80hz & below to sub, how many watts to mids/highs

[jp_over]

Friends,

Did a search but did not come up with much.

Here's the question. If I have everything below 80hz going to the sub (via the receiver's bass management), how many watts is appropriate to get my mids nice and loud (Salk SongTowers).

Since my SongTowers can handle up to 250 watts RMS (solid state), I was debating on using a Behringer 2496 DCX with a couple of Yamaha P2500 pro amps (also looking at Quad 909s) to squeeze max performance with tons of headroom. I'd use the receiver as a pre amp in this plan.

Of course, I'll be using a sub and, from my days in car audio, I recall that 105 watts RMS (such as the Yamaha RX-A1000 provides, even plus a little more since the Salks are 6 ohms) is plenty loud for mids & highs.

Room is about 2500 sq feet, main goal is music BTW.

Thanks for any input/advice.

 

[JerryLove]

Here's the question. If I have everything below 80hz going to the sub (via the receiver's bass management), how many watts is appropriate to get my mids nice and loud (Salk SongTowers).

Depends on your definition of "loud".

1w = 88db @ 1m
10w = 98db @ 1m
100w = 108db @1m

I believe the sensitivity from salk is anechoic, so you can likely add 4db to all those for the room. Then subtract for distance

Here's a calculator for loss by distance (http://www.sengpielaudio.com/calculator-distance.htm). It's about -6db with each doubling (-6 @ 2m, -12 @ 4m, etc).

Since my SongTowers can handle up to 250 watts RMS (solid state), I was debating on using a Behringer 2496 DCX with a couple of Yamaha P2500 pro amps (also looking at Quad 909s) to squeeze max performance with tons of headroom. I'd use the receiver as a pre amp in this plan.

A DCX won't really give you anything unless you are planning in pulling the passive crossovers.

The P2500S is a good amp (I have one), but remember that it has a manual on-off switch.

Of course, I'll be using a sub and, from my days in car audio, I recall that 105 watts RMS (such as the Yamaha RX-A1000 provides, even plus a little more since the Salks are 6 ohms) is plenty loud for mids & highs.

You can't turn watts into volume without knowing sensitivity and distance (at minimum).

 

[sholling]

A 130w receiver will drive them pretty well, or an Emotiva XPA-3 will drive the heck out of them. The XPA-3 is capable of putting out over 300wpc @ 4ohms.

 

[jp_over]

Thanks for the fast replies!

"A DCX won't really give you anything unless you are planning in pulling the passive crossovers. "

I would really just be using it to crossover the sub so I guess this would be a bit of a waste. The other purpose would be to boost the receiver's output for the P2500s.

Also, I am closely considering the XPA3.

I posted this thread because I was very close to purchasing the Yamaha RX-A3000 simply for the extra watts over the other receivers in that line.

However, all the features (it seems) I need are available on the RX-A1000. I don't run any extra zones and don't plan to. I figured with the price difference I could just buy another amp (such as the XPA3 or the P2500/2496 DCX route).

Jerry, thanks for the link. I'll be adding it to my favorites.

For the P2500s "on/off", I figured I'd just add a delayed power strip (such as the bitz power saver). Of course, now this route does not seem as beneficial.

http://catalog.bitsltd.us/

 

[Swerd]

According to Jim Salk and Dennis Murphy, the STs can be driven by any amp that delivers an honest 50 wpc at 8 ohms. They can handle much higher power, but don't require it. Almost any home theater receiver can drive them.

I've heard STs driven by these different amps or receivers. None of them had any problems at all driving them:

Denon AVR 1800 receiver (70 wpc)
Outlaw Audio RR2150 stereo receiver (100 wpc at 8 ohms, 160 at 4 ohms)
B&K AVR 507 receiver (125 wpc at 8, 185 wpc at 4)

B&K EX4420 2-channel amp (200 wpc at 8, 350 wpc at 4)
Three different AVA 2-channel amps:
Insight 240 (125 wpc at 8 ohms)
Ultra 550 Hybrid amp (250 wpc at 8 ohms)
Ultravalve tube amp (35 wpc at 8 ohms)

I'd try using your receiver first. If you want more power, I suggest looking for something used from Audiogon. I bought my B&K amp there for $400. That's $1 per watt (at 8 ohms) .

