Amp question

[tmurnin]

I owned SongTowers for 9 years. I drove them with either a 70 wpc Denon AVR-1800 (bought in 2000), or with an external 200 wpc 2-channel amp, a B&K EX4420 I bought used for $400 ($1/watt), with the Denon AVR as a preamp. I owned that amp before getting the STs, but I listened to them driven both ways, just to see what difference I could notice, if any.

In my opinion, the difference was not major, but it was noticeable, and it was most noticeable in the bass. It wasn't louder or heavier sounding with more power, but it was more potent and cleaner sounding, with less 'strain' or 'effort'. Was that caused by less distortion at equivalent loudness levels? I can't say for certain. But I am confident in saying that going from 70 to 200 watts (both at 8 ohms), roughly triple the power, made a noticeable difference.

Jim Salk and Dennis Murphy both say to drive STs with 100 watts, but admit than any amp or receiver that delivers an honest 50 watts should be enough. That certainly is what I experienced. But I would add that the ST benefits from more power, can easily handle it, but doesn't require it.

I looked up the NAD T758 and was confused about it's rated power. Is it 60 or 110 watts? Two Outlaw 2220 mono amps, rated at 200 W at 8 ohms, $400 each, would be a great solution. So would the Rotel RB-1572 rated at 250 wpc at 8 ohms, but only if it is also rated at 4 ohms. I didn't see that mentioned on Rotel's RB-1572 web page.

Why did I emphasize the words triple the power? I often heard people say doubling amplifier power makes little difference in sound. If you want to make a real difference, increase power by 10-fold, a whole order of magnitude, or 1 log increase. In reality, that isn't often possible or practical. So, I chose a half a log, the square root of 10, or roughly 3-fold.

The Rotel can handle 4 ohms, claims it will support 500wpc at that impedance (not sure I buy that, but ok). http://www.rotel.com/sites/default/files/product/infosheets/RB1572_InfoSheet.pdf

 

[mazersteven]

18x30, reflective surfaces. All not good but how about some photos

 

[lovinthehd]

Thanks for the response(s)! Trying to answer a bunch of questions here:

the T758 is 60w, so the Rotel would increase power quite a bit.

the room is a finished basement area with hard surface floors (vinyl plank laminate) with an area rug between the speakers and the listing position (roughly 10’ away). I have hung some acoustic wall treatments on the wall opposite the speakers (roughly 2’ away) but the rest of the walls are pretty hard surface, so that isn’t ideal but it is what it is.

I’m not interested in giving up on the speakers. These are well reviewed and well thought of speakers by almost everyone who has experienced Salk, so I believe the issue is in my setup. I also have a Hsu subwoofer connected for some of the lower end bass.

EQ - I did run Dirac on the NAD a couple months after I got everything set up. That improved things a bit and perhaps compensated for some of the room issues but still not exactly what I want.

room size - roughly 18 x 30 x 7.5. System is set up on one of the shorter walls.

I will try moving the towers closer to the wall and see if that helps anything

I see an ACD rating of 60w but an individual channel capability of 110w for the T758....fwiw.

 

[VMPS-TIII]

The Rotel can handle 4 ohms, claims it will support 500wpc at that impedance (not sure I buy that, but ok). http://www.rotel.com/sites/default/files/product/infosheets/RB1572_InfoSheet.pdf

If you can get the Rotel at a good price, why not? Just don't expect it to be a major sound difference besides more power. I would try placing the Fronts 4 feet out into the room and see how that sounds. I did this with my BMR's and it really opened them. Every room is different, so what worked for me might be different in your room. You don't have to commit to a long term placement but hearing what it can do is helpful.

 

[Alex2507]

I say get the Rotel and keep the SongTowers about a foot off the wall in an equidistant triangle with the main listening position. I'd toe them in slightly but not so as to be on axis with the MLP. Ditch the sub until you decide if those speakers can sound good to you in that space.

I've got a version of the ST's too ... I think they're outside of my league as they say. I still can't understand what the guy was thinking when he sold them to me.

 

[AcuDefTechGuy]

I’m considering adding an amp to my 2 ch system, currently powering Salk Song Towers with an NAD T758. I’ve never been thrilled with the sound out of this setup - always thought it sounded a bit “thin” if that makes sense. I emailed Jim Salk and he suggested that the NAD may be a bit underpowered for the speakers and suggested adding an amp.

Your AVR can output about 114W x 2Ch into 8 ohms and 164W x 2Ch into 4 ohms.

