Check out Sonido SFR200A. Outstanding drivers! Use them with two alphas in OB, exceptional sound 🙂
Thank you. I thought I made my skill set and experience pretty clear. Maybe not clear enough? Oh well, all I can do is try to learn.
cubdog
If you want to keep it simple follow the OB article here http://www.quarter-wave.com/Project09/Project09.html . There is a new 4" full range by Faital Pro that looks made for OB use with a QTS of .84, 91dB very flat frequency response & impedance graphs, low Le and copper cap for lower distortion. I think at 91dB you don't need any attenuation to match the Alpha either. http://www.parts-express.com/faitalpro-4fe35-4-professional-full-range-woofer-8-ohm--294-1124
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I've looked at that build but I'm pretty set on going with dual Alphas. My plan is to use an active crossover.
BTW, can someone explain to me just what the Qts ratings mean? I have know idea what significance they have.
cubdog
Qts is the total "Q" - a measure of how much damping the driver has. High Qts is low damping and response will be 'peaky'. For open baffle (OB) you want a high Qts driver as it can have a natural lower frequency for bass extension without the help of ported or horn loaded enclosures. High Qts is typically something above about 0.6, close to 1 or more is ideal for open baffle. Drivers with low Qts (like 0.3 or below) have very powerful motors and high damping and will not achieve bass without a properly designed vented enclosure. If you look at the Qts rating on the Alpha 15A you will see that it is has a Qts of 1.23, note how small the magnet (motor) assembly is vs the size of the driver. The Alpha 15A is ideally suited for OB. Another use for high Qts drivers is a sealed cabinet - with the correct sealed volume, a high Qts driver will reach about the fs stated. A low Qts driver in a sealed cabinet will not reach its fs without significant EQ'ing. Hope that helps. You should read up more about Thiele Small parameters if you plan on doing more diy speaker building.
Thank you xrk. One more question. Is there a method of matching the FR driver to the woofer using these numbers. I mean, of course, as a starting point just so I can eliminate obvious mismatches.
cubdog
cubdog
If you are going active thats even better.Thats how I run mine. It allows you to eq the mid/high frequency driver to tame the tendancy to have rising hi freq response.No need to get all complicated with this build. Pick a driver thats within your budget and build it. there are lots to choose from and any one of them will give you a very nice sounding seystem. You can always get more complex on your next build. if your set on an 8" you can look at the daytons, the AN, fe206,visatons, sonido or the more exotics if your budget allows.Some guys go even bigger with drivers like the 12lta etc.
I was on the very same path not long ago and was seriously looking at the 8" dayton. It looks like a very good choice for an active OB and is known for having very good high freq extension.
I was on the very same path not long ago and was seriously looking at the 8" dayton. It looks like a very good choice for an active OB and is known for having very good high freq extension.
>>> if your set on an 8" you can look at the daytons, the AN, fe206,visatons, sonido or the more exotics if your budget allows.Some guys go even bigger with drivers like the 12lta etc.
I have the 1808 and the larger 12lta. I love and enjoy BOTH. I have several drivers I love by Fostex and TB of various sizes. It's easy to love these drivers because they are easy to work with and sound great. I would argue they ALL sound better than speakers using crossovers but that's for another thread.
All day yesterday I listened to the TB 1808 (sealed cabinet) on top of an H-frame using one Alpha 15 powered by a 150 watt sub amp (the Alpha 15 needs power on an open baffle). The combination is fantastic. IMO the Alpha 15 on OB - with the right powered sub - is a great choice for bass.
An open baffle 12lta (with helper tweeter) on top of the same H-frame is also fantastic but sounds very different. The sound is larger and more easily fills the room (which is large). But it's more aggressive sounding and less detailed overall.
Thee other full range drivers listed (among others) will all have a sonic signature and part of the process is finding the brands you enjoy most by purchasing a few different ones to listen to. The debate over which is better is largely subjective since they are all built to similar price points with similar overall performance goals. Ultimately, it's that fullrange sound we're after... that effortless, detailed sound... that natural midrange that floats in space... that ghostly imaging... the sound you get without a crossover in the middle.
I have the 1808 and the larger 12lta. I love and enjoy BOTH. I have several drivers I love by Fostex and TB of various sizes. It's easy to love these drivers because they are easy to work with and sound great. I would argue they ALL sound better than speakers using crossovers but that's for another thread.
All day yesterday I listened to the TB 1808 (sealed cabinet) on top of an H-frame using one Alpha 15 powered by a 150 watt sub amp (the Alpha 15 needs power on an open baffle). The combination is fantastic. IMO the Alpha 15 on OB - with the right powered sub - is a great choice for bass.
An open baffle 12lta (with helper tweeter) on top of the same H-frame is also fantastic but sounds very different. The sound is larger and more easily fills the room (which is large). But it's more aggressive sounding and less detailed overall.
