5ft3 4x10 cab: Tune for fundimental or 2nd harmonic?

[Rafael]

So I've been plugging various info into WinISD [looove it!] and with my driver selection I can tune the approximately 5 cubic foot cabinet either to around 40Hz or 61Hz:

WHen tuned for 40 the bottom end slopes off gradually with -3dB point at the 2nd harmonic of low E but the fundamental is down about 10dB

When tuned for 61 the cabinet is essentially flat to 60Hz but down 14dB+ at 40Hz.....

So, my question is, given this is a 4x10 cab and certainly not "hi-fi" down to 20Hz, what's the preferred tradeoff? flat thru the 2nd harmonic or more gain down under? I think eq-ing +3dB at 80Hz is easier than bringing up the fundamental with eq, but am I just chasing chimera trying to get the most gain at 40Hz?

[DukeLeJeune]

The first overtone is perceptually more important than the fundamental, but also look at excursion-limited power handling. You may well find that tuning in the mid to upper 40's is a better all-around choice.

[billfitzmaurice]

Originally Posted by DukeLeJeune

The first overtone is perceptually more important than the fundamental, but also look at excursion-limited power handling. You may well find that tuning in the mid to upper 40's is a better all-around choice.

+1. Also try a larger box. Most tens are happiest with 1.5 to 2 cu ft each. That makes a pair of 2x10s a much easier haul than a 4x10, and also allows having the drivers vertical. The midrange response of tens is squandered away when you place them horizontally.

[jokerjkny]

these are the threads where talkbass pays for itself.

[will33]

+1 to all the above. I'm curious what 10's you're using, most I've seen in that size box and 60hz tunings result in a much larger hump than your blue line shows.

[Rafael]

Originally Posted by will33

+1 to all the above. I'm curious what 10's you're using, most I've seen in that size box and 60hz tunings result in a much larger hump than your blue line shows.

I ran those simulations with Eminence DeltaLite 2510s. Due to budget constraints I'll probably wind up running Basslites in the cab.

To address another post: Bill, in the long run I'm working on composite-construction 2x10 cabs, but in the short term I have drivers and some old Peavey PA cabs that are about 30x24x18 that are plywood and not particle board that I'm converting to 4x10 use in the meantime....and w/ neo drivers should weigh about half of the conventional magnet/particle board cab I'm currently using....

It's fun reading about some peoples neato rigs that cost $$$$$$ but I'm doing this on the cheap. My biggest investment EVER on bass gear is my new Carvin BX500. Everything else I've used over the last 30 years of playing has been bargain-basement stuff.

[will33]

IMO, I'd consider basslites to be the better choice regardless of the price difference. I haven't modeled much recently with the 10's but the 12's have good lowend performance, are a little smoother in the mids and will play a little deeper in the same size box as compared to the deltalite's....or can play just as low in a slightly smaller box, however you look at it. New computer here, old one crashed so I can't pull up any models yet. Going from memory here.

[bgavin]

Originally Posted by DukeLeJeune

The first overtone is perceptually more important than the fundamental...

I disagree.

Take an active crossover system such as the DCX2496 and set a 48 db/octave filter to high pass at 82 Hz.
This will cut out the fundamental entirely, leaving the 2nd harmonic and higher.

If you like the sound, the fundamental is not important to your ears.
If you find the sound to be thin, anemic, and wimpy then the fundamental is very much important to your ears.

FFT Analysis of my four 4-string basses shows the amplitude of the fundamental to be equal or even slightly stronger than the 2nd harmonic.
The period for the fundamental is brief compare to the 2nd harmonic, so it accumulates much less energy under the curve.

The above chart is a DP146 pickup on a MIM p-bass, e-string plucked.

[billfitzmaurice]

Originally Posted by Rafael

I ran those simulations with Eminence DeltaLite 2510s.

If you let WinISD do it for you it tells you the 2510 works best at 2.1 cu ft tuned to 50 Hz. I assume you mean Deltalite II and not the original Deltalite, which is totally different and not nearly as good a driver. S2010 models flattest at 1 cu ft /46 Hz, but works a lot better in 2 cu ft. It still isn't the equal of the 2510 though.

[DukeLeJeune]

Originally Posted by bgavin

I disagree.

