VanJerry said:
You can't build a box that doesn't resonate. You can only control where they do resonate & position it such that it is unlikely to get excited. This is the philosophy behind B&Ws Matix (and my boxes for that matter).
Dealing with the back wave is a completely different issue.
We have found bamboo plywood to be a very nice building material sonically. One has to take special care while building thou.
dave
That's right - back wave. So that's separate. Thank you Dave. Then that's where angular and curved enclosures come in. What approach do you like to use in your aperiodic designs?
That'd be the plyboo? Is there a particular brand or supplier of low-chemical you like? Alternatively I considered making my own by laminating 2 layers of low-chemical vertical flooring - it might be cheaper than plyboo.
You would mean shreading?
That'd be the plyboo? Is there a particular brand or supplier of low-chemical you like? Alternatively I considered making my own by laminating 2 layers of low-chemical vertical flooring - it might be cheaper than plyboo.
You would mean shreading?
udailey said:
Hi there udailey,
Great to hear the sound of your Super 12" matches that nice curve.
"5%" to get to a level response is quite significant information to a guy concerned about weight at low volumes. I understand this can vary with the amp but can I take this to mean the bass "comes alive" fairly easily? Was that somewhat as true on your HK?
MJK would say that may have more to do with pairing that amp with Commonsense's recommended 2.8 cu. ft. bass reflex in which case some more details about that experiment could provide me with some good direction- if you could tell me what it was that you specifically didn't like when you ran your Nirvana's on the AVR 135 that might help guide me to a happier enclosure design for the Denon.
I'm taking Nihilist's suggestion of a sealed seriously. That might fair better with the SS amp by effecting the system impedance. The other 2 choices I'm looking at closely for Nirvana 10's or 12's are aperiodic and even a Metronome - there's measurements for both a 10" and a 12" in that table.
But, if I had to build an amp - I'm willing to do what it takes. (By the way, I also have an HK "all digital path" DPR 1001 7.1 receiver. Might that share any attributes of a chip amp? I've also got an old school Kenwood KR-A47 stereo receiver and there's more where that came from on Craig's list... Though building would probably be a better experience...)
You've got me down pretty good except that I'm a lot more keen on having the FR experience than I want to actually get down to cutting and gluing: the research has been a bit exhausting. It's funny though - I designed and fabricated quite a few of my possessions so far - short of cars and computers of course. So I have the DIY drive all right. Just that my level of exuberance is usually overshadowed by my sense of standards. Can't help but need the food to taste good and the music to sound nice.
But I agree. There is a lot to be said for starting with a reference point that can be personally experienced and moving from there. Especially when in new territory like this. Precious few frames of reference. I'll settle down soon. I couldn't survive this phase much longer any way. Im looking forward to relaxing and just appreciating the goods.
Indeed, I almost let myself forget my beginnings... As for someone who has used them - well really that'd be good people like you and ranger3.
You're right how there's been a noticeable quiet over these drivers. I think things like the larger AN's not fitting into the DIY mainstream with their high VAS and Commonsense's tendency to emphasize BR to the exclusion of pretty much anything else means some otherwise satisfied people probably think twice about going public with their stories. Those two Affordable Audio reviews by John Hoffman, along with his personal posts - were pretty trustworthy and informative too.
AffordableAudio Super 12
AffordableAudio Super 8
Wish I had an SPL meter to tell you exactly because saying "low volume" is pretty vague since definition can be so different between you and I. So, what I am getting at is that at very low volumes I don't find it worth listening. Maybe the enclosure is to large to start helping the bass at this low volume. I would compare the volume I am describing as equal to a private conversation. Not a whisper at all, but that volume people drop into when they have some gossip and they dont want others to hear it. I like to listen at super low level when my daughter is sleeping. Listening at just above whisper level loses something.
I pretty much agree with what BVAN was telling you about low volume listening a while back. I would love to have bass boosted as the volume got quite low.
I had a big rant, suprise suprise, in here about how great ChipAmps are compared to my AVR and everything before it. Deleted it because none of it matters because its not a reality until you hear it. Then on top of that its not the best DIY amp, just the easiest and it does a great job with the ANs. I dont think my amp determines the enclosure as much as the driver does. That combined with not being qualified to answer enclosure questions leaves me with no direct answer for you.
You live about 58 miles from Planet10
I mean, if he and I were good buddies (and I hold him in high regard) I would be over there in a flash for a listening session. Even a 3 minute one. Not that he has any ANs but I think you would have one of those AHA moments if you could listen to something that is of FrugalPhile quality. Then your decision making is going to get easier. You have no point of reference in DIY yet so its tough to drop down the cash and the work.
I bet he at least knows someone in your town who has a pair of DIY Fostex.
map link
What!?! I never saw that before. I wonder if anyone has built them yet.Take this with a grain of salt cuz I am on the ChipAmp bandwagon at the moment, but YES building a ChipAmp is like a DIY right of passage. You will have another AHA moment. For me I have had 3 in the last month. Craziness and such a great thing to have happen recently. The ANs The Chippy and The PS1 all changed the music for the better so much that my view of everything music related has been turned on its head and I am thrilled. Many people remark that the LM3886 is similar to amps worth thousands. The gaincard that started this can clock in at 6500.
http://www.6moons.com/audioreviews/47labs5/gaincard.html
But you can build something similar for about $150-$200 depending on how exotic you go with components. You dont need exotic by the way.
www.chipamp.com and www.audiosector.com if you get interested and decide to build one I will be more than happy to help select parts. Another DIY standby is www.apexjr.com for inexpensive toroids/caps/interconnect/switches
I think, really, this is the ticket. You really have to know where youre starting from. Neither the Fostex nor the ANs are a set of Polks or JBLs. This is a whole nother realm. It is for me anyway.
