Is there a real benefit to preamps or two channel amps in HT?

[Rambo4]

This is more of a general question, as it gnaws at me a bit because I don't quite understand the benefit to your system to have these amps hooked up.

From my own experience I have a dedicated room and a 7.1 HK 635 receiver that puts out 75 watts of quality power to all speakers, and the max I can stand volume-wise is around the -15dB mark. I guess what I would like to know is how would it benefit someone to purchase more power, if you already cannot max out your volume without much discomfort.

Again, I have never looked into this type of equipment much, but as I read posts on this forum, I get curious and would like to find out more. And given that I am sure there is a logical reason to purchase an amp, preamp, etc. where would one look to research an entry level amp?

Or save money for a better receiver and be done with it.

[Wayne A. Pflughaupt]

Well, back in the “old days” it was said that your amplifier section was pretty much maxed out with the volume knob at about the halfway mark. I.e., visualizing a level meter that swings up and down with program material, further increases were merely pushing the “down” signal up against the ceiling (otherwise known as clipping).

Not sure how well that translates to modern equipment with digital volume controls, but the theory should be the same. So, if you’re never getting your volume control passed the half-way mark (I’d determine that by min. and max. readings on the digital volume indicator) you’re probably fine.

Keep in mind that if you do get an outboard amp, the conventional wisdom is that you have to double current power or it’s not worthwhile.

Regards,
Wayne

[Rambo4]

Thanks for cutting through some of the jargon, Wayne. I felt I may be missing out. I always had amps in my car stereo days, but turning the stereo past one quarter would render you immobile. I prefer quality to quantity nowadays, so it's good to know amps for home theater aren't a complete necessity.

[tonyvdb]

In order to get "better" sound quality when going with amps and pre amps you need to look at spending allot more. Most receivers in the $600+ range have very good amplification built in. Going with separates once in this range is in my opinion a waist of money. The only advantage with a separate amp is on the mains as this relieves the receiver of some of the load and alows the other 5 channels to get the full power available as some movies these days will use all 7 channels simultaneously at fairly good levels taxing the power supply in the receiver.

[macrae11]

Well I'll chime in. Although I'm a relative noob to home theatre, I do have some experience with speakers and amps.

If we knew what speakers you're using we could also tell if your receiver is putting out adequate power. For example if you're pushing 75w into speakers that are expecting to see 200w of power and you're running at moderate to high levels(which -15dB generally is in a digital receiver) you could be significantly under powering the speakers. For average volume program material you're probably fine, but when that big explosion hits the amp needs to draw more power in order to reproduce the sound. If this transient requires more power than the 75w it's capable of, then it goes into clipping. This sounds bad and is potentially hazardous to your amp and speakers. If you're running into 20w speakers this scenario likely won't be an issue.

However there is the subjective sound quality issue that dedicated amplifiers sound better than IC based amps in all in one receiver amp combos, and that bi-amping can sound better than using an active crossover. However as tony eluded to, it starts to take way more money and you run into the law of diminishing returns.

I'm not really sure what the best bang for the buck would be in the entry level. Some of the more sought after amps come from Bryston, McIntosh, Crown, Krell etc. Any one of these will be multiple thousands of dollars for a surround setup.

[Rambo4]

Thanks for chiming in. The speakers are all Athena Audition Series bookshelf speakers... As-B2's, As-B1's. Center is AS-C1, and surrounds are As-R1.2's.

Average around 91dB sensitivity, and power handling around the 150 watt area. About double of what the Harman is pushing.

[tonyvdb]

With that sensitivity and at 150watts your HK will probably be fine although if running a movie with alot of surround use it will most likely run out of steam well below the 75watt output. HK is good at rating there amps properly so it should be fairly accurate to 75watts.

[macrae11]

Yeah what Tony said. You probably have enough power for those speakers as long as you're running not to hot. However also like Tony said, if you're running a bit louder and particularly if there is a lot of surround information, you would probably be running your amp into clipping at least on louder parts of the program. Not only will this sound bad, but over time could be damaging to both your amp and your speakers.

[PT800]

One thing you didn't mention is the size of your room.
I also have the 635, but I power 5 of the channels with a Parasound 220wpc amp, the speakers are rated for 250w. Only the rear channels are powered by the HK. In a room 3130(sliding doors closed)~6400 cuft. Counting subs, 4100w total.
For most movie channels, I've got the master volume between -20 ~ -15. The speakers are rated @ 91db, and have a quite smooth top end, not edgey.
So even though the HK is conservtively rated, if your room is quite large it would help to use more power.

