What Makes a Loudspeaker Musical?

[Spannko]

The coil in series with the bass driver always has some resistance, enough to make the amplifier connection to the driver worse at low frequencies where they are needed the most . This is where active crossovers has their biggest advantage because of the directly coupled power amplifier.

These are theorical considerations. You get coils with very low resistance. An active crossover is always a parallel crossover so you never get the musical aspects of a series crossover.

True, but even If one uses a thick wire coil with very low resistance of, maybe 0.3 ohms its still more than 0 ohms that you get from a directly coupled amplifier. Using a thin wire coil can make the series resistance as high as 1 ohm .

Have you tried listening for the effect of coil resistance on the loudspeakers musicality? ie same inductance, different wire gauge?

[Rutger]

These are theorical considerations. You get coils with very low resistance. An active crossover is always a parallel crossover so you never get the musical aspects of a series crossover.

True, but even If one uses a thick wire coil with very low resistance of, maybe 0.3 ohms its still more than 0 ohms that you get from a directly coupled amplifier. Using a thin wire coil can make the series resistance as high as 1 ohm .

Have you tried listening for the effect of coil resistance on the loudspeakers musicality? ie same inductance, different wire gauge?

Yes I have - always prefered the lowest resistance coils ( ie 1.6 mm ).

[Spannko]

True, but even If one uses a thick wire coil with very low resistance of, maybe 0.3 ohms its still more than 0 ohms that you get from a directly coupled amplifier. Using a thin wire coil can make the series resistance as high as 1 ohm .

Have you tried listening for the effect of coil resistance on the loudspeakers musicality? ie same inductance, different wire gauge?

Yes I have - always prefered the lowest resistance coils ( ie 1.6 mm ).

Did you try anything even larger? 3mm² for instance?

[Rutger]

Have you tried listening for the effect of coil resistance on the loudspeakers musicality? ie same inductance, different wire gauge?

Yes I have - always prefered the lowest resistance coils ( ie 1.6 mm ).

Did you try anything even larger? 3mm² for instance?

No

[matthias]

https://www.mundorf.com/audio/en/shop/C ... aohm=false

0.02 ohm should not limit your amp :-)

[Spannko]

Yes I have - always prefered the lowest resistance coils ( ie 1.6 mm ).

Did you try anything even larger? 3mm² for instance?

No

OK. Then it’s quite possible that, for your particular application, 3mm² could be less musical than 1.6mm² even though its resistance would be lower. This is something I’ve found with loudspeaker coils and mains transformers: there’s an optimum value somewhere between the minimum and maximum values.

[Spannko]

Imagine also having a bespoke design built only to work in your room, given the room is part of the acoustic system. Very expensive, I imagine!

That’s an interesting idea! It also raises the question, how would the design process differ from any other loudspeaker designed to play tunes harmoniously?

[sunbeamgls]

I don't think it would. It just makes an unknown variable into a known parameter that can be designed around.

[Spannko]

It just makes an unknown variable into a known parameter that can be designed around.

Has this ever been done, do you know?

[sunbeamgls]

I have no knowledge of it. Speakers used to get built in homes in either wooden or brick enclosures in the 50s and 60s, but I doubt there was much science involved, never mind tunedem :)

[sunbeamgls]

……… the cabinet is mechanically intertwined with the driver and alters its electrical behaviour……

This isn’t something I’ve considered previously, but I suppose it must do. Can you expand on this, or provide a link to further information please?

Here are the electrical measurements of a mid-bass driver - from a current retail speaker product.
In the top sweep, the driver is in "free air" - ie suspended on a stand without a cabinet.
The lower sweep, the driver is in its intended ported cabinet.
Blue trace is impedance.
Red trace is phase.

[Tendaberry]

It just makes an unknown variable into a known parameter that can be designed around.

Has this ever been done, do you know?

In high-end car audio applications this very common, sometimes with very good results.

[Spannko]

……… the cabinet is mechanically intertwined with the driver and alters its electrical behaviour……

This isn’t something I’ve considered previously, but I suppose it must do. Can you expand on this, or provide a link to further information please?

Here are the electrical measurements of a mid-bass driver - from a current retail speaker product.
In the top sweep, the driver is in "free air" - ie suspended on a stand without a cabinet.
The lower sweep, the driver is in its intended ported cabinet.
Blue trace is impedance.
Red trace is phase.

Thanks sunbeam, that’s a great example. It’s interesting to see how similar the traces are above about 150 Hz, so the enclosures influence is limited to its effect on the bass drivers resonance. It would be interesting to see the effect of adding the crossover too.

