High efficiency horn speaker amp question

[morricab]

tramping with 3 pairs of 50kg dual chassis monos would impress even my wife.......or not.....

You could use smaller amps when triamping, no? less power per amp would be needed...or perhaps your amps are like my Aries Cerat (70+KG) where the weight is not all about the power...

 

[christensenleif@msn.com]

single 300Bs with proper powersupplies

 

[Hear Here]

Do you need the same power or even the same amp technology when powering 2 or 3 sections of your speakers? I see no reason why you should. My horn speakers are happy for the mid and top horns to be powrered by a 6 watt SET amp but the bass is driven by 1000 watts of Class D.

ATC active speakers use 3 amps within the enclosure (of the ATC50) and these amps are 50, 100 and 200 watts. All the same technology but powered to suit the demands of the different drivers. I would suggest that perhaps one should choose cables to suit the frequency range each driver is handling unless the amps are within the speaker enclosure.

 

[christensenleif@msn.com]

I know all about mixing amps on speakers and started my horn career with Avantgarde Trio
the bass never blended in properly
in 2012 after 12 years I ditched them and started on my present all out approach
just out of sheer praciticality I use my Holton based Tower of Power amps on my sub horns, but that is below 75 hz after all....If I could I would have used tubes there too...

 

[Atmasphere]

You need tubes with horns.

I've not found this to be true. But you do have to be careful, since so many solid state amps make higher ordered harmonic distortion, in small amounts of course. But the ear doesn't care about that (its very sensitive to the higher orders) and interprets that distortion as harshness and brightness which is very easy to hear on horns. But not all solid state has this problem.

I know all about mixing amps on speakers and started my horn career with Avantgarde Trio
the bass never blended in properly

The problem with getting the bass to blend is the crossover point. IMO the Avantgarde subs cross over too high (about 200Hz IIRC) making a blend very difficult.

 

[Tim Link]

Hello,

From conventional High Amp world, I’ve a question regarding the relationship between high sensitivity/efficiency and amp power.

For example, in case of high efficiency horn speakers that can be easily driven by 12w tube amp,

SS (Pass Int 25) vs SS (Pass Int 60) would NOT make difference?

Or does still Int 60 make better sound?


I’m in a small room so I figure out that I’m good with Class A 30watt for most speakers, but

I heard that it’s always to have more power in the box to create deeper / wider spacial sound.


How about horn speakers?

Please consider that I’m new to this and be gentle

If you're just driving the horn and it's highly efficient - not a hybrid horn with a direct radiator bass unit and a passive crossover, it seems the need is for an amp that provides very low noise at relatively low output levels. More power won't hurt but I wouldn't trade it for better performance at low power. Most amps have an increasing signal to noise ratio as output goes up because the background noise level tends to stay constant regardless of power output until the amp reaches it's limits and starts to distort. That starting noise level needs to be lower for a horn, and I assume that it's easier to achieve with an amp that doesn't have to put out as much power. I don't know much about amplifier design, but I wonder how an amp specifically designed to run a high efficiency compression driver in an active setup would be different in design than one built for more general, lower efficiency speaker use. Any amp designers out there?

 

[christensenleif@msn.com]

I've not found this to be true. But you do have to be careful, since so many solid state amps make higher ordered harmonic distortion, in small amounts of course. But the ear doesn't care about that (its very sensitive to the higher orders) and interprets that distortion as harshness and brightness which is very easy to hear on horns. But not all solid state has this problem.


The problem with getting the bass to blend is the crossover point. IMO the Avantgarde subs cross over too high (about 200Hz IIRC) making a blend very difficult.

with the AG Trios I hipassed subs at 130 to meet the midbasshorn rolloff
present subhorns at 75

 

[Bjorn]

Class D here sounds great with horns Clean, open, detailed, high resolution, etc.

It's revealing but if your system can't take that, it's basically revealing flaws that should ideally be corrected IMO. Adding distortion and a less open sound in order to cover up other flaws doesn't give the same end result in my experience.