NAD T758 V3 A/V Receiver Review Test Bench

Test Bench Two channels driven continuously into 8-ohm loads: 0.1% distortion at 100.6 watts 1% distortion at 113.6 watts Five channels driven continuously into 8-ohm loads: 0.1% distortion at 86.0 watts 1% distortion at 95.3 watts Seven channels driven continuously into 8-ohm loads: 0.1%...

www.soundandvision.com

For a short 10’ listening distance and 88dB/2.83V/m speaker sensitivity, that’s plenty of power for most people.

I would say your system sounds thin because your speakers don’t have enough BASS.

So just add a Subwoofer, instead of an amp, which I would say won’t do anything to solve your “thin” sound.

 

[Alex2507]

the T758 is 60w,

114W x 2Ch into 8 ohms and 164W x 2Ch into 4 ohms

500 watts FTW

 

[AcuDefTechGuy]

500 watts FTW

NAD758:

NAD T758 V3 A/V Receiver Review Test Bench

Test Bench Two channels driven continuously into 8-ohm loads: 0.1% distortion at 100.6 watts 1% distortion at 113.6 watts Five channels driven continuously into 8-ohm loads: 0.1% distortion at 86.0 watts 1% distortion at 95.3 watts Seven channels driven continuously into 8-ohm loads: 0.1%...

www.soundandvision.com

 

[AcuDefTechGuy]

Peak SPL Calculator

88dB/2.83v/m, 10FT distance, 2 speakers within 4FT of wall: with 50W of power, you get 101dB Volume. With 100W, that’s 104dB Volume.

I don’t think many of us listen that loud.

 

[VMPS-TIII]

Peak SPL Calculator

I don’t think many of us listen that loud.

Not for long we don't. And those that do start complaining about Tinnitus later.

 

[ryanosaur]

kingnoob much? (Not hatin’ and wish him well!)

 

[ski2xblack]

Ceiling is low, but that's a sizable room. Depending on your listening levels and distances, perhaps more power is warranted. You should try one of those power calculators to get a general idea.

Peak SPL Calculator

88dB/2.83v/m, 10FT distance, 2 speakers within 4FT of wall: with 50W of power, you get 101dB Volume. With 100W, that’s 104dB Volume.

I don’t think many of us listen that loud.

Thanks for posting that link. @tmurnin should mess around with it. One caveat, I think the calculator assumes 8 ohm speakers, so the sensitivity input should be reduced to account for the 4 ohm load, with the power calculations correspondingly higher.

Also, the OP's room has a low ceiling but is otherwise pretty huge. His Salks, good as they are, will probably impose their dynamic range limits, particularly in the power band below 400 Hz. That would account for a "thin" sound. More watts are only good up to the speaker's thermal and mechanical limits, which are the real bottleneck in such a large room.

 

[TLS Guy]

The Rotel can handle 4 ohms, claims it will support 500wpc at that impedance (not sure I buy that, but ok). http://www.rotel.com/sites/default/files/product/infosheets/RB1572_InfoSheet.pdf

I'm going to back Jim Salk. I doubt your receiver drives those Saks speakers properly. Power amps are not equal, but may look it on the test bench, as that is a resistive load. However speaker loads are very seldom resistive and have impedances that vary with frequency and so do the phase angles. Now we are at a point where the four ohm performance is seldom specked any more. The important parameter of source impedance is seldom specked.
My point is that unless an amp has a substantially greater output at 4 ohms compared to 8 and has a higher than average source impedance then that amp will make a lot of speakers sound thin.

I have only heard your speakers once. I head them at Van Alstine Audio. He demonstrated them to me with a tube amp. I really was not impressed with what I heard, and the sound was on the thin side. I suspect the culprit was most likely the amp, as tube amps have a high source impedance, and therefore are notorious for following the speaker impedance curve. A great deal of the problem is that manufacturers of receivers especially, withhold vital specifications.

So far more likely than not I think a decent amp will do the trick for you.

Since I design my own speakers I stick to one amp manufacturer and have done for over 50 years, mainly to eliminate a variable. So I have used Quad amps exclusively.
They are powerful, reliable and have a very low source impedance. But the main reason I keep to them is because it avoids a variable for me. I do know full well that amps do not sound the same, and differences will increase depending on the load presented. Unfortunately it is difficult but not impossible to bench test with a variety of loads. To think that all amps will behave the same when presented with a wide variety of loads, is just not reasonable and it does not happen. However really good designs will tolerate and perform well with a wide variety of loads than poor amps will.

