Playing hornresp : 22L tapped horns 30-180hz with 10" speaker

[papasteack]

Hi,

I know search for optimal mini sub is well talked on the web. I've read all i can find...But most of time, it is for max spl. I think tapped horn can be also use to get very small cabinet with very flat frequency from 20 to 200hz. It would not be efficient, but it would be to use at low level at home, only for bass playing. I cannot access to picasa to upload images, so i'll have to explain.I can't post now hornresp simulations.

First, i made simulation with all tang band speakers from 2 4" wich was not so bad, to 8"...i tryed with some B&C speaker (10nw64,8nw81,8fg51)...But as i can go 4ohm, it's not so much optimal until i get a 4 ohm speaker, or 2 8 ohm. I've tested with some 18sound, some sica, seas, and some ciare pro, faital. And that here i discover ciare public range speakers... the cw258nd is a 10" 4 ohm speaker with a very low VAS.

In a 5 segment tapped in only 20 liters it reach a near flat response from 30 to 180 hz with a group delay of 20ms @30hz (not so bad) at 92-94 db @1pi space (nead a wall). With 12 watts, it make 100 db. Diaphragm displacement is only 2,5mm...far from the 9 mm xmax. The impulse response is bad, but as it only for sub...i don't know if it really matter.
I choose first this speaker because it the only 10" 4ohm speaker with a VAS near 20 without going for rubber surround.
His xmax limit would be reached at 100w, and it would push 110 db.
After all, if finally it is possible, it should maybe realized in a kind of Bill Fitzmaurice Jack10 like this Another Jack 10 build - Page 2 - finnbass.com ; It is a interesting way to do a cubic tapped horn and seems to work well.

As it's only numbers for me, does 100-110 db in a 1pi space seems you "enough" ?
There would be a active crossover in the 180 range to mix with a guitar cabinet used as "medium-high" speaker. The idea is to have practice bass, and guitar cabinets, in the smallest volume possible keeping good lows. A small tda chip amp would run the low (and maybe after something bigger) and a 1w SE UL ECL82 for the medium/high.

I need your help because it's only simulation. I tryed to do the best i understood from what i've found on the web. But it would be the first time i try tapped horn.

Did i misunderstand something ?
Does it seems you a interesting ?
Any suggestion ?

Just for fun i tryed something else...It seems too that the guitar speaker eminence governor 16 ohm in his 30L closed box should get near the same response in a 15L tapped horn (very hard to make, but seem possible). As it's for guitar, resonnance, and distortion is not so much a problem. It could be great, or bad.... But i'm really not convinced...

 

[papasteack]

[IMGDEAD]https://lh5.googleusercontent.com/-WynHCr1rfGc/UR_oTMTRpiI/AAAAAAAAAUs/AilF-KzQhPI/s512/hornresp.png[/IMGDEAD]
I've lost my optimised test, but it was not so far from somthing like this...

 

[weltersys]

As it's only numbers for me, does 100-110 db in a 1pi space seems you "enough" ?
There would be a active crossover in the 180 range to mix with a guitar cabinet used as "medium-high" speaker. The idea is to have practice bass, and guitar cabinets, in the smallest volume possible keeping good lows. A small tda chip amp would run the low (and maybe after something bigger) and a 1w SE UL ECL82 for the medium/high.

Did i misunderstand something ?
Does it seems you a interesting ?
Any suggestion ?

Is 110 dB in 1pi enough? Not for most bass players used to playing with drummers- a hard hit on a snare drum can do around 125 dB at one meter. A 10 dB change in level at 1000 Hz sounds twice (or half) as loud.

It would be enough for practice volume for me, but I don't like loud volume. I have my 5 watt Epiphone Valve Jr. practice amp attenuated about 10 dB (equivalent to 1/2 watt output) it will only do 100 dB flat out at one meter measured on the floor.

Counting on boundary loading is generally not a good idea, better to use half space in your figures.

You will want to delay the top cabinet by approximately the path length of the TH for proper integration, otherwise the low bass will seem "slow".

