What are objective standards of good speakers for live sound

[Ken Beaumont]

My only criteria are "Do I like how these sound" and "Is the price what I want to pay?". I grew out of my audiophile stage in 90's. I was constantly buying high end stuff. There will always be something out there slightly better with an A/B comparison. Right now I'm really happy with my TurboSound systems ip300 for monitoring and two iP1000's and an 18 inch sub for the PA. At this point "why change?" it works so I am going to make sure I get most money back from my investment.

[ihavezippers]

Thanks Al Quinn, this is what I was wondering-whether the hiss I heard in Daves TT08AS was unique to those speakers (Dave mentioned potential electric issues and that they needed service for other issues, plus were more than a couple years old) or whether this is present in all TT08AS. No one accepts returns on new TT08As bc RCF doesnt accept returns-big gamble for such expensive speakers.

 

I did not hear a comparable hiss on the K8.2, whether low or moderately loud volumes. Granted, I was listening at Guitar Center with a lot of ambient noise (in contrast to Daves quiet studio).

[Al Quinn]

Yeah, I had them setup today while prepping for tomorrows gig and remembered your post. So I thought it would be helpful to share what I heard.

 

I dont think the level of hiss I hear would be audible in the GC environment. Ive actually never heard the hiss on a gig and only use the speakers at home when prepping equipment for a gig which isnt very often (i.e., I was checking out Keyscapes C7 soft piano which sounded glorious though the TT08As!).

[Reezekeys]

I hear hiss from my K8s when I have the input pad set to mic level. Of course, in that position I'm getting way more gain than I need, so by the time I back off the level control to the point where my laptop's headphone output isn't overdriving the K's input stage, the hiss is reduced and completely inaudible while playing. I haven't used this setting since I stopped playing super-loud wedding gigs! With the switch set to line level and my K's input control at max (+10db), I have enough volume to cover any medium-level jazz gig with drums, and zero hiss at any volume level.

 

It looks like the TT08 has a different approach to its input gain staging or in the way it's marked on the rear panel, with a level control that ranges from infinity to +4 to a "max" of -2db. It's a little above my pay grade to compare that with the K's controls. The K is marked with a range of infinity (off) to +10 db of gain, with a detent at 12 o'clock (0db or unity). I'll go out on a limb and say that the K might be a better option if you're connecting a low-line-level source directly to the speaker and need more input gain to get the maximum clean output. The TT08 would probably need a separate preamp to reach full rated output - not to mention that it has only XLR connectors, while the Ks have combo connectors. I'm sure Al or Dave will correct me if I'm wrong about any of this!

[Stephen S]

The TT08A does not have a full mixer section to it, and does not include a mic preamp. This is typical for pro products. I can't say for sure, but judging by the way the input control is labeled, I'm guessing that it probably has about 36 dB of gain or so through the electronics. Again - this is not uncommon. However, it does mean that it could be difficult to drive it to full output from a keyboard without having an intermediate mixer in the signal chain. Of course, this depends on the specific keyboard, how hot a signal it puts out and whether the output is balanced or unbalanced.

[Reezekeys]

I do understand that the TT08 is not aimed at a keyboard player that wants to simply plug the outputs of his or her keyboard directly into the speaker.

 

I was a little confused by how the gain control is marked... starting at infinity, then +4, then -2 at the end of its clockwise travel. It appears that those markings correspond to the nominal level of the signal going into the speaker not the amount of gain that the circuitry inside the speaker is applying to the input signal. A -2 signal would need more gain to get the same acoustic output as a +4 signal. Maybe I'm wrong, if I am then color me very confused. I do understand that this control does apply gain! It's only the way it's marked that's different on my QSC, the markings tell you how much gain is being applied.

 

In my case, I appreciate the ability to not have to deal with an extra mixer or preamp with the associated cabling and power supplies. I use a laptop setup so I mix and apply eq in the box. I like that I can plug a cable directly from the 3.5mm headphone outputs of my MacBook Pro into my K8s. The headphone output is typically hotter than consumer line level though perhaps not what one might see from a professional +4 output. As long as you can drive a speaker to a level sufficient for your gigs, staying as far above the noise floor of your electronics as possible, while not overdriving any stage of your amplification and leaving some headroom for peaks (iow, proper gain staging!), it's all good!

