Amplification For 4-8 Ohm Bp10b's

[caminperth]

Hi all..

I've been reading over some of the recent topics and thought I'd start my own rather than try to take their's over.

I've recently aquired some Definitive Technology BP10B's, corresponding center and bipolar rears and a HK AVR7000 amplifier. It came as a package for $2,500 so I'm hoping it's a fairly ok deal for second hand gear.

My main issue is with the HK amp. While it seems to have plenty of grunt (it's about 28kgs!), it lacks refinement in the midrange area at decent 2ch listening levels. The speakers are rated at 4-8 ohms by the manufacturer's plate, so I'm wondering if the varied impedance could be affecting the midrange sound at higher power levels - ie: overloading the HK.

Is anyone able to comment on if I'll benifit from either adding a power amp or selling the HK and going to separates. There seems to be a few packages of Rotel RMB1075's and RSP1066's floating around ebay and other forums at the moment. Has anyone changed from a higher end intergrated avr to separates of about the same power rating and been massively impressed or is it going to be the case of $ for little gain.

All advice welcome. :)

Cheers,
Cam

[WINEDS]

Cam,
I think you will reap huge benefits by going seperates. Most AVRs don't do 2 channel very well. I recommend you try out some integrateds with HT bypass - eg: MF A3.5, Arcam A90 (I think) etc. Maybe a friendly store in Perth might let you try one at home for a few days?

Cheers,

Paul

[caminperth]

Thanks for the reply Paul. When you say HT bypass, do you mean a direct analogue stereo mode? The HK does that, but I'm not sure if it's a complete bypass of tone controls ect.

I haven't heard of MF or Arcam. I'll do some research, though would really love to go seperates if it's worthwhile and the budget allows.

I think if I could get around 1k for the HK, then I could look at seperates second hand around the 2k mark. Not sure if this would be enough though as even a RMB1075 is only 125 RMS compared to the 110 RMS of the HK in stereo mode. Would there be an appreciable difference aside from the coolness of having a power amp? :biggrin:

Cheers,
Cam

[WINEDS]

Cam,
Integrateds like the MF and Arcam that I menitoned have a feature called HT bypass. It is basically an input that is routed directly to the AMP section of the integrated when you flick to HT mode. So you could keep your HK AVR and just route the AVR FL and FR pre outs to the HT inputs on the integrated. When you are using 2 channel you get the benefit of a dedicated 2 channel integrated, and in HT mode the integrated will drive your fronts (thus taking a lot of strin off your AVR).

The pre section of most AVRs is also a weak link so an integrated could be a good option for you.

Cheers,

Paul

[alebonau]

Cam,
Integrateds like the MF and Arcam that I menitoned have a feature called HT bypass. It is basically an input that is routed directly to the AMP section of the integrated when you flick to HT mode. So you could keep your HK AVR and just route the AVR FL and FR pre outs to the HT inputs on the integrated. When you are using 2 channel you get the benefit of a dedicated 2 channel integrated, and in HT mode the integrated will drive your fronts (thus taking a lot of strin off your AVR).

The pre section of most AVRs is also a weak link so an integrated could be a good option for you.

Cheers,

Paul
[/b]

something like the mf a3.5 as suggested by wineds is very good idea. the integrated takes the load of the avr from driving the mains. has abetter 2 ch pre stage for better 2ch and has similar clean neutral sound matching well with the hk for ht.

[caminperth]

Thanks again for the feedback guys. I am missing something with the connection of the equipment though..

To use one of the intergrateds you're talking about that have the HT bypass mode would it be connected as such?
1. CD to HT amp
2. FL & FR from HT amp pre-out to Integrated input
3. FL & FR speakers to intergrated speaker terminals

If this is the way it works, aren't I still using the preamp in the HT amp and therefore adding another pre-amp to the chain? Wouldn't it be the same to use a power amp instead of an integrated?

Cheers,
Cam

[joz]

In this case the CD would actually be connected direct to your inergrated,as with say a turntable if you had one.This way the intergrated does all the pre work on the critical 2 channel bits.Your dvd source would be connected to the HT receiver, this then would be connected to the intergrated pre.It would be for your dvd sources that the HT by-pass would be brought into play.Though only your front mains go through the by-pass.

Clear as mud ??
I hope that explenation helps!

[caminperth]

Ahh - Thanks, it does..

So I'd basically be running the intergrated separately for most sources and then using it in HT bypass mode with the pre-outs from the HK amp when using surroud.

Hmm - possibly a cost effective solution, but sounds quite complicated to operate for the WAF.

Getting back to part of my original post, does anyone have experience with the definitive speakers and their varied impeedance rating? Could it just be the speakers that are a bit strong in the midrange?

