Vintage yamaha dsp a2070 help

[lucid]

Great information and much appreciated. The subs are rated at 400rms at 4ohms and were in sealed boxes. They’re originally car subs, Pioneer TS-W306c to be exact. As they’re sitting there doing nothing I want to make use of them for home theatre/music purposes and thought a a2070 at around £70 might give me decent results.

Looking more into it I’m not even sure if that would work as I don’t know if the a2070 has a crossover for the power frequencies that a sub would need?

I was also looking at the behringer a800 but won’t be spending £250 for a amp that was apparently around £160 just a couple years ago!

Thank you for you help once again.

IIRC, the DSP-A2070 doesn't have crossover, sub volume and phase adjustments.... but you don't need them in the 2070 because your Marantz SR7011 has them.

I know you said you're new to this, so let's talk about what happens when we set up an AV receiver with a conventional powered sub, then you can see how things would work with your proposed setup.

We'll pretend that you've bought an AV sub. On the back you'll generally have three controls.These are volume, crossover frequency, and phase.

Volume dictates how hard the amp will run and the volume that the sub produces.

Crossover Frequency adjusts the blend point between the main speakers and the sub.

Phase adjusts the timing of the bass pulses relative to the main speakers.

If we imagine you're doing a setup with a conventional AV sub and your SR7011, then the amp manual will direct you to set volume at 50%, crossover to maximum, and phase to 0 degrees. What the effects of these settings are is as follows...

Volume @ 50% - it's a best guess starting point for how much power will be required from the sub to adequately pressurise the room. When you run the wizard the amp will adjust its own subwoofer signal level up or down to get as close to a correct level as possible.

Crossover at maximum - it's basically disabling the sub's control of this and handing it all to the AV receiver

Phase at 0 degrees - the nearest approximation of a neutral point


You've probably worked it out for yourself now that a lot of the signal processing has been done before the signal has reached the sub. That makes sense if you think about it. Let's take crossover frequency.

A set of front L&R speakers might work best with an 80Hz crossover point, but maybe the centre is happier at 90 or 100Hz, and the dinky surrounds need 120Hz. How would the single crossover control provide settings for all 5 speakers? It can't. This is part of the bass management that the AV receiver does. It's the same with volume for each individual speaker too.

Bringing this back to your plan, the SR7011 is going to be in the driving seat for volume, crossover and phase. All the 2070 need do is provide the muscle.

Comprender?

 

[5rivers79]

IIRC, the DSP-A2070 doesn't have crossover, sub volume and phase adjustments.... but you don't need them in the 2070 because your Marantz SR7011 has them.

I know you said you're new to this, so let's talk about what happens when we set up an AV receiver with a conventional powered sub, then you can see how things would work with your proposed setup.

We'll pretend that you've bought an AV sub. On the back you'll generally have three controls.These are volume, crossover frequency, and phase.

Volume dictates how hard the amp will run and the volume that the sub produces.

Crossover Frequency adjusts the blend point between the main speakers and the sub.

Phase adjusts the timing of the bass pulses relative to the main speakers.

If we imagine you're doing a setup with a conventional AV sub and your SR7011, then the amp manual will direct you to set volume at 50%, crossover to maximum, and phase to 0 degrees. What the effects of these settings are is as follows...

Volume @ 50% - it's a best guess starting point for how much power will be required from the sub to adequately pressurise the room. When you run the wizard the amp will adjust its own subwoofer signal level up or down to get as close to a correct level as possible.

Crossover at maximum - it's basically disabling the sub's control of this and handing it all to the AV receiver

Phase at 0 degrees - the nearest approximation of a neutral point


You've probably worked it out for yourself now that a lot of the signal processing has been done before the signal has reached the sub. That makes sense if you think about it. Let's take crossover frequency.

A set of front L&R speakers might work best with an 80Hz crossover point, but maybe the centre is happier at 90 or 100Hz, and the dinky surrounds need 120Hz. How would the single crossover control provide settings for all 5 speakers? It can't. This is part of the bass management that the AV receiver does. It's the same with volume for each individual speaker too.

Bringing this back to your plan, the SR7011 is going to be in the driving seat for volume, crossover and phase. All the 2070 need do is provide the muscle.

Comprender?

Thanks you for the detailed response and putting it down simply for me. It’s a great learning experience that’s for sure.

I’m now leaning towards getting a stereo power amp instead maybe as you suggested that the Yamaha may not be powerful enough to power the subs.

I know it’s off topic but how do power amps such as Behringer, W Audio, Inter M differ to home cinema amps like Emotiva that cost much much more?

Thanks

 

[lucid]

The fidelity requirements for powering a sub are less stringent than for powering the main channels. Class D amplification is common. This gives a lot of power and runs cool compared to the same manufacturing budget spent on a big transformer and traditional Class A/B transistor design. Subs, sound bars, mains powered smart speakers, those crappy all-in-one DVD/Blu-ray home cinema kits, small shelf-stereos etc... They all use various qualities of switch-mode power supply and Class D amplification to either keep costs and power consumption down (they're relatively energy efficient) or to pack a lot of power into a fairly small chassis.

The low-cost / high-power route is popular with budget DJ / PA amp users. For someone spinning the records at home, or who does the odd commercial gig, then Behringer in the past and some brands seem to offer a lot of Watts for very little money. What's not to like? The reality though is often that the numbers are, to be blunt, fake. They're based on theoretical maximums and double-counting.

