100.00 -0.03 88.97
Previously posted on another BBS regarding a fully stuffed enclosure:
Chris doesn't believe in a test done by Tom Nousaine ? His credibility goes down the drain if it's the case... Did you point him to the article?
Anyway, about stuffing, it's easy. You add it, don't like it? Remove it. I was talking about 1 lb per cu.ft, that's not extreme stuffing. It's a bit hard to exactly predict the effect of stuffing, so I didn't use it in my first project but I'll definitely use it in my next project to see if it's good for me or not.
1. 27ms at 20 Hz of group delay? Perfectly acceptable, Chris is right on this.
2. 3 cu.ft is ok, but if you can go larger, you could go lower.
3. Parts are perfect.
4. Stuff or not, your choice. Good bracing is important. Here's an example :
Anyway, about stuffing, it's easy. You add it, don't like it? Remove it. I was talking about 1 lb per cu.ft, that's not extreme stuffing. It's a bit hard to exactly predict the effect of stuffing, so I didn't use it in my first project but I'll definitely use it in my next project to see if it's good for me or not.
1. 27ms at 20 Hz of group delay? Perfectly acceptable, Chris is right on this.
2. 3 cu.ft is ok, but if you can go larger, you could go lower.
3. Parts are perfect.
4. Stuff or not, your choice. Good bracing is important. Here's an example :
An externally hosted image should be here but it was not working when we last tested it.
Ack! This should be my last question
It's me again,
I need a couple rules of thumb to work with here, and than I can start building.
I think I have the box figured out, with an F3 around 23.33 HZ and an FB about 18.6 but I think I've heard that there's a formula with respect to how these 2 relate.
Assuming that I've got the driver and box VB resolved, what are the other critical, relevant calculations that I need to consider? I've heard something about the F3 in relation to the FB; that one should be higher or lower, or something... Please advise.
Thanks,
Greg
__________________
It's me again,
I need a couple rules of thumb to work with here, and than I can start building.
I think I have the box figured out, with an F3 around 23.33 HZ and an FB about 18.6 but I think I've heard that there's a formula with respect to how these 2 relate.
Assuming that I've got the driver and box VB resolved, what are the other critical, relevant calculations that I need to consider? I've heard something about the F3 in relation to the FB; that one should be higher or lower, or something... Please advise.
Thanks,
Greg
__________________
Re: Re: specs attaced
Bassbox Pro from www.ht-audio.com and Win ISD from http://www.linearteam.dk/. Bass box costs money but does more (like printouts). WinISD asks for a donation so it's kind of freeware. I have no idea what I'm doing with either one of them!
vetkilr said:
Bassbox Pro from www.ht-audio.com and Win ISD from http://www.linearteam.dk/. Bass box costs money but does more (like printouts). WinISD asks for a donation so it's kind of freeware. I have no idea what I'm doing with either one of them!
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