OzzyGreg Posted April 30, 2011 Posted April 30, 2011 (edited) . Hi guys, I get so frustrated with speaker box design software! I just can't seem to get my head around them properly. I've tried Unibox408 and Boxplot2, online calculators, and get completely different vented box volume figures from each! Based on software reputation, I selected my Unibox figures as gospel and thought I had it nailed, building three 2x10 cabs fitted with [b]new[/b] Etone 1020 speakers. The cabs are to be honest, volume-wise, pathetic. The drivers distort at any volume. I've tried one, two and three of them. Direct out of the amp, linked, everything. The drivers are wired in parallel and the boxes have the recommended ports, sound deadening inside, etc. etc. [attachment=78733:3_x_twin..._box_rig.jpg] The tone is there at lower volumes, but as soon as I try to crank my Peavey MkIII 400 head's volume up above half they distort to buggery! This is regardless of pre and post gain adjustments. I even tried a mate's (other) Peavey bass head and the speakers were still the same. I'm half bald and if I had hair I reckon I'd be tearing it out at the moment! Can anyone who is familiar with speaker design software PULEEEEZE run these figures and see what [b]you[/b] come up with? (I ended up with 65 litres for a twin driver box.) I'm over this! [attachment=78734:etone_1020_specs.jpg] [size=3]Any help/advice is greatly appreciated![/size] Greg Edited April 30, 2011 by OzzyGreg Quote
Mr. Foxen Posted April 30, 2011 Posted April 30, 2011 (edited) There is no Xmax figure there, that is the one that tells you how much power the speakers will take before fartijng out. I suspect it may not be high for these speakers, you want to aim for around 4-6mm. Really need a full set of Thiele-Small parameters for good modelling, as well as a frequency response chart (because modelling doesn't tell you much around the midrange. WinISD Alpha is the recommended program, and the things you need to look for are excursion limited power handling, but I think the default is often the response curve, that will tell you if you cab will sound funny with one watt, but the power handling one will tell you why it is farting out. Edited April 30, 2011 by Mr. Foxen Quote
OzzyGreg Posted May 1, 2011 Author Posted May 1, 2011 Thanks for the response Mr. Foxen. I was given an Xmax figure (via email) of 10mm by Etone believe it or not. (Sorry, I neglected to add that to the table!) I will contact them again and see if they have frequency response chart. Greg [quote name='Mr. Foxen' post='1216253' date='May 1 2011, 12:54 AM']There is no Xmax figure there, that is the one that tells you how much power the speakers will take before fartijng out. I suspect it may not be high for these speakers, you want to aim for around 4-6mm. Really need a full set of Thiele-Small parameters for good modelling, as well as a frequency response chart (because modelling doesn't tell you much around the midrange. WinISD Alpha is the recommended program, and the things you need to look for are excursion limited power handling, but I think the default is often the response curve, that will tell you if you cab will sound funny with one watt, but the power handling one will tell you why it is farting out.[/quote] Quote
Mr. Foxen Posted May 1, 2011 Posted May 1, 2011 Get a full set of Thiele-Small parameters from them, and use that for the modelling, and look at the excursion chart. 10mm Xmax sounds a bit magical. The fancy Neodymium 15" woofers (made for xmax, at the cost of mids and highs) don't have an xmax that high. You could also try lowering your port tuning until they stop farting out, by extending the port, eventually the low end will choke off though. Quote
stevie Posted May 1, 2011 Posted May 1, 2011 I wish people would stop recommending WinISD on here. It's a tool, but like any tool, unless you know what you're trying to achieve with it, it will give you a false sense of security. I don't need WinISD to tell me that the box size is much too big and the drivers are useless for bass guitar. I'm not surprised it sounds rubbish. Sell the drivers and get some proper ones. Sorry if that's not what you want to hear. Incidentally, I doubt very much if your drivers have an xmax of 10mm because they are midrange drivers, which don't need a large xmax. Quote
BB3000S Posted May 1, 2011 Posted May 1, 2011 [quote name='OzzyGreg' post='1216237' date='May 1 2011, 01:24 AM'][attachment=78734:etone_1020_specs.jpg] [size=3]Any help/advice is greatly appreciated![/size] Greg[/quote] F0 = 70Hz is too high for bass, as been said that's more the lower level for a midrange driver. Quote
Mr. Foxen Posted May 1, 2011 Posted May 1, 2011 [quote name='stevie' post='1216467' date='May 1 2011, 12:02 PM']I wish people would stop recommending WinISD on here. It's a tool, but like any tool, unless you know what you're trying to achieve with it, it will give you a false sense of security. I don't need WinISD to tell me that the box size is much too big and the drivers are useless for bass guitar. I'm not surprised it sounds rubbish. Sell the drivers and get some proper ones. Sorry if that's not what you want to hear. Incidentally, I doubt very much if your drivers have an xmax of 10mm because they are midrange drivers, which don't need a large xmax.[/quote] WinISD is useful because lots of people here have experience with it, so can point out how to use it. I have literally no idea if the other programs will even show excursion/power charts and such which are what tells you why you have farting out. The fact it is farting out tells you something is wrong already. SVT cab uses midrange drivers, but in a suitable box (sealed one with lots of them). Quote
