pinkmouse said:
Yes, I can swallow that. So let's use the term "tight bass" 🙂
Dr.EM said:
The lower the Q the potentially tighter or perhaps "dryer" the bass can be. It has a lot to do with the cabinet/driver combination.
pinkmouse said:
pinkmouse your reason is good but i think that why the subwoofer for rogers 3/5 A that they only use 5" bandpass sub. why don't they use 10 " sub driver for it? isn't good? not fast bass?
TW
Interesting point! My only response is that perhaps they wanted the bandpass roll off to simplify installation and save on big inductors.You have to also remember that the LS3 was designer to be used in the back of an OB truck, a very small space, so the size of the sub may well have been an acceptable compromise between performance and volume in an already compromised setup
AMV8 said:
IMHO, the transient response is also important. The bass reflex (in one simplified perspective) works by taking the back wave of the speaker, delaying a half cycle, and pumping it out to join the front wave in phase. But this delay inherently smears the envelope of the bass sound being reproduced.
I need to check my books to verify, but IIRC the Bessel alignment (Q=0.5) has zero overshoot but takes some time to reach a step input, Butterworth at Q=0.71 is well regarded for minimizing time to achieve a step input but with a bit of overshoot.
But then the attack on a bass string isn't going to be a step function. It would be interesting to see some waveforms of real bass instruments that possess the "fast & tight" property. What is their attack time?
Hmm, an interesting project for beer time🙂
Iain McNeill said:
Yup!
I suspect a FFT breakdown would be more useful, perhaps as a waterfall, so it can be seen over time.
Couldn't agree with you more!
Even if it was a step function, the subwoofer wouldn't see that because all those higher frequencies will be removed by the crossover.Iain McNeill [/i][B]...I need to check my books to verify said:
dear oon_the_kid san,
Sorry for my bad English. �gbellows ???�h => �gfollowings�h
I just wanted to say,
If �gfast�h means �gnon-delay�h and �ganechoic�h, the room condition as well as level & phase adjustment based on measurements is very important with any types of speakers.
I think it�fs a good idea to use a graphic equalizer. You can assist the roll-off of the sealed box..
Inner-ear type earphones deliver super fast (or tight and clear) bass (low-end 5 Hz).
You can use them as a reference.
The fastest bass I've heard was from a sealed box, and there is reasoning behind this.
Ported/bandpass systems rely on ports to delay the sound 1/2 a cycle, the send it out roughly in phase with the sound from the front of the woofer.
Horn loaded systems involve sending the sound waves a very long way compared to sealed enclosures, so there will be need for phase control.
I have compared the bass from a sealed box, and a ported box with the same driver, and I found the sealed a lot faster and tighter, but the ported seemed to go lower...
Not 100% sure on this, but could the speed/tightness of the bass rely on the mechanical damping of the driver and box, or at least be affected by this?
Reasoning behind this:
If a driver plays a note, a perfect driver would start and stop as soon as the input starts and stops. If you have a driver with a low mech. damping, wouldn't it carry on flapping around for a while after the note had stopped??? If it did, it would mean the note would more "fade away" rather than stop.
Just my experience...
Ported/bandpass systems rely on ports to delay the sound 1/2 a cycle, the send it out roughly in phase with the sound from the front of the woofer.
Horn loaded systems involve sending the sound waves a very long way compared to sealed enclosures, so there will be need for phase control.
I have compared the bass from a sealed box, and a ported box with the same driver, and I found the sealed a lot faster and tighter, but the ported seemed to go lower...
Not 100% sure on this, but could the speed/tightness of the bass rely on the mechanical damping of the driver and box, or at least be affected by this?
Reasoning behind this:
If a driver plays a note, a perfect driver would start and stop as soon as the input starts and stops. If you have a driver with a low mech. damping, wouldn't it carry on flapping around for a while after the note had stopped??? If it did, it would mean the note would more "fade away" rather than stop.
Just my experience...
chris661 said:
If horn is designed correctly, mouth out is in phaze with direct radiation. Just should not go with horns below 40-50Hz to have everything ok with phaze. I did not here quicker and cleaner upper bass than with horn.
The problem with arguing over different designs of sub is that to properly compare them by listening you would need them to be EQ'd to have the same response and roll off. If for instance you compare sealed with ported then, as Al (Pinkmouse) said the one with less 'sub' will sound faster. So you will probably conclude that the sealed design sounds faster because it has less group delay, better design etc when in fact it has a frequency response that favours the 'fast' band of freq's.
To compare properly you would need to have each type of speaker available and a parametric EQ. I reckon if they're all EQ'd the same then it would be quite hard to hear the differences.