You know what I really like listening to? One AN and one Fostex. I have to crank the Fostex to get it to keep up with the AN but something is there that is not with either 2 Fostex or 2 AN. Its nice and it makes me think that I would probably enjoy 2 of each if I had a HT setup. See, you dont have to choose one exclusively when you are going for HT
Man I wrote a lot and all I needed to say was this:
I am no longer impressed with commercial amps. The dont sound as good as the ChipAmp. Regardless of enclosure.
Try building one. Its easy and inexpensive and rewarding. Its eye/ear opening.
Fostex and AN have their strengths. In the enclosures I have so far I prefer the AN. I like them playing together, maybe you would to.
Its your decision and I dont think you can force the perfect decision no matter how much research you do. Unless you are MJK. He can.
Goodnight all,
Uriah
Well Uriah,
Sounds to me like if your bass is alive down to just above a private conversational level that the Super Cast 12" with its significantly more dB's below 80 Hz should meet my requirements just fine so i appreciate your description. Plus, I don't believe you have a sub with that AN whereas I have the sealed servo Rythmik. It's variable 12-24 dB/Oct so I'm covered even if I go with Nihilist's sealed and have a need for a natural 12 dB/Oct roll out below 80 Hz.
Oh, and please don't feel I was asking you for enclosure advice. I thought if I heard the particular symptoms - as it were - that you experienced with your SS amp, knowing your enclosure is the 2.8 BR, I could cross-reference with the various characteristics of the basic enclosure types myself. Then pick a match. This is why I ask if you can just give a couple of details about the actual sound you found less than satisfactory with the HK simply as one example of a typical SS amp?
It is true I would have probably quite a darn many "AHA's" if I listened to Planet10's wares. (There's a meet later this summer I might be able to make.)
But maybe I haven't done a good job of updating my position. Basically I began this thread having a gut instinct my destiny was to try the AN Cast 10 or 12. But I confess I was pretty insecure because I felt simply overwhelmed with all there was to know even to just begin to make any kind of deliberate decisions.
So from the start I included a counter position leveraging what I was more familiar with in the form of the 2-channel XBL options of GR Research. I regularly replaced this counter position as the thread ran on and I researched whatever was mentioned to me. This included several of those FrugalPhile options. None of which involved drivers larger than 8" let alone AN's but they seemed very attractive indeed. When I hit that amp concern a little ways back it stimulated me to look at designs using other drivers - principally from CSS - in earnest. And these were very attractive too. I confess to becoming intoxicated by the very ideas of altogether quite a few of them. So to make a long story short... after a listen I'm afraid I would likely come away committed to building at least 3 of them!
So of course I understand your own chip intoxication. Good times
And so, for me now, it's simpler just to return to my gut this first time round: Build a 10 or 12 Cast AN using the SS amp. Get that first reference down. Though remaining always, throughout, open to having any basic flaw in my direction pointed out to me.
I thought I'd done some research before but since I began this thread I feel like I've gone through something similar to what Johnny Mnemonic regularly went through for a living and at one point I'll admit to losing my focus. But, I've managed to build a back bone thanks to the new knowledge I've gained. And I think I know better now how to conduct a thread about anything. And I apologize to any readers who came looking for knowledge and found this thread meandering at times.
Sounds to me like if your bass is alive down to just above a private conversational level that the Super Cast 12" with its significantly more dB's below 80 Hz should meet my requirements just fine so i appreciate your description. Plus, I don't believe you have a sub with that AN whereas I have the sealed servo Rythmik. It's variable 12-24 dB/Oct so I'm covered even if I go with Nihilist's sealed and have a need for a natural 12 dB/Oct roll out below 80 Hz.
Oh, and please don't feel I was asking you for enclosure advice. I thought if I heard the particular symptoms - as it were - that you experienced with your SS amp, knowing your enclosure is the 2.8 BR, I could cross-reference with the various characteristics of the basic enclosure types myself. Then pick a match. This is why I ask if you can just give a couple of details about the actual sound you found less than satisfactory with the HK simply as one example of a typical SS amp?
It is true I would have probably quite a darn many "AHA's" if I listened to Planet10's wares. (There's a meet later this summer I might be able to make.)
But maybe I haven't done a good job of updating my position. Basically I began this thread having a gut instinct my destiny was to try the AN Cast 10 or 12. But I confess I was pretty insecure because I felt simply overwhelmed with all there was to know even to just begin to make any kind of deliberate decisions.
So from the start I included a counter position leveraging what I was more familiar with in the form of the 2-channel XBL options of GR Research. I regularly replaced this counter position as the thread ran on and I researched whatever was mentioned to me. This included several of those FrugalPhile options. None of which involved drivers larger than 8" let alone AN's but they seemed very attractive indeed. When I hit that amp concern a little ways back it stimulated me to look at designs using other drivers - principally from CSS - in earnest. And these were very attractive too. I confess to becoming intoxicated by the very ideas of altogether quite a few of them. So to make a long story short... after a listen I'm afraid I would likely come away committed to building at least 3 of them!
