Fs............21.30hz
Qts..........0.41
Qms........5.35
Qes.........0.45
Vas.........338 L
Xmax.......18 mm
Re............2.7 Ohm
Pe............500 (continuous) (thermal)
Sd.............825 sqcm
Le.............0.3 mH
Bl..............11.1 Tm
SPL...........90.65 dB
The Acoustic Elegance SBP15-4 is the successor to the presently retired IB15 series of infinite baffle subwoofers. Each sub is hand-built by John Janowitz as it is ordered – for those of you who are frustrated from having not received your sub(s) yet, keep this in mind.
I ordered the sub last July from John and was fortunate enough to receive one of the first SBPs that were made. Unfortunately I had the sub sitting in its box since September of last year, but it has since been installed in my car in January 2012. After nearly four months of playing time, I’d be lying if I said I had any complaints thus far.
I know many of you are waiting eagerly on your own pair of these subs, and since it appears to be taking some time, I hope to be able to give you more insight into what exactly you are about to receive. I will say this, it is worth the wait.
It's a bit of a read, but there is much to praise.
Transient response. Despite pushing the sub to its limit, the SBP-15 has never shown signs of lethargy. A good example of this is Brombo, by Brian Brombers and Akira Jimbo. The song consists of a drum set and bass, but I only listened to the first 1.5 minutes in which there is a solo drum set. The pace is quick and the drummer is really slamming on the drums which make for a strong, hard-hitting bass impact from the kick drum. The AE handles this with great ease, never missing a beat. You can clearly hear and feel each separate impact’s attack and decay from one beat to the next. The sub does an outstanding job of playing only what it is told to play and nothing more – there is no overhang or muddiness. Due to its lightweight paper cone and stronger motor (over the IB15), I have yet to hear a song where sub bass accuracy hasn’t lived up to expectation.
Efficiency. Simply because the sub is infinite baffle doesn’t mean it can’t get loud. I am giving my SBP15 the rated 500w. With the right EQ, I have found the sub is very capable of being almost overwhelming – if you so wish to make it. I am no super-heavy basshead, but I have found it surprisingly easy to get a single infinite-baffle 15” to go from a normal listening level to holy-shit-turn-it-down loud with very little adjustments.
That said, I’m now going to compare the SBP15-4 to the McLaren MP4-12C. And here’s why: the McLaren is an incredibly well-built sports car that performs outstandingly on the open track, and it is also a VERY forgiving machine. There are so many electronic safety controls you have to purposely turn off to really endanger yourself or the car. Otherwise, if you make a mistake, the technology is there to save your butt. The SBP15 is similarly a VERY forgiving subwoofer. You can, of course, make it sound bad, but that has got to be your ultimate goal. Barring that, it’s hard to make the sub sound bad even with EQ flops. For example, boost it too much and it will still sound clean and composed. It seems counterintuitive, but that has been my experience.
Low frequency extension. The sub plays cleanly well into the low sub bass frequencies without distortion. A fine example of this is Bass I Love You – the song dips down below 10hz. While watching and listening to the single SBP15 at high volume, there was NO distortion, each cycle is still felt independently and the driver showed no signs of struggle or strain – it was happy doing its thing.
Sub-to-midbass transition. Since demoing the sub’s abilities, I’ve had numerous listeners give their compliments to the sub-to-midbass transition. As I mentioned above, the SBP15 has no trouble blending seamlessly into your midbass range. Even crossed at 120hz I was surprised at how well the transition blended together.
Summary:
The sub can handle anything you throw at it, from Brad Paisley’s I Wish You’d Stay, to the extreme lows of an organ, to fast-paced, hard-hitting dubstep and everything in between. The kick drum in Alice in Chains’ No Excuses will hit you so hard it is painful. The sub always moves with authority. In Metallica’s One, the double-bass towards the final half of the song are clear and extremely distinguishable – you can hear and feel each full, individual strike of the drum in perfect time. Limit to Your Love by James Blake begins abruptly with absurdly quick pulsating bass, which the SBP keeps up with perfectly. When the pulsating stops on a dime, so does the sub. This song is a magnificent test for any subwoofer, and the sub passes it with flying colors.
