Yes, I wondered these things... Although at the time I thought it was because the amp was forced to give more power, a somewhat foolish and unfounded idea probably.Nappylady said:
When you connected in parallel the Le went from 5.8mh to 2.9mh. Try the sound with it in series and an Le of 11.6mh . That should really be the proof in the pudding.
Regarding the F3's , I haven't done a hard core comparison. I trust my ears and they were in the sealed boxes of .7Q.
Sorry about the earlier post error, the Tempest has more than double the Vas (317L vs 132L) and an Fs of 18.8 vs 25hz for the JBL and a 260gram Mms for JBL and 195grams, so it may not be a fair comparison. Also, Qts .48 for JBL and .39 for Tempest...Le 1.06 in parallel for JBL and 2.8 for Tempest.
BTW, BL doesn't change with 1 VC connected vs both in parallel although series doubles it. At least according the Adire, if it doesn't involve what I can hear I have to really on others.
Regarding the F3's , I haven't done a hard core comparison. I trust my ears and they were in the sealed boxes of .7Q.
Sorry about the earlier post error, the Tempest has more than double the Vas (317L vs 132L) and an Fs of 18.8 vs 25hz for the JBL and a 260gram Mms for JBL and 195grams, so it may not be a fair comparison. Also, Qts .48 for JBL and .39 for Tempest...Le 1.06 in parallel for JBL and 2.8 for Tempest.
BTW, BL doesn't change with 1 VC connected vs both in parallel although series doubles it. At least according the Adire, if it doesn't involve what I can hear I have to really on others.
I'm trying to cut down on word length on my posts so..)
JohninCR
Advertising:
Selling high mass low force drivers trying to dispute that "speed" is a function of low mass and high force. The Gap your missing you have just answered - notice the only link is for DVC woofers (and you already know what DVC woofers will do).
Changes in inductance:
Now here is a question you should be asking - as impeadance is decreased whats happening w/ dampening factor? Current is playing a part here - but its with relation to voltage (produced by the speaker). As you decrease impeadance of the speaker, dampening factor increases. This is why things "tighten-up" BUT it isn't the holy grail of "speed" AND it can cause problems with the signal (depending on what the dampening factor is) - essential if you go to far you start geting an amplifier-like "clipped" sound. BTW, increased dampening combined with increased moving mass typically provides the sensation of "slam".
hmmm, not sure that was any shorter...)
JohninCR
Advertising:
Selling high mass low force drivers trying to dispute that "speed" is a function of low mass and high force. The Gap your missing you have just answered - notice the only link is for DVC woofers (and you already know what DVC woofers will do).
Changes in inductance:
Now here is a question you should be asking - as impeadance is decreased whats happening w/ dampening factor? Current is playing a part here - but its with relation to voltage (produced by the speaker). As you decrease impeadance of the speaker, dampening factor increases. This is why things "tighten-up" BUT it isn't the holy grail of "speed" AND it can cause problems with the signal (depending on what the dampening factor is) - essential if you go to far you start geting an amplifier-like "clipped" sound. BTW, increased dampening combined with increased moving mass typically provides the sensation of "slam".
hmmm, not sure that was any shorter...)
Far out, none of this high inductance versus low inductance stuff has anything to do with the perceived "speed" of a woofer.
🙄
🙄
Scott,
If someone is looking to buy a woofer and the goal is to have it play frequencies of say 30-100hz with force (loud) and precision just as they are on the recording (fast), what are the things to look for in the specs to indicate this ability? Are there certain ratios of different specs to look for?
If someone is looking to buy a woofer and the goal is to have it play frequencies of say 30-100hz with force (loud) and precision just as they are on the recording (fast), what are the things to look for in the specs to indicate this ability? Are there certain ratios of different specs to look for?
This is indeed becoming an interesting thread. I'm still buying the inductance thing I think. I can see me looking at Le figures next time I look at woofers.... 😉
I often wonder how low (~30hz) to lowish (~45hz) bass might be tightened up in my (or any) system - I keep thinking it's down to integration between main and sub, but it's hard to tell because so little music really works the sub ie. <50hz - and how is it really meant to sound??? I know the loading is good - 280L tuned to 20hz.. But what about box mass and vibration/movement?
