Re: Re: Re: How Much Bass Is Enough???
It may be that the placement of the subwoofers is as important as the approach. Of course we all know that in real rooms you often can't place speakers were you'd like but must make due with acceptable alternatives. Trying to place several subs would in non dedicated rooms be difficult.
BHTX said:
It may be that the placement of the subwoofers is as important as the approach. Of course we all know that in real rooms you often can't place speakers were you'd like but must make due with acceptable alternatives. Trying to place several subs would in non dedicated rooms be difficult.
Moondog55 said:
I wonder how the IB method works for music. The hard core HT people claim this is the best for sound quality and bass dynamics. In a music listening room not having to place speaker cabinets would be nice. But of course you do need to have an adjacent attic space or crawl space or garage. Also, my guess is that it would need to be kept below 50Hz for music.
Here is my idea for some mains that are super dynamic and have a lot in the low bass.
I have really been intrigued by the Elsinore speakers which use four identical mid/bass drivers in a special crossover configuration that allows for easy impedance to drive, high sensitivity, very dynamic and great bass response. Also commercial speakers which are supposed to be good at large scale orchestral stuff like the Wilson Maxx and Alexandria are a little similar but different crossover topology.
This is just a concept work up using 5.25 and 6.5 upper mid/bass and 8 and 10 inch lower bass drivers. My speakers will be used near the wall so I only want 3 db of baffle step and will have the lower drivers be 3 db more efficient so the lower crossover will be at the baffle step.
But if you wanted more baffle step you could have the upper drivers run all the way down so that at the lowest frequencies you have all drivers working at still a nice easy impedance using a series/parallel hookup topology.
The lower footprint of this design is 15 inches wide and 24 inches deep.
I think it could be scaled up so as to use 6.5, 8, 12, 15 inch drivers in a little bigger cabinet. With all of these drivers running at the lower frequencies you can move a lot of air and at higher frequencies only the upper drivers are working above the BS frequency.
Something like this might be able to approximate what you are trying to get at without using subwoofers. By using modestly priced higher efficiency drivers. My idea is for the upper drivers to be open back. For the upper woofer to be aperiodic and for the lower to be reflex loaded. One woofer gives me extension and one gives better pitch definition.
I have really been intrigued by the Elsinore speakers which use four identical mid/bass drivers in a special crossover configuration that allows for easy impedance to drive, high sensitivity, very dynamic and great bass response. Also commercial speakers which are supposed to be good at large scale orchestral stuff like the Wilson Maxx and Alexandria are a little similar but different crossover topology.
This is just a concept work up using 5.25 and 6.5 upper mid/bass and 8 and 10 inch lower bass drivers. My speakers will be used near the wall so I only want 3 db of baffle step and will have the lower drivers be 3 db more efficient so the lower crossover will be at the baffle step.
But if you wanted more baffle step you could have the upper drivers run all the way down so that at the lowest frequencies you have all drivers working at still a nice easy impedance using a series/parallel hookup topology.
The lower footprint of this design is 15 inches wide and 24 inches deep.
I think it could be scaled up so as to use 6.5, 8, 12, 15 inch drivers in a little bigger cabinet. With all of these drivers running at the lower frequencies you can move a lot of air and at higher frequencies only the upper drivers are working above the BS frequency.
Something like this might be able to approximate what you are trying to get at without using subwoofers. By using modestly priced higher efficiency drivers. My idea is for the upper drivers to be open back. For the upper woofer to be aperiodic and for the lower to be reflex loaded. One woofer gives me extension and one gives better pitch definition.
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Moondog55 said:
Greets!
Well, what can I say, I can only respond to what's posted, I suck as a mind reader as do 'L' shaped rooms if you can't use its 'V' as the focal point.
I don't have either the P11 or 13's details, but I'm sure they are going to be small/inefficient enough that 120 dB is going to be somewhere down the street from the symphony hall and if they're like some other Vifa's I've auditioned, they will audibly distort at fairly low low power, so with a wide dynamic range CD about all you can do is have enough power on tap to keep from clipping the amp and turn them up until they start sounding stressed and back them down a notch or two since these types of symphonies tend to have incredible energy up to 500 Hz (though still clipped).
Really, you need a wide BW mid-bass system to cover the ~50-500 Hz decade to take most of the heart pounding dynamic load off these over-sized tweeters and you can't beat prosound drivers in this BW, it's what they're designed for. Now with a decent horn tweeter you can do a relatively stress free MTM.
