LawrenceH

[quote name='alexclaber' timestamp='1355319538' post='1896850'] If anyone doubts that speakers change a lot due to mechanical parameters shifting, notice how different your car stereo sounds when you've just de-iced the car compared to half an hour into the journey with the heaters on full blast. There's a big change in bass response! I wonder how well boot-mounted subwoofers work in the winter (mind is in the rear footwell!)? [/quote] I think that's not the easiest example, since half an hour into a journey road surface/engine noise is going to be pretty different! Thinking about your graph above I'd guess the off-axis response might alter even more drastically for a given position as changes in stiffness altered break-up behaviour etc. Could be a bigger deal in guitar speakers.

Hurrah! Well done Alex What difference do you think is attributable to temp versus 'break-in' here? EDIT: assuming the driver was 'fresh' for the first measurement, realise this might not be the case!

[quote name='Bill Fitzmaurice' timestamp='1355282022' post='1896384'] While I deal with theory all the time I don't blndly accept it. I verify it by taking my own measurements, of both drivers and finished cabs before and after break-in. [/quote] Indeed, and this discussion would be much richer if you shared any of those currently intangible measurements, indicating how much difference it can make! Or at least gave some expert insight into how T-S params like Cms and Rms tend to change in the real world, and the effect this would have in simulation... [quote name='Ghost_Bass' timestamp='1355309520' post='1896614'] - No, Just play the damn thing! The amp's EQ is there to shape your tone at any moment. Cheers [/quote] Agreed, which is exactly why I said [quote name='LawrenceH' timestamp='1355280857' post='1896383'] So I'll carry on breaking in speakers if I'm building/testing a cab, and in all other situations I just wouldn't care! [/quote] and I think most others have expressed this sentiment as well. Of course interest in this is more than just academic when you're building a cab, and from a manufacturer's perspective, if the cab sounded noticeably weaker/harsher until broken in then it could have a negative impact on sales.

[quote name='Bill Fitzmaurice' timestamp='1355272098' post='1896345'] In fact, I was. Everyone's entitled to an opinion, but if you want to offer an expert opinion you first must become an expert. Like Vance Dickason. Or the guy who's name is directly below his on the masthead of AudioExpress magazine, and Speaker Builder magazine before that: Mine. [/quote] Sorry Bill, but argument from authority is on the naughty list: [url="http://www.theskepticsguide.org/resources/logicalfallacies.aspx"]http://www.theskepti...lfallacies.aspx[/url] Now I wouldn't claim to be an 'expert' but if people want to argue scientifically, they have to understand what science is, and the major methodological differences between proper scientific method, anecdotal evidence, and engineering solutions. So far on this thread there has been a load of waffly rubbish, some subjective anecdotes (nothing wrong with that but you have to recognise it for what it is) and some actual measurements based around a scientific theory of how loudspeakers work, provided by only ONE person. The measurements are one half of some science, but more measurements would be needed to do it that way - which those "arguing from authority" seem strangely reticent to provide. A shame. The other half is the theory. It's easy to solve this argument more objectively, at least for the bass response, [b]if we accept that the theory is true[/b], and actually bother to LOOK AT IT! Which no-one arguing seems to have done either, at least not in any depth or with adequate explanation. So, assume the Thiele-Small model is true. Mmd (or we can use Mms), Cms, Re, Rms, Sd, Bl (and Le). Those are the fundamental parameters (not necessarily the ones you'd measure) that can't be completely described by each other. However Fs, Vas, Qes/ms are all functions of those parameters. If we accept that material compliance can vary over time, easily demonstrated by flexing a piece of card, then we can vary that one parameter in the model and see what it does. WinISD can even do it for us to save having to do horrible maths. Just make a fictitious loudspeaker using only the fundamental parameters and let it fill in the gaps, then make another that differs only in Cms, let it fill in the gaps again, and see what happens. When I tried this, starting with a real speaker spec for my base parameters, as compliance increases the effect of the change becomes less and less. What this implies is that the effect of a change in Cms will vary not only dependent on the magnitude of the change, but that the absolute starting value is also important, ie how much suspension stiffness is limiting cone movement in the first place. This is pretty obvious really, when you think about it mechanically. (Go back to the derived parameter definitions. Note that while Fs and Vas do indeed change in complementary directions, Vas is defined as proportional to Cms but Fs is inversely proportional to the square root of Cms. This is important because it means they can't totally balance each other out) Note that in Stevie's measurements, Cms is not the only fundamental parameter to vary. But you can't assume they'd always vary in totally complementary fashion and doing so doesn't fit with the model as described. In a way, it's clear that if one or more of the fundamental parameters in the model can vary over time, they can't always just cancel out or they wouldn't be in the model as fundamental parameters in the first place! In the real world? Most measurements Stevie references and provides seem to suggest it's fairly subtle, but subjective experiences here suggest otherwise, quite probably (and obviously) related to the Cms's original contribution to cone movement. Personally, I'm fairly sure I've heard it happening in some Deltalites, because it didn't really seem subtle at all and loose objects were certainly vibrating more later on than at the beginning. There's a limit to how much your ears can adapt! Though now I wish I'd had a mic up recording the process. The other issue as mentioned elsewhere on the thread is the midrange - the T/S model doesn't deal with that. So I'll carry on breaking in speakers if I'm building/testing a cab, and in all other situations I just wouldn't care!

