Back to the topic,
I was just down in my carport and I decided to grab another amp and hook up both the A4 (bass only) and the A7 (full range) at the same time. Each amp was set at one watt. ( music program: 0.1 - 10 watts )
With the high efficiency 15" drivers, I begin to understand why you can get away with a ten watt tube amp in a small location.
No one can tell me that an 6 1/2" or multiples of it, or for that matter 8", even at a 100 watts or more is going to do that kick drum the justice that I was hearing in drivers that are supposed to need lots of watts to "get going"
If the concert is played through these kind of drivers then why not at home too. Good bang for the buck. An EQ can look after some of the shortcomings.
Am I too old and out of touch?
Happy gonad rattling bass,
Cal
I was just down in my carport and I decided to grab another amp and hook up both the A4 (bass only) and the A7 (full range) at the same time. Each amp was set at one watt. ( music program: 0.1 - 10 watts )
With the high efficiency 15" drivers, I begin to understand why you can get away with a ten watt tube amp in a small location.
No one can tell me that an 6 1/2" or multiples of it, or for that matter 8", even at a 100 watts or more is going to do that kick drum the justice that I was hearing in drivers that are supposed to need lots of watts to "get going"
If the concert is played through these kind of drivers then why not at home too. Good bang for the buck. An EQ can look after some of the shortcomings.
Am I too old and out of touch?
Happy gonad rattling bass,
Cal
ROOM SIZES and LOW FREQUENCIES
Carl,
If you’re out side the bass driver has the ability to reproduce the full wavelength.
For a low frequency to be produced properly the wavelength must fit inside the room's dimension. If L = V / f, then you need a minimum length of 17.2m for a 20Hz frequency to be produced. If not you are just creating standing wave and room modes and resonaces. Of course, you can feel the sound pressure at low frequencies and the biger driver willput out more volume and play much louder.
f = V / L, [f = frequency (Hz or cycles/sec), V = velocity of sound (m/sec) and L = wavelength (m)].
Also, while the majority of lager woofer or more efficient than smaller ones they also present a more difficult impedance load on the amp. Therefore, with these speakers you need an amp with a good damping factor that can control the driver.
If you want to get rid of frequency modes in your room and you don't have a big room you will need sound traps.
I like big drivers I just have found that they or not that practical for normal size listen areas. Therefore, I stick with smaller drivers, hey but audio is all about choices.
Carl,
If you’re out side the bass driver has the ability to reproduce the full wavelength.
For a low frequency to be produced properly the wavelength must fit inside the room's dimension. If L = V / f, then you need a minimum length of 17.2m for a 20Hz frequency to be produced. If not you are just creating standing wave and room modes and resonaces. Of course, you can feel the sound pressure at low frequencies and the biger driver willput out more volume and play much louder.
f = V / L, [f = frequency (Hz or cycles/sec), V = velocity of sound (m/sec) and L = wavelength (m)].
Also, while the majority of lager woofer or more efficient than smaller ones they also present a more difficult impedance load on the amp. Therefore, with these speakers you need an amp with a good damping factor that can control the driver.
If you want to get rid of frequency modes in your room and you don't have a big room you will need sound traps.
I like big drivers I just have found that they or not that practical for normal size listen areas. Therefore, I stick with smaller drivers, hey but audio is all about choices.
How about having some small AND big drivers?
Actually, joke aside, these 15" prodrivers as far as bass is concerned tend to sound tight and "punchy" as opposed to "boomy". But my cabinets are tuned "only" to 35Hz or so and the room is about 21' X 15' with 11' ceilings:.
Concerning efficiency: look at where the midrange amps are set in relationship to the woofers. The AUDAX PR17M0 put out 100dB
@1W/1M, hard to match with the JBL at 92dB and the VIFA XT at 91 dB. At low volumes I could probably attach the mids DIRECTLY to the output of the active crossover...
Cheers
Actually, joke aside, these 15" prodrivers as far as bass is concerned tend to sound tight and "punchy" as opposed to "boomy". But my cabinets are tuned "only" to 35Hz or so and the room is about 21' X 15' with 11' ceilings:.