So many factors and so little agreement across the board here! 😕
I often wonder how low (~30hz) to lowish (~45hz) bass might be tightened up in my (or any) system - I keep thinking it's down to integration between main and sub, but it's hard to tell because so little music really works the sub ie. <50hz - and how is it really meant to sound??? I know the loading is good - 280L tuned to 20hz.. But what about box mass and vibration/movement?
So many factors and so little agreement across the board here! 😕
Hmmm, I just thought of a very interesting idea, it won't prove anything, but it could be interesting.
I'd like people to list their most problematic music tracks, lowish-bass-wise. I think you know the ones I mean!
When we've listed enough so that more than one person knows a few we can try to decide if it's just the song, or is it one person's system, or is it.....
If I get things going by saying 'Old Skool Club Classics', anyone who owns this album and a sub will immediately think of several tracks which sound bloated and laggy. Is this just the music, or your inductance??? (etc.)
Another tricky album is Bjork - Post. Particularly the track Hyperballad - the bass can dominate the entire sound here, and as shown in another thread (I should look really) has masses of content at about 40hz and some below. Does the domination come from having too ill-defined bass, too much bass? Or something else?
We need to clarify what we are all talking about subjectively, and relate it to actual music, because if we all listen to different music, our subjective descriptions of deep bass characteristics will become meaningless.
I think the most problematic area is around 40hz, does anyone agree with that? I say this as it's still significant for a lot of music, whereas very little music has more than a lower level rumble or something below this region.
I'd like people to list their most problematic music tracks, lowish-bass-wise. I think you know the ones I mean!
When we've listed enough so that more than one person knows a few we can try to decide if it's just the song, or is it one person's system, or is it.....
If I get things going by saying 'Old Skool Club Classics', anyone who owns this album and a sub will immediately think of several tracks which sound bloated and laggy. Is this just the music, or your inductance??? (etc.)
Another tricky album is Bjork - Post. Particularly the track Hyperballad - the bass can dominate the entire sound here, and as shown in another thread (I should look really) has masses of content at about 40hz and some below. Does the domination come from having too ill-defined bass, too much bass? Or something else?
We need to clarify what we are all talking about subjectively, and relate it to actual music, because if we all listen to different music, our subjective descriptions of deep bass characteristics will become meaningless.
I think the most problematic area is around 40hz, does anyone agree with that? I say this as it's still significant for a lot of music, whereas very little music has more than a lower level rumble or something below this region.
This is an interesting thread, but I have never understood the term "fast woofer" or "fast bass".
Normally, the xover removes everything above the xover frequency before sending the signal to the woofer. So, if you xover at say 100 Hz, the woofer only gets the signal frequencies below 100 Hz (OK, not quite, because the xover is not a brick-wall filter). So there really is no need for the woofer to respond fast, it can leisurely follow the low frequencies.
Am I missing something here?
Jan Didden
Normally, the xover removes everything above the xover frequency before sending the signal to the woofer. So, if you xover at say 100 Hz, the woofer only gets the signal frequencies below 100 Hz (OK, not quite, because the xover is not a brick-wall filter). So there really is no need for the woofer to respond fast, it can leisurely follow the low frequencies.
Am I missing something here?
Jan Didden
Nothing but the entire point of the thread 😀janneman said:
Clearly, some people have a problem with the *subjective* term 'fast-bass'. If we say 'accurate-sounding' low bass, will you still dismiss it?
Well, I am dismissing nothing. Just don't understand what this fast term means. If there's an entire thread devoted to it, don't tell me it really is bull because you are really talking about accurate bass. Whatever that is, undistorted bass? Flat response? I have no problem with subjective perception etc, but I like at least to know what it is that is discussed.
I mean, how can Le have anything to do with fast bass? Is anybody implying that the Le somehow "brakes" the woofer? I am not trolling here.
Jan Didden
I mean, how can Le have anything to do with fast bass? Is anybody implying that the Le somehow "brakes" the woofer? I am not trolling here.
Jan Didden
Exactly! That's why I want people to relate their descriptions to actual music a bit more. That should clarify what we are all talking about, I hope.janneman said:
OK, I see where you're going. Will not be easy to extract a consensus from disparate subjective discriptions, but it's worth a try.
