Enough power for low volume?

gatucar

Hello,
I am new here. I have a pair of RTI a 9. I run a very small receiver (Denon stereo with a modest 80 watt per channel). I also have a powered sub connected to the system.
I have read in several threads that a lot of power is needed for these speakers to sound well. Here is where I get lost. Do I still need a lot of power for listening music at low volumes? Most of the time I set my receiver at -35 db. If I get too inspired I may go for -25 db. I fully understand the reason to have lots of power to hear loud music but I cannot understand the benefits of having lots of power when not playing music too loud.
My main question is: Are there benefits expected from running large amps in terms of sound quality when listening music at low volume?
Any comments will be appreciated.
Thanks a lot!

nhhiep

it's not Watt, but current.
I've the same huge speakers as yours. Even thought they sound fine at low vol. But to get any bass out of them, you need to give them both Watts and current. That is where adding an bigger external amp helps.

Joe08867

The benefit of separate amps is the ability to play solidly at all volumes. You will get more definition, better tighter low end, crisper highs, and better overall sound using a separate amp instead of the amplifier built into the Denon.

gatucar

Thank you guys.
It is interesting that even at low vol there is an impact on sound quality. In order to get a good match then I will need to understand how current relates to watts. I have seen guys focusing in fine quality amps of little power and guys trying to put lots of watts in their systems. Is there a sweet spot in between?
Cheers!

DarkHorror

Not at all, and considering you are using a powered sub that removes a lot of the work that the receiver would do. Listening at low volumes you are going to be using far less than 1 watt. Let alone enough to need an external amplifier.

You aren't going to gain anything by getting an external amp and listening at low volumes with a powered sub.

pitdogg2

DarkHorror wrote: »

Not at all, and considering you are using a powered sub that removes a lot of the work that the receiver would do. Listening at low volumes you are going to be using far less than 1 watt. Let alone enough to need an external amplifier.

You aren't going to gain anything by getting an external amp and listening at low volumes with a powered sub.

you're so wrong....

Lietuvis91

gatucar wrote: »

Thank you guys.
It is interesting that even at low vol there is an impact on sound quality. In order to get a good match then I will need to understand how current relates to watts. I have seen guys focusing in fine quality amps of little power and guys trying to put lots of watts in their systems. Is there a sweet spot in between?
Cheers!

Idealy you would give the speaker the power at which it is rated. That is where you are getting 100% capability out of the speaker. Your RTIA9 is rated at 500w. That does not mean you need the max, but the closer you get, the better it should sound.

My M70s sounded wimpy and anemic with just an avr with 110w/ch
125w/ch amp made a big improvement
205w/ch amp made them sound even better. Now they sounded like l thought they should have in the first place for a big speaker that it is, delivering big sound with authority.

The m70 is rated at 275w and those who have tried 250w/ch amps on them say there was even more improvement. But for now, I think i'm close enough because I'm very happy with how they sound.

With your big speaker, I would get an amp that was at least 200w/ch.

danger boy

at low volumes your receiver will do fine.. to kick it up a notch and probably hear more detail from your music.. then you would want to get an external amp(s).

Lietuvis91

DarkHorror wrote: »

You aren't going to gain anything by getting an external amp and listening at low volumes with a powered sub.

You want to power the speaker properly not only for volume but for proper control of the driver. When an amp is underpowered it cannot control the drivers properly and this impacts sound quality, at any volume level. The goal isn't quantity of sound, but quality at a given volume level.

If all you want is quantity and don't care about quality, then you're fine with an AVR, no doubt!
Except, too often, those same people come back later and wonder why that speaker sounds so crappy compared to their cousin's pioneer bookshelfs... :rolleyes:

DarkHorror

Lietuvis91 wrote: »

Idealy you would give the speaker the power at which it is rated. That is where you are getting 100% capability out of the speaker. Your RTIA9 is rated at 500w. That does not mean you need the max, but the closer you get, the better it should sound.

My M70s sounded wimpy and anemic with just an avr with 110w/ch
125w/ch amp made a big improvement
205w/ch amp made them sound even better. Now they sounded like l thought they should have in the first place for a big speaker that it is, delivering big sound with authority.

