I'm about to start a near-field monitor project for my work desk using speaker units from SB acoustics.
The thing is that I don't know much about their units and I would like some recommendations for my project regarding choice of bas/midrange and tweeter along with box topology.
I would like to build an active 2.1 system with some small near-field desk monitors and a 8" sub using DSP to handle my crossovers. My initial idea was to use their Micro C kit as inspiration, but I'm not sure if I should keep it as a reflex box when I have the sub, or build it as a closed box midrange speaker instead.
I find it kind of hard to spot the main differences in sound from some of their units that seems to be similar, except for the choice of membrane materials, what can I expect to be different when choosing a ceramic over a paper or plast membrane?
The thing is that I don't know much about their units and I would like some recommendations for my project regarding choice of bas/midrange and tweeter along with box topology.
I would like to build an active 2.1 system with some small near-field desk monitors and a 8" sub using DSP to handle my crossovers. My initial idea was to use their Micro C kit as inspiration, but I'm not sure if I should keep it as a reflex box when I have the sub, or build it as a closed box midrange speaker instead.
I find it kind of hard to spot the main differences in sound from some of their units that seems to be similar, except for the choice of membrane materials, what can I expect to be different when choosing a ceramic over a paper or plast membrane?
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The Micro C tweeter (i.e. the SB19ST-C000-4) is most certainly still available. It is a stock model and we have absolutely no plans to discontinue this driver.
My bad, I have corrected my post.
Still I would like some recomondations regarding open or closed box for the desk monitors, and choice of membrane materials for the bas/midrange?
Still I would like some recomondations regarding open or closed box for the desk monitors, and choice of membrane materials for the bas/midrange?
Don't ignore the SB12PAC version as it's a very good driver but I haven't heard the SB12CAC.
A good option is Jeff Bagby's Soprano.
Various loudspeaker design suggestions
A good option is Jeff Bagby's Soprano.
Various loudspeaker design suggestions
For a (true) monitor, I would pick one of the hard cone drivers, as I find they reproduce instruments a little more naturally (e.g. harmonics and decay) - voices also have slightly better definition, I think. For a small near-field monitor, I would probably go with the SB15CAC30-4/SB15NBAC30-4 (needs 8 liters vented) or the SB12CACS25-4 if it needs to be smaller.
Thanks for your suggestions so far. Would it be any advantage to build a closed box design, since I will have a sub to handle the bass? or would i still need the ported box to close the gap between the midrange and sub?
The sub I'm thinking of using is the SB23MFCL45-8.
The sub I'm thinking of using is the SB23MFCL45-8.
The SB12CACS can be considered as a refined version of the SB12PAC. Essentially, it is the same driver - difference is that the SB12CACS uses a cast aluminum frame and it has a shorting ring in the motor system (which is otherwise identical). The surface treatment on the cone is a different process. The SB12PAC cone (as well as the NBAC cone) is anodized, whereas the CAC cones are treated with a plasma process that penetrates slightly deeper into the material (i.e. it turns a little more of the aluminium into a ceramic material) - but it is the same basic cone that is used.
I'm not much into subwoofers/satellites but the basic rule is to cross lower than possible to lessen the artifact of a differently located source between bass and satellite.The satellite itself is a big IF ...! The desktop position is literally the worst, having reflecting surfaces in the nearby. The speaker box should stay suspended with rubberbands, at least.
Why the 4Ω models? The amplifier distorts more on lower loads, though it gives more power.
So this allows the sub to reproduce the first octave and the satellite is freed from those bad, low frequencies
I would definitely use a vented enclosure (you can always plug the port). Even if you cross it over higher than the tuning frequency, it will still sound more open and dynamic than a sealed enclosure the same size, in my experience. You can certainly get away with using a sealed box and still make it sound open - but it requires a larger box. When using a (high-pass filtered) midrange driver with a sealed enclosure, don't think in terms of bass alignment when you calculate the box volume (and for sure don't be tempted to use an even smaller volume just because the high-pass filter defines the lower roll-off anyway) - make the sealed MIDRANGE enclosure a big as you can to ensure dynamics. If you go with the vented enclosure, calculate the box volume and tuning frequency as you normally would with a (mid)woofer .