Thanks,
Jan Didden
Thanks,
Jan Didden
Okay, you mentioned Hyperballad and I just had to try it with my new system.
I'm really starting to think that the main problem with bass more about getting all the frequencies to hit at the same time.
Think about it in terms of an orchestra. If the flutists his their note 2ms before the bass drum, the conductor will have no problem hearing it, and will probably chastise them for being so sloppy! (Try listening to two trance songs set off by 2ms, and see how long it takes for you to go crazy.
)
When I play music through my full-range speakers, which are 1-way using OEM car full-range drivers ($0.89 at parts express, whoopee!), you'd better believe the bass is fast--but there's not a lot of it. When I add the 10" ported subwoofer, there's a moment of "ah, so THAT'S what the 32' subbass stop is for!" but it's also very, very slow. I did some timing tests with Cubase SX, and found that in order to get them coherent with each other, the bass cabinet needs to be placed about 3 feet (!) in front of the satellite cabinets. Once this is done, it should sound much "faster". I'm going to try that today. I'll make sure to post my results...
I'm really starting to think that the main problem with bass more about getting all the frequencies to hit at the same time.
Think about it in terms of an orchestra. If the flutists his their note 2ms before the bass drum, the conductor will have no problem hearing it, and will probably chastise them for being so sloppy! (Try listening to two trance songs set off by 2ms, and see how long it takes for you to go crazy.
)When I play music through my full-range speakers, which are 1-way using OEM car full-range drivers ($0.89 at parts express, whoopee!), you'd better believe the bass is fast--but there's not a lot of it. When I add the 10" ported subwoofer, there's a moment of "ah, so THAT'S what the 32' subbass stop is for!" but it's also very, very slow. I did some timing tests with Cubase SX, and found that in order to get them coherent with each other, the bass cabinet needs to be placed about 3 feet (!) in front of the satellite cabinets. Once this is done, it should sound much "faster". I'm going to try that today. I'll make sure to post my results...
Very interesting! Makes me wonder if my system is aided by the listener being right next to the sub, with the main speakers about 5x as far away. I think in my case it is confused by a variable phase dial on the sub, which I think I have set to about 100degrees 
I waded through this entire thread last night and see a lot of different points:
1. Some just dismiss the words "fast bass" on principle because bass is inherently slow because it is made up of the lower (slower) frequencies. I took "fast bass" to mean accurate, tight, and precise bass where you can clearly hear the individual bass notes of the instruments verses the opposite, sloppy inaccurate bass where the individual notes of the instruments run together and sound "slow".
2. Some say that it's only a factor of the enclosure. While I agree that enclosure types have a bige effect (Nappylady just stuff a sock in the port of your 10" woofer to hear the bass tighten or "speed" up), some woofers just make better bass than others regardless of the enclosure type.
3. Some say it's the crossovers and inherent delays, proper blending with the higher frequencies, etc. I agree that most of what I understood in those discussions made sense. Essentially that the frequencies accross the spectrum created by, for example, the pluck of a bass guitar string must be properly aligned in time. Again I believe this is only part of the puzzle because if you turn all of the other drivers off and keep the same low pass filtering, woofers sound different with slow, sloppy and inaccurate at one end of the spectrum and accurate, tight and "fast" at the other end.
4. Dan Wiggins (Adire) stopped in here months ago to bring up the point about Le. I'm sorry about repeating his input without reading all the way through the thread first, but it is the only thing brought up (at least that I understood and had examples) that seems tangible regarding the drivers themselves. In his test he used a very small inductor, which should only filter much higher frequencies, to demonstrate that the added inductance slowed the response of the driver while added mass did not. To me it made sense, however, when I plop down my big 9mh inductor in series with my sub it doesn't seem to cause it to produce slow, sloppy bass. To me, this means that inductance isn't the end all answer which (I think) is in agreement with what ScottG said.
Where does all this leave us? I know I still have unanswered questions as far as the drivers are concerned. I want to be able to order drivers without hearing them first and still get what I want. Other than that I agree with all of the points at least to some extent and believe they must all be considered to obtain good sounding bass that is clear, accurate, tight, and dare I use the word.... "fast".