Balcro Posted May 1, 2011 Posted May 1, 2011 [quote name='BB3000S' post='1216490' date='May 1 2011, 12:32 PM']F0 = 70Hz is too high for bass, as been said that's more the lower level for a midrange driver.[/quote] Agreed. Looks like a PA speaker. The power rating is also confusing: "Program power" is not RMS. You should only be using the long term power figure of 130 watts. Are the speakers branded Etone or Eton? Balcro. Quote
Phil Starr Posted May 1, 2011 Posted May 1, 2011 The computer modelling programs are great if you know what you are doing because they cut down the calculation time but if you don't understand the theory then they can easily mislead you. Qts is very low for these speakers which means that any cab you build will be overdamped and will have a bass that tails off very noticeably. Fs is high but Celestion make bass speakers which have a high fs and it seems to be true that the fundamentals aren't as important as the harmonics in the way we hear somaybe that's how they get away with it. Anyway these look like midrange speakers to me too whatever the seller/manufacturers say. Another problem may be the amp. I love those old Peaveys but you seem to be operating 6x 8ohm speakers in parallel giving a 1.3 ohm load. The amp won't do this and will power limit to protect itself. You could try wiring the cabs internally in series (16 ohms each) and then running them in parallel giving a load of 5.3 ohms which the amp will be happy with. Alternatively go back to the supplier and tell them the speakers are not bass speakers and ask them what they can do about it Quote
Balcro Posted May 1, 2011 Posted May 1, 2011 Hi OzzyGreg, Further to what Phil Starr said I had a bit of a play around with winISD and the unsuitability of these drivers is confirmed. No useful bass output below 80Hz and as Phil said, it drops off dramaticaly. Power handling at 50Hz is as little as 25watts. No wonder they farted out! Most 10" and 12" [u]bass guitar[/u] speakers (not a P.A bass speaker) will have a "Fo" ( also written as "Fs") of 36 - 46Hz. I agree with what Phil Starr said about Celestion drivers, they do have high Fs's. If you can get the drivers changed, come back to the Forum and ask for more advice before parting with any more dollars. Balcro. Quote
Bill Fitzmaurice Posted May 1, 2011 Posted May 1, 2011 (edited) [quote name='OzzyGreg' post='1216237' date='Apr 30 2011, 07:24 PM']Can anyone who is familiar with speaker design software PULEEEEZE run these figures and see what [b]you[/b] come up with? (I ended up with 65 litres for a twin driver box.) Greg[/quote] Your drivers are unsuited for electric bass, the Fs is too high, the Qts is too low, and since xmax is not listed there's no way of knowing their actual power limitations. And you should not be running the drivers placed horizontally, as that halves their dispersion. [quote]WinISD is useful because lots of people here have experience with it, so can point out how to use it.[/quote]It's as good a design tool as any. It also has the same limitations as any tool: you have to know how to use it, and how to interpret the results it gives you. In the OPs case my guess is that he correctly used his program to get the best result possible from the drivers he chose, the problem being he didn't choose the right driver. One uses software to design the right cab for a driver, but a far more important use for it is to make sure one chooses the right driver to begin with. IMO these drivers should not be marketed as electric bass drivers at all, but ultimately it comes down to the consumer having to determine driver suitability, rather than blindly trust the manufacturer. Edited May 1, 2011 by Bill Fitzmaurice Quote
OzzyGreg Posted May 2, 2011 Author Posted May 2, 2011 (edited) [quote name='Bill Fitzmaurice' post='1216588' date='May 1 2011, 02:02 PM']........ but ultimately it comes down to the consumer having to determine driver suitability, rather than blindly trust the manufacturer.[/quote] That's exactly what I did in my ignorance Bill! Doh! [b]Thank you all for not flaming me!![/b] (I pride myself on being fairly intelligent in general, but this speaker/box technology mystifies me.) Strangely, these speakers from this Australian company (Etone, not Eton BTW) are highly respected from my observations over the past 20 years or more. They have been around for absolutely yonks over here. So, are Eminence Kappalites the popular choice still? I remember they were apparently the "gun" 15s a while back. What about their 10s? I think I need to bite-the-bullet and buy some proper bass 10s! Greg Edited May 2, 2011 by OzzyGreg Quote
Bill Fitzmaurice Posted May 2, 2011 Posted May 2, 2011 [quote name='OzzyGreg' post='1217343' date='May 2 2011, 06:18 AM']Strangely, these speakers from this Australian company (Etone, not Eton BTW) are highly respected from my observations over the past 20 years or more.[/quote]Unfortunately their data sheets, such as they are, look to be 20 years old. Look at the driver data sheets at Eminence and you find complete data, including SPL charts. They also have basic cab designs for most drivers, which show in-box response below 200 Hz, and list their displacement limited power and useful low frequency limits. If I was going with six tens I'd use Beta 10s or Basslite S2010. I wouldn't use six tens, but that's another discussion. Quote
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