 

[Hear Here]

with the AG Trios I hipassed subs at 130 to meet the midbasshorn rolloff
present subhorns at 75

130 Hz for Trios is still far too high. Even with Duos, it's about 140 Hz for good blend between their much small mid horn to the bass. Trios are reported to be best set up with about 80 Hz crossover. The User Manuals are just wrong in my (and others) opinion regarding XO frequencies throughout the Uno, Duo, Trio range. Also worth trying is to connect the sub out-of-phase compared with the horns. There is far more electronics in the path to the sub drivers so phase is best experimented with. Perhaps you never needed to ditch your Trios . Did you get Jim Smith to help set them up?

 

[Atmasphere]

Most amps have an increasing signal to noise ratio as output goes up because the background noise level tends to stay constant regardless of power output until the amp reaches it's limits and starts to distort. That starting noise level needs to be lower for a horn, and I assume that it's easier to achieve with an amp that doesn't have to put out as much power. I don't know much about amplifier design, but I wonder how an amp specifically designed to run a high efficiency compression driver in an active setup would be different in design than one built for more general, lower efficiency speaker use. Any amp designers out there?

There are. The gain issue is very real; amps of traditional design that make 200 watts or more often have 30-35 dB of gain too, because its expected that the amp will be driving a speaker that might only be 89 or 90dB. You need that extra gain so that the preamp isn't being pushed to its limits.

Some SETs have as little as 15 dB. We solved this problem with our amps (which hnormally have about 24dB of gain) because our gain stage is a differential cascode; so we make a little octal plug that is substituted for a tube in the voltage amplifier, converting the differential cascode to a straight differential amp. This reduces the gain to about 15 dB making it nice and quiet on horns.

Essentially since speakers vary over a 20dB or more range, amps are the thing that usually have the different amount of gain, so the gain of preamps can be fairly consistent. IOW you should be able to use a Dynaco PAS3 in a system with horns or Magnaplanars, with the volume control in about the same place.

Trios are reported to be best set up with about 80 Hz crossover.

Actually that's true with most subs- cross them over below 80Hz and they are far less likely to attract attention to themselves.

 

[LL21]

...Actually that's true with most subs- cross them over below 80Hz and they are far less likely to attract attention to themselves.

Interestingly, I have had a Velodyne in my systems since 1993...upgrading models over time. Even when I had Celestion SL6si and then SF Guarneris...I still dont think I crossed over at 80hz, preferring to have a gap/hole than the 'bleeding over bass'...I think I tended to get down with those around 55hz+.

And today with the big Wilsons, the sub really focuses on everything below around 37hz or so.

 

[Tim Link]

There are. The gain issue is very real; amps of traditional design that make 200 watts or more often have 30-35 dB of gain too, because its expected that the amp will be driving a speaker that might only be 89 or 90dB. You need that extra gain so that the preamp isn't being pushed to its limits.

Some SETs have as little as 15 dB. We solved this problem with our amps (which hnormally have about 24dB of gain) because our gain stage is a differential cascode; so we make a little octal plug that is substituted for a tube in the voltage amplifier, converting the differential cascode to a straight differential amp. This reduces the gain to about 15 dB making it nice and quiet on horns.

Essentially since speakers vary over a 20dB or more range, amps are the thing that usually have the different amount of gain, so the gain of preamps can be fairly consistent. IOW you should be able to use a Dynaco PAS3 in a system with horns or Magnaplanars, with the volume control in about the same place.


Actually that's true with most subs- cross them over below 80Hz and they are far less likely to attract attention to themselves.

Thanks! Are there solid state amps with lower gain?

 

[Atmasphere]

Thanks! Are there solid state amps with lower gain?

Of course! If you're working with horns, Nelson Pass makes the First Watt amps, some of which have almost not gain at all. Some class D modules are available without buffer input circuits (I think the Hypex is an example) and so have low gain, about 15-17dB. They are a bit hard to drive in this state, but its not that hard to come up with a buffer that ameliorates the low input impedance but otherwise has no gain. That would be more of a DIY project though. I'm certain other examples are out there.