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I see, I have tried to play around with WinISD and the 12CACS25-8, to compare it to the Micro C. It just seems strange to me that WinISD suggest a volume of 4.8L while the Micro C is only about 2.8L.
Another way to go would be to scrap the sub and go for a larger 2-way construction. But still i would like to keep the size down in order to preserve some desk space for work.
Is there any opinions regarding the tweeter? I have thought of maybe using the SB26ADC-C000-4 since it seems to be popular in Troels Gravesens 2 way constructions.
But also I'm curious to know why its the 4 ohm versions that is refered to, since the amplifiers usually perform better at 8 ohm. Although amplifier power is not a limitation for this project.
Another way to go would be to scrap the sub and go for a larger 2-way construction. But still i would like to keep the size down in order to preserve some desk space for work.
Is there any opinions regarding the tweeter? I have thought of maybe using the SB26ADC-C000-4 since it seems to be popular in Troels Gravesens 2 way constructions.
But also I'm curious to know why its the 4 ohm versions that is refered to, since the amplifiers usually perform better at 8 ohm. Although amplifier power is not a limitation for this project.
Simming program's default vented alignment is a T/S max flat alignment, but look at the responses; it's vented, yet the lower impedance peak is off the graph it's tuned so low relative to cab peaking, hence it can be sized more like sealed, yet yields a bit more low end before a sealed like roll off, hence a bit more power handling down low.
All things considered, an excellent alignment for near-field and/or when a sub system is employed.
GM
You are looking at the SB12CACS25-8. The Micro C uses the SB12CACS25-4, which has a lower Qts.
2.6 liters (effective acoustic volume) and port tuned to about 59 Hz is in every way optimum for the SB12CACS25-4 (perfect smooth roll-off and excellent transient behavior). This is assuming a series resistance of 0.4 ohm in the passive network and typical box losses.
Vented is the way to go and good reasons have been mentioned above. Before thinking of a sub, see what the bass is like on the speakers as it may be enough for near field use. I prefer to have a speaker with an F3 between 60-75Hz for this use.
Have a read of the article on the Soprano as it gives a good look into design choices. Especially read the section on bass tuning as Jeff comments and having a hump before roll off as it balances the sonics in a small speaker and I use this method.
The SB26ADC is a great tweeter and use mine with a SB17NAC35-8.... excellent combination. These metal SB Acoustics drivers still surprise me.
Have a read of the article on the Soprano as it gives a good look into design choices. Especially read the section on bass tuning as Jeff comments and having a hump before roll off as it balances the sonics in a small speaker and I use this method.
The SB26ADC is a great tweeter and use mine with a SB17NAC35-8.... excellent combination. These metal SB Acoustics drivers still surprise me.
I was just playing around with some simulations for the sub I intend to pair the satellites with.
It seems that the SB23MFCL45-4 would require the smallest box in a closed box application. What I need here is a sub or bass extension that will work for electronic music and not for movies. My target is to get bass extension down to about 35-40Hz so I dont know if something like the CACS woofers would be a better choice?
It seems that the SB23MFCL45-4 would require the smallest box in a closed box application. What I need here is a sub or bass extension that will work for electronic music and not for movies. My target is to get bass extension down to about 35-40Hz so I dont know if something like the CACS woofers would be a better choice?
For music I prefer to go with standard woofers and not subwoofers drivers.
FWIW, I did try the SB23MFCL45-4 and had issues with the partnering plate amp. Nothing wrong with the driver as far as I can tell but the 200W amp either didn't have enough gain or current for this driver. I've used plenty of these plate amps over the years and tested this one with a 830452 and worked fine. Others had a similar problem which was solved by increasing input gain. Just choose the partnering amp wisely.
FWIW, I did try the SB23MFCL45-4 and had issues with the partnering plate amp. Nothing wrong with the driver as far as I can tell but the 200W amp either didn't have enough gain or current for this driver. I've used plenty of these plate amps over the years and tested this one with a 830452 and worked fine. Others had a similar problem which was solved by increasing input gain. Just choose the partnering amp wisely.
I don't have any experience with SB Acoustic brand but if I where building a set of 2 way near field monitors I would use an 8" poly prop woofer (a 6 1/2" will work too) and a metal dome tweeter titanium or aluminum/magnesium alloy in a sealed and heavily damped box. I would also off set the tweeter so you can widen your sound stage a little by having the tweeters on the outside. The speakers should not be placed on the desktop though and are ideally placed on an open shelf (no sides-no shelf above- with the speakers siting on the front most edge) with no wall directly behind it. Speaker stands work nicely too. If you use a sub use two subs left and right. With reference monitors, at least for mixing, you really shouldn't use subs unless you are mixing rap and even then.