So of course I understand your own chip intoxication. Good times
And so, for me now, it's simpler just to return to my gut this first time round: Build a 10 or 12 Cast AN using the SS amp. Get that first reference down. Though remaining always, throughout, open to having any basic flaw in my direction pointed out to me.
I thought I'd done some research before but since I began this thread I feel like I've gone through something similar to what Johnny Mnemonic regularly went through for a living and at one point I'll admit to losing my focus. But, I've managed to build a back bone thanks to the new knowledge I've gained. And I think I know better now how to conduct a thread about anything. And I apologize to any readers who came looking for knowledge and found this thread meandering at times.
Keep the thread going and let us know what you do. Hopefully you will document your build process and post it for us.
When you make your enclosure make sure to keep your damping material to 1" thick. If you compress it down or if it comes as 1" thick doesnt matter per David Dicks, but his instructions say to use 2-3 inches and when I questioned him he said he needed to update them to 1".
Glad you are taking the plunge You have to start somewhere and you did enough research to know that where you are starting from is not a risky place.
Uriah
When you make your enclosure make sure to keep your damping material to 1" thick. If you compress it down or if it comes as 1" thick doesnt matter per David Dicks, but his instructions say to use 2-3 inches and when I questioned him he said he needed to update them to 1".
Glad you are taking the plunge
You have to start somewhere and you did enough research to know that where you are starting from is not a risky place.Uriah
Sure will, Uriah.
It is not likely that I will go for a simple BR. I'll stay with someone's established design but taking best advantage of the sub I'm leaning towards sealed or aperiodic - plus that Metronome is egging me on from out in left field and it's been cleared specifically for the AN 10 and 12 including all the measurements. I'd like to find out how its sound might differ. Thanks to Nihilist I already have a good idea about the sealed/aperiodic.
But for the BR, yes, I noted some changes from Dick's original version were made for the build used in the Affordable Audio review.
For those unfamiliar with this review the author John Hoffman made 3 major changes to the Commonsense plans for a 2.8 cu. ft. BR for the Super 12:
1. The internal wire. Hoffman went with Audio Magic silver ribbon for best performance across the audio spectrum.
2. The amount of internal damping. To maintain a lively and dynamic character Hoffman chose 2" on the rear wall and 1 1/2 everywhere else.
3. The length of the port. On the one port version Hoffman built it was lengthened to 6" to improve the detail in the LF.
For my own build I still find it difficult to choose between the Cast 10" and the 12". In my correspondence with David Dicks of Commonsense he tells me the 12" is a bit better in the midrange while the 10" is a bit better in the highs. But most people who come for a listen can't really tell a difference and he suggests if he had to quantify it would be about 5%.
That's not an evasive answer as far as I'm concerned. It'd be a consistent story for two equally good drivers that basically only differ for being slightly optimized towards HF or LF depending on what the builder fancies. Unfortunately I've never personally leaned one way or the other being an advocate of absolute neutrality in the past. Oh well, ...probably go with the 12" just because I wanted to try a BIG FR, it guarantees the best midrange, most LF weight, and I can always risk adding a minimally crossed supertweeter in the distant future but it's hard to glue on more cone to turn a 10 into a 12.
It is not likely that I will go for a simple BR. I'll stay with someone's established design but taking best advantage of the sub I'm leaning towards sealed or aperiodic - plus that Metronome is egging me on from out in left field and it's been cleared specifically for the AN 10 and 12 including all the measurements. I'd like to find out how its sound might differ. Thanks to Nihilist I already have a good idea about the sealed/aperiodic.
But for the BR, yes, I noted some changes from Dick's original version were made for the build used in the Affordable Audio review.
For those unfamiliar with this review the author John Hoffman made 3 major changes to the Commonsense plans for a 2.8 cu. ft. BR for the Super 12:
1. The internal wire. Hoffman went with Audio Magic silver ribbon for best performance across the audio spectrum.
2. The amount of internal damping. To maintain a lively and dynamic character Hoffman chose 2" on the rear wall and 1 1/2 everywhere else.
3. The length of the port. On the one port version Hoffman built it was lengthened to 6" to improve the detail in the LF.
For my own build I still find it difficult to choose between the Cast 10" and the 12". In my correspondence with David Dicks of Commonsense he tells me the 12" is a bit better in the midrange while the 10" is a bit better in the highs. But most people who come for a listen can't really tell a difference and he suggests if he had to quantify it would be about 5%.
That's not an evasive answer as far as I'm concerned. It'd be a consistent story for two equally good drivers that basically only differ for being slightly optimized towards HF or LF depending on what the builder fancies. Unfortunately I've never personally leaned one way or the other being an advocate of absolute neutrality in the past. Oh well, ...probably go with the 12" just because I wanted to try a BIG FR, it guarantees the best midrange, most LF weight, and I can always risk adding a minimally crossed supertweeter in the distant future but it's hard to glue on more cone
to turn a 10 into a 12."..................but it's hard to glue on more cone to turn a 10 into a 12."
F'in right.
Aperiodic is = to using a Scan Speak or Dynaudio vent.
Bass will be smoother, but will lose slam/drive/snap.
Tightest bass is with a sealed/stuffed cabinet , but the more stuffing you add reduces "snap" and "slam".
Like anything else , it's a tradeoff.
If you want alot of "slam" , then tune the cab to about 50-60hz or so.
Sealed cab is eay to tune. Just build the biggest cab your wife will deal with and adjust stuffing to suit your sonic/musical taste.
Hard to go wrong with OB or Sealed.
PS: Small drivers can sound good, but big drivers can sound GREAT !
