After a long search I could not find a 15" or 18" woofer with parameters am I looking for:
High Qms (over 20)
High BL
High Vas
Low Mms
Low Fs (under 30hz)
Low inductance
This is going to be a multiple driver 8-12 vented or T/L subwoofer for impactful, dynamic bass at very low listening levels.
My question:
I found a driver that is close but Fs is too high and Vas is too small
Ciare 15NDH-3 - Ciare 15NDH-3 is a 15" lightweight neodymium speaker for all midrange and mid-bass speaker systems- Ciare Speakers - Ciare 15NDH-3 15" lighweight neodymium speaker for midrange and mid-bass speaker systems. Ciare 15NDH-3 15" bass spea
WITHOUT adding moving mass, what can I do to lower the Fs on this driver?
Change or cut the spider? Soften the spider?
Anyone had experience with such a situation?
High Qms (over 20)
High BL
High Vas
Low Mms
Low Fs (under 30hz)
Low inductance
This is going to be a multiple driver 8-12 vented or T/L subwoofer for impactful, dynamic bass at very low listening levels.
My question:
I found a driver that is close but Fs is too high and Vas is too small
Ciare 15NDH-3 - Ciare 15NDH-3 is a 15" lightweight neodymium speaker for all midrange and mid-bass speaker systems- Ciare Speakers - Ciare 15NDH-3 15" lighweight neodymium speaker for midrange and mid-bass speaker systems. Ciare 15NDH-3 15" bass spea
WITHOUT adding moving mass, what can I do to lower the Fs on this driver?
Change or cut the spider? Soften the spider?
Anyone had experience with such a situation?
the 15" drivers on this page come close, but Qms is lower;
etone PROFESSIONAL SOUND
methinks your cabinets are going to be about the size of a bus....
etone PROFESSIONAL SOUND
methinks your cabinets are going to be about the size of a bus....
Fs and Vas are communicating vessels with Qt as their middle man.
A driver with a higher Fs and smaller Vas, may operate similarly in a vented enclosure of similar size, as a driver with lower Fs and larger Vas, provided that the Qt of the latter is lower.
Therefore, you need to feed the parameters of the speaker you are looking at in the right formulas to help you decide if they will work in the enclosure size you are looking at.
This is an easy site for all kinds of calculations:
http://www.mh-audio.nl/spk_calc.asp
vac
A driver with a higher Fs and smaller Vas, may operate similarly in a vented enclosure of similar size, as a driver with lower Fs and larger Vas, provided that the Qt of the latter is lower.
Therefore, you need to feed the parameters of the speaker you are looking at in the right formulas to help you decide if they will work in the enclosure size you are looking at.
This is an easy site for all kinds of calculations:
http://www.mh-audio.nl/spk_calc.asp
vac
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You can modify apparent physical driver parameters by using the ACE-BASS circuit designed by K. Stahl. His U.S. patent from about 1980 or so has a good explanation of the circuit. You can model it using the program "Basta!".
-Charlie
-Charlie
I've experimented cutting the spider and surround of a driver. And softening the spider, too. (by silicon oil).
They are aiming the same goal - softening the suspensions, and all of them indeed lower the fs to some extent. But, by the very different structures and materials of all drivers, I believe there's no answer to which part is the most effective.
Some drawbacks:
1. Not reversible. Cut is cut. So you'd better do it bit by bit and examing by measurement, say, WT3 of the likes...
2. There're 2 suspensions in a woofer. The overall stiffness of the entire driver might be dominated by one of them, or pretty evenly distributed by the 2. Trying to find out which is stiffer in the first place might help.
3. The oil for softening the suspensions might gradually damage the adhesive. Generally, thicker (sticker) oil tend to be more stable; thinner one would be a better solvant... (actually I'm not 100% sure of if the glue for driver's suspension can be dissovled by oil, yet, I encountered this problem in some other things... ) And once the fabric parts get wet, they also get dirty more quickly.
4. Overall effect of moding a driver like this is not very predictable, or fitting in your purpose very well. And obviously not cost-effective. Once you fail, you simply destroy a driver. Trying (practicing) it on the cheaper one can't be a promise of sucess to another (more expensive) one.
They are aiming the same goal - softening the suspensions, and all of them indeed lower the fs to some extent. But, by the very different structures and materials of all drivers, I believe there's no answer to which part is the most effective.
Some drawbacks:
1. Not reversible. Cut is cut. So you'd better do it bit by bit and examing by measurement, say, WT3 of the likes...
2. There're 2 suspensions in a woofer. The overall stiffness of the entire driver might be dominated by one of them, or pretty evenly distributed by the 2. Trying to find out which is stiffer in the first place might help.
