driving a pair of A9' with a single amp

Johnny816

Hi everyone,

I'm new to the Polk community, and also new to the hi-fi world.
My question has to do with powering my pair of A9's with a single amp.
I have a Marantz Nr1403 receiver that has pre outs. I purchased a Crown xls 1500 pro amp that can put out this power

Dual: into 2 ohms- 775W, into 4 ohms-525W, and into 8 ohms- 300W
Bridged: into 4 ohms- 1,550W, and into 8 ohms- 1,050

I'm wondering if I can run the pair of speakers from the bridged mode of the amp, and if so, how does the wiring go?
Or is the bridged mode just for a single speaker?

Thanks for any help
John

deronb1

Bridged is for one channel and greatly increases distortion. 300 w is plenty for those speakers. 8 ohns and pretty sensitive 90db. Run them in stereo mode withe Crown and see what you think.

Johnny816

Hi, thanks for the reply,

That's how I have them run right now. With movies they are good, missing some high end stuff and vocals (which I know I need to add a center channel for), but music from a cd played on a blu ray, its disappointing. The high and mid are great, but the bass is almost non-existent.
So I wondered if bridging them would make the bass come alive?

scotvl

Something is setup wrong, I'm running my A9s off of my 125w pioneer sc1227 and I've got tons of bass (I cant wait to get an amp though). Your receiver might not be putting out enough voltage to get the full output from the crown amp, it needs 1.4v for full output. You might need a art clean box or similar to boost the pre out voltage.

Johnny816

The Marantz apparently puts out 1.3v on the pre outs. So is that too low?
I guess I may have to look into a clean box or something.
Thanks for the info!

F1nut

You need to check the set up in the AVR.

Thorton

F1nut wrote: »

You need to check the set up in the AVR.

Agree. This is the first place to start. How big is your room? How do you have the speakers placed and your listening position?

Johnny816

F1nut wrote: »

You need to check the set up in the AVR.

I have, believe me. There aren't a lot of options in the setup menu. There is no option for signal out on the pre amp out, I just assume it happens automatically. I'll have to check again to see if there is something I missed.

Johnny816

Thorton wrote: »

F1nut wrote: »

You need to check the set up in the AVR.

Agree. This is the first place to start. How big is your room? How do you have the speakers placed and your listening position?

My room is 11'x20'. The speakers are in the front corners of the room about 20" from either wall, on either side of the tv.
And I sit in the middle of the couch about 10' away from speakers/tv.
I just don't understand why the bass booms during a movie, and doesn't do much of anything durin music played I'm stereo......

Nightfall

Movies have artificially extended lower frequencies. Unless you're listening to techno or rap, most normal music doesn't have movie booming bass.

What are you listening to?

Johnny816

I'm listening to mostly rock and alternative rock. So maybe just expecting too much from this kind of music

deronb1

Jumpers in? Or bi-wired?

Johnny816

Jumpers still in.....I read that bi-wiring doesn't make any difference

F1nut

Since you get bass when playing a movie, but none or very little when playing music there is some setting that you need to adjust.

mikeyb128

300 watts from that crown should run them easily (although not too familiar with pro stuff). I had 200 watts on my A9's from an xpa3 back in the day and they had more than enough bass with music, enough to p1ss off the neighbors.

Nightfall

Can you find a higher quality version of this song?

https://www.youtube.com/watch?v=cqJJwv_Caaw

How does that play? That song vibrates my entire apartment and I'm only running off an AVR. Not sure if the YouTube version is good enough though, see if you can get a FLAC of it or even Spotify would be better than YouTube.

Johnny816

nbrowser wrote: »

I know with myRTiA7s I needed a bit of a bump in the bass knob to get my favoured amount of low end out of them, receiver or dedicated amp but looking at your gear, a mini Marantz is a fine pre/pro when used for that purpose however the amp is a bit of a light weight when it comes to current and that's what the RTi A7/9 needs to shine. Might I suggest looking into a used Parasound or B&K amp for those beastly speakers?

Yeah maybe I'll have to look into a different amp, or get a second crown (one for each tower)

Johnny816

Nightfall wrote: »

Can you find a higher quality version of this song?

https://www.youtube.com/watch?v=cqJJwv_Caaw

How does that play? That song vibrates my entire apartment and I'm only running off an AVR. Not sure if the YouTube version is good enough though, see if you can get a FLAC of it or even Spotify would be better than YouTube.

I'll look that song up when I get home from work and let you know how it goes

gp4jesus

mikeyb128 wrote: »

300 watts from that crown should run them easily...

...& w/500+ available @ 4 ohms, yes their impedance does dip down in some places, that amp should lift them to the moon!

I believe you have a missmatch between your AVR & the Crown. ART makes several Cleanboxes. You want the active one.

http://artproaudio.com/artcessories/audio_solutions/product/cleanbox_pro/

I remember a measly 100W Belles into my 'A7s shaking the foundation during break-in, while listening to selected tracks from George Michael's Faith CD.

Rock on, Tony

Johnny816

gp4jesus wrote: »

mikeyb128 wrote: »

300 watts from that crown should run them easily...

...& w/500+ available @ 4 ohms, yes their impedance does dip down in some places, that amp should lift them to the moon!

I believe you have a missmatch between your AVR & the Crown. ART makes several Cleanboxes. You want the active one.

http://artproaudio.com/artcessories/audio_solutions/product/cleanbox_pro/

I remember a measly 100W Belles into my 'A7s shaking the foundation during break-in, while listening to selected tracks from George Michael's Faith CD.

