Bill Fitzmaurice

[quote name='markdavid' post='420338' date='Feb 26 2009, 02:40 PM']if I upgraded to a 60W amp for practice would I get any increase in low end.[/quote] Yes, like night and day, totally worth it. Since you posted the same question in two forums it seems you want to go with whichever gives you the answer you like best. The least I could do is give you two answers to choose from.

[quote name='bassman2790' post='419955' date='Feb 26 2009, 06:16 AM']Although the 1 x 15 gave a different tone, it added no more bottom end.[/quote] +100. The assumption is made that the larger driver size will result in a lot more low end. It won't. The low end output capability of a cab is mainly determined by the total volume displacement of the drivers, Vd. The Vd of the average 4x10 is about 400 cc, that of the average 1x15 300 cc. If one is going to get more LF output by adding 1x15 to a 4x10 the 1x15 should have considerably more Vd than the 4x10, not less. Where portability is desired for small gigs I'd add a 2x10, not a 1x15. Preferably the same brand, using the same drivers, at twice the impedance of the 4x10.

[quote name='6h5g' post='416320' date='Feb 21 2009, 02:16 PM']what does this mean?[/quote] That the manufacturer succumbed to the lure of advertising hocum. In a perfect world only RMS ratings would be allowed, but it being imperfect those on the advertising end love to use other 'ratings', such as peak, music power, peak music power and so forth, all in an effort to make the amp appear as powerful as they can. When comparing amps only RMS should be considered, everything else ignored.

[quote name='Mr. Foxen' post='414789' date='Feb 19 2009, 04:39 PM']PA columns can be pretty doom: Dispersion doesn't matter when everywhere is in front of your speakers.[/quote]Even at close range having them horizontal isn't good, the tone will change literally every few inches as you walk across their soundfield. The main deficiency of columns way back when was they were intended to be stood on the floor or stage, and that seriously detracted from their function. They work best for PA on a stand that allows them to be lifted high enough so that the lowermost part of the cab is at ear level for the close-in audience, the upper drivers carrying over the heads of the audience to reach the back of the room, with ten degrees or so of down tilt. Unfortunately stands to allow them to be easily set up that way didn't exist.

[quote name='xgsjx' post='414592' date='Feb 19 2009, 01:42 PM']I just rememembered, I used to have as pair of Vox 4x10 pa speakers when I was in my early 20's. They was each about 5' high & about 1' wide & all vertically aligned. Just thought I'd share that.[/quote] The best commercially built bass cab I ever owned wasn't a bass cab, it was a 1968 Kustom 4x12 PA column w/tuck and roll Naugahyde upholstery. In 1970 I had a chance to compare one side by side with an original Fridge. The Kustom was better. Next time in London drop into St. Pauls and check out the PA. Originally installed circa 1950 it was a shining example of how well vertical sources can cope with even the most difficult venues. It was upgraded a few years ago with modern electronics and drivers but the original column speaker design remains pretty much original.

[quote name='skankdelvar' post='414448' date='Feb 19 2009, 11:16 AM']I hope that the vertically aligned SVT 8x10 will come with a free hard-hat...[/quote] One of the regulars on my forum reported how he internally divided the 4x12 guitar cabs used by his sons band into two vertical sections, then added a switch to run either just two vertical drivers or all four. He did not tell them what the switch did. They vastly prefer the sound of the two drivers only. Four tens vertically aligned, in two well designed 2x cabs for ease of transport, will outperform an 8x10 in every way. They'd also cost a lot less, and be far easier to transport. Which option do you think bass cab companies would rather sell? And which do you think those same companies will provide their endorsers with to push said sales? Engineering issues aside the bottom line with any manufacturer will always be the bottom line.

[quote name='Lfalex v1.1' post='414016' date='Feb 19 2009, 06:08 AM']Which was probably primarily driven (no pun intended!) by an entirely practical consideration; Stability.[/quote] -1. Leo placed drivers side by side, starting with combos in the 50s, for two reasons. One was to cosmetically match the width of the amp section. The other is that, not being an audio engineer, he wrongly assumed, as would anyone, that a wider radiating plane would give wider dispersion. In the 60s when early portable PAs appeared many were columns, from sources such as EV and JBL, who knew that vertical sources gave the widest dispersion. By the early 1970s they disappeared, because the average buyer couldn't understand why vertical sources gave wider dispersion than horizontal, and demanded instead trapezoidal PAs intended for horizontal arraying. Rather than stand on engineering principal PA manufacturers instead built trap cabs and took the money. Trap cabs only recently disappeared from the pro-touring genre, replaced by line arrays, as the current crop of pro-touring PA operators are for the most part well versed in audio theory and know enough not to use horizontal sources. Thanks to the internet the average muso as well will eventually know that horizontal sources are bogus and demand for vertically aligned driver bass and guitar cabs will drive the 'old standards' off the market.