3. The oil for softening the suspensions might gradually damage the adhesive. Generally, thicker (sticker) oil tend to be more stable; thinner one would be a better solvant... (actually I'm not 100% sure of if the glue for driver's suspension can be dissovled by oil, yet, I encountered this problem in some other things... ) And once the fabric parts get wet, they also get dirty more quickly.
4. Overall effect of moding a driver like this is not very predictable, or fitting in your purpose very well. And obviously not cost-effective. Once you fail, you simply destroy a driver. Trying (practicing) it on the cheaper one can't be a promise of sucess to another (more expensive) one.
-- my suggest is building a real bass horn.
I am intrigued by the idea of softening the driver suspensions. Any other solutions besides silicon oil?
Which type/brand of silicon oil is recommended?
Thanks for all replies,
Herman
Which type/brand of silicon oil is recommended?
Thanks for all replies,
Herman
No brand. Nothing is marked on the plastic bottle. Ah! I remeber the oil is identical to the oil-filled gauge of Autometer. LOL ! (no! I'm not saying go buy an Autometer stuff)
Think this way. Spiders are mostly made of thick fabric. When in motion (stretched), there'd be friction among the fibers in the fabric. Oil (or any possible lubricant) in the fabric is to reduce the friction, thus the effect of softening. So, it doen't have to be silicon oil.
Eventually, softened by lubricant alone is not very effective. To achieve something more measurable, you have to cut something.
But, still, all these mods are not going to give what you want.
Impactful and dynamic bass at low level are not only relying on soft suspension. It might help a little under some conditions, but there're so many other factors. Look at those guitar drivers, their suspensions are so stiff that seem enough to stop any motion. But, how do they sound? Full of snaps !
The suspension provides not only damping, but also acts like a spring. At a transient note, VC gives the initial force, and then the suspensions pull it back right away. In this regard, suspensions are not only stopping the motion, but also contributing some of the actions. So, subjectively, I feel many stiff drivers sound "fast".
Again, I'd suggest rethink the whole thing. It's not the best route to achieve your goal.
Think this way. Spiders are mostly made of thick fabric. When in motion (stretched), there'd be friction among the fibers in the fabric. Oil (or any possible lubricant) in the fabric is to reduce the friction, thus the effect of softening. So, it doen't have to be silicon oil.
Eventually, softened by lubricant alone is not very effective. To achieve something more measurable, you have to cut something.
But, still, all these mods are not going to give what you want.
Impactful and dynamic bass at low level are not only relying on soft suspension. It might help a little under some conditions, but there're so many other factors. Look at those guitar drivers, their suspensions are so stiff that seem enough to stop any motion. But, how do they sound? Full of snaps !
The suspension provides not only damping, but also acts like a spring. At a transient note, VC gives the initial force, and then the suspensions pull it back right away. In this regard, suspensions are not only stopping the motion, but also contributing some of the actions. So, subjectively, I feel many stiff drivers sound "fast".
Again, I'd suggest rethink the whole thing. It's not the best route to achieve your goal.
Ok, CLS I agree with your reasoning regarding spider softness/stiffness. It may not be the right direction to approach. But what am I trying to accomplish?
My goal is to have great transient response at quiet listening levels. To do that giving priority to the following specs (within reason):
Rms (less than 2) which is related to:
Qms (over 20)
Mms (low)
BL (high)
these relate to transient response. Now...
I need some low bass as well, but there is no free lunch. So to have good low bass I need low Fs but at what expense? There is only left Vas and Qts. As a trade off they must be high.
Correct?
My goal is to have great transient response at quiet listening levels. To do that giving priority to the following specs (within reason):
Rms (less than 2) which is related to:
Qms (over 20)
Mms (low)
BL (high)
these relate to transient response. Now...
I need some low bass as well, but there is no free lunch. So to have good low bass I need low Fs but at what expense? There is only left Vas and Qts. As a trade off they must be high.
Correct?
AE Speaker's Lambda Dipole 15 has Fs/22Hz with only 90gr mms
if you don't play loud, or use multiple drivers, maybe it would make sense to try and get it with shorter Xmax by making voice coil a bit longer
with a dipole bass design its probably the most responsive bass for lower SPL you will ever get
I may have misunderstood
but I'm not sure I understand your project, using multiple big woofers for low SPL
a single 18" pro woofer would be more than enough
or use 12" hifi woofers
if you don't play loud, or use multiple drivers, maybe it would make sense to try and get it with shorter Xmax by making voice coil a bit longer
with a dipole bass design its probably the most responsive bass for lower SPL you will ever get
I may have misunderstood
but I'm not sure I understand your project, using multiple big woofers for low SPL
a single 18" pro woofer would be more than enough
or use 12" hifi woofers
or RCF-L18P200-N looks like a good candidate
I have thought about it myself
for a closed design
I see no point in using BR
shallow cone for a studio speaker
and it has enough Xmax for adding exstra mass/coating
RCF - L18P200-N
I have thought about it myself
for a closed design
I see no point in using BR
shallow cone for a studio speaker
and it has enough Xmax for adding exstra mass/coating
RCF - L18P200-N
It's my fault for not specifying the nature of my project:
It is a DJ/production/music listening system. The difficulty is that all three objectives are to be achieved. High accuracy/high output AND good detail at LOW listening levels. This is tricky, as I see. Tried the infinite bass layout. It's ok but it doesn't pressurize the room at low listening levels so you get the "headphone" effect where is sound is accurate but lifeless.