So that's recommendations for 2 cabs weighing about 90lb total, for someone asking if they could get a 1 cab solution weighing under 30lb?! A typical neo 212 weighs under 60lb and is plenty by lots of people's standards...([i]edit:[/i] not disputing the tonal qualities of the aggies which a lot of people really like) Personally I could get by gigging with a mid-level 112 for a lot of indoor scenarios, but if you wanted the 'biggest' 112 sound you could get in a reasonable lightweight form and had the watts to drive them, then the BF Big Baby, Vanderkley 112MNT or even Kappalite-loaded BFM Jack 112 have the best output potential IMO. The choice depends a lot on preferred voicing for me - where you want the volume has a big impact.

Takes up less floor space but still the cabs are squat enough to be stable, gets the speakers closer to your ears, you get a little benefit in terms of mid-range dispersion, AND the TE badges are the right way up! What's not to like about the vertical stack? If you got a second set of cabs, then 1. It wouldn't be technically ideal to have them side-by-side but 2. It's hard to see how to do it otherwise and 3. You probably wouldn't notice or care about the sonic difference

[quote name='stingrayPete1977' timestamp='1355221180' post='1895439'] Where do you draw the line with your argument though? [/quote] 3dB difference is a fairly standard place to draw the line, and is IME sensible for live use. You can hear a difference of a lot less than this in a very well-balanced mix though.

[quote name='fleabag' timestamp='1355232401' post='1895658'] Thanks a lot Phil - all advice noted. I dont mind shifting the wood I have tried to find another Jack - mine has 2 Betas @ 250 watt 8 ohm each, so another like that would be ideal, but they dont seem to be selling much anymore. I think the depreciation on those after someone's spent time and money building them is a big factor. At least 50% loss and more. So, i'm stuck with what i have, but i will try the crossover out of the BP8.... any recommendations as to which Hz value I should send to the BFM ? The crossover allows anything from 80hz and above, upto 500hz and above. I will experiment, but It'd be handy to know your thoughts on this PS is there much of a volume difference ( that can be heard ) between 350 watt @ 8 ohms and 500 watt @ 4 ohms ? [/quote] I'll chip in again, as I own some Jacks (if you want a couple of slightly rough unloaded Jacks 110s, let me know!). For 15 'sub' use I'd try crossing over a bit higher than usual, round about 150Hz-ish as that's where the horn loading starts to take effect. It does rather depend on how loud the 15 is in comparison though and personal taste in the sound, so experimenting a bit higher or lower would be sensible. There isn't much volume difference between 350 and 500 at all at the best of times, and if the drivers are being pushed to their limits then it will be virtually nothing. If you're driving the power amp to the edge of clipping to get just enough volume at 350 though, then the extra could make more of a tonal difference - for PA use I always liked having a little extra clean headroom. Btw Phil I agree that people worry more than necessary about mixing cabs, my concern with the Jacks is whether, running full-range, the horn loading would mean phasing issues were shifted higher up to a more critical region, so it could matter more than usual - perhaps unfounded though, since the Jacks would likely be so much more sensitive in this region anyway.