Concerning efficiency: look at where the midrange amps are set in relationship to the woofers. The AUDAX PR17M0 put out 100dB
@1W/1M, hard to match with the JBL at 92dB and the VIFA XT at 91 dB. At low volumes I could probably attach the mids DIRECTLY to the output of the active crossover...
Cheers
Attachments
Re: ROOM SIZES and LOW FREQUENCIES
This is absolutely factually incorrect. Especially in the case of most pro-audio drivers, the converse is actually the case!
Peace
jewilson said:[B
Also, while the majority of lager woofer or more efficient than smaller ones they also present a more difficult impedance load on the amp. Therefore, with these speakers you need an amp with a good damping factor that can control the driver.
This is absolutely factually incorrect. Especially in the case of most pro-audio drivers, the converse is actually the case!
Peace
Re: ROOM SIZES and LOW FREQUENCIES
Konnichiwa,
In order to not have my post edited/deleted again I will avoid the factual evaluation of the exact degree of incaccuracy of this statement. Let's keep it absolutely simple.
To hear a given tone what is needed is a pressure change. A pressure change will still occour in the room and thus in the ear channel if the wave cannot develop, because the room dimensions are too small. That is a simple fact, demonstrable, observable and extensively proven. The simplest solution is a closed back headphone or indeed a speaker enclosure itself.
I would really appreciate if you would refrain from re-posting the above thesis as fact, because it is completely and utterly irrelevant (I would prefer a much stronger anglosaxon word here) in the context of reproducing low frequencies in a room.
Actually, I must correct your statement, as leaves much to be desired in accuracy or reality. The simple FACT is that once the HALVE wavelength becomes longer than the longest room dimension room modes cease to exist and the room becomes a (leaky) pressure chamber, where the SPL rises with a 2nd order function, if the room is sufficiently airtight and the walls sufficiently rigid.
Room modes or by other words standing waves or resonances CAN ONLY EXIST if at least halve a wavelength corresponds to a room dimension. This means your 17.2m Room will be subject to room modes/room resonances/standing waves at all from 10Hz upwards and below 10Hz will show for the same acoustic input a rise of the sound pressure level by around 9 - 12db per octave, depending upon how sealed the room is.
Taking a more reasonable room with 4.5m X 5.5m X 2.4m we find that room modes can occur down to 31Hz, below this the room will NOT behave in way resonant and observed sound pressure will rise at around 12db/Octave, so if we place a sealed enclosure with a f3 of 30Hz in this room as subwoofer, the SPL is being retained as a flat response pretty much down to DC or the Excursion limts of the Driver or the response limit of the Amplifiers, whichever occurs first.
Above around 30Hz we observe room modes at:
31.4Hz
38.3Hz
62.8Hz
71.9Hz
76.6Hz
94.2Hz
114.9Hz
125.6Hz
143.8Hz
153.2Hz
157Hz
188.4Hz
191.5Hz
215.7Hz
219.8Hz
229.8Hz
251.2Hz
268.1Hz
282.6Hz
287.6Hz
and so on.
I would assert that above around 300Hz the density of the modes becomes large enough to allow the room to be counted to have transited into the reverbrant (Sabian IIRC) range.
So, the fact is that reality behave in exactly the opposite way to your assertation. Please refain in future from repeating again this ridiculusly distorted view of how acoustics really work.
Hmmm. I wonder what particular "fact" this assertation is based? It can be easily illustrated; by comparing the phase angles and impedances; that most speakers based around large size woofers provide a higher impedance load with less severe combinations of phase-angle and low impedance than is present when using small drivers overtaxed to extend their LF cutof low. Moreover, the Amplifier will be asked, for a given SPL at a given frequency to produce much less current (and voltage) into the load and will have to handle much lower levels of back EMF.
In my considered opinion the above clearly constitutes the larger, higher efficiency driver as a less difficult to drive load than the small driver.
Again, reality behaves in clear and obvious contradiction of your assertation and it takes only the barest smidgen of logic to work that out as well.
That again is an assertation that sadly lacks substantially any correlation with reality. The reasons are set out above, I shall save myself repeating them. However, please rfrain from asserting again such a completely fictional view of reality as fact. It upsets my sense of reality.
