3 way speaker Q's

[yepimonfire]

now for another question since i am getting confused, what do you mean "weaker bass" doesent response have to do with the +-3dB rating? would a speaker that has a -3dB response of 45hz have the same bass as another one that has a -3dB response at 45hz? if not explain. i am not an idiot, i am still learning, instead of posting immature comments why don't you just correct me? i am here to learn just like everyone else. so far everything i have said i have learned on this forum.

 

[adwilk]

now for another question since i am getting confused, what do you mean "weaker bass" doesent response have to do with the +-3dB rating? would a speaker that has a -3dB response of 45hz have the same bass as another one that has a -3dB response at 45hz? if not explain. i am not an idiot, i am still learning, instead of posting immature comments why don't you just correct me? i am here to learn just like everyone else. so far everything i have said i have learned on this forum.

Simply put, one speaker will still have a greater maximum output.

 

[yepimonfire]

oh i already know that. which is why i said i worded it wrongly

 

[adwilk]

Well lets just say that speaker A is -3db @ 35 hz with maximum output of 90db
for the sake of discussion

Lets say speaker B is also -3db @ 45hz with maximum output of 110db, again for sake of argument.

Which speaker has stronger 45hz output at 105db? Lets assume that their sensitivities, impedance curves, and the electronics used are all the same...

Like was said, your mixing up extension and spl in those frequency ranges. You could have a speaker whos extension was flat down to 10, but if the maximum SPL was 50db, then a speaker whos extension was down 3db at 60hz that had maximum spl of 150db (exaggerated numbers for point) the latter speaker will have much "stronger" bass output.

You can almost forget how "strong" the bass is gonna be just by looking at its overall frequency capabilities...

 

[yepimonfire]

if they are both played at the same volume, lets say 70dB since this is a common listening volume, atleast for me. would the bass seem stronger in the one with more output?

 

[yepimonfire]

also for the sake of education, won't a speaker that rolls of more smoothly seem to have better bass then one that rolls of sharply? for instance the monitor 40s i have have significantly less noticeable bass output then my sony floorstanders but the sonys will actually play sound all the way down to 20hz at an audible volume, the polks roll of so steeply at 47hz, that if you play a 30hz tone through them, there is absolutely no audible sound generated. the difference in frequency response between the two is only 3hz, and im sure that sony's specs are exaggerated.

 

[adwilk]

You bring up some interesting points concerning slopes and whatnot and while its all science, the way the bass is actually produced vs heard can be deceiving as well.

At the end of the day, your ears are the judge- but things like room gain, placement, reflections, blah blah blah also dictate which speaker might have a seemingly stronger bass response in a real life application. Don't get too caught up in trying to determine what speaker might sound like based on its specs. The example pointed out in this thread was only one example- only to topple an "absolute" point that you had made.

 

[Loren42]

no i worded it wrongly, i know that they wont be able to output the same level as a large pro speaker.

You are right there, but you risk more distortion out of the smaller driver because it must have a much larger linear region for the voice coil to operate within.

However, you also need to realize the issue of directivity of a driver and how it matches it's neighbor to produce a smooth on ad off-axis response.

Have a look at this link for more information.

This provides a better explanation of why driver size is important. It doesn't mean that a 6" driver is unsuitable for bass reproduction, but a larger woofer of equivalent quality is more desirable.

The downside is a larger driver requires more floor space and that is something few of us can stand in our rooms. So a compromise is typical.

 

[yepimonfire]

You bring up some interesting points concerning slopes and whatnot and while its all science, the way the bass is actually produced vs heard can be deceiving as well.

At the end of the day, your ears are the judge- but things like room gain, placement, reflections, blah blah blah also dictate which speaker might have a seemingly stronger bass response in a real life application. Don't get too caught up in trying to determine what speaker might sound like based on its specs. The example pointed out in this thread was only one example- only to topple an "absolute" point that you had made.

i have also noticed how ported enclosures may gain you an extra 10-30hz in response at -3dB, but below that tuning frequency the actual slope drops like a rock. for instance, i had a sealed sub with a response down to 35hz and i now have due to the sealed one dieing on me a ported sub with a response down to 35hz, based on test tones, the sealed sub would actually produce audible sound down to a good 15hz without distortion, sure you had to crank the volume up about 6 more dB then at 35hz but it was there none the less, the ported one will not produce any sound even if you crank the knob to max (minus port chuffing) below 30hz. if you plug the number of the same driver into a ported calculator and a sealed calculator you will notice how the sealed response curve is a slow gradual roll off with sound all the way down to 10hz minus 9 dB, the ported one drops off steeply (about 10dB every 10hz) below the lowest frequency it is capable of producing. sure you can also get the slower slope on a ported box if you mess with the QTC, but that kind of defeats the reason for using a port imo.

 

[adwilk]

i have also noticed how ported enclosures may gain you an extra 10-30hz in response at -3dB, but below that tuning frequency the actual slope drops like a rock. for instance, i had a sealed sub with a response down to 35hz and i now have due to the sealed one dieing on me a ported sub with a response down to 35hz, based on test tones, the sealed sub would actually produce audible sound down to a good 15hz without distortion, sure you had to crank the volume up about 6 more dB then at 35hz but it was there none the less, the ported one will not produce any sound even if you crank the knob to max (minus port chuffing) below 30hz. if you plug the number of the same driver into a ported calculator and a sealed calculator you will notice how the sealed response curve is a slow gradual roll off with sound all the way down to 10hz minus 9 dB, the ported one drops off steeply (about 10dB every 10hz) below the lowest frequency it is capable of producing. sure you can also get the slower slope on a ported box if you mess with the QTC, but that kind of defeats the reason for using a port imo.

