Bill Fitzmaurice

A driver upgrade may be possible, but you'd have to know the full set of T/S specs of the original to make that determination. As for a 212 versus a 112, the 212 will almost always sound better, no matter what the drivers are. For that matter virtually any two cabs together will sound better than either alone. That's a basic property of how speakers work. As for this: Changing from an 8 ohm to 4 ohm load will have little, if any, effect. Many factors can result in an improvement, but impedance is seldom one of them.

That's not true. In the same 2 cu ft ported cab tuned to 45Hz or in 2 cu ft sealed the Beta 12 and BP122 have virtually identical low frequency response. Neither will have very good low frequency sensitivity in a sealed cab, because it's a sealed cab.

Using a midrange driver with a BP122 isn't a bad idea, using a Beta 12 as a midrange driver is a very bad idea. It's not about response, it's about dispersion, and the midrange/HF dispersion of a twelve is horrid. That's why guitar cabs beam. The right tool for the job is a six or an eight.

It could be a microphonic tube. Gently tap on them with a pencil to find out.

[quote name='chris_b' timestamp='1509963042' post='3402835'] All TC RS cabs are 8 ohm. [/quote]There's a reason for this disclaimer: [i]As long as you use TC cabinets, most of our amps can actually handle 3 cabs simultaneously. [/i] The reason is that they're not 8 ohm cabs, otherwise their amps would be able to handle any three 8 ohm cabs. In BGM issue #6 they measured the RS210 and RS212 at 10.54 Ohms and 11.54 Ohms respectively.

[quote name='Zummerbass' timestamp='1509898054' post='3402414'] Do I get a PC 210t [/quote]If you like what you have but need it louder add another identical cab. [quote]Or another RS cab? 115 or 212. Heavier but well matched. [/quote]Well matched cosmetically, but otherwise, no. To be acoustically well matched is to be identical.

Speakon connectors are made in two, four and eight-pole configurations. The two-pole cable connector will mate with the four-pole panel connector, connecting to +1 and −1; but the reverse combination will not work.

[quote name='discreet' timestamp='1509643382' post='3400573'] I think you're right - you have the knowledge BIll, how about a short post on driver substitution and I'll get a mod to make it sticky? [/quote]I'd only do so if the topic was locked. Back when I still frequented talkbass they asked me to explain how driver phase response affects mixing cabs. It turned into a complete clusterf*ck when the usual bunch of idiots decided to fill the thread with Luddite nonsense. If the topic had been locked, or if the mods had done their jobs and cleared out the detritus, it wouldn't have given me one more reason to leave there. Lesson learned. To do it right would take a fair amount of time, which I'd only invest if I was assured that it wouldn't turn into an endless debate.

I think the need for a sticky that explains what it takes in terms of the tools and knowledge required to successfully substitute drivers is long overdue.

The 2510 has more xmax. Low Qes chokes off bass response, 0.30 is as low as you want. But don't expect miracles, 17L is less than half what you need for best results. Long wavelengths at high levels don't come out of small cabs.

Since you have the specs on the original you just need to match those within 10% to determine if another driver is compatible, except for xmax. At 2mm it isn't even mediocre. 4mm is the least you should consider. I'd use the 2510 myself. As for the 3010MB the Qes of 0.21 rules it out as a bass driver.

You would not high pass higher than 50Hz, and it would have to be an active filter, not passive. The Thumpinator is one example.

[quote name='TheRev' timestamp='1509176748' post='3397111'] I have used cabs (usually 4x10s or 8x10s) at festivals where the notes all seem to run together, with the result that I can't really hear what I'm playing.. My 4x5 sounds clearer and more articulate to my ears [/quote]That can be chalked up to the better upper midrange response and dispersion of the smaller drivers. It's why some cabs are now made with larger woofers for the lows and smaller midrange drivers for the mids. PA and hi-fi cabs have used that arrangement since the 1950s. Bass cab manufacturers, and bass players, are slowly coming around.