BTW, may I return your kind favour of recommending to me some reading material earlier in the thread. I believe the kind of reading beneficial to you might start with Aristotle's Tratsies on the subject of logic, it may help avoiding to get as many things back to front.
Sayonara
Please do not adjust your mind
It is reality that is faulty
and requires percussive maintainance.
Konnichiwa,
jewilson said:
In order to not have my post edited/deleted again I will avoid the factual evaluation of the exact degree of incaccuracy of this statement. Let's keep it absolutely simple.
To hear a given tone what is needed is a pressure change. A pressure change will still occour in the room and thus in the ear channel if the wave cannot develop, because the room dimensions are too small. That is a simple fact, demonstrable, observable and extensively proven. The simplest solution is a closed back headphone or indeed a speaker enclosure itself.
I would really appreciate if you would refrain from re-posting the above thesis as fact, because it is completely and utterly irrelevant (I would prefer a much stronger anglosaxon word here) in the context of reproducing low frequencies in a room.
jewilson said:
Actually, I must correct your statement, as leaves much to be desired in accuracy or reality. The simple FACT is that once the HALVE wavelength becomes longer than the longest room dimension room modes cease to exist and the room becomes a (leaky) pressure chamber, where the SPL rises with a 2nd order function, if the room is sufficiently airtight and the walls sufficiently rigid.
Room modes or by other words standing waves or resonances CAN ONLY EXIST if at least halve a wavelength corresponds to a room dimension. This means your 17.2m Room will be subject to room modes/room resonances/standing waves at all from 10Hz upwards and below 10Hz will show for the same acoustic input a rise of the sound pressure level by around 9 - 12db per octave, depending upon how sealed the room is.
Taking a more reasonable room with 4.5m X 5.5m X 2.4m we find that room modes can occur down to 31Hz, below this the room will NOT behave in way resonant and observed sound pressure will rise at around 12db/Octave, so if we place a sealed enclosure with a f3 of 30Hz in this room as subwoofer, the SPL is being retained as a flat response pretty much down to DC or the Excursion limts of the Driver or the response limit of the Amplifiers, whichever occurs first.
Above around 30Hz we observe room modes at:
31.4Hz
38.3Hz
62.8Hz
71.9Hz
76.6Hz
94.2Hz
114.9Hz
125.6Hz
143.8Hz
153.2Hz
157Hz
188.4Hz
191.5Hz
215.7Hz
219.8Hz
229.8Hz
251.2Hz
268.1Hz
282.6Hz
287.6Hz
and so on.
I would assert that above around 300Hz the density of the modes becomes large enough to allow the room to be counted to have transited into the reverbrant (Sabian IIRC) range.
So, the fact is that reality behave in exactly the opposite way to your assertation. Please refain in future from repeating again this ridiculusly distorted view of how acoustics really work.
jewilson said:
Hmmm. I wonder what particular "fact" this assertation is based? It can be easily illustrated; by comparing the phase angles and impedances; that most speakers based around large size woofers provide a higher impedance load with less severe combinations of phase-angle and low impedance than is present when using small drivers overtaxed to extend their LF cutof low. Moreover, the Amplifier will be asked, for a given SPL at a given frequency to produce much less current (and voltage) into the load and will have to handle much lower levels of back EMF.
In my considered opinion the above clearly constitutes the larger, higher efficiency driver as a less difficult to drive load than the small driver.
Again, reality behaves in clear and obvious contradiction of your assertation and it takes only the barest smidgen of logic to work that out as well.
jewilson said:
That again is an assertation that sadly lacks substantially any correlation with reality. The reasons are set out above, I shall save myself repeating them. However, please rfrain from asserting again such a completely fictional view of reality as fact. It upsets my sense of reality.
BTW, may I return your kind favour of recommending to me some reading material earlier in the thread. I believe the kind of reading beneficial to you might start with Aristotle's Tratsies on the subject of logic, it may help avoiding to get as many things back to front.
Sayonara
Please do not adjust your mind
It is reality that is faulty
and requires percussive maintainance.
jewilson said:
If I may comment,
A bass pipe uses resonance to amplify an initially small undifferentiated sound stimuli, (i.e. white noise over a reed). This is basically the same principle as a laser.