My opinion is that for 'fast' bass you need to be looking at the quality of the speaker in the 40Hz - 200Hz region. I've had a lot better success using high quality drivers / low distortion type setups (15" horns, 15" pro drivers sealed, 2 x 10" Scanspeaks etc) for the midbass area and using the sub below ~40 - 50Hz.
Basically you need a low distortion, high output midbass system to get a 'clean, fast' double bass sound rather than using a conventional sub setup.
Best systems I've heard using subs up to 80Hz have been all horn systems or servo feedback type subwoofers. Both known for low distortion.
Rob.
To compare properly you would need to have each type of speaker available and a parametric EQ. I reckon if they're all EQ'd the same then it would be quite hard to hear the differences.
My opinion is that for 'fast' bass you need to be looking at the quality of the speaker in the 40Hz - 200Hz region. I've had a lot better success using high quality drivers / low distortion type setups (15" horns, 15" pro drivers sealed, 2 x 10" Scanspeaks etc) for the midbass area and using the sub below ~40 - 50Hz.
Basically you need a low distortion, high output midbass system to get a 'clean, fast' double bass sound rather than using a conventional sub setup.
Best systems I've heard using subs up to 80Hz have been all horn systems or servo feedback type subwoofers. Both known for low distortion.
Rob.
So where does a Tapped Horn fall on the scale for "tight clean" bass. I know it provides greater SPL and LF range over sealed but how much does it give up in the "clean" department to accomplish this? From what I've read, cone control is very good which keeps distortion low but it will suffer from ripple.
I'm planning on building a pair of the 38Hz TH for the Tang Band W6-1139SI.
I'm planning on building a pair of the 38Hz TH for the Tang Band W6-1139SI.
Hi oon_the_kid,
tritosine provided a most important and accurate answer to the fast part of your question in Post #4. This should be compulsory reading for any new speaker builder. 🙂
For minimal woodworking, something like the PartsExpress Dayton ES10 Elite Series 150 Watt 10" powered subwoofer might fit the bill (@ $138.--ea.), give you a good starting point to compare the sound of vented v. sealed, and can be used as a test bed for other drivers. Stuffing a foam plug into the port should kill the port output.
Regards,
tritosine provided a most important and accurate answer to the fast part of your question in Post #4. This should be compulsory reading for any new speaker builder. 🙂
For minimal woodworking, something like the PartsExpress Dayton ES10 Elite Series 150 Watt 10" powered subwoofer might fit the bill (@ $138.--ea.), give you a good starting point to compare the sound of vented v. sealed, and can be used as a test bed for other drivers. Stuffing a foam plug into the port should kill the port output.
Regards,
Dear Rob Wells,
I agree with you in many ways. I think the fundamental problem is this. If you want a low resonant frequency but you can't reduce the spring constant, the only way you can do it is by increasing mass. If you look into most 10" and 12" sub they tend to have Mms of 150-200gm. Relatively a 8" sub can be around 30-50gm. But you may argue that motor force(BL) increases. But actually the don't increse much, only about 50% more versus a 5 time increment in moving mass. This is true even for woofers of the same manufacuter.
The problem is I am trying to get my sub to do the woofer's work. So you are absoultely right, get a woofer to do the job instead of a subwoofer. Woofers have much lower mass and hence respond faster. So getting a woofer to do a subwoofers job instead of the other way around may seem more sensible. In fact another speaker I considered was the scanspeak 8535. Apparently pretty good bass. Only problem is the Vas tend to be enormous, something to the tune of a undred litres. Its going to be floostander sub...
I am thinkng of a much smaller one...
Oon
I agree with you in many ways. I think the fundamental problem is this. If you want a low resonant frequency but you can't reduce the spring constant, the only way you can do it is by increasing mass. If you look into most 10" and 12" sub they tend to have Mms of 150-200gm. Relatively a 8" sub can be around 30-50gm. But you may argue that motor force(BL) increases. But actually the don't increse much, only about 50% more versus a 5 time increment in moving mass. This is true even for woofers of the same manufacuter.
The problem is I am trying to get my sub to do the woofer's work. So you are absoultely right, get a woofer to do the job instead of a subwoofer. Woofers have much lower mass and hence respond faster. So getting a woofer to do a subwoofers job instead of the other way around may seem more sensible. In fact another speaker I considered was the scanspeak 8535. Apparently pretty good bass. Only problem is the Vas tend to be enormous, something to the tune of a undred litres. Its going to be floostander sub...
I am thinkng of a much smaller one...
Oon
hi oon_the_kid
you're alright. scanspeak 8535 is very soft bass but scanspeak 8545 seem to be better than 8535. it's not soft too much but it's fast.
TW
you're alright. scanspeak 8535 is very soft bass but scanspeak 8545 seem to be better than 8535. it's not soft too much but it's fast.
