Need AV Receiver Recommendation for 4 ohm speakers - AVS Forum
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post #1 of 56 Old 06-25-2014, 06:19 PM - Thread Starter
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Need AV Receiver Recommendation for 4 ohm speakers

My old Denon seems to have had it. The problem is I'm running a set of 5.1 M&K THX Select speakers that are 4-ohms.

I was looking at Yamaha's RX-V675, but it looks like you can only run 4-ohms in the front, not 5 channels of it.

Anyone have a sub-$500 AVR recommendation?

Edit: To be specific: LCR-750THX Front, 750THX Center, S-550THX Surround and V-1250 Powered Sub.
I understand them to be fairly efficient, can the Yamaha safely handle it anyway?

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post #2 of 56 Old 06-25-2014, 07:31 PM
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Not sure there are any receivers in that MSRP price range that are rated for 4 ohm operation.

You could shoot for a discounted mid level receiver which has a better chance of handling 4 ohm speakers.

Experts say to make sure the receiver has proper air clearance (ventilation) with 4 ohm speakers. It may make sense to not push it to it's limits either

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post #3 of 56 Old 06-25-2014, 08:17 PM
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Quote:
Originally Posted by MichaelJHuman View Post
Not sure there are any receivers in that MSRP price range that are rated for 4 ohm operation.

You could shoot for a discounted mid level receiver which has a better chance of handling 4 ohm speakers.

Experts say to make sure the receiver has proper air clearance (ventilation) with 4 ohm speakers. It may make sense to not push it to it's limits either
The one below may be one to try. More than your requested price but close. If there is one in your price range to drive your speakers my feeling is this is the one to do it.

http://www.crutchfield.com/p_745T748...V2.html?tp=179
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post #4 of 56 Old 06-25-2014, 09:39 PM - Thread Starter
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I've never heard of NAD, seems like a pretty small company. Also the 748v2 seems to be on sale in places, but isn't listed on NAD's own website. That's pretty sketchy.

Finally, I can't confirm the 4 ohm support for 5 speakers.

My own research turned up that Denon's 2014 line coming out next week MAY support 4 ohms starting with some pretty low models (including the first model with 7.2 above the 5.2 models).

I'm not too bullish on Denon right now, new releases are usually too expensive, I'm not positive about my information, and I really don't want to wait since I'm without a receiver ATM.

I dunno. The Denon AVR 3300 is likely too old to repair but too expensive to replace.

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post #5 of 56 Old 06-25-2014, 11:10 PM
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NAD make superb power amplifiers. They've been around for donkey years. I would personally save up for power amplifiercation whilst you're at .it.

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post #6 of 56 Old 06-26-2014, 04:08 AM
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Adding an Emotiva amp is always an option, but would need a receiver with preouts.
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post #7 of 56 Old 06-26-2014, 07:33 AM
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NAD has been around a long time and is a well known brand. No idea on their quality and customer support these days but they have made many respectable products in the past

I found the 748 on their website, but no v2 model number so not sure what is up with that

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post #8 of 56 Old 06-26-2014, 07:55 AM
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The NAD 748 has good power but no network connection. You have to be crazy to buy a receiver without that feature/connection these days. The amp is rated at 2x80watt or 7x40watt 8ohm in the brochure. Whoopee. And Denon didn't upgrade their amps inside the receiver to support 4 ohm any better. They added an ohm power limiting switch that the 4311/4520 (flagship) model and most other brands including yamaha have had for years.

The Yamaha 775 only has a 400 watt power supply, yet drives a full set of 4ohm speakers to 110db levels without overheating. It has been bench tested at same power as the 748 without a fan. And it has a full set of preamp outs to allow use of any speaker around with external amps if your ears can handle 120db levels. I tried that and too loud for me.

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post #9 of 56 Old 06-26-2014, 08:05 AM
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Quote:
Originally Posted by DoctorM View Post
I've never heard of NAD, seems like a pretty small company. Also the 748v2 seems to be on sale in places, but isn't listed on NAD's own website. That's pretty sketchy.

Finally, I can't confirm the 4 ohm support for 5 speakers.

My own research turned up that Denon's 2014 line coming out next week MAY support 4 ohms starting with some pretty low models (including the first model with 7.2 above the 5.2 models).

