alexclaber Posted December 8, 2009 Share Posted December 8, 2009 I think it's time to start a movement for cab manufacturers to explicitly state the volume displacement (Vd) of their cabs. Everywhere I look I see headline power figures (oooh, 1000W, wow!) which are totally unrealistic given that we play bass and every bassist knows that playing bass involves moving air. Yes, so much of the tone is actually in the midrange but the feel of the bass requires air to be moved, and if a cab can't move sufficient air then its tone in the mids and highs will degenerate as you turn it up. So here's the numbers for my cabs (note that if comparing to a sealed cab you should halve the Vd of the sealed cab or double it for the ported cab because a correctly tuned port effectively doubles Vd). Midget = 330cc Compact = 505cc D.M. = 660cc Big One = 846cc Vintage = 1010cc It isn't a hard number to find out - it's simply the cone area multiplied by the cone excursion - on datasheets cone area is Sd (or D x D x Pi / 4) and clean cone excursion is Xmax. Xmax can be worked out three ways - ( voice coil length minus gap height ) divided by two (which is a bit too conservative), (voice coil length minus gap height)/two plus (gap height / 4), or by measuring the excursion at which THD reaches 10%. Celestion use the first method so a neo 10" with a 2mm Xmax could be recalculated more fairly as (Hc - Hg)/2 + Hg/4 = (12 - 8)/2 + 8/4 = 4mm, not dissimilar to an Eminence neo 10" with a 4.2mm Xmax. So a 4x10" with Celestion neo 10"s would come in at 554cc whilst one with Eminence neo 10"s would come in as 581cc. Typically non-neo speakers in the bass guitar world have lower Xmax, though there are a select few exceptions. If you're looking at buying a cab and want to know how loud it can really play, ask what the Vd is. Alex P.S. Yes there are times when a cab with tons of Vd won't be loud because it has insufficient midrange sensitivity and thermal power handling, but the vast majority of cabs on the market have plenty of both of those, Vd is the predominant deficiency. Link to comment Share on other sites More sharing options...
Born 2B Mild Posted December 8, 2009 Share Posted December 8, 2009 So out of interest, can you list the Vd for a few well known cabs that might be thought of as rivals for the Barefaced dollar? e'g. GS112s, Bergantino, Schroeder, EBS, Epifani etc? Link to comment Share on other sites More sharing options...
alexclaber Posted December 8, 2009 Author Share Posted December 8, 2009 [quote name='Born 2B Mild' post='678099' date='Dec 8 2009, 04:15 PM']So out of interest, can you list the Vd for a few well known cabs that might be thought of as rivals for the Barefaced dollar? e'g. GS112s, Bergantino, Schroeder, EBS, Epifani etc?[/quote] The problem with doing that is everyone that owns those cabs goes and gets all offended and huffy and then I get vilified and accused of saying their gear is crap (which I never am, I'm just providing some perspective and tools to help quantity people's experiences) - I'd rather the manufacturers themselves stood up and told the truth. Alex Link to comment Share on other sites More sharing options...
Wolverinebass Posted December 8, 2009 Share Posted December 8, 2009 Yeah, go on!! Name and shame Alex!! In all seriousness though, I'd be very interested to know this stuff. I should probably add myself to the Compact circulation list as I'd be very intrigued to see how the compact sounds in comparison to Markbass cabs I've got. Link to comment Share on other sites More sharing options...
bigjohn Posted December 8, 2009 Share Posted December 8, 2009 (edited) I'd be interested to know if my new cab has got lots of Vd or not... Spill the beans! Edited December 8, 2009 by bigjohn Link to comment Share on other sites More sharing options...
alexclaber Posted December 9, 2009 Author Share Posted December 9, 2009 Seriously, if you want to know the answers then email the manufacturers directly and ask them! And feel free to post their responses. One thing I will say is that there are no OEM models which are vastly different to stock drivers when it comes to the motor system and it's the motor which determines Xmax. Alex Link to comment Share on other sites More sharing options...