Bass from a speaker, however, is differentiated and amplified, and thus needs, (and ideally should have), no further frequency/amplitude dependant effects
Konnichiwa,
I do not have to. An organ pipe is a resonance amplifier (see other replies). It is the exact reverse of what weould like the listening room to be. If you want to make sure that your maximally AMPLIFIES a given frequency, you must of course choose the room dimensions accordingly.
I prefer my room actually to be used for reproducing music and not for amplifying single tones, but that's just me of course, strictly, and strictly my personal preference.
I would again recommend that you consider reading up on logic and acoustics. It seems very much desirable.
Sayonara
jewilson said:
I do not have to. An organ pipe is a resonance amplifier (see other replies). It is the exact reverse of what weould like the listening room to be. If you want to make sure that your maximally AMPLIFIES a given frequency, you must of course choose the room dimensions accordingly.
I prefer my room actually to be used for reproducing music and not for amplifying single tones, but that's just me of course, strictly, and strictly my personal preference.
I would again recommend that you consider reading up on logic and acoustics. It seems very much desirable.
Sayonara
There seems to be two common micsonceptions in this thread. One is that lighter mass (cone) = "fast bass" and the other is the lowest frequency supported by a room.
The lowest frequency vs room size has pretty much been beaten into the ground. One way to think of it is not so much a wavelength issue, but as a time issue, which we know is one and the same. I think of it as the driver is pulsing pressure waves into the room at a given time interval. Which for a 20 hz signal is 1/20 seconds.
The fast bass issue is probably the most common myth in all of audio. The planar ribbon guys are constantly searching for that perfect sub that can "keep up" with thier ultra light speakers.
The fact is, mass has NOTHING to do with it. BL/mass has nothing to do with it either. Mass effects only the efficiency/sensitivity of the driver. Add enough mass to a driver that is rated for 90dB/1w/1m and you will end up with an 87dB/1w/1m driver. The driver inductance is what controls the transient responce of a driver. The inductance controls the current and the current is what provides the force, as in BLi. So look for a driver with a low Le.
There are more detailed explanations on the web. www.adireaudio.com is a good place to start.
If you want that nice, tight , "pound in the chest" bass, just pump up the 50 - 80 hHz region. Don't take my word for it, ask anybody who has run a sound board.
Russ
The lowest frequency vs room size has pretty much been beaten into the ground. One way to think of it is not so much a wavelength issue, but as a time issue, which we know is one and the same. I think of it as the driver is pulsing pressure waves into the room at a given time interval. Which for a 20 hz signal is 1/20 seconds.
The fast bass issue is probably the most common myth in all of audio. The planar ribbon guys are constantly searching for that perfect sub that can "keep up" with thier ultra light speakers.
The fact is, mass has NOTHING to do with it. BL/mass has nothing to do with it either. Mass effects only the efficiency/sensitivity of the driver. Add enough mass to a driver that is rated for 90dB/1w/1m and you will end up with an 87dB/1w/1m driver. The driver inductance is what controls the transient responce of a driver. The inductance controls the current and the current is what provides the force, as in BLi. So look for a driver with a low Le.
There are more detailed explanations on the web. www.adireaudio.com is a good place to start.
If you want that nice, tight , "pound in the chest" bass, just pump up the 50 - 80 hHz region. Don't take my word for it, ask anybody who has run a sound board.
Russ
Honestly! Has this thread become a haven for pro-audio loudness-at-any-cost fanatics?
Wavelength issue: thankfully beaten to death. I'll just twist the knife if I may, by asking: what the heck is a wavelength anyway? Isn't it just an abstract definition of "frequency" by converting it to distance after some rough assumptions about the speed of sound? At 20Hz the measurement accuracy between successive peaks in air-pressure would probably be around +-5 metres. It's really the average time difference between pressure peaks that's important.
