alexclaber Posted February 9, 2011 Share Posted February 9, 2011 Phil's explanation is correct but it's easily misunderstood because it's referring to ALL loudspeakers. If you look at the small subset that represent bass guitar drivers then there's plenty of room for 8"s to go lower than 15"s and 12"s to have more mids than 10"s. Look at SWR - their Henry the 8x8 is well renowned for having more bottom than all their cabs bar possibly the Big Ben. Ampeg - the 410HLF has easily the deepest lows out of everything they produce. Acme - lowest response on any cab on the market and they use 10"s, and now a 12". Barefaced - 12" Big Baby goes way lower than 15" Compact. Bergantino - HT210 has deeper lows and less mids than HT115. Eden - 210XST has more bottom and less midrange than 115XL. A more consistent thing is that any conventional cab (i.e. woofer only or woofer plus tweeter) which has particularly deep fat lows is likely to be subdued in the midrange. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted February 9, 2011 Share Posted February 9, 2011 [quote name='alexclaber' post='1121592' date='Feb 9 2011, 12:19 PM']Phil's explanation is correct but it's easily misunderstood because it's referring to ALL loudspeakers. If you look at the small subset that represent bass guitar drivers then there's plenty of room for 8"s to go lower than 15"s and 12"s to have more mids than 10"s.[/quote] True. The fact of the matter is that drivers created for use in electric bass speakers have similar specs, because they're all intended to work within the same bandwidth. And that being the case there's very little difference between them in how they function where performance is dictated by the specs. Dispersion is the exception, as dispersion isn't dictated by specs, it's dictated by the dimension of the radiating plane. Quote Link to comment Share on other sites More sharing options...
Phil-osopher10 Posted February 9, 2011 Author Share Posted February 9, 2011 So let's bring this down to a commercial level, Specs have no 'real' affect on how it sounds in terms of tone? They can tell you how loud it goes? Is that why alex, you give the one month return period? Possible rant Also why do many manufactures have so many different spec listings? Shouldn't there be a unified code of specs that the manufacturer has to produce? I realise that tone is personal. But as a consumer, I feel with local music store shutting up shop and internet shopping taking over, I personally think that without unifying a spec sheet as to how things are done that it is very hard to make a calculated choice. As trial and error can be expensive. Rant over Quote Link to comment Share on other sites More sharing options...
xgsjx Posted February 9, 2011 Share Posted February 9, 2011 Most manufacturers are only going to give you specs that they think will sell the product, not what it's actually gonna sound like. I can't see Carlsbro putting "has the characteristics of the last three hobnobs being shaken in the tin". Quote Link to comment Share on other sites More sharing options...
Phil-osopher10 Posted February 9, 2011 Author Share Posted February 9, 2011 That I understand. It just frustrates me. A lot. Excuse the rant, I feel bad now. Quote Link to comment Share on other sites More sharing options...
chris_b Posted February 9, 2011 Share Posted February 9, 2011 [quote name='Phil-osopher10' post='1121919' date='Feb 9 2011, 09:18 PM']....That I understand. It just frustrates me. A lot. Excuse the rant, I feel bad now....[/quote] Why? There are a lot of great sounding speaker cabs out there. Just find one you like. It doesn't matter what the specs say.... what do your ears tell you? Quote Link to comment Share on other sites More sharing options...
Mr.T Posted February 9, 2011 Share Posted February 9, 2011 I can get the sound I want out of my cabs. Nuff said? Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted February 10, 2011 Share Posted February 10, 2011 (edited) Maybe it is because I used to teach science but I worry about over-simplification intended to clarify explanations for non-technical people because it leads to the spreading of ideas which are false, particularly since the salesmen and advertisers are only too willing to exploit any such myths. There aren't any truths about all 15's or all 10's, even the beaming isn't true because as Alex has explained the cone is flexing at higher frequencies so the radiation is effectively from a reduced area. (That in itself is a simplification) However there are things that are easier to do with big speakers and small ones and if you go through, say, the Eminence catalogue you will see that on average their 15's are more efficient go deeper and have poorer hi frequencies than their 10's. Both this and the fact that there are exceptions to this general tendency are easily explicable with the physics that a lot of us know. A lot of modern designs are concentrating on the holy grail of deep bass with portability. Smaller cabs are easier to carry for musicians and easier for shops and distributors. Smaller cabs ultimately need to use smaller speakers (although not all small speakers need smaller cabs). Smaller speakers are also generally lighter. It has never been true that there is a sound of a 15 or a 10 and small speakers can be made to go low by simply adding weight to the cone and using a softer suspension, no different to a bass string really. Adding weight to the cone will generally make it more rigid and this will increase the area in which the speaker acts as a piston and will subdue the midrange. Making it heavier will make it harder to accelerate reducing the top end further and will also reduce its efficiency. That is why this happens [quote name='alexclaber' post='1121592' date='Feb 9 2011, 05:19 PM']A more consistent thing is that any conventional cab (i.e. woofer only or woofer plus tweeter) which has particularly deep fat lows is likely to be subdued in the midrange.[/quote] Designers make trade offs and then look at ways of compensating for the effects. Better magnets, more power handling, longer excursion limits, shaped frequency responses can all be used to restore some of what has been lost by using a smaller speaker and you can also use multiple units, but that comes at its own costs. Equally someone using a single 15 in a design can compensate for the shortcomings inherent in this pathway to squeeze extra mids and reduce beaming. This is pretty much what the Barefaced Compact represents for example, a good set of compromises using modern speaker technology to achieve a particular design aim. I suppose what I want is for people to be aware of the idea of speaker designs all being compromises, and that they can't have everything in a single solution. If someone promises everything in a simple tiny box they aren't being honest. There isn't any magic either, good engineering and the laws of physics can explain what a design does and how it does it. In the end musicians have to trust their ears and if a design works for you that is good, the designer has made the compromises that suit you. Don't close your mind to new designs without hearing them but don't believe all the hype either. Edited February 10, 2011 by Phil Starr Quote Link to comment Share on other sites More sharing options...