Protium Posted December 9, 2009 Share Posted December 9, 2009 [quote name='Born 2B Mild' post='678099' date='Dec 8 2009, 04:15 PM']So out of interest, can you list the Vd for a few well known cabs that might be thought of as rivals for the Barefaced dollar? e'g. GS112s, Bergantino, Schroeder, EBS, Epifani etc?[/quote] The Schroeder 1212L (with eminence deltalite speakers) = 510cc. For any cabs using eminence speakers you can find the data here: [url="http://www.eminence.com/resources/params.asp"]http://www.eminence.com/resources/params.asp[/url] Link to comment Share on other sites More sharing options...
EBS_freak Posted December 9, 2009 Share Posted December 9, 2009 Whats with all the science? What's wrong with auditioning cabs by using your ears? At the end of the day, that is what you are going to be hearing your cabs with. You should take the following into account. Tone - does the cab make your gear sound pleasant to your ears? Volume - is it loud enough for your needs? Portability/Weight - is it going to be a nightmare to get to gigs? Looks - do you like the look of your gear or does it make you wince every time you look at it? Compatability - is the cab suited to work with your gear e.g. does the impedance of the cab and amp match? Specs on paper mean nothing. Performance in the real world means everything. Link to comment Share on other sites More sharing options...
crez5150 Posted December 9, 2009 Share Posted December 9, 2009 [quote name='EBS_freak' post='678919' date='Dec 9 2009, 11:32 AM']Whats with all the science? What's wrong with auditioning cabs by using your ears? At the end of the day, that is what you are going to be hearing your cabs with. You should take the following into account. Tone - does the cab make your gear sound pleasant to your ears? Volume - is it loud enough for your needs? Portability/Weight - is it going to be a nightmare to get to gigs? Looks - do you like the look of your gear or does it make you wince every time you look at it? Compatability - is the cab suited to work with your gear e.g. does the impedance of the cab and amp match? Specs on paper mean nothing. Performance in the real world means everything.[/quote] +1 Link to comment Share on other sites More sharing options...
razze06 Posted December 9, 2009 Share Posted December 9, 2009 [quote name='EBS_freak' post='678919' date='Dec 9 2009, 11:32 AM']Whats with all the science? What's wrong with auditioning cabs by using your ears? At the end of the day, that is what you are going to be hearing your cabs with. You should take the following into account. Tone - does the cab make your gear sound pleasant to your ears? Volume - is it loud enough for your needs? Portability/Weight - is it going to be a nightmare to get to gigs? Looks - do you like the look of your gear or does it make you wince every time you look at it? Compatability - is the cab suited to work with your gear e.g. does the impedance of the cab and amp match? Specs on paper mean nothing. Performance in the real world means everything.[/quote] All true, but without science and facts you will not get advancements in the technology that produces the sounds you are auditioning with your ears and reduces the weight of your rig. Link to comment Share on other sites More sharing options...
Merton Posted December 9, 2009 Share Posted December 9, 2009 [quote name='EBS_freak' post='678919' date='Dec 9 2009, 11:32 AM']Tone - does the cab make your gear sound pleasant to your ears? Volume - is it loud enough for your needs?[/quote] I agree with your sentiment, but thwe above two points are directly infuenced by Vd, especially voume, so these specs do matter and make a lot more sense than the power handling figure most manufacturers give. Link to comment Share on other sites More sharing options...
razze06 Posted December 9, 2009 Share Posted December 9, 2009 [quote]All true, but without science and facts you will not get advancements in the technology that produces the sounds you are auditioning with your ears and reduces the weight of your rig. [quote name='EBS_freak' post='678953' date='Dec 9 2009, 12:06 PM'] But do you, as the end user, care? For example, for any cab, if the specs look great but the cabs sound sh*te, would you still buy them?![/quote][/quote] Will the appearance of more specs on the datasheet alter the quality of the sound that comes out of the speaker? Link to comment Share on other sites More sharing options...
bigjohn Posted December 9, 2009 Share Posted December 9, 2009 The science does make a bit of difference to the end user in terms of choosing a cab in the first place though. After all, how many of us have trialled a cab in gig situation before buying? Link to comment Share on other sites More sharing options...