Gotta be really honest, I no longer know what you're talking about...

 

[yepimonfire]

basically i've noticed ported enclosures roll off steeper then sealed.

 

[Loren42]

basically i've noticed ported enclosures roll off steeper then sealed.

Yes, the rolloff is about 12 dB/octave. However, they remain flat (if properly designed) much lower than a sealed cabinet and this is one of the reasons they are popular.

Which design you use is usually determined by the driver's Qts.

 

[yepimonfire]

Yes, the rolloff is about 12 dB/octave. However, they remain flat (if properly designed) much lower than a sealed cabinet and this is one of the reasons they are popular.

Which design you use is usually determined by the driver's Qts.

mind explaining why and what the QTS has to do with it? i've never heard that before, i do plan on building speakers in the future so all the knowledge i can accumulate beforehand would be great.

 

[Loren42]

mind explaining why and what the QTS has to do with it? i've never heard that before, i do plan on building speakers in the future so all the knowledge i can accumulate beforehand would be great.

Buy a copy of Vance Dickenson's Loudspeaker Design Cookbook. That is the best way to get started.

That book has a mountain of useful information.

 

[AJinFLA]

Yes, the rolloff is about 12 dB/octave.

To clarify, that's for the the sealed. 24 db/oct for the reflex eventually (some may have a shallower initial roll off, such as EBS, TL, etc.).

However, they remain flat (if properly designed) much lower than a sealed cabinet

In free space. In a real room, anything but.

and this is one of the reasons they are popular.

A tragic situation (due in no small part to little/no demand for fidelity to acoustic sounds, but rather booming, droning explosions/"speaker sound").
Classic market supply and demand.

cheers,

AJ

 

[yepimonfire]

To clarify, that's for the the sealed. 24 db/oct for the reflex eventually (some may have a shallower initial roll off, such as EBS, TL, etc.).


In free space. In a real room, anything but.


A tragic situation (due in no small part to little/no demand for fidelity to acoustic sounds, but rather booming, droning explosions/"speaker sound").
Classic market supply and demand.

cheers,

AJ

yea this is kind of what i was explaining earlier, i would rather gain an audible octave of notes rather then just have extra good bass down to the -3dB point and then have none at all below it.

 

[yepimonfire]

FYI
Alex2507, i'm not the one who did anything to you about a flame war, you need to stop acting immature, this is the second thread you have trashed my rep on when i was not even doing anything to you.

 

[Loren42]

To clarify, that's for the the sealed. 24 db/oct for the reflex eventually (some may have a shallower initial roll off, such as EBS, TL, etc.).


In free space. In a real room, anything but.


A tragic situation (due in no small part to little/no demand for fidelity to acoustic sounds, but rather booming, droning explosions/"speaker sound").
Classic market supply and demand.

cheers,

AJ

Thanks for the correction on the rolloff. It is typically about 18 to 20 dB for flat alignments.

Yes and no, that is actually in half-space, but a sealed cabinet does the same thing, so what is your point?

Lastly, if your opinion of a vented enclosure is that it is not HiFi, then that is because you never heard one that was correctly designed.

 

[AJinFLA]

Thanks for the correction on the rolloff. It is typically about 18 to 20 dB for flat alignments.

You're welcome. What is a "flat alignment"?

Yes and no, that is actually in half-space

No. The standard FR measurements (and sims) are free space, no planes. (Or very nearfield)

but a sealed cabinet does the same thing, so what is your point?

The 12db/oct vs 24/db/oct (monopoles) placed into a room (with gain) will exhibit very different acoustic response. Measurably and audibly. The vented typically being overboosted....hence their popularity.

Lastly, if your opinion of a vented enclosure is that it is not HiFi, then that is because you never heard one that was correctly designed.

But of course .
Never heard that response before .
So after 30+ yrs, which vented system should I have listened to, specifically? After reading (and hopefully, understanding) this article and this thread, can you explain how the vented system(s?) that I've missed all these years, physically (not your subjective opinion) avoid the problems measured and audibly identified?
TIA Loren.

cheers,

AJ

 

[Loren42]

You're welcome. What is a "flat alignment"?

For vented:

Super Forth-Order Boom Box
Forth-Order Sub-Chebyshev
Quasi Third-Order

At least these are the old names.

Box loss will impact alignment as well.

No. The standard FR measurements (and sims) are free space, no planes. (Or very nearfield)

I know infinite baffle (2∏), full-space (4∏), half-space (ground plane), quarter-space, and eighth-space.

What is free-space? I am guessing it isn't a no-rent loft with speakers.

The 12db/oct vs 24/db/oct (monopoles) placed into a room (with gain) will exhibit very different acoustic response. Measurably and audibly. The vented typically being overboosted....hence their popularity.

That argument is just silly. You can grab any speaker you want and they all sound different. I think what your saying is a loudspeaker with a diminished bass response might better fit some room, but every room is different anyway, so were are back to what will you use for a reference? I assume it is free-space.

But of course .
Never heard that response before .
So after 30+ yrs, which vented system should I have listened to, specifically? After reading (and hopefully, understanding) this article and this thread, can you explain how the vented system(s?) that I've missed all these years, physically (not your subjective opinion) avoid the problems measured and audibly identified?
TIA Loren.

cheers,

AJ

Is your stance that no vented enclosure can sound good? Is there a consensus on that? I think Vandersteen uses ports. Wilson Audio is another. Are they junk?

The links, thank you, are interesting, but I did not see where they support your argument that a vented enclosure is a poor loudspeaker.

Maybe it would be good to reiterate exactly what your claim is so I am clear.

Thanks.