TW
For fast transient response subwoofers in the 100 hz range, I would suggest low compression designs such as horns or if infinite baffle or sealed, lots of surface area. I personally think that infinite baffle is the best of these because you also get very low frequency response, but efficient at low frequencies.
The box would need to be very stiff - flexing of the box results in softer dynamics. The very large size of horns makes this more difficult to do, but worthwhile.
The other thing not discussed here so far is the quality of the amp and any crossover. If you get the speaker optimized, then the amp has to be very low distortion too. Either purchase a very high quality amp, or buy a good pro amp and have it modified (parallel smaller capacitors with the large capacitors in the power suppy, use fast recovery diodes). If using an electronic crossover, make sure that it is of high quality, or have it modded.
The last item is to be sure that the phase of the subwoofer is exactly the same as the main drivers. If the phase is off, it won't matter how dynamic the subs are, you will be disappointed.
Retsel
The box would need to be very stiff - flexing of the box results in softer dynamics. The very large size of horns makes this more difficult to do, but worthwhile.
The other thing not discussed here so far is the quality of the amp and any crossover. If you get the speaker optimized, then the amp has to be very low distortion too. Either purchase a very high quality amp, or buy a good pro amp and have it modified (parallel smaller capacitors with the large capacitors in the power suppy, use fast recovery diodes). If using an electronic crossover, make sure that it is of high quality, or have it modded.
The last item is to be sure that the phase of the subwoofer is exactly the same as the main drivers. If the phase is off, it won't matter how dynamic the subs are, you will be disappointed.
Retsel
Fast bass discussions can be murky waters to navigate because we all have different ideas about what it means and how it can be achieved. It's no wonder it can get heated!
It's not a term that I use - better to use terms that others will understand in the same way. Still, I tend to think of fast bass as meaning both accurate and tight.
Let's say you have a sub that is accurate. EQ out the deep bass and people will consider it tighter, as Pink Mouse mentioned.
Still, I think there is more to it than that. Let's take two different subs with the exact same response - one can still sound tight while the other can sound bloated, sloppy, etc.
In other words, I believe you have to consider a lot of different factors.
My search for accurate bass lead to my current subs - two 12" sealed Rythmik kits. They are tight while at the same time deep. When I first heard them my first impression was that they sounded like some fantastic sounding Focal Audiom drivers (yet the active kit cost less than the Focal drivers alone and can also work for HT with much more low end output).
With other subs I couldn't help but notice that despite using EQ to get a flat response in both cases, I could tell when a sub was present. My mains would happily get down to 23 Hz without boost, and they were tight and articulate. The subs were a step back in accuracy, but a huge step forward in low end grunt. The Rythmik kits had the best of both.
Looking at the Home Theatre Shack measurements is interesting. While the low end distortion isn't brilliant, they still sound very clean and dry. The distortion 40 - 100 Hz is ultra low. I also notice that the higher order distortion is extremely low in this range. It's easy to overlook this, but considering what I've read regarding Geddes Gedlee metric, I suspect that if distortion measurements were weighted in a way that corresponded to our perception, we'd be better able to compare the measurements. I also noticed that the Rythmik performed very well in the time domain, better than any of the others that I noticed.
I think it's a trap to look at just one aspect and think that one thing alone can tell you what will be faster. It may be true if all other things are equal, but they rarely are.
If you take two identical drivers and make one lighter, what happens? I've discussed this with Brian at Rythmik regarding their aluminium vs paper drivers. His answer was that the lighter paper cones are an advantage at lower output, however, the aluminium cones perform better at higher excursion due to less flexing from the internal box pressure. If you have an IB situation, then this aspect is removed, and a light paper cone makes more sense. Yet, they are often made heavier to get a lower fs.
In the end, any design requires a careful balance of many different factors that all work together. The interaction between all those factors can become complex. I doubt that industry leading experts fully understand them all and exactly how they translate into what we perceive, much less us (mostly) untrained yet often highly opinionated hobbyists!
When it comes to ideas like "smaller or lighter drivers are faster" I'd say the short answer is "not necessarily."
No one has mentioned the room yet! If your room has really nasty modes, then the best approach could look very different. In that case, a solution could be 3 or 4 active woofers or subs and some parametric eq.
Tapped horns are interesting in this discussion. Those who hear them describe the sound as tight and fast, even with a very deep response generally. I can't say I've heard them, but assuming it is true that they are tight, accurate and fast, why would it be true? From what I can tell, they increase efficiency by about 7db and double the effective driver piston area (extra 6db). The latter is achieved with a vented box, but the extra output is only applied over a narrow band to extend response. If I'm not mistaken this means 13 db more output. Hence for the same output, less excursion and less power and much lower distortion. Obviously this all helps accuracy greatly.
