How to set up system regarding Pre / Power amp?
Discussion
You say that the room is for music production rather than Hi-Fi, and you've been using an integrated Hi-Fi amp by Harman Kardon to provide power the speakers. However, you've also got bits of Hi-Fi gear in there too. A turntable + phono pre-amp and maybe other bits of Hi-Fi gear. In reality then it's a stereo system with what, a keyboard or DAW computer, mixer + maybe mics?
You've changed to a Yamaha PA amp, something along the lines of this P7000s or similar, but now find yourself short of a way to handle the various inputs.
Yes, what you have is a power amp. As good as the Yamaha PA might be, it's not the same as a Hi-Fi power amp. If your goal is fidelity, then you might have taken a wrong turn. The Yamaha should provide far greater power which means better control over the speakers and less compression/better dynamics when you're playing fairly loud. Harman Kardon amps have a bit of a reputation for decent power output too, but it won't match the scale of the Yamaha. Where it may be better though is with greater transparency within its performance envelope.
The Yamahas are good, solid, dependable power amps for running modest PA systems. The sort of speakers it would be partnered with would be equally robust. By that I mean they could stand up to some ham-fisted abuse. Think 'karaoke system in a pub/bar' where you have three drunk girls trying to belt out 'I will survive' by Gloria Gaynor. Hi-Fi tweeters and woofers get destroyed by that, so PA speakers are built with thicker tweeter diaphragms and heavier-duty voice coils all round. They won't let you hear the subtleties that Hi-Fi speakers can reveal, but they will survive all kinds of abuse. PA amps are generally built to follow suit.
Where I wouldn't expect to see these kind of PA amps is in an audio mixing suite. These are places where detail matters, so they use powered speakers (active monitors) very similar to Hi-Fi speakers (Focal Chorus 800V).
Anyway, back to your connection issue. If your mixer / mixing desk has enough spare inputs then you could use that. The benefit should be that the mixer output is balanced (3-pin XLR or balanced TRS 1/4" jack) and so should be the input to the power amp. This provides some isolation from RFI between the two. You'll still have unbalanced (RCA) connections in from your Hi-Fi sources though. You'll also 'lose' those inputs on the mixer which might be okay if you have a 24-channel Allen & Heath desk, but it's a bit more inconvenient with say an 8-way Behringer.
The alternative is indeed a Hi-Fi stereo pre-amp. The HK might be a model with pre-out connections, so that would do the trick, albeit taking up a bit of space and chewing through a few more Watts of power than the task requires. The alternative might be to sell to HK amp and replace it with a simple Hi-Fi pre-amp. Rotel has normally a good shout for this. They have decent phono stages and haven't been expensive as used buys. Some of the models are getting quite long in the tooth now though, so finding a good, unmolested example is getting trickier. RC-850, RC-970, RC-971, RC-960 and others. Prices are ballpark £80-£150 used.
You've changed to a Yamaha PA amp, something along the lines of this P7000s or similar, but now find yourself short of a way to handle the various inputs.
Yes, what you have is a power amp. As good as the Yamaha PA might be, it's not the same as a Hi-Fi power amp. If your goal is fidelity, then you might have taken a wrong turn. The Yamaha should provide far greater power which means better control over the speakers and less compression/better dynamics when you're playing fairly loud. Harman Kardon amps have a bit of a reputation for decent power output too, but it won't match the scale of the Yamaha. Where it may be better though is with greater transparency within its performance envelope.
The Yamahas are good, solid, dependable power amps for running modest PA systems. The sort of speakers it would be partnered with would be equally robust. By that I mean they could stand up to some ham-fisted abuse. Think 'karaoke system in a pub/bar' where you have three drunk girls trying to belt out 'I will survive' by Gloria Gaynor. Hi-Fi tweeters and woofers get destroyed by that, so PA speakers are built with thicker tweeter diaphragms and heavier-duty voice coils all round. They won't let you hear the subtleties that Hi-Fi speakers can reveal, but they will survive all kinds of abuse. PA amps are generally built to follow suit.
