Correction, I meant ieales, this forum operates a bit differently than I am used to.
I have built quite a few crossovers and never seen the formula written as you have and looked it up, could not find it anywhere.
* the same as x ?
R the same as impedance?
Thanks,
Rick
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I'm not able to respond directly to the OP's first question, but according to my experience the choice of a sub (or more than one) depends also very much on your room and its acoustics - and, of course, on the quality of the components in your stereo system (low, middle, consumer, high end).
I assume nobody out there knows or remembers the make of the sub I use: Acustik-Lab Stella Novus (original spelled name), a Swiss made component which was very in demand in Asia in its time (and very costly, unfortunately). It allows settings in many ways, which was prior to today's DSP. (The company no longer exists.) So my favorite crossover setting is 42 Hz...quite discreet. With DSP and today's choice of subs you may find happiness, too.
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Acoustic-Lab Stella Novus sub, 15 – 500 Hz, adjustable, w/ remote control
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@akg_ca --
Didn't see your post until after I had mine posted. You make excellent points.
@mijostyn --
Re: driver size, I absolute agree with "The notion that larger drivers are "slower" is mythology to the max." It may (or may not) be interesting to note that the digital IMAX cinemas for a few years now have been using subs each comprising a quad array of 12" woofers (looks like (modified) Eminence LAB12's). I believe they usually have about 6 or 8 of those suckers installed in each theatre, and they're very powerful and clean sounding. Cinemas usually go with a number of ported dual 18" subs while some newer installations use 21"-loaded cabs, ported as well, but in any case it's interesting to see IMAX going the deviating route with multiple 12" woofers. Whether this is a consequence of a possible issue with lack of cone control in bigger drivers, I don't know, but in large cinema installations there'll be prodigious subs cone travel for sure.
The question is how lack of cone control in larger drivers (i.e.: 15" on up) relates to a domestic setting. A larger cone may be more difficult to control, but it also has to move less for a given output, and for cone control to be an issue you need cone travel to speak of. The cones of the 15" B&C woofers in my dual corner-loaded tapped horn subs only vibrate up to a few mm's at most at SPL's that seriously pressurizes the room; lack of control is a nonissue here, believe me. Remember the horn on the front side of the driver acts as a force multiplier, so with the combined and summed output of the backwave you have an effective air radiation about 3x that of a 15" direct radiating driver. And there are two of them, corner-loaded, hence it figures why the cones only move so very little, also explained with them having excursion minima at the tune. Bass like that doesn't force itself on you at ground level, but simply energizes the whole space around you very smoothly and effortlessly. Bass just happens as opposed to feeling delivered with effort.
Yes, big cabs dominate the room, as my TH's would testify at 20cf. each. Corner-loaded though don't I feel it to be an issue, but seeing them out in the open they're just huge.
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Absolutely there are differences between subs, each woofer or sub woofer. The size of the woofer, whether sealed or ported, sealed seems boomer, to me. Ported is more defined and crisp. The design or choice of physical materials and shape and size of the speaker, if it’s a single or tower dual woofer, the size and shape, the thickness of the cabinet, power of the amplifier and if it’s external or internal, cross over points, weight, mine is nearly 90lbs. Aluminum woofers dual 10”, and internal amplifier with the ability to easily go down to 19 hertz. Price point is a good way to asses quality, mine is a 6000.00 + new sub and is a direct from manufacturer purchase. I would compare it to Rel but better vs old Velodyne which made awesome subs along with Sunfire and todays big market players are SVS, Hsu, And other small brands. Just like how no two speakers sound the same from different manufacturers the same goes for subs. Some work best for music other home theater applications, some can do both. You just need to try out what works. It’s a budget based.
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I figured out how to take care of my crossover needs, two good .022uF caps, $5-650 Each, depends on how tree bark I smoke:)
After more research I will select the best ones for the cost which means $20-100 more likely on the lower end of that. The exponential cost to get better is something I can live without.
Great to be lifelong DIY, my sub setup would cost many times more to get even close if I bought a manf one.
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the big difference seems to the price. ....the more you pay the more you expect. the more you pay the deeper the base, ( according to the specs ) big trap.
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@punkrock67 , That is odd because most people that I know think the ported woofers are boomy and the sealed ones tight and controlled.
@phusis , I wish I could find the link but is slow mo's an 18" woofer under a strobe actually wobbling under light power. One side starts moving before the other and goes downhill from there. The excursions are not very far.
I feel the most comfortable with 12" drivers and you can get to the same place by using multiples. I keep doubling the number until I get what I want. Next stop is 8.