PS-
SimonY, can you easily compare your Tempest in parallel vs series, which changes Le from 2.8mH to 11.2mH and report the results? This will also change impedance 4 fold, which may affect more than just amplifier output??? I remember trying series wiring before and I didn't like the sound, but I don't remember if it sounded sloppy and "slow" or overly dampened. Now everything is soldered and sealed making experimentation difficult.
1. Some just dismiss the words "fast bass" on principle because bass is inherently slow because it is made up of the lower (slower) frequencies. I took "fast bass" to mean accurate, tight, and precise bass where you can clearly hear the individual bass notes of the instruments verses the opposite, sloppy inaccurate bass where the individual notes of the instruments run together and sound "slow".
2. Some say that it's only a factor of the enclosure. While I agree that enclosure types have a bige effect (Nappylady just stuff a sock in the port of your 10" woofer to hear the bass tighten or "speed" up), some woofers just make better bass than others regardless of the enclosure type.
3. Some say it's the crossovers and inherent delays, proper blending with the higher frequencies, etc. I agree that most of what I understood in those discussions made sense. Essentially that the frequencies accross the spectrum created by, for example, the pluck of a bass guitar string must be properly aligned in time. Again I believe this is only part of the puzzle because if you turn all of the other drivers off and keep the same low pass filtering, woofers sound different with slow, sloppy and inaccurate at one end of the spectrum and accurate, tight and "fast" at the other end.
4. Dan Wiggins (Adire) stopped in here months ago to bring up the point about Le. I'm sorry about repeating his input without reading all the way through the thread first, but it is the only thing brought up (at least that I understood and had examples) that seems tangible regarding the drivers themselves. In his test he used a very small inductor, which should only filter much higher frequencies, to demonstrate that the added inductance slowed the response of the driver while added mass did not. To me it made sense, however, when I plop down my big 9mh inductor in series with my sub it doesn't seem to cause it to produce slow, sloppy bass. To me, this means that inductance isn't the end all answer which (I think) is in agreement with what ScottG said.
Where does all this leave us? I know I still have unanswered questions as far as the drivers are concerned. I want to be able to order drivers without hearing them first and still get what I want. Other than that I agree with all of the points at least to some extent and believe they must all be considered to obtain good sounding bass that is clear, accurate, tight, and dare I use the word.... "fast".
PS-
SimonY, can you easily compare your Tempest in parallel vs series, which changes Le from 2.8mH to 11.2mH and report the results? This will also change impedance 4 fold, which may affect more than just amplifier output??? I remember trying series wiring before and I didn't like the sound, but I don't remember if it sounded sloppy and "slow" or overly dampened. Now everything is soldered and sealed making experimentation difficult.
These PHYSICAL characteristics all work together:
Number 1: excursion for a given freq. (the low the better)
You can do this by increasing surface area (larger drivers or multiple smaller drivers), or
Horn loading, or
Using an alignment that unloads the driver for a given freq. (something like the poor-mans back-loaded horn - yes a pipe can extend freq. response but as others have mentioned the sound sucks, the trick is to get the pipes resonace low enough in level to be heard as little as possible while reducing excursion as much as possible.. Note for years JA of Stereophile thought Dave Wilson was crazy for using a bass-reflex on the WATTs - but he also noted that the midrange actually benefited from it sonically.. Now you know why.), or
Limiting Bandwidth.
Rule of thumb here: you should never be able to see the driver(s) moving.
Number 2: low energy storage, low resistance surround (for a given excursion. (i.e. a corrugated cloth surround typically; a light foam version of this like B&W's Matrix Mids use is even more sophisticated) - and yes this is even more important than #3.
Number 3: low energy storage diaphram - note that I didn't say moving mass here. You can actually have a high mass driver (relative to Sd) that helps with the "speed" characteristic. For intance - take an accuton bass mid-range driver and place it in the type of aligned bass reflex box as noted above in #1 (or FAR better back-horn load the sucker), what you will notice is that despite the high mass of the driver relative to Sd, the sound in the upper bass can be "blistering fast" (EVEN WHILE CONTRIBUTING TO A CRAPPY GROUP DELAY). Note that low mass (vs. Sd) with high rigidity helps a LOT here, as do "thin" diaphrams or variable profile diaphrams. Obviously the diaphrams material and construction can play a big part here - but typically you'll see that "good old" paper still rules because its easy to make it stiff for a given mass while keeping a VERY thin profile. For physical properties of the material itself look to Young's Modules - more for the ability to react to change than to "re-react".