The m70 is rated at 275w and those who have tried 250w/ch amps on them say there was even more improvement. But for now, I think i'm close enough because I'm very happy with how they sound.

With your big speaker, I would get an amp that was at least 200w/ch.

This is not correct, the 500w is just the max rating on the speaker aka you can put that much clean power to it for a long time and it should be just fine. Heck you could put a 100k watt amp to the speaker and as long as you didn't overpower it it would be fine.

When powering full range speakers at normal listening levels you most likely won't be using more than a couple watts. The big problem for receivers is the bass from full range speakers which can end up straining the amp. With a sub you shouldn't have any need for an external amp. It's also the impedance swings to where the receiver may struggle. But with low listening levels and a sub you have no need for an amp.

Lietuvis91

LOL! ok...

If you can provide some examples of some testing you did that proves your point then... you win.

Otherwise, I'm going to stick to the things I have learned through my own experience

Drenis

keep enjoying that mediocre sound you'll get then.

chumlie

DarkHorror wrote: »

Not at all, and considering you are using a powered sub that removes a lot of the work that the receiver would do. Listening at low volumes you are going to be using far less than 1 watt. Let alone enough to need an external amplifier.

You aren't going to gain anything by getting an external amp and listening at low volumes with a powered sub.

Now thats just silly talk. Add an amp, you will be much happier.

DarkHorror

Which model receiver do you have? Considering it's a stereo receiver it may have plenty of power for what you are doing. Does your receiver have pre-amp outputs? What do you have the crossover set at?

It's not that people don't need amps, they do especially when using hard to drive full range towers. It all has to do with situation, You take an average budget to mid range receiver and try to power some hard to drive towers you will run into problems mostly lack of bass and low to mid-range. The problem is your explanation of why and how things work.

Joe08867

DarkHorror, you really need to hear the difference an external amp makes and then tell me a receiver is good enough.

I am not gonna go and fight over some stupid study when all I need are the ears on my head to tell me what sounds better.

If you want to debate this have fun, but I know from real life experience that separates are always better sounding than an AVR.

DarkHorror

I have heard a bunch of external amps, and depending on the situation sometimes they make a huge difference other times none at all. To figure out if one will make a difference or if the difference will be worth it you need to know what the setup is and how it's going to be used.

You go with full range speakers on a receiver and those speakers may end up sounding like small speakers with no bass, to having a good amp where not it sounds like you have a sub with a good full sound. You can also go will speakers that on a receiver sound the same as they sound with a high quality external amp. It all depends on the setup what you are using how it's setup and what you are coming from.

nwohlford

If your receiver allows you to set a high pass for the main speakers, you should be fine especially at low volumes. The RTi A9 does have low impedance dips and extreme phase angles at low frequencies (http://www.hometheater.com/content/polk-rti-a9-speaker-system-ht-labs-measures), but if you can set the high pass at 80 Hz or higher, these speakers should not be that hard to drive. (I have not seen an impedance or phase angle by frequency graph for these speakers, so there could still be some issues above 80 Hz.)

Whether you should bother with the RTi A9s if you have to crossover at 80 Hz is another issue altogether.

nhhiep

why would anyone bother to cross this speaker? it digs as low and clean as many subs out there

Drenis

DarkHorror wrote:

I have heard a bunch of external amps, and depending on the situation sometimes they make a huge difference other times none at all. To figure out if one will make a difference or if the difference will be worth it you need to know what the setup is and how it's going to be used.

External amps ALWAYS make a difference. Period. You're going to have to spend some coin to achieve what an external amp can bring if you're going to run some sort of integrated (e.g. - Music Fidelity Tri-Vista), never mind an AVR.

Also, Polk openly recommends a source of 200wpc for A9's. It's a statement from Polk CS that's actually been posted in the forums.

DarkHorror wrote:

You go with full range speakers on a receiver and those speakers may end up sounding like small speakers with no bass, to having a good amp where not it sounds like you have a sub with a good full sound. You can also go will speakers that on a receiver sound the same as they sound with a high quality external amp. It all depends on the setup what you are using how it's setup and what you are coming from.