[Rutger]

Imagine also having a bespoke design built only to work in your room, given the room is part of the acoustic system. Very expensive, I imagine!

That’s an interesting idea! It also raises the question, how would the design process differ from any other loudspeaker designed to play tunes harmoniously?

Again, the room is the least important thing for good music !
Why put such amount of energy on something thats brings minimal benefit , compared to a better source or amplifier ( or recording ) ?

If you would invite Nils Lofgren to play guitar in your living room, the most important thing would be a tuned guitar , not damping material on the walls or any room correction programs.

( Theres a lot of confusion about this because Linn has lost its track dipping their toe in room correction programes like space optimisation , probably in an attemt to make more money. )

On a more technical level regarding DIY loudspeaker building, there are one thing that might give real benefits and can be optimised for a special listening room or placement in the room , and thats the ” baffle step compensation ” - dependent on the size of the baffle. It can be between 6 dB to 0 dB at a certain frequency depending on baffle size and the placement of the speaker ( near the wall or free standing )

But this is the only thing , besides correct placement in the room for the speakers using tunemethod, that one has to be concerned about regarding room acoustics when you are building a DIY loudspeaker . Just use your ears during setup.

[sunbeamgls]

Imagine also having a bespoke design built only to work in your room, given the room is part of the acoustic system. Very expensive, I imagine!

That’s an interesting idea! It also raises the question, how would the design process differ from any other loudspeaker designed to play tunes harmoniously?

Again, the room is the least important thing for good music !
Why put such amount of energy on something thats brings minimal benefit , compared to a better source or amplifier ( or recording ) ?

If you would invite Nils Lofgren to play guitar in your living room, the most important thing would be a tuned guitar , not damping material on the walls or any room correction programs.

( Theres a lot of confusion about this because Linn has lost its track dipping their toe in room correction programes like space optimisation , probably in an attemt to make more money. )

You assume that the rest of the chain still needs work, and that spending more money on it gets a better musical result. Neither are good assumptions.

[Rutger]

That’s an interesting idea! It also raises the question, how would the design process differ from any other loudspeaker designed to play tunes harmoniously?

Again, the room is the least important thing for good music !
Why put such amount of energy on something thats brings minimal benefit , compared to a better source or amplifier ( or recording ) ?

If you would invite Nils Lofgren to play guitar in your living room, the most important thing would be a tuned guitar , not damping material on the walls or any room correction programs.

( Theres a lot of confusion about this because Linn has lost its track dipping their toe in room correction programes like space optimisation , probably in an attemt to make more money. )

You assume that the rest of the chain still needs work, and that spending more money on it gets a better musical result. Neither are good assumptions.

Sorry, what I wrote is for the eventual reader (obviously not you or spannko) who has a very bad source and tries to get a perfect sound optimising the loudspeakers and room.

[Spannko]

Another factor in what possibly makes a loudspeaker more musical is a lower enclosure mass. This flies in the face of conventional audiophile wisdom which suggests that the best enclosures are heavy and rigidly braced. However, to date, everything I’ve done to eliminate enclosure resonances, which involves a substantial increase in mass, has had a detrimental impact on the loudspeakers musicality. This week I’m building an enclosure of approximately 600 x 250 x 250 which weighs about the same as the original Kans. It’ll be interesting to see how they turn out.

[matthias]

This week I’m building an enclosure of approximately 600 x 250 x 250 which weighs about the same as the original Kans.

Maybe there is also an inverse relation between dimensions and musicality?

[Spannko]

This week I’m building an enclosure of approximately 600 x 250 x 250 which weighs about the same as the original Kans.

Maybe there is also an inverse relation between dimensions and musicality?

Possibly. I’ve a feeling that each additional kg, regardless of its role or purpose, reduces musicality due to the time it takes for vibrations to decay, thus smearing transients. However, increasing the size of the enclosure, without increasing its mass, leads to a less structurally stable enclosure, possibly also leading to smeared transients. So from a transient response perspective a small, lightweight enclosure may be best. But. As we know, small enclosures don’t usually produce enough bass for a balanced sound on most types of music. I’m hoping that a larger, but no more massive enclosure, positioned close to a wall will produce a speaker with more bass without losing the life in the music.

[Rutger]

This week I’m building an enclosure of approximately 600 x 250 x 250 which weighs about the same as the original Kans.

Maybe there is also an inverse relation between dimensions and musicality?