Hornresp generally exaggerates peaks and dips, the little 35 Hz bump may not happen at all, at any rate your small room response will look nothing like the chart anyway.

 

[tinitus]

As it's for guitar, resonnance, and distortion is not so much a problem.

oh, I find it quite the opposite...makes a whole lot of difference

for guitar ? you mean bass guitar ? why do you need 20hz ?

but you dont need a sub at all
think 2-channel amp instead
you can use any PA power amp
and a 2 channel preamp output splitter from preamp

a big PA woofer that goes low in one channel, and playing 'fullrange', and no other driver in that channel
and in the other channel, a 2way stage floor monitor with less low end extention

and you can create a very nice sound by mixing the two channels, turning them up or down

if its not loud enough...just double up

 

[weltersys]

for guitar ? you mean bass guitar ? why do you need 20hz ?

The low B on a five string bass is 30.86 Hz, only 1/3 octave above where papasteack's simulation drops off.

Slapped bass strings have output down to a few Hz, can make a 26" kick drum seem anemic by comparison when reproduced well.

 

[tinitus]

ah, ok, I understand
very low bass 5 string sounds like very good for big places
well, Im more to the smaller stuff

 

[papasteack]

Ok...First, it seems to confirm 100db is what i want. I've played with a lm386 with the eminence governor in a closed box and at around half volume it was what i'm looking for.
In a 2pi space, "lows" would be at 95db ...but does it make a huge difference @30-180 hz ? would 95db be enough at bedroom level ? with loudness effect, it seems complex to me. With 100w, the tapped horn simulation in a 2 pi space give me 103 db...So, the project seems realist, it's a very good news !


I don't need 20hz...and I don't need so much 30hz neither, but i want it as it seems possible, at least to get the small fondamental of a low B when playing bass if i achieve this project a day...

From what i read, a bass sound is essentially harmonics...it's psychoacoustic.

Thanks for the comments. I thought about the problem of phase. As i have to do an active crossover, maybe i can do a phase control. But it's seems very complex thing. It seems to be the biggest problem with this bi-amping. I think simulating on left/right computer audio chanel the crossover should help.

It would only be bi-amped for bass. For guitar, a switch puts off the low amp and the crossover. It's a full system project with all integrated in the smallest enclosure possible...
In the market, "bedroom amp" just never go such low...or become really bigs. And we need a amp for guitar, another for bass... That's why i want to try to use the guitar speaker as mid-high speaker when playing bass. And the idea of tube for high, class D for lows make it more exciting.

Does the idea of putting a guitar speaker in a tapped horn is a bad idea? the simulation looks like the one in a closed box but in a really smaller box...

 

[tinitus]

forget all about crossovers...and 'audio' theories
crossovers really turns instrument speakers into a complete mess
it can really screw up your tuning and pitch

sounds like you want your setup to do both bass and guitar
well, its easy
like I suggested

use 2-channel/stereo setup
a hefty woofer in one channel, running fullrange
and your favourite guitar speaker in the other channel

many 2-channel PA power amp have seperate mono volume pots
so it will be easy to mix the channels as you please

all the other stuff, forget it

 

[weltersys]

In a 2pi space, "lows" would be at 95db ...but does it make a huge difference @30-180 hz ? would 95db be enough at bedroom level ? with loudness effect, it seems complex to me. With 100w, the tapped horn simulation in a 2 pi space give me 103 db...So, the project seems realist, it's a very good news !

From what i read, a bass sound is essentially harmonics...it's psychoacoustic.

Thanks for the comments. I thought about the problem of phase. As i have to do an active crossover, maybe i can do a phase control.

Does the idea of putting a guitar speaker in a tapped horn is a bad idea? the simulation looks like the one in a closed box but in a really smaller box...

Most "guitar speakers" wont have the right parameters for a TH.

From an equal loudness contour standpoint it takes about 119 dB for 30 Hz to sound as loud as 100 dB does at 1000 Hz.

