Hi,
I am looking at how to design for a fast sub, fast as in good transient response. Before I begin, maybe a bit of background. I am planning to mate it with a Markaudio alpair 6 satelite. Now the thing with maiting it with a 6 cm driver is, the sub actually has to do quite a bit of normal bass too. I find the bass from most sub a bit too wooly, does not fell like a punchy bass from a well built floor stander. Good for HT rumble, but not good for a double bass.
So, basically a tight and accurate bass is important, very low end is secondary. Maybe something in the design philosophy of this one:
http://www.philjonespuresound.com/PJWeb13_PSW1.aspx
So I would like some advice on how to build such a sub. Since I am not a real woodwork guy, I would probably a) buy a speaker cabinet and put in a suitable driver b) buy an old second hand sub and replace the driver and modify it.
There seems to be quite a bit of fallacy and facts running around the internet so it would be good if some of you guys help clear it up for me especially if it is a misconception.
a) I should be using a sealed cabinet for better tightness and clarity. Cabinet size would be about Vas.
b) I should be using smaller speakers, or speaker with a high force factor / moving mass ratio.
c) the high inductance and hence the emf from the subwoofer at near fs is the problem, causing poor bass response.
However looking at these constraints, i noticed that for b) the speaker would have to be a 7" or 8" subwoofer drivers. 10" drivers have significantly higher Mms. Alternatively I could use normal 10" woofers which have smaller Mms rather than subwoofers but their Vas tends to be quite huge.
I might be interested in this:
http://www.wavecor.com/html/sw178wa01.html
Has anybody used this driver before and can comment on it.
Or is there another 10" driver that you might want to recommend?
To cater for the poorer low end response, I would like to add in a 5 band graphic equaliser (for the bass band only), which also helps for tuning of the room and to compenste for the bass roll off.
So overall, it would be a 7" or 8" sub in a sealed enclosure with a 5 band graphic equaliser on the inputs.
Any comment is greatly welcomed.
Oon
I am looking at how to design for a fast sub, fast as in good transient response. Before I begin, maybe a bit of background. I am planning to mate it with a Markaudio alpair 6 satelite. Now the thing with maiting it with a 6 cm driver is, the sub actually has to do quite a bit of normal bass too. I find the bass from most sub a bit too wooly, does not fell like a punchy bass from a well built floor stander. Good for HT rumble, but not good for a double bass.
So, basically a tight and accurate bass is important, very low end is secondary. Maybe something in the design philosophy of this one:
http://www.philjonespuresound.com/PJWeb13_PSW1.aspx
So I would like some advice on how to build such a sub. Since I am not a real woodwork guy, I would probably a) buy a speaker cabinet and put in a suitable driver b) buy an old second hand sub and replace the driver and modify it.
There seems to be quite a bit of fallacy and facts running around the internet so it would be good if some of you guys help clear it up for me especially if it is a misconception.
a) I should be using a sealed cabinet for better tightness and clarity. Cabinet size would be about Vas.
b) I should be using smaller speakers, or speaker with a high force factor / moving mass ratio.
c) the high inductance and hence the emf from the subwoofer at near fs is the problem, causing poor bass response.
However looking at these constraints, i noticed that for b) the speaker would have to be a 7" or 8" subwoofer drivers. 10" drivers have significantly higher Mms. Alternatively I could use normal 10" woofers which have smaller Mms rather than subwoofers but their Vas tends to be quite huge.
I might be interested in this:
http://www.wavecor.com/html/sw178wa01.html
Has anybody used this driver before and can comment on it.
Or is there another 10" driver that you might want to recommend?
To cater for the poorer low end response, I would like to add in a 5 band graphic equaliser (for the bass band only), which also helps for tuning of the room and to compenste for the bass roll off.
So overall, it would be a 7" or 8" sub in a sealed enclosure with a 5 band graphic equaliser on the inputs.
Any comment is greatly welcomed.
Oon
Hi,
I'm a recent new member of this forum.
I hope this kind of information could be useful for you;
Recently I have studied a subwoofer integration to my desktop audio system.
The target was to create earphones-like very tight and clear super bass (down to 30 Hz flat).
Although the circumstances maybe much different from your listening style, I believe the basic theories could be applicable also to you.
I�fve found bellows are very important besides the unit design;
1) Standing wave effect (sound reflections from walls) in the room should be reduced.
