Bill Fitzmaurice

[quote name='small_lump_of_green_putty' post='524346' date='Jun 25 2009, 07:09 PM']I still don't understand why a seal is important around the edges. As for the lubrication, there's something called teflon these days, isn't there? [/quote][url="http://electronics.howstuffworks.com/speaker5.htm"]http://electronics.howstuffworks.com/speaker5.htm[/url]

[quote name='BarnacleBob' post='523413' date='Jun 25 2009, 05:58 AM']So 450-500 is an ok price but possibly swap the spkrs (if still origina)l out of the cab? BB[/quote] -1. The cab isn't worth putting new drivers into. Basically it's landfill.

[quote name='BarnacleBob' post='522758' date='Jun 24 2009, 12:32 PM']should i be looking for to make sure I'm not buying a dog/paying over the odds for it Would i be better going for the reissue tweed cover 4x10 Bassman combo. or an original if affordable and available? Only ever bought new amps up til now. BB[/quote] Not a bad amp, if you've got efficient enough speakers to work with only 100w. The Fender speaker, however,is absolute trash. The pictured model looks to be early 1970s. I don't know if they did a reissue, or if they did, why. It was a 2nd tier rig 35 years ago compared to an Ampeg V4, let alone an SVT. The Bassman 4x10 is a great guitar amp, useless for bass outside the studio. A pristine '59 is probably worth more than what you're driving, but only to a guitar player/collector.

[quote name='alexclaber' post='521743' date='Jun 23 2009, 09:38 AM']I'd like to get some hard data on driver failures. I know the vast majority of Acme failures are not voice coil related despite the huge power often being used to drive them and I've heard from other talkbassers in the pro-sound world that >90% of failures are mechanical failure, not voice coil overheating. Alex[/quote]My sources include Eminence and trade-only publications. A high reported incidence of creased cones usually indicates an insufficient xlim to xmax ratio.

[quote name='alexclaber' post='516909' date='Jun 17 2009, 04:14 PM']The more common failure method for bass guitar drivers and direct radiating subwoofers is mechanical failure.[/quote] Most driver failures are electrical, ie., voice coil burn out. The primary reason is thermal power compression. Driver voice coils driven with more than 100 watts or so get very hot. When the wire of the voice coil gets hotter its resistance increases, reducing driver sensitivity, which reduces output, which the player more often than not will compensate for by turning up the amp. This further heats the voice coil, further reducing output, and this cycle continues until the voice coil heats enough to either burn out or for the adhesives holding it together to fail. Prevention of this syndrome is why it's a good idea to run twice the speaker power rating than amp power rating. This practice also better matches the amp output to the amount of power than the average speaker's excursion limits allow it to actually make use of. It's also one more nail in the coffin of the Myth of Underpowering.

[quote name='riff raff' post='518965' date='Jun 19 2009, 06:22 PM']that article explains it very simply. is there something similair to explain the effect of having them side by side?[/quote] The exact same result will come from having them side by side, but in the lower midrange frequencies rather than the bass. The exact same result also comes from having drivers side by side in a single cab, but in the upper midrange frequencies.

[quote name='riff raff' post='518772' date='Jun 19 2009, 02:20 PM']what about if they were positioned either side of the drummer.he loves it.plus would give my rhythm guitarist a great monitor.he loves it too.in rehearsal he's always hanging around my cab.[/quote]Even worse. Read this: [url="http://www.prosoundweb.com/article/in_search_of_the_power_alley/"]http://www.prosoundweb.com/article/in_sear...he_power_alley/[/url] [quote]whats the relevance of the old ampeg cabs?? pretty sure mine is a very old one.i'll have to check.[/quote]The original CTS were 30 watt guitar drivers, as were the first generation (early 70s) Eminence that were copies of them. The result was great highs, but limited low end capability, so a pair of cabs were necessary to handle the SVT head. Later drivers have better low end, and don't require two cabs, but they also don't have the highs of the earlier cabs.