I'm also curious about the impact of the way in which both sides of the cone are loaded. In a sealed box, all the pressure is on one side. In a back loaded horn, I've heard it said that the aim is to equally load both sides of the cone, which in effect forces the driver to operate as if the motor itself were more linear.
...
I just had a quick look at the PDF in post 4 and it does appear very interesting!
...
The wavecor driver appears very inefficient. Despite the acceptable calculated 86 db, the chart shows 82 db at best! I wouldn't touch it.
It's not a term that I use - better to use terms that others will understand in the same way. Still, I tend to think of fast bass as meaning both accurate and tight.
Let's say you have a sub that is accurate. EQ out the deep bass and people will consider it tighter, as Pink Mouse mentioned.
Still, I think there is more to it than that. Let's take two different subs with the exact same response - one can still sound tight while the other can sound bloated, sloppy, etc.
In other words, I believe you have to consider a lot of different factors.
My search for accurate bass lead to my current subs - two 12" sealed Rythmik kits. They are tight while at the same time deep. When I first heard them my first impression was that they sounded like some fantastic sounding Focal Audiom drivers (yet the active kit cost less than the Focal drivers alone and can also work for HT with much more low end output).
With other subs I couldn't help but notice that despite using EQ to get a flat response in both cases, I could tell when a sub was present. My mains would happily get down to 23 Hz without boost, and they were tight and articulate. The subs were a step back in accuracy, but a huge step forward in low end grunt. The Rythmik kits had the best of both.
Looking at the Home Theatre Shack measurements is interesting. While the low end distortion isn't brilliant, they still sound very clean and dry. The distortion 40 - 100 Hz is ultra low. I also notice that the higher order distortion is extremely low in this range. It's easy to overlook this, but considering what I've read regarding Geddes Gedlee metric, I suspect that if distortion measurements were weighted in a way that corresponded to our perception, we'd be better able to compare the measurements. I also noticed that the Rythmik performed very well in the time domain, better than any of the others that I noticed.
I think it's a trap to look at just one aspect and think that one thing alone can tell you what will be faster. It may be true if all other things are equal, but they rarely are.
If you take two identical drivers and make one lighter, what happens? I've discussed this with Brian at Rythmik regarding their aluminium vs paper drivers. His answer was that the lighter paper cones are an advantage at lower output, however, the aluminium cones perform better at higher excursion due to less flexing from the internal box pressure. If you have an IB situation, then this aspect is removed, and a light paper cone makes more sense. Yet, they are often made heavier to get a lower fs.
In the end, any design requires a careful balance of many different factors that all work together. The interaction between all those factors can become complex. I doubt that industry leading experts fully understand them all and exactly how they translate into what we perceive, much less us (mostly) untrained yet often highly opinionated hobbyists!
When it comes to ideas like "smaller or lighter drivers are faster" I'd say the short answer is "not necessarily."
No one has mentioned the room yet! If your room has really nasty modes, then the best approach could look very different. In that case, a solution could be 3 or 4 active woofers or subs and some parametric eq.
Tapped horns are interesting in this discussion. Those who hear them describe the sound as tight and fast, even with a very deep response generally. I can't say I've heard them, but assuming it is true that they are tight, accurate and fast, why would it be true? From what I can tell, they increase efficiency by about 7db and double the effective driver piston area (extra 6db). The latter is achieved with a vented box, but the extra output is only applied over a narrow band to extend response. If I'm not mistaken this means 13 db more output. Hence for the same output, less excursion and less power and much lower distortion. Obviously this all helps accuracy greatly.
I'm also curious about the impact of the way in which both sides of the cone are loaded. In a sealed box, all the pressure is on one side. In a back loaded horn, I've heard it said that the aim is to equally load both sides of the cone, which in effect forces the driver to operate as if the motor itself were more linear.
...
I just had a quick look at the PDF in post 4 and it does appear very interesting!
...
The wavecor driver appears very inefficient. Despite the acceptable calculated 86 db, the chart shows 82 db at best! I wouldn't touch it.
paulspencer said:
BINGO!!
All the talk about uncontrolled resonances, etc... is mindless w/o mentioning the room and location of the sub(s)... since most any room has all sorts of resonances and reflections impacting the reproduction. In fact, the room resonance profile defines the bass reproduction, the speakers only provide the drive for these modes.
In most instances, the room dominates the reproduction quality below say 100 hz, so fast and slow applied to the drivers doesn't seem to apply much. So deal with the room modes (through placement, multiple sources, etc.) and bass quality will be dramatically enhanced. Chasing driver characteristics pretty much misses the point, imo
John L.
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