I don't believe it. I need more power?

[Irvrobinson]

I don't know what your average listening levels are, but mine are between 65 and 75 db.

Your average power output would be five to 10 times higher than on most systems if your estimate is correct and it possibly is, but I would expect it is nearer 5 watts. That pretty much fits with the data on those speakers in my view.

So now lets go to 80 db you need 50 watts, now go to 90 db and you need 500, now take it to 100 db and you need 1000 watts. So 500 per channel. If you wanted to go to 110 db which I would not advise would require 10,000 watts, 5000 watts per channel.

If you really are averaging 10 watts average, then those figures are 100 watts, 1000 watts, 10,000 watts and you can't even think of getting to 110 db.

Now thermal compression is a huge issue with all speakers. Just think how quickly a coil of wire heats up with those sort of powers. It is a fraction of a second. Pop and rock music is a huge challenge as the average power demands are so high. Just think how much heat a 25 watt light bulb generates.

Now as I explained with the use of 150 Hz passive crossover the inductors in series with those woofers, the inductors will heat quickly.

Lets put 1000 watts into your speaker, that is going to be 16 amps, the lions share is below 600 Hz, and an awful lot will be below 150 Hz.

Since we are discussing music being at high levels here, I was referring to very high average levels, like 90db, as one often hears with a live rock band. I'm estimating peaks were 12-15db higher than that. (For normal listening I'm in the high 70s / low 80s on average.) So we are discussing only "live music loud" scenarios. So ~90db is where I got the 8-12w estimate.

 

[TLS Guy]

Since we are discussing music being at high levels here, I was referring to very high average levels, like 90db, as one often hears with a live rock band. I'm estimating peaks were 12-15db higher than that. (For normal listening I'm in the high 70s / low 80s on average.) So we are discussing only "live music loud" scenarios. So ~90db is where I got the 8-12w estimate.

I bet you are using a lot more than 12 watts at 90 db, that is loud for an average listening level.

Lets say you are 9 ft from the speakers. From the data on your speakers, it would take 150 watts per channel to give you 93 db at 9b ft it is going to be 150 watts per channel, for 90 db 75 watts. So to get to 100 db would demand 750 watts per channel and 325 watts gets you to 97 db, which is very loud and about the power of your amp. Most domestic speakers are not designed to give levels in excess of 100 db at the listening position, unless they are highly efficient horn loaded ones like Klipsch.

Now you start to see the problem with rock music. Average levels are very high (bad for most speakers) and when you do get peaks, insane levels are called for.

Now take a huge score like the Mahler 5th symphony. Soft passages fall blow 50 db, average seems to be high sixties to 70 and the one loudest peak I clocked at 103 db. That is a very different situation and really requires a different design approach.

If you calculate the numbers out, that is going to be a lot of heat over time in the crossover components. For rock music it pretty much makes it imperative if you want a low crossover point to have an active speaker, at least if you play at the levels you are talking about.

 

[Irvrobinson]

I bet you are using a lot more than 12 watts at 90 db, that is loud for an average listening level.

Lets say you are 9 ft from the speakers. From the data on your speakers, it would take 150 watts per channel to give you 93 db at 9b ft it is going to be 150 watts per channel, for 90 db 75 watts. So to get to 100 db would demand 750 watts per channel and 325 watts gets you to 97 db, which is very loud and about the power of your amp. Most domestic speakers are not designed to give levels in excess of 100 db at the listening position, unless they are highly efficient horn loaded ones like Klipsch.

I use this web site to calculate peak sound levels:

Peak SPL Calculator

Using 83db/watt/meter, 450w (4 ohm rating), listening seat 12 feet from the speakers, and "near a wall" (because my speakers are about 4 feet from the walls), I get 104db peaks at my listening seat, which is just about right, according to my OmniMic readings.

FWIW, my speakers and listening seat are in an approximate 12 foot equilateral triangle, with the speakers about 4 feet from the back wall and 3 feet from the side walls. The ceiling height is about 18-20 feet, and the right side wall only protrudes about three feet.

 

[TLS Guy]

I use this web site to calculate peak sound levels:

Peak SPL Calculator

Using 83db/watt/meter, 450w (4 ohm rating), listening seat 12 feet from the speakers, and "near a wall" (because my speakers are about 4 feet from the walls), I get 104db peaks at my listening seat, which is just about right, according to my OmniMic readings.

FWIW, my speakers and listening seat are in an approximate 12 foot equilateral triangle, with the speakers about 4 feet from the back wall and 3 feet from the side walls. The ceiling height is about 18-20 feet, and the right side wall only protrudes about three feet.

I was giving you rough estimates, as it is hard to remotely factor in room gain, because losses and gains are so variable. But I was within 7 db of what you measured and I bet you are picking up rear wall reflections, giving you a bounce.

I would have thought that if you can reach 104 db where you listen, that is plenty loud enough. I would really doubt I have ever driven my rig beyond that region.