[quote name='riff raff' post='518675' date='Jun 19 2009, 12:38 PM']i,ve already got one ampeg 8x10.just want another to run them both together.[/quote]That opens a can of worms, for if you place them side by side you'll halve the lower midrange dispersion and exacerbate the upper midrange comb-filtering that already exists with one. Stacking them vertically gets around those problems, but isn't practical. Frankly I can't imagine the need for two, one is plenty to handle any stage size, and if it's not enough for the room, well, that's what PA is for.

[quote name='KASH' post='518419' date='Jun 19 2009, 09:31 AM']...and now in English? [/quote] If you don't understand what I said you wouldn't be able to build it anyway and will have to settle for that factory built stuff.

[quote name='Mr. Foxen' post='518260' date='Jun 19 2009, 07:00 AM']Doom. Always wondered what Ampegs have over all the other 8x10s. Is it just the name?[/quote] It's the drivers, which are particularly well suited to the sealed cab. The original CTS and first generation Eminence are preferred tone-wise, as they were guitar drivers with a much better high end. A modern alternative would be a 3015LF bottom cab to provide the low end, crossed over to a vertical 3x10 cab loaded with guitar tens at 200-300 Hz to give the high end of the original.

[quote name='gamester4520503' post='516975' date='Jun 17 2009, 05:19 PM']Found this - might be a tad OTT though! [url="http://www.soundselectric.com/600w-piezo-tweeter-box-p-248.html"]http://www.soundselectric.com/600w-piezo-t...-box-p-248.html[/url][/quote] OTT maybe, but useful, no. Tweeters should never be mounted as they are in that box. Vertical or in a concave horizontal array are OK, but never a convex array. It's faulty implementations like this one by persons with no audio knowledge that give piezos an undeservedly bad name.

[quote name='Stewart' post='517371' date='Jun 18 2009, 08:40 AM']I agree absolutely - having different frequencies set for the two cabs is a very bad idea[/quote] +1. Bi-amping is only useful with cabs that are specifically engineered to operate within different frequency bandwidths, not with cabs that cover the same bandwidth.

[quote name='BenK' post='511412' date='Jun 11 2009, 11:51 AM'][font="Tahoma"][center]could you use a guitar valve head for bass if you had a bass cab? [/center][/font][/quote]Yes. With valve heads there's not all that much difference, save for with or without reverb.

[quote name='joegarcia' post='510624' date='Jun 10 2009, 03:39 PM']Good quality passive DI just before the amp (just for low end) and the SM57 (for mids and highs). I'm a live engineer and this is what I do regularly. attackbass has a good point though. If you are working with unfamiliar or even incompetent engineers (there are plenty of them working the toilet circuit) then something like a Sansamp or Tone Hammer will be a good investment. If you play decent venues or have your own engineer who knows your sound, or both then go for the mic and DI route.[/quote] +1. Mics are a necessity to capture the tone of the amp/speaker, but that's all above 100Hz. Below that a DI gets the signal without the stage mud. Better FOH engineers will high pass the mic channel as high as even 300 Hz, using the DI below that. The best will high pass the DI at 60-80 Hz, so that the sound out of the PA is reasonably close to that on stage. The worst will run the DI flat and boost the bejesus out of the low EQ and totally corrupt your sound. You don't need to play a toilet to hear that, even in pro-touring I'd rate only 25% of FOH engineers really good at mixing the bass, and nearly all of them are either bass players themselves or also work as studio engineers. Or both.

[quote name='Hodge' post='509059' date='Jun 9 2009, 09:32 AM']Also, is there a chance of any damage to the amp[/quote]Yes. [quote]I'm trying to get an idea of just how bad the advice of the shop staff was[/quote]Bad enough that said person should be summarily sacked.

[quote name='TGEvans' post='502386' date='May 31 2009, 12:26 PM']Hey all, anyone here run two 2x15's together???? thinking of adding another 2x15 to my existing 2x15!. any feedback would be cool,tim[/quote]Get a better 2x15, or better drivers for the one you have, or a decent PA as noted above. A really good 2x15 will handle any gig if the PA is right.