Where I wouldn't expect to see these kind of PA amps is in an audio mixing suite. These are places where detail matters, so they use powered speakers (active monitors) very similar to Hi-Fi speakers (Focal Chorus 800V).
Anyway, back to your connection issue. If your mixer / mixing desk has enough spare inputs then you could use that. The benefit should be that the mixer output is balanced (3-pin XLR or balanced TRS 1/4" jack) and so should be the input to the power amp. This provides some isolation from RFI between the two. You'll still have unbalanced (RCA) connections in from your Hi-Fi sources though. You'll also 'lose' those inputs on the mixer which might be okay if you have a 24-channel Allen & Heath desk, but it's a bit more inconvenient with say an 8-way Behringer.
The alternative is indeed a Hi-Fi stereo pre-amp. The HK might be a model with pre-out connections, so that would do the trick, albeit taking up a bit of space and chewing through a few more Watts of power than the task requires. The alternative might be to sell to HK amp and replace it with a simple Hi-Fi pre-amp. Rotel has normally a good shout for this. They have decent phono stages and haven't been expensive as used buys. Some of the models are getting quite long in the tooth now though, so finding a good, unmolested example is getting trickier. RC-850, RC-970, RC-971, RC-960 and others. Prices are ballpark £80-£150 used.
nuyorican said:
Primary speakers in use are Yamaha NS10 Studio and JBL 4311. The new (to me) amp is a Yamaha PC2002m, a lot of power but still not what I’d consider a PA amp.
No. I'd still consider the 2002 as a PA amp. It's a class A/B or B design looking at the weight and the age. IOW, this isn't a lightweight Class D. Given the design then, the power output at 240W/ch continuous into 8 Ohms with just 0.05% THD is not to be sneezed at. If this were running the NS-10M Studios they need 60W continuous as a guide, and 120W peak. The Yamaha delivers 4X that power level without breaking a sweat. The JBLs don't need much more; 75W continuous so 150W peak. The Yam is still 3X more powerful. (All at 8 Ohm) This is a slight case of over-bombing.
nuyorican said:
I think the mixing desk might be the way to go. Especially if it has two outputs to drive both amps and pairs of speakers. I’ll have to check when I’m next there.
You don't need dual outputs on the mixer. The 2002 has loop-through connectors for both the balanced and unbalanced inputs. You can run both sets of speakers simultaneously. Daisy-chain from the mixer to the 2002 to the other amp. Lucid_AV said:
No. I'd still consider the 2002 as a PA amp. It's a class A/B or B design looking at the weight and the age. IOW, this isn't a lightweight Class D.
.
Whilst the PC-2002M is, on paper, a professional amplifier, it's also superb-sounding hi-fi amplifier. .
Many Yamaha PA amplifiers and hi-fi amplifiers of this era actually shared internals, the most notable being the 101M (uber-rare, huge top end domestic power amplifier only ever sold in Japan) and the PC-5002M (moderately rare huge professional amplifier sold worldwide).
Deranged Rover said:
Whilst the PC-2002M is, on paper, a professional amplifier, it's also superb-sounding hi-fi amplifier.
Many Yamaha PA amplifiers and hi-fi amplifiers of this era actually shared internals, the most notable being the 101M (uber-rare, huge top end domestic power amplifier only ever sold in Japan) and the PC-5002M (moderately rare huge professional amplifier sold worldwide).
I'm a Yamaha fan. If it's anything like the DSP-A2070 and DSP-A3090 AV amps I've played around with then the power delivery will be deep and fathomless with moderate sized floor-standers and good stand-mount speakers. Not the last word in precision or detail, but lush and effortless. Many Yamaha PA amplifiers and hi-fi amplifiers of this era actually shared internals, the most notable being the 101M (uber-rare, huge top end domestic power amplifier only ever sold in Japan) and the PC-5002M (moderately rare huge professional amplifier sold worldwide).
nuyorican said:
Could you recommend some speakers that would be an ideal match for the Yamaha? I always have the option of carrying on with my current setup which to be honest, if it ain’t broke… Both sets of speakers driven by Harmen Kardon PM655VXI and selected by the handy speaker selection feature - A/B/A+B
The Yamaha was on my list of things I wanted and came up at the right price in the right condition. It might be better (and more fun) to add new speakers to it rather than try to shoehorn it into my current setup. As both my current speakers are kind of clinical monitors, it would be nice to have something vibey and fun to listen to. Decent bass is important as I mainly listen to dance music from the late 70’s to the early 90’s. Or maybe use the Yamaha to a big passive sub…
The room isn’t huge so I can’t get into PA gear. Plus, I don’t have tens of thousands to spend so nothing too new and esoteric.