I saw Marcus Miller and Mike Stern at the Blue Note in NYC last month and I could feel Marcus's E string vibrate. It is that kind of authority I would like to get at home. I have great bass, just not that great. I know there are some recordings that can do it like Supertramp's Crime of the Century or any number of Dave Holland Albums and Jaco albums not to mention Organ works.
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Are all REL subs made in China or just their lower-priced models? SVS Headquarters/factory is close to me here in Ohio. I've been quite happy with SVS. I am curious if a ZU sub would be a better fit for my ZU omen defs.
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@larry5729 , it is painfully easy to beat Rel subs. The problem is the only commercial manufacturer to do it is Magico. A private citizen that is a competent wood worker can do it with their hands tied behind their back. You use balanced force design like Magico and make the enclosure even stiffer.
@parker65310 , I used DIvas for 6 years or so and I could never get subs to match perfectly. This was before DSP came along. I returned to ESLs and with DSP have no issues with integration so, I am sure with proper digital bass management it will be easy and a huge benefit. Like ESLs ribbons do not like making deep bass. They can do it but they do not like it.
@ieales , Rel subs are made as well as any commercial subwoofer. If you are comparing them with other subs on the market. They have two issues. I hate their method of integration and it is easy to get better subs if you build them yourself. I can do things that are totally impractical if you want your sub to come in at a reasonable price and take less than a century to build. I am not trying to pump up my ego either I mean this in all sincerity. I can do better than the subs I have now but the fellow that calibrated my projector (this is his real profession not a side line) related it was the best bass he ever heard. Frankly, I think they are ugly and a bit soft. It was a good performance for 20 years ago but I have learned a lot since then and am in the process of building a new set. Unfortunately, they are competing will things I have to do for the wife and the wife always wins. It is going to be a little while yet. I was hoping this Summer. Time Waits For No One.
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“Rel subs are made as well as any commercial subwoofer. If you are comparing them with other subs on the market. They have two issues. I hate their method of integration and it is easy to get better subs if you build them yourself.”
@mijostyn It appears you have no direct experience with REL subs in your system and that’s quite ok. No disrespect to DIY’s community, but every DIY bloke thinks whatever ‘they’ can do, I can do it better. And please define better, what’s better or best to you or your fellow could easily be ‘good enough’ in someone else eyes. As humans we often tend to judge things based on our personal experiences and express opinions driven by our personal biases :-)
In my 30 years of audiophile journey, I have gotten my hands dirty in quite a few DIY projects. My experience have taught me to recognize and appreciate the differences between DIY and commercial grade builds.
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@lalitk , I have played with several Rel subs but not in my system. Their version of sub integration is designed for the lowest common denominator and it performs like the lowest common denominator. Sorry for being harsh but this is the honest truth.
Many people think DIY projects are second rate at best. It depends on the intelligence, experience and skill of the people involved. The ability of companies to get subwoofers to market include a bunch of economic factors that do not apply to the DIY individual.
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“Sorry for being harsh but this is the honest truth.”
@mijostyn Don’t we all have our own version of truth?
“Many people think DIY projects are second rate at best. It depends on the intelligence, experience and skill of the people involved.”
I am looking forward to your new set of subs, please do post good pictures before you hide them in the corner. My best to you!
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Rel subs are made as well as any commercial subwoofer.
Don't think I said anything about their build quality. My objection to them is the direction the company took. More bling and flash rather than useful features. WAF vs HPF
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Hey ryder,
Not sure if this is the kind of information that you are looking for. In my system I am currently using 2) SVS SB4ooo's, 1) Rythmik F12SE and 1) REL S5 SHO (predecessor to the S812). In my opinion the Rythmik has a slightly better sound than the SVS and both of them are better than the REL. I had to slightly modify the REL in order for it to compete with the other two. Both the SVS and the REL have more output power than the Rythmik. The SVS was easiest to integrate due to its phone app. The Rythmik was a little more cumbersome because you had to make the adjustments at the cabinet and not the listening position and REL does not give you enough tools to properly integrate so I had to slightly compromise the integration of the SVS and the Rythmik to work with the REL. Overall I prefer the Rythmik, but I would move up at least one model size larger if not two, in order to compensate for the lower output power.
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Subs are speakers too! So yeah, there are certainly differences between them. I auditioned several, well known accepted audiophile brands and chose which sounded best to me. Different ones may also have different features as well, so there's that too.
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audiorusty- Good analysis and I agree. Although my favorite subs are Rythmik, Vandersteen and JL Audio
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@mijostyn
I wish I could find the link but is slow mo’s an 18" woofer under a strobe actually wobbling under light power. One side starts moving before the other and goes downhill from there. The excursions are not very far.