 

[Irvrobinson]

I was giving you rough estimates, as it is hard to remotely factor in room gain, because losses and gains are so variable. But I was within 7 db of what you measured and I bet you are picking up rear wall reflections, giving you a bounce.

Of course. You weren't aware of my configuration until I told you, and the web page I've referenced admits to making estimates and assumptions itself.

I would have thought that if you can reach 104 db where you listen, that is plenty loud enough. I would really doubt I have ever driven my rig beyond that region.

Me too. My level of surprise is what caused me to start this thread. For realistic, well-recorded R&R music loud peaks must be more important than I thought. It should be noted, however, that the Telarc recording I've referenced is quite unusual... a purist pop recording, if you will.

 

[DD66000]

I did not read/see what you have for room treatments. The deader the room, the more power is needed for a given SPL.
As to amps used with the Salon2. I've known people who were using Parasound JC1 mono amps (400w) and never ran out of power.

 

[Irvrobinson]

I did not read/see what you have for room treatments. The deader the room, the more power is needed for a given SPL.
As to amps used with the Salon2. I've known people who were using Parasound JC1 mono amps (400w) and never ran out of power.

I don't use room treatments at all. The wall behind the speakers is essentially uncovered glass that rises about 12 feet or so, the rear and one side wall are built-in book cases, the other side wall is mostly open into a large kitchen and eating area. The ceiling rises to about 18 feet or so, and on one side there's a second floor loft.

Seating is an over-stuffed leather corner sectional with a matching 4'x4' hassock. Wall-to-wall carpeting. So the upper part of the room is rather live, the lower part rather dead.

 

[DD66000]

I don't use room treatments at all. The wall behind the speakers is essentially uncovered glass that rises about 12 feet or so, the rear and one side wall are built-in book cases, the other side wall is mostly open into a large kitchen and eating area. The ceiling rises to about 18 feet or so, and on one side there's a second floor loft.

Seating is an over-stuffed leather corner sectional with a matching 4'x4' hassock. Wall-to-wall carpeting. So the upper part of the room is rather live, the lower part rather dead.

Sounds similar to a living room I had in the late '70s. It had a vaulted ceiling to about 14 ft to the peak, 13 ft from the front wall. At that point a wall dropped from the peak to the 8 ft level and then a flat ceiling for the rest of the length of the room. Plus a stairway on one side.
The result was NO bass what-so-ever, due to bad standing waves! So I bought what was probably the first consumer sat/sub system, JBL L212. Put the sub in the corner, and the bass was back.

With tall rooms, it seems to me, that it really can eat up the power required to drive a system. Especially when the speakers are only rated @ 86db. I saw where you stated you had the Salons out about 4 ft, which is where I usually place speakers to get a good soundstage depth.

If it were me, with the Salon2 in that room, I would go with mono block amps. As I said in my other post, I'd use Parasound JC1 monos.

 

[Irvrobinson]

I found the source of the problem. The Velodyne DD18 Plus input is overloading, and the high-pass filtered feeds to the ATI amp contains the clipped waveforms that are causing the peak light to activate. Feed the ATI channels full-range at the same volume level and there's no clipping (though the sound is worse).

It looks like a discussion with Velodyne is the next step.

 

[DD66000]

I found the source of the problem. The Velodyne DD18 Plus input is overloading, and the high-pass filtered feeds to the ATI amp contains the clipped waveforms that are causing the peak light to activate. Feed the ATI channels full-range at the same volume level and there's no clipping (though the sound is worse).

It looks like a discussion with Velodyne is the next step.

Let me get this straight; you are sending the signal from the pre-amp to the DD18 and the filtered output to the power amps, onto the mains?
I would never do that. You should always send from the pre to the power amp direct. And if need be, use the pre/pro/AVR to set the XO to the mains.
About the only exception to that would be a speaker system like JBL Performance Series. Where the PT800 mains are designed to mount to and connect through the PS1400 subs, to provide a full range speaker system.

 

[TLS Guy]

Let me get this straight; you are sending the signal from the pre-amp to the DD18 and the filtered output to the power amps, onto the mains?
I would never do that. You should always send from the pre to the power amp direct. And if need be, use the pre/pro/AVR to set the XO to the mains.

I agree, he should use the high and low pass of his pre/pro.

Obviously the front end of the Velodyne does not have enough head room.

I missed this. He said in an earlier post, that he was not using a pre/pro just a preamp. So his only active crossover is in his Velodyne, and obviously it does not have enough head room.

So the question becomes, whether the lack of headroom is at the input of the Velodyne, or the output. If it is on the input, he could build a 6db L- pad and advance the volume on his sub. However if the lack of headroom is after the volume control of the sub, there is not help for him doing things the way he is.

The only thing he could do would be to build a crossover round mini DSP boards. He might be able to adapt an analog active crossover also.

