Bill Fitzmaurice

[quote name='EBS_freak' timestamp='1494942351' post='3299794'] bass is going to be be fairly well heard (assuming you have enough power) because[b] it's omnidirectional.[/b] [/quote]Only below the point where the baffle is one wavelength across, ie., the baffle step frequency. With a typical 410 that's at about 500Hz. Above that dispersion is at best 180 degrees. Then there's the matter of the cone diameter. Above where it is one wavelength dispersion rapidly narrows. With a ten that's above roughly 1.6kHz. Put those two tens side by side and the dispersion is more than halved compared to with one, and we haven't even touched on comb filtering, which occurs above where the driver center to center distance is one wavelength.

[quote name='BigRedX' timestamp='1494926138' post='3299567'] Apart from bassist who regularly play decent-sized rooms without PA support... [/quote]IME that description applies to at least 80% of bass players. Besides, having a rig with good dispersion doesn't require jumping through multiple hoops, so why not?

[quote name='Lozz196' timestamp='1494167322' post='3293731'] Any ideas - [/quote]His first mistake was to lend his gear. While an SS amp isn't bothered operating with no load, it can be death to a number of components in a valve amp. To that end many have a switched output jack, so that if there's no load the output transformer secondary is shorted. One wouldn't expect damage to occur in a matter of seconds, but anything's possible.

One cab solution? IMO any cab worth having should be a 'one cab solution', unless it's a compact cab that can't go loud enough. If that's the case use two.

[quote name='DangerDan' timestamp='1493991921' post='3292454'] So i should ignore the "bridged rating" printed on the back of my amp? [/quote]Ideally you should ignore watts entirely, as in and of itself the power rating is almost meaningless. What determines speaker performance is voltage swing. But speaker manufacturers aren't exactly in a race to provide maximum displacement limited voltage swing ratings for their cabs, nor do amp manufacturers even mention volts, other than what's coming out of the wall outlet. The technical data provided to purchasers of light bulbs is far more comprehensive.

[quote name='DangerDan' timestamp='1493987551' post='3292397'] im worried about pushing half my amp hard (im running the amp at 2 o'clock on the volume dial) when using it in "stereo" mode, compared to using roughly half the amps power in bridged mode [/quote]You should seldom, if ever, use bridged mode, unless you have 16 ohm speakers. http://billfitzmaurice.info/forum/viewtopic.php?f=10&t=19292

[quote name='EBS_freak' timestamp='1493982609' post='3292339'] Don't powersoak/attenuate a SS amp. [/quote]+1, they should only be used with valve amps, guitar amps at that, to allow over-driving the power amp valves. If you're concerned about pushing a 2x10 too hard add another one.

[quote name='SH73' timestamp='1493847182' post='3291311'] Looks like I need an empty 412 enclosed cab then. [/quote]IMO that would be your second mistake. The EVM is not at all suited to a sealed cab, unless it's being used for guitar. If you must use them, and I only would if I had them on hand, it should be in a ported cab of at least 8 cubic feet. Even then four EVM12s will be limited to a maximum SPL of 126dB at 80Hz. That's all well and good, until you consider two Eminence Kappalite 3012HO in a 4 cu ft cab will do the same.

You can use a guitar cab with bass, but it's not going to have the lows that a bass cab does.

They're PA tops, meant to be used with separate subwoofers handling the lows. They're not going to work well with bass.

[quote name='Andy_L' timestamp='1492864714' post='3283750'] It's a 212 cheaper than anyone else is selling a 112 [/quote]It's probably an overstock or closeout item, when you consider this: https://www.amazon.co.uk/EBS-Classic-112-Cabinet-12-Inch/dp/B007OT3IPY/ref=sr_1_5?m=A10DFBRU1UE41R&s=merchant-items&ie=UTF8&qid=1492865340&sr=1-5

[quote name='Dan Dare' timestamp='1491997273' post='3277030'] I'd assumed it was just the physical limitations of a large heavy cardboard or plastic cone that limited high frequencies. [/quote]To some extent that's true, but you can make a fifteen with a low mass cone and low Qes that will extend the axial response to even 5kHz. The EVM15L is an example. It's of little benefit if the vast majority of the audience won't hear anything above 1.5kHz.