 

[GranteedEV]

The sensitivity rating of most speakers is usually averaged for their whole passband from -3db point to -3db point.

The songtowers are 88db sensitive from 42Hz - 20(+)KHz

So in that region 1w would already get you purty loud on average but limit dynamics.

50w would probably have you happy in most rooms.

Beyond that, you're probably going to hit the linear limitations of the 5" drivers. This is where bringing in a subwoofer helps. Those 5" drivers require a lot less excursion at 100hz than they do at 40 hz. The main thing is to not be attempting to reproduce the lowest frequencies with them. this in effect lets you go louders. So if your crossover frequency is 80hz, we have to know if this is a -3db point(Butterworth) or -6db point (Linkwitz-Riley). Normally I don't have a clue but it sounds like you're using a DCX which means you should have a lot more control over this than usual.

The steeper the crossover, the less deep your mains are probably going to be asked to reach, which will give you more linear headroom. This should also help you with some phase issues which can occur in crossing subs to mains although you should still experiment with subwoofer phase to get a seemless blend.

The shallower the crossover, the simpler the circuit. This is pointless with digital finite impulse response filters of course. I don't really see the advantage of digital low order filters to be honest. Only in the analog realm does low order ever "help".

Now I read the other day at another board that when the LFE channel is redirected to the L/R mains, bass dynamics are compressed/limited by most receivers. So if you plan on watching movies you may want to think this over very carefully.

Anyways so we know if we've got a steep crossover we can squeeze more out of the 5" mid range drivers of the Song Tower because they're asked to reproduce less bass which is where their limitations are. Salk states "80 -250 solid state watts" which I read as suggesting essentially "as much power as you feel comfy... you won't use it!". 250w for example might give you a bit more dynamic power but at that point I would be unsurprised if the drivers themself reach THERMAL limits and hit compression. I don't think the song towers are really designed to play LOUD. You'd have to step up to something like a V3 in Salk's lineup for that IMHO. Which btw looks awesome

If I were getting song towers I'd be happy with about 140w into 8 ohm / 220w into 4 ohm type amplifier.

 

[JerryLove]

I would really just be using it to crossover the sub so I guess this would be a bit of a waste. The other purpose would be to boost the receiver's output for the P2500s.

You can just use a $5 plug converter, or a $20 converter with gain (there's a -6db change)

Also, I am closely considering the XPA3.

By all accounts an excellent amp.

I posted this thread because I was very close to purchasing the Yamaha RX-A3000 simply for the extra watts over the other receivers in that line.

However, all the features (it seems) I need are available on the RX-A1000. I don't run any extra zones and don't plan to. I figured with the price difference I could just buy another amp (such as the XPA3 or the P2500/2496 DCX route).

Sounds like a good choice... you still don't need the DCX. You can likely run without gain (I do on one setup), or you can get a converter with gain for far less than a DCX.

OTOH: If you are really adventurous, perhaps you can get a pair of Song Towers with no crossovers and multiple inputs. I'd think it might cut the speaker cost (less parts) and you could get an program the DCX.

If, however, there is epic fail: you have bad sound until you fix it (and you are gonna need gear and software to really try).

If you want the safe version of my advice: buy the AVR with the features you want (and pre-outs). See if you like that. If you want more power, add the Emotiva.

 

[AVRat]

Room is about 2500 sq feet, main goal is music BTW.

Is that sq ft or cu ft?

 

[jp_over]

Is that sq ft or cu ft?

2500 cubic feet.

Thanks for all the replies; I've got quite a bit to think about now!

Jerry,

What receiver (or preamp) are you running that doesn't require gain adjustment for the Yamaha P series?

 

[mtrycrafts]

...Here's a calculator for loss by distance (http://www.sengpielaudio.com/calculator-distance.htm). It's about -6db with each doubling (-6 @ 2m, -12 @ 4m, etc).
...

That number is for outdoors and very large spaces like a concert hall. Residential is about 4dB spl or so on distance doubling.