Thee other full range drivers listed (among others) will all have a sonic signature and part of the process is finding the brands you enjoy most by purchasing a few different ones to listen to. The debate over which is better is largely subjective since they are all built to similar price points with similar overall performance goals. Ultimately, it's that fullrange sound we're after... that effortless, detailed sound... that natural midrange that floats in space... that ghostly imaging... the sound you get without a crossover in the middle.
For matching the full range top to the bottom woofer, traditionally you look at the stated efficiency numbers (for example, 85 dB, 2.83 volts at 1 meter) and pick a woofer that is at least 10 dB more efficient than the top. This is assuming you are driving them from one amp and using a passive crossover. With active crossover and bi-amping, it is less critical as you can dial in the amplitude needed to balance the top and bottom. The reason the bottom needs to be more efficient is to balance with the top driver as the bass from an OB woofer is very inefficient (it falls off at -6dB/oct below the OB frequency determined by baffle width - typically in the ~300 Hz range for practical baffle widths).
So if you have the Alphas 15A at 97dB efficiency, then your fullrange top should be no more than about 87 dB efficiency. If you are running two Alpha 15A in parallel for 4 ohm load that is 103 dB efficiency at 2.83 volts so the full range should be no more than 93dB efficient at 2.83 volts. This would indicate that you can use something like the Faital Pro 4FE35 which is 91 dB efficient. There are also Fostex's out there that will have this kind of sensitivity but they are more expensive, have lower xmax, a some don't like their "shout" in the vocal band.
A very good resource for learning about OB speaker (dipole speakers) is Sigfreid Linkwitz's website: PHOENIX - Open Baffle Loudspeaker Look at the Orion speaker in particular.
And the Dipole Woofer: Dipole Woofer
Thanks again guys. I'm planning to drive the Alphas with my Bel Canto mono blocks. They are 150 wpc 8 ohm, 300 wpc 4 ohm. I haven't yet decided what to use for the FR but have a few options available.
I'm getting anxious to get started but I'm trying not to get ahead of myself and do something stupid. That I am very capable of.
cubdog
I'm getting anxious to get started but I'm trying not to get ahead of myself and do something stupid. That I am very capable of.
cubdog
You should have very satisfying bass with those amps. Have you chosen a DSP? .I run a 2 watt triode amp for my top end. Because of that i add a 6db boost to the bass drivers so I can maitain higher overall efficiency. It takes some playing around but eventually you can get it to blend seamlesly with the other driver and the room.If possible use some type of rear brace on the 15a's to couple them better to the font baffle. I found it makes a noticable dif to the quality of bass. The 15a's dont have great magnets and it helps to tighten up the bass a bit.
>>> Thanks again guys. I'm planning to drive the Alphas with my Bel Canto mono blocks. They are 150 wpc 8 ohm, 300 wpc 4 ohm.
Your good to go with those amps and won't have to worry about efficiency issues that xrk has pointed out since you will be using dedicated amps. Only if you are using one amp must you heed xrk's advice.
What will you use to drive the full range driver?
Your good to go with those amps and won't have to worry about efficiency issues that xrk has pointed out since you will be using dedicated amps. Only if you are using one amp must you heed xrk's advice.
What will you use to drive the full range driver?
Well, that is still the issue. So many driver choices but unfortunately I haven't heard any of them. As I initially stated I was set to go with an 8 in. FR but then there were some here who advised against that. I guess I'm still leaning in that direction only because I know a couple of guys who went that route and are quite pleased with their results.
cubdog
OK, but the way you're presenting it will require way more efficiency than will ever be needed for BSC, so very misleading to a neophyte.
How much efficiency is required to handle the desired ~ flat in room LF gain BW is a completely different subject with a number of variables involved as you noted, so just picking some high number isn't any real help either, especially since a number of extra woofers plus some form of EQ may be required.
GM
No matter what you decide there will always be those who advise against it. Everyone has their preferences.I doubt very much that you would find a lot to complain about if you use an 8" driver. There are always tradeoffs.
What are you after? . Some like ulta detailed systems. Some just want smooth fr. Some prefer a really big sounding system while others prefer a bit of vintage tone.
Your preference could help narrow down driver choice.
I listen primarily to Jazz. Probably 85% of the time. Moderate volume, not a bass guy except to say I hate any bass distortion. While I don't listen at extreme volumes I want my speakers to sound like I can turn them up as loud as I want and hear no strain on them. Midrange is the most important to me. That's about it.
cubdog
That makes it fairly easy. Most if not all of the moden jazz is very well produced. So again any of the mentioned drivers will produce good results.You might want to avoid the fostex simply because they usually require some work to the divers to realize their full potential.They are capable of very good sound but being a first go at this sort of project it might be more trouble than you want.The betsys are known for a very pleasant and easy to listen to sound. They may not be as detailed as some others but many people really like them.They might be a good choice to start. Not very expensive and easy to work with. If you find down the road you want more detail its very easy to upgrade.
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