Eh, whisky is for the stratospheric folks, we all know that the finest rums drive beautiful bass, especially when its striped a lil red. And its called a chillum boy 😉
The amp that I was trying to break it in with had died. Then I packed all the project stuff away under the Heaving Bed to build a new workstation studio desk in that area. It's a very tiny space and needs some attention. Also welded up a metal frame to be the porch cutting bench. I have a bit of form ply in the offcuts to use on this as a top. I also have to take out the work area that I built before the baby was born. I have been kicked out of that room! And taking my mixers and synths with me to the new area. And the 58" screen 😀
And I have a feeling that you will be very interested in the lot of obscure drivers that I have piled up to put through the DATSv3. These are mostly from OEM'ers and some are clones of drivers that aren't available to buy as parts. I can't work with the clutter from the ongoing renovations work. Patience man, soon come
Randy, you have been approached fairly, but you also made mockery of our attempts to explain, knowingly or unknowingly.
I might be mistaken, but to date I have seen no math and no measurements. That's not a study.
I feel being the one bullied along with the rest of the bunch trying to explain things before. Being disagreeable or dismissive is no bullying, if we are not talking facts, but opinions and subjective experiences. We approached the topic with mostly curiosity and good will to dig into it. I did. But it went all downhill at some point.
I would stand down indeed, but as you are finished with the discussion, there is no point.
I might be mistaken, but to date I have seen no math and no measurements. That's not a study.
I feel being the one bullied along with the rest of the bunch trying to explain things before. Being disagreeable or dismissive is no bullying, if we are not talking facts, but opinions and subjective experiences. We approached the topic with mostly curiosity and good will to dig into it. I did. But it went all downhill at some point.
I would stand down indeed, but as you are finished with the discussion, there is no point.
Crash, why would you say that? I keep trying to point out that I am discussing a non mainstream class of souped up sound quality drivers and band and stage instruments while the participants keep instead referring in a derisive manner to the one note SPL type systems even though those aren’t daily driver cars
Thats definitely not fair dealing. No one has any first hand knowledge of this particular class of drivers anyway except for the anecdote from Art where he pointed an RTA at a passing car that was showing up his PA a bit
No one willing to apply focus on why drivers with such dismal efficiency ratings of below 85dB get so much louder even then a more efficient driver of the same size in the same vehicle. How does that not kill any discussion?
Thats definitely not fair dealing. No one has any first hand knowledge of this particular class of drivers anyway except for the anecdote from Art where he pointed an RTA at a passing car that was showing up his PA a bit
No one willing to apply focus on why drivers with such dismal efficiency ratings of below 85dB get so much louder even then a more efficient driver of the same size in the same vehicle. How does that not kill any discussion?
Basically, the 85dB driver has more xmax and can handle more power than a typical PA driver. Plus, you have transfer function.
I have seen quite a few car installations and most of them were low Q drivers tuned with more or less ridiculous peak. So I cannot agree on that one.
The PA problematics is deeper. Actually many 12" PA drivers are not sensitive in 40-50Hz range. These are not even much more efficient, and on top of that the higher impedance doesn't allow the car amp to drive it properly quite often.
We did focus on that. We presented our data and opinions, and it was somewhat "overlooked or dismissed or ignored" and now we are in a circular argument for which we are called bullies. No wonder people lost interest, this is not a way to conduct a topic. You have great thing on your hand but you keep it subjective to a point of ridiculousness. How about particular CASE comparison. Say 12TBX100 vs MXZ-12D2. I had these, and I have good reason thinking that the TBX would not exactly win.
You continue to mistakenly conflate "efficiency", the ratio of electrical vs acoustic watts, with sensitivity ratings, which makes "discussion" futile.
I don't recall an efficiency rating ever used for a raw low frequency driver.
Manufacturers would not be inclined to post their 85dB 1W/1m sensitivity drivers have under two tenths of one percent (0.199%) efficiency in their upper pass band, and a small fraction of that tiny percentage in the low bass range.
No one?
Almost every body near a road living in this century has heard booming car bass produced by high mass, high excursion drivers.
I wrote "I could see on my RTA the car subs output was easily 12dB louder in the 25-40Hz range than my PA, and matched it in the 50-60Hz range."