Back to 15" drivers:
Box size: huge, too big for anything except LOW BASS. Just like rooms have room-modes, boxes have "box-modes". With a box that's 100L or so, it'll be a struggle to achieve high quality sound even with extreme efforts with damping techniques and materials. If room-modes are considered bad, then what about box-modes that start above 150Hz or so? Even if the walls of the box are perfect and let out no sound, the cone itself will be the source of resonances escaping from inside the box. Personally, I don't know of any material that can absorb frequencies from 150Hz to 400Hz or so and fit inside a 100L box. Even if a 4th-order filter is used at 80Hz, the speaker will still produce some sound at 150Hz or 300Hz. This sound is likely to be badly resonant with a nasty case of comb-filtering. Therefore a smaller box with a 12" speaker is a much safer bet because the box will be pressure-loaded up to a higher frequency so that resonances will hopefully be well outside of the operating range of the speaker.
Pro-audio cones: soft pulp (AKA recycled newspapers), and ribbed to deliberately reduce the break-up frequency. Don't believe me? At high frequencies (at which efficiencies like 98dB/W are quoted) most of the cone behaves like an accordian surround, or a suspension spider - it stretches and contracts and thus resonates. This is far worse than a little bit of harmless THD (distortion, not the drug!). I find speakers with these resonances really tiring to listen to.
Anyway I'm sorry that I can't prove that there are any resonances from 15" pro-audio drivers - I've never managed to find a waterfall plot of one. Perhaps they're so much better than the waterfall plots of hifi speakers that they don't bother?
CM
Wavelength issue: thankfully beaten to death. I'll just twist the knife if I may, by asking: what the heck is a wavelength anyway? Isn't it just an abstract definition of "frequency" by converting it to distance after some rough assumptions about the speed of sound? At 20Hz the measurement accuracy between successive peaks in air-pressure would probably be around +-5 metres. It's really the average time difference between pressure peaks that's important.
Back to 15" drivers:
Box size: huge, too big for anything except LOW BASS. Just like rooms have room-modes, boxes have "box-modes". With a box that's 100L or so, it'll be a struggle to achieve high quality sound even with extreme efforts with damping techniques and materials. If room-modes are considered bad, then what about box-modes that start above 150Hz or so? Even if the walls of the box are perfect and let out no sound, the cone itself will be the source of resonances escaping from inside the box. Personally, I don't know of any material that can absorb frequencies from 150Hz to 400Hz or so and fit inside a 100L box. Even if a 4th-order filter is used at 80Hz, the speaker will still produce some sound at 150Hz or 300Hz. This sound is likely to be badly resonant with a nasty case of comb-filtering. Therefore a smaller box with a 12" speaker is a much safer bet because the box will be pressure-loaded up to a higher frequency so that resonances will hopefully be well outside of the operating range of the speaker.
Pro-audio cones: soft pulp (AKA recycled newspapers), and ribbed to deliberately reduce the break-up frequency. Don't believe me? At high frequencies (at which efficiencies like 98dB/W are quoted) most of the cone behaves like an accordian surround, or a suspension spider - it stretches and contracts and thus resonates. This is far worse than a little bit of harmless THD (distortion, not the drug!
). I find speakers with these resonances really tiring to listen to.Anyway I'm sorry that I can't prove that there are any resonances from 15" pro-audio drivers - I've never managed to find a waterfall plot of one. Perhaps they're so much better than the waterfall plots of hifi speakers that they don't bother?
CM
Konnichiwa,
Not quiet. A drivers step response will change if the BL/mass ratio is changed and I am refering mostly to the initial part of the step, not the settling. This is not as such responsible for "fast bass", but for whatever reasons, drivers with a sufficiently flat response but a poor BL/mass ratio sound "dead" and "slow", IMHO a desult of the "slow" intial edge on transients. Of course, once X-Overs are tyhrown into the mix most bets are off anyway.
This is true to a degree. However, take an otherwise identical driver (fieldcoil?) and adjust the force facto only and observe the transient behaviour. It does change.
AND a fairly favourable (low) Mass/BL ratio.
This has little to do with the precise reproduction of for example a plucked upright bass. Such a bass will sound severely boomy and overblown on certain notes if your suggestion is implemented. It clearly works for a rock kick drum, but not really for acoustic music from the classical and jazz side. And it is with such music the subjective lack of tactility and "speed" is observable with drivers having a too unfavourable mass/BL ratio.
