Hi,
It will all end up going round in circles, if you don't really understand
the practical analysis of the problem and the effective solutions.
Vented boxes have more bass end than sealed in hifi, but are typically
twice as big as sealed boxes. Vented music speakers typically have
power handling alignments, boxes not much bigger than sealed
and hardly anymore bass, but can produce more clean SPL
around the port tuning frequency, the lowest note you want.
More to the point is the distortion profile of the drivers, and basically
for drivers that are not intended to be super clean, vented messes
up drivers that progressively distort (react to plucking dymanics).
Too much theory, too much conjecture, not enough experience.
rgds, sreten.
I've played a 4 string tuned to low B. Most hifi's can't reproduce
the low B fundamental nevermind trying to reproduce it live.
The loudest note on a plucked string is the second harmonic.
It will all end up going round in circles, if you don't really understand
the practical analysis of the problem and the effective solutions.
Vented boxes have more bass end than sealed in hifi, but are typically
twice as big as sealed boxes. Vented music speakers typically have
power handling alignments, boxes not much bigger than sealed
and hardly anymore bass, but can produce more clean SPL
around the port tuning frequency, the lowest note you want.
More to the point is the distortion profile of the drivers, and basically
for drivers that are not intended to be super clean, vented messes
up drivers that progressively distort (react to plucking dymanics).
Too much theory, too much conjecture, not enough experience.
rgds, sreten.
I've played a 4 string tuned to low B. Most hifi's can't reproduce
the low B fundamental nevermind trying to reproduce it live.
The loudest note on a plucked string is the second harmonic.
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Solutions
1) To use the existing cabinet (Marshall 4x12 dimensions) for bass guitar, and modified for use with 10 inch drivers, use 4 of these (http://www.parts-express.com/pedocs/specs/290-470-eminence-legend-bp102-4-specifications.pdf) wired series/parallel to get a total 4 ohm impedance. They are the most widely used drivers for high power 4x10 cabinets. There are better, but at much higher cost.
2) To use the existing cabinet (Marshall 4x12 dimensions) for bass guitar and modified for using one fifteen inch driver, use 1 of these (Faital Pro 15PR400 Speakers - Faital Pro 15PR400 bass guitar and PA speaker that has a lightweight neodymium magnet - Faital Pro 15PR400 800 watt high efficiency of 100dB SPL woofer for all mid-bass and bass applications. Faital Pro 15PR400 sp). This is a state of the art driver for this application. It not only has high power, low distortion deep bass, but a smooth response up to 4kHz. The smooth response makes crossover design much easier (note that I didn't say easy).
Tune to 32 Hz using a 2x10x5 7/8 inch vent or two 3 inch diameter, 5 1/4 inch vents.
3) The Eminence Alpha 10 mentioned by Criris is a nice cost effective solution for a sealed 5 cf cabinet like yours. The Alpha 10 is not really unsuitable for vented designs. It will not really provide much energy for the B string fundamentals, but will provide pretty good coverage of them. This is because most of the energy is in the harmonics, especially, as Sreten mentioned. Audio designers discovered long ago that reproduction of the harmonic structure of a bass note, from the second harmonic up, would provide a close illusion of the real thing. Therefore, a cabinet with good response into the 60's usually proves adequate. Most 4x10's provide this (up to very hight spls). The Faital driver (option 2 above) will provide strong output for the fundamentals on the B string at very high spls.
The progressive surrounds are almost universally applied in musical instrument and pro audio bass drivers. They do not affect fidelity until near Xmax. Without a progressive surround, the driver would fairly severely distort: much more than with the progressive surround.
The Tangband driver is an awesome home sub driver, but at only 85db/w/m, it is simply unusable for high spl bass guitar use. Also notice the severe peaking in response above 400 Hz. It would have to be crossed over at least an octave lower (200Hz or lower... like a sub). This is not a limitation for home sub use, but is a deal breaker for bass guitar use.