The Jack design is very 'voiced', has a big bump in the low mids but a big trough higher up (obviously depends a bit on what drivers you load into it). If you like that sound then the best thing to do would be add another identical cab. I'd be a bit wary of combining a J210 with another type of cab both running full range, but you could use an active crossover to split the signal and run the 15 as a sub, to take the strain from the J210 drivers at the low end below horn cutoff. Then you needn't worry about finding a 15 that plays nicely higher up.

But, two smaller cabs are a lot easier to move than one cab that's double the size If you want a lightweight 4ohm 410 that could actually handle a lot of watts and make use of them then you might take a look at the Aguilar SL410 - rapidly discontinued I think due to Aguilar having issues with Eminence neo driver supplies. Remaining stock is still available from a few suppliers I think, it's not cheap, but the price reflects the quality of the drivers its loaded with. Btw the Trace cab wouldn't be a great platform for upgrading because the port size isn't big enough to cope, you'd get issues with chuffing around resonance if you did put more power in regardless of what drivers it was loaded with.

Cheers, that's very interesting thanks. Did you add any additional bracing? Looks like there's a bit in the second pic down on that page. Also did you do any tests after they were built (other than the 'firing it up and going '&*% that's loud'' test)? There's not been much discussion of horn designs on here at all, other than a bit about the BFM offerings.

Really depends on the driver units as JT says, but given that the GK 10" and 12" drivers are probably based around the same motor design you might expect 4x10s to give roughly equivalent performance to 2x12s with the added advantage of modularity. A good 410 is very loud. Recently I've been gigging a single 10" but it's a better driver than you'll find in any commercial (bass guitar) speaker, I EQ to suit the limitations and can usually rely on FoH for low-end reinforcement. All this really depends on what kind of volume levels you want and what sound you're after?

Just from using them in rehearsal rooms I wonder if a lot of the problems with those Trace 410s farting out is down to their being tuned a bit high to give more upper-bass oomph, leaving the cones undamped at lower frequencies. At any rate it wouldn't cost anything to try blocking one of the ports, which would lower cab resonance and offer a bit more protection. Depends where the problem lies though, it could make it worse - but worth a go perhaps.

[quote name='neepheid' timestamp='1355061249' post='1893457'] If you want more basses then go find a way to make it happen instead of bitching on here about it in some sort of attempt to make me feel guilty for any success that I have worked hard to achieve. [/quote] I didn't see any bitching, just an expression of surprise at the collections that some people amass, without pointing to anyone specific. No need to be so defensive!

Hah, bass cabs are the stock cars of the speaker world - you get some real souped-up labours of love, and some right old bangers cobbled together with whatever was going cheap! Even to the extent of summarily changing driver type loaded into a cab model for (understandable) reasons of cost and availability. But generally, stuff at the mid end of the market up works well enough in the real world if you spend some time working out how to coax the best from it, and some of it works very well indeed. Never been a better time to play in terms of gear portability, price and sound quality IMO The OP specifically mentions impedence in the title. Largely a non-issue with solid state stuff as long as you don't go below the minimum spec. Certain driver/cab/amp combinations don't play well where they've stretched the spec a little though - impedence is only nominal after all, but that's rare enough these days I think.