WRT subs, you ideally need a 0.5 Qtc sealed alignment if transient perfect ~8 Hz horns aren't an option since some CDs have energy this low and you want to preserve the attack/decay all the way down. Since we're dramatically scaling the system back to meet all the constraints though, you can get by using whatever local drivers with a low Fs, Vas, Le is available to make several relatively small subs capable of keeping up with the mid-bass system. Indeed, depending on the drivers available locally you could get by as I do with dual low Qts 15"/channel in large EBS alignments tuned to 14-16 Hz which have as good or better a transient response as a 0.5 Qtc sealed alignment above ~30 Hz and skip a sub system altogether since most of the energy will be concentrated in the ~30-300 Hz decade.
GM
Then you potentially runinto thermal compression issues. A balance is needed.dangus said:
That would depend upon drivers and implementation, but I see no reason why some IB's could not be crossed higher with suitable design and drivers. I doubt >100Hz would be much chop unless handled well.Hezz said:
It's funny but until I joined this forum and really started learning I would never have considered PRO drivers or midranges bigger than 5 inches.
Steep learning curve, but I'm getting there.
Hezz! your design looks like something the wife could live with.
GM, I think you do pretty well, but really the room sucks, I think I am really designing in my head the system we want and need for the next house.
has anyone got any thoughts on Zaphs comments that low X-max drivers sound better?? and does this apply to bass drivers as well as mids? Just as an thought experiment what would a large number of cheaper drivers ( good sounding but low power handling ) be like compared to a pair of drivers able to handle much more power??
How do you compare the sound of a group of Double-Bass whose radiating area is quite high but moving a very small distance, with its reproducer { the driver } moving a great distance in comparison??
I know I'll have to build it and find out, but is there an upper limit on the number of bass drivers ??
In other words how many might be too many??
Thanx for all the replys so far, this next pair may wind up much bigger.
Regards Ted
Steep learning curve, but I'm getting there.
Hezz! your design looks like something the wife could live with.
GM, I think you do pretty well, but really the room sucks, I think I am really designing in my head the system we want and need for the next house.
has anyone got any thoughts on Zaphs comments that low X-max drivers sound better?? and does this apply to bass drivers as well as mids? Just as an thought experiment what would a large number of cheaper drivers ( good sounding but low power handling ) be like compared to a pair of drivers able to handle much more power??
How do you compare the sound of a group of Double-Bass whose radiating area is quite high but moving a very small distance, with its reproducer { the driver } moving a great distance in comparison??
I know I'll have to build it and find out, but is there an upper limit on the number of bass drivers ??
In other words how many might be too many??
Thanx for all the replys so far, this next pair may wind up much bigger.
Regards Ted
Sounds like you're at the very start of an interesting long journey that lies ahead of you. A lot of reading, even more reading, a lot of time, perhaps a bit of experimenting, more reading, it never ends..
Anyway, in short answer to one of your questions.. cone movement = distortion. Generally, the less a woofer's diaphragm is required to travel to produce a certain SPL, the better. This, of course, leads to higher efficiency, which leads to larger space requirements. It's all trade-offs and compromises. Everything from the loudspeaker design as a whole, down to the drivers themselves (and the amplifier(s), the room, etc), is nothing but a matter of specific trade-offs and compromises to reach a certain specific goal or criteria for a design or system.
As for multiple drivers, there are line-arrays that use dozens of them. Of course, they have their own compromises versus other types of designs, just like everything else.
As for multiple low frequency drivers, I'm assuming you're speaking of subwoofers? If that's the case, it really just depends.. After you've gone way past your max SPL target, yeah sure.. you can go overboard with it, at which point you'll just be throwing money (and space, and electricity, etc). At this point, with loudspeakers in general, rather than thinking about how many drivers are used, think about the best way to use 1 of them.
My suggestion to you at this point (and perhaps always), is to focus on simplicity. You'll never absolutely have to utilize a ton of loudspeaker drivers to reach any goal or criteria in your own home (unless you actually want to build a line array, but no one really wants to BUILD one of those. Or, if you've come up with a very promising design using multiple drivers for a very good reason). For example, 40Hz to 20KHz can EASILY be reproduced at levels of well over 120dB with only TWO drivers in a relatively compact enclosure (or at least 'compact' by my standards, anyway), and can actually sound very good (at much lower levels, of course).
Anyway, in short answer to one of your questions.. cone movement = distortion. Generally, the less a woofer's diaphragm is required to travel to produce a certain SPL, the better. This, of course, leads to higher efficiency, which leads to larger space requirements. It's all trade-offs and compromises. Everything from the loudspeaker design as a whole, down to the drivers themselves (and the amplifier(s), the room, etc), is nothing but a matter of specific trade-offs and compromises to reach a certain specific goal or criteria for a design or system.
As for multiple drivers, there are line-arrays that use dozens of them. Of course, they have their own compromises versus other types of designs, just like everything else.