51m0n Posted December 9, 2009 Share Posted December 9, 2009 [quote name='razze06' post='679015' date='Dec 9 2009, 01:03 PM']Will the appearance of more specs on the datasheet alter the quality of the sound that comes out of the speaker?[/quote] No, but they will alter your ability to judge a cab as worthy or not of even bothering to test given the application for which you are going to buy it though. How many times have I heard on this forum that all that counts is the sound on the gig? Why is that such a huge issue compared to turning up loud in the shop? Why can you not have any idea how well a cab will perform on the gig given the tone in the shop? Part of this is because you cant even guess given the specs that are published. Alex is trying to get widespread demand for proper useful specs to be published that will definitely enable and empower you the end user. Why are any of you fighting that? What is the problem? No one is suggesting that you dont need to go and hear a cab because of this spec. All that is being suggested is that a given cab with this spec should produce a similar real world volume to another cab with this spec the same as it. That is what the much hated watts RMS is supposed or purported to do now, but doesnt. It doesnt mean you will like the sound, just that there should be x amount of sound possible from the cab. Or am I very much mistaken Alex? Link to comment Share on other sites More sharing options...
mildmanofrock Posted December 9, 2009 Share Posted December 9, 2009 (edited) [quote name='EBS_freak' post='678953' date='Dec 9 2009, 12:06 PM']But do you, as the end user, care? For example, for any cab, if the specs look great but the cabs sound sh*te, would you still buy them?![/quote] But all or most cab companies provide specifications anyway. Of course, it's vital to hear a cab working - no one here is saying you shouldn't. But accurate technical facts don't do any harm. And people obviously care about the technical aspects or they wouldn't put them in their marketing. So why not add Volume Displacement figures to the list of specs? Would you buy a 100 grand car on just the strength of a test drive? Maybe. But I bet you'd be interested in seeing the specifications too. Edited December 9, 2009 by mildmanofrock Link to comment Share on other sites More sharing options...
mildmanofrock Posted December 9, 2009 Share Posted December 9, 2009 (edited) [quote name='EBS_freak' post='679045' date='Dec 9 2009, 01:37 PM']Only those that are blind and/or deaf would purchase based on spec.[/quote] Of course. I don't think Alex or anyone is suggesting otherwise. But if specs are already out there, I don't think there's anything wrong with adding another spec to the list. 51mOn is right. There's nothing wrong with arming people with quality facts to help them make informed buying decisions. Read the specifications, but don't forget to use your ears. Edited December 9, 2009 by mildmanofrock Link to comment Share on other sites More sharing options...
bigjohn Posted December 9, 2009 Share Posted December 9, 2009 [quote name='Protium' post='678908' date='Dec 9 2009, 11:22 AM']The Schroeder 1212L (with eminence deltalite speakers) = 510cc.[/quote] Is that good or bad? Would that change dramatically with the celestion loaded 1212L? Link to comment Share on other sites More sharing options...
51m0n Posted December 9, 2009 Share Posted December 9, 2009 [quote name='EBS_freak' post='679045' date='Dec 9 2009, 01:37 PM']Only those that are blind and/or deaf would purchase based on spec. [b]Look at the cars that go around the Top Gear track. Proof that spec means nothing compared to real world performance. [/b] There has been much discussion at finnbass and the real world tests of cabs show that sometimes, the specs really are insignificant to how cabs perform against others.[/quote] Err no, thats proof that that driver on that day could go round that fast if you believe that show..... If you put a faster driver in the car they may go quicker depending on a load of other factors that I cant be bothered to go through (see the proggie with Lewis making everyone else look like a numpty in the reasonably priced car in the wet), even the same driver on a different day almost certainly will prove to you a different level of performance from the same car. Specs are just that, specifications, they (should) have tolerances with them (or they are effectively meaningless), they must be independantly verified and verifiable or they are not trustworthy. They must specify the correct variables or they are actually obfuscation tactics used as often as not by marketing (see watts rms). Given proper specs it is possible to make very well informed decisions. Without hearing a cab though, even the most technical amongst us would not know for sure exactly how it sounded - and I mean tonally here - as opposed to "a.n.other" cab. We would know its frequency response at different volumes and angles from the speaker, the thermal and mechanical abilities of the cab wrt to its sound production and dispersal, and therefore be able to form a really good opinion as to whether this cab could possibly play Wembley and fit in the back of a Micra, when your Roadie has a very very bad back. Even armed with this info you cannot be absolutely sure how it sounds to you. But if you could tell all that for sure then all you would need to know is, "do I like how it sounds", unfortunately at the moment, even if you like how it sounds, you cant tell if thats how it sounds on the gigs you play, or if its vomiting forth its voice coil before your guitard has hit the third chorus. Link to comment Share on other sites More sharing options...
