Help needed with 2.1 system for music using current pm7200

[markw]

The key words in his post are "effectively repurposed". It's still an integrated amp, not a power amp. You will be going through two preamp stages which will pollute that pure 7200 sound you seem so intent on preserving.. Do you want this?

The same for the halo. It's a preamp well.

You might want to PM GIGEAR to solicit his input on this. I think I'm done here.

You might want to take a little time to get a grip on the signal flow of a stereo system and then a multi-channel AV system, and the functions of the basic component parts involved. It will help you understand what's going on here. Like many newbies, you're asking questions to which you need a little basic understanding of them in order to understand the answers.

 

[GIEGAR]

OK, last question (honest!). Earlier in this thread GIGEAR said:


Hi Alpha. You don't need to ditch the Marantz UK | PM7200.

For an economical, simple solution, what I recommend you do is get one of the "slim line" 5 channel Marantz AVR's. The current model is the Marantz UK | NR1504, but older models will also be fine. In addition to a subwoofer preout jack, these have L & R main channel preout jacks (AKA 2.1 preouts). With the smaller Marantz AVR, you’re not paying for amplification you don’t need and the form/finish is a fairly good match for the PM7200.

Hook up the sources you want to utilise the sub for (I presume all) to the AVR and let it do the signal processing and (digital) bass management. The AVR’s L & R main preouts then feed your PM7200 for amplification and the new powered sub is fed directly by the AVR's sub preout. The AVR effectively becomes the processor/preamp and the PM7200 is effectively re-purposed as a power amp.

As well as bass management, you will also benefit from the AVR's very good Audyssey MultEQ auto setup and EQ routine and the associated Dynamic EQ. Audyssey will accurately measure and set up your speaker distances (delays) and levels, suggest crossover frequencies and determine EQ filters for each channel. Of course, you can “opt out” of Audyssey’s EQ and processing at various tiers or disable it altogether if you choose.

Good luck and let us know if you have any questions.


How is it I can connect the NR1504 to my PM7200, but not connect a Halo P 5 to my PM7200?

Agghh! Apologies alphawave, I went back and had a look at this and my original advice was unmitigated crap!

I had taken a quick look at the PM7200 manual and saw that it had stereo analog inputs labelled "Processor In"; put 2 and 2 together and got the square root of bugger all!

As I stuffed this up, I owe you a bit of an explanation: These (and other) inputs on the PM7200 are in fact meant to receive very low level audio signals from source devices, as small as μV (microvolts) and the input sensitivity of these inputs is rated at 150mV (millivolts). On the other hand consumer line-level, which is applicable to preamp output levels, is referenced to -10dBV or 0.316Vrms. This means that if you connect preamp outputs to those inputs they will be receiving signals up to many thousands of times greater in strength than what they're designed for. The consequences of this could not be good, not the least of which would be sustained/severe clipping of the amplifier stages as the circuits are overloaded. Intuitively, all this makes sense too... you don't want/need two preamp stages in the signal chain.

Mark is correct, the PM7200 would have needed to have line-level inputs (or similar) to bypass it's processing/preamps and thus effectively turn it into a power amp. Thanks also to Mark for being gracious and not hanging me out to dry on all this.

I will go back and edit my original post "for the record". Apologies again for leading you astray.

 

[TLS Guy]

As I stated at the beginning, the only way for you to use a sub is from the speaker outputs of your Marantz, I told you this right at the beginning.

So you need a sub with speaker level inputs, or you need to use a speaker level to line converter.

The BK sub mentioned, uses a 10" Peerless woofer in an 18 lt sealed cabinet. The manufacturer quotes a -6db point of 17 Hz. However output is not specified.

That will require heavy equalization. So output will not be great. Output will be in the high 90 db range at best. So this sub will not shake the rafters.

 

[alphawave]

OK guys, thanks no damage done.

What will output be like if I go for the XLS400?

EDIT: wait a minute ... wiki says 90 - 95 db is the level at which hearing loss occurs with sustained listening ... surely that's a good enough output unless I'm missing something here

 

[TLS Guy]

OK guys, thanks no damage done.

What will output be like if I go for the XLS400?

EDIT: wait a minute ... wiki says 90 - 95 db is the level at which hearing loss occurs with sustained listening ... surely that's a good enough output unless I'm missing something here

You are, those measurements are taken at a meter. The spl. falls of by the square of the distance for speakers. A max output of 95 db at the speaker will be relatively modest. A decent sub is going to have an output is the 115 to 120 db range max output at 1 meter.

Don't forget the db scale is log. You need to go up 10db to double the perceived spl. So the sub under discussion will only make an impact in a small room. I don't know your room size and a lot of UK rooms are small. In a large room that sub would be pretty much useless.

And when it comes to subs, any open areas count. So if the room opens to another room or stairway, the sub has to pressurize the whole space. The whole space has to be taken into account. Open continuous spaces "bleed" bass like crazy.

 

[alphawave]

Hi Gents, sorry to bring this thread back up. After much deliberation I now have an Anthem MRX500 on its way (2nd hand, 5 months old - £600 seemed a decent price). So my PC will be going into that (I guess SPDIF to bypass the X-Fi Titanium HD DAC). This should make my choice of sub easier and I now have some decent bass management and room correction.

I'm just wondering whether my PM7200 is now surplus to requirements. I can see from GIGEAR and markw's posts a couple above that it will not be an option to go from the MRX500 to the processor in of the PM7200. But I also see that GIGEAR says:

Mark is correct, the PM7200 would have needed to have line-level inputs (or similar) to bypass it's processing/preamps and thus effectively turn it into a power amp.

Are the Tape and CD ins on the PM7200 not line level? Or do they go through the pre stage as well?

I'm hoping that the MRX will be fine sound quality wise but, as you may guess, I'm also thinking about hooking the two up together to see how they perform. But, I don't want to blow anything up or waste my time messing around if this ain't gonna work.

 

[markw]

Are the Tape and CD ins on the PM7200 not line level? Or do they go through the pre stage as well?

Yes, the both go through the preamp stage as well. Anything that goes through a volume control does. As I said earlier, it's time for you to get a little knowledge of the basic system flow.

 

[ski2xblack]

Why on earth would you want to even do that? The Anthem has higher rated power, yet you want to off-load to a lesser amp? (You wouldn't blow anything up feeding the Anthems pre outs to a line input of the Maranzz and using it as an amp, but it's simply a hare-brained idea. It's like stealing first base after hitting a double.)