[quote name='Big_Stu' timestamp='1355004712' post='1892966'] alleged knowledge........... ad nauseum. [/quote] Hi Stu, that'll be nauseating people like me then? I do go on a bit sorry! Mixing and matching can get you closer to what you want than set manufacturer combinations, really depends what you're after tonally and if it matches with what a manufacturer is aiming for. I think the idea that no manufacturers ever put any thought into their cab designs whatsoever beyond appearance, is a bit of a sweeping generalisation. There's always been good stuff out there and a lot of modern manufacturers have upped their game IMO.

As a 'born again' Fender user I'd still rather spend 2 grand on a Yammy than a new Fender! Would love to try the 2024, but then again perhaps it's better for my spiritual well-being that I don't

If that bassline wasn't sitting high in the mix with an EQ that boosts the mids right over the vocal register, it wouldn't seem nearly so 'busy'. If you solo'd some lines from classic recordings and EQ'ed them like that you might be surprised... OTOH that slap line is very tight and nicely realised/recorded but the core tone for me is pure extra mature cheddar...

Just from trying VM in shops, I got the impression the VM pickups are very thick at the bottom, with a much-restricted top end. By contrast the MIMs tend to sound thinner but have greater bandwidth. Very different in character I'd say, which one you prefer though...? More expensive pickups tend IME to let you have a bit of a best of both worlds whilst still leaning one way or the other. My Fender 75RI jazz pickups, which I dropped into a MIM Classic 70s J cut like the proverbial knife but still have a respectable bottom end. My DiMarzio Model Js are thick like the Duncan Designed, but with wider bandwidth/better top-end.

[quote name='alexclaber' timestamp='1354881921' post='1891526'] I'm not trying to push my products, I'm just trying to clarify the truths. [/quote] We should probably not continue on this thread! Maybe I'll start a different one at some point. But I don't think we're in much disagreement about the 'truths' (though from my own experience mixing I'd fundamentally disagree about the big low end from stage cabs+FoH, muddies up the mix far more than it helps and no cab will replicate the 'slam' of 'decent big rig' PA subs). What we're talking about though are objective limitations applied to subjective issues - timbral preference, perceived volume, sound quality. 'Education' ie how to use the kit wisely is as you say important. But if you know how to do that, then apparently limited kit can do a good job without breaking the bank or your back. There's a lot of ridiculous talk on here about how people 'need' this and that, fuelling the GAS, where I feel a bit of perspective and a bit of knowledge can save a lot of money and dissatisfaction leaving people to do what you say and get on with playing.

Looks really interesting, is it actually a sealed design?

[quote name='alexclaber' timestamp='1354871424' post='1891354'] The 12HPL64 only has similar sensitivity at 1W. Turn up to 100W and you're looking at around 3dB less sensitivity as the thermal and mechanical power handling are both about half as much as the 3012HO. And it won't handle much more than that without grumbling. [/quote] Which is TOTALLY irrelevant when you're looking at feeding a single speaker from a max of 250 watts with a crest factor of 10dB and you still have headroom, which is exactly my point. I think you are stretching that point for the sake of promoting your product here which isn't like you. We both know the advantages of drivers with more power handling, but also that the extra doesn't come at zero cost and that the performance benefits are irrelevant if you have a good driver working within its limitations. I don't think you need to worry that people will suddenly stop seeing the advantages of your cabs, they're very good and the price is still keen compared to other offerings. For me, the main gains offered by the long excursion neo drivers and modern amps is the ability to get to performance volume from a far smaller and lighter footprint. But 2 12s even in old money is enough for a lot of situations until you start with the smiley EQing. Then the problem becomes not the rig, but the person using it. Big bottom is nice but tonal perception is in the midrange, where extra volume is very cheap. I'm sure you'd agree that many cheap cabs are/were let down by lack of midrange clarity, and midrange performance is very important in your product line. [quote name='alexclaber' timestamp='1354871424' post='1891354'] That very much depends on the bassist and the band and the gig. You could have two different bassists with the same band at the same venue and one could easily need 6dB more output than the other if his tonal preferences are skewed towards the lows. That requires a cab to move four times as much air and with power compression considered you're looking at needing maybe ten times as much power from your amp. [/quote] Of course, but for a bigger gig where that kind of performance matters most, significant cab output low down is a problem, not a solution, from the point of view of FoH for reasons of both overall control and interference cancellation with subs. Again you know all this but are choosing to highlight only the advantages when every solution is in fact a compromise. The weak fundamental/first harmonics from sealed cabs are a blessing for mix engineers!