[quote name='Finbar' post='494720' date='May 21 2009, 05:22 PM']Hmm. The idea was to keep it compact and neat, so all to one 3u amp/rack, and two small cabs.[/quote] Not going to happen. Going down one octave doubles the power requirement and requires a speaker that can both handle the power and deliver the response. It won't be compact.

[quote name='umph' post='494286' date='May 21 2009, 09:32 AM']ohmage[/quote]Impedance.

[quote name='dood' post='493648' date='May 20 2009, 02:47 PM']Yes, I think our resident experts have elluded to the fact that putting too many different sized speakers in one box causes all sorts of problems.[/quote] +1. The only justification for a box of that sort comes from marketing departments, who cater to the desires of customers who have no clue how speakers work and will buy anything if it's hyped enough. It's to bass players as Bose is to housewives. One is too big with too many drivers to work well, the other at the opposite end of the spectrum, the net result is the same.

[quote name='bubinga5' post='490940' date='May 17 2009, 05:22 PM']My Q is why was the amp clipping? Was the (so called) Gain to high?[/quote]Yes, especially if his bass was active. [quote]Am i right that ideally you should be using a cab or cabs that are roughly double the wattage of the amp??[/quote] Not really. You use whatever is required to get the volume you need. In most cases an amp can drive to full output a cab that's twice its rating, but that's a very broad generalization. [quote]Also what is the best cab to add to a 2x12?[/quote] Another identical 2x12. If you must go 1x12 make it one from the same manufacturer, loaded with the same driver, with double the impedance of the 2x12.

[quote name='Cornfedapache' post='485222' date='May 11 2009, 12:51 PM']Well that's what I originally thought... So was getting confused when I saw it being talked about to power a stack... Alice Klarr now![/quote]You wouldn't use it to power a stack, but they can be used to drive a power amp that will power a stack. But their main claim to fame is built in speaker emulation circuitry, which is a fancy way of saying they cut the highs and lows and boost the mids, in an attempt to duplicate speaker coloration.

[quote name='Cornfedapache' post='484247' date='May 10 2009, 07:04 AM']Ahh so it's an effects box, of sorts meaning that you can play any amp set up and get teh same tonal results??[/quote]The original intent was to use it as a DI to a recording console, instead of mic'ing an amp.

You're operating under the common misconception that you actually need, or for that matter can use, two channels of 500w/4 ohms. The 320 watts or so available at 8 ohms is more than enough to drive most cabs on the market to full output, while the additional 180 watts you'd get with a 4 ohm load would be inaudible. If Ashdown made companion 4 ohm cabs the next complaint would come from those who felt that they had to use two per channel and why didn't Ashdown make the amp 2 ohm capable.

[quote name='chris_pokkuri' post='480083' date='May 5 2009, 11:54 AM']I'm definately not hung up on a 1x15/4x10 combination (hence my plan for the BigOne) - which is why I asked for alternatives to that combination that would fill out the sound of the band in a way that I can't get from my current setup. I think you are right in that I just liked the improvement in sound from using just the 4x10. Cheers![/quote]If you want to add to a 4x10 I'd do a 2x10, preferably loaded with the same drivers, with impedance twice that of the 4x10. That will give you a system scalable for low, medium and high output requirements.

[quote name='chris_pokkuri' post='479714' date='May 5 2009, 05:04 AM']That seems my most likely route. If I can get a similar volume and sound as the 1x15 + 4x10 weighing in at a total of 180lbs (Thats way heavier than me!) from a lightweight setup of LH1000 + Bigone weighing at under half that, it would be amazing! And I would be very happy <--- See![/quote] Don't get hung up on the 1x15/4x10 route. When you combine virtually any two cabs the sum will sound better than either on its own. All things considered the 1x15/4x10 is a poor combination, albeit a popular one. As to why it's so popular, I repeat : [i]When you combine virtually any two cabs the sum will sound better than either on its own.[/i]