The EVX-150A drivers used in my 15" short horn bass bins rated sensitivity is 98dB (SPL at 1W/1m, 100-800Hz average).
"A bit", would be a few dB, 12dB is more than an order of magnitude (10 times the power).
In the 25-40Hz range, a 12dB increase sounds almost four times as loud.
The car driving around the plaza was equidistant (or further) from my mix position (where the RTA mic was) to the PA's distance.
There is no question that the car's low bass had more SPL down low.
Also no question the car had considerably more enclosed volume than the four PA bins.
It should be obvious that typical subwoofer "sensitivity" ratings and low bass output when in a car have little to do with each other.
Art
My bad, you are right, sensitivity is better used
This is apparent for experience with SPL drivers, as per all disputes in the thread. At some point I do hope someone will drop the boom car and look at the thup thup thup ones. Please have a listen to the African dub child. This kick has no boom and we should try to stick to topic and these are the good installs that do not add a boom
My local scene from back in the day might not be typical. The inner west suburbs mostly had car installs done by just one person who was very much into very high sound quality installs. Allow me to yet once again try to steer this away from the SPL drivers playing sine waves. The question was not about them, and it would have been much appreciated if everyone would recognise that point. I am using the JLAudio 12W7 driver as the example, at its introduction, this was the only driver in Au that could go low and loud without giving much away to the SPL installs. The SPL installs are louder, but not relevant to the topic. The question is regarding music quality drivers of the t-rex kind and not the SPL drivers of the t-rex kind
I tire of pressing this point any longer. Discussion is futile if you will not take the time to consider the type of driver in question and only focused on the type that is not in question
Here, if I say, 'Hamm it's a bit hot today', assume that those kangaroos that you folks know off as always running down our streets are on fire 😉
Or I might be fishing off the pier and get asking, "getting any bites?" and respond 'a bit', while trying to stop a 20kg GT trying to tie me in knots amongst the pylons
I hope that makes 'a bit' more sense, it's a regional differences thing
Now, this is a great point in time for something. Here are how I would typically respond back to a response. I have felt that the response was addressing something that is not the item being asked about. This is pretty typical from page one. Is this what you folks are calling as making a mockery of explanations given? Or is it the fact that I would stand up to the personal remarks?
When I raise a question re a particular point in a response, it is said that I am disputing the explanation given. Let's instead try something different. Let's try a question again as I have one but this time, let's all do something different and take it as a genuine desire to explore that point further
I find this as an explanation to fail to recognise the question. Can we expand on this to the question of which in my last point was of comparing a higher sensitivity driver of the same diameter
And when not in the car
But, zero confidence that a dialogue can be had regarding the actual subject of the topic
I don't understand what your question is.
A higher sensitivity driver may require less power to reach it's Xmax, but more displacement ultimately makes for louder low bass. Car subs generally have far more displacement than PA subs using the same diameter drivers.
The car's cabin is a huge, secondary bandpass enclosure.
The cars windows are bandpass ports when open.
Sections of sheet metal (and glass) are huge passive radiators, also known as "drone cones".
Whether a kick has or has no boom, once the resonator is excited, it's takes a while to stop, and that may be longer than the duration between beats.
If you determined the equivalent TS parameters for those resonators, and the Fb of windows (open or closed) you could model the net effect of their bandpass output, which can add 10-20dB ("a bit", like the difference between 1 and 1000 watts, or 1 and 200 meters 😎 ) to the direct radiated power of a car subwoofer at various frequencies.
Having already heard (and measured) the re-radiated output of car sub woofers, I wouldn't bother trying to model it, but it is no mystery why they can be so loud.
That said, even though car subwoofers output has increased over the years, the newer cars they are in often have far better soundproofing than the ones you can hear coming from blocks away.