[Stephen S]

I agree that it is a bit confusing. The knob is labeled "sensitivity", which can be interpreted as "how much signal does it take to drive the speaker to the specified output level?" One would need to review the manual to know what level is specified as it relates to sensitivity.

 

With the knob set all the way to the left, the speaker is off so you would (in theory), need an infinitely large signal to drive it to the specified output level. Turn the knob clockwise to the 3:00 position;the printing on the panel indicates that you would need a signal of +4 dB (presumably dBu) to drive the speaker to the specified output. With the knob all the way to the right, the sensitivity is at maximum and so a signal of -2 dB would drive the speaker to the specified output.

 

 

[Al Quinn]

As long as you can drive a speaker to a level sufficient for your gigs, staying as far above the noise floor of your electronics as possible, while not overdriving any stage of your amplification and leaving some headroom for peaks (iow, proper gain staging!), it's all good!

Yeah, that's exactly it Rob.

 

I've plugged my keyboards directly into the TT08A inputs many times and have never run out of headroom. Unlike other power speakers I've had, the TT08As remain super clear even at loud volume. Like I said previously the hiss we're talking about is so low that I don't hear it at all on a gig. I'm happy

[Al Quinn]

I view the knob on the back of the TT08A as a volume knob because it adjusts the volume when I turn it. Never gave it more thought than that. Never felt motivated to read the manual because it does what I expect it to do. Is there something more I should know?

[Reezekeys]

I agree that it is a bit confusing. The knob is labeled "sensitivity", which can be interpreted as "how much signal does it take to drive the speaker to the specified output level?" One would need to review the manual to know what level is specified as it relates to sensitivity.

I did search for and look through the manual. Unless there is a different one I missed, this is about the barest-bones manual I've ever seen for a product which makes sense since the intended market is audio sound pros who don't need much explanation. But if there is a published spec somewhere that actually tells you the amount of gain the TT08a's input section provides, I didn't find it.

 

https://www.gtaust.com/downloads/tt08-a-manual.pdf

[Reezekeys]

I view the knob on the back of the TT08A as a volume knob because it adjusts the volume when I turn it. Never gave it more thought than that. Never felt motivated to read the manual because it does what I expect it to do. Is there something more I should know?

I would guess "no"!

 

An input control is pretty self-explanatory. The only question might be for someone considering buying one of these. If it were me, I'd want to feel assured that my MBP's headphone output could comfortably drive the TT08a to it's full output. I don't think ART is concerned with guys like me though, and I can't blame them we are probably a very small portion of their target market, if they're even aware of us at all.

[Al Quinn]

Rob, why is it important to drive the TT08A to it's full output if it's as loud as I need it to be? I just got back from a jazz quartet gig where I plugged the left and right outputs of my CP4 directly into a TT08A each. It sounded great and was loud enough.

[Reezekeys]

Al, I have no way of knowing if a TT08A will be as loud "as I need it to be" until I try one. Even if I never use it at full output, I would like to know it's capable of getting there with what my MBP feeds it. Just last night I played a jazz gig with Nussbaum and Chip Jackson, and those guys were hitting very hard! At a place with tile floor, low ceiling and in a corner with large windows. I had my volumes set to almost max which I hardly ever do (I had my K8s set to line level, vs mic level which I can't do right now). I had just enough clean volume with the headroom I needed. Any louder and it would have been a problem.

 

Though I don't enjoy playing loud, there was nothing I could do. I think it's reasonable to expect that I can get those levels if I have to even though I might not want to!

[Al Quinn]

Cool gig Rob! Yeah Adam N. certainly kicks the band into high gear. Saw him a couple of times with the Micheal Brecker band a few years back -- once with Kenny Kirkland and another time with Joey Calderazzo. Fantastic drummer, awesome band!

[Reezekeys]

Yea, playing with Adam is a rare treat for me these days. We go back to 3rd grade! Having Chip there - the guy that played bass with Elvin Jones for a few years - was the icing on the cake. I got my ass kicked, in a good way!

 

As far as the TT08s, what I wrote is pure conjecture since I have no plans to switch from my Ks. Some day I might play through a pair of TTs and regret that I didnt check them out sooner - but for now Im happy with my Ks, so for my wallets sake I prefer to stay blissfully ignorant!