So true. Tom has a pithy way of expressing things that I like.Magnetar said:
Picked up a bunch of JBL 2225 this morning as midbasses for my bedroom system.
Well, the true sound from a drumskin may actually be very difficult to get absolutely right
Its dry yet with prolonged ringing, its BIG yet also tight and precise...I believe only the best speakers can do that properly and if XO is flawed it doesnt matter how good your drivers are...XO is exstremely important to achieve that
Its dry yet with prolonged ringing, its BIG yet also tight and precise...I believe only the best speakers can do that properly and if XO is flawed it doesnt matter how good your drivers are...XO is exstremely important to achieve that
nice looking basket - guess you were prepared to boost/eq the bottom - did seller give parameters? heres some discussion on them as guitar speaker
http://www.carvinbbs.com/viewtopic.php?p=7368&sid=14747db574973b2d49770dcb548e2cab
http://www.carvinbbs.com/viewtopic.php?p=7368&sid=14747db574973b2d49770dcb548e2cab
freddi said:
It would have needed a touch of EQ
DELTALITE®-II 2512
SPECIFICATION
Nominal Basket Diameter 12", 304.8mm
Nominal Impedance* 8 ohms
Power Rating
Watts 250W
Music Program 500W
Resonance 37Hz
Usable Frequency Range 48Hz-4kHz
Sensitivity*** 99.9
Magnet Weight 7 oz.
Gap Height 0.275", 7mm
Voice Coil Diameter 2.5", 63.5mm
THIELE & SMALL PARAMETERS
Resonant Frequency (fs) 37Hz
DC Resistance (Re) 5.04
Coil Inductance (Le) 0.46mH
Mechanical Q (Qms) 3.13
Electromagnetic Q (Qes) 0.44
Total Q (Qts) 0.39
Compliance Equivalent Volume (Vas) 147 liters / 5.2 cu.ft.
Peak Diaphragm Displacement Volume (Vd) 255cc
Mechanical Compliance of Suspension (Cms) 0.38mm/N
BL Product (BL) 11.3 T-M
Diaphram Mass inc. Airload (Mms) 49 grams
Efficiency Bandwidth Product (EBP) 84
Maximum Linear Excursion (Xmax) 4.9mm
Surface Area of Cone (Sd) 519.5 cm2
Maximum Mechanical Limit (Xlim) 8.5mm
freddi said:
I didn't see any for that price - the 16 ohm are under half price.
Too bad the Madisons aren't available for 12 bucks! I should have bought all of them.
I've got one 8ohm Madison - its cone and surround are real good - seem like shipping was about as much as the drivers- -I've run outta room to have any more speakers or use the ones I got -- wonder how ch2010 would play?
MaVo said:
This is too simplistic, all I did was answer your specific Q, there's all the other requirements that makes up the 'all else being equal' part that Magnetar elaborated on.
WRT the headphones, they are such low efficiency/physically small that there's no way they can handle much power, ergo limited dynamics even at such a short listening distance.
WRT the guitar, it's next to impossible to find uncompressed, ultra wide BW recordings, so any high amplitude transients and sub-harmonics are damped to a greater or lesser extent so they can be reproduced at fairly loud SPL by a low efficiency, limited BW system.
Note too that even if you don't EQ the signal at all and the playback system can handle a 40+ octave BW, there's still the problem of the microphone's inability to accurately capture all of the signal and why the original 'stereo' system was three channel as the minimum acceptable to reproduce the mic's/speaker system's ~ flat 50 - 10 kHz BW ~accurately.
What really shows how problematic multiple instrument recording is, the pioneers of audio resorted to attaching a huge horn to the mic and the players/singers all huddled as close as they could to each other and the horn's mouth to try to capture as much as they could for early mono recordings.
Folks like me prefer systems that allows us to as accurately as practical reproduce all the recording has to offer with the understanding that even reproducing a single instrument accurately at live levels is for the most part a 'pipe dream' due to the recording system's limitations, not to mention the size/cost of such reproduction systems.
GM
ROTFLMAO ! wait til i patent the karlson KrPpLe
Reggie Van Gleason III
http://www.youtube.com/watch?v=89aAT6iZero
Reggie Van Gleason III
http://www.youtube.com/watch?v=89aAT6iZero
Magnetar said:
Sound reproduction is basically about moving air, so if tweeters/whatever had enough linear excursion/thermal power handling to move as much air as a large planar panel they would actually be more accurate reproducers due to them being a point source over a much wider BW and why I now recommend using several high power/excursion low Fs 'sub' drivers in IBs rather than large/complex construction horns.