I'm not too bullish on Denon right now, new releases are usually too expensive, I'm not positive about my information, and I really don't want to wait since I'm without a receiver ATM.

I dunno. The Denon AVR 3300 is likely too old to repair but too expensive to replace.
This thing about Denon or any other brand being able to drive 4 ohm speakers in anything but their top of the line model is something I find very hard to believe. Brands like NAD do rate their AVR's with that capability. Another option would be to get something with full pre-outs(cheapest at this time) like the Yamaha 775 and the Emotiva UPA 200 for the front two speakers. Another suggestion would be to order the NAD 748v2 from someone like Crutchfield and try it out at home. They have an excellent return policy if you decide it's not doing what you want/need.
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post #10 of 56 Old 06-26-2014, 07:53 PM
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Quote:
Originally Posted by DoctorM View Post
My old Denon seems to have had it. The problem is I'm running a set of 5.1 M&K THX Select speakers that are 4-ohms.

I was looking at Yamaha's RX-V675, but it looks like you can only run 4-ohms in the front, not 5 channels of it.

Anyone have a sub-$500 AVR recommendation?

Edit: To be specific: LCR-750THX Front, 750THX Center, S-550THX Surround and V-1250 Powered Sub.
I understand them to be fairly efficient, can the Yamaha safely handle it anyway?
You may need to spend a bit more for a good-sounding network receiver that can comfortably handle 4 ohm speakers. Our Pioneer SC-1222 receiver powers our big old ADS 710 4 ohm speakers well, and we like the sound.
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post #11 of 56 Old 06-26-2014, 08:58 PM - Thread Starter
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I honestly have zero interest in internet, wireless, or any network service. I just want a good quality AVR that can decode modern audio formats and sounds good driving speakers. Every other device is 'smart' any more, the receiver doesn't have to be.

That said, I poked around Best Buy's Magnolia room today. Besides the guy working there referring to 4 ohms as the 'impotence', he seemed rather knowledgeable. (I had a hard damn time not laughing at him.)

Anyway, I've read articles that say don't worry about 4 ohm ratings, and the BB guy argued that an underpowered amp could cause distortion, an unbalanced load (I think?), and might even damage the speakers (I only thought amp damage was likely). He further said there would be better clarity with a properly powered amp.

Furthermore, he offered to order in some 4 ohm equipment, but found out that the 2014 Denon's showed up just today.
(Linky: http://usa.denon.com/us/product/page...s%28denonna%29)
This year there are models down as low as $450 that handle 4 ohms. I might have had a bad experience with Denon this past time, but a lot of people still seem to dig them and I don't think there are many other receivers in that price range that can do the job.

So... are true 4 ohms necessary? Is Denon any good now a days? Is there a compelling reason to go with any other brand or to upgrade from the Denon AVR-S700W to the AVR-X1100W (which seems pretty close to the same thing with a $50 price difference)?

Also one more odd question. A lot of receivers have only a few analog RCA stereo inputs anymore and I need more than the lower models carry. To upgrade is usually a couple hundred dollars more. Is it worth it or would a basic input switch added on be a good answer for the little used components (cassette deck, record player, etc.) so they can share one line?
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post #12 of 56 Old 06-26-2014, 09:39 PM
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The usual concern for connecting up receivers to 4 ohm loads is that it will run hotter. Receivers should protect themselves for the most part.

A receiver's power supply might perform poorly into a 4 ohm load, which doesn't seem like a risk other than the fact there's no advantage to running a lower impedance.

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post #13 of 56 Old 06-26-2014, 09:56 PM - Thread Starter
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Quote:
Originally Posted by MichaelJHuman View Post
... there's no advantage to running a lower impedance.
Are you saying there is no advantage to running a receiver at a lower impedance when using 4 ohm speakers or are you saying there is no advantage to 4 ohm speakers?
If the latter, I already own them, so I'm just looking for the best way to run them.