I know they wouldn’t make badass, neodymium magnet-fitted 21" pro woofers if wobbling/cone flex was an issue. What’d be an issue for them wouldn’t necessarily be one for us; let’s remember our domestic roofs would fly off over our heads if we where to test such driver at Xvar values, so it’s a practical non-issue with plenty of headroom even. These are very efficient, stiffly suspended drivers that can take from ~1.7kW on up, many of them tested at their limits in horn iterations firing into a compression chamber with uneven pressurization on the cone and huge cone stress to follow, and they eat it up.
I’m sure some drivers can driven to cone flex, but some aren’t all, and at what excursions?
I feel the most comfortable with 12" drivers and you can get to the same place by using multiples. I keep doubling the number until I get what I want. Next stop is 8.
Multiple 12’s can sound great for sure. And for your home setup you mean 8 per channel, right? I was under the impression you’ve implemented 4 per channel already.
I saw Marcus Miller and Mike Stern at the Blue Note in NYC last month and I could feel Marcus’s E string vibrate. It is that kind of authority I would like to get at home. I have great bass, just not that great. I know there are some recordings that can do it like Supertramp’s Crime of the Century or any number of Dave Holland Albums and Jaco albums not to mention Organ works.
Practically speaking I don’t believe you can really overdo bass capacity, unless the sheer volume of cabinetry becomes obtrusive acoustically. Actually, the problem is the other way ’round; the cleaner and more effortless the bass (via more displacement and efficiency) the more it can be enjoyed at proper levels in relation to the remaining audio spectrum - that’s is: you’d gain it "hotter" instead of, perhaps paradoxically, dampening poorer and more meager capacity bass performance.
Some of the vital impact of bass is diminished with central bass nulls (or suck-out) and softer floor constructions that can absorb quite a lot a of bass. In your case a column bass solution would be very appealing.
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@lalitk --
... No disrespect to DIY’s community, but every DIY bloke thinks whatever ‘they’ can do, I can do it better. And please define better, what’s better or best to you or your fellow could easily be ‘good enough’ in someone else eyes. As humans we often tend to judge things based on our personal experiences and express opinions driven by our personal biases :-)
In relation to subs in particular the DIY community can have their cake and eat it too. By that I mean there're no physical restrictions other than what they impose on themselves, every design principle can be pursued - of which detailed plans are oftentimes shared for free, and the cost of assembly and parts is more manageable compared to commercial offerings - certainly with bigger subs. You can yell it to their faces all day long trying to convince them otherwise, but many if not most audiophiles would rather pay dearly for a smaller commercial package than letting size have its say via DIY (at less dough). If you ask me it's an audiophile "attitude" for main speakers that's extended, so to speak, into the sub octaves for how to realize that frequency span as well: with size restrictions (that mostly leaves you with sealed designs) and a particular attention to detail that strikes me as being more about brand identification than core physics.
So, with the lowest ~3 octaves it IS about what DIY offerings can do that commercial products can't, because size gets in the way, and to my mind that's an awfully restricted playground - expensive at that - to limit yourself to.
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@phusis
May I remind you that this thread is about seeking differences between commercially build subwoofers. If you and @mijostyn wish to further portray the superiority of DIY designs then I suggest you start a new thread. Thank you for your consideration and understanding.
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@lalitk , what we are talking about applies to any subwoofer and describes characteristics that others can use to evaluate commercial subs.
@Phusis, Right now it is two per channel and going to 4 drivers in two cabinets for a total of 8. All the drivers are set to form a linear array so they all work as a unit as most bass is center channel. They are however hooked up stereo because I cross up at 100 Hz. As for overdoing it the limiting factor is space. I would use 15" drivers but the enclosures would have to be so big it would be impossible to fit them in.
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@mijostyn
I appreciate your insight and thanks for sharing. One can always contribute here objectively without showcasing their own prejudice or hatred for commercial builds.
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@lalitk , it in not prejudice or hatred , just an analysis of the problem of making subwoofers you can distribute and sell in this market. Pitifully few of us are going to spend $36K per sub on Magicos. Being cost effective and competitive means compromises a DYIer does not have to make. There are all sorts of drivers available for reasonable money. The problem is the enclosure. As an example most woofers are constructed with an MDF base in a box format. Cabinet grade plywood is twice as stiff but 4 times as expensive. A box is perhaps the worst shape to use for a subwoofer enclosure and a lot of bracing has to be done to get resonances above the frequency range of the woofer but these resonances can still be excited. The perfect enclosure would be a sphere as it is self supporting. Try crushing an egg cupping it in both hands applying even pressure. Unfortunately spheres are very difficult to make and work with. Next is a cylinder. It would be much stiffer than a box and could be machined in aluminum but it would be very expensive. Making it out of wood would require multiple laminations around a form with the seams staggered again a very expensive, labor intensive process. It might be cheaper to machine it in aluminum! There are other more complex forms that could be used such a Decadron cylinder.
