Hi just to understand better could you name one example of stroke of genius ? personally speaking of speakers i see a stroke of genius in driver design and construction Like the Heil tweeter for instance Or the plasma tweeter Something that breaks with the standards and provide some amazing performance
but are they really essential ? i do not know honestly
one topic that also fascinate me is horn design I feel that they have an enourmous potential but they are also challenging Like a F1 a small mistake can break the result
sure ? i am not saying that you are wrong i do not know the laws broken
absolutely If the emission of a driver is limited by an adequately shaped felt the waves will not reach the edges Therefore no diffraction
another solution could be waveguides or acoustic lenses Another very interesting topic but way beyond my ability to understand
I have spent years listening to small 2 ways speakers The 1st time i listened to a 3 ways with a powerful 12" woofer i understood that i have spent life listening to a radio Nothing comparable to the real thing In an astonishing way
when i see people listening to Rogers or small Kef i feel sad for them The bass is the body of the sound
the parameters are very clear Volume mass and stiffness The higher the better Compromises must be made for practical reasons
if not a thick steel cabinet could be an answer Or cast iron
yes i agree But i would like to see the glass water test carried out on the best subwoofer when they produce a low tone at high level
that test is very simple and very telling If there will be ripples on the free surface then the unit will not be optimal
The goal of a bass unit is to shake the room's walls Not the cabinet
Thank you very much again I have no doubt about this being by far the best solution And many TOTL full range speakers use this arrangement
one of the very first examples were the AR9 I listened to them at a friend home Unfortunately he was driving them with a low power tube amp
but i have to do with just one direct firing woofer Life is a compromise
Sure?
I think there are so many factors involved.
And the majority of them are unknown. IMHO
I think the purpose of a well-designed subwoofer is to reproduce a quality low range.
I perfectly realize what you mean.
I answered this before I even knew the question. 🙂
Just as an example, you are convinced that felt is sufficient to cancel the diffraction even after the reply of @planet10 who has a huge experience and knowledge in the field of speakers (while I speak only on a hypothetical level only because I like to measure myself with what in my humble long "career" as a passionate amateur I believe I've realized, not only in relation to Audio).
And even after seeing the thread I pointed you to before, and that's fine, just because each of us has our own obsessions (I mean that in the best sense, of course).
Incidentally I own a pair of floorstanding speakers designed and built by a brilliant speaker designer (who had discovered and knew how to make even relatively inexpensive drivers sound extraordinarily good) called Peter Snell (R.I.P.) that have a thick sheet of felt on the sides and around the tweeter and midrange and they sound amazingly good.
Your obsession seems to be the low range and building the perfect subwoofer cabinet, which is great!
Bat that's not all, If you know what I mean. 😉
You also want to separate the cabinet (if any) of tweeter and midrange from that of the woofer, which is very good, but after all why be obsessed with it?
What I mean is that I like to see you obsessed with a parameter, but in my opinion it should not be lost sight of the fact that it is only one parameter, while there are dozens of others that are automatically possibly neglected.
So, the gphenio coup in my opinion is to be able to balance the various important characteristics that are known today.
Unless proven otherwise, the majority of successful designers behave this way.
And there is definitely a good reason for that. IMHO
Your preference is the most important thing in the world, in my opinion, because the fun that comes from it is yours and yours alone.
And there is definitely a good reason for that.