Take an active crossover system such as the DCX2496 and set a 48 db/octave filter to high pass at 82 Hz.
This will cut out the fundamental entirely, leaving the 2nd harmonic and higher.

If you like the sound, the fundamental is not important to your ears.
If you find the sound to be thin, anemic, and wimpy then the fundamental is very much important to your ears.

FFT Analysis of my four 4-string basses shows the amplitude of the fundamental to be equal or even slightly stronger than the 2nd harmonic.
The period for the fundamental is brief compare to the 2nd harmonic, so it accumulates much less energy under the curve.

The above chart is a DP146 pickup on a MIM p-bass, e-string plucked.

Bgavin, I don't think your experiment would put my claim to the test because it doesn't compare the audibility of the fundamental against the audibility of the second harmonic.

Very interesting that the peak amplitude from your basses of both fundamental and second harmonic are roughly equivalent. Thanks for sharing that information.

Equal-loudness curves indicate that the second harmonic will be more audible. And the short duration of the 41 Hz fundamental works against its audibility; sounds that are of short duration are perceived as softer that those which last longer and/or decay more slowly.

[AlexanderB]

+ 1 to bgavin. I completely agree. And I have never had a problem (gigging or just rehearsing) with bottom end being overbearing or too boomy.

/Alexander from Sweden

[AlexanderB]

The 2510 series II is an OK driver that I use two of in an upgraded EBS Proline cab ( which actually is too small for these drivers). As you have noticed, they generally do not work very well for deeper cabinet tuning. (Hardly any Eminence drivers do...) I have tried different tunings and found out that they (or actually I...) are happiest tuned a bit below 50Hz, as a compromise between loudness, excursion and extension.
A narrow band EQ can flatten the response and make it rather flat down to 40-ish at the expense of max SPL.

2510 II mids and highs are quite nice, though.

/Alexander

[bgavin]

Originally Posted by DukeLeJeune

Bgavin, I don't think your experiment would put my claim to the test because it doesn't compare the audibility of the fundamental against the audibility of the second harmonic.

My design requirement is for the cab to faithfully reproduce as much of the signal as possible.
This includes not discarding the bottom octave.

Note that not every bass cab is used for electric bass.
Keyboards and synthesizers do not suffer the limitations of stringed instruments, and therefore produce the fundamental across all notes.

For example, a synth baritone sax played through a 2nd harmonic cab does get the general idea across.
The synth baritone is much more authentic with its full bottom intact.
Ditto for Hammond, pianos, and synth electric bass.

OP, you have to move a lot of air to have authority at 40 Hz.
As Bill notes above, a 10" needs sufficient cabinet volume to reach its potential.
The BP102 requires some 4 cubic feet (each) to reach down to 31 Hz.
The 2510-II has an F3 at 50 Hz, and S2010 is 67 Hz.
Beta 10a has an F3 of 40 Hz, but a wimpy xmax.
Delta 12LFa has an F3 at 41 Hz, but still requires 4 cubic feet.

OP, my advice is skip the 10" entirely and opt for a 3015LF in your 5 cubic foot cab.
The price difference between one 3015LF and four 10" will be very close.
This will far outperform a typical 10" group and give an F3 at 41 Hz.
You can sub-chamber an Alpha 6a or similar for the required mid-range driver.
This is the fEarful concept. It produces a smooth response and works well.

[BogeyBass]

Originally Posted by Rafael

I ran those simulations with Eminence DeltaLite 2510s. Due to budget constraints I'll probably wind up running Basslites in the cab.
Everything else I've used over the last 30 years of playing has been bargain-basement stuff.

Come on man..if you have been playing bass for 30years, it obvious that your not going to stop. and if you have been playing with bargain stuff all that time.....its time to take a kick in the pants and invest in a expensive set of drivers.