Possibly. I’ve a feeling that each additional kg, regardless of its role or purpose, reduces musicality due to the time it takes for vibrations to decay, thus smearing transients. However, increasing the size of the enclosure, without increasing its mass, leads to a less structurally stable enclosure, possibly also leading to smeared transients. So from a transient response perspective a small, lightweight enclosure may be best. But. As we know, small enclosures don’t usually produce enough bass for a balanced sound on most types of music. I’m hoping that a larger, but no more massive enclosure, positioned close to a wall will produce a speaker with more bass without losing the life in the music.

You could try to build a stiff thin wall loudspeaker cabinett ( low weight ) but use different thickness on every opposite wall in the speaker to avoid tunefork effects . You could use 12 mm and 16 mm mdf for this. You will probably be surprised by the result.

My experience is the same as yours regarding making heavy loudspeaker cabinets - they sound less tuneful than lighter and stiffer cabinets.

If using raw mdf, one must paint the inside of the cabinet with 50% water and 50% wooden glue or use ordinary paint - mdf leak air and will sound worse If not sealed with paint or glue, especially if its a closed box.

[sunbeamgls]

On the subject of lower mass cabinets, I've heard quite a few open baffle designs (with conventional drivers, not referring here to electrostatics) - essentially as low mass as practically possible. I haven't found any of them to be musical - although most were DIY designs, but that's not an automatic reason for a bad result as I've heard some good DIY speakers too.

[sunbeamgls]

My experience is the same as yours regarding making heavy loudspeaker cabinets - they sound less tuneful than lighter and stiffer cabinets.

That's 2 different parameter changes there - lighter and stiffer. A high mass cabinet can be stiff, and is highly likely to be so. Using the same materials, the lighter cabinet will be less stiff. However, it could potentially be stiffer than the high mass cabinet if the material is changed. But light and stiff materials tend to have very high frequency resonance, so likely to be in the vocal range which will bring significant problems in terms of emotional connection to the music. They can, of course, be damped to an extent, but that usually adds mass! Its a very circular discussion :)

[sunbeamgls]

But this is the only thing , besides correct placement in the room for the speakers using tunemethod, that one has to be concerned about regarding room acoustics when you are building a DIY loudspeaker . Just use your ears during setup.

This is possibly worth exploring further.
Essentially you seem to be saying that tunedemming a speaker's position in the room is important (the movement of the speaker within the room being necessary due to the effects of the room affecting the tune), but that the effects of the room are not important. Can both be true?
Can you expand further on that please?

[Spannko]

On the subject of lower mass cabinets, I've heard quite a few open baffle designs (with conventional drivers, not referring here to electrostatics) - essentially as low mass as practically possible. I haven't found any of them to be musical - although most were DIY designs, but that's not an automatic reason for a bad result as I've heard some good DIY speakers too.

This is my experience too. However, an open baffle design is something I’d like to explore further, particularly since I found out only a couple of days ago that the bass rolls of at 6dB/oct compared to 12dB/oct for a closed box and 18dB/oct for a periodic ported speaker. This gives the open baffle speaker a lower group delay than the other designs. All other things being equal, an open baffle design should work well and I’ve heard drive units just on the workbench sound better than I expected. My guess for our poor experience of open baffle speakers is that they haven’t been designed with a focus on tune playing.

[Spannko]

Maybe there is also an inverse relation between dimensions and musicality?

Possibly. I’ve a feeling that each additional kg, regardless of its role or purpose, reduces musicality due to the time it takes for vibrations to decay, thus smearing transients. However, increasing the size of the enclosure, without increasing its mass, leads to a less structurally stable enclosure, possibly also leading to smeared transients. So from a transient response perspective a small, lightweight enclosure may be best. But. As we know, small enclosures don’t usually produce enough bass for a balanced sound on most types of music. I’m hoping that a larger, but no more massive enclosure, positioned close to a wall will produce a speaker with more bass without losing the life in the music.

You could try to build a stiff thin wall loudspeaker cabinett ( low weight ) but use different thickness on every opposite wall in the speaker to avoid tunefork effects . You could use 12 mm and 16 mm mdf for this. You will probably be surprised by the result.

My experience is the same as yours regarding making heavy loudspeaker cabinets - they sound less tuneful than lighter and stiffer cabinets.

If using raw mdf, one must paint the inside of the cabinet with 50% water and 50% wooden glue or use ordinary paint - mdf leak air and will sound worse If not sealed with paint or glue, especially if its a closed box.

I’m actually actively trying to encourage the tuning fork effect (if I understand you correctly). Research has shown that resonances with a high Q and narrow bandwidth are less audible than resonances with a lower Q and a wider bandwidth. I want all the resonances to align harmonically. This breaks all the rules, I know, but who knows, it might actually work!