I strongly believe that your preferences are the most important things in the world for you just because the fun that comes from them is yours and yours again. 🙂
None, it's a legend, but I needed it to reinforce the concept. 😍
Hi ! i guess that subwoofers manufacturers know what they are doing It should not be rocket science
sais in another way it is always the same goal To detach the sound from the box This is what i mean for sound coming from the space around the speakers
The quality of the bass is very easy to assess using the right tracks I have never had a good bass from my small size speakers
Some instruments like piano and pipe organ sound unrealistic Not right
🙂👍
if i understand well diffraction issues should result in some up and down in the frequency response
i have just watched a video about a speaker with these problems The use of felts has reduced the irregularities a lot More than enough for me
If the FR is reasonably flat is fine to me
this is what i would call a great understanding of things We can call him genius or just a very competent scientist
in today world the virus of the marketing pervades the sector I see ridiculous things at ridiculous prices
weird solutions not always backed by scientific concepts or measurements
this sounds to me like a confirmation of the usefulness of felts
i have some problems with wide speakers i dont like them because my room is small Room is a limiting factor
of course thats not all I have other obsessions but not audio related
i prefer this solution because it allows to me to experiment with different solution for the mid-high section
small line arrays coaxial full range etc. there are many possible solutions for the head lets say
cover more band with the bass like up to 500Hz will make the head design and construction less challenging
I have another big issue I I'll need a carpenter to make me the two bass boxes I do not have tools and skills
for the head I can make do by modifying little boxes recovered here and there I am optimistic for this
I see I think that a key factor for a successful design is a deep understanding of drivers behaviours and performance
i am already lost at the parts selection stage I see the catalogues I see woofers of the same sizes ranging from 20 to 1000 USD
i cannot spot the component with the best performance to cost ratio This is what i mean for deep understanding
but in general given a driver i can run some basic measurements but i have no clue about how to assess its sound quality I have to rely on other people evaluations
if i make a ugly pie i much prefer to buy one good I do not get the least satisfaction from doing something by myself if it is not working great
actually it is the contrary i am afraid of failing a lot That would depress me deeply Another blow to an already low self-esteem
Thank you very much again for your very kind and valuable advice
Have a nice day
Please read the above just as "But that's not all, If you know what I mean", sorry.
And
As "the stroke of genius", thanks.
That's true, but it could become even more difficult than that. 🙄
In my humble opinion the real difficulty is to make it sound good too.
And at reasonable prices.
And with reasonable construction difficulties.
It's all very relative then.
That's why I said the only thing that matters is that you like your own obsession.
Because it's the only thing that gives meaning to all your efforts.
Try to balance everything, even your beliefs and especially the compromises you will be forced to choose, that's where the genius lies.
A nice day from me too. 🙂
Hi ! thank you very much indeed Very interesting solution I will try them for sure
This will be the subject of next phases of the plan
I am still studying the bass box topic It will take me some time
The construction seems much more challenging than the design
I would never use fiberboard I would use good wood braced and damped with sheets of something
Unfortunately it has to be very heavy
this is the key question What really to sound good means It is all in the definitionPlease read the above just as "But that's not all, If you know what I mean", sorry.
And
As "the stroke of genius", thanks.
That's true, but it could become even more difficult than that. 🙄
In my humble opinion the real difficulty is to make it sound good too.
Good is not like weight depth height distortion fs impedance BL Xmax and so on
It is a quality difficult to define like the taste of a steak
and for its nature is subjective
And of course a very good driver in a bad cabinet or xover
cannot provide the top performance it is capable of
while reasonable price with a competent screeing is achievable again the real issue is the cabinet
i do not know if it is just marketing but look at how big heavy and so expensive are the bass boxes on high end TOTL speakers
because there are no limits
the stiffer the heavier the bigger the cabinet the better
if you make it standalone moving and placing it in the room will be easier
i love things like these
this thing could cover all the lower band of the audio spectrum up to lets say 500Hz like no other conventional speaker can
because it is designed and built for the purpose To use it only as a sub i.e. up to 100Hz is a waste
when you have found a very good solution for the bass the remaining part have many options They could be even horns or what you like best