For that:
- Find the best position of the subwoofer anywhere in the room
- or install it very near from you (delay control necessary)
(see attached figure)
2) Equalize the output and phase delay accurately based on measurements at the actual listening position.
3) Digital signal processing is quite useful for the adjustments
4) Relatively small sealed enclosures for the main speakers (maybe 2 �c 3 L for Alpair 6)
5) A sealed enclosure could be better also for the subwoofer (or duct stuffing)
For details, please see my own Blog
http://lean-audio.blogspot.com/
I'm a recent new member of this forum.
I hope this kind of information could be useful for you;
Recently I have studied a subwoofer integration to my desktop audio system.
The target was to create earphones-like very tight and clear super bass (down to 30 Hz flat).
Although the circumstances maybe much different from your listening style, I believe the basic theories could be applicable also to you.
I�fve found bellows are very important besides the unit design;
1) Standing wave effect (sound reflections from walls) in the room should be reduced.
For that:
- Find the best position of the subwoofer anywhere in the room
- or install it very near from you (delay control necessary)
(see attached figure)
2) Equalize the output and phase delay accurately based on measurements at the actual listening position.
3) Digital signal processing is quite useful for the adjustments
4) Relatively small sealed enclosures for the main speakers (maybe 2 �c 3 L for Alpair 6)
5) A sealed enclosure could be better also for the subwoofer (or duct stuffing)
For details, please see my own Blog
http://lean-audio.blogspot.com/
Attachments
If you want "fast" bass look at good BIG PRO woofers
Smaller woofers going low tend to get "slow" and blurred
Smaller woofers going low tend to get "slow" and blurred
Fast is just a bad term to use. Simply, a fast woofer has good hi-frequency response. Put a low pass filter on it, and it is no longer fast.
What i think you are looking for is a bass driver that accurately reacts to the input signal without. This probably comes down to a good motor design, low inductance, good downward dynamic range, and low group delay when it gets into the box.
dave
What i think you are looking for is a bass driver that accurately reacts to the input signal without. This probably comes down to a good motor design, low inductance, good downward dynamic range, and low group delay when it gets into the box.
dave
Well, you can actually have a bass that is too fast, which means its out of phase resulting in poor timing
Bass is best when slow and relaxed 😀
Besides, bassplayers are slow guys with slow instruments
You cant play fast on tuba either
What I desire is the clear pitching from the strings on a contrabass 😎
But to quit the bogus, I think that theoretically you need a woofer thats good and clean all the way up to its natural rolloff
It will give you the chance to try crossing a bit higher as I reckon your fullrange needs some support in lower mid/midbass
Im thinking whether the new underhung midwoofers from Tangband would work nice
Bass is best when slow and relaxed 😀
Besides, bassplayers are slow guys with slow instruments
You cant play fast on tuba either
What I desire is the clear pitching from the strings on a contrabass 😎
But to quit the bogus, I think that theoretically you need a woofer thats good and clean all the way up to its natural rolloff
It will give you the chance to try crossing a bit higher as I reckon your fullrange needs some support in lower mid/midbass
Im thinking whether the new underhung midwoofers from Tangband would work nice
I don't think you need a sub, I think you need a pair of woofers that respond low - The Wavecor drivers look suitable, but will probably need a notch for that HF peak.
BR will give you a much more solid bass, and you won't need the eq - less strain on your amp
Using a 1st order xover, you can also use the woofers to compensate for BSC
BR will give you a much more solid bass, and you won't need the eq - less strain on your amp
Using a 1st order xover, you can also use the woofers to compensate for BSC
tinitus i don't understand why big woofers will be fast. and if 30" driver(fostex) do u think it will be fast?
planet10! i ever heard Scan Speak 18W8535(7")driver for sub. i think, fast is good. fs of it around 25 hz. 54 litre vent box. -3db about 35 hz
when put low pass filter about 100 hz. it still be fast. sorry! planet10 i understand the meaning for your reply a little.
regards
TW
Thawach said:
As soon as you put a LP on it, it can't be fast, because there is no signal to be fast. You are using the wrong word. a 100 Hz signal just isn't fast. A 20k one is.