As far as response, a rolled off bottom is OK for bass guitar, but getting the low B to sound full and not make the speaker flap is enjoyable.
Most electric basses the harmonics are already much higher than the fundamental.

What works really depends on style, a system for reggae would need more bottom than for jazz.

Getting phase to match at the crossover point is very important to get "punch" and definition. It often takes using different filter types, and different crossover frequencies between low and high, as well as delay to get it just right.

Done right, a crossover is undetectable, poorly implemented, they can be a mess.

 

[papasteack]

Thanks weltersys. So i'll keep the guitar speaker in his "big" 30L closed cab.

Tinitus, i have already done 300w bi amplified with a 18" bass speaker and a 12" in nearly 100/300 L bass reflex with a old crate bass thunder wich intergrate crossover and a PA amp. It worked REALLY great. At the modest studio, everybody was impressed by big lows. So i don't worry.

 

[tinitus]

well, in my book even a subtle change on a tone control can influence your tuning pitch

I find a fat tone boring, and too slow
adding electronic growl is not my thing either
making it sound like acoustic double bass is the top
so we may not look at it quite the same way

cheers, and good luck

 

[papasteack]

When you ear a record of double bass, it is played by your hifi system that contain crossovers. Bass is not a all the same as electric guitar. Bass is often played in concert connecting DI to pa...wich is often two or more ways. Yourself talked about PA...
We, or at least i do not want too much the speaker to add too much coloration (harmonics...) for bass. Lows are yet difficult to reconize. Whereas for guitar speaker have very low xmax and biggest xlim to add harmonic content. So 12" guitar speakers seemq to be able to sound very high when playing. Same as tube.amp triodes adds harmonics... For bass, crossovering, the sub can work on his low range without trying to do subtiles movement compared to really bigs plus harmonics of those bigs. But this is only words, i have read a lot too. And I ve tryed bi amping. It just worked very fine until the 18" have been played to hard and getted very bad. Probably going to far over xmax. I didn t have a high pass. It was a big error.
Now i want to try a different mini beast... Tapped horn make me very curious.
See bill fitzmaurice cabinets. Horns are already well used for basses by a lot of people. The only difference is that i prefer active crossover than passive. (diy active crossover of course)

 

[tinitus]

When you hear a record of double bass, it is played by your hifi system that contain crossovers.

reproducing a double bass I have always found very difficult

a hifi 8" fullrange in a quaterwave will be very hard to beat, when it comes to that
many many multiways have failed, especially on this matter

if you want to be louder, or have problems 'getting throug', or its difficult for you to hear what you are playing, try gently roll off low bass instead
the cleaner sound cuts through like a knife in butter
very good for playing faster, but all playing errors are also clearly heard

ofcourse it can be done with SPL force
tried it, and it almost made my ears bleed
couldn't hear a thing for several weeks

 

[papasteack]

Look at a sinusoidal with both lows and high...to play big waves amp and speakers compress high. Look at signal...That s why you.roll them off to get clean mid and high...the other(better but harder) way is to separate the signal. So signal of highs and mid is flatter, cleaner...it s not only about speaker , but amp and preamp too... And you ll need less watt !
If you want a double bass sound...buy a double bass. It will always work better. I have never heard a bass sound like a good double bass...
Here i don t want high spl...but lows (real and clean ) at bedroom level is already hard to push... don t forget the effect of loudness at low volume you need more db.at.lows and high to get the same impression. As stated before, in thoqes conditions a.flat reqponqe is a minimaum... (sorry i post from phone ...)

 

[tinitus]

If you want a double bass sound...buy a double bass.

good point but that is a very difficult instrument...electric bass is faster

 

[weltersys]

We, or at least i do not want too much the speaker to add too much coloration (harmonics...) for bass. Lows are yet difficult to reconize. Whereas for guitar speaker have very low xmax and biggest xlim to add harmonic content. And I ve tryed bi amping.
It just worked very fine until the 18" have been played to hard and getted very bad. Probably going to far over xmax. I didn t have a high pass. It was a big error.
Now i want to try a different mini beast... Tapped horn make me very curious.

