Bill Fitzmaurice

47 minutes ago, Phil Starr said:

Can you clarify the speakers in the video aren't the Beta 12A's but the BP122's which are at least designed specifically for bass. Are you retrofitting the Beta's?

Neither of those are 200 watt, so I suspect those in the video are B102 or BP102. The magnet in the video also looks too large for the frame to be a twelve. It's true that one doesn't need a 32Hz F3 for low B, no more than does anyone need a 41Hz F3 for low E. But low B is still more demanding than low E, so I'd want at least 6mm xmax for low B use. 6mm xmax is usually going to cost more, but my philosophy is buy once, cry once.

For -3dB at 40Hz would require an internal box volume of 300 liters, exclusive of the space taken up by the port and the drivers. You don't necessarily have to go that low, a 50Hz F3 from a net box volume of 200 liters would suffice. But with less than 200 liters the low end would fall off rapidly. There's also the matter of the 4.4mm driver xmax. That's adequate for the most part with a low E, but not with a low B.

That's ported. Measuring frequency response is done with software, like HolmImpulse, and a USB measurement mic. The Beta 12 is an entry level driver, so whether it's adequate for your needs only you can say.

20 hours ago, BassmanPaul said:

You can get ground lift adaptors to take care of that problem. They are easy to make too.

With a proper balanced interconnection there's no need to lift the ground, that's one of the advantages of balanced. That said, not all devices are correctly configured. Have a look here, scroll to page 216.

https://www.yumpu.com/en/document/read/25666510/ranenote-collection

There's no point to bi-amping similar speakers. The difference in the low frequency limits would have to be close to two octaves to make it worthwhile.

1 hour ago, Phil Starr said:

Someone will say this so I might as well be the first. It isn't all about the watts.

+1. One can be perfectly fine with a 30 watt Ampeg B-15. One thing you can be sure of with respect to watts: the more someone dwells on their importance the less they understand about amplification. They probably can't even recite Ohm's Law from memory.

23 hours ago, AndyTravis said:

Ha, no way…

 

American.

 

and 2 fans.

Assembled in the US from components sourced in Asia. That's not the same thing as made in the US, not that anything is, any more than is anything made in GB.

On 15/02/2022 at 19:13, Downunderwonder said:

The chest cavity getting a tactile push is centered at 80hz. Is that what you are after?

Maybe. The problem when you use non-specific subjective terms is that there's no real definition, and therefore no agreement, on what it means. That greatly increases the difficulty of realizing whatever it is that you're trying to get.

48 minutes ago, BassmanPaul said:

Warning about the guy got me canned from Talkbass

And the downside? 😊

That had little to do with mineral rights, which American and other companies can and do get from the Greenlandics. It had to do with the Northwest Passage. Thanks to the global warming that Trump labels as a hoax it's gone from 19th Century fantasy to 21st Century reality.  In theory whoever controls the sea lanes within Greenland's territorial waters would have a strategic and economic advantage as more and more commerce goes through those waters from Asia to Europe. As usual Trump didn't think it through. It never occurred to him that the inhabitants of Greenland wouldn't go for it, even if the Danes did. If there's a change from the status quo for Greenland, currently an semi-autonomous possession, it will be to full fledged nationhood. It wasn't the most harebrained idea Trump ever had, but that list is a very long one.

If you're familiar with the innards of a vintage valve amp you've got perfboards that components are mounted to, with discreet wiring to the valves, pots, transformers, jacks and so forth. Even if the perfboards were loaded with their components in Asia, probably Viet Nam, that would still leave a lot of wiring to be done. Making a big deal about them being hand wired is advertising blather, because that type of construction can only be hand wired.

It's a completely different form of construction from circuit boards, which can be configured so that all the components, including the pots, jacks, valve sockets and power supply, are directly soldered to the boards, usually via wave soldering. In some cases there's only one board, so there's very little plugging in to do.

Without measured response charts SPL ratings are worthless. The figure could be a broadband average, it could be at the highest point of the curve. What you can assume that it's not is the SPL at 80Hz, which is where bass cabs should be rated.

Assembled in the USA means assembled from parts made in Asia. That applies to just about everything these days.

Despite the rare earth name neodymium isn't rare and it isn't all that difficult to refine. China is the main producer, for the same reasons China is the main producer of just about everything. The Chinese decided to take advantage of their near monopoly and jacked up the price. In response other countries have ramped up their mining and refining. The US is predicted to exceed Chinese production within the decade, while Australia, India and even Greenland are stepping up production. As for its use in the loudspeaker industry, that's a mere drop in the bucket. The main consumers are the auto industry for use in motors for electric vehicles, and the wind power electric generation industry for use in generators.