[caminperth]

I'm investigating IRD noRh Le Amp 100 w Mono Blocks for the fronts and was thinking I could run them using the HK as a pre. Possibly not the best arrangement, but better than the HK internal amps?

Thoughts?

[alebonau]

I'm investigating IRD noRh Le Amp 100 w Mono Blocks for the fronts and was thinking I could run them using the HK as a pre. Possibly not the best arrangement, but better than the HK internal amps?

Thoughts?
[/b]

never heard of these mono blocs in question. Keep in mind one of the main improvements with goign with a dedicated 2ch integrated is not only a power amp upgrade but the improvements on the 2ch pre side of it over an avr. Using a 2ch integrated I'm not sure what you mean not good enough for waf ? its pretty simple you jsut selct HT on it for HT and CD on it for CD thats all.

[WINEDS]

Or use a Logitech Harmony universal remote to control everything. Even the dog can use it! Press * "watch my TV" (buttons) to see the PAL commercials OR * "Listen to MY Music" (buttons) for "how much is that doggy in the window" :D

[caminperth]

WINEDS hit the nail on the head. waf = wife acceptance factor..

Thanks for the input. :)

[Drizt]

I can definately say that the MF a3.5 (thanks wineds) made a HUGE difference in increasing quality of 2ch over what my Denon AVR could do. Well worth the investment.

and its a piece of piss to operate.

[Rick]

Getting back to part of my original post, does anyone have experience with the definitive speakers and their varied impeedance rating? Could it just be the speakers that are a bit strong in the midrange?
[/b]
All speakers have an impedance curve which varies.
Speakers usually have a 'nominal' or 'average' impedance rating, this isn't fixed, as impedance varies with frequency.
A 8 ohm speaker may dip as low as 6-7 ohms and go as high as 20-30 ohms at different frequencies, neither of which is a problem, it just is that way it is.

As far as your amplification is concerned, make sure you try everything on your shopping list at home in your system.
You may find the differences are smaller than expected in some instances.

I would also first consider just a 2 channel pawer amp, rather than an integrated or changing the whole AVR for seperates.
Adding a single outboard power amp will yield the greatest benefits for a single item, as it is the power amp stages of AVR's where the most corners are cut. It's much easier and cheaper to produce an adequate pre-stage than a power amp stage.
A 2 channel power amp will have the best WAF factor, and it will also benefit HT viewing as the HK will only need to drive the center and surrounds. It will also be the most cost effective.

You also haven't mentioned what kind of CD player you're using, as it could be this which is the limiting factor in your system.

The room also plays an enormous role in any audio system, so perhaps some treatments are also in order.

Rick.

[Drizt]

All speakers have an impedance curve which varies.
Speakers usually have a 'nominal' or 'average' impedance rating, this isn't fixed, as impedance varies with frequency.
A 8 ohm speaker may dip as low as 6-7 ohms and go as high as 20-30 ohms at different frequencies, neither of which is a problem, it just is that way it is.

As far as your amplification is concerned, make sure you try everything on your shopping list at home in your system.
You may find the differences are smaller than expected in some instances.

I would also first consider just a 2 channel pawer amp, rather than an integrated or changing the whole AVR for seperates.
Adding a single outboard power amp will yield the greatest benefits for a single item, as it is the power amp stages of AVR's where the most corners are cut. It's much easier and cheaper to produce an adequate pre-stage than a power amp stage.
A 2 channel power amp will have the best WAF factor, and it will also benefit HT viewing as the HK will only need to drive the center and surrounds. It will also be the most cost effective.

You also haven't mentioned what kind of CD player you're using, as it could be this which is the limiting factor in your system.

The room also plays an enormous role in any audio system, so perhaps some treatments are also in order.

Rick. [/b]

If he can not afford a dedicated pre-amp and dedicated power amp (i.e seperates) then his best bet would be to get an integrated hifi amp with a ht bypass. From what i have experienced AVRs are generally best avoided in 2ch systems, even if only used as a pre..

[alebonau]

If he can not afford a dedicated pre-amp and dedicated power amp (i.e seperates) then his best bet would be to get an integrated hifi amp with a ht bypass. From what i have experienced AVRs are generally best avoided in 2ch systems, even if only used as a pre..
[/b]

couldnt agree more.

[Rick]

If he can not afford a dedicated pre-amp and dedicated power amp (i.e seperates) then his best bet would be to get an integrated hifi amp with a ht bypass. From what i have experienced AVRs are generally best avoided in 2ch systems, even if only used as a pre..
[/b]Maybe, maybe not, the HK is a pretty decent sounding unit and all systems react different to different things.
He already stated that it may be over complicated for the WAF, so in this instance he may be better off with a power amp which should be able to be switched on via the AVR.
Sometimes compromises must be made.