JTUK Posted February 10, 2011 Share Posted February 10, 2011 [quote name='chris_b' post='1122016' date='Feb 9 2011, 10:36 PM']There are a lot of great sounding speaker cabs out there. Just find one you like. It doesn't matter what the specs say.... what do your ears tell you?[/quote] This... Just get in your mind a few cabs that you like the look of and then try and get to hear them, The rest of the stuff can be useless twitter by and large. Quote Link to comment Share on other sites More sharing options...
Conan Posted February 10, 2011 Share Posted February 10, 2011 [quote name='Phil Starr' post='1122318' date='Feb 10 2011, 08:56 AM']In the end musicians have to trust their ears and if a design works for you that is good, the designer has made the compromises that suit you. Don't close your mind to new designs without hearing them but don't believe all the hype either.[/quote] Spot on! Quote Link to comment Share on other sites More sharing options...
LawrenceH Posted February 10, 2011 Share Posted February 10, 2011 [quote name='JTUK' post='1122460' date='Feb 10 2011, 11:42 AM']This... Just get in your mind a few cabs that you like the look of and then try and [b]get to hear them,[/b]*[/quote] * at true gigging volume. That is where a huge number of design issues will make themselves apparent, and a 10" monster (oo-er) can reveal itself to be nothing but a bedroom perfomer (oo-er again) as it runs out of excursion and overloads its inadequately sized ports. Phil's post is an excellent qualitative description, very useful for bridging the gap between small signal parameters in the abstract and how they might be manipulated by different driver design decisions in the 'real world'. It's a good basic lesson for those of us who have a habit of poring over driver spec data seeking the elusive (non-existent) 'perfect' driver Quote Link to comment Share on other sites More sharing options...
Phil-osopher10 Posted February 10, 2011 Author Share Posted February 10, 2011 I must apologise for my annoyance last night. I hope no offence was taken. Those are some good points I must admit, I'll just have to try a lot of cabs before I buy. Quote Link to comment Share on other sites More sharing options...
Conan Posted February 10, 2011 Share Posted February 10, 2011 [quote name='Phil-osopher10' post='1121836' date='Feb 9 2011, 07:52 PM']Specs have no 'real' affect on how it sounds in terms of tone?[/quote] I'm with Harry Potter on this one. I [i]like[/i] the Phil-osopher's tone.... Quote Link to comment Share on other sites More sharing options...
alexclaber Posted February 10, 2011 Share Posted February 10, 2011 [quote name='Phil-osopher10' post='1121836' date='Feb 9 2011, 07:52 PM']Specs have no 'real' affect on how it sounds in terms of tone? They can tell you how loud it goes? Is that why alex, you give the one month return period?[/quote] I deal with the tone (and SPL) issue by finding out things like what bass(es) are used, what strings (and how worn in is ideal), what amp(s) is/are used/liked, what they've liked/disliked about their rig and/or other rigs they've used, what music they play, what their band is like, what venues they play, what bass tones they like (I ask for clips or samples, so no risk of words confusing matters) and so on. Quite often people enquire about one model and end up with a different one because their answers to the questions suggest their original choice isn't the best fit. Since adding that questioning method to the process, and becoming more experienced at analysing the answers, we've had very few people want to take advantage of the one month return option, which is nice. Certainly the last thing I want to spend my time doing is shipping cabs around the world in the vague hope that someone might like them - I want to be pretty damned certain that they will! [quote name='janmaat' post='1121238' date='Feb 9 2011, 12:25 PM']after so much talk about speaker diameters - i would really like to hear some more about the dimension of the cab, how that relates to the speakers etc. - and the volume.[/quote] The size of the cab affects two things - the low frequency sensitivity and the dispersion: The bigger the cab, the higher the low frequency sensitivity for a given LF roll-off in the lows - the lower the cab goes, the lower the LF sensitivity for a given size, or to put it another way, if you want a certain LF sensitivity then to go lower you have to make the cab bigger. Simplistically the smaller the cab volume compared to the cone area, the higher the low frequency roll-off will be - you can get around that by using heavier cones but that lowers the LF sensitivity - no free lunch! Hoffman's Iron Law: Sensitive, low, small - pick any two. The horizontal disperson is inversely proportional to the width of the radiating plane - so the greater the total width of the speaker(s), the less consistent the sound will be as you move from side to side across the venue. Quote Link to comment Share on other sites More sharing options...