What do you plan to use them for?
Important that you match the drivers sensitivity, power handling and impedance, a 6 ohm nominal impedance would be ideal.
Do you plan on going active as in plate amps mounted to the rear of the speaker with separate amp sections for the woofer and tweeter possibly with active cross overs or external amps with DSP bi-amped? Or are you planing to use passive cross overs?
What do you plan to use them for?
Important that you match the drivers sensitivity, power handling and impedance, a 6 ohm nominal impedance would be ideal.
Do you plan on going active as in plate amps mounted to the rear of the speaker with separate amp sections for the woofer and tweeter possibly with active cross overs or external amps with DSP bi-amped? Or are you planing to use passive cross overs?
I think a 8" monitor is far beyond the size of what I'm looking for.
I am however considering going for the SB15CAC30-4 for a two way stand alone setup without the sub. It seems like I would be able to fit them in a 9l box tuned to around 35-40Hz.
They are just going to be used for listening for music while I work, but since i will used them for many hours every day then I would like the best possible sound.
I'm not sure why its important to match the drivers sensitivity, power handling and impedance or the 6 ohms when they will be used in a active setup with DSP and an amp channel for each driver.
I am however considering going for the SB15CAC30-4 for a two way stand alone setup without the sub. It seems like I would be able to fit them in a 9l box tuned to around 35-40Hz.
They are just going to be used for listening for music while I work, but since i will used them for many hours every day then I would like the best possible sound.
I'm not sure why its important to match the drivers sensitivity, power handling and impedance or the 6 ohms when they will be used in a active setup with DSP and an amp channel for each driver.
Ok so you are more looking at HIFI desk top speakers the near field monitors then. In that case an 8" woofer won't be necessary and I'd probably use a ported box with a sub woofer.
Near field monitors are typically used in recording and mixing and have different requirements then HiFi speakers. They need to be as flat as you can get them to a point that they may even sound a bit subdued. You typically don't use DSP or make room adjustments or EQ them as they are near field and you will be hearing them mostly directly so your mix won't have the room imprinted on it.
In other words they are good for music production but not necessarily what you would want to listen to music through.
The importance with matching sensitivities has more to do with the drivers being matched through the entire range of volume. Meaning do the drivers come up to volume at the same rate? Do they sound coherent at full volume, mid volume and low volume? This is important unless you only listen to music turned up to 11.
6 ohms is good for a few reasons like getting more out of your amps while still having the lower distortion of the 8 ohm drivers. But 4 ohm and 8 ohm can be used as well.
Near field monitors are typically used in recording and mixing and have different requirements then HiFi speakers. They need to be as flat as you can get them to a point that they may even sound a bit subdued. You typically don't use DSP or make room adjustments or EQ them as they are near field and you will be hearing them mostly directly so your mix won't have the room imprinted on it.
In other words they are good for music production but not necessarily what you would want to listen to music through.
The importance with matching sensitivities has more to do with the drivers being matched through the entire range of volume. Meaning do the drivers come up to volume at the same rate? Do they sound coherent at full volume, mid volume and low volume? This is important unless you only listen to music turned up to 11.
6 ohms is good for a few reasons like getting more out of your amps while still having the lower distortion of the 8 ohm drivers. But 4 ohm and 8 ohm can be used as well.
The DSP will handle crossovers, time alignment, driver gain, signal limiting, wake on music and much more within the speaker itself. So it's not there to do room corrections. This is something all modern manufactures of active speakers does.
The sound I'm looking for is the neutral sound of a monitor. Also why my current HiFi setup is from Dynaudio.
The issue with some normal bookshelf HiFi speakers is that they are often meant to be listened to from a distance and therefore can sound too sharp or bright when you get up close like I will be.
The sound I'm looking for is the neutral sound of a monitor. Also why my current HiFi setup is from Dynaudio.
The issue with some normal bookshelf HiFi speakers is that they are often meant to be listened to from a distance and therefore can sound too sharp or bright when you get up close like I will be.