Art
Art, this type of explanation as to why the cars are loud and dispersion as to why the PAs are quieter is now has been mulled over and accepted all the way from page 1-10
Let's try to keep steering away from that to
A lil mod to that, let's remove the PA driver from the equation, that's been explained and accepted and packed up and put away much earlier. Instead, the new dispute appears to be regarding my musings on comparing drivers on hand and not yet acquired. So, in that I am looking at car subs vs pro mobile SQ drivers (Difference is hi-fi type assemblies and Xmax and higher Vas vs pro sound type assemblies and crazy Xmax)
Also looking at another driver that is no what I would place in the 'pro' class, but it has a version which fits just under the pro streams. The bridging driver is just about exactly twice the magnet and coils as the forementioned base consumer model. But it is not twice the cone mass and the moving mass increase only comes from the doubled coil and changes to accommodate that. This beefed up driver has much higher Fs and a lil lower Vas and sensitivity then the base driver and forms the basis of the SPL models in the SPL ranges with larger surrounds and power as the price goes up
The two SQ streams also follow the beefing up, but there is no base model, these have much larger magnets in both diameter and depth as well as much greater cone mass and stiff surrounds and longer excursion. I can't help but see one as having twice the motor as would normally be on a chassis this size and 4 times as much on the other. Reports on these two ranges are comparable to the JLAudio W6 and W7 streams
I can't help but wonder if JLAudio modelled the performance of an isobaric pair into a singe driver, and modelled the performance of two such pairs into a single driver for the W7. It hurts no one for me to ponder like this and that is what I would rather do than ponder over the ugliness that seems to have been prompted by my continued stating that the point has been discussed and accepted and continued requests to let that go and instead turn the attention to the driver type and how it stands apart from others in that same Sd size
Kicker did offer this as the reason for using the Solobaric name for their product. The Z series from DS18 appear to be inspired by the JLAudio W6 and W7
In the original article that I read on the Sunfire over half a lifetime ago, there was a statement that I might not be remembering correctly, as it may have been further elaborated post article by the author. What I remember being said was that the active driver displaces as much air as 4x 15" JLB subwoofer drivers (they didn't state the model) and talked about making good use of an amps dynamic power and discussed things like back EMF from such motors and more that was beyond what I could understand
Unfortunately, the concept never really got taken up or further apart from the JLAudio Gotham and Fathom, as well as more basic attempts from Logitech. The car industry welcomed and accept these drivers as we finally got to use the boot for shopping too. How to get the best and design around these were pretty much the domain of installers like my old friend from school. Everyone else just made the stock box in the manual
One of these drivers has been a constant companion for half of my life. Very much loved and appreciated for the joy in music it's been allowing. Definitely interested in learning about everything that makes this driver type tick
What say, can we finally go examining in detail as to. "What makes them louder and beautiful" from, "Which one is louder". May I say again, PA is now resting and waiting to be unleashed from its cardioid restraints. And now let's finally take the box out of the car to give it a haemorrhoid (handicap). Folks are failing to recognise that we already went one to one with a probably an ETX18
I'll find some speaker wire and go back to the ramp to get a box out of the car reading with the kick in African dub child and Volcano. At the moment I only have the Yamaha AG06mk2, Bheringer calibrated condenser, the Protégé X30-J and ARTA/REW or the iPhone APP. The bench stuff will be first use, so not sure about best practices and such
Our out/looks are so different. Feasible car audio was junk around me in past. Finally these companies made linear and strong motors enough to rival quite few PA speakers, but outdoing them in more linear displacement, but for ridiculous prices. Then no wonder the exensive driver with lot of cone displacement will outdo PA speaker, but for what price... And while PA didn't and doesn't have anything similar in 12" size, it can be considered outclassed indeed. But at these prices, PA can get you 15" or 18" and at that moment it has enough displacement volume again.
When I look at local car audio shops, there is nothing that would outdo chosen PA drivers price for price.
And so chosing superior, "superiorly priced" product against is is like "DOH" moment to me. Obvious.
Continued, on your approach: indeed it can be historically done that way, but in times of modern processing and enough amp power, we really can afford to look at it through the lens of displacement volume and motor force, while almost ignoring the rest. Nothing else really matters. We can compare speakers this bluntly for preliminary evaluations. Maybe let's do that and let's see what we can get on current market.
Looking at Kicker, it seems "they're done" and looking at JL Audio, the speaker that would outdo the RCF LF18X451 for $500 by cone displacement costs $1800, by which we can substitute by 21" beasts that would put stop to anything JL audio was thinking it was doing.
So yeah, let's bring on some particular cases.
When I look at local car audio shops, there is nothing that would outdo chosen PA drivers price for price.
