Nad C162 / C272

nnguyen29

I have the following questions for NAD C162 / C272 owners:

1) What is the best way to connect 2 C272s to the C162?
2) I want to use the 2 C272s to drive my 2 RTi150s. Is it better to set the 2 C272s in bridged mode (300 watts @ 8 ohms per RTi150) or bi-amping them (1 C272 drives the highs of the RTi150s and the other C272 drives the lows of the RTi150s)?

Thank you very much!

marker

Try it both ways, in bridged mode and vertically bi-amped and see if maybe you like one better than the other.

The only problems in bridged mode is that distortion is increased slightly, and lower impedance handling is compromised as well.

For a while I ran my RTi12 bi-amped with bridged NAD C270 amps in effect as 300 watt monoblocks driving the woofers on each speaker, with a third C270 in stereo handling the tweets and mids.

nnguyen29

Marker,

Thank you very much for your input!

1) Did you try both way (bridged vs. vertical bi-amped) with your RTi12s? If so, which way sounded better to you?
2) I actually do not have a second C272 yet. I bought 1 about 1 week ago and liked it so much that I thought that with a second C272, the RTi150s would "sing" even better...do you agree with my assessment?

marker

No, I never did try both methods against each other, since in effect I was actually already doing both at the same time anyway.

In either case, the RT150i will sound MUCH better with 2 amps than 1 as it is a power hungry beast that will only benefit from more of it (I take you are running them "large" or full range?).

I had a pair briefly, VERY briefly, but returned them to the store cause at the time all I really had to drive them was a Denon 3803, and they would shut it down!

Since the RT150i has 1 mid driver as opposed to 2 like the RTi12 does, I say just bridge the amps when you get another one.

That way, in effect, you will have a pair of 300 watt monoblocks and let the speaker itself decide where to use the power instead of having maybe more than you really need going to the tweets and mids while maybe not enough to the woofers as might be the case if vertically bi-amped.

I prolly would engage NAD's soft clipping circuitry on them though just to be on the safe side since the RT150i can dip to like 3 Ohm loads.

shack

marker wrote:

I prolly would engage NAD's soft clipping circuitry on them though just to be on the safe side since the RT150i can dip to like 3 Ohm loads.

Problem is that NAD is VERY specific about not trying to drive any load below 8ohm when the 270/272 is bridged. I personally would not take the risk by bridging but would go the bi-amp route.

Polkitup2

I had the NAD C370/C270 amps with the RTi150s, I ran them every which way, bridged, vertical, hortizontal. No problem running them bridged, big club like sound but less quality sound than vertical or horizontal. I finally settled on vertical bi-amp. Just sold the RTi150s and replaced them with NHT speakers. Miss the big Polk sound but like that NHT detail.

nnguyen29

Sorry for asking a stupid question, but what is horizontal bi-amping?

Thanks!

organ

I own the earlier version (C160/270 combo). There are two pre outs on the pre. Use one set for each amp if you want to bi-amp.

However, I'd rather spend more money on a better amp than use two amps for bi-amping or bridging.

Polkitup2

Vertical bi-amp means one of two identical amps powers the left speaker's high and low section and the other amp powers the right speakers high and low section (one channel to the tweets and one to the bass).

Horizontal means one amp powers both the left and right speakers's tweets and another (possibly different) amp powers the left and right speakers bass.

marker

Polkitup2 wrote:

I had the NAD C370/C270 amps with the RTi150s, I ran them every which way, bridged, vertical, hortizontal. No problem running them bridged, big club like sound but less quality sound than vertical or horizontal. I finally settled on vertical bi-amp. Just sold the RTi150s and replaced them with NHT speakers. Miss the big Polk sound but like that NHT detail.

Which NHTs you got?

Polkitup2

Classic 3's up front, absolute zeros in back, and the Classic 3C center.

marker

Good choice. IMO, the Three is a definite upgrade over the SB-3 it replaced, and the SB-3 was certainly no slouch itself. Hell, the new Classic series which replaced the Super Audios are as good or better than the Evolutions! Except for the subs of course. Evolution subs are still MUCH, much better than Classic Series or SA series subs.

What sub or subs are you running?

What amp or receiver, NAD?

marker

organ wrote:

However, I'd rather spend more money on a better amp than use two amps for bi-amping or bridging.

But those RT150i need a LOT of power, and for what another C270 will cost, he won't be able to do any better anyway.

Polkitup2

I use an Outlaw 1070 to power the surrounds and use the pre outs for the fronts and center. I use the NAD C370 to power the fronts, and a NAD C270 for the center.