dave
Thawach said:
What Dave says is true
But we also know perfectly clear what you mean by "fast" bass
Unless if it means that you have listened to people saying that small woofers are "faster"
They are, as Dave explained, only at higher frequencies
Bigger woofers are considered "faster"
because they move less, due to their bigger sizeLets refrase and say, more responsive, at low frequencies
When you refer to "fast", it actually means "tight", precise bass
Its mostly related to driver Qts, and the following box design
Small woofers designed to be "tight", easily results in thin almost absent bass
You could call it "mouse" bass
Small genuine sub drivers going really low is a different matter
Big woofers have more volume, and are better suited fore a design with "tight" bass
Such a driver will have a big powerful "motor", and therefore subjectively sound more responsive
Even with a "tight" design you will still hear the bass as BIG
But one should still take great care not to get boomy sound
The catch is that one cant expect to "feel" the subbass, but its more like something you "hear", which is actually really nice in the long run
Some prefer dipole bass fore the same reason
I believe many are using your driver in a dipole setup
To get the right balance it would need to be active
Theres actually a lot more to it than that, and its too complicated to explain like this
And there still remains the room issues
It will never just be "plug and play"
Okay, let me clear the air on the bass (pun intended). I want a tight accurate bass, similar to the type you would get from a good floor stander with all the slam included. I would like a drum to sound like a drum and not a double bass.
If i understand correctly, the correct term would be called good transient response.
My thoughts are, it would need a good motor force (BL) to Mms ratio. Maybe a good indicator of a woofer that has this capability wiould be one which actually respond to a few KHz.
Thanks for all the responses so far.
Dear Matsumoto,
Just would liek to clarify, what do you mean by bellows?
Oon
If i understand correctly, the correct term would be called good transient response.
My thoughts are, it would need a good motor force (BL) to Mms ratio. Maybe a good indicator of a woofer that has this capability wiould be one which actually respond to a few KHz.
Thanks for all the responses so far.
Dear Matsumoto,
Just would liek to clarify, what do you mean by bellows?
Oon
This is a conversation I have frequently with sound guys, (and Gals!) or semi-pro musicians looking for their first upgrade to pro systems. What 95% of them mean by fast bass, and I have demonstrated it both to myself and to their satisfaction, is a system that has rolled off low end, below about 40-60 Hz, depending on taste.
Now some people may get all hot and bothered about this, but it's your music and your system, and you have to live with it, not them. So, I would look for a half decent 10" driver, in a sealed box, tuned to, say 40Hz, and see how you get on from there.
Now some people may get all hot and bothered about this, but it's your music and your system, and you have to live with it, not them. So, I would look for a half decent 10" driver, in a sealed box, tuned to, say 40Hz, and see how you get on from there.
Pinkmouse
Instinctively I agree with you. But why do you feel a sealed box is better than a bass reflex cabinet when a bass reflex cabinet could be tuned to roll off more steeply at 40 - 60Hz.
Don
Instinctively I agree with you. But why do you feel a sealed box is better than a bass reflex cabinet when a bass reflex cabinet could be tuned to roll off more steeply at 40 - 60Hz.
Don
Don, two main reasons, having some low end is still nice, and you get that with the gentler roll off of a sealed box, and sealed is easier to design and build, and requires less tuning to optimise performance with a given driver and room.
But then again, it's horses for courses! 😀
But then again, it's horses for courses! 😀
fast bass
From my experience a smaller woofer will react "faster" to electrical signals. The lower mass of the cone and coil respond and nutralize faster than a large mass driver. It is all reletive though. There are many design considerations to address. If you want a sealed infinite baffle cabinet you must make it large and solid. Knock on a speaker box and see if it hurts your knuckles and sounds like it is a solid piece of wood. Infinite baffles require a large volume of trapped air within the cabinet. Shape is also important. Try thinking "outside the box" and come up with different cabinet shapes. Parellel and perpendicular surfaces inside the box increase internal cabinet resonence and can cancel out the sound waves. This is most important with bass reflex designs. My most sucessfull designs are not box shaped.
From my experience a smaller woofer will react "faster" to electrical signals. The lower mass of the cone and coil respond and nutralize faster than a large mass driver. It is all reletive though. There are many design considerations to address. If you want a sealed infinite baffle cabinet you must make it large and solid. Knock on a speaker box and see if it hurts your knuckles and sounds like it is a solid piece of wood. Infinite baffles require a large volume of trapped air within the cabinet. Shape is also important. Try thinking "outside the box" and come up with different cabinet shapes. Parellel and perpendicular surfaces inside the box increase internal cabinet resonence and can cancel out the sound waves. This is most important with bass reflex designs. My most sucessfull designs are not box shaped.