And so chosing superior, "superiorly priced" product against is is like "DOH" moment to me. Obvious.
Continued, on your approach: indeed it can be historically done that way, but in times of modern processing and enough amp power, we really can afford to look at it through the lens of displacement volume and motor force, while almost ignoring the rest. Nothing else really matters. We can compare speakers this bluntly for preliminary evaluations. Maybe let's do that and let's see what we can get on current market.
Looking at Kicker, it seems "they're done" and looking at JL Audio, the speaker that would outdo the RCF LF18X451 for $500 by cone displacement costs $1800, by which we can substitute by 21" beasts that would put stop to anything JL audio was thinking it was doing.
So yeah, let's bring on some particular cases.
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That is what my novice level understanding of various cabinet types (sealed, ported, bandpass, etc) thought I had figured out kind of.
In my SUV, I can crack open the rear driver's side window about an inch or so (all others are closed because I don't want to bother others on the freeway) and I know it isn't any air turbulence noise making the treble sound lesser and the bass (the sub in the trunk) louder. The sub just seemed 'free'er' to do its thing.
Then again, I did seal up the SUV so well that sensitive ears of friends can sometimes 'pop' (feel the pressure change) when the last person closes their door. That was only to enhance the weatherstripping's job by using double-sided nylon - acrylic? - tape under the stripping and then RTV carefully sculpted around the stripping to 'body' just for good measure. I haven't had anything show any kind of rusting (and no water pooling either - I made sure of that as moisture must drain somehow) so it has been a success to eliminate any and all whispers of air trying to ruin my sound.
I see (hear) the situation as 'sitting within a speaker' that is a bandpass enclosure and has midranges and tweeters inside of it too. 🙂
Well I hope you can see my point now. The article on the Gotham (contains a pair of 13W7s) was pretty black and white, with the conclusion that their studio sub getting replaced by it. I can no longer afford to pay for a W7 driver and I need four such. The 'why' was well covered in another thread. If I can learn what makes the 12W7 tick, I can then hope to choose alternatives to bring in for auditioning without wasting too much money
Currently, the working with the ZXI12.4D as a likely candidate. The ZXI has been put forward to me as the one to beat the JL but in my noob hands, I cannot be confident of a true eval due to not being confident with doing the driver justice in measuring it and making a decent enough box to audition it. The specs on this has an anomaly which makes them unreliable. The driver has a reputation for doing very well in the car. I want to see if it can do so out of it. It is more formidable than the W7, but nothing like the SPL drivers
If this driver works out, I'll save a $1000 per driver. But all this is moot. My thread where I requested help with finding a likely driver didn't produce any candidates, and selecting the ZXI was done through scouring the catalogues and speaking with contacts. That thread is still there if anyone has any interest in what it can do after I put it through its paces
I mean we have totally failed to study the driver type for 10 pages, a particular driver had no hope in the face of that. Not even the premium JL
Totally agree, but if you look at the original thread. There is a valid case for the most constraining aspect being the total size for transport and storage. In this situation the existing pair of 15s have been traded for a 10hp Mariner 2st, 18s and 21s have no chance. But this is me going off-topic again. I was hoping to explore driver type
Well, I just remembered one funny vid:
(start at 2:30)
As of now rather offtopic, but with good headphones or larger audio, it shakes the ground when I play it, and it FEELS like this is certainly not weaker sounding than typical 12"-15" mid-high range car install. The bass sounds clean, with wide range, strong as heck. Never heard such thing from a car. Just "one note HHHOOOOH booom".
Sorry for OT, I´m done here hehe.
I was looking for car audio drivers again, gave it over two hours. Nope. No solution in fair money that would be better. Only expensive stuff at around 1600-1800USD, which is ridiculous. And I wanted. I really wanted to use 8 car audio drivers instead of PA. But not feasible. In budget class, it would be somewhat doable with 16 units, but it would be headache with amount of boxes, series-parallel connection compromises, lugging all of that around and such.
So I am sorry, but I don´ t see a way how to be helpful. Will just wishingly chime in on such topics here and there in hope that there is something new that breaks this circle.
As of now rather offtopic, but with good headphones or larger audio, it shakes the ground when I play it, and it FEELS like this is certainly not weaker sounding than typical 12"-15" mid-high range car install. The bass sounds clean, with wide range, strong as heck. Never heard such thing from a car. Just "one note HHHOOOOH booom".