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post #14 of 56 Old 06-26-2014, 10:30 PM
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Quote:
Originally Posted by DoctorM View Post
Are you saying there is no advantage to running a receiver at a lower impedance when using 4 ohm speakers or are you saying there is no advantage to 4 ohm speakers?
If the latter, I already own them, so I'm just looking for the best way to run them.
I am saying that receivers/amps that are poor at putting out more power into 4 ohm loads than 8 ohm loads are a bad choice for use with 4 ohm speakers. An advantage to 4 ohm speakers that, assuming similar sensitivity to their 8 ohm counterparts, is more SPL. But only for receivers/amps that can do what they should ideally do - come close to doubling their power into a 4 ohm load.

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post #15 of 56 Old 06-27-2014, 12:42 AM - Thread Starter
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Does this sound as bad to everyone else as it does to me:
Quote:
Originally Posted by Audoholics.com
And remember that Eco mode we mentioned? The folks at Denon smartly tied that in with 4 ohm certification. No, the S700W won’t deliver huge output into low impedance loads. However, the current limiting aspect of the Eco mode (a requirement for the European market) was something that engineers found they could retool slightly to allow folks to safely drive a 4 ohm load without excessive heat buildup. Just realize that once you flip the switch to low impedance mode, you also significantly reduce available output power to your speaker system.
That sounds more like 4 ohm speakers will provide worse performance, but it can handle it.

Edit: I just checked NAD's website. While some reviews say it puts out great power and you can run 4 ohm, the fact is NAD themselves only rate as low as 8... until you step up to the T 777. Thats $3k. A bit outside of budget.

At this point can anyone just name a model of anything that is supposed to handle 4 ohm. My list is short to non-existent right now.

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post #16 of 56 Old 06-27-2014, 02:45 AM
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"At this point can anyone just name a model of anything that is supposed to handle 4 ohm. My list is short to non-existent right now"

hat's why I went seperate power amplifiers. By the time you start spending money on AVR that can drive 4 ohm speakers, you're looking to seperate price class. And then a good budget power amplifier would outclass AVR's.

This would outclass most AVR's, I bet even those at £1500-£2000

http://www.outlawaudio.com/products/7075.html
or
http://www.outlawaudio.com/products/7125.html

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post #17 of 56 Old 06-27-2014, 09:20 AM
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Quote:
Originally Posted by DoctorM View Post
Furthermore, he offered to order in some 4 ohm equipment, but found out that the 2014 Denon's showed up just today. This year there are models down as low as $450 that handle 4 ohms. I might have had a bad experience with Denon this past time, but a lot of people still seem to dig them and I don't think there are many other receivers in that price range that can do the job.
Denon didn't make their amps any more powerful this year. They added an ohm switch. This limits power output so 4ohm speakers don't damage the receiver. Yamaha and some others have had this for years. Try to avoid using it in most cases. Even the flagship denon 4520 has had an ohm switch all along. The NAD specs in their brochures clearly show they don't have extra power in the lower priced models. Preamp outputs on denon start at x4100 but their power supply is beefy so most won't need external amps. I run 4ohm speakers on my weaker yamaha no sweat. Never needed to use ohm switch yet.
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post #18 of 56 Old 06-27-2014, 12:30 PM
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My vote is still for the NAD T748v2. Least expensive at this time for an AVR with full set of pre-outs. Find full test reports on NAD to find out their full power ratings.
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post #19 of 56 Old 06-27-2014, 12:38 PM
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I don't know of anything for $ 500.00. I'm using a Denon 4520 with Martin Logan Motion series 4 ohm speakers. And I have a friend using M & K speakers with a Denon X4000. Not sure if his speakers are 4 ohm, but he hasn't had any problems in a year. Then again, he doesn't run them super loud anyways.

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post #20 of 56 Old 06-27-2014, 12:38 PM - Thread Starter
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As kikkenit2 said, the more I read, the more it looks like official support of 4 ohms is largely a UL certification and if you had it you don't want to actually engage the 4ohm setting. It's a nanny that makes your speakers perform worse.

Buying a good quality AVR is more important. At that point I stayed up till the crack of dawn researching units that officially handle 4 ohm, and units that should be good enough to handle 4 ohm.

The short list ended up having a log of last year's models: Denon x2000 (better bang/buck than getting an s900 or x1100), Yamaha RX-V675 (or v577 (neither has HDMI 2.0)), NAD T 748V2, Onkyo TX-NR727 (the 737 is out of budget and the 727 is still a bit high).