Thanks again
The fact that the room isn't huge is the first thing I picked out. That, and the JBLs have an almost 12" bass driver, though it's actually driven full range. These two things make finding a fun speaker a bit of a challenge. Large bass drivers plus bass ports in a small room generally isn't a great mix. The room size can curtail the bass depth because the note's wavelengths are longer than the room. You're also sate relatively close to the node points in the corners where bass response gets very lumpy. The Yamaha was on my list of things I wanted and came up at the right price in the right condition. It might be better (and more fun) to add new speakers to it rather than try to shoehorn it into my current setup. As both my current speakers are kind of clinical monitors, it would be nice to have something vibey and fun to listen to. Decent bass is important as I mainly listen to dance music from the late 70’s to the early 90’s. Or maybe use the Yamaha to a big passive sub…
The room isn’t huge so I can’t get into PA gear. Plus, I don’t have tens of thousands to spend so nothing too new and esoteric.
Thanks again
Edited by nuyorican on Tuesday 23 January 09:57
Both the JBL 4311 and the Yam NS-10M Studios have very distinctive sonic signatures. From memory of the NS-10s from the '80s, they were thin and brittle sounding. IDK if later iterations tamed the treble and got a little extra bass. The JBLs I've never heard, but as I understand it they allow the bass driver to reproduce mid and some treble which is an odd choice. In short, if you're mixing for accuracy then there are better speakers. On the other hand, if you're just noodling around for pleasure, there are still better speakers.
For proper mixing duties then something from the range of active studio monitors from Focal, Adam, PMC or Genelec should be on your shortlist. Then playing for fun, maybe some used Tannoy Definitions - the standmount DC8 or the floorstanding DC10. They both have great foot-tapping ability.
Before you spend on speakers though, I'd be tempted to investigate acoustic treatment for the room. Bass traps for the room corners and ceiling/wall boundary points. Some absorption on the front and back walls, then a mix of diffusers and absorption to tame or soften the first reflection points. One the room is better able to disperse the acoustic energy then play around with the speaker position of the JBLs. I think they're meant to be flown, so pointing down at you from height.
Nearly all current speaker designs are bass reflex ported. We know why designers do this. It gives the bass an extra bump and it makes the speakers easier to drive. The problem is it causes placement issues. in the sort of average UK living rooms. There just isn't enough space for the speakers to get out of their own way. They end up too close to the rear wall, and so the boundary effect that bass reflex doesn't need then adds to bass boost from the port. The result is a boomy mess.
We could really do with getting back to infinite baffle (sealed box) loudspeakers. Given the same driver size, an IB speaker will produce deeper bass that doesn't hit the frequency brick wall that is the port tuning frequency of a reflex design. The problem is when speakers are measured in an anechoic chamber there's no wall behind an IB design, so the graph looks like there's no bass. The reflex speaker graph looks better, even though the bass isn't as extended and it will sound worse in real life unless positioned far enough away from a wall to balance the boundary effect. Ho hum.
What we're left with then - especially in the UK - are speakers with small mid/bass drivers 6", 5.5" and even smaller so that they don't provoke boundary effect too much. We could do with a new messiah of speaker design. A reincarnation of Edgar Villchur, he of Acoustic Research speaker fame.
The typical foam tiles are thin, and because of that they're only effective at higher frequencies. They work okay for killing the [i]tsk-tsk-tsk]/i] sound of slap echo, but they still leave a lot of sound energy bouncing around the room.
