A/B of Bose S1 Pro Plus vs DV Mark Little Jazz

[nevershouldhavesoldit]

Let's try this one more time.

Nominal mic level is -60 dBV. Instrument level is anywhere from -30 dBV to -10 dBV, depending on the specifics of the instrument (e.g. pickup specs). There's no standard "instrument level" per se. Line level in consumer electronics is -10 dBV. Pro equipment uses a different standard called dBu (which is independent of the load into which the signal is going), and the pro "standard" for line level is +4 dBu.

Reference voltages and dBV are calculated into a 600 Ohm load, while dBu are independent of the impedance being driven. These levels are peak levels before rated distortion (which is determined by the design of the device in use) is exceeded. Mic level is a few millivolts, instrument level is in the range of 100 to 200 mV peak, consumer line level is 0.314 V, and pro line level is 1.228 V.

I don't know where you got that 22 dB gain figure. Passive DIs turn unbalanced instrument level signals into balanced mic level signals. So a 150 mV signal from a guitar pickup (which is about -16 dBV) run into a standard passive DI will be converted to a mic level signal of less than 5 mV (-60 dB peak). There will be a significant drop in volume if you run the DI's output into the same input into which you ran the guitar itself because the signal level is much lower.

The mic preamp in a powered speaker is designed to accept a mic level signal and amplify its voltage up to line level so it can then drive the power output stage. Plugging a DI into the mic input on the Alto will give you excellent sound quality at the SPL you expect, because the mic preamp will boost the low signal coming from the DI to the level needed to drive the power amplification stages. If you plug a guitar directly into most mic preamp inputs, the sound will be too loud, distorted, and noisy because it's overdriving the mic preamp and the impedance match between source and input is poor.

There are a few mic preamps in today's equipment that can handle a guitar's signal, but this is unusual. Why (you may ask) is there a mic input on old guitar amps? In the old days (when I was a boy), the mic inputs on PA and guitar amplifiers were designed to accept crystal microphones, which had much higher outputs than today's microphones. They also had output impedances of 100kOhms or more. A guitar's signal was much closer to that of a crystal mic than it is to today's dynamic, ribbon, condenser etc mics. This is why I could (and often did) plug my guitar directly into the mic input of our high school gym's PA system. It's why there were mic inputs on old guitar amplifiers.

[rpjazzguitar]

Let's try this one more time.

Nominal mic level is -60 dBV. Instrument level is anywhere from -30 dBV to -10 dBV, depending on the specifics of the instrument (e.g. pickup specs). There's no standard "instrument level" per se. Line level in consumer electronics is -10 dBV. Pro equipment uses a different standard called dBu (which is independent of the load into which the signal is going), and the pro "standard" for line level is +4 dBu.

Reference voltages and dBV are calculated into a 600 Ohm load, while dBu are independent of the impedance being driven. These levels are peak levels before rated distortion (which is determined by the design of the device in use) is exceeded. Mic level is a few millivolts, instrument level is in the range of 100 to 200 mV peak, consumer line level is 0.314 V, and pro line level is 1.228 V.

I don't know where you got that 22 dB gain figure. Passive DIs turn unbalanced instrument level signals into balanced mic level signals. So a 150 mV signal from a guitar pickup (which is about -16 dBV) run into a standard passive DI will be converted to a mic level signal of less than 5 mV (-60 dB peak). There will be a significant drop in volume if you run the DI's output into the same input into which you ran the guitar itself because the signal level is much lower.

The mic preamp in a powered speaker is designed to accept a mic level signal and amplify its voltage up to line level so it can then drive the power output stage. Plugging a DI into the mic input on the Alto will give you excellent sound quality at the SPL you expect, because the mic preamp will boost the low signal coming from the DI to the level needed to drive the power amplification stages. If you plug a guitar directly into most mic preamp inputs, the sound will be too loud, distorted, and noisy because it's overdriving the mic preamp and the impedance match between source and input is poor.
.

Thanks for bearing with me.

The -22db gain figure is not in the manual. I found it on the Internet, which is far from a guarantee that it's correct. I should have noted the source.

[rpjazzguitar]

The Alto TS408 arrived, with the case badly cracked and stuff rattling around inside.

I bought from Guitar Center for home delivery, but you can return it to any GC store.

So, I did that. To their credit, there was no argument. I was concerned that they'd tell me to file a claim with UPS or something like that, but no. Instead, they issued a refund with zero hassle.

GC gets a bad rap from some, but, if you know what you want and they sell it, it's a very good option. Hard to beat a 45 day return privilege and the willingness to match any on-line price.

The salesman offered to order a new Alto TS408, but the cracked case had me wondering about case integrity. I'd have felt foolish if I got another one and eventually ended up with the same problem.

He checked, and found a JBL Eon One Compact in stock.

It was one of the units I had researched. It weighs about 17lbs, has multiband parametric EQ on each channel, a separate EQ for the master, and has a hi-Z input. Other features include FX, app control, master and channel volumes.

Initial trials were promising. I was able to get a pretty good guitar sound without any additional device between the pedalboard and the powered speaker. And that was without fine tuning the EQ. I'll try it in big band on Monday.

EDIT: Some of the on-line commentary early on focused on a problem with the power switch. I read that JBL has since solved it. Reportedly, there are ongoing issues with Bluetooth, but I haven't encountered them yet. The control functions work fine. Some posters complained about difficulty linking multiple units by bluetooth, which I'm not doing.

There were complaints about the app, but, so far, it has worked fine. Some of the functions seemed less than obvious, but once I figured out the layout and labels, it went well.

I was able to easily dial out any boominess in the bass using the channel EQ.

The unit features reverb, chorus and delay but there are no footswitches to turn them on and off, afaik.

Vocals sounded pretty good. Maybe without the full warmth of the Bose S1, but I might get there with the EQ options.

EDIT2: A/B against a Roland JC55 in the practice room. Both run flat. JC55 was noticeably better. JBL was in "usable, not optimal" territory. Next I have to tweak the EQ.

The channel EQ is done with the app. Six bands and you get to choose center frequency, width and boost. Lotta possibilities. Perhaps the reason why Bose did it with two band and presets. I think there are also presets in the JBL (and you can save patches, called snapshots), but I haven't explored them yet. It will be a while before I can do the definitive A/B comparison with the sound optimized on each device.