Double post, tried to delete the second one, I guess this forum software doesn't have a provision for that.

The clip indicator is probably reacting to the in initial attack. Since it's a power amp, not an instrument amp, the indicator is probably calibrated with the expectation of the signal being compressed.

Your 60s unit was hand wired too. 😉

9 hours ago, prowla said:

Linn Isobariks are one of the most regarded Hi-Fi speakers; they're not small, so the isobaric principle wasn't used to save space.

If they weren't isobaric they'd be even larger. They may not seem small today, but they were by the standards of their time. This is a quote from the Linn product information sheet:

Each speaker has two of each drive unit fitted – i.e. two bass, two mid and two treble. The second bass unit is hidden inside the cabinet, behind the visible bass unit and this forms the basis for our patented Isobarik equal-pressure bass system. This means that the front speaker behaves as if it is in a much bigger enclosure.

On 18/02/2022 at 14:36, JPJ said:

A lot of venues these days have in-house PA systems and at least one of our local venue’s has a PA with way too many subs mainly to satisfy the venues other use as a nightclub. Given that these venue systems are presented to the visiting FOH engineer as ‘tuned’ systems, the first time the engineer here’s the system with a crowd in the room will be show time. 

Understood, but it shouldn't take him more than a song to sort it out, if not in sound check. IME the problem is sound men who don't know what they're doing, and I've seen them from pub gigs to stadiums. The best FOH engineers I've worked with tended to be bass players and recording engineers, if not both.  One I knew who was particularly good, he was working with 'Journey' when I met him, would automatically high pass the bass at 60Hz, knowing that doing so would make the bass through a monster PA still sound like a bass. If they all did so it might make going to concerts an enjoyable experience again. 

That's what happens to a sine wave, but music doesn't consist of sine waves. With music content what happens is that whether it's an amp, a stomp box or a speaker there comes a point where there's not enough rail voltage and/or driver excursion to go any louder in the low frequencies, so they don't get louder with additional signal applied. The midrange and high frequencies do get louder, and that changes the tone. When you do that using a Les Paul through an AC30 and Greenbacks that tonal change is for the better. When it's a PBass through an SS amp and tweeters it's like nails on a chalkboard. This is why you shouldn't use tweeters if you employ distortion, and why AC30s don't have tweeters at all.

1 hour ago, Dan Dare said:

 Amplifier clipping causes a similar effect. It effectively means the cab is sent a square wave

Not exactly. Clipping doesn't send a square wave, no more than a pristine signal sends a sine wave. In all cases what's sent to the speaker is a complex wave form. What differs when the signal is clipped is that there's a lot of midrange and high frequency harmonic content present that's not in the original signal. With bass that can sound nasty, especially if you have tweeters. With guitar it's the Holy Grail.

1 hour ago, Lfalex v1.1 said:

Maybe it's the various amps' Damping Factors being wildly different.

Power makes the drivers move. 

A higher damping factor stops them more swiftly once the signal has stopped.

That's a straw that an oddiophile or amp salesman might grasp, but unless you're running 50 meter or longer speaker cables damping factor is a non-factor. Besides, the damping factor of valve amps being much lower than SS it wouldn't explain the OPs situation. However, while his YBA-200 amp doesn't have Fender/Marshall circuitry it does have the same style of passive tone controls, which along with natural compression and high passing leaves me to believe that's the difference. It's not without good reason that heavy iron valve amps remain the standard for tone, if you can manage to lift them, or even better have roadies to do it for you.

If his Traynor is a Fender copy (that's how they started off back in the 60s) the passive EQ can't give much bass boost, while significant high passing is built in.

8 hours ago, Dan Dare said:

If it doesn't happen with the more powerful amp, that would suggest clipping to me. If you are boosting the lows especially, the amp could simply be running out of steam. The Traynor, being all valve and with a meaty power supply, can simply deliver more sustained current than the other two.

Knowing what model Traynor would help, but it's certainly possible. Another consideration is that the natural compression of the valve amp is the difference. That compression is what gave rise to the valve watts versus SS watts nonsense, which gave rise to the even more nonsensical TC watts.

I've experienced that a lot, starting with Ringo/Sheila E/Greg Lake 20 odd years ago. It wasn't their fault, it was the PA FOH engineer. The EQ was so AFU that whenever Greg hit a note from C on down it drowned out the entire band, but when he hit a higher note the bass disappeared entirely. When Ringo went for a stint on his kit the kick was so loud that even back on his riser he felt it, and told the engineer on mic in the middle of the song to turn it down. Gosh awful.

There should be a special section of hell where idiot sound men who have no idea what bass and kick drums are supposed to sound like should spend eternity: polka music 24/7/365.