Bill Fitzmaurice

[quote name='malcolm.mcintyre' timestamp='1371155047' post='2110714'] I believe they need a lot of amplifier damping, like a big powerful Crown. [/quote]No moreso than any other cab. They were developed by Voigt/Bailey/Bradbury in the days of valves.

[quote name='JTUK' timestamp='1371138010' post='2110387'] That would be a warning sign to me, tbh.... but as for config, I wouldn't go up against a gtr212 with a bass 210. [/quote]+1. With a one octave drop in frequency range power/driver displacement demands quadruple. A 2x12 guitar versus 2x10 bass cab is a severe mismatch, like a heavyweight taking on a lightweight. Care to guess which one will lose? [quote]They mainly do Guitar Cabs so anything about speaker reccomendations are related to guitars[/quote]With guitar you can literally stick a driver into a box and it will work well, with no engineering whatsoever. That's the complete opposite of what's required for a good bass cab.

[quote name='Mr. Foxen' timestamp='1371049855' post='2109134'] With same power, the PS cab is going to be loads quieter, since you are feeding power to two speaker, but only one of them is moving air. Plus its a smaller speaker. [/quote]+1. Output is determined by driver displacement. The OBC115 has 343cc, the SP212 has 255cc. If you want a lot of output from a small package the barefaced Big Baby has 496cc.

[quote name='helmn' timestamp='1370974349' post='2108193'] I am probably going to line rather than stuff the TL [/quote]That's not a choice you can make arbitrarily. You must measure the response and/or the impedance and use as much damping as is required to suppress the harmonics without over damping. If you don't have the required gear to do so there's no way to get it right.

[quote name='Beer of the Bass' timestamp='1370956913' post='2107906'] I've seen it mentioned that some of the existing cabs labelled as transmission lines (like Euphonic Audio) are too short to be true transmission lines and behave more like ported cabs. What does the port stuffing do in these cabs? Subjectively, the cabs "work" but it would be interesting to know what's going on with this design. [/quote]A true 1/4 wavelength long TL is a resonant pipe. The primary resonance at the 1/4 wavelength frequency is beneficial, being added to the driver front wave radiation. There are also higher frequency resonances at the harmonics of the 1/4 wavelength frequency, and those create undesireable response peaks and dips. The line should be stuffed with sufficient damping to remove the harmonic resonances while leaving the fundamental resonance unaffected. As for the EA, its operation would be identified by an impedance sweep, but I've never seen one.

A useful TL would have to be at least 2 meters long, while low Qes/Qts pro-sound drivers don't work well in TLs. All in all they're just not a good alignment for electric bass, as they don't work any better than much smaller and easier to construct bass reflex.

When the guitar player turned up that should have affected both the mains and monitors, so the engineer should have noticed it. You should have just asked him to turn that monitor feed down between songs. Turning up your amp may or may not affect the volume in the PA, depending how the DI works in your amp. Some are pre-master, some are post-master, some are switchable. Your owners manual will say.

[quote name='The Dark Lord' timestamp='1370808635' post='2105898'] I'm thinking of replacing our PA for our three-piece band (guitar, bass and drums) with a Bose L1 Model 2 with a B1 bass module with a T1 ToneMatch module. From what I can assess, it would be fine in a band situation for up to 200 people ..... which is the most we ever do. [/quote]A keyboard player friend of mine has an L1 with two bass modules, and when he does his single act it works OK for his keys and vocals. When he plays with my R&B band only his keys go through it, his vocals go through my PA, and we generally play 200 seat rooms. For singles and acoustic acts they're OK, though grossly over priced. For a real band, forget about it.

[quote name='PaulKing' timestamp='1370783106' post='2105436'] Any amp/electronic experts able to answer me this? I use a Markbass CMD121P combo. I just replaced the internal piezo-tweeter with a better mini-horn. Is there any risk to my amp from this? [/quote]There is, as piezos generally do not use crossovers, and when they do they do not have the same topology as those used by dynamic drivers. You can't just swap a dynamic tweeter for a piezo, and the crossover for a dynamic tweeter must be specifically configured for it. You're running the risk of blowing the tweeter and possibly the amp as well.

[quote name='graham1945' timestamp='1368869585' post='2082400'] I read somewhere that you should never run a valve amp without speakers, however, does the same apply to all transistor and the new class D amps? In other words could I use a class D amp as a preamp only without connecting it to speakers? [/quote]Valves need a load, SS doesn't. Most valve amps short the output just in case you forget to plug speakers in, to prevent damage.

[quote name='aende' timestamp='1370614109' post='2103493'] So, I called Ashdown, there is nothing they can do as they have no more LG parts or modules in stock. [/quote]Try Alto, that's where Ashdown got them from.