As is with any rear subwoofer, without time alignment, lower notes will of course reveal the location. With proper time alignment, this only occurs with drawn-out low frequencies and the great majority of the time you will forget the sub is even back there.
I will summarize this long post to say this: although the SBP15-4 was only my second subwoofer, it will without a doubt be my last.
Here's the sub installed in my trunk:
05 Monte Carlo - kick panels get a makeover 3/13/13; we find out if Plexiglas is bulletproof Audible Physics, Acoustic Elegance, Alpine, Melodic Acoustic, Mosconi, Zapco
Quote:
Originally Posted by eviling
If you had a silver monte tou could i5 donated you montes bumper cover rear
But seriously, it is a great sounding sub. We tested it in 2 different cars with 4 different processors, and it never sounded bad. Convinced me to go IB as well. Good stuff.
The SBP15 will be available to order immediately at $289 individually. Current lead time as of 3/7/11 is about 4 weeks. SBP12's will be $249 each and have the same lead time. I expect to have these stocked for immediate shipment in small quantity once I am caught up on other orders here.
Great review Ally. I loved the sound of this sub in your car, and I concur with your praise of this great driver. It is also cool that I know most of the tracks you mentioned in this thread
Holy price hikes, Batman!!!....all the better reason to never sell my "ol school" IB12-8a
Without the price hike, Jon wouldnt be able to stay in business. Material costs have skyrocketed, but he never upped the price on the IB15's. He was pretty close to losing money on each one he sold.
Without the price hike, Jon wouldnt be able to stay in business. Material costs have skyrocketed, but he never upped the price on the IB15's. He was pretty close to losing money on each one he sold.
No doubt.
Like everything else in this "great" economy, you have to adjust or die.
Great review Ally. I loved the sound of this sub in your car, and I concur with your praise of this great driver. It is also cool that I know most of the tracks you mentioned in this thread
Thanks! I used your whole meet disc from last year to test it actually.
Quote:
Originally Posted by fish
Great in-depth review. I'm with ya on your description of AIC & "One". What low-pass point did you settle on.
Honestly, it has always varied. I've had it down to 50, 70, 80, 100 and 120 and they all sounded good. The one I used specifically for this test was 80hz. Don't know if that's the crossover I will keep it at in the future though. I'm thinking I need more time at each crossover point to see which it likes the best.
Quote:
Originally Posted by bassfromspace
Great review!
This is off topic, but how do you like the Quart amps?
The Q series are perfect for what I want/need. Only issue is occasional overheating, but I'm thinking of installing fans to combat that. I doubt I will change them in the distant future.
05 Monte Carlo - kick panels get a makeover 3/13/13; we find out if Plexiglas is bulletproof Audible Physics, Acoustic Elegance, Alpine, Melodic Acoustic, Mosconi, Zapco
Quote:
Originally Posted by eviling
If you had a silver monte tou could i5 donated you montes bumper cover rear
Bringing this back from the dead. Miller, what crossover point did you settle on and what slope(s) did you use for the best sub to midbass transition? - Thanks, I'm still breaking this baby in but so far I really like it!
The xover I use for competition is 45 @ 24db for the sub and highpassed the midbass at 63 @ 24.
05 Monte Carlo - kick panels get a makeover 3/13/13; we find out if Plexiglas is bulletproof Audible Physics, Acoustic Elegance, Alpine, Melodic Acoustic, Mosconi, Zapco
Quote:
Originally Posted by eviling
If you had a silver monte tou could i5 donated you montes bumper cover rear
The sub can handle anything you throw at it, from Brad Paisley’s I Wish You’d Stay, to the extreme lows of an organ, to fast-paced, hard-hitting dubstep and everything in between. The kick drum in Alice in Chains’ No Excuses will hit you so hard it is painful. The sub always moves with authority. In Metallica’s One, the double-bass towards the final half of the song are clear and extremely distinguishable – you can hear and feel each full, individual strike of the drum in perfect time. Limit to Your Love by James Blake begins abruptly with absurdly quick pulsating bass, which the SBP keeps up with perfectly. When the pulsating stops on a dime, so does the sub. This song is a magnificent test for any subwoofer, and the sub passes it with flying colors.