Otherwise their is hundreds of used prebuild boxes loaded with cheap drivers. that would sound the same and be cheaper to just buy.....which of course spoils they whole fun part of building something yourself....SO

Invest in a high quality driver......then invest your time building a high quality enclosure around it. You can make everything look pretty on a computer screen. But in the real world when dealing with Low frequencies, a larger box and a high quality driver will always sound better than a cheap driver in a small box.

otherwise as far as the tuning topic, im gonna throw this out to the experts. IF the goal of a design is to build a small box. Its already obvious that airspace is a issue. so we add a port to let it breath. now the question is tune the port to 40 or 60hz. seems like you would look at the drivers resonant freq right?
or simply look at the weakest point of the drivers impedance curve? the DeltaLite 2010 shows to be almost 65 ohms at 50hz.
So if you tune the port to a freq that the speaker will most likely never produce. you would reduce the odds of creating unwanted peaks or boomy notes, because the driver is unable to produce frequencies that the port is tuned too. So 65ohms at 50hz i would say forget about ever hearing that freq. So if we "tune" the port to 50hz it basically just turns it into a "untuned" hole to allow more air to pass. which is the point anyways right? to let more air into a box thats too small in the first place. Probably just a bunch of BS on my part, atleast it sounded good since WinISD seems to recommend 50hz for a deltalite 2010. which is close to its (Fs) of 53hz which is close to its huge 65ohm impedance peak. Everyone talks about "tuning" as if it increases frequency response. It doesn't increase anything. it just allows the driver to create what its capable of doing when stuck inside a airspace thats to small.
A 95dB speaker will always be 95dB...its freq response can only get worse not better....and will always be limited by what the driver can do physically. cheap low dB speakers never pay off in the end, no matter what a computer graph tells you.

don't forget what my mama said "practice makes perfect"

[alexclaber]

Originally Posted by BogeyBass

Come on man..if you have been playing bass for 30years, it obvious that your not going to stop. and if you have been playing with bargain stuff all that time.....its time to take a kick in the pants and invest in a expensive set of drivers.

Otherwise their is hundreds of used prebuild boxes loaded with cheap drivers. that would sound the same and be cheaper to just buy.....which of course spoils they whole fun part of building something yourself....SO

Invest in a high quality driver......then invest your time building a high quality enclosure around it. You can make everything look pretty on a computer screen. But in the real world when dealing with Low frequencies, a larger box and a high quality driver will always sound better than a cheap driver in a small box.

100% right!

Originally Posted by BogeyBass

otherwise as far as the tuning topic, im gonna throw this out to the experts. IF the goal of a design is to build a small box. Its already obvious that airspace is a issue. so we add a port to let it breath. now the question is tune the port to 40 or 60hz. seems like you would look at the drivers resonant freq right?
or simply look at the weakest point of the drivers impedance curve? the DeltaLite 2010 shows to be almost 65 ohms at 50hz.
So if you tune the port to a freq that the speaker will most likely never produce. you would reduce the odds of creating unwanted peaks or boomy notes, because the driver is unable to produce frequencies that the port is tuned too. So 65ohms at 50hz i would say forget about ever hearing that freq. So if we "tune" the port to 50hz it basically just turns it into a "untuned" hole to allow more air to pass. which is the point anyways right? to let more air into a box thats too small in the first place. Probably just a bunch of BS on my part, atleast it sounded good since WinISD seems to recommend 50hz for a deltalite 2010. which is close to its (Fs) of 53hz which is close to its huge 65ohm impedance peak. Everyone talks about "tuning" as if it increases frequency response. It doesn't increase anything. it just allows the driver to create what its capable of doing when stuck inside a airspace thats to small.
A 95dB speaker will always be 95dB...its freq response can only get worse not better....and will always be limited by what the driver can do physically. cheap low dB speakers never pay off in the end, no matter what a computer graph tells you.

100% wrong!

Originally Posted by BogeyBass

don't forget what my mama said "practice makes perfect"

100% right!

[billfitzmaurice]

Originally Posted by BogeyBass

simply look at the weakest point of the drivers impedance curve? the DeltaLite 2010 shows to be almost 65 ohms at 50hz.

Absolutely totally irrelevant.

Probably just a bunch of BS on my part

Spot on.

[staindbass]

would it be possible to build the cab with a tuneable port ? sliding duct/vent ect? i would be more comfortable choosing by ear. i will bet the 60 hz will sound better to you and dont forget the free 3db of output. johnny a.