Re: fast bass
A smaller woofer also needs to sweep more to displace the same volume of air as a larger woofer. If it has half the Sd (an 8" compared to a 12" - both of which are small for bass reproduction), it NEEDS to sweep (excursion) twice as much as the 12". Distortion is quite obviously higher - for an apples to apples comparison, exactly double. Likely more, as motors are linear for only a few mm +/-, unless they're very high-end.
To properly qualify the "a smaller woofer will react "faster"" objectively, which is what you're saying when you say "From my experience" take two woofers from the same series (ie: Peerless SLS), put them in an enclosure with the same alignment (ie: Q=0.5 sealed), and THEN listen to it and let us know if you still believe what you wrote.
Their is no correlation between magnet size, cone diameter, or most other INDIVIDUAL factors in bass reproduction - they are part of a system, and the end response of the system is what matters.
I feel like Dan Lavry talking about power supplies at this point...
Just my $0.02... I've heard this discussion too many times.
If you want "fast" bass, pick up a Rythmik Audio subwoofer, or build a low Q sealed enclosure. Or dipole bass, and EQ to taste.
Or to quote a fellow on the forum, if you really want "fast" bass - get a tweeter.
cheers,
-Tal
bizman said:
A smaller woofer also needs to sweep more to displace the same volume of air as a larger woofer. If it has half the Sd (an 8" compared to a 12" - both of which are small for bass reproduction), it NEEDS to sweep (excursion) twice as much as the 12". Distortion is quite obviously higher - for an apples to apples comparison, exactly double. Likely more, as motors are linear for only a few mm +/-, unless they're very high-end.
To properly qualify the "a smaller woofer will react "faster"" objectively, which is what you're saying when you say "From my experience" take two woofers from the same series (ie: Peerless SLS), put them in an enclosure with the same alignment (ie: Q=0.5 sealed), and THEN listen to it and let us know if you still believe what you wrote.
Their is no correlation between magnet size, cone diameter, or most other INDIVIDUAL factors in bass reproduction - they are part of a system, and the end response of the system is what matters.
I feel like Dan Lavry talking about power supplies at this point...
Just my $0.02... I've heard this discussion too many times.
If you want "fast" bass, pick up a Rythmik Audio subwoofer, or build a low Q sealed enclosure. Or dipole bass, and EQ to taste.
Or to quote a fellow on the forum, if you really want "fast" bass - get a tweeter.
cheers,
-Tal
Re: fast bass
If you are talking the same motor I will agree, that's simple physics. Larger drivers often have much stronger motors and can deal with the added mass. They often have a lower Q than smaller drivers and give you the "tighter" bass. Smaller drivers seem rely on the higher Q just to achieve a desired level of bass. Higher Q means sloppier bass. Heck some even run them OB for goodness sakes.
The larger the cabinet, the less pressurizing of the cavity. If you run an IB cabinet, which is a bit of an oxymoron, ie: minimum 4X the Vas, the panel exciting is much less, no?
bizman said:
If you are talking the same motor I will agree, that's simple physics. Larger drivers often have much stronger motors and can deal with the added mass. They often have a lower Q than smaller drivers and give you the "tighter" bass. Smaller drivers seem rely on the higher Q just to achieve a desired level of bass. Higher Q means sloppier bass. Heck some even run them OB for goodness sakes.
The larger the cabinet, the less pressurizing of the cavity. If you run an IB cabinet, which is a bit of an oxymoron, ie: minimum 4X the Vas, the panel exciting is much less, no?
Would you say that four 15" woofers mounted as dipole could be expected to produce "fast" bass? 0.26Qts, so certainly not high, and naturally requiring electrical compensation due to this. These woofers:
http://www.monacor.de/typo3/index.php?id=84&L=1&artid=2069&spr=EN&typ=full
Also voice coil inductance seems relatively low for such a driver and high frequency response is good, both of which seemed to be mentioned as beneficial. Not sure if moderately high sensitivity is also a plus point for this?
This is what I plan for my system eventually, mounted as a pair of W-Profile dipoles, with room EQ also 🙂😎
http://www.monacor.de/typo3/index.php?id=84&L=1&artid=2069&spr=EN&typ=full
Also voice coil inductance seems relatively low for such a driver and high frequency response is good, both of which seemed to be mentioned as beneficial. Not sure if moderately high sensitivity is also a plus point for this?
This is what I plan for my system eventually, mounted as a pair of W-Profile dipoles, with room EQ also 🙂😎
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