[Rambo4]

I never thought of it that way... I have a 18 x 14 x 8 ft room. So a little over 2000 cubic ft.

[macrae11]

Well I'll have to disagree with you somewhat here DS-21. If you're running speakers that are significantly more powerful than your amp, you will suffer significant loss of performance. Now you could upgrade your receiver yes, but most modern receivers don't offer enough power to run larger speakers. For example here at work, we have a cheap yamaha receiver then going into QSC power amps to run some 12" 2 way speakers. The yamaha(or almost all modern receivers) doesn't have nearly enough power to run those speakers. particularly when we have to jack it up a little bit to impress clients.

As you said this can also be the case for smaller but less efficient speakers as well. Dynaudios for example are famously inefficient but sound amazing. In order to power many of them to their maximum potential they would require an external amp.

Also when you do run discrete components they often are of higher quality than all in one solutions. Now this will give you marginally better return for a much higher investment, but still an improvement. Your always fighting against the law of diminishing returns, but it is hardly a silly waste of money, at least if you're striving for the highest audio quality.

[Rambo4]

Also when you do run discrete components they often are of higher quality than all in one solutions. Now this will give you marginally better return for a much higher investment, but still an improvement. Your always fighting against the law of diminishing returns, but it is hardly a silly waste of money, at least if you're striving for the highest audio quality

.

I can see your point, I suspect I would really get the "most" out my setup this way. But when the price of an amp is close to that of my receiver and speakers together (@$2000), I am a bit hesitant. If I find one second hand for the right price I will likely go that route, but until then I will stick with what I have. For the sake of my marriage.

Having had amps in my car stereo days, I am a bit concerned with the amount of hiss that would come through as a result of upping the power? I assume nowadays the quality amplifiers for the home have no issue at all with this.

[tonyvdb]

Rambo4 wrote:

.
I am a bit concerned with the amount of hiss that would come through as a result of upping the power? I assume nowadays the quality amplifiers for the home have no issue at all with this.

If you have the input levels and the gain structure right there is usually no issue with this.

[dtb300]

DS-21 wrote:

As for preamps, the main benefit (in addition to the above) is that separates are the traditional audiophile route, so your system will have greater audiophile appeal.

Just a decent pre amp will sound better than most receivers used as pre amps. It is not an "audiophile" thing, it is about better sound. One has to look at what they want to do with their system, 2 Ch or HT? For 2 Ch, using a receiver is a good starting block for those on a limited budget. But for improvement in sound quality separate pre amps and power amps will never be beat by a receiver. Will it cost more, probably, but it is up to each person to decide if the cost is worth it. Nobody can decide that for you.

The main disadvantage is that it's generally cheaper today to buy a new fully-featured, sonically transparent AVR than to buy a new preamp.

No component is sonically transparent - every component has their own signature which they add to the sound throughout the entire chain. And the biggest culprit to corrupt your sound, your room.

Otherwise, adding a separate amp to a receiver a silly waste of money.

Now this I agree with to a point....unless one is upgrading parts of their system at a time. The power amps may come first, then a new processor (HT) or pre amp (2ch).

Remember there are Pre Amps out there with HT passthrough, so one can have a 2CH setup but also be able to integrate HT into it.

But if one is completely into the HT thing, then there is no need for a 2ch pre amp.

[tonyvdb]

dtb300 wrote:

Just a decent pre amp will sound better than most receivers used as pre amps. It is not an "audiophile" thing, it is about better sound. ..... But for improvement in sound quality separate pre amps and power amps will never be beat by a receiver. Will it cost more, probably

This was the case up until about 3 years ago but is no longer. I would challenge anybody to prove that separates "sound" better than a good quality $700 or more HTR. On paper they may look better but in real life use I highly doubt this unless as I have stated before you spend a huge amount more.

The mass production of parts used in building all of the HTR's and pre-pro equipment has lowerd the cost of the high quality DA's and such that this is no longer true. I have a close friend who has a Sunfire Pre Pro along with a Sunfire multi channel amp and neither he or myself can hear any difference between my system or his.

[dtb300]

tonyvdb wrote:

This was the case up untill about 3 years ago but is no longer. I would challenge anybody to prove that separates "sound" better than a good quality $700 or more HTR. On paper they may look better but in real life use I highly doubt this unless as I have stated before you spend a huge amount more.