As is with any rear subwoofer, without time alignment, lower notes will of course reveal the location. With proper time alignment, this only occurs with drawn-out low frequencies and the great majority of the time you will forget the sub is even back there.
Thanks for the great review Ally. I did want to note that IB woofers are back in production now. The IB(xx)AU series will be up on the online store soon. Otherwise people can always email about them. I currently have about 20 motors built and ready to go as orders come in.
One of the biggest things I hear all the time is how quickly transients can be played with the woofers. Most any woofer can loudly play a long drawn out tone at high levels. It is when a woofer is asked to stop and start quickly that most have trouble. This is a function of the motor and the control that it has over the VC.
The main issue is flux modulation. As the VC is energized it becomes and electromagnet. As this electromagnet moves through the permanent magnetic field, it pushes it around, or "modulates" it. A good way to envision the effects is with a magnet near an old tv or computer monitor. As you move the magnet you can see the images move, change colors, etc. The VC has similar effect on the magnetic field in the motor of the woofer every time it moves back and forth. The more power input, the more significant effect which is why efficiency is important.
The VC is trying to push against the permanent magnetic field, but that field is moving. Imagine trying to push off of a solid wall vs pushing off of a wall with a sponge on it. The solid wall lets you push with full force instantly. The sponge first has to compress until you reach the solid wall, then when you push off the sponge will expand and change the rate at which you push off. The modulated flux field is very similar. It is very apparent when the flux field first has to settle before the VC itself completely stops moving. There is just no real control over the VC by the motor.
Klippel has a chart stating the various types of distortions and their causes. You can see that flux modulation has effects in both the sound pressure and current. It creates harmonic distortion not only in the audible sound, but even distorts the impedance curve and amount of current being applied to the woofer. What you end up with is a VC that isn't getting the right amount of current in a magnetic field that is unable to push the VC properly. The flux modulation is the most significant factor in distortion and "provides unique symptoms which are sufficient for the identification of the nonlinearity" meaning they are measurable and audible results. This is the primary factor in odd order harmonic distortions. The odd order are much more audible than even order.
To get rid of this issue we need to short all the eddy currents coming from the VC that move the magnetic field around. This will keep the flux field from moving and as a result get rid of the distortions. We do the same thing that is done in transformers to lower inductance. The full copper sleeve on the pole shorts any currents before they are able to move the flux field around. It results in a huge difference in harmonic distortion across the board. It also is very significant in how quickly transients can be handled. Listening to bass guitar solos where notes are quickly plucked and start/stop very fast is very telling. There is a short passage at the beginning of Duende by Black Light Syndrome I use to show this often. As the notes are played quickly with most woofers you will only hear a change of tone. With woofers with proper shorting rings, you can clearly hear each note start and stop. If you want to read a little more on what is done in the Lambda motors you can see the following page:
Thanks for the great review Ally. I did want to note that IB woofers are back in production now. The IB(xx)AU series will be up on the online store soon. Otherwise people can always email about them. I currently have about 20 motors built and ready to go as orders come in.
John
Would like to know what can you tell us about MMS. A strong cone with low MMS VS a strong cone with high MMS - big difference in testing and sound?
For all practical purposes, MMS is only a tool to get a given set of parameters that best fit the design. There is always talk about how MMS has a factor in how fast or slow the driver is. There is really no validity to that statement. I can take an IB15AU and measure the impulse response which shows how fast it starts and stops. I can then go and add mass to it, even a substantial amount and it will not affect the position of the impulse, only the magnitude of the pulse. Putting more power back in to get the pulse level equal to the original makes them essentially the same. It is really only an issue of level and not time delay starting or stopping.