Rock on, Tony

Thanks Tony!!
I looked into the link, that actually might be te answer. I'm gonna find one and try it

John

Johnny816

Hey guys,
Sad to report that the cleanbox didn't make a difference........back to the drawing board.

rpf65

Just checking. On the set up page, did you go into set up assistant and tell it what you are planing on using. Don't own a Marantz, but whichever brand anybody uses, the AVR has to be told. There is nothing automatic, other than HTIB's, and some sound bars

Johnny816

rpf65 wrote: »

Just checking. On the set up page, did you go into set up assistant and tell it what you are planing on using. Don't own a Marantz, but whichever brand anybody uses, the AVR has to be told. There is nothing automatic, other than HTIB's, and some sound bars

Hey,
I just checked, and there is only set up for input devices, nothing about output to an external amp or cleanbox, seems like that part is automatic.
Thanks for the thought.

John

F1nut

Review the Owner's Manual disc on your computer, then run through your set up doing it via the TV. Write down what you see, then post it here.

Do you use a sub? How is your Blu-ray player connected to the AVR? What does the front panel say when playing a CD? Have you run the calibration program exactly as directed?

tonyb

Johnny816 wrote: »

rpf65 wrote: »

Just checking. On the set up page, did you go into set up assistant and tell it what you are planing on using. Don't own a Marantz, but whichever brand anybody uses, the AVR has to be told. There is nothing automatic, other than HTIB's, and some sound bars

Hey,
I just checked, and there is only set up for input devices, nothing about output to an external amp or cleanbox, seems like that part is automatic.
Thanks for the thought.

John

Inputs is what you want to set up. You have to tell the receiver how to process the signal it receives from each input. There should also be a "system setup".

There is no setup when you add an amp.

Johnny816

F1nut wrote: »

Review the Owner's Manual disc on your computer, then run through your set up doing it via the TV. Write down what you see, then post it here.

Do you use a sub? How is your Blu-ray player connected to the AVR? What does the front panel say when playing a CD? Have you run the calibration program exactly as directed?

Hey F1,
Sorry for the late reply.
I went into the settings this morning and was writing stuff down, and came across a multiEQ page under Audyssey in the audio setup.
When I enabled the multiEQ, then another page was accessible (manual EQ).
so that page looks like this

Channel Front L/R
63HZ 0.0dB
125Hz 0.0dB
250Hz 0.0dB
500Hz 0.0dB
1kHz 0.0dB
2kHz 0.0dB
4kHz 0.0dB
8kHz 0.0dB
16kHz 0.0dB


And to answer the other part of your question, I don't use a sub, the RTiA9 are the only speakers hooked up. I now have rear satellites that I haven't mounted and hooked up yet, and no center channel (still undecided about that). The Bluray is hooked up via HDMI (1.3 I believe).
The front panel says Stereo B-ray when playing a CD

John

Johnny816

tonyb wrote: »

Johnny816 wrote: »

rpf65 wrote: »

Just checking. On the set up page, did you go into set up assistant and tell it what you are planing on using. Don't own a Marantz, but whichever brand anybody uses, the AVR has to be told. There is nothing automatic, other than HTIB's, and some sound bars

Hey,
I just checked, and there is only set up for input devices, nothing about output to an external amp or cleanbox, seems like that part is automatic.
Thanks for the thought.

John

Inputs is what you want to set up. You have to tell the receiver how to process the signal it receives from each input. There should also be a "system setup".

There is no setup when you add an amp.

Hey Tony,

I have the input set to HDMI for the Bluray, and the is the only device hooked to the AVR at the moment.

John

Johnny816

Hey everybody,
Just to let everyone know, I got a new amp (Behringer iNuke NU6000, 1500 watts per channel)......WOW!!!!!!!!!! Now my A9's sound like I knew they could.
Thanks for all the suggestions

John

comfortablycurt

One thing that's worth pointing out -

You are using professional live sound amplifiers for a home stereo. This isn't really an ideal setup. Amps produced by companies like Crown and Behringer aren't exactly designed with home audio in mind. They can certainly attain the volume, but they lack the resolution of higher quality home stereo amplifiers. They're designed to be used in live sound situations that call for extreme volume, with an acceptable sacrifice in sound quality. The volume levels needed for live sound far surpass the volume levels needed for home listening.

It sounds like you've got things figured out, but if you are looking into another new amp sometime down the line, this is a point worth keeping in mind.

Johnny816

comfortablycurt wrote: »

One thing that's worth pointing out -

You are using professional live sound amplifiers for a home stereo. This isn't really an ideal setup. Amps produced by companies like Crown and Behringer aren't exactly designed with home audio in mind. They can certainly attain the volume, but they lack the resolution of higher quality home stereo amplifiers. They're designed to be used in live sound situations that call for extreme volume, with an acceptable sacrifice in sound quality. The volume levels needed for live sound far surpass the volume levels needed for home listening.

It sounds like you've got things figured out, but if you are looking into another new amp sometime down the line, this is a point worth keeping in mind.

Thanks for the info! I was planning on upgrading in the future when the bank account allows lol. I will definitely will keep it in mind....

Thanks,
John

Jim Shearer

Just a thought:

Assuming that the AVR is set for L&R speakers = Large, then you might look at the back of the Crown amp & check its settings. As a sound tech for a theater group, I know that (at least some) pro amps have a bunch of selection (option) switches on the back. One of the amps I use in our studio has a 75 Hz high pass filter option for when you want to limit low freqs--something that would kill your bass! Worth a look?

Cheers, Jim