[quote name='Boneless' post='413769' date='Feb 18 2009, 06:48 PM']What about 4x10s? I thought they were one of the most efficient solutions for bass When they were introduced, they were seen as kind of a revolution, and while many years have surely passed by, I can't really see the problem with 4 identical drivers in a well designed cabinet [/quote]Drivers mounted side by side leads to comb filtering in the high frequencies, and of more significance halves the dispersion angle in the midrange compared to a single driver or a vertical alignment of multiple drivers.

[quote name='redstriper' post='413686' date='Feb 18 2009, 05:31 PM']Why would I try a 2 x 15 when I'm looking for lightweight cabs?[/quote] OK, how many 1x8 or 1x6 w/high pass filtering did you try along with 1x15s w/low pass filtering? When the question posed is whether a top and bottom cab combination have been optimally engineered to acoustically complement each other those options would have to be made available to the consumer. They aren't. The options that are offered are only matched in cosmetics and footprint. Your response is to a different question entirely, that being whether you can run a 2x10 and 1x15 together with an acceptable result. Obviously the answer is yes. Whether it's the best possible sounding option one could only say if you could try the above mentioned 1x8/1x15 or 1x16/1x15 with appropriate crossover, but you can't, so you'll never know. As for Alex's perceived concessions to the conformity game, I'm sure that they will never include a 2x10 to be used with a 1x15, nor a 2x10 with horizontally aligned drivers, nor a 4x10, period. He knows better, and that's more than you can say for the usual sources.

[quote name='redstriper' post='413552' date='Feb 18 2009, 03:03 PM']I tried a lot of cabs and combinations regardless of looks and found the single 15 and 2 x 10 cabs work well together and make a sound that I'm very happy with, although two 15s are my preference.[/quote]How many 2x8 or 2x6 cabs with vertically aligned drivers and high-pass filtering were you able to test matched up with a 2x15 with low pass filtering?

[quote name='Boneless' post='413070' date='Feb 18 2009, 09:06 AM']Maybe from an "audiophile" point of view. A 2x10" cab may not perfectly acoustically pair with a 1x15", but it's a common solution: there must be a reason for it, and the reason is that many people actually like this speaker configuration.[/quote] Your reply is the proof of the proverbial pudding. Cab manufacturers build what sells, what sells is what the consumer thinks 'looks right', and what 'looks right' is what they're used to. Since virtually every manufacturer turns out the same cookies using the same cookie cutter the opportunity for the average player to hear a superior product simply does not exist. And no manufacturer, save a small entity like Alex with his barefacedBass cabs, is going to invest in the R&D and tooling for a superior product that won't sell because it doesn't 'look right', especially when same old same old continues to go out the shop doors.

[quote name='Mr.T' post='413038' date='Feb 18 2009, 08:41 AM']i.e. Trace designed their 1x15 and 2x10 as a set. I assume (some) other manufacturers do likewise.[/quote]Only to the matter of sizing them to the same width for stacking. A 1x15 and 2x10 truly engineered to work together does not and never has existed. Driver displacement and cabinet size requirements increase exponentially as frequency goes down, so while a 1x15/4x10 is a favorite combination the ratio is backwards; a well engineered system would run two to four 15s with one 10. A proper match for one 15 is one eight, or six. 'Matched sets' is a purely cosmetic matter, proper audio engineering is not a consideration.

[quote name='Jamesk86' post='411239' date='Feb 16 2009, 10:55 AM']why? The sub 15 concetrates on more on the lower end of the projection[/quote]-1. The main limiting factor to low frequency output isn't driver size, it's cabinet size. A small 1x15 won't improve low end output in this case. It would be as effective as adding a pair of oars to a motorboat in hopes of going faster.

[quote name='Pookus' post='410410' date='Feb 15 2009, 03:34 PM']My current rig is an Ashdown ABM900 and 8x10 cab. I run the 810 from one of the channels from the ABM900 - which means I have another channel spare. There are two ways I can go 1) drive the sub bass cab from the other channel possibly with a crossover or 2) get a powered sub and take the signal from the sub out. Ideally I don't want to spend much and also am capable of building my own cabs. Please help me make up my mind![/quote] For a sub to have significantly better LF performance than your 8x10 it would have to be twice as large. There's no getting around that fact. OTOH if you do build/buy a true sub you won't need an 8x10 to handle the mids and highs, a 2x10 would be plenty. In short, if you can't get the lows you want from an 8x10 it's time to rethink the entire system from the ground up.

[quote name='Rich' post='407587' date='Feb 12 2009, 08:47 AM']Certainly from personal experience, my rig sounds loads better with two 1x15s than it did with a 1x15 plus a 2x10 -- but YMMV. As the man said, suck it and see![/quote] +1. There are so many variables involved that it's impossible to predict what any particular combination will do. The advantage to using paired identical cabs is that you'll get just what you have now, but a lot more of it. Those with 1x15s who want to add tens to the mix assume that the top end will be better. For a variety of reasons it's just as likely that the opposite will be the result.