Rest of system is all horn loaded above 100Hz. Just adding a bass horn will cause problems as well; like delay issues and I do not want to use anything digital in the signal chain like DSP.
So back to the ported boxes. I can make two subwoofer column arrays and put them in corners behind the horns. I have 40 cu feet of space per box. So it comes down to driver selection. There's the 31" fostex woofers but they are pricey at $3200 each.
So here's the closest match, the 15" Selenium:
http://www.parts-express.com/pedocs/specs/264-464-selenium-15pw6-slf-specifications.pdf
I can use 4 per side. Cheap and effective, efficient, EXCEPT the Fs is highish 37Hz
So if I can get this DOWN to say 25Hz, I'm all set 🙂
What do you think about this reasoning?
It is a DJ/production/music listening system. The difficulty is that all three objectives are to be achieved. High accuracy/high output AND good detail at LOW listening levels. This is tricky, as I see. Tried the infinite bass layout. It's ok but it doesn't pressurize the room at low listening levels so you get the "headphone" effect where is sound is accurate but lifeless.
Rest of system is all horn loaded above 100Hz. Just adding a bass horn will cause problems as well; like delay issues and I do not want to use anything digital in the signal chain like DSP.
So back to the ported boxes. I can make two subwoofer column arrays and put them in corners behind the horns. I have 40 cu feet of space per box. So it comes down to driver selection. There's the 31" fostex woofers but they are pricey at $3200 each.
So here's the closest match, the 15" Selenium:
http://www.parts-express.com/pedocs/specs/264-464-selenium-15pw6-slf-specifications.pdf
I can use 4 per side. Cheap and effective, efficient, EXCEPT the Fs is highish 37Hz
So if I can get this DOWN to say 25Hz, I'm all set 🙂
What do you think about this reasoning?
hope I'm not offending you
but it sounds like your are holding the wrong end of the stick
and I'm even more confused now
and btw, the 31" Fostex you mention is nice and big
but its really more a delicate audiophile thing, for small amps and such
its definately not a DJ woofer
Oh, this is the first time I heard bad thing about IB bass. It pressurizes the whole space, doesn't it? Would it be other acoustic problem for that "headphone" effect?
True bass horn gives the best quality bass I've heard. Other than that, maybe multiple small sealed boxes would be very good, too. I'm not sure how it'd work in such a big system. However, OTOH, nowadays high quality high power pro woofers tend to be tuned to low Q, which is not so suitable for sealed box. Or other electrical tricks are needed...
Ported boxes are generally not so good to my ears (I haven't heard a proper Onken, though...). And I suggest, stick to 15". I myself use 18", but I always feel 15" is a better all-rounder.
True bass horn gives the best quality bass I've heard. Other than that, maybe multiple small sealed boxes would be very good, too. I'm not sure how it'd work in such a big system. However, OTOH, nowadays high quality high power pro woofers tend to be tuned to low Q, which is not so suitable for sealed box. Or other electrical tricks are needed...
Ported boxes are generally not so good to my ears (I haven't heard a proper Onken, though...). And I suggest, stick to 15". I myself use 18", but I always feel 15" is a better all-rounder.
lifeless bass like you describe it is often caused by crossover phase issues
but for DJ I don't see other options than BR
closed box, maybe
true, not many suited drivers, but there are a few
Tinitus,
Tried WinISD to model freq. resp. for RCF-L18P200-N. In a sealed 100L box is 65Hz (-3db). Shouldn't we try to go flat to at least 40Hz with a subwoofer? Even for music...
Tried WinISD to model freq. resp. for RCF-L18P200-N. In a sealed 100L box is 65Hz (-3db). Shouldn't we try to go flat to at least 40Hz with a subwoofer? Even for music...
try model with 0.5-0.6 box Q
I prefer to look at -6db and -12db point
I think it tells more
and I tend to achive a smooth rounded rolloff, by adjusting box Q and size
if I can't achieve that, then I don't like the woofer
I prefer to look at -6db and -12db point
I think it tells more
and I tend to achive a smooth rounded rolloff, by adjusting box Q and size
if I can't achieve that, then I don't like the woofer
OK, let me set this straight 🙂 I started to DJ at home because I love the music so much, I had to get more involved than just listening. The next step is to master an instrument and start composing music. So, no. DJ does not mean sh%t sound at loud levels. At least for me, it means audiophile sound, one step closer to composition.