The Onkyo is the only one that officially claims to support 4 ohms.
That said, I think I'm back where I started.

At this point I'm looking for opinions or comments on my nearly solid decision: Yamaha RX-V675. (The v775 seems to have no useful upgrades, not even more power.)
The M&K's are supposed to be pretty efficient for 4 ohms, all low frequencies are sent to the powered sub anyway, I'm only running 5 speakers not 7, and the Yamaha should(?) have decent enough circuitry to handle it all.

Am I crazy, wrong or misguided? (Is Audysey a compelling reason to go Denon?)

Edit: Is there a way to tell if a receiver has enough muscle to run 4 ohms? Some formula with the wattage or something? Even the x4000 is only rated for 6-16 ohms. Same with the NAD.

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post #21 of 56 Old 06-27-2014, 12:59 PM
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Quote:
Originally Posted by DoctorM View Post
As kikkenit2 said, the more I read, the more it looks like official support of 4 ohms is largely a UL certification and if you had it you don't want to actually engage the 4ohm setting. It's a nanny that makes your speakers perform worse.

Buying a good quality AVR is more important. At that point I stayed up till the crack of dawn researching units that officially handle 4 ohm, and units that should be good enough to handle 4 ohm.

The short list ended up having a log of last year's models: Denon x2000 (better bang/buck than getting an s900 or x1100), Yamaha RX-V675 (or v577 (neither has HDMI 2.0)), NAD T 748V2, Onkyo TX-NR727 (the 737 is out of budget and the 727 is still a bit high).

The Onkyo is the only one that officially claims to support 4 ohms.
That said, I think I'm back where I started.

At this point I'm looking for opinions or comments on my nearly solid decision: Yamaha RX-V675. (The v775 seems to have no useful upgrades, not even more power.)
The M&K's are supposed to be pretty efficient for 4 ohms, all low frequencies are sent to the powered sub anyway, I'm only running 5 speakers not 7, and the Yamaha should(?) have decent enough circuitry to handle it all.

Am I crazy, wrong or misguided? (Is Audysey a compelling reason to go Denon?)

Edit: Is there a way to tell if a receiver has enough muscle to run 4 ohms? Some formula with the wattage or something? Even the x4000 is only rated for 6-16 ohms. Same with the NAD.
It's hard to state specifics here. But I will try to list what I think are the key points

- It seems most receivers should handle a 4 ohm load, the unknown is at what volume level does it overheat (or in the worst case shutdown)
- It's not about receiver power as you might think of it; knowing how much power a receiver can put out to 8 ohms does not tell you how much it can put out to 4 ohms; the power it puts out would seem to be depending on the specifics of the power supply, and how the protection circuits in the receiver work
- It's been suggested by a few people before, that mid level receivers can handle 4 ohm speakers as a general rule, but you need to ensure they have proper air space for clearance ( manuals often give some info on recommended clearance)
- If you are running your system at a "reasonable" volume, like -10 dB below reference, the theory says you need little power to hit peaks in movies and way less power for average levels in movies ( less than a watt,) which should be easy for a receiver to handle
- If you are playing music, your average power output is higher, but if you listen at reasonable level ( 90 dB peaks or less for example,) it seems like a pretty safe bet a receiver will handle 4 ohm speakers

- Audyssey seems to be well liked; YPAO seems to be less sophisticated, but I am not sure how much work has been done it recently

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post #22 of 56 Old 06-27-2014, 01:06 PM
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It's not the wattage, although a good amplifier should increase power as impedance drops- the ATI I have outputs 200W into 8ohm, but 300W into 4ohm, it's the control of the speakers. That's full channel, all channels driven, with virtually nil THD. I have a Yamaha 671 and I wouldn't use it for 4 ohm speakers. In fact, the UK version is rated for 4 ohm speakers, the American version isn't.

I'd look into a power amplifier, I've tried 4ohm speakers with that price class AVR and generally not impressed. It drove them, it just sounded bad, really congested.

You don't need to spend a lot of money, something like Emotiva XPA-5 is very affordable, hell power amps over here are double the price. £500 for a 5 channel, 200W per channel? Bargain. I really can't see the problem, you know budget to mid range AVR can't handle 4 ohm speakers, you have 4 ohm speakers which you like. It seems quite obvious what is needed.