Use the two Fender Twin 12" speakers in a closed back cabinet of 3-4 cf for a great guitar cab.
Regards,
Bob
1) To use the existing cabinet (Marshall 4x12 dimensions) for bass guitar, and modified for use with 10 inch drivers, use 4 of these (http://www.parts-express.com/pedocs/specs/290-470-eminence-legend-bp102-4-specifications.pdf) wired series/parallel to get a total 4 ohm impedance. They are the most widely used drivers for high power 4x10 cabinets. There are better, but at much higher cost.
2) To use the existing cabinet (Marshall 4x12 dimensions) for bass guitar and modified for using one fifteen inch driver, use 1 of these (Faital Pro 15PR400 Speakers - Faital Pro 15PR400 bass guitar and PA speaker that has a lightweight neodymium magnet - Faital Pro 15PR400 800 watt high efficiency of 100dB SPL woofer for all mid-bass and bass applications. Faital Pro 15PR400 sp). This is a state of the art driver for this application. It not only has high power, low distortion deep bass, but a smooth response up to 4kHz. The smooth response makes crossover design much easier (note that I didn't say easy).
Tune to 32 Hz using a 2x10x5 7/8 inch vent or two 3 inch diameter, 5 1/4 inch vents.
3) The Eminence Alpha 10 mentioned by Criris is a nice cost effective solution for a sealed 5 cf cabinet like yours. The Alpha 10 is not really unsuitable for vented designs. It will not really provide much energy for the B string fundamentals, but will provide pretty good coverage of them. This is because most of the energy is in the harmonics, especially, as Sreten mentioned. Audio designers discovered long ago that reproduction of the harmonic structure of a bass note, from the second harmonic up, would provide a close illusion of the real thing. Therefore, a cabinet with good response into the 60's usually proves adequate. Most 4x10's provide this (up to very hight spls). The Faital driver (option 2 above) will provide strong output for the fundamentals on the B string at very high spls.
The progressive surrounds are almost universally applied in musical instrument and pro audio bass drivers. They do not affect fidelity until near Xmax. Without a progressive surround, the driver would fairly severely distort: much more than with the progressive surround.
The Tangband driver is an awesome home sub driver, but at only 85db/w/m, it is simply unusable for high spl bass guitar use. Also notice the severe peaking in response above 400 Hz. It would have to be crossed over at least an octave lower (200Hz or lower... like a sub). This is not a limitation for home sub use, but is a deal breaker for bass guitar use.
Use the two Fender Twin 12" speakers in a closed back cabinet of 3-4 cf for a great guitar cab.
Regards,
Bob
My thanks to everyone for their input here.
I have looked also at this design, the Ashdown 4x10 Bass Cab (600 watt).
Please notice both the bullet tweeter in the middle of the cab,
and also the PORTS on the back!
It looks like those ports could be estimated,
and might be acceptable for these smaller 10" speakers.
Do you think porting is a good idea in this case,
if I go with the smaller 10" speakers?
Secondly, how deep do you think those ports are?
Finally, why did they port their cab, if a closed cab would be better overall?
Is this just a cheap effect to make the cabinet sound louder?
I have looked also at this design, the Ashdown 4x10 Bass Cab (600 watt).
Please notice both the bullet tweeter in the middle of the cab,
and also the PORTS on the back!
It looks like those ports could be estimated,
and might be acceptable for these smaller 10" speakers.
Do you think porting is a good idea in this case,
if I go with the smaller 10" speakers?
Secondly, how deep do you think those ports are?
Finally, why did they port their cab, if a closed cab would be better overall?
Is this just a cheap effect to make the cabinet sound louder?
Attachments
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Thanks for all the help Bob:
When you say 3-4 cubic feet, which is more ideal, 3 or 4?
And what shape would that take?
Could I for instance have the speakers more or less like they were in the Fender (side by side),
but tilted upward a bit, for the guitarist?