Sayonara
russbryant said:
Not quiet. A drivers step response will change if the BL/mass ratio is changed and I am refering mostly to the initial part of the step, not the settling. This is not as such responsible for "fast bass", but for whatever reasons, drivers with a sufficiently flat response but a poor BL/mass ratio sound "dead" and "slow", IMHO a desult of the "slow" intial edge on transients. Of course, once X-Overs are tyhrown into the mix most bets are off anyway.
russbryant said:
This is true to a degree. However, take an otherwise identical driver (fieldcoil?) and adjust the force facto only and observe the transient behaviour. It does change.
russbryant said:
AND a fairly favourable (low) Mass/BL ratio.
russbryant said:
This has little to do with the precise reproduction of for example a plucked upright bass. Such a bass will sound severely boomy and overblown on certain notes if your suggestion is implemented. It clearly works for a rock kick drum, but not really for acoustic music from the classical and jazz side. And it is with such music the subjective lack of tactility and "speed" is observable with drivers having a too unfavourable mass/BL ratio.
Sayonara
CeramicMan said:
Well, herecomes a hint. I agree that "The Box" is "The Problem". Remove the Box and you remove "The Problem" on several levels.
No box, no standing waves, coloration from flexing walls et at.
Throughout the Modal range of a room a dipole offers a much more even response (by virtue of exciting room modes most when placed in the center of the room and least when in a corner), so you want your woofer system to be a dipole, unless you want to use some form of equalisation.
CeramicMan said:
Yup. And with LARGE boxes these fall pretty low, preferably below the formant range and becomes less of an issue. The "box-modes" of small boxes are smack bang in the upper formant range and also where the ear is most sensitive to them. ;-)
CeramicMan said:
Well, I had not so long ago 230 Liter Boxes (reflex too) made from 1" Solid Wood boards and the result was judged by all that heard the system as outstanding AND free of obvious or even modest colorations. Of course, the whole system was also in room equalised....
CeramicMan said:
Hmmm. You'll get tons of comb filtering anyway, from the room.
CeramicMan said:
As you may or may not be aware, many Pro Audio drivers actually have curvilinear cones without ribs.
CeramicMan said:
As said before, a bad driver is a bad driver, be it 6.5" or 15" in diameter.
CeramicMan said:
You are obviously not looking hard....
CeramicMan said:
No, in many cases (for the better units) the waterfall plots tend to look as good and better than most HiFi Cone Drivers. Sadly all of what I have available is copyrighted material, which hence cannot be posted here. You may wish to purchase a few issues of the German "Klang + Ton" mag and some from "Hobby HiFi" (also german), both regulary test lartge numbers of drivers, all with waterfalls and with quite a few Pro Audio drivers thrown in for good measure. The tested Beyma 15" Coax drivers for example looked rather good in waterfall plots....
Sayonara
Add mass to a driver and measure the response and you will see this is not correct.Kuei Yang Wang said:
A musical transient is by it's nature made up of many frequencies many of which are not handled by the bass driver. If what you hear can be described as being slow it's not because the driver couldn't move fast enough. How fast a driver can move affects it's high frequency response not the low end.
Kuei Yang Wang said:
I don't follow. How do you change the only the flux density (B) assuming the length (L) is fixed? I'm not saying it can't be done, I just don't know enough about it. I was under the impression that BL was a constant (excluding nonlinearities due to cone motion as it moves the voicecoil out of the gap).
Kuei Yang Wang said:
Agreed, and yes I was thinking of the kick drum. This was only to point out the frequency range of where that chest pounding bass is, i.e. not low bass.
russbryant said:
KY contributes a lot here, so I'll pitch in on this one and save him the effort, cause it's simple enough for me. The field coil he is referring to is the use of an electromagnet for the driver motor, instead of the usual permanent magnet. The flux density is changed by simply changing the voltage to the magnet's coil. All the other parameters, of course, remain the same as before. Fertin and Supravox are two makers that offer such units. Handy, at least in theory, as you can change the Qt of the driver to optimize alignment.
Sheldon
Man, when are some of you people going to wise up and stop pretending to know everything about everything?!
15 inch drivers are slow..... BULLS***!
15 inch drivers can't play bass at low volumes...... BULLS***!