Finding out how effective any sort of treatment and even moving the speakers can be is relatively simple now. There are calibrated mics from Umik, Dayton, Earthworks and others for various measuring jobs. A simple Umik is perfect for acoustic measurement in recording studios and home music/cinema rooms. This USB mic can be connected to a laptop running some measurement software called Room EQ Wizard (REW). The software also includes a tone generator function, so it's the source as well as the recording device.
Calibrated mics are different to the standard versions in that they've been individually measured to great accuracy, and then a compensation file is drawn up to create a mic + file combo that results in a flat frequency response. The mic then becomes a reliable measurement tool. The calibration file for the specific mic is downloaded from the manufacturer or 3rd party calibration service website. It is tied to the serial number of the mic. Each calibration file is like a fingerprint; unique to its 'owner'
The resulting frequency sweeps will show the peaks and nulls where a combination of the room dimensions, mic position, speaker positions, frequency all interact. Playing around with things that can be varied such as speaker positions and room treatment will result in shifts in the graph. You can then decide if what has been done has been effective or not. A calibrated Umik is around £130. The software is free for personal use. Add a little cash for a mic stand and a long USB lead means you can be up and running for well under £200. This is a far better approach that throwing cash at room treatment products bought off the web with no real idea whether they make things better or worse.
You mentioned adding a passive sub in a previous post. I didn't reply to that specific point at the time because I thought you had enough to deal with. Now we've touched on room measurement then I can say that adding a passive without some way to blend it with the mains speakers will cause you more problems. Just the basic volume, phase and crossover controls are missing from a power amp + passive sub combo. You would need something like a MiniDSP box to get the sub to blend and time correctly. With a calibrated mic and REW software you could get really accurate results with any sub.
Finding out how effective any sort of treatment and even moving the speakers can be is relatively simple now. There are calibrated mics from Umik, Dayton, Earthworks and others for various measuring jobs. A simple Umik is perfect for acoustic measurement in recording studios and home music/cinema rooms. This USB mic can be connected to a laptop running some measurement software called Room EQ Wizard (REW). The software also includes a tone generator function, so it's the source as well as the recording device.
Calibrated mics are different to the standard versions in that they've been individually measured to great accuracy, and then a compensation file is drawn up to create a mic + file combo that results in a flat frequency response. The mic then becomes a reliable measurement tool. The calibration file for the specific mic is downloaded from the manufacturer or 3rd party calibration service website. It is tied to the serial number of the mic. Each calibration file is like a fingerprint; unique to its 'owner'
The resulting frequency sweeps will show the peaks and nulls where a combination of the room dimensions, mic position, speaker positions, frequency all interact. Playing around with things that can be varied such as speaker positions and room treatment will result in shifts in the graph. You can then decide if what has been done has been effective or not. A calibrated Umik is around £130. The software is free for personal use. Add a little cash for a mic stand and a long USB lead means you can be up and running for well under £200. This is a far better approach that throwing cash at room treatment products bought off the web with no real idea whether they make things better or worse.
You mentioned adding a passive sub in a previous post. I didn't reply to that specific point at the time because I thought you had enough to deal with. Now we've touched on room measurement then I can say that adding a passive without some way to blend it with the mains speakers will cause you more problems. Just the basic volume, phase and crossover controls are missing from a power amp + passive sub combo. You would need something like a MiniDSP box to get the sub to blend and time correctly. With a calibrated mic and REW software you could get really accurate results with any sub.
nuyorican said:
How is the beast?
Tell me, how do you set the volume controls in it? Do you leave them at a set position and control the volume via the preamp. Or get the best signal going in to it and then raise the volume pots on the Yamaha to suit?
I always followed the latter. I used to do a bit of DJ’ing so always considered gain staging. But that was when I was using integrated amplifiers. Is it different for power amps?
I keep falling over it now, though so I really do need to compose myself and sort it out, then either put it back into use or sell it.
As to the controls, when I used it, it was in a hi-fi setup with a preamplifier, so i just set the level controls to maximum and used the preamp volume control as normal.
Gassing Station | Home Cinema & Hi-Fi | Top of Page | What's New | My Stuff