.....................Blake
F'in right.
Aperiodic is = to using a Scan Speak or Dynaudio vent.
Bass will be smoother, but will lose slam/drive/snap.
Tightest bass is with a sealed/stuffed cabinet , but the more stuffing you add reduces "snap" and "slam".
Like anything else , it's a tradeoff.
If you want alot of "slam" , then tune the cab to about 50-60hz or so.
Sealed cab is eay to tune. Just build the biggest cab your wife will deal with and adjust stuffing to suit your sonic/musical taste.
Hard to go wrong with OB or Sealed.
PS: Small drivers can sound good, but big drivers can sound GREAT !
.....................Blake
Hi Nihilist,
I hear you. For me those qualities fuel a couple of specific reasons to choose a sealed design:
First is how it allows me some continuity with what I'm used to: all my regular 2-way speakers were also chosen on the basis of being accurate, clean and detailed. In a word, "snappy." I'm thinking a sealed version of a Cast 12" is likely to deliver an accurate, clean, powerful, and detailed sound effortlessly.
The second goes with the first. As much as it'd be good for music, what you describe turns out to also be ideal for my kind of HT sound as well.
This thing about the aperiodic originally when I was sweating the size issue was to enable adequate performance for high VAS drivers in the smallest size cabinet. However my wife and I have become readjusted to the idea of something as big as 2 or 2.5 cu. ft. after seriously contemplating some of those large horn designs a short while back. My wife would actually prefer the Metronome now after she saw the Cain SuperAbby which she also liked. So 2.5? ...It's interesting how things get relative.
Then when the amp issue came up I learned aperiodic can help lower a speaker's impedance around the LF where it's greatest. So I thought as a hedge against discovering amp trouble with the SS Denon I would construct a sealed box with an optional place to swap in a vent. Of course, the Qts of the Cast 12 at 0.488 is nearly up to that of the CSS FR125 at 0.59 so choosing the 12 would make that issue pretty much go away, I'd think.
Also, I just came across this from an older post from ScottG . Looks to me like this is why aperiodic isn't as good for a large FR whereas - say, Planet10 can benefit from it because there he's using smaller full rangers:
Which leaves just the sealed and the Metronome.
A few quick questions Nihilist?
Can you define "smoother" - I'm happy to look things up but this one could go a lot of different ways.
I get it, hence build the biggest box possible - that way I wouldn't have to add as much or hardly any stuffing so I'd get tightness and not lose snap and slam. But I read if the box is TOO big things get flabby too, so how much bigger than 2 cu. ft. might you suggest. Or, is there a formula?
This is still for sealed? How does one tune for specific freqs? I thought that was a BR concept.
Thank you
I hear you. For me those qualities fuel a couple of specific reasons to choose a sealed design:
First is how it allows me some continuity with what I'm used to: all my regular 2-way speakers were also chosen on the basis of being accurate, clean and detailed. In a word, "snappy." I'm thinking a sealed version of a Cast 12" is likely to deliver an accurate, clean, powerful, and detailed sound effortlessly.
The second goes with the first. As much as it'd be good for music, what you describe turns out to also be ideal for my kind of HT sound as well.
This thing about the aperiodic originally when I was sweating the size issue was to enable adequate performance for high VAS drivers in the smallest size cabinet. However my wife and I have become readjusted to the idea of something as big as 2 or 2.5 cu. ft. after seriously contemplating some of those large horn designs a short while back. My wife would actually prefer the Metronome now after she saw the Cain SuperAbby which she also liked. So 2.5? ...It's interesting how things get relative.
Then when the amp issue came up I learned aperiodic can help lower a speaker's impedance around the LF where it's greatest. So I thought as a hedge against discovering amp trouble with the SS Denon I would construct a sealed box with an optional place to swap in a vent. Of course, the Qts of the Cast 12 at 0.488 is nearly up to that of the CSS FR125 at 0.59 so choosing the 12 would make that issue pretty much go away, I'd think.
Also, I just came across this from an older post from ScottG . Looks to me like this is why aperiodic isn't as good for a large FR whereas - say, Planet10 can benefit from it because there he's using smaller full rangers:
Which leaves just the sealed and the Metronome.
A few quick questions Nihilist?
Can you define "smoother" - I'm happy to look things up but this one could go a lot of different ways.
I get it, hence build the biggest box possible - that way I wouldn't have to add as much or hardly any stuffing so I'd get tightness and not lose snap and slam. But I read if the box is TOO big things get flabby too, so how much bigger than 2 cu. ft. might you suggest. Or, is there a formula?
This is still for sealed? How does one tune for specific freqs? I thought that was a BR concept.
Thank you
OK, the cast 10 or 12 AN driver look very interesting for the price and have no real full range driver competitors at this diameter.
Cast 12
fs = 36 Hz
Qts = 0.488
Vas = 252 liters
Cast 10
fs = 34 Hz
Qts = 0.254
Vas = 173 liters
For a sealed box, how big a box are you considering and what will be the resulting Qtc and Fc? It would seem like a pretty big box would be required and I am still wondering how low the bass would go for either driver. If you are going to use a sealed box, the tuning frequency will be higher and you will need a sub to produce any deep bass. If that is the case, why not use a smaller driver and mate it to the sub? I would think that a smaller driver would produce a better midrange and high frequency response in a much smaller package.
Have you sized a Metronome enclosure for either of these drivers? It will be huge!