[BogeyBass]

Originally Posted by bgavin

OP, my advice is skip the 10" entirely and opt for a 3015LF in your 5 cubic foot cab.
The price difference between one 3015LF and four 10" will be very close.
This will far outperform a typical 10" group and give an F3 at 41 Hz.
You can sub-chamber an Alpha 6a or similar for the required mid-range driver.
This is the fEarful concept. It produces a smooth response and works well.

I would agree that a 15" is better for bass then a 10" the smallest I would go with is a 12"

Come on people...a guitar is one octave higher than a bass and the standard guitar speaker is 12"

So why would you use a smaller 10" speaker for bass thats one octave lower?

A 3015LF in 5cu ft is going to need a large port its (vas) is at 5.6 cu ft and would probably be much better in a larger enclosure. A standard guitard cabinet is close to 29" square and 15" Deep which is about 7cu ft. A good stage bass cabinet would be at least 8 to 10cu ft with the standard 2 x 15" drivers...and still have a port to keep everything happy. the huge 9.6mm xmax of the kappa3015LF drys up any hopes of decent high end. At 60Hz its barely at 90dB and the real range of the speaker is around 100 to 1.5K which is a more realistic 97 to 98 dB instead of the claimed 99db. The 3015 has a xmax of 5.9mm and its high end extends to about 3k. The rated 100dB actually holds up pretty well. 60hz response is the same actually its 1dB higher at 91db. The high end is twice as high at 3K than the LF 1.5k . Most likely the Kappa lite 3015 would do much better in a small 5cu ft enclosure and would work just fine in fullrange. opposed to the LF which would rather see a crossover and a much larger enclosure.

[bgavin]

Originally Posted by BogeyBass

A 3015LF in 5cu ft is going to need a large port its (vas) is at 5.6 cu ft and would probably be much better in a larger enclosure.

There is no need to guess.
The 3015LF requires a port diameter of 7.62" to achieve 0.045 MACH vent velocity at maximum displacement.

A net internal volume of 5.02 cubic feet is required for the Flat alignment.
This can be reduced to 3.83 cubic feet for the BB4 alignment, if one is willing to trade bottom octave response for smaller size.
An enclosure larger than 5 cubic feet is an EBS-type, with the corresponding trade-offs to achieve a lower bass response.

As I noted above, the 3015LF is a nice combination with a mid-range driver.
The fEarful charts I've seen show this to be a very useful combination.

3015LF is omni-directional up to 257 Hz, and is fully directional (beaming) above 1028 Hz.
This is useful only if playing to your knees.
Otherwise, it is thuddy off-axis and laser beam shrill on-axis.
3015LF is a woofer, and has no useful output above 1 KHz.

Scope analysis shows the typical electric bass has audible harmonics up to 7KHz or so. Slaps and clanks probably go higher.
The typical 6" driver (Alpha 6) is good to 5 KHz, and only a few dB down at 7 KHz.
Beaming begins at 670 Hz and is fully beaming above 2678 Hz.
A tweeter is required for wide angle high frequency dispersion.
I prefer two Alpha 6c in series as a 2:1 voltage divider sufficient to protect them from the 60v maximum input to this design.

Volt per volt, the two 6" are -5dB down from the 3015LF output.
Bi-amping is the solution.
There is more to it than plugging numbers into WinISD.

[Rafael]

Originally Posted by bgavin

OP, my advice is skip the 10" entirely and opt for a 3015LF in your 5 cubic foot cab.
The price difference between one 3015LF and four 10" will be very close.
This will far outperform a typical 10" group and give an F3 at 41 Hz.
You can sub-chamber an Alpha 6a or similar for the required mid-range driver.
This is the fEarful concept. It produces a smooth response and works well.

The thing is my ultimate plan is to build a few 2x10 ZacLite cabs [labor intensive but light weight] and I currently run a Behringer 4x10 @100#+ so in the meantime I have two 5 cubic foot plywood boxes [fairly light compared to particle board] already carpeted/cornered/handled/etc. that I thought I could stuff my 10s into until the glass work gets done, saving my back in the meantime.

The funny thing is everyone comes at this from a different perspective, and of course every design is a tradeoff, but there are those who swear by 115s, others who swear by the 410, I've asked around about the deltas -v- basslite and gotten both answers....in the real world there is no perfect cabinet [yet] but all the responses I'm seeing are food for thought. Thanks for your input.