There are several papers out there that verify it. This one is the original from Lambda Acoustics talking about how it is inductance, not mass that affects the "speed" of a woofer.
Often people don't really realize the amount of force the magnet can put on the coil. The magnet in a woofer has so much strength that any amount of moving mass that can never realistically be put in a woofer will have little affect on the amount of control the magnet exerts over it. You can get a small magnetic door lock that has enough strength to keep a 200lb man from even being able to even budge the door no matter how hard it is pushed or run into. Consider now the difference between 100-200grams on a woofer being controlled by the magnet vs the force that is controlled by the door magnet.
The one thing that is a factor though in MMS is where it comes from. Adding physical mass has no effect. Adding windings to the VC to create more mass will. It is not the mass that is creating the effects though. It is because the more windings in the VC, the stronger the electromagnet becomes, and the more it can move the permanent magnetic field. This gets back to the distortion issues of inductance again. This factor is the reason why people often think that high mass woofers sound "slower" or less controlled. It isn't because they are heavier, it is because they have more inductance.
But werewolf on here showed the math on why mms does matter with transients. Dan was not using a standard definition of transient.
Precisely the reason I asked about the main difference between low and high MMS. I've read Dan's theory about "woofer speed" and understand most of it. Just wanted to know if there was more to it...
I guess this part is the most important: "The one thing that is a factor though in MMS is where it comes from. Adding physical mass has no effect. Adding windings to the VC to create more mass will. It is not the mass that is creating the effects though. "
Kelvin
Lycan
Quote:
I'll repeat it for the miliionth time : All amps do NOT sound the same ... It's astonishing to me that nobody understands this
But werewolf on here showed the math on why mms does matter with transients. Dan was not using a standard definition of transient.
Dan's definition was incomplete, looking at impulse only.
When most people ask about the effect of Mms on transient response they are usually asking if or implying that it makes the driver "slower" or "faster", which is (IMO) why John (Dan, et al) pointed that the impulse response isn't affect by mass.
What werewolf was saying is that Mms affects Q, Fs, etc which affects the damping of the system and transient response in that regard (overshoot, ringing, etc), but not the impulse. Which is what John touched on with the very first sentence of his post.....Mms affects the parameters of the driver (and by extension transient response), but not impulse response.
No doubt.
Like everything else in this "great" economy, you have to adjust or die.
Agreed. John offers a great, very well made (in the US) product at a very competitive (and reasonable) price. You can't ask for much more than that.
If these were made by a "big" name like a JL Audio, they'd be double the price. And that's not saying that JL would be making double on the same product...they just have much more overhead and cost. By keeping a smaller, stream-lined operation, it appears John is able to offer a superior product at a lower pricepoint to us. The only downside to this model (for us)is low supply since it's a small shop and (for John) likely higher material costs to due less economy of scale benefit. Personally, I like the lower output and attention to detail. That's worth a 4-6 week waiting period in my book.
Thanks Ally for the great review. I'd like to try one of these in my install.
I have yet to install mine, so I can't make a comment of how it sounds. I do like the fact that it has a label on it with my name. It was lovingly made, just for me. You can't say that very often. Thanks John
One thing I would do differently (maybe) is use only one instead of two. The trunk of my Acura TL (12.5 cubes) is seemingly not large enough for the pair, causing me to have to cut 50hz quite a bit and boost the low end. Removing all carpet (adding trunk volume) has made them quick, tight, all of the above again and I'm currently using no EQ on them. Obviously I can't go without trunk carpet forever.
They do so well in the upper frequencies that even with 9" midbasses I always want to let the 15s play up higher than normal.
'84 GN 10.60@ 127mph. Infinity 3.5 coaxials and a cheap Sony HU.
Acoustic Elegance SBP15-4 review
Press here
Thanks John
Linear Mode