As for multiple low frequency drivers, I'm assuming you're speaking of subwoofers? If that's the case, it really just depends.. After you've gone way past your max SPL target, yeah sure.. you can go overboard with it, at which point you'll just be throwing money (and space, and electricity, etc). At this point, with loudspeakers in general, rather than thinking about how many drivers are used, think about the best way to use 1 of them.
My suggestion to you at this point (and perhaps always), is to focus on simplicity. You'll never absolutely have to utilize a ton of loudspeaker drivers to reach any goal or criteria in your own home (unless you actually want to build a line array, but no one really wants to BUILD one of those. Or, if you've come up with a very promising design using multiple drivers for a very good reason). For example, 40Hz to 20KHz can EASILY be reproduced at levels of well over 120dB with only TWO drivers in a relatively compact enclosure (or at least 'compact' by my standards, anyway), and can actually sound very good (at much lower levels, of course).
Actually, I see now that you've been here for a while. I've never been a morning person...
Good point, just reading thru one of Raymond Briggs books on speaker design I note that he has said that same thing, and earl Wharfdales were simple, 15 inch woofer 10 inch midrange, no box just a big baffle.
BHTX In this context I meant Woofers and subwoofers, those drivers that handle the frequencies up to the cross to the mids at whatever point that is ( 180 to 300 Hz)
I am going to read more, experiment more and think less until I've got to get a few more projects finished, then I am going to compare designs side by side.
I may keep the next boxes for a while instead of being not completely happy and giving them away to family.
BHTX In this context I meant Woofers and subwoofers, those drivers that handle the frequencies up to the cross to the mids at whatever point that is ( 180 to 300 Hz)
I am going to read more, experiment more and think less until I've got to get a few more projects finished, then I am going to compare designs side by side.
I may keep the next boxes for a while instead of being not completely happy and giving them away to family.
How much bass is enough?
More. More bass is enough.
Really, for realistic bass performance, which has a lot of built in problems, you need to go as big as you realistically can, to drive distortion levels down and power handling/output/dynamics up. How much you REALLY need is a question of budget, space, time, effort, understanding of the significant other.....
More. More bass is enough.
Really, for realistic bass performance, which has a lot of built in problems, you need to go as big as you realistically can, to drive distortion levels down and power handling/output/dynamics up. How much you REALLY need is a question of budget, space, time, effort, understanding of the significant other.....
Hello Moondog
Depends on your listening habits. Scale it up over time. I would start with at least a pair of subs and run them as dedicated Left and Right. For HT I would think a dedicated LFE sub would fill things out but you could easilly add that latter. That's the set-up I use and it seems to get the job done. I have a pair of 14" drivers as my dedicated L/R subs and a 15" for LFE. One thing nice about the pair is with mutual coupling you can get +6db of gain even before room gain. That is a significant as long as you can keep them close enough which usually will work out if they are close to your mains.
Rob
Depends on your listening habits. Scale it up over time. I would start with at least a pair of subs and run them as dedicated Left and Right. For HT I would think a dedicated LFE sub would fill things out but you could easilly add that latter. That's the set-up I use and it seems to get the job done. I have a pair of 14" drivers as my dedicated L/R subs and a 15" for LFE. One thing nice about the pair is with mutual coupling you can get +6db of gain even before room gain. That is a significant as long as you can keep them close enough which usually will work out if they are close to your mains.
Rob
I really think that good dynamic full range sound can be accomplished for reasonable amounts of money. At the most basic level it involves some good sounding mains that are dynamic, efficient and good sounding and can do very realistic bass down to say 35- 40 Hz.
Then the only thing further needed is a single big cabinet subwoofer. I'm talking rather big though. Minimum of 4 cubic feet. Better would be a 10-20 cubic foot cabinet. And very well made(braced). Funny thing is that we used to use big console stereo systems that were this big. We never complained back then. Of course everything was included. No additional speakers. But the subwoofer cabinet can double as a table and piece of furniture. Anything this big would likely have to double as somekind of other useful device for the significant other to accept it.
My guess is that a 15 or 18 inch driver in a critical Q sealed cabinet would be unbeatable for sound quality. This would not be a modern subwoofer driver which typically have low sensitivity and high xmax but a classic type driver built to modern standards. So the driver cost is not that expensive.
Then the only thing further needed is a single big cabinet subwoofer. I'm talking rather big though. Minimum of 4 cubic feet. Better would be a 10-20 cubic foot cabinet. And very well made(braced). Funny thing is that we used to use big console stereo systems that were this big. We never complained back then. Of course everything was included. No additional speakers. But the subwoofer cabinet can double as a table and piece of furniture. Anything this big would likely have to double as somekind of other useful device for the significant other to accept it.