Sorry for OT, I´m done here hehe.
I was looking for car audio drivers again, gave it over two hours. Nope. No solution in fair money that would be better. Only expensive stuff at around 1600-1800USD, which is ridiculous. And I wanted. I really wanted to use 8 car audio drivers instead of PA. But not feasible. In budget class, it would be somewhat doable with 16 units, but it would be headache with amount of boxes, series-parallel connection compromises, lugging all of that around and such.
So I am sorry, but I don´ t see a way how to be helpful. Will just wishingly chime in on such topics here and there in hope that there is something new that breaks this circle.
Back in the 1990s, most JBL woofers were in the 3 to 8mm Xmax range with Vas too large to work well in small enclosures.
The 1.7 pound moving weight Sunfire passive radiator had around 2.5 inch peak to peak displacement, 31mm, so could have the displacement of four 15".
The high excursion Sunfire active driver was able to handle the peak voltage (equivalent to 2700 watts) the efficient switching power supply "Tracking Downconverter" amplifier could deliver.
Because of those features the Sunfire "True Subwoofer" in under a cubic foot could put out more level below 40Hz than most drivers 30 years ago.
That driver certainly has a good displacement to cost ratio.
Like the Sunfire, it will require lots of peak power to utilize the displacement.
Is this class h? If I remember the datasheet from a high end systems builder who supplies the modules to Logitech, the z623 uses both class h and I or something and embedded fixed DSP. I always feel that there is much greater power peaks then the 140wrms rating for the sub channel. Reviews are always limited to the person's ability to benchmark, but this is one of the better ones by someone who seems to know what they are doing
https://hometheaterhifi.com/blogs/logitech-z623-2-1-speaker-system-review/
Art, it's now 30 years later and that cubic foot is getting company one way or another with the Volcano. I think it's feasible with the work I have done in bringing together the parts
I can afford to give it 1.4kw reputable dynamic power using Eric's 600wrms mono module per coil
Will try to get my hands on a Sunfire driver. Will have sentimental value on display in the workshop/audio area and study it first hand. When the publisher of the hi-fi mag had Sunfire ads, his car audio mag started showing ads for a totally crazy looking driver (around 5yrs prior to W7). I cant remember if the brand was Ground Zero or Sun Down or Sand Down or something similar. They had gold-plated baskets and roll surrounds that seemed more roll than cone as well has huge magnets. There was nothing like them around at that time other than the Sunfire and they appeared together. Maybe the OEM?
These were the items of fantasy for a youth trying to find a system that did basslines and could fit in his bedroom and also be used for work for the aspiring DJ/ Ragga vocalist........30yrs later still chasing the fantasy but have come close with the car and smaller Logitech's spread around
We are all here for our love of music and music making things, and I hope some of the guys can drop the attitude and appreciate my efforts and help perfect the testing and such or observe with a polite smile or a quiet sneer
Class H amplifiers modulate the supply voltage to the amplifier output devices so that it is never higher than necessary to support the signal swing.
Bob Carver's "Tracking Downconverter" circuit description sounds similar to that:
Class D amps are now more efficient, weigh and cost less than class H.
Many are also showing as slightly under the certified and uncertified power tests results when tested for dynamic power on the SMD amp dyno
Hence, the important point I made about the modules that I selected which have awesome dynamic ability
In the case of the Z623, the amp pretty much takes up all the space in the cab. Much larger than class D. The subsection is discrete class AB and mains are TDA7293 pair. The PSU is not the transformer type or normal switching type. According to the document, it's based in class h and i. There is more potential than 30wrms rating on the mains
I still get excited about noticing details and differences in various things. I would like to contribute to the actual topic by saying that one part of getting results out of the SQ pro mobile driver class is it to ensure the amp is of sufficient power. For a driver like the 12W7, at least 2kw dynamic is a good start. My 1kwrms amp cant do this and it's noticeable
The other lil thing that I raised was what I noticed re Bob Carver's mentions of back EMF with these types of drivers.....I don't feel I have come across this being explored and further studied. The motor structure of these drivers are significant, it may pay not to brush off this aspect either