🙂👍
Hi very challenging application indeed I see solutions out this world Like cast iron plinths weighing even 200kg
this is exactly what i think it is needed The main displacement of a bass cabinet should be in the horizontal direction forward and backward
with the only resistance to the displacement provided by the cabinet mass That should be as huge as possible
they seem really an excellent solution indeed and also very cheap
actually i am willing to accept a so so look in order to get a good performance
i usually prefer to listen with lights off and only the tv screen on Like in a movie theater i mean The lights can be disturbing
Thanks a lot again for the great advice
Hi thank you very much for your valuable advice I am not sharp enough to understand all the principles and equations behind the turntables technology
I was shocked by hearing that in order to null the displacement of a bass cabinet due the cone movement the mass of the cabinet should be 5000 times the mass of the moving cone Considering a value of 50g for the cone that means 250kg If true i would consider this an ideal value
The reality could only approach that value But the importance conclusion is that mass plays a fundamental role in the mechanical behaviour of a bass cabinet and will have a remarkable impact on the unit performance
The movement of the cabinet could be made evident with simple test like using a glass on top half filled with water and looking for any ripple on the free surface
If the water comes out is not a good sign and in some bad cases could be
I think that i have most of the questions about woofer cabinets answered and i am worried by the outcome
i think that some 30kg could be a very minimum for the cabinet mass
It's commonly used in racing on dashes. https://en.wikipedia.org/wiki/Flocking_(texture) Looks kinda like velvet, you can get it with different materials, length, stiffness's and density's. The felt made me wonder if it has been tried (I imagine it must have) and what the effect was?
Thank you for the reply I am not an expert but i guess that also moquettes of different hair length can be tested
the choice is quite immense
i saw a very interesting video on the Wilson Audio Watt edition 8
They have discovered that the irregularities in the FR above 1kHz can be linked to diffractions caused by the cabinet edges
https://www.stereophile.com/content...s-wattpuppy-system-8-loudspeaker-measurements
some felts strategically placed have tamed the effect a lot
some testing is needed with different felt sizes and positioning
the choice is quite immense
i saw a very interesting video on the Wilson Audio Watt edition 8
They have discovered that the irregularities in the FR above 1kHz can be linked to diffractions caused by the cabinet edges
https://www.stereophile.com/content...s-wattpuppy-system-8-loudspeaker-measurements
some felts strategically placed have tamed the effect a lot
some testing is needed with different felt sizes and positioning
But only at high frequencies. It does nothing for the low end of the spectrum. The nature of the baffle step diffration depends heavily on the box shape.
dave
Hi i trust your advice at this point i would stay away from the light ones At least
i am also suspicious about the woofer quality Difficult to say if they are good or not without measurements
from the plots above it seems that a spherical cabinet could be the best ?
still that kind of shape is very rare
i see many speaker with quite sharp edges or even recessed drivers especially old ones
do you mean that boxiness could be related to diffractions from the speaker edges ? like emissions out of phase with the main emission of the driver ? it is getting complicated then
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If a sub is push-push, light is fine. The cabinet of the best sub i have built could be lifted with a couple fingers in the driver cutout (more like a 2 man lift when drivers installed).
dave
In a subwoofer producing low frequencies, the box size would have to be huge to reach into the range where the box shape affects the 2∏ to 4∏ radiation transition.
dave
yes this is very clear to me But i feel umcomfortable with emissions that are not frontal I understand that the push push is the best concept for vibrations control Then i would need 4 woofers
the fact is that i see so many decent speakers with just one woofer I understand that they could be compromised
But after all the B&W 801 were good enough for the Decca and Deutsche Gramophone studios and they have just one big woofer
i have never listened to them but are quite similar to what i have in mind at a smaller scale of course
I do not think that the complicated head construction is really neeeded
https://forum.audiogon.com/discussions/the-hub-bowers-wilkins-801-good-bad-or-ugly
not a very new idea i see The 801s i think were the answer to the Kef 105 appeared 2 or 3 years before Similar concept
i listened to the 105 1st series and liked them a lot The bass from old british speakers seems a little slow and rounded A litttle muddy I do not like
Both heads are really nice but too complex for me A small 2 ways on top and it is done
In conclusion even i agree with the superior performance of the 2 woofers back to back solution i prefer the single woofer solution