GM
GM said:
Point Source - My best shot at that was with the TAD compression driver in the 180 hz horns - beamed badly but man it produced goose bumps on goose bumps with the right amp and recording if you didn't move your head....... they did 250-300 to 20K
I don't get the point source part and the multiple woofers where you say the opposite though! A 100 db plus sensitive neo magnet planar for mid bass is where I want to be someday.
How would you define a point source in bass? Seems to me if they are within 1/4 wavelength apart they are a point source. I have clustered multiple bass drivers and if crossed over low enough they act as one BUT can be configured to alter the radiation pattern. This can be a good thing, then use them as dipoles and they radiate a figure eight plus no longer have the resonant 'box' sound - for deep bass use a horn or your multiple bass drivers loaded in corners..
A horn isn't a point source until it can no longer control directivity while a direct radiator is one until the WLs are small compared to its Sd, so even several 15" will be a point source to a much higher frequency than an equivalent BW horn.
That said, this assumes a traditional horn. A tapped horn such as DSL's DTS-20 which has an acoustic radiator that's quite small as sub systems, especially horns, go is a point source to a higher frequency than an equivalent FLH. This was the first thing I noticed about it during my audition, the bass was everywhere, like at a live event. Of course we were in a warehouse that I'm guessing is about the size of a typical cinema, so this helped a bunch too.
GM
That said, this assumes a traditional horn. A tapped horn such as DSL's DTS-20 which has an acoustic radiator that's quite small as sub systems, especially horns, go is a point source to a higher frequency than an equivalent FLH. This was the first thing I noticed about it during my audition, the bass was everywhere, like at a live event. Of course we were in a warehouse that I'm guessing is about the size of a typical cinema, so this helped a bunch too.
GM
So a point source is one with no directionality? Must it be a single point 360 degree radiating sphere? My experiments with drivers 'trying' to do this, sound too much like the room and not enough like the recording. I find directional control is a real benefit with a loudspeaker used in a persons home. I know what you mean by live bass having the sensation of being all around you. I call that 'free' sound- in my room directional dipole bass actually sounds more 'free' as in live. I think if you take the tapped horn and use it for midbass in your room you will not get this free sound. The fact it was in a large auditorium is why it was free.
hi GM - by that definition, couldn't a well-designed bandpass box be a contender - at least in a reasonable size room?
freddi said:
Does one even exist? The one's I've heard all sound like one note fart boxes. I think this definition of 'point source' bass is just another name for a monople.
ask Geddes - I tried a pair of 170l bp4 to "help" AR M1 - no xover - didn't boom much -- up course no upper bass dynamics with a weak 6.5" woofer
Magnetar said:
Correct.
No, just its radiating area be greater than the WLs being reproduced, so for a ~15" frame driver this equates to ~1 kHz before it begins beaming.
For WLs smaller in size than our heads I agree that the right amount of directivity for the app required is desirable as it takes the room ~out of the perceived SQ 'equation', though for a realistic reproduction it's not desirable since you don't see a horn attached to a guitar/whatever.
Anyway, below this point we ideally want to have a ~uniform particle density, i.e. sound everywhere to get the spaciousness of a large venue and down low the only way I know to get that is with multiple subs scattered around the room as Geddes and a few others recommend. The mid-bass/lower mids is the transition BW and the rate of transition is room/speaker placement WRT the listening position dependent and one reason why dipoles are popular in typical size rooms, with the main reason being it's an acoustically balanced alignment, same as a reactance annulled horn, its technical extreme, both providing an effortless presentation within its linear BW.
The two tapped horns were XO'd to seamlessly mate to DSL's three way Unity, so I assume around 80 Hz, but don't have a clue.
WRT using a tapped horn higher up, this came up recently on the collaborative tapped horn thread and my SWAG was it doesn't seem a good idea, at least with the simple pipe horns Hornresp can sim. A true compression loaded tapped horn like I assume the DTS-20 is might work just fine, but I'm still in no position to experiment to find out and don't want to take the time to learn Akabak well enough to sim one.
GM
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