I think it would help you narrow the field of potential drivers if you scoped out box sizes and expectations for the SPL response for each candidate. Don't default to the one size fits all Common Sense Audio 2.5 cabinet, calculate the expected response using one of the freeware programs to see what you will get. I am not convinced that the 2.5 cabinet is the right size enclosure.
Hi Martin,
What you ask will take more time to answer fully so I'm shooting this off in the meantime.
For Qtc I'm guessing anything from 0.5 to 0.8 would be fine - curve wise. I'm just looking for something my SS Denon will drive. For SPL's Definitely don't need huge volume at all so hoping there's room for distortion and control compromises. In fact this system - and a lot of the rationale for a large FR driver, is low level nuance etc.
As far as Fc, vital information is that I have a 12" paper coned GR Research SW-12-04 Rythmik sealed servo sub with variable 12-24 dB/Oct slope (PEQ version.) Pretty flexible.
Except I wanted to avoid localization so my intention is to cross at 80 Hz or below otherwise have to restrict sub location to front center. Might be tight fit and definitely a so so room response.
I understand the VAS indicates huge enclosures but people are reporting good results with 2.5 cu. ft. in BR including John Hoffman. Here's his audioasylum post: (Mister Pig) I believe there's something quirky going on here. Is good great? I'm OK with that. But that's BR. It's my baseline. Surely, I ask, we can do better than that? If not, BR's a fall back. Or I could give OB a shot.
But my biggest inspiration for this outrage is this post by victoriobenatti using a 140 liter sealed enclosure (4.9 cubic feet) with a 400 mm wide baffle. But this is without a sub!
So, admittedly I'm looking to underbid this size leveraging my sub to the max. If you feel there is a happy medium between 2.0 and 4.9 I'm open. Surely if 4.9 is adequate without a sub I can take a foot or two off this? (Besides WAF the room is only 11x15 and has bookcases etc so in terms of human ergonomic/architectual sense of space a little pressed.) Plus I don't mind if the penalty is a little extra in the upper bass - it's for HT - it's "showbiz!"
The key for not wanting a smaller driver mated to the sub is the exceptionally unusual midrange provided by the AN Cast 12, the low volume possibilities and the fact that for HT I wouldn't mind the weight in the upper bass/lower mids and fear undersizing. For better or for worse I crave that particular "effortlessness" I've heard only size or incredibly powerful amps provide. What's the deal with effortlessness? I need to relax - can you tell?
I know this is a contrarian project. Maybe I'm courting the ho hum. But I'm following my gut. There's land there! I feel it. And I've gathered enough anecdotal evidence not to feel I'm being too reckless.
I've also got something - an advantage in a sense that none of you have... You know what my insurance is? Hey! I'm a nube. What would I know if the result with a 10 or 12 isn't all that good? If I like it. Besides, it'll leave plenty of room for future improvement - isn't that the back end to this hobby? You don't want me to blow it and reach perfection on my first go would you?
As for the Metronome . I just noticed it's excellent AN 10" curve. It may be crazy but if it has sound advantages I'm open to it. Wife is googly over it - that sort of thing.
The size is actually manageable http://www.frugal-horn.com/metronome-table.html]according to this table.[/URL]
AN 10":
Box inner height: 72" (1829 mm)
Box inner base: 14.5" x 12.5" (368 x 318 mm)
AN 12":
Box inner height: 60" (1524 mm)
Box inner base: 24" x 20" (609 x 508 mm)
Martin, a question:
When you look up the Metronome it says the latest version is a ML-TQQT. What might that stand for?
What you ask will take more time to answer fully so I'm shooting this off in the meantime.
For Qtc I'm guessing anything from 0.5 to 0.8 would be fine - curve wise. I'm just looking for something my SS Denon will drive. For SPL's Definitely don't need huge volume at all so hoping there's room for distortion and control compromises. In fact this system - and a lot of the rationale for a large FR driver, is low level nuance etc.
As far as Fc, vital information is that I have a 12" paper coned GR Research SW-12-04 Rythmik sealed servo sub with variable 12-24 dB/Oct slope (PEQ version.) Pretty flexible.
Except I wanted to avoid localization so my intention is to cross at 80 Hz or below otherwise have to restrict sub location to front center. Might be tight fit and definitely a so so room response.
I understand the VAS indicates huge enclosures but people are reporting good results with 2.5 cu. ft. in BR including John Hoffman. Here's his audioasylum post: (Mister Pig) I believe there's something quirky going on here. Is good great? I'm OK with that. But that's BR. It's my baseline. Surely, I ask, we can do better than that? If not, BR's a fall back. Or I could give OB a shot.
But my biggest inspiration for this outrage is this post by victoriobenatti using a 140 liter sealed enclosure (4.9 cubic feet) with a 400 mm wide baffle. But this is without a sub!
So, admittedly I'm looking to underbid this size leveraging my sub to the max. If you feel there is a happy medium between 2.0 and 4.9 I'm open. Surely if 4.9 is adequate without a sub I can take a foot or two off this? (Besides WAF the room is only 11x15 and has bookcases etc so in terms of human ergonomic/architectual sense of space a little pressed.) Plus I don't mind if the penalty is a little extra in the upper bass - it's for HT - it's "showbiz!"
The key for not wanting a smaller driver mated to the sub is the exceptionally unusual midrange provided by the AN Cast 12, the low volume possibilities and the fact that for HT I wouldn't mind the weight in the upper bass/lower mids and fear undersizing. For better or for worse I crave that particular "effortlessness" I've heard only size or incredibly powerful amps provide. What's the deal with effortlessness? I need to relax - can you tell?