As far as integrating subs into a system is concerned the same factors apply to all subwoofers. Many commercial subs Like some of the JL Audio units have room control and adjustable delays which is great but you have to adjust the delay by ear a very difficult way to do it but a $300 measurement microphone would cure that problem. A dedicated 2 way crossover is for all intent and purposes mandatory if you want the best performance. IMHO and that of many others using a low pass filter on the sub and crossing it in under the main speaker is a half baked at best solution.
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@lalitk --
May I remind you that this thread is about seeking differences between commercially build subwoofers. If you and @mijostyn wish to further portray the superiority of DIY designs then I suggest you start a new thread. Thank you for your consideration and understanding.
... One can always contribute here objectively without showcasing their own prejudice or hatred for commercial builds.
As I said, "If you ask me" and "to my mind" - these are merely my assessments, and I'm in my right to express them. Instead of conveniently asking a few guys to enter elsewhere because what they're saying rubs you the wrong way, not to mention that you feel the need to act like an admin, why not address the matter without throwing "prejudice" and "hatred" into someone's shoes?
'Objectively' is certainly not off-base when the emphasize is physics more than brands, hence why speaking of the design aspect (or their variations) - whether it's DIY or commercial - is a primary focus that implicitly connects to what the OP is inquiring about.
@mijostyn --
Right now it is two per channel and going to 4 drivers in two cabinets for a total of 8. All the drivers are set to form a linear array so they all work as a unit as most bass is center channel. They are however hooked up stereo because I cross up at 100 Hz. As for overdoing it the limiting factor is space. I would use 15" drivers but the enclosures would have to be so big it would be impossible to fit them in.
Makes sense. Doubling the capacity from 4 to 8 units should see worthwhile results, not least also forming a linear array this way. Is avoiding the traditional approach of DBA distributing the subs throughout the listening space due to the higher cross-over frequency?
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@phusis
I see no sense in arguing with you further, nothing good is going to come out of it. Remember it was you who engaged me, it was you who felt the need to advocate and pitch the superiority of DIY designs. I couldn’t care less or more, cause I already expressed where I stand when it comes to commercial vs DIY subs. Next time you chose to engage someone here or another forum, learning first what they have posted and their beliefs will help you save time and embarrassment. It’s also called ‘knowing your audience’ which involves identifying the audience and adapting a speech to their interests, level of understanding, attitudes, and beliefs.
How far do you think I’m going to succeed by pitching an idea of DIY cables to a guy who has a full loom of Nordost Odin or Synergistic Research SRX?
My suggestion to start your own thread was based on your posts here and after reading your system bio. I knew exactly which camp you belong to and I respect your chosen path. It’s time that you open your mind to the fact that not everyone out there is inclined to build their own subs. Some of us are just happy with our choice of commercially build subs, irrespective of brand and price of admission.
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Ryder, what kind of speakers are those. They must cost a fortune. What are you driving them with?
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Hi OP, I have a small SVS SB1000 PRO and a REL S2. The SVS is, in my system, superior. The REL is more expensive and this reinforces my opinion that RELs are overpriced and overrated and they are certainly not unique in accepting high-level input. REL's oft quoted ability to take on the sound of the main amp would require a sub amp that is completely without colouration, totally neutral and zero distortion, in other words: a wire with gain. There are many disagreements on these forums but all will acknowledge that such an amp as I have just described does not exist.
The S2 is also country specific meaning it is not dual voltage. I emailed REL about this and received a prompt and polite reply. "It will need to go back to the factory for a new amp" Apparently the newer models now address this issue. The phase can only be swapped 180 degrees which makes finding the best place more difficult.
The SVS has continuously variable phase and this together with volume, XO frequency and slope, also presets for movies or music and a band of PEQ with adjustable Q, all remotely done from your listening position via cell phone.
My ongoing house repairs precluded me from building the subs I wanted which are the servo units from Rhythmic/GR Research.
Ignore the joker who claims ported is better than sealed, he has that bass ackwards.
To the poster claiming 4 subs will fix all room problems, they will not. What they do is smooth out the nodes rendering the peaks less severe and filling in the nulls providing a very much improved top to bottom performance and I am a strong proponent of multi-subs..but..what about the time it takes for the sound to decay? To manage the decay time room treatment is necessary, there is no workaround and EQ can't help.