Number 4: High strength magnets (otherwise known as high magnetic flux, or flux density, or gauss) relative to lower mass voice coils. Of course typically the lower the mass of the VC the lower the mass of the diaphram (actually the entire industry could be doing a LOT more research here with regard to VC material and construction). Note that you can have a low Bl driver that is VERY "fast" (but perhaps less "punchy" or "dynamic").
JohninCR:
I don't think you'll likely be able to achieve "fast" bass that low in freq. with a domestically acceptable size loudspeaker. Now you could do it down to a bit less than 50 Hz (perhaps as low as 40 Hz) and still maintain a reasnable size (depending on SPL) - then utilize a TL subwoofer below that with time delay correction by physically placing the sub closer to the listener. Make sure that the TL's driver output is essentially cut-out via steep filter (acoustic or electrical) so that the Line is only adding to the sub freq.s (not the driver's direct output). Here BL is important, as is THD at and below fs, AND HIGH linear excursion is also important(Beyma Pro has a driver or two here).
Here is a driver that will get you to 40 Hz flat in a back-horn of reasonable size: The Fostex FX200. This driver will enlighten you as to bass detail - and no, you don't have to use it full range to appreciate this quality. Oh, and don't be disuaded by the freq. response - typically speakers that have been "perfected" for their freq. response (i.e. virtually flat) turn to crap in room at listener's position. Hornresponse is a program that will do some calculations. GM and Bill Fitzmaurice are both Pro's Pros when it comes to making horns so you might talk to them about it.
SimontY:
I think that this link is pretty good as a descriptor:
http://www.tnt-audio.com/casse/lothpolaris_e.html
note that the author makes a comparison to a speaker he thought had "fast" bass located here:
http://www.tnt-audio.com/casse/sloop_e.html
Notice what the Author thinks as fast in the cabase article is somewhat similar to what you experienced by going from a single VC Titan to a Parallel VC Titan. Still though, not even close to what the LothX can do.
I'd personally describe "speed" as detail - i.e. actually being able to CLEARLY hear everything going on within that freq. spectum in time (though not necesarily in time with the rest of the freq. spectrum - though that would be FAR preferable). i.e. transient behaviour of the particular bandwidth is key - starting, stoping, and starting again relative to dynamic/SPL contrasts.
Number 1: excursion for a given freq. (the low the better)
You can do this by increasing surface area (larger drivers or multiple smaller drivers), or
Horn loading, or
Using an alignment that unloads the driver for a given freq. (something like the poor-mans back-loaded horn - yes a pipe can extend freq. response but as others have mentioned the sound sucks, the trick is to get the pipes resonace low enough in level to be heard as little as possible while reducing excursion as much as possible.. Note for years JA of Stereophile thought Dave Wilson was crazy for using a bass-reflex on the WATTs - but he also noted that the midrange actually benefited from it sonically.. Now you know why.), or
Limiting Bandwidth.
Rule of thumb here: you should never be able to see the driver(s) moving.
Number 2: low energy storage, low resistance surround (for a given excursion. (i.e. a corrugated cloth surround typically; a light foam version of this like B&W's Matrix Mids use is even more sophisticated) - and yes this is even more important than #3.
Number 3: low energy storage diaphram - note that I didn't say moving mass here. You can actually have a high mass driver (relative to Sd) that helps with the "speed" characteristic. For intance - take an accuton bass mid-range driver and place it in the type of aligned bass reflex box as noted above in #1 (or FAR better back-horn load the sucker), what you will notice is that despite the high mass of the driver relative to Sd, the sound in the upper bass can be "blistering fast" (EVEN WHILE CONTRIBUTING TO A CRAPPY GROUP DELAY). Note that low mass (vs. Sd) with high rigidity helps a LOT here, as do "thin" diaphrams or variable profile diaphrams. Obviously the diaphrams material and construction can play a big part here - but typically you'll see that "good old" paper still rules because its easy to make it stiff for a given mass while keeping a VERY thin profile. For physical properties of the material itself look to Young's Modules - more for the ability to react to change than to "re-react".