Just like a FLH, you will need to delay the top cabinet to line up a TH.
Other than that, the TH should sound punchier than a BR, and can be tuned very low in small cabinets using small speakers.

I have measured BR and FLH distortion, below FB/FC distortion can exceed 100% (the harmonics louder than the fundamental) with really small level input, like 10% of rated output.
Designing the Fb to be at your lowest note is a good idea, but don't worry if the response curve is rising (or falling off a bit down low).
The sealed Ampeg SVT 8x10" cabinet rolls off down low (from around 80 Hz if I remember correctly), but has enough cones to still move air down at 30 Hz.
With a TH with a small high Xmax driver, you can get as much or more clean 30Hz than an SVT in a much smaller cabinet.

Art

 

[papasteack]

Tintinus, please, calm down. I agree with you. It's simplier avoiding crossovers. But it is not the subject. It is not because it's my first thread that i'm a newbie, lol...i've had a life before this forum ^^ . I want go small, and it's both for bass AND guitar. Bass in bi-amping (12w/1w), guitar in normal tube amping 1w. Sharing the tube amp for high when bi-amped.

The thread is about making a 30-180hz tapped horn with a 10" speaker, in 22 liters, for bedroom level. It don't really matter the purposal i want to do of it.
21 liters is very small, so it's a challenge. And the speaker choose is unconventional. This is a "big" speaker for a so small tapped horn. But, in hornresp, it seems ok !
When it will be the time of simulating and building crossover, i'll probably open another thread if i need help. My choose of bi-amping is yet done for this project. I've yet solder some parts. Maybe for another project i'll go fullrange for bass, but it's not for this time.
I stay monoamp/fullrange for guitar of course.

So please stay focus : ciare cw258nd in a 21L th horn fb 28 hz 95db @ 2pi @12w @4 ohm @ 30-180 hz. Good idea ?
weltersys have answered really well, and i really appreciate the motivating arguments comparing to a ampeg 8x10" very well choosen. He have confirmed and made cleaner what i thought about harmonics, db, loudness.......

The only question that remain is about the choose of the driver ... Did i miss a better speaker for this kind of project ? I would have gone eminence because of price if it have been possible, but it just don't work as well in hornresp is so small cab...i've tryed smaller speaker, but it need 2x8 to get the same level, and i would really prefer 1 speaker per cab... more sexy ^^

Some advices about the parameters of the TH ?

 

[Xoc1]

[IMGDEAD]https://lh5.googleusercontent.com/-WynHCr1rfGc/UR_oTMTRpiI/AAAAAAAAAUs/AilF-KzQhPI/s512/hornresp.png[/IMGDEAD]
I've lost my optimised test, but it was not so far from somthing like this...

Papasteack
Looking back at your sim i notice that you havea S4 area of 9 square centimetres
I dont think that this is a realistic area for S4 in a physical horn.

 

[bjorno]

Papasteack
Looking back at your sim i notice that you havea S4 area of 9 square centimetres
I dont think that this is a realistic area for S4 in a physical horn.

Easy to agree with..

b

 

[papasteack]

Thanks !
As far as i understand (and manage to say it in english!), S4 is the area of the horn in front of the speaker near outside mouth. So for a 10", we have to take his middle of the speaker to mesure. How do you suggest to mount the 10" speaker "in S4" ? Speaker front would go to S4 so it instead of rear, it would be easier. As S4 only make 44sq cm, with 3 mm x 14, half the cone should be masked ? I work wood pretty well, it's not a problem. I worry about differential sound pressure on the cone. The 10" cone area, can make S4 bigger (i don't know how to say that in english....) than hippotetical if not considered. It's..."as far as i understand"... Working wood, does the idea should be to make each point of the cone at the same distance of a S4 point, and this S4 point at L34 from a S3 point, and L45 from S5 point ?