15 inch drivers need huge XMax to produce bass...... BULLS***!
15 inch drivers are overkill...... BULLS***!
15 inch drivers only sound good at high volumes...... BULLS***!
15 inch drivers with high efficiency can't produce low bass..... BULLS***!
Only low efficiency 15 inch drivers can produce low bass...... BULLS***!
You can't hear 20Hz in a certain size room..... BULLS***!
I could easily keep going here, but it's already 2:00 in the morning and I'm tired of typing the word "BULLS***".
I have several organ CDs with 64' open diapasons and 32' stopped diapasons, that's 8 to 16Hz, and my dipoles are capable of creating most of that at any volume level. Of coarse, it's more fun listening to it at real levels.
You can argue with me on this all day long about why my system CAN'T do this, that it's impossible. Well, I have the living proof right here in front of me every day!! If you don't believe me, then go out and spend 150 bucks on these same drivers and build these freakin' things yourself. Maybe if you do, you'll shut up for a while and let the rest of us go about our business!
15 inch drivers are slow..... BULLS***!
15 inch drivers can't play bass at low volumes...... BULLS***!
15 inch drivers need huge XMax to produce bass...... BULLS***!
15 inch drivers are overkill...... BULLS***!
15 inch drivers only sound good at high volumes...... BULLS***!
15 inch drivers with high efficiency can't produce low bass..... BULLS***!
Only low efficiency 15 inch drivers can produce low bass...... BULLS***!
You can't hear 20Hz in a certain size room..... BULLS***!
I could easily keep going here, but it's already 2:00 in the morning and I'm tired of typing the word "BULLS***".
I have several organ CDs with 64' open diapasons and 32' stopped diapasons, that's 8 to 16Hz, and my dipoles are capable of creating most of that at any volume level. Of coarse, it's more fun listening to it at real levels.
You can argue with me on this all day long about why my system CAN'T do this, that it's impossible. Well, I have the living proof right here in front of me every day!! If you don't believe me, then go out and spend 150 bucks on these same drivers and build these freakin' things yourself. Maybe if you do, you'll shut up for a while and let the rest of us go about our business!
It may remove some problems but introduces others, such as reduced sensitivity and much higher cone excursion for the same output volume at low frequencies. This results in higher distortion and related issues.Kuei Yang Wang said:
Box-modes
This has already been covered with the discussion about wavelengths and room sizes. It is a known fact that a relatively small box will be pressure-loaded up to a higher frequency than a larger box (assuming reasonable constraints on the shape of the box), thereby reducing the need for a steep crossover at a low frequency. You said yourself about box resonances that "with LARGE boxes these fall pretty low...." Surely you agree then that these low-frequency resonances would degrade performance compared with a relatively small box?
If the lowest resonance in a 100L box with a 15" driver is at 190Hz, how does this compare with the lowest resonance at 230Hz in a 50L box with a 12" speaker? Or at even higher frequencies with multiple 10" speakers in multiple boxes? Besides, what can a 15" speaker do that multiple smaller speakers can't do?
CM
Konnichiwa,
This works equally as my solution to lower lower flux (and as I did actually do this a while back) and shows a similarly slowed initial slope on a step response.
Note, I am not at all looking at this from an angle of "sinewaves", as such do not exist in Music (Fourier analysis is only valid for a non-changing, infinitly long piece of signal - applying it to transient signals produces misleading results).
You assume the presence of Filters (pretty high order too. As I wrote, if you do that all bets are off.
But chest pounding bass is not an issue when this "speed" thing is raised. I was pointing out that the one and the other have no correlation.
Sayonara
russbryant said:
This works equally as my solution to lower lower flux (and as I did actually do this a while back) and shows a similarly slowed initial slope on a step response.
Note, I am not at all looking at this from an angle of "sinewaves", as such do not exist in Music (Fourier analysis is only valid for a non-changing, infinitly long piece of signal - applying it to transient signals produces misleading results).
russbryant said:
You assume the presence of Filters (pretty high order too. As I wrote, if you do that all bets are off.
russbryant said:
But chest pounding bass is not an issue when this "speed" thing is raised. I was pointing out that the one and the other have no correlation.
Sayonara
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