And I agree with Organ, I wouldn't buy two amps just to bridge or bi-amp. I started with one and eventaully ended up with two.

nnguyen29

Polkitup2

Currently, I am using my HK-525 to power the center and surrounds and pre outs for the fronts (using the C272).

Like you I started out with one C272 and now I am looking to add a second one to bi-amp so my RTi150s can "sing" even better!

My plan was to purchase a new C272 this weekend...until a guy I know wants to sell a C370 to me for $200 less than a new C272.

Should I go for this and use the C370 to power the highs and the C272 to power the lows? Do you happen to know the gain for the C370 and C272?

Thanks!

organ

marker wrote:

But those RT150i need a LOT of power, and for what another C270 will cost, he won't be able to do any better anyway.

It's not really a lot of power they need, but good reserves. Remember, doubling the power will only increase the spl by 3db.

If he holds a little longer and save up some more cash, the selection will be plenty if he doesn't mind going used.

Forgot to mention this before, but I wouldn't bridge the 150's IMO. In bridge mode, the impedance is cut down by half. So if the 150 does indeed dip down to 3 Ohms like you mentioned, the amp will see 1.5 Ohms. You're better off running a single C270 than using two of them bridged.

organ

nnguyen29 wrote:

Do you happen to know the gain for the C370 and C272?

Thanks!

The amp sections should have the same gain because according to NAD, the C370 uses the exact amp section as the 270. But you might want to send NAD an email to confirm this.

nnguyen29

Organ,

I am planning to do vertical bi-amping the RTi150s since this was what most responses recommended.

Also, I was asking the gain for a C370 and C272 (if I was going to purchase the C370 instead of a second C272). The C370 is 120 watts x 2 and the C272 is 150 watts x2 (at 8 ohms)

Thanks!

organ

nnguyen29 wrote:

Organ,

I am planning to do vertical bi-amping the RTi150s since this was what most responses recommended.

Also, I was asking the gain for a C370 and C272 (if I was going to purchase the C370 instead of a second C272). The C370 is 120 watts x 2 and the C272 is 150 watts x2 (at 8 ohms)

Thanks!

Oops, misread your post. Vertical bi-amping makes more sense to me than horizontal.

ok, another thing I forgot to ask. Do the top binding posts connect to the tweeters only or the tweets and mid-range driver? If the lower posts connect to the subs only, than horizontal bi-amping would be the way to go.

nnguyen29

Organ,

I don't really know the answer to your question. Below is information from the RTi150's manual:

CROSSOVER FREQUENCIES:
200Hz, 2.4kHz
CROSSOVER SLOPE:
Woofers LP 2nd Order
Mid/woofer HP 1st Order, LP 2nd Order
Tweeter HP 2nd Order

Can you tell from the above info? If so, horizontal or vertical bi-amping?

Thanks!

organ

All I can tell from the info is that the tweets play from 2.4k and up, mid woofer plays 200 to 2.4k and the subs play from 200 down.

You can check this yourself by connecting your amp to the lower binding posts (no jumpers) and see which drivers become active.

marker

organ wrote:

It's not really a lot of power they need, but good reserves. Remember, doubling the power will only increase the spl by 3db.

If he holds a little longer and save up some more cash, the selection will be plenty if he doesn't mind going used.

Forgot to mention this before, but I wouldn't bridge the 150's IMO. In bridge mode, the impedance is cut down by half. So if the 150 does indeed dip down to 3 Ohms like you mentioned, the amp will see 1.5 Ohms. You're better off running a single C270 than using two of them bridged.

I've had the 150 before, as well as the current RTi12, and trust me on this, they NEED power much more so than a more "refined" amp as they are what they are.

I still say that for what another C270 would cost, he won't do much better with anything else anyway, new or used.

marker

Polkitup2 wrote:

I use an Outlaw 1070 to power the surrounds and use the pre outs for the fronts and center. I use the NAD C370 to power the fronts, and a NAD C270 for the center.

And I agree with Organ, I wouldn't buy two amps just to bridge or bi-amp. I started with one and eventaully ended up with two.

What sub?

Polkitup2

SVS Plus/2 with the new drivers.

univera

I have a pair of Zero's I have used for rear surrounds and they really were awesome. They played much larger than their size indicated. I can't seem to part with them. Then again, I haven't parted with any stuff I ever bought except my JVC rack system back in the day. Thank god it had an unfixable problem. I might not have ever discovered higher end (Rotel at the time) audio and might have "upgraded" to a Bose POS system.