Number 4: High strength magnets (otherwise known as high magnetic flux, or flux density, or gauss) relative to lower mass voice coils. Of course typically the lower the mass of the VC the lower the mass of the diaphram (actually the entire industry could be doing a LOT more research here with regard to VC material and construction). Note that you can have a low Bl driver that is VERY "fast" (but perhaps less "punchy" or "dynamic").
JohninCR:
I don't think you'll likely be able to achieve "fast" bass that low in freq. with a domestically acceptable size loudspeaker. Now you could do it down to a bit less than 50 Hz (perhaps as low as 40 Hz) and still maintain a reasnable size (depending on SPL) - then utilize a TL subwoofer below that with time delay correction by physically placing the sub closer to the listener. Make sure that the TL's driver output is essentially cut-out via steep filter (acoustic or electrical) so that the Line is only adding to the sub freq.s (not the driver's direct output). Here BL is important, as is THD at and below fs, AND HIGH linear excursion is also important(Beyma Pro has a driver or two here).
Here is a driver that will get you to 40 Hz flat in a back-horn of reasonable size: The Fostex FX200. This driver will enlighten you as to bass detail - and no, you don't have to use it full range to appreciate this quality. Oh, and don't be disuaded by the freq. response - typically speakers that have been "perfected" for their freq. response (i.e. virtually flat) turn to crap in room at listener's position. Hornresponse is a program that will do some calculations. GM and Bill Fitzmaurice are both Pro's Pros when it comes to making horns so you might talk to them about it.
SimontY:
I think that this link is pretty good as a descriptor:
http://www.tnt-audio.com/casse/lothpolaris_e.html
note that the author makes a comparison to a speaker he thought had "fast" bass located here:
http://www.tnt-audio.com/casse/sloop_e.html
Notice what the Author thinks as fast in the cabase article is somewhat similar to what you experienced by going from a single VC Titan to a Parallel VC Titan. Still though, not even close to what the LothX can do.
I'd personally describe "speed" as detail - i.e. actually being able to CLEARLY hear everything going on within that freq. spectum in time (though not necesarily in time with the rest of the freq. spectrum - though that would be FAR preferable). i.e. transient behaviour of the particular bandwidth is key - starting, stoping, and starting again relative to dynamic/SPL contrasts.
Thanks for the info Scott and for not talking down to those of us less knowlegeable.
Actually I'm into dipoles and plan to make a dipole sub using 32-40 or more if needed 6" $3 TV speakers that make good bass on OB. I'm hoping for good output down in the teens for LFE's. Yeah, it'll be fairly big and long, but I have a plan so it won't very noticeable.
Actually I'm into dipoles and plan to make a dipole sub using 32-40 or more if needed 6" $3 TV speakers that make good bass on OB. I'm hoping for good output down in the teens for LFE's. Yeah, it'll be fairly big and long, but I have a plan so it won't very noticeable.
ScottG said:
This is a very good point. Dr Jordan wrote years ago that hysteresis in the cone was a bad thing, and this is the reason he uses metal cones for his full - range speakers. With plastic cones (such as polypropylene), when they flex they don't go back to their original position. I expect this would mostly effect the harmonics, and could be interpreted as "slow" when they are reproducing music, even though the frequency response measures flat.
"dipole sub using 32-40 or more if needed 6" $3 TV speakers "
you probably will run into prob.s with harmonic distortion
anytime a driver goes below fs you run a substantial risk of harmonics louder than the signal (for 2nd order this is called "doubling"). On the otherhand mid and upper bass should be excellent.
you probably will run into prob.s with harmonic distortion
anytime a driver goes below fs you run a substantial risk of harmonics louder than the signal (for 2nd order this is called "doubling"). On the otherhand mid and upper bass should be excellent.
I'll probably keep it at 1 watt or less for each driver to minimize excursion and related distortion for the really low stuff. Down out of the musical range distortion won't be much of a factor anyway since that will be just for LFE's. We'll see what they can do.
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