I know this is a contrarian project. Maybe I'm courting the ho hum. But I'm following my gut. There's land there! I feel it. And I've gathered enough anecdotal evidence not to feel I'm being too reckless.
I've also got something - an advantage in a sense that none of you have... You know what my insurance is? Hey! I'm a nube. What would I know if the result with a 10 or 12 isn't all that good? If I like it. Besides, it'll leave plenty of room for future improvement - isn't that the back end to this hobby? You don't want me to blow it and reach perfection on my first go would you?
As for the Metronome . I just noticed it's excellent AN 10" curve. It may be crazy but if it has sound advantages I'm open to it. Wife is googly over it - that sort of thing.
The size is actually manageable http://www.frugal-horn.com/metronome-table.html]according to this table.[/URL]
AN 10":
Box inner height: 72" (1829 mm)
Box inner base: 14.5" x 12.5" (368 x 318 mm)
AN 12":
Box inner height: 60" (1524 mm)
Box inner base: 24" x 20" (609 x 508 mm)
Martin, a question:
When you look up the Metronome it says the latest version is a ML-TQQT. What might that stand for?
I really think you need to make some numbers for the closed box design. Try WinISD, or one of the other free box modelers. I think you will be surprised. I am not sure you are going to meet your response goals in anything but a very large box.
The Metronome dimensions you quote are huge. In your small room the size of the enclosure base is going to take up a lot of floor space. Moving them out a foot or two from the rear wall means you will be sitting very close. I suggest taking pieces of newspaper and cutting them to the right external dimensions and placing them on the floor to assess the layout. A cardboard mock up might also be enlightening.
I am not trying to give you a hard time but discussing ideas in posts does not provide the same level of insight as doing the simple design calculations, drawing some sketches, and really thinking about exactly how to build and place the enclosure.
I am going to drop this now because I don't want to rain on your parade.
The Metronome dimensions you quote are huge. In your small room the size of the enclosure base is going to take up a lot of floor space. Moving them out a foot or two from the rear wall means you will be sitting very close. I suggest taking pieces of newspaper and cutting them to the right external dimensions and placing them on the floor to assess the layout. A cardboard mock up might also be enlightening.
I am not trying to give you a hard time but discussing ideas in posts does not provide the same level of insight as doing the simple design calculations, drawing some sketches, and really thinking about exactly how to build and place the enclosure.
I am going to drop this now because I don't want to rain on your parade.
I'd go for the sealed AN box. The 2.8 ambience is supposed to give more bass and a bigger sweet spot than the other AN designs. My little 4.5", sealed, fostex bipoles cross over to a sub ok.
Some of the best sealed boxes i've heard were stuffed to the gills and produced very tight bass. Its vented boxes that seem fussy about stuffing.
Some of the best sealed boxes i've heard were stuffed to the gills and produced very tight bass. Its vented boxes that seem fussy about stuffing.
Thank you Martin,
I assure you are the opposite from giving me a hard time.
I know what I'm proposing looks like some pretty messy stuff. Especially if one were to demand the best reliable results. But when I got back in touch with my original inspiration a few days ago I realized that though using an AN Cast 10" or 12" was a somewhat irrational impulse it seems I need to honor it. I want you to know I'm comfortable with that for a first FR project. ...I never mentioned I actually built a few 2-way speakers in college many years ago but somehow the details are particularly hazy...
I know these will be very close to near-fields. I also studied aspects of architectural design (art college - not architecture) so our space has been well populated by mock ups and full scale outlines. Having made these I totally concede that the more slender 10" Metronome is far more attractive and the 12 would be too big. I only mentioned the 12" Metronome in case it would be superior for technical reasons. And if a sealed 12 had to be 4 cu. ft. maybe I could be clever and design something that didn't seem so bad.
So, sealed, or Metronome, or anything else, I'd like to stick to these 2 drivers. My biggest quandary actually is deciding between them.
The 10 has a fairly significant HF extension and lower VAS for smaller enclosures. Of the 2 it would make the most commonsense use of the sub and make for a pretty manageable sized sealed box. As a flight of fancy a 10" Metronome, though tall is quite slender, and would look and probably sound, as they say, awesome.
The 12 has a lot of established work done with it. And the consensus is that it has the smoothest freq response and finest midrange quality. Though perhaps not very significantly. It's virtue is one of sufficiency . I won't ever wonder what might have been. And this does concern me.
I don't know how much my design constraint (which stresses low level performance) can be better solved in other ways that involve smaller drivers well mated to a good fast sub like the Rythmik sealed servo. But I look at these large FR drivers as offering resources for a different kind of low level solution. A trade-off that results in an organic effortlessness. Low tech. Old school. This solution may well be poorer in some ways. Though by victoriobenatti's description of his Wharfedale Super 12 his would seem to me satisfactory.
But most likely I feel compelled to serve my impulse because I was imprinted by such a sound when I was a child and want to recreate it. Maybe this is not an audiophile project as much as a pyschoacoustic restoration project. I should have said as much earlier in the thread, if I could.
I fear therefore in pursuing this sentimental experiment that I risk tying hands and frustrating competences. So I hope you and everyone here can feel relieved of any sense of responsibility at the nature of the outcome.