I have heard many a Pre-Power Amp combo costing almost the same as the Yamaha, Denon, Onkyo HTR stuff and the 2ch sound quality is much better - more like the real thing - but never the equivalent of the real thing. An example was an ARC LS-2 and a Sunfire Amp (2ch) (person spent under $1000 for them) which was against a Yamaha RX-V2500 with a modified Sony CD Player as the source.

But the REAL question here is can one HEAR the differences. If you cannot hear anything, then love your HTR's and move on as it really does not matter what someone else thinks of your setup, it is yours to love or hate.

Yes you can spend SIGNIFICANT amounts of money on separates, but one has to decide if it is worth it or not. And like hearing the difference, the amount you decide to spend is all personal preference.

The mass production of parts used in building all of the HTR's and pre-pro equipment has lowerd the cost of the high quality DA's and such that this is no longer true. I have a close friend who has a Sunfire Pre Pro along with a Sunfire multi channel amp and neither he or myself can hear any difference between my system or his.

Quality DA's? Are you talking about DAC's (Digital-Analog Converters) here? If so, there is SO MUCH more to it than just the DAC's.

For your tests, you have done side by side comparisons with the same speakers, in the same room with the same source, with the same cables, with the same power and have determined their sound is exactly the same??? Just curious on how your did your testing and comparisons other than just your opinions on the sound. And how do you base your opinions on the sound you are hearing? Just what you think it should sound like or do you use a Movie Theater - plain jane, IMAX 180 like in Boston, live music - what venues, un-amplified, amplified, singers, acoustical, electric, piano, etc.

[tonyvdb]

dtb300 wrote:

Just curious on how your did your testing and comparisons other than just your opinions on the sound. And how do you base your opinions on the sound you are hearing?

I'm not trying to start any sort of debate here so lets keep this nice.

Im really referring to the entire signal path not just the DACs etc.
He was so impressed with how good the Onkyo sounded that he sold his equipment and bought an Onkyo 875 and put the money he saved towards a projector. His system sounds just as good as before in his and my opinion.
I fully agree that separates can sound better but at a significant cost over all with little gain in quality as some of already said.
The new receivers like the Onkyo 805 have a Pure Direct mode for two channel listening and this works fantastic for the purists who want little to no processing of the signal.

[PT800]

Even though I currently use a HTR for a pre/pro, I would say there are very few, if any, receivers that have the same quality circuits to the pre outs as a real pre/pro.
As for two channel, a good pair of separates will always be better than a receiver or integrated amp. And I have done that direct comparision, in same room, with same speakers.

[dtb300]

PT800 wrote:

Even though I currently use a HTR for a pre/pro, I would say there are very few, if any, receivers that have the same quality circuits to the pre outs as a real pre/pro.

Could not agree more. Sure one can spend some large dollars on a Pre/Pro, but there are some good Pre/Pro's out there as the same price at the HTR's and they sound better. Even with pass-through, both HTR and Pre/Pro's affect the sound quality you hear - each imparts something on the playback.

Again, "better" needs to be defined. Sometimes better is based on live music - which in itself can sound great and very poor - then, is the live music amplified or not. The second way to define better is what a person perceives as better - which is very objective unless you are very familiar with their tastes and opinions. Then the cost factor needs to be thrown in - how much do you want to pay for the improvements you hear?

My "better" is based on many types of live music from classical, jazz, and rock/pop at many different venues. My system setup and path for sound is based on a small jazz club, sitting about 5 rows from the stage. Probably the best theater setup I have heard is the IMAX Theater in the Science Center in Boston - but HT is not my main concern.

As for two channel, a good pair of separates will always be better than a receiver or integrated amp. And I have done that direct comparision, in same room, with same speakers.

Yep....agree 100% with you.

[avaserfi]

Amp/Receiver audibility as well as the usefulness of more available power has been discussed here as well.

There has been a large amount of credible research conducted by highly regarded sources such as the Journal of Audio Engineering Society. This research has shown that if an amplifier/pre/receiver is properly designed and operating within its design limitations with regard to the speakers being used there will be no audible differences in a controlled double blind situation despite measurable differences due to limitations within human hearing. Typically at home comparisons are done improperly in such a way to introduce bias into the 'study' such that a specific result is more likely to happen. It is important to note that bias can be controlled for with use of proper method, but it cannot be ignored.