If you treat the room and employ at least 2 subs or 3 or 4 you will realise optimum performance at a level you probably did not know was possible.
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@phusis , You bet. I have two issues crossing at 100 Hz. The subwoofers have to be in stereo and symmetrically arranged around the main speakers and to inhibit room interaction and match the main speaker radiation pattern they have to form a linear array that extends down to 5 Hz. Because there are 4 subs technically they do form a DBA, just with additional characteristics by design to match the main speakers.
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To answer the OP's question very literally, there is one sub which is VERY different from ALL other subs: The Servo-Feedback OB/Dipole Subwoofer, a joint effort between Danny Richie of GR Research and Brian Ding of Rythmik Audio.
Different how, you ask?
Two or three (your choice) 12" woofers optimized for open baffle application, mounted in an open baffle/dipole H-frame. The woofers are powered by the Rythmik A370 plate amp, which includes Rythmik's patended servo-feedback design for woofer control. Added to the stock A370 when used in this OB/Dipole Sub, Brian Ding adds a dipole cancellation-compensation circuit.
If that description does not pique your curiosity, I don't know what would. ;-)
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@lalitk --
I see no sense in arguing with you further, nothing good is going to come out of it.
Except..
Remember it was you who engaged me, it was you who felt the need to advocate and pitch the superiority of DIY designs.
No, I didn’t engage you; I challenged/called out the general standings of commercial subs as being limited to mostly smaller, lower efficiency sealed designs, hereby forgoing a breadth of larger and more efficient design variations that more readily accommodates physics and, in effect, performance - unless a multitude of sealed subs with larger drivers (12" on up) are used. Surely I didn’t need to know the specifics of you and your setup to allow myself to engage in that subject? But now that you mention it I did look up your system, and it looks (and I’m sure sounds) beautiful - truly.
I couldn’t care less or more, cause I already expressed where I stand when it comes to commercial vs DIY subs. Next time you chose to engage someone here or another forum, learning first what they have posted and their beliefs will help you save time and embarrassment. It’s also called ’knowing your audience’ which involves identifying the audience and adapting a speech to their interests, level of understanding, attitudes, and beliefs.
How far do you think I’m going to succeed by pitching an idea of DIY cables to a guy who has a full loom of Nordost Odin or Synergistic Research SRX?
As per my paragraph just above. You’re pulling an ad hominem here, so let’s leave it at that.
My suggestion to start your own thread was based on your posts here and after reading your system bio. I knew exactly which camp you belong to and I respect your chosen path. It’s time that you open your mind to the fact that not everyone out there is inclined to build their own subs. Some of us are just happy with our choice of commercially build subs, irrespective of brand and price of admission.
As most who post here don’t go DIY with their subs implementation it seems to me trying to counter the commercial majority with a minority DIY approach for core physics-reasons outlined earlier isn’t uncalled for. You yourself called for "objectivity" in this discussion, and following an analysis (not least with poster @mijostyn's contributions) of design variations, overall implementation with the use of DSP tools in addition to build rigidity strikes me as accommodating just that. I hope focusing on these aspects tells one a thing or two about or puts into perspective to which degree (i.e.: relatively little) commercial sub brands may differ sonically, or at least that’s my assessment.
I know full well many if not most go the commercial route with subs, and I respect that - your choices as well, obviously. I’ve been there myself, done that. Not saying I drew out the most of its potential, but only so many iterations needed to convince me to search elsewhere, go active, include a separate DSP, high-pass the mains and a DIY route with subs to include design options practically not found in commercial offerings. And that’s that. Thanks for your time.
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@phusis
Water under the bridge, let’s move on and be happy with our choices and the chosen path to enjoy music.
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I have a different set of criteria than you. First is design and I like the servo design, and the brand that uses that design is Rythmik. There may be others, not sure. Secondly, I like integration as either easy or hard. I think SVS has an app that I have heard some people like and state it works, I have not tried it. Rythmik and REL have multiple ways to adjust levels to allow the sub to match my stereo and high level/ low level connection options. Third and and not necessarily in order is - does the company have a good reputation as a whole and are they know for making subs for the application your looking for ie Home Theatre, Stereo, etc. Fourth, and this is a BIG one, how is the reputation for service and build quality. If the sub is designed well, sounds great, but the brand does not care much about fixing the sub down the road, and would rather you buy another from them... I don’t buy from that company. I have had good luck with Rythmik, but I may try either REL or another brand down the road, maybe even Vandersteen. I wouldn’t buy SVS.
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