I just realized one thing throwing things off is this: it is common understanding that a sealed version of a BR can be smaller - often much smaller. And so I thought, if people can be satisfied with their nonCast 12" AN in a 2.8 cu. ft. BR - which isn't supposed to work at all with a VAS of 291 in the first place, then if I generously offered to the speaker gods that I would make the enclosure no smaller - and even offered to increase it by a half or a foot, using a Cast version offering a significantly smaller VAS of 252, then I should likewise reasonably expect to be at least as satisfied with a sealed box.
The trouble with this logic is: if the 2.8 BR wasn't supposed to work but only did because the AN12 is somehow quirky, - who's to say this quirkiness can be trusted to apply to a sealed treatment?
In the WinISD sim rjbond3rd performed on my behalf on a sealed Cast 12 in Post #7 and #8 it seemed like a 100 litre (3.5 cu. ft) would be OK. Just a little bump between 90 and 200 Hz. Worst case act as a kind of Loudness for lower volumes.
Again, I don't have a PC, but I sure could use a WinISD of the Cast AN 12" in a BR at 300, 100, 50 and 25 (well, preferrably 300, 100, 80, and 50) so I can directly compare these strange fruits. That would be terrific!
Anyone?
Cast 12
fs = 36 Hz
Qts = 0.488
Vas = 252 liters
SPL = 95.474
I assure you are the opposite from giving me a hard time.
I know what I'm proposing looks like some pretty messy stuff. Especially if one were to demand the best reliable results. But when I got back in touch with my original inspiration a few days ago I realized that though using an AN Cast 10" or 12" was a somewhat irrational impulse it seems I need to honor it. I want you to know I'm comfortable with that for a first FR project. ...I never mentioned I actually built a few 2-way speakers in college many years ago but somehow the details are particularly hazy...
I know these will be very close to near-fields. I also studied aspects of architectural design (art college - not architecture) so our space has been well populated by mock ups and full scale outlines. Having made these I totally concede that the more slender 10" Metronome is far more attractive and the 12 would be too big. I only mentioned the 12" Metronome in case it would be superior for technical reasons. And if a sealed 12 had to be 4 cu. ft. maybe I could be clever and design something that didn't seem so bad.
So, sealed, or Metronome, or anything else, I'd like to stick to these 2 drivers. My biggest quandary actually is deciding between them.
The 10 has a fairly significant HF extension and lower VAS for smaller enclosures. Of the 2 it would make the most commonsense use of the sub and make for a pretty manageable sized sealed box. As a flight of fancy a 10" Metronome, though tall is quite slender, and would look and probably sound, as they say, awesome.
The 12 has a lot of established work done with it. And the consensus is that it has the smoothest freq response and finest midrange quality. Though perhaps not very significantly. It's virtue is one of sufficiency . I won't ever wonder what might have been. And this does concern me.
I don't know how much my design constraint (which stresses low level performance) can be better solved in other ways that involve smaller drivers well mated to a good fast sub like the Rythmik sealed servo. But I look at these large FR drivers as offering resources for a different kind of low level solution. A trade-off that results in an organic effortlessness. Low tech. Old school. This solution may well be poorer in some ways. Though by victoriobenatti's description of his Wharfedale Super 12 his would seem to me satisfactory.
But most likely I feel compelled to serve my impulse because I was imprinted by such a sound when I was a child and want to recreate it. Maybe this is not an audiophile project as much as a pyschoacoustic restoration project. I should have said as much earlier in the thread, if I could.
I fear therefore in pursuing this sentimental experiment that I risk tying hands and frustrating competences. So I hope you and everyone here can feel relieved of any sense of responsibility at the nature of the outcome.
I just realized one thing throwing things off is this: it is common understanding that a sealed version of a BR can be smaller - often much smaller. And so I thought, if people can be satisfied with their nonCast 12" AN in a 2.8 cu. ft. BR - which isn't supposed to work at all with a VAS of 291 in the first place, then if I generously offered to the speaker gods that I would make the enclosure no smaller - and even offered to increase it by a half or a foot, using a Cast version offering a significantly smaller VAS of 252, then I should likewise reasonably expect to be at least as satisfied with a sealed box.
The trouble with this logic is: if the 2.8 BR wasn't supposed to work but only did because the AN12 is somehow quirky, - who's to say this quirkiness can be trusted to apply to a sealed treatment?
In the WinISD sim rjbond3rd performed on my behalf on a sealed Cast 12 in Post #7 and #8 it seemed like a 100 litre (3.5 cu. ft) would be OK. Just a little bump between 90 and 200 Hz. Worst case act as a kind of Loudness for lower volumes.
Again, I don't have a PC, but I sure could use a WinISD of the Cast AN 12" in a BR at 300, 100, 50 and 25 (well, preferrably 300, 100, 80, and 50) so I can directly compare these strange fruits. That would be terrific!
Anyone?
Cast 12
fs = 36 Hz
Qts = 0.488
Vas = 252 liters
SPL = 95.474
And finally, the AN 12in CF in a traditional pre T/S aligned cabinet (assuming no volume reduction & vent compensations made).
Volume is 22ft^3 -the assumption with these alignments, BTW, was that you would want maximum efficiency at Fb.
There's basically no such thing as a quirky driver that works in something it's not supposed to, because when you get back to basics, it doesn't. No driver is exempt from the laws of physics. What can happen is that some peple find response imbalances preferable to something more accurate, which is fair enough, but it doesn't alter the fact.
FWIW, these plots do not show room-gain, & assume a light quantity of damping in the respective cabinets.
Volume is 22ft^3 -the assumption with these alignments, BTW, was that you would want maximum efficiency at Fb.