My local speaker shop has offered up a set of 4 10" speakers,
for about $200 and change.
He didn't say what brand (I should kick myself for not asking that),
but said they were designed just for this kind of use,
by a company that also does PA speakers.
They had large magnets, and looked about 50-100 watts each maybe...
Is this sounding like a good deal?
for about $200 and change.
He didn't say what brand (I should kick myself for not asking that),
but said they were designed just for this kind of use,
by a company that also does PA speakers.
They had large magnets, and looked about 50-100 watts each maybe...
Is this sounding like a good deal?
"which is more ideal, 3 or 4 (cubic feet)?"
Probably 4 cf is closer to optimum. Without knowing some key TS parameters an optimum design is not possible. The sides will need to be lined with acoustic insulation. It would be best to use the cabinet with the drivers aligned vertically (not horizontally like the Fender).
The cab should have internal dimensions of 31x17x13 inches.
You can always add supports that allow the cab to be tilted.
That Ashdown 4x10 uses drivers with very specific engineering characteristics. Drivers of the same size can differ substantially in these characteristics and therefore require different enclosure design specifics; sealed or ported, cab volume, tuning frequency if ported, among others. Copying the Ashdown cabs (same cab and port dimensions), but using different 10 inch drivers will result in sound that differs from the original, quite possibly resulting in poor sound quality. The eminence 10 inch drivers I suggested work best in sealed cabinets. The major issue with ported 4x10 cabs is the need to load the drivers down to the lowest frequency they will used for: in this case, low B. Many ported cabs are tuned higher.
Your requirement to reproduce the fundamental for notes on the B string will met by very few drivers (regardless of their nominal diameter), especially in a pre-existing cabinet.
If you return to that shop ask for the model number of the 10 inch drivers he offered you.
Regards,
Bob
Probably 4 cf is closer to optimum. Without knowing some key TS parameters an optimum design is not possible. The sides will need to be lined with acoustic insulation. It would be best to use the cabinet with the drivers aligned vertically (not horizontally like the Fender).
The cab should have internal dimensions of 31x17x13 inches.
You can always add supports that allow the cab to be tilted.
That Ashdown 4x10 uses drivers with very specific engineering characteristics. Drivers of the same size can differ substantially in these characteristics and therefore require different enclosure design specifics; sealed or ported, cab volume, tuning frequency if ported, among others. Copying the Ashdown cabs (same cab and port dimensions), but using different 10 inch drivers will result in sound that differs from the original, quite possibly resulting in poor sound quality. The eminence 10 inch drivers I suggested work best in sealed cabinets. The major issue with ported 4x10 cabs is the need to load the drivers down to the lowest frequency they will used for: in this case, low B. Many ported cabs are tuned higher.
Your requirement to reproduce the fundamental for notes on the B string will met by very few drivers (regardless of their nominal diameter), especially in a pre-existing cabinet.
If you return to that shop ask for the model number of the 10 inch drivers he offered you.
Regards,
Bob
Theil/Small parameters
Hi therere N: Don't "kick your self", just call the dealer and ask for the Brand, model numbers, and T/S parameters. It is not posible to "design"( using computer programs or design tables) an adequate speaker enclosure with out the T/S parameters. You might get lucky by guessing a box size, however, as others have written here, you may have wasted your time and resources. For some of the drivers (speakers) recommended by others, you can find the T/S provided by the manufacturers by Googling them on the net, (or checking your existing drivers with appropreate instruments, and the dealer may also be able to do this with the no name brand drivers)... regards, Michael
Hi therere N: Don't "kick your self", just call the dealer and ask for the Brand, model numbers, and T/S parameters. It is not posible to "design"( using computer programs or design tables) an adequate speaker enclosure with out the T/S parameters. You might get lucky by guessing a box size, however, as others have written here, you may have wasted your time and resources. For some of the drivers (speakers) recommended by others, you can find the T/S provided by the manufacturers by Googling them on the net, (or checking your existing drivers with appropreate instruments, and the dealer may also be able to do this with the no name brand drivers)... regards, Michael
Forget about 4 x 10 or 4 x 12 if you want it to go low. All you really need is a single 15" in a ported cabinet for your needs. I recommend the Eminence Kappa 15, regular not pro. I made a bass cabinet with one. It actually works quite well for quitar as well because the Kappa 15 has a big breakup (presence... ) peak. Put it in about 6-7 cu ft and tune to Fs. I recommend an ML-TL type box approx 36-39" tall, to get a little extra midbass punch. Duct/shelf port at the bottom. It will reach 30hz, but at ~f10. Room gain will likely improve this.