Unfortunately when you are doing a custom job like this, a full set of test gear is really very important. A signal generator and scope are at least called for to engineer his way out of this problem.

His other option is to purchase a pre/pro. Unfortunately headroom is seldom specked and it is one of the most important pieces of data on any voltage amplifying device. Inadequate headroom is a very common problem.

 

[DD66000]

I agree, he should use the high and low pass of his pre/pro.

Obviously the front end of the Velodyne does not have enough head room.

I missed this. He said in an earlier post, that he was not using a pre/pro just a preamp. So his only active crossover is in his Velodyne, and obviously it does not have enough head room.

I also forgot.
The easiest thing the op could do is to do replace the pre-amp with a pre-amp with built-in bass management. One such pre is Parasound P7. It is a 7 channel analogue pre, but no reason one could not use it just for stereo.

 

[TLS Guy]

I also forgot.
The easiest thing the op could do is to do replace the pre-amp with a pre-amp with built-in bass management. One such pre is Parasound P7. It is a 7 channel analogue pre, but no reason one could not use it just for stereo.

I have just re read his original post. His high pass is first order, so all he needs is a cap in series with the input of the amp channels driving the bass section of the salons.

The input impedance of his ATI is 28 kohms.

So a 0.07 mfd cap in series with the input will give him the first order crossover at 80 Hz he needs.

So he just need to make up special connecting leads to those, amps. He needs a Y going to his Velodyne. So one side of the Y connectors goes to his Velo, and the other to the amp channels supplying the bass section of the Salon2 via the special leads containing the 0.07 mfd caps in series, one for each channel, and he is done.

 

[Irvrobinson]

Let me get this straight; you are sending the signal from the pre-amp to the DD18 and the filtered output to the power amps, onto the mains?
I would never do that. You should always send from the pre to the power amp direct. And if need be, use the pre/pro/AVR to set the XO to the mains.
About the only exception to that would be a speaker system like JBL Performance Series. Where the PT800 mains are designed to mount to and connect through the PS1400 subs, to provide a full range speaker system.

I don't use electronics with bass management capabilities.

I use four channels of amplification. The mid-high section of the mains are driven by dedicated amp channels, and those channels are driven direct from the pre-amp. (A Benchmark DAC1 HDR). So the high-pass filter is not in the mid-high section signal path. The high-pass filtered output is only sent to the woofer section of the mains, which have use a passive low-pass crossover at 150Hz, and are powered through another set of amp channels. If there is any signal degradation by using the Velodyne high-pass filter outputs I've never heard it.

 

[Irvrobinson]

So the question becomes, whether the lack of headroom is at the input of the Velodyne, or the output. If it is on the input, he could build a 6db L- pad and advance the volume on his sub. However if the lack of headroom is after the volume control of the sub, there is not help for him doing things the way he is.

The same thought about padding down the voltage and turning up the DD18+ volume had occurred to me, but for what I paid for that sub I want Velodyne to fix it or take it back. I think it's a design flaw.

 

[GranteedEV]

The input impedance of his ATI is 28 kohms.

So a 0.07 mfd cap in series with the input will give him the first order crossover at 80 Hz he needs.

Is this what is referred to as a PLLXO?

 

[DD66000]

I don't use electronics with bass management capabilities.
The high-pass filtered output is only sent to the woofer section of the mains, which have use a passive low-pass crossover at 150Hz, and are powered through another set of amp channels. If there is any signal degradation by using the Velodyne high-pass filter outputs I've never heard it.

But in fact you are using BM. Its just that the DD18 is doing it. And that is the problem. As the Salons have their own XO for the bass. So the signal going to the three 8" drivers are being filtered twice. That is what you don't want.
If you want to bi-amp the Salons, that is fine. But you do not want the signal running through two XOs.

 

[Irvrobinson]

But in fact you are using BM. Its just that the DD18 is doing it. And that is the problem. As the Salons have their own XO for the bass. So the signal going to the three 8" drivers are being filtered twice. That is what you don't want.
If you want to bi-amp the Salons, that is fine. But you do not want the signal running through two XOs.

Of really? Then why does it measure so much better when I use the high-pass filter on the DD18+?

You see, it works like this. The DD18+ is placed for minimum room modes in its operating range. It also includes equalization, and the woofers on the Revels don't have equialization. So the combination of bass-optimized placement and being able to chop down the amplitude of the peaks below 80Hz make the system measure and sound (especially sound) a lot better.

 

[DD66000]

I have heard the Salons run full range w/o a sub and the sound was fantastic.
Can a properly placed sub be better? YES. BUT you are only talking about EQ <80 htz. Above 80, the signal being produced by the 8" drivers, is being filtered twice. I don't see how that produces better sound.

 

[GranteedEV]

Above 80, the signal being produced by the 8" drivers, is being filtered twice. I don't see how that produces better sound.

maybe it produces the same sound above 80hz, and better sound below 80hz.

Holistically, that would be "better sound"