The cone diameter isn't the same as the frame size. Even with the same frame size the cone area, T/S spec Sd, differs from driver to driver. There are some fives where four of them will have the same, or even more, cone area than some tens, but by and large they won't.

[quote name='Dandelion' timestamp='1508845794' post='3394784'] Providing a guitar head is used. Is the fact that it is tuned differently going to make it sound crap? [/quote]There's far more to it than tuning. Guitar drivers extend much higher in their frequency response and have short xmax, which causes them to distort at low power levels. [quote]Fender Bassman 410 combo's have been used by guitarists for many years.[/quote]That would be a reference to the '59 Bassman, and reissues of it. It's a great guitar amp because it used guitar drivers in an open back cab. By the same token what made it a great guitar amp also made it a horrible bass amp. The original was only produced for three years. [quote]Acoustic guitars sound esp good through a bass amp [/quote]If it has a tweeter true, as a guitar amp without tweeters loses a full octave or more of the harmonics of the acoustic guitar. But tweeters sound horrid with a heavily distorted electric guitar tone, explaining why guitar amps don't have tweeters.

Going from 500w to 650w won't make any difference. Depending on the tuning frequency of the cab chances are that the amp is putting out [i]less[/i] power at 40-45 Hz than at 50-55Hz, because the impedance will probably be higher at 40-45Hz than 50-55Hz. Excursion with equal voltage input is probably considerably higher at 40-45Hz than at 50-55Hz, and that's the likely source of the problem.

[quote name='TheRev' timestamp='1508663331' post='3393570'] its a BigE/MAS45, which has pretty high excursion drivers. [/quote]Long excursion maybe, but they're still only 5 inch drivers. Four of them have less cone area than a single ten.

[quote name='TheRev' timestamp='1508592587' post='3393164'] Will I even notice the difference between 500 and 650w? [/quote]No. You need to double the power to get 3dB of additional headroom, which isn't all that much. Besides, nine times out of ten what you describe is caused by your speakers running out of excursion capacity.

After all the toil and trouble you Brits went through to defeat Napoleon you go and adopt his system of weights and measures, and relegate good King Henry VII to the dust bin. What's next for you? Drinking cold beer?

Obviously? Watch this: https://www.youtube.com/watch?v=YFKT4jvN4OE&feature=youtu.be

[quote name='radiophonic' timestamp='1507814958' post='3388157'] Fender Performer Cab. 4 x 10. 150W Apparently. [url="https://www.musicgoround.com/p/640363/used-fender-performer-cab-410-guitar-speaker-cabinet-4-x-10"]https://www.musicgor...-cabinet-4-x-10[/url] [/quote]The drivers are Eminence, produced in the 14th week of 1987. The only 4x10 Fender produced in 1987 was the BXR410 Bass. What you appear to have is a Dual Showman 'Wedge' 412 guitar cab.

The standard corner radius in the US is 3/8 inch. You don't need a gauge to measure it, just a ruler and a straight edge. Place the straight edge on one surface, extending beyond the joint of the two panels, use the ruler placed on the intersecting surface to measure the distance from where the chamfer begins to the straight edge.

Since it's sealed it may be a guitar cab.

[quote name='Jus Lukin' timestamp='1506894734' post='3381909'] Just to be clear, any crossing over (crossovering?!) or signal splitting would be for creative purposes rather than fidelity- say, a clean, deep, compressed signal on one channel, and a gnarly, bass shy drive on the other. [/quote]For that purpose what works best is a bass cab and head paired with a guitar combo.

[quote name='Jus Lukin' timestamp='1506867776' post='3381613'] I'd also like to run split signals, and setting the cab handling the highs nearer head height makes sense to me. [/quote]You only want to do that with cabs specifically designed for that purpose. PA cabs are, bass cabs are not. I'd no more mix cabs than I would a 50 year old single malt with diet coke. Pick the cab that sounds best to you, if one's not enough use two, but keep them the same.