Your last statement is like comparing Klipsch RF towers to Monitor 70's. Do you know what speaker efficiency is? Plus a lot of AVR's have their own "sound".

nwohlford wrote: »

If your receiver allows you to set a high pass for the main speakers, you should be fine especially at low volumes. The RTi A9 does have low impedance dips and extreme phase angles at low frequencies (http://www.hometheater.com/content/polk-rti-a9-speaker-system-ht-labs-measures), but if you can set the high pass at 80 Hz or higher, these speakers should not be that hard to drive. (I have not seen an impedance or phase angle by frequency graph for these speakers, so there could still be some issues above 80 Hz.)

Whether you should bother with the RTi A9s if you have to crossover at 80 Hz is another issue altogether.

A9's will dip to just above 4 ohms at around 60-65 hz I believe. They are solid down to 50hz. That's where one should start crossing over if at all needed.

nwohlford

nhhiep wrote: »

why would anyone bother to cross this speaker? it digs as low and clean as many subs out there

Because that is the only way to run them safely with his receiver. I agree that it is ideal to run them full range with an adequate amp.

Lietuvis91

DarkHorror wrote: »

Which model receiver do you have? Considering it's a stereo receiver it may have plenty of power for what you are doing. Does your receiver have pre-amp outputs? What do you have the crossover set at?

Probably questions you should have asked before telling everyone that an amp will make no difference.

Either way, even if his crossover to an external sub is set to 80hz or even as high as 100hz, he is still using the subs on the a9s because the internal crossover to the subs is @ 120hz. Something tells me you probably didn't know that...

So... you are still trying to push three 7in woofers... in addition to two 5.25 mids and a tweeter. Still think an amp isn't going to help?

C'mon... we've been there and done that. We're not making this stuff up as we go for the sake of arguing... unlike someone here :rolleyes:

nwohlford

Drenis wrote: »

A9's will dip to just above 4 ohms at around 60-65 hz I believe. They are solid down to 50hz. That's where one should start crossing over if at all needed.

Crossing them over at 80 Hz is to avoid the impedance dips and phase angle issues to reduce the load on his receiver. It has nothing to do with the lower limits of the speaker.

BlueFox

What is low volume? 50db, 60db, 70db SPL? I would say if you are going over 60db then a better amp will give better sound at the "low" volume. A lot depends on how efficient is the speaker. Generally, 'better' is always preferable to 'good' or 'okay'. Besides, there will be times when you are not playing at low volume.

Drenis

nwohlford wrote: »

Crossing them over at 80 Hz is to avoid the impedance dips and phase angle issues to reduce the load on his receiver. It has nothing to do with the lower limits of the speaker.

My post was more so FYI.

gatucar

Guys thanks a lot, I apologize for not giving enough details from the beginning.
The receiver model is DRA 397 (it has a pre out). I am running a polk sup with 300 watts. This is the set up: The receiver sends the signal to the sub through the speaker out in the receiver (I am not using the ?sub pre out? from the receiver). Then I have the speakers connected to the sub's "speaker out". I am doing this since the dealer said it was the best way.
Thanks to all.

Drenis

Does that sub have a high-pass filter built into the "speaker out" terminals? What's the sub crossed over at? Do you know what model the polk sub your using is?

gatucar

Drenis,
The model is DSW pro 440 wi. It has a low pass knob which I set arround 80 (more or less, there is a 60 and a 110 mark only).
Thanks

nwohlford

Since your receiver does not have a high pass for the main speakers, I would suggest not using the sub and buying an amp to use.

cfrizz

It's not about having the power to be able to play it loud, it's about the power being able to operate the speakers to their full potential no matter where the volume knob is.

This was the biggest improvement when I added a Parasound 1500A 205wpc amp to my system. Even at low volumes I heard all of the details in my music. I started hearing details out of music that I THOUGHT I knew very well, that I had never heard before when just my receiver was pushing my speakers.

That is why we recommend separate amplifiers.

gatucar

Thanks a lot to everyone. This forum is a great place to learn!
At the end it seems that most of you would get a dedicated amp for my speakers. I will do it in the near future. I will wait a little bit until "the wife" forgets about the towers.:cheesygrin:

cfrizz

Unfortunately, your receiver does not have preouts to add a separate amp, so you would have to upgrade that first.