[quote name='The Dark Lord' timestamp='1354837225' post='1891216'] Well, he has gone about it the wrong way/ [/quote] Oh dear. On the other hand, getting the amp first allows use of the headphone out for practicing, use of the valve pre-amp to colour the sound before DI for gigs with FoH where a cab is a non-issue, an easy portable solution for gigs where there's a house cab so you don't have to bring your own... I don't really understand your antagonism. Secondhand for the OP is a good option, though even there it's hard to beat the GK, you'd be hard pushed to find a pair of neo woofers alone for much less than that price.

[quote name='Ultima2876' timestamp='1354816194' post='1890827'] Back on topic, The GK 2x12 MBE is a good choice if you plan on being sensible and using a step-by-step approach. However, you could always get a bank loan (or sell a kidney) and do what The Dark Lord suggests [/quote] It really depends what the gigs are. My dad and I built a pair of reflexed 112s for bass back in the 90s, using fairly decent (but still pressed-steel), carefully chosen PA woofers. This was at a time when it was all about whether 10s or 15s were best(!), which seemed rather silly to us even at the time. We didn't build another of that config (though plenty of others) because that rig still gets loud and clear enough with a 300 watt head for any gig they've ever been asked to do, there's no tonal compromise either. Horses for courses, have to think about how loud you need. I would say though, always get more speaker surface area if you want the option of going louder, which is why the 212 is a good setup IMO

[quote name='alexclaber' timestamp='1354813353' post='1890780'] You don't need much power at all, you just need more power the louder you want to play. 'Maximum performance' is basically getting the SPL and tone you need for your gigs - if you don't need to be very loud then you don't need lots of power. Cabs with larger voice coils and higher excursion are louder than cabs with smaller volce coils and lower excursion of equal 1W sensitivity when both are driven with a mere 100W amp, because they maintain more of their 1W sensitivity through reduced voice coil heating and greater motor linearity. Use more power and the difference becomes even more obvious but that doesn't mean it isn't still there at lower SPL. I'd have expected better from you Lawrence than referring to a passive loudspeaker as 'overpowered'! [/quote] Haha, well that's fair but a semantic quibble We both know full well what I meant in the context of the OP looking for a cheap but acceptable cab for a 500w head and for 'maximum performance' by your definition it's not really necessary to spend a lot of money if you don't need to go loud. With enough power your cabs are capable of going WELL beyond volumes that people use at most gigs and that comes at a price in terms of money, and also, even with neos, woofer weight (comparing say Kappalites with Deltalites or even lighter pressed-steel woofers). If you don't even need to drive a 212 at close to the 500 watts you have on tap for your gigs, sensitivity gains are a non-issue - loud enough is loud enough. The flip-side to your point about [i]larger[/i] voice-coil diameter, is of course that the [i]longe[/i]r voicecoils of high-excursion drivers are less efficient - the Kappalite HOs are very loud but could be made even more so by sacrificing excursion and power handling, and of course the broadband sensitivity of the LF is much lower. The older, smaller VC diam B&C 12HPL64 is similar in sensitivity to the HO for that reason and sounds very nice indeed - just won't go as loud. But you know all this. Of course I'm aware that you have your cabs to sell but I remember the early discussions about high excursion designs in the context of ERB down to low F# I also know what the power distribution v frequency looks like for low notes on some typical 4-strings, and my chances of noticeably exceeding excursion limits on even reasonable woofers with only 500 watts available!