Back to the subs:
A pair of 31" Fostex will play loud in a bass reflex 500L boxes. You got to agree with that 🙂
I do not need louder than that.
CLS, I was not talking about IB bass, I was talking about open baffle bass, like a woofer on a big panel, apologizes for miscommunication.
IB bass is great, that's what I am using now, a pair of 18" IB. It's pretty good, plays down to 16Hz 🙂 However it's not good enough for me, probably the Eminence Definimax woofers are not the best sounding, but it's bass alright. Just not fast and punchy and visceral enough. And you need a separate room!!! Very inconvenient sometimes!
So that is why I am leaning towards lighter, quicker drivers, but a larger quantity of them. Maybe eight 15" ported woofers in place of two 18" IB. That's the reasoning/experiment for me to tackle.
Back to the subs:
A pair of 31" Fostex will play loud in a bass reflex 500L boxes. You got to agree with that 🙂
I do not need louder than that.
CLS, I was not talking about IB bass, I was talking about open baffle bass, like a woofer on a big panel, apologizes for miscommunication.
IB bass is great, that's what I am using now, a pair of 18" IB. It's pretty good, plays down to 16Hz 🙂 However it's not good enough for me, probably the Eminence Definimax woofers are not the best sounding, but it's bass alright. Just not fast and punchy and visceral enough. And you need a separate room!!! Very inconvenient sometimes!
So that is why I am leaning towards lighter, quicker drivers, but a larger quantity of them. Maybe eight 15" ported woofers in place of two 18" IB. That's the reasoning/experiment for me to tackle.
sounds like what you want is 60hz kickbass, or something like that
something I personally find very annoying
but the easiest thing to achieve
a single 15" in a small closed box will do it nicely
something I personally find very annoying
but the easiest thing to achieve
a single 15" in a small closed box will do it nicely
>>sounds like what you want is 60hz kickbass
not at all. As far as output, I am looking for a pretty flat response below 100Hz, maybe down to 30Hz. I was thinking that the average 15" would be a quicker responding driver than the average 18" unless it's a really fast 18". But so far I've only found Selenium 18" and 15" with high Qms and low Rms and medium Qts. So I thought to try to buy one and modify it to have a lower Fs and as a result higher Vas.
All your advice was very good. I just need to get the point across. It's a combo of good detailed, impactfull bass at both high and low output levels I am looking for.
Sealed subs are also a great solution. Just that I have not seen a 15" woofer with low Rms, low Fs, high Qms and Qts. Have you? I'll jump on it, get 6 per side and be very happy.
not at all. As far as output, I am looking for a pretty flat response below 100Hz, maybe down to 30Hz. I was thinking that the average 15" would be a quicker responding driver than the average 18" unless it's a really fast 18". But so far I've only found Selenium 18" and 15" with high Qms and low Rms and medium Qts. So I thought to try to buy one and modify it to have a lower Fs and as a result higher Vas.
All your advice was very good. I just need to get the point across. It's a combo of good detailed, impactfull bass at both high and low output levels I am looking for.
Sealed subs are also a great solution. Just that I have not seen a 15" woofer with low Rms, low Fs, high Qms and Qts. Have you? I'll jump on it, get 6 per side and be very happy.
Ok, that leads to all kinds of possibilities.
Among loud, low and sound quality, you can only have 2 without making it very big.
Woofers on open baffles can deliver very high quality sound and loud enough, but can't do both at high SPL or very low frequency. Lifeless (or lack of punch) is usually caused by improper compensation for dipole loss. Try search for "T-bass", or "current amp"....
However, OB can't pressurize the room. Below 30, you still need some kind of box.
Anyway, your goal seems a hard one. I think of this:
http://www.diyaudio.com/forums/multi-way/90804-large-midrange-ob-scott-g-40.html#post1953221
or this:
20,000 Watt Home Hi-Fi System
Among loud, low and sound quality, you can only have 2 without making it very big.
Woofers on open baffles can deliver very high quality sound and loud enough, but can't do both at high SPL or very low frequency. Lifeless (or lack of punch) is usually caused by improper compensation for dipole loss. Try search for "T-bass", or "current amp"....
However, OB can't pressurize the room. Below 30, you still need some kind of box.
Anyway, your goal seems a hard one. I think of this:
http://www.diyaudio.com/forums/multi-way/90804-large-midrange-ob-scott-g-40.html#post1953221
or this:
20,000 Watt Home Hi-Fi System
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