Rick.

[alebonau]

Cam,
I think you will reap huge benefits by going seperates. Most AVRs don't do 2 channel very well. I recommend you try out some integrateds with HT bypass - eg: MF A3.5, Arcam A90 (I think) etc. Maybe a friendly store in Perth might let you try one at home for a few days?

Cheers,

Paul
[/b]

I think Pauls suggestion was the best here.

I've owned HK AVRs for the last 8 years now and demoed a few in that time as well upto the latest HK7300 in getting my current HK AVR. The HK AVRs like the NADs and rotels have solid amp stages, are better than your average denon or yam AVR for 2ch but do feel they can bettered by equivalent value dedicated 2ch amps, particularly because of the benefit brought from the better pre stage.

If you can borrow a 2ch integrated like the MFa3.5, CA840A or Arcam A90 and say an equivalent money power amp. eg the arcam p90 (http://www.tivolihifi.com.au/index.php?main_page=index&cPath=1_17), you'll soon know of the benfits brought to the 2ch side by either option in your system. And be able to have some time with both option to explore the WAF side as well.

Well worth demoing anyways, to make sure the particular aspect on how your system "lacks refinement in the midrange area at decent 2ch listening levels" is infact improved on or rectified with whatever upgrade you might be considering.

[Drizt]

Maybe, maybe not, the HK is a pretty decent sounding unit and all systems react different to different things.
He already stated that it may be over complicated for the WAF, so in this instance he may be better off with a power amp which should be able to be switched on via the AVR.
Sometimes compromises must be made.

Rick.
[/b]

Have to disagree again rick. An integrated amp with ht bypass is the simplest thing to implement and easily mastered by she who must be obeyed. All one has to do is press the "HT BYPASS" button when you want to watch movies and then bobs your aunty, everything works as it used to.

The pre in a integrated hifi amp is vastly superior to that found in an avr.

This could be made even simplier with a programmable remote like a logitech 880 harmony. then all you have to do is press one button and it will do everythign for you.

Although. If he later plans on buying a dedicated Pre-Amp with a HT bypass then by all means get a power amp for now, and then upgrade later.

But if he has no intention of getting a dedicated Pre at a later date, then i would definately recommend an integrated amp.

[Rick]

Have to disagree again rick. An integrated amp with ht bypass is the simplest thing to implement and easily mastered by she who must be obeyed. All one has to do is press the "HT BYPASS" button when you want to watch movies and then bobs your aunty, everything works as it used to.

The pre in a integrated hifi amp is vastly superior to that found in an avr.

This could be made even simplier with a programmable remote like a logitech 880 harmony. then all you have to do is press one button and it will do everythign for you.

Although. If he later plans on buying a dedicated Pre-Amp with a HT bypass then by all means get a power amp for now, and then upgrade later.

But if he has no intention of getting a dedicated Pre at a later date, then i would definately recommend an integrated amp.
[/b]
We'll just have to agree to disagree Drizt, I've done enough installations of this type of thing to recognise what the WAF will tolerate.
You need to remember it's not what you or I personally think is acceptable, it's what the purchaser thinks is acceptable.
And from MY experience, I feel a power amplifier is this purchasers better choice given the limited knowledge of his system.
More detailed information may provide us with more clues.

Rick.

[Spearmint]

Drizt I guess you are one of the fortunate few to have an understanding and interested partner with regards to your HT.




So I'd basically be running the intergrated separately for most sources and then using it in HT bypass mode with the pre-outs from the HK amp when using surroud.

Hmm - possibly a cost effective solution, but sounds quite complicated to operate for the WAF.

[/b]

From this reply I also read confusion from Caminperth as well.

Another thing to consider here is box count, and while using a either a 2ch pre or integrated will have benefits they are also required to be on display and require a separate volume control on the remote.

The addition of a power amp being operated via a 12v trigger means that it can be mounted out of sight.

[ramius]

Caminperth

Did you ever make any progress with this? I am interested as i have the BP20s and have similar concerns with harshness at high volume. I am more than happy with the sound (mainly used for HT) but at around -5dB from reference they become quite harsh (in fact harshness is being kind - more like distortion).

For the record i am also running DefTech for centre and rears with a Sony TAE-9000es pre and Denon POA-2800 2x200w amps all round. I have no idea whether the problem is related to amp, speaker, integration of the pre/pro or i just expect too much. The DefTechs are supposed to be easy to drive but i have also heard the opposite. They are also said to be particularly good at high volumes - but i am not hearing it.

Cheers

Bill