 

[eljr]

I’m considering adding an amp to my 2 ch system, currently powering Salk Song Towers with an NAD T758. I’ve never been thrilled with the sound out of this setup - always thought it sounded a bit “thin” if that makes sense. I emailed Jim Salk and he suggested that the NAD may be a bit underpowered for the speakers and suggested adding an amp.

A local store has an open box special on a Rotel RB 1572 for $500. That’s a class D amp, but I don’t know if that should concern me or not. Couple questions:
1. Do people think adding an amp would help with the overall performance of the system?
2. Thoughts on the Rotel? I’m not looking to spend a ton of money here so open to alternatives but want to keep the budget under $1k for an amp

If you don't like the sound upgrade the speaker. The amp is gonna do nothing.
Seriously.
This is not rocket science. This is basic.

 

[TLS Guy]

If you don't like the sound upgrade the speaker. The amp is gonna do nothing.
Seriously.
This is not rocket science. This is basic.

It is not nearly as basic as you think. The amp speaker interface is actually a very complex problem and NOT in any way basic.

 

[eljr]

I’m not interested in giving up on the speakers. These are well reviewed and well thought of speakers by almost everyone who has experienced Salk, so I believe the issue is in my setup.

I bought an award winning set of low end speakers like these once. Ikon from Dali I believe they were. I upgraded them the next day.
I have been thrilled for years.

Change the speakers, they are not for you.

Peace

 

[eljr]

It is not nearly as basic as you think. The amp speaker interface is actually a very complex problem and NOT in any way basic.

yawn....

 

[Mikado463]

Thanks for the response(s)! Trying to answer a bunch of questions here:

the T758 is 60w, so the Rotel would increase power quite a bit.

the room is a finished basement area with hard surface floors (vinyl plank laminate) with an area rug between the speakers and the listing position (roughly 10’ away). I have hung some acoustic wall treatments on the wall opposite the speakers (roughly 2’ away) but the rest of the walls are pretty hard surface, so that isn’t ideal but it is what it is.

I’m not interested in giving up on the speakers. These are well reviewed and well thought of speakers by almost everyone who has experienced Salk, so I believe the issue is in my setup. I also have a Hsu subwoofer connected for some of the lower end bass.

EQ - I did run Dirac on the NAD a couple months after I got everything set up. That improved things a bit and perhaps compensated for some of the room issues but still not exactly what I want.

room size - roughly 18 x 30 x 7.5. System is set up on one of the shorter walls.

I will try moving the towers closer to the wall and see if that helps anything

with regards to your room, width and length are just fine and while ceiling height could be a little better it's workable.

If it were me I'd start off with some corner bass trapping along with side wall first point of reflection treatment. Possible ceiling treatment might be in order as well along with increasing throw rug size between listening position and speakers. Baby steps ....baby steps

With regards to amp / speaker synergy I'm in agreement with Doc (TLS guy)

 

[Movie2099]

I’m considering adding an amp to my 2 ch system, currently powering Salk Song Towers with an NAD T758. I’ve never been thrilled with the sound out of this setup - always thought it sounded a bit “thin” if that makes sense. I emailed Jim Salk and he suggested that the NAD may be a bit underpowered for the speakers and suggested adding an amp.

A local store has an open box special on a Rotel RB 1572 for $500. That’s a class D amp, but I don’t know if that should concern me or not. Couple questions:
1. Do people think adding an amp would help with the overall performance of the system?
2. Thoughts on the Rotel? I’m not looking to spend a ton of money here so open to alternatives but want to keep the budget under $1k for an amp

If you can add $4,000 more to your budget, you can get the McIntosh MC152 2-channel amp. I think that would be a perfect addition to your setup. You can't say no to the legendary blue watt meters.

 

[AcuDefTechGuy]

If you can add $4,000 more to your budget, you can get the McIntosh MC152 2-channel amp. I think that would be a perfect addition to your setup. You can't say no to the legendary blue watt meters.

I don't know. Might not be enough power to improve that thin sound, regardless of how much power the speakers really need - you know based on speaker sensitivity, distance, and volume.

The MC152 is "only" 150W x 2Ch into 4 ohms. His current NAD AVR can output 164W x 2Ch into 4 ohms.

To increase the volume by another 3 whole dB, he would need to increase to 300W x 2Ch into 4 ohms so that he could get reach 109dB volume.