A 60W per channel 7 channel power amp will outclass a AVR driving 4 ohm speakers.

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post #23 of 56 Old 06-27-2014, 01:28 PM
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I'd get this one

http://www.outlawaudio.com/products/7125.html

Quote:
Power Output: 7 x 125 watts RMS at 8 ohms, all channels driven from 20 Hz to 20kHz with less than 0.05% THD 7 x 190 watts RMS at 4 ohms, all channels driven from 20 Hz to 20kHz with less than 0.05% THD
AVR's would be in envy of those specs haha. I bet that outclasses Yamaha 3030 and other flagship amps.
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post #24 of 56 Old 06-27-2014, 01:39 PM
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Quote:
Originally Posted by DoctorM View Post
As kikkenit2 said, the more I read, the more it looks like official support of 4 ohms is largely a UL certification and if you had it you don't want to actually engage the 4ohm setting. It's a nanny that makes your speakers perform worse.

Buying a good quality AVR is more important. At that point I stayed up till the crack of dawn researching units that officially handle 4 ohm, and units that should be good enough to handle 4 ohm.

The short list ended up having a log of last year's models: Denon x2000 (better bang/buck than getting an s900 or x1100), Yamaha RX-V675 (or v577 (neither has HDMI 2.0)), NAD T 748V2, Onkyo TX-NR727 (the 737 is out of budget and the 727 is still a bit high).

The Onkyo is the only one that officially claims to support 4 ohms.
That said, I think I'm back where I started.

At this point I'm looking for opinions or comments on my nearly solid decision: Yamaha RX-V675. (The v775 seems to have no useful upgrades, not even more power.)
The M&K's are supposed to be pretty efficient for 4 ohms, all low frequencies are sent to the powered sub anyway, I'm only running 5 speakers not 7, and the Yamaha should(?) have decent enough circuitry to handle it all.

Am I crazy, wrong or misguided? (Is Audysey a compelling reason to go Denon?)

Edit: Is there a way to tell if a receiver has enough muscle to run 4 ohms? Some formula with the wattage or something? Even the x4000 is only rated for 6-16 ohms. Same with the NAD.
The SC line of Pioneer Elites are 4ohm capable and if you look at test bench in Home Theater Mag it will show the D3 amps as having some of the highest output in their price range.
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post #25 of 56 Old 06-27-2014, 01:54 PM
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Quote:
Originally Posted by fatbottom View Post

A 60W per channel 7 channel power amp will outclass a AVR driving 4 ohm speakers.
Say you have a external AVR than can drive your 8 ohm speakers at 60 watts. Let's just say it can do 100 into 4 ohms, at a proper THD, like .1% (and assume all other power ratings I state here are at that or better, 20hz to 20khz)

Now take an AVR that can put out 120 watts into 8 ohms ( typical full bandwidth, two channels driven.) And it's a good AVR that can do 150+ watts into 4 ohms. Let's say the receiver was rated with only two channels driven and the external amp with seven channels driven. We expect the AVR's 150 watt output figure to drop, of course. But under a REAL world load, I don't expect it be worse than 100 watts per channel ( I don't mean driving 4 ohm dummy loads with a test signal, I mean real speakers and real music/movies.)

I can understand an external amp 60 watt amp outperforming a cheaper AVR, but at some point basic electronics tells me it will not keep up with better AVRs that can handle 4 ohm loads, and who can put out a lot of power. I understand the concern that AVRs power specs don't tell the full story, but I have read a lot of bench tests of mid to high level AVRs and they can perform really well ( I have seen some put out well over 200 watts into 4 ohm loads, and I don't think this theoretical 60 watt amp can keep up.)

"But this one goes up to 11"
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post #26 of 56 Old 06-27-2014, 02:10 PM
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yeah at some point. But compare the 125W Outlaw against a $2000 AV amp...

http://www.outlawaudio.com/products/7125.html

190W into 4ohm, all channels, full frequency, with 0.05% THD

Also note THD levels for 8 and 4 ohm loads. The same. And for the AVR? It has to be the same too. Then you have power supply capacity for each channels... what AVR has a 3200VA power supply?