[quote name='hrnn1234' timestamp='1491994638' post='3277003'] I'm still considering alternatives before building the basschat1x12™. I'm looking into building a sealed cab because of the much simpler construction (and would also need less tools I don't have). [/quote]I assume that the plans list acceptable drivers and/or TS specs. Use them to find a driver that will work. Also, if you go sealed rather than ported you lose a lot of low end output. That's OK if it's what you're after, not so much if it isn't. You only get one chance to do it right the first time.

Most of the 'goodness' of tube amps comes from the output tubes, not the pre-amp tubes. The natural compression that takes place in tube power amps is very hard to duplicate.

[quote name='Dan Dare' timestamp='1491474273' post='3273282'] Large cones simply cannot move swiftly or accurately enough to produce high frequencies. [/quote]That's far less of a problem than the size of the cone relative to the wavelength being reproduced. As frequency goes up dispersion shrinks. To account for that the size of the cone must shrink as well. This shows how it works: http://www.acoustics.salford.ac.uk/feschools/waves/flash/diffractionslider.swf Axial high frequency limits are meaningless. What matters is 30 and 45 degrees off-axis. Dispersion, not response, is why midranges are smaller than woofers, and tweeters are smaller than midranges.

It's a property of the driver. Some 15s do go higher, but only on-axis. Any fifteen is going to start beaming around 1.5kHz.

[quote name='skidder652003' timestamp='1491220210' post='3271272'] never one to question the master but..my Ampeg 410 HLF doesn't struggle with mt SVT-CL [/quote]Nor should it, the SVT being 300 watts. But that's about all the excursion of the Ampeg drivers will allow.

With only 300w the Ampeg will do the job as far as power handling is concerned. But the BF will take a lot more should you even need it to, the Ampeg won't, and it's far superior technologically.

You can use speaker modeling software, like WinISD 0.7, to reverse engineer the cab for the purpose of comparing the low frequency response and maximum output with various drivers, and the driver data sheet SPL charts will tell you the midrange and high frequency response. But you have no way of knowing how they compare to the original drivers.

Unfortunately without the T/S specs and a response chart of the G-K driver it's a shot in the dark.

Email them again for the necessary T/S specs and SPL chart, that's the only way to find drivers that are compatible.

[quote name='Chienmortbb' timestamp='1489430824' post='3256870'] Neos v Ceramic is a bit like Valves V Solid State. [/quote]Not really, as valves and SS are totally different technology. Neo and ceramic are not. [quote]Sweeping generalisations are rarely accurate.[/quote]That particular generalization is accurate.

The specs of the EV 18 and 4018LF are quite close, so cab wise they're interchangeable. The 4018LF has twice the Pe and Xmax, so it's considerably more durable. However, the EV has good on-axis response to at least 3kHz, the 4018LF to only 1kHz. That's why the OP can't hear the 4018LF over the 210 top. The 4018LF will walk all over the EV in the lows, and the 210 is all that's necessary to handle the mids and highs, but to function well together they'd have to be crossed over in a bi-amp configuration. A 200Hz crossover would be appropriate.

[quote name='geoff90guitar' timestamp='1489350183' post='3256289'] Where's that?! [/quote]You're the one that dug it up, from over three years ago. Who's your employer? Dr. Frankenstein?

[quote name='geoff90guitar' timestamp='1489330576' post='3256066'] There got to be a difference. [/quote]There are differences in drivers. None that cause an alteration in tone or any other audio attribute are related to the magnet material. Just like zombies driver voice coils are brain dead, so they don't know or care what the magnet material is, they simply react to the flux provided, and flux is flux, be the source neodymium, strontium carbonate and iron oxide, AlNico or field coils.