There's basically no such thing as a quirky driver that works in something it's not supposed to, because when you get back to basics, it doesn't. No driver is exempt from the laws of physics. What can happen is that some peple find response imbalances preferable to something more accurate, which is fair enough, but it doesn't alter the fact.
FWIW, these plots do not show room-gain, & assume a light quantity of damping in the respective cabinets.
Attachments
Hello Scottmoose,
I understand your point. But it continues to appear I was correct to believe there is a quirky element at work here. However, according to what I think you are indicating in your charts, that quirky element would be the listeners
OK, you've stimulated me to go back to school on this. So using online calculators...
First of all, the EBP (Efficiency Bandwidth Product):
AN Cast 12: EBP = 68.6
Category: 50 to 90 = flexible enclosure options
OK...
Calculated Sealed Cabinet
Butterworth:
Qtc = 0.707
Vb = 208.47 liters
Fc = F3 = 52.78 Hz
Qtc ----------Vb------------Fc-------------F3-------------Fmax------------Amax
0.75 ------- 168 --------- 55.98 -------- 52.96 -------- 168 ------------- 0.05
0.8 -------- 135.76 ------ 59.72 -------- 53.58 -------- 127.68 --------- 0.21
0.88 ------- 101 --------- 65.69 -------- 55.22 -------- 110.35 --------- 0.58
Meanwhile:
AN Cast 10: EBP = 124.5
Category: 90 or greater = best used ported
T/S suggests ported Vb quite small actually - I'm getting 40 liters? (F3 66.2 Hz)
These 2 drivers are certainly very different!
Here I am looking to use sealed to get better transients/clarity but to achieve even a Qtc of 0.707 for the AN Cast 12 requires 208 liters. My willingness to go another foot to 3.5 cu. ft. (aprox 101 liters) can only garner a Qtc of 0.88 which may actually hurt transient response - I need someone to tell me if that is the case. If so, it seems hardly worth doing without a generosity of volume greater than I expected. Suddenly I have a strong need to know if the transient benefit is still there if I do go up to 168 liters (6 cu. ft.)
Can you help me understand something Scottmoose?
I don't know if Qtc's apply to ported speakers. Is a sealed design with a Qtc of 0.707 still defined as having a better transient response than any well executed BR? Roughly at what point as one increases Qtc's for a sealed enclosure does the transient response resemble that of a BR? eg. Is there still any real transient benefit to a sealed choice at, say, a Qtc of 0.8 or does crossing some number like 0.707 mean everything above this is a losing proposition (only favoring the other parameters such as output I care less about?)
And, if I value only clarity and transient response above most all else, is there any alternative to sealed: some ported design that is more advantageous for this than the rest? And if there are a few, one that might possibly still be more compact than a standard BR?
One last thing. At one time I thought aperiodic would be my ace in the hole, until I learned how this may particularly impact a large cone's performance in the HF. post #69 Is this, as I suspect, true?
I understand your point. But it continues to appear I was correct to believe there is a quirky element at work here. However, according to what I think you are indicating in your charts, that quirky element would be the listeners
OK, you've stimulated me to go back to school on this. So using online calculators...
First of all, the EBP (Efficiency Bandwidth Product):
AN Cast 12: EBP = 68.6
Category: 50 to 90 = flexible enclosure options
OK...
Calculated Sealed Cabinet
Butterworth:
Qtc = 0.707
Vb = 208.47 liters
Fc = F3 = 52.78 Hz
Qtc ----------Vb------------Fc-------------F3-------------Fmax------------Amax
0.75 ------- 168 --------- 55.98 -------- 52.96 -------- 168 ------------- 0.05
0.8 -------- 135.76 ------ 59.72 -------- 53.58 -------- 127.68 --------- 0.21
0.88 ------- 101 --------- 65.69 -------- 55.22 -------- 110.35 --------- 0.58
Meanwhile:
AN Cast 10: EBP = 124.5
Category: 90 or greater = best used ported
T/S suggests ported Vb quite small actually - I'm getting 40 liters? (F3 66.2 Hz)
These 2 drivers are certainly very different!
Here I am looking to use sealed to get better transients/clarity but to achieve even a Qtc of 0.707 for the AN Cast 12 requires 208 liters. My willingness to go another foot to 3.5 cu. ft. (aprox 101 liters) can only garner a Qtc of 0.88 which may actually hurt transient response - I need someone to tell me if that is the case. If so, it seems hardly worth doing without a generosity of volume greater than I expected. Suddenly I have a strong need to know if the transient benefit is still there if I do go up to 168 liters (6 cu. ft.)
Can you help me understand something Scottmoose?
I don't know if Qtc's apply to ported speakers. Is a sealed design with a Qtc of 0.707 still defined as having a better transient response than any well executed BR? Roughly at what point as one increases Qtc's for a sealed enclosure does the transient response resemble that of a BR? eg. Is there still any real transient benefit to a sealed choice at, say, a Qtc of 0.8 or does crossing some number like 0.707 mean everything above this is a losing proposition (only favoring the other parameters such as output I care less about?)
And, if I value only clarity and transient response above most all else, is there any alternative to sealed: some ported design that is more advantageous for this than the rest? And if there are a few, one that might possibly still be more compact than a standard BR?
One last thing. At one time I thought aperiodic would be my ace in the hole, until I learned how this may particularly impact a large cone's performance in the HF. post #69 Is this, as I suspect, true?
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