[quote name='Lozz196' timestamp='1370257014' post='2098084'] No problems as long as: 1. Each speaker cone is rated 250 watts or more - and just having looked it seems the Eminence Beta is. [/quote]From the standpoint of not cooking the voice coils, true. But with only 3mm xmax they reach their mechanical limit in the lows at about 50 watts each, so any hint of farting out should be well heeded.

Make sure the fault is the amp and not the bass.

[quote name='Beer of the Bass' timestamp='1370078726' post='2096233'] As an aside, does anyone have an idea how much the output of a typical valve amp is reduced when running into an impedance mismatch? [/quote]Tubes have constant power output because the tubes don't see the speaker as the load impedance, they see the primary winding of the output transformer.

[quote name='dangoose' timestamp='1370038929' post='2096017'] I have 72 Bassman 50 silverface and it works well with 4ohm loads. I wouldn't run it into any load less than 4 ohms, the output transformer was designed for a 4ohm total(its not switchable). [/quote]The original Bassman cab was 4 ohms, and the head was designed to use two of them. Not knowing any better we used to run Bassman, Bandmaster and Showman heads into four 4 ohm cabs with no ill effect. We ran them into 8 ohm cabs also, no problem. As is the case with all tube amps they're happy with low impedance loads but not high impedance, so I'd not use one with a 16 ohm cab.

[quote name='jimcroisdale' timestamp='1369934528' post='2094692'] One thing I thought that might work would be to get hold of another identical cab and use them as PA. Does this sound feasible? [/quote]No. Most bass cabs don't have the flat frequency response nor wide dispersion required for PA. Some are OK, mainly 3 ways, but this isn't one of them.

They're pretty anemic, but able to handle even 1 ohm loads, so a 4 ohm 8x10 won't bother it a bit.

[quote name='JTUK' timestamp='1369415873' post='2089091'] You wont get a 410 sound out of a 112... [/quote]You may get more. An Orange OBC 410 is loaded with Eminence Beta 10 drivers, with a total displacement of 408cc. A barefaced Big Baby has 496cc. But it does use a midrange driver, so unlike a 410 you won't get comb filtering and a very small midrange dispersion angle, if you're into that.

As you should have noted by now you'll get just about as many opinions as you do responses. BTW, assuming what matters as much as anything else to you is actual output capability, that has nothing to do with the power rating, and everything to do with the driver cone displacement, T/S spec Vd. That's what you should be looking for. Unfortunately, only Barefaced tells you what the displacement is for their drivers. If you can find out what drivers are in other cabs you can search it down, but most won't tell you. As to how critical displacement is, doubling displacement gives 6dB of additional output capability, which is the equivalent of quadrupling the power. http://barefacedbass.com/technical-information.htm

[quote name='EBS_freak' timestamp='1368696845' post='2080217'] Who is this grandad clown reviving these old threads? [/quote]

[quote name='Mr. Foxen' timestamp='1368666084' post='2080062'] Don't mistake watts for volume. They don't really relate. [/quote]+1. And, to answer the original question, the best BW made has only 4.8mm xmax. That limits it to perhaps 100w before farting out in the lows. There are BWs with as little as 1.2mm xmax, making them good for only 25w. Thermal watt ratings alone mean little, as do driver diameters.

[quote name='Mr. Foxen' timestamp='1368621958' post='2079283'] Only one octave away from a sensible bandwidth for electric bass though. [/quote]It's not the first time a manufacturer chose an inappropriate driver based purely on the thermal power rating and an inexpensive price. That tradition goes all the way back to Leo Fender.

[quote name='Mr. Foxen' timestamp='1368620389' post='2079249'] Think the theme is Orange use drivers for their watt ratings rather than their suitable for electric bass bandwidth. [/quote]+1. The 115 uses this driver: http://www.bluearan.co.uk/index.php?id=EMIKAP15A&browsemode=category While it has a 450 watt thermal rating it will only take 100 watts in the low end before farting out. And note the price.

[quote name='Mr. Foxen' timestamp='1368537903' post='2078146'] which I have been assuming is why the 8x10 is a standard big stage accessory. [/quote]The 810, specifically the SVT, is the standard big stage box because they're simply loud enough to please virtually anyone. Rental companies don't want to have to stock a dozen brands, and almost no one complains about running through an SVT.

[quote name='Mr. Foxen' timestamp='1368536916' post='2078126'] I've used a cab loaded with them, not much going on very high or low, but enough in the middle bit to work fine as a cab. [/quote]In other words, vintage tone. The thing about 'vintage tone' is that those of us who played in the 60s were never thrilled about it, not being able to stray below 'A' at a decent volume without farting out. The E string might as well have not been there for all the use you could get out of it. Given the penchant for guitar players to write songs in the key of E back then it led to very thin bass parts.