razze06 Posted December 9, 2009 Share Posted December 9, 2009 [quote name='51m0n' post='679023' date='Dec 9 2009, 01:11 PM']No, but they will alter your ability to judge a cab as worthy or not of even bothering to test given the application for which you are going to buy it though. How many times have I heard on this forum that all that counts is the sound on the gig? Why is that such a huge issue compared to turning up loud in the shop? Why can you not have any idea how well a cab will perform on the gig given the tone in the shop? Part of this is because you cant even guess given the specs that are published. Alex is trying to get widespread demand for proper useful specs to be published that will definitely enable and empower you the end user. Why are any of you fighting that? What is the problem? No one is suggesting that you dont need to go and hear a cab because of this spec. All that is being suggested is that a given cab with this spec should produce a similar real world volume to another cab with this spec the same as it. That is what the much hated watts RMS is supposed or purported to do now, but doesnt. It doesnt mean you will like the sound, just that there should be x amount of sound possible from the cab. Or am I very much mistaken Alex?[/quote] I am actually in agreement with you. I was advocating the addition of further useful specs to the datasheet, to corroborate what you hear when you try it. Maybe I didn't phrase it the best possible way... Link to comment Share on other sites More sharing options...
wateroftyne Posted December 9, 2009 Share Posted December 9, 2009 What's wrong being being armed with all the facts? Nowt. That's what. Good on you, Alex. And, until the day comes when it's the norm for shops / cab builders to lend cabs out so we can try 'em in the real world*, we're stuck with how they sound in the shop. Which is a waste of time. [size=1]*Thanks to Alex for pioneering this service, too...[/size] Link to comment Share on other sites More sharing options...
Protium Posted December 9, 2009 Share Posted December 9, 2009 [quote name='EBS_freak' post='678919' date='Dec 9 2009, 11:32 AM']Specs on paper mean nothing. Performance in the real world means everything.[/quote] Yeah, I'm gona go to a shop to test out the weight of a cab because '30kg' on paper means nothing Link to comment Share on other sites More sharing options...
EBS_freak Posted December 9, 2009 Share Posted December 9, 2009 [quote name='51m0n' post='679079' date='Dec 9 2009, 02:13 PM']Err no, thats proof that that driver on that day could go round that fast if you believe that show.....[/quote] And your playing one day can differ to the next... I'm with Bose on this one. Dont publish meaningless specs that can be interpretted in different ways. Let your ears do the deciding. Link to comment Share on other sites More sharing options...
EBS_freak Posted December 9, 2009 Share Posted December 9, 2009 [quote name='wateroftyne' post='679096' date='Dec 9 2009, 02:27 PM']And, until the day comes when it's the norm for shops / cab builders to lend cabs out so we can try 'em in the real world*, we're stuck with how they sound in the shop. Which is a waste of time. [size=1]*Thanks to Alex for pioneering this service, too...[/size][/quote] Bang on. That is a big plus. At least people are hearing the cabs for real. The only problem is, for many retailers this wouldn't work because the system would be open to abuse. Need a cab for a gig? Then lend a cab out for a test... A shame really. Link to comment Share on other sites More sharing options...
Stylon Pilson Posted December 9, 2009 Share Posted December 9, 2009 (edited) When you buy a car, you want to know, among other things, what fuel consumption it will get. S.P. Edited December 9, 2009 by Stylon Pilson Link to comment Share on other sites More sharing options...
EBS_freak Posted December 9, 2009 Share Posted December 9, 2009 [quote name='Stylon Pilson' post='679132' date='Dec 9 2009, 03:00 PM']When you buy a car, you want to know, among other things, what fuel consumption it will get. S.P.[/quote] And we all know that the published fuel consumption is a load of BS. Link to comment Share on other sites More sharing options...
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