dincz Posted February 10, 2011 Share Posted February 10, 2011 (edited) [quote name='alexclaber' post='1123020' date='Feb 10 2011, 07:56 PM']The size of the cab affects two things - the low frequency sensitivity and the dispersion[/quote] Is there any way to widen the high frequency dispersion of large drivers by adding some kind of magic reflector (effectively a kind of "audio lens") in front of the cone? Edited February 10, 2011 by dincz Quote Link to comment Share on other sites More sharing options...
alexclaber Posted February 10, 2011 Share Posted February 10, 2011 [quote name='dincz' post='1123066' date='Feb 10 2011, 07:28 PM']Is there any way to widen the high frequency dispersion of large drivers by adding some kind of magic reflector (effectively a kind of "audio lens") in front of the cone?[/quote] Yes but the challenge is to do it without it screwing up the response in general. For guitar cabs, many of which suffer from an icepick in the ear on-axis treble peak, something like a simple 'beam blocker' can work very well. The Midget T's tweeter-mount works a bit like this with the tweeter kicking in to fill the gap. Quote Link to comment Share on other sites More sharing options...
stevie Posted February 10, 2011 Share Posted February 10, 2011 Yes, you could add a horn, preferably with a correctly designed phase plug. An easier and better solution would just be to add a midrange driver. Quote Link to comment Share on other sites More sharing options...
Phil Starr Posted February 10, 2011 Share Posted February 10, 2011 [quote name='dincz' post='1123066' date='Feb 10 2011, 07:28 PM']Is there any way to widen the high frequency dispersion of large drivers by adding some kind of magic reflector (effectively a kind of "audio lens") in front of the cone?[/quote] this used to be quite common with high frequency horns sporting multi finned diffraction gratings and bullet tweeters with diffracting slots. The other pathway is to use a horn to control directivity, though the horn itself will act as a high pass filter and boost the efficiency within its pass band but not below leaving you with a shelved response. Bass horns are too big to be practical. A far better option for bassists is to use a midrange cone in the 4-6" range with a proper crossover to handle the upper octaves. Alex already does this as do several other manufacturers and this is a lot less gimmicky than adding a HF horn. Quote Link to comment Share on other sites More sharing options...
alexclaber Posted February 10, 2011 Share Posted February 10, 2011 Aha! Presumably some of you remember these? 10" or 12" woofer I believe, in a ported bandpass cab (the horizontal slot is the port on the rear enclosure, the vertical slot is the port on the front enclosure). The vertical slot also diffracts the higher frequency output for broader horizontal dispersion. Not a terribly hi-fi way of doing things because you get lots of mids and highs bouncing around the front enclosure and interacting but having used one ages ago it did cut through in a honky sort of way. Quote Link to comment Share on other sites More sharing options...
dincz Posted February 10, 2011 Share Posted February 10, 2011 All very interesting. Thanks for the responses. What would be the easiest and cheapest way to increase the horizontal dispersion of a Compact? Stack another Compact on top? I'm rather hazy about all of this. I realise that vertical stacking reduces the vertical dispersion, but does it also widen horizontal dispersion? That may be a stupid question in that if there's less vertical spread then it has to go somewhere else. Would it be feasible to add a separate 6" or 8" in its own small enclosure with a suitable Xover network? A Barefaced Broad Baby perhaps? Quote Link to comment Share on other sites More sharing options...
Mr. Foxen Posted February 10, 2011 Share Posted February 10, 2011 [url="http://greenboy.us/fEARful/headcase.htm"]There is this which is a mid/treble enclosure.[/url] Not really worth pairing with Compact, better off with a dedicated sub. The Big Twin and other midrange driver cabs fill the need, so no point adding to the compact. Quote Link to comment Share on other sites More sharing options...
franzbassist Posted February 10, 2011 Share Posted February 10, 2011 My PJB rig sounds very different to any other rig I've owned, but I really like it. Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted February 11, 2011 Share Posted February 11, 2011 [quote name='dincz' post='1123204' date='Feb 10 2011, 04:03 PM']I realise that vertical stacking reduces the vertical dispersion, but does it also widen horizontal dispersion?[/quote]It does not[quote]if there's less vertical spread then it has to go somewhere else.[/quote]It does, into the audience. Making the source higher extends further out from the source and further down in frequency the zone of the nearfield condition, where SPL drops at a 3dB per doubling of distance from the source rather than the 6dB of the farfield condition. Going from one cab to two doesn't extend the nearfield all that far, but it does extend it, four times further than with one cab to be precise. Quote Link to comment Share on other sites More sharing options...
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