I wouldn't attempt to operate a resonant enclosure at f10 - by then, the cone will be fully unloaded. Room gain will not fix this, but you would be likely to mechanically damage the driver once things were turned up.
f10 = the frequency that's 10dB down from nominal efficiency.
Check out the excursion charts of ported boxes - you don't want to go below tuning.
ML-TL is a Mass Loaded Transmission Line. Not my area of expertise...
Chris
Check out the excursion charts of ported boxes - you don't want to go below tuning.
ML-TL is a Mass Loaded Transmission Line. Not my area of expertise...
Chris
Hi,
Like I said most ported musical speaker boxes are for power handling,
not extension, and should be tuned to or slightly above the lowest note.
With twin ports tuned to low E, you can block one to tune for low B.
rgds, sreten.
my 4x10 guitar cab.
ive made my own cab using a old hartke 4x10 basscab replacing drivers with celestion g10r greenbacks. The cab uses a 4inch port tube. I blocked it. Guitar drivers with an fs of 80hz arent going to get down to 30hz without help, and probably a full cab volume PER SPEAKER. in short HUGE.
ive made my own cab using a old hartke 4x10 basscab replacing drivers with celestion g10r greenbacks. The cab uses a 4inch port tube. I blocked it. Guitar drivers with an fs of 80hz arent going to get down to 30hz without help, and probably a full cab volume PER SPEAKER. in short HUGE.
F10 has nothing to do with this. The Fs of the driver I recommended is 33. It should not be tuned below Fs.
BTW tuning below Fs can be and is done, and the driver doesn't automatically explode. That said, it's still not a good idea for a musical instrument driver, as power handling will suffer.
You guys have all been great!
This has been the most informative speaker thread I've had
the privilege of reading (hope I haven't started any feuds either!).
As one more possibly cost-effective solution,
I tripped over this seemingly too-good-to-be-true offer for 12" guitar speakers:
$139 for FOUR celestions, with free shipping! (to USA)
Celestion Rocket 50 Guitar Speaker at AmericanMusical.com
This does seem inexpensive, do you think its a good deal, or can I do better?
What if I only used TWO of four: would they make good bass speakers,
given that each would have about 2.5 cubic feet in the box?
Suppose in other words, I built two boxes, and put two in each.
Or alternately, I could go halves with someone,
so that we each got two at $70!
I have heard that Celestion is a good speaker,
but are these real ones, or something else?
They are advertizing them as guitar speakers...
----------------------------
Update:
I also found a Four Pack of 10" Celestion Tube 10 guitar speakers,
for 78 pounds (about $126.00 Canadian) but shipping is unclear:
http://www.lean-business.co.uk/esho...8ohm-10-guitar-speaker-bundle-pack-p-297.html
Looks like it might be a good deal if the shipping isn't out of control..
But can these do bass? I know that Celestion also has actual bass speakers,
and I wonder if there is something to the difference, e.g., power handling, heat dissipation, or some other factor like Fs.
I can't seem to get specs on the actual models from the sellers...
This has been the most informative speaker thread I've had
the privilege of reading (hope I haven't started any feuds either!).