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post #27 of 56 Old 06-27-2014, 02:23 PM
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The outlaw is a great performer. I would say that's all the amp most sane people need at a fair price of 1k. But it's also a 125 watt / channel amp

Heck, if I needed to drive 4 ohm speakers, and did not already have (more than) adequate amp capability, I might look into that one.

But I do feel there's some very capable AVRs out there that can do reference level with no issues whatsoever. And I suspect most people won't listen at reference level, making it pretty easy. I am sure you know it takes under 10 watts to reach 10 dB below reference level with typical sensitivity speakers. That leaves room to push it harder.

Personally, I listen between -17 dB and -10 dB. I think if I were younger, I would push that harder, maybe to -7 dB. But -7 dB needs only 98 dB peaks at listening position ( per channel.) 88 db bookshelf speakers, allowing for a 6 dB drop should not need more than 64 watts peak per speaker.

Like many people on this forum, I did buy external amps, but heard no advantage. Admittedly I have a Yamaha Z7, which is pretty capable, but I remember hearing great sound back in the day with 600 series Yamaha receiver. And my hearing was better then, so presumably I was more sensitive to distortion.

Of course power specs you can trust can be ignored. I have some powered monitors for my synthesizers, and there's no evidence they have near the advertised power. I have overdriven them before and been pretty disappointed ( they likely can't handle the low bass I love to put into my mixes

"But this one goes up to 11"
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post #28 of 56 Old 06-27-2014, 02:32 PM
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Quote:
Originally Posted by MichaelJHuman View Post
The outlaw is a great performer. I would say that's all the amp most sane people need at a fair price of 1k. But it's also a 125 watt / channel amp

Heck, if I needed to drive 4 ohm speakers, and did not already have (more than) adequate amp capability, I might look into that one.

But I do feel there's some very capable AVRs out there that can do reference level with no issues whatsoever. And I suspect most people won't listen at reference level, making it pretty easy. I am sure you know it takes under 10 watts to reach 10 dB below reference level with typical sensitivity speakers. That leaves room to push it harder.

Personally, I listen between -17 dB and -10 dB. I think if I were younger, I would push that harder, maybe to -7 dB. But -7 dB needs only 98 dB peaks at listening position ( per channel.) 88 db bookshelf speakers, allowing for a 6 dB drop should not need more than 64 watts peak per speaker.

Like many people on this forum, I did buy external amps, but heard no advantage. Admittedly I have a Yamaha Z7, which is pretty capable, but I remember hearing great sound back in the day with 600 series Yamaha receiver. And my hearing was better then, so presumably I was more sensitive to distortion.

Of course power specs you can trust can be ignored. I have some powered monitors for my synthesizers, and there's no evidence they have near the advertised power. I have overdriven them before and been pretty disappointed ( they likely can't handle the low bass I love to put into my mixes

My 4520, with a 2 channel Emotiva XPA 200 ( the 4520 only has 9 channels driven ), has no problem driving 11 four ohm speakers cleanly to beyond reference levels in my 388 square foot / 3550 cubic foot home theater. Just FYI.

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post #29 of 56 Old 06-27-2014, 02:33 PM
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Speakers aren't a resistor. Also my brother changed from a 60W to 100W amp (same make) and noticed it sounds cleaner. According to db calc, he should get 102dB. He doesn't listen to it that loud.

I had a 25W amplifier, I didn't think it was great, whatever the reason the 60W provided better sound, even though with dB calc I should get 108dB max with that 25W amp...which is way louder than I ever had it.

I think there is more to it than pure numbers.

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post #30 of 56 Old 06-27-2014, 02:50 PM - Thread Starter
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Um, that spun out of control. Here's where I sit now.
LAST year's Denon x2000 has features I need, it is currently in my budget and is in their InCommand series.

And this: http://denon.custhelp.com/app/answer...-or-power-amps

Apparently Denon always considered their tuners 4 ohm capable, they just never got the UL listing to say so.
It may lose a couple new features from 2014, but it should be a step up from the Yamaha 675 or Denon's more affordable 2014 models.

Edit: Took a quick drive to Best Buy and had them price match Crutchfield. $399 (msrp $700) for the x2000. Will wire that in tonight and see how it sounds.

--
(this space for rent)

Last edited by DoctorM; 06-27-2014 at 04:42 PM.
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