My guess is that a 15 or 18 inch driver in a critical Q sealed cabinet would be unbeatable for sound quality. This would not be a modern subwoofer driver which typically have low sensitivity and high xmax but a classic type driver built to modern standards. So the driver cost is not that expensive.
Moondog-
One of your mates, Rod Elliot, has a great website, ESP. His ELF speaker project is almost what you need.
Somewhere in that article, he suggests you might use multiple smaller drivers in parallel, but he doesn't go into a lot of details about this. I built one using eight 6.5 inch drivers in series parallel. If you want more output, you can go with 16 drivers or more.
The more drivers you have, the more your efficiency goes up..... Your radiating area gets larger....required Xmax goes down.....
parts of your house that have never moved before will shake....
You can probably achieve those really ridiculous concert levels you are wanting.
JJ
The best part is that the bass is very articulate, because you are not fighting the drivers' resonance peak.
Moondog55 said:
Well, even two/channel will fall far short of what's needed for low distortion dynamics plus the cabs will be large to go low, forcing you into keeping the sub system.
WRT car sub drivers, they can make excellent tapped horns which can be folded up, but I'm of the opinion that ~80-100 Hz is about as high an XO point as practical.
GM
Jupiterjune greets, I had looked at Rod's site and would consider using that system if I thought I had the skills to work on the electronics.
Andy! I do agree with that, I had just forgotten how loud and good a full symphony sounded when in musical flight, reaching those levels at home seems to be acheivable but that much noise in such a small space isn't going to sound like the real thing is it??
Making plans for new house and new system too.
Bigger is better, and I am going to start saving for some larger drivers.
As a rule of thumb is it correct to say that the lower the resonance of the bass driver the better, and some of those avaliable with low Fs are relatively inefficient ( 82- 88dB) if you have to pick two out of three criteria LowBass, size and efficiency I will happily pick low bass and efficiency and put up with large size.
Are there any pro drivers out there with really low resonant frequencies say 18 Hz
Andy! I do agree with that, I had just forgotten how loud and good a full symphony sounded when in musical flight, reaching those levels at home seems to be acheivable but that much noise in such a small space isn't going to sound like the real thing is it??
Making plans for new house and new system too.
Bigger is better, and I am going to start saving for some larger drivers.
As a rule of thumb is it correct to say that the lower the resonance of the bass driver the better, and some of those avaliable with low Fs are relatively inefficient ( 82- 88dB) if you have to pick two out of three criteria LowBass, size and efficiency I will happily pick low bass and efficiency and put up with large size.
Are there any pro drivers out there with really low resonant frequencies say 18 Hz
Moondog55 said:
I don't think it'd be all that difficult for you.. might actually be a good starter project. However, there are other ways to achieve a very similar result, rather than using that circuit. Besides that, it seems to me as though it'd pretty much suffer from the same drawbacks as any heavily EQ'd subwoofer system (more cone movement and distortion from the driver itself than any other type of design, and the requirement of TONS of power relatively mediocre SPL's). They can sound very good though when done right, as long as you don't need insane amounts of output.. and don't mind spending a ton for adequate drivers and amplification.
Moondog55 said:
Although I had to read that sentence twice
, you're 100% correct and on the right track.. except for the 'lower the resonance of the bass driver the better', as that depends on the design the driver will be used for.Absolutely not, or at least not that I'm aware of. It's a big part of the reason why they're so efficient, and what makes them 'pro drivers' in the first place. You'll come across 18" pro woofers every now and then with an Fs as low as 25 Hz or so, but they'll likely have a very low Qts, so they won't go anywhere near that low.. at least not without an insanely massive enclosure so large it'd be impractical, and even then, it'd probably be very limited in output due to reaching xmax so soon from the huge enclosure it's in.
On the other hand, there are other ways to go about obtaining high efficiency in the lower frequencies.. Multiple woofers and tons of power (expensive, wasteful, possible lack of output, tons of power required), horns (difficult to design and often limited in the lowest octaves), etc. I think a lot of people just settle for low efficiency bass though, regardless of the rest of their setup. However.. I've toyed off and on for years with the idea of making a simple-to-build transmission line subwoofer for use below 50Hz.. using an 15-18" pro woofer with an Fs in the mid 30's+ (has to be to fit under the ceiling). Something like the Eminence Kilomax Pro-18 might be a really good choice for this type of design, if not something else with an Fs a bit higher. If all went well enough, I'd most likely build a few more after that. If you haven't seen it already, check out the old El Pip-O article by Nelson Pass. TL's can't get much simpler than that. It does have it's negatives though, but I would think that using it below 50Hz or less with a 4th order slope should virtually eliminate them. http://www.passdiy.com/projects/el-pipe-o-1.htm
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