The BP102 will likely have a very different response than the Eden, probably much weaker in the mids.

[quote name='casapete' post='404391' date='Feb 9 2009, 10:38 AM']These new cabs look interesting - 1000 watts, 70 lbs etc. Anybody got one - what are they like? (apologies if this thread already posted!)[/quote] They're bass reflex cabs, using the same cabinet technology as every other bass reflex cabinet in existence, loaded with dynamic drivers that use the same technology as every other dynamic driver in existence. That means the difference between them and every other 4x10 of similar size will be slight.

[quote name='Finbar' post='396560' date='Jan 31 2009, 07:07 PM']I find they mess with my distortion sounds horribly, and I find my tone has more balls with it turned off. I just don't like the things.[/quote] Distortion and tweeters don't mix. That's why guitar amps don't have them.

[quote name='EBS_freak' post='396474' date='Jan 31 2009, 04:49 PM']if I have an 8 ohm cab, play, then switch over the cab to 4 ohm without touching any of the controls, the 4 ohm is louder... but thats presumably because the amp is putting more out at those same settings...?[/quote] At average settings, twice the power. Which requires drawing twice the current from the amp, which contributes to additional heating of the amp components. A free lunch there is no such thing as.

[quote name='EBS_freak' post='396477' date='Jan 31 2009, 04:52 PM']I dont like playing without tweeters... given what you've just said, perhaps I just like the artificial sound?[/quote]There is something to be said for having response above 4kHz. The problem lies with the 2kHz to 4kHz octave where neither woofers nor tweeters will go, and it's the lack of that octave that's artificial. A good midrange will deliver better response and dispersion than a woofer can from 1kHz with highs to at least 6kHz, which most will find quite adequate.

[quote name='bass_ferret' post='396293' date='Jan 31 2009, 01:00 PM']Are we paying extra for our cabs for a solution to a problem that does not really exist?[/quote] +1,000. Tweeters are to bass cabs as tits are to bulls. What's required are midrange drivers, which actually give useful response and dispersion that woofers cannot. They're generally not employed because they cost more than tweeters. Tweeters capable of working down to 2kHz are effective, but to make another animal based analogy they are as common as teeth on hens.

[quote name='EBS_freak' post='396071' date='Jan 31 2009, 07:15 AM']The speakers are identical apart from the impedance -[/quote] In that case the difference at small signal will be precisely 3dB, and the difference at full output, assuming the amp is able to drive both to full output, will be precisely 0dB. Again, the only advantage to the 4 ohm is if the amp has the ability to drive the 4 ohm cab to full output and not the 8 ohm, and if your amp can't driver an 8 ohm 2x10 to full output you really need a larger amp, because you've got no dynamic headroom.

[quote name='alexclaber' post='395732' date='Jan 30 2009, 03:57 PM']Here's an interesting question for y'all to consider - what impedance is the cab whose impedance curve is shown below? Alex[/quote] 6 ohms. Nominal impedance is generally considered to be within the range of 1.2 to 1.5 x DCR. DCR usually shows up as the lowest reading on a chart, in this case 4 ohms. The minimum impedance below 100 Hz, which is cabinet derived, makes it look more like an 8 ohm cab, but what the amp cares about is that minimum load area above 100 Hz, and in this case to be safe I'd call it 6 ohms. Of course, Alex's point here is that impedance is neither constant nor obvious. [quote]I've compared EBS 2x10 8 ohms with EBS 2x10 4 ohms. 4 ohm appears considerably louder.[/quote] With otherwise identical drivers the most difference that could exist is 3dB, and then only if the amp used was particularly anemic. If the difference is more than 3dB that would indicate the drivers are different in more than just impedance.

[quote name='alexclaber' post='395601' date='Jan 30 2009, 01:05 PM']I don't believe I've ever insisted that is is always a bad idea. Alex[/quote] +1. It can work reasonably well. The problem with doing so is that the results are totally unpredictable, so if you don't have the opportunity to try before you buy you're taking a big chance on the result. With identical cabs there's no question that they will work together well.

[quote name='fleabag' post='395105' date='Jan 29 2009, 07:56 PM']Does that also work in reverse , Like a 50w/4ohm amp into an 8 ohm speaker would only lose 1.5db, The difference being Still barely audible ?[/quote] At low power where the amp isn't stressed you'll get 3dB, with a halving of impedance, though 3dB isn't all that much either. But at full power there's not a lot of advantage, so if your amp is inadequate into an 8 ohm load it will likely be inadequate into a 4 ohm load. Conversely if you have plenty of output into 4 ohms you'll have plenty in to 8 as well. All things considered 8 ohm cabs are better because if you ever need to use two you can.