As one more possibly cost-effective solution,
I tripped over this seemingly too-good-to-be-true offer for 12" guitar speakers:
$139 for FOUR celestions, with free shipping! (to USA)
Celestion Rocket 50 Guitar Speaker at AmericanMusical.com
This does seem inexpensive, do you think its a good deal, or can I do better?
What if I only used TWO of four: would they make good bass speakers,
given that each would have about 2.5 cubic feet in the box?
Suppose in other words, I built two boxes, and put two in each.
Or alternately, I could go halves with someone,
so that we each got two at $70!
I have heard that Celestion is a good speaker,
but are these real ones, or something else?
They are advertizing them as guitar speakers...
----------------------------
Update:
I also found a Four Pack of 10" Celestion Tube 10 guitar speakers,
for 78 pounds (about $126.00 Canadian) but shipping is unclear:
http://www.lean-business.co.uk/esho...8ohm-10-guitar-speaker-bundle-pack-p-297.html
Looks like it might be a good deal if the shipping isn't out of control..
But can these do bass? I know that Celestion also has actual bass speakers,
and I wonder if there is something to the difference, e.g., power handling, heat dissipation, or some other factor like Fs.
I can't seem to get specs on the actual models from the sellers...
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Okay, this makes sense:
So the porting idea really isn't for bass, I take it,
unless it is carefully chosen to match speakers.
I also get the sense that the port should be tuned at or higher than the Fs of the speaker(s).
Does using two speakers in one box change the Fs? (e.g. halve it?)
How would one choose a port for a given set of 4 10" speakers?
Or should this be avoided for bass?
This sounds like a great option!
Suppose I built a hatch, so that you could have two ports for regular bass,
then when playing a 5-string, you just close a stiff air-tight hatch on the back?
Is this sensible, or is there a danger-factor?
Okay if you listen to the bottom end of this,
it sounds pretty clean and solid, yet tight.
I think the upper mids are a bit muddy,
maybe soft, but the low end (through the poor quality video)
seems okay:
Billy Sheehan - Bass Solo - YouTube
I'm looking for clarity and flatness in the bottom 2 octaves.
it sounds pretty clean and solid, yet tight.
I think the upper mids are a bit muddy,
maybe soft, but the low end (through the poor quality video)
seems okay:
Billy Sheehan - Bass Solo - YouTube
I'm looking for clarity and flatness in the bottom 2 octaves.
This was the bit I was referring to.
I said nothing about tuning below Fs. As you say, can be done, but not wise for high power applications.
Nazaroo, do not buy those guitar speakers.
As I've said before, guitar speakers will not give you the bass guitar sound you desire.
Typically, Fs = 80Hz, Xmax = 0.5mm
So, there will be little output below 80Hz, and the speakers will run out of travel very quickly (ie, more distortion from the driver on lower notes).
Not a good choice for bass guitar
The blockable port option will work, I've contemplated such myself to improve the low end power handling on my 4x10. Make sure the hatch will lock into place and will not come loose.
As Sreten said, tune for power handling - go for slightly above the lowest note that's going to go through.
Ports add more output around a fairly narrow frequency range. They also reduce the speaker's excursion at the frequencies it's boosting.
The down-side is the cabinet needed is much larger than for sealed, leading to an ugly-looking response if the cabinet is too small (hint - they always are: this is the nature of high efficiency drivers). If you have a graphic eq at your disposal, then going for ported and making some attempt to flatten the response makes sense.
If you don't have a graphic eq, then a sealed cabinet will give a response that's immediately usable - they tend to roll off nicely, with minimal peaking in the response (unless its really stupidly undersized).
You say you want 30Hz extension, but I honestly don't think that's a good idea. As people have said before, having content right at the bottom end just tends to muddy the sound. Going for the 2nd harmonic (62Hz, up from 31Hz) is a much easier target for the system as a whole. This is a personal preference for sound - have you tried a bass rig that will go that low?
Chris
Do you have any other sounds you'd like to achieve?
The bass solo you posted didn't have much low end in it.
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