 

[Hear Here]

Actually that's true with most subs- cross them over below 80Hz and they are far less likely to attract attention to themselves.

The Avantgarde range use a "sub" as part of their 3 or 4 way system, so the sub has to provide all the frequences below the level that the mid-range horn can provide. In some AG speakers, this is in the region of 170 Hz, so AG's "subs" have to be set much higher than subs that are added to conventional speakers. The Trio, being a 4 way system with a very large lower-mid horn is the only model in their range where the XO can be set as low as 80 Hz. Setting a Duo or Uno sub to 80 Hz would result is a big gap in the frequency range offered by the system as a whole.

 

[Hear Here]

Thanks! Are there solid state amps with lower gain?

Better still - some have user adjustable gain. Accuphase amps usually have a front panel switch offering 4 settings (up to -12dB), GamuT amps have internal dip switches offering 4 levels (up to -14dB) and the Benchmark amp has a rear switch offering 3 settings. These are great if you use high efficiency speakers that need less gain but greater signal to noise ratio.

 

[Tim Link]

Of course! If you're working with horns, Nelson Pass makes the First Watt amps, some of which have almost not gain at all. Some class D modules are available without buffer input circuits (I think the Hypex is an example) and so have low gain, about 15-17dB. They are a bit hard to drive in this state, but its not that hard to come up with a buffer that ameliorates the low input impedance but otherwise has no gain. That would be more of a DIY project though. I'm certain other examples are out there.

Thanks much! That's clued me in a bit.

Better still - some have user adjustable gain. Accuphase amps usually have a front panel switch offering 4 settings (up to -12dB), GamuT amps have internal dip switches offering 4 levels (up to -14dB) and the Benchmark amp has a rear switch offering 3 settings. These are great if you use high efficiency speakers that need less gain but greater signal to noise ratio.

Great info! I'm going to start looking into options. My tweeters hiss a bit. It's nothing terrible but one of the few things I have to complain about, and something one other person who's listened to my system has noticed.

 

[Bjorn]

A brand name I represent (Vera Audio) have gain adjustments on the power amplifiers. Gain can be adjusted with accurate 3 dB steps and lowest gain setting is 12 dB.

 

[Hear Here]

Great info! I'm going to start looking into options. My tweeters hiss a bit. It's nothing terrible but one of the few things I have to complain about, and something one other person who's listened to my system has noticed.

Tim - There are more low powered amps that are suitable for horn speakers than might be expected. You show no "Signature" with your equipment listed so I'm wondering what speakers you have and which amplifier is generating the hiss you mention.

I've tried many SS amps with my 104 and more recently 107 dB speakers and found several that are dead silent irrespective of their gain. My present amp is 200 watts, but chosen not for its "on paper" suitability for my speakers, but for its sound and features. I wonder if the hiss comes from something before your amp. Peter

 

[marslo]

with the AG Trios I hipassed subs at 130 to meet the midbasshorn rolloff
present subhorns at 75

I just start my journey with Trio LE and bass integration.
As I am of the opinion that subs 231 XD are not up to the level of Trios performance and I have no space for basshorn in front of my listening chair I decided to go the my own way with REL subs which are the first choice for several Trio owners . Yesterday I installed two Carbon Special REL subs and tried to find the proper blend of the placement, crossover and gain. The amp in Carbon Special is 800 W class D and the crossover range from 20 to 120 Hz , Trios roll- off at 100 Hz according to the specification.
Whilst the auhority, articulation and energy of 20-30 Hz range is obvious I am very far from the integrity and the seamless blend.
If do not succed with REL will try to find the subs made on order , I follow your experience with a lot of interest.

 

[Mikem53]

Thanks! Are there solid state amps with lower gain?

The First Watt SIT3 has only 11.5 db of gain.