For example, if you think about the movement of a speaker cone, it goes in and out. I's like a piston pumping the air. The signal driving that piston also has a forward and reverse phase. We call this an AC signal. (AC - Alternating Current.) Just as a speaker cone can't be going out at the same time as it's going on then the AC waveform for the music can't be pushing and pulling at the same time. It's doing one or the other. However, if you want to make it look like your amp is more powerful than it really is then you count both phases and treat them as if they're happening at the same time. Other tricks include measuring the peak rather than the RMS power, and measuring at a very high distortion rate (10% THD) compared to Hi-Fi amps (<0.01% THD). There's a whole host of other tricks and connivances.

'How do they get away with this?' - partly it's because there are loopholes in how technical specs can be reported. Other reasons include the lack of technical knowledge within the consumer field and a little bit of sleight of hand.

The average consumer doesn't fully understand the difference between RMS and Peak Music Power. They've no concept of how measuring at 10% THD vastly inflates the power figure compared to 0.01% THD. Then there's measuring at 1kHz rather than 20Hz-20kHz, or quoting for a single channel driven and letting the consumer presume (incorrectly, as it happens) that running two or 5 or 7 channels will result in a simple multiplication of the single channel power figure.

Behringer had a model range called i-nuke. Within the industry they were renamed i-puke. The specs were almost a work of fantasy. Something similar happened with some of their other models. There's a review site called Audio Science Review where they did proper testing and measurements of the Behringer NX1000D. This claims to do 2 x 300W into 4 Ohms. The reality is a max of around 180W per channel. What's curious too is that the power into 8 Ohms drops way more than expected. It more than halves. Just 78W/ch. That's the opposite of what might be expected with a Hi-Fi grade Class D amp.

https://www.audiosciencereview.com/forum/index.php?threads/behringer-nx1000d-review-stereo-amplifier.24908/

Compare and contrast with the Crown XLS1502. This is a well respected PA brand. The internal designs are good. They've been in business a long time and have a good reputation. This still isn't up to Hi-Fi standards to replace a NAD / Rotel / Audiolab etc power amp for main speaker use, but could quite easily run one or two passive subs. https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-crown-xls-1502-amp.6062/

It's not all plain sailing for Emotiva either. When the XPA-DR2 ($1700) was reviewed back in summer of 2021 it didn't do that well.
https://www.audiosciencereview.com/forum/index.php?threads/emotiva-xpa-dr2-review-stereo-power-amplifier.25067/

The moral of the story here is take nothing at face value. Dig into the story behind the products before you lay out a chunk of cash.

 

[5rivers79]

The fidelity requirements for powering a sub are less stringent than for powering the main channels. Class D amplification is common. This gives a lot of power and runs cool compared to the same manufacturing budget spent on a big transformer and traditional Class A/B transistor design. Subs, sound bars, mains powered smart speakers, those crappy all-in-one DVD/Blu-ray home cinema kits, small shelf-stereos etc... They all use various qualities of switch-mode power supply and Class D amplification to either keep costs and power consumption down (they're relatively energy efficient) or to pack a lot of power into a fairly small chassis.

The low-cost / high-power route is popular with budget DJ / PA amp users. For someone spinning the records at home, or who does the odd commercial gig, then Behringer in the past and some brands seem to offer a lot of Watts for very little money. What's not to like? The reality though is often that the numbers are, to be blunt, fake. They're based on theoretical maximums and double-counting.

For example, if you think about the movement of a speaker cone, it goes in and out. I's like a piston pumping the air. The signal driving that piston also has a forward and reverse phase. We call this an AC signal. (AC - Alternating Current.) Just as a speaker cone can't be going out at the same time as it's going on then the AC waveform for the music can't be pushing and pulling at the same time. It's doing one or the other. However, if you want to make it look like your amp is more powerful than it really is then you count both phases and treat them as if they're happening at the same time. Other tricks include measuring the peak rather than the RMS power, and measuring at a very high distortion rate (10% THD) compared to Hi-Fi amps (<0.01% THD). There's a whole host of other tricks and connivances.

'How do they get away with this?' - partly it's because there are loopholes in how technical specs can be reported. Other reasons include the lack of technical knowledge within the consumer field and a little bit of sleight of hand.

The average consumer doesn't fully understand the difference between RMS and Peak Music Power. They've no concept of how measuring at 10% THD vastly inflates the power figure compared to 0.01% THD. Then there's measuring at 1kHz rather than 20Hz-20kHz, or quoting for a single channel driven and letting the consumer presume (incorrectly, as it happens) that running two or 5 or 7 channels will result in a simple multiplication of the single channel power figure.

Behringer had a model range called i-nuke. Within the industry they were renamed i-puke. The specs were almost a work of fantasy. Something similar happened with some of their other models. There's a review site called Audio Science Review where they did proper testing and measurements of the Behringer NX1000D. This claims to do 2 x 300W into 4 Ohms. The reality is a max of around 180W per channel. What's curious too is that the power into 8 Ohms drops way more than expected. It more than halves. Just 78W/ch. That's the opposite of what might be expected with a Hi-Fi grade Class D amp.

https://www.audiosciencereview.com/forum/index.php?threads/behringer-nx1000d-review-stereo-amplifier.24908/

Compare and contrast with the Crown XLS1502. This is a well respected PA brand. The internal designs are good. They've been in business a long time and have a good reputation. This still isn't up to Hi-Fi standards to replace a NAD / Rotel / Audiolab etc power amp for main speaker use, but could quite easily run one or two passive subs. https://www.audiosciencereview.com/forum/index.php?threads/review-and-measurements-of-crown-xls-1502-amp.6062/

It's not all plain sailing for Emotiva either. When the XPA-DR2 ($1700) was reviewed back in summer of 2021 it didn't do that well.
https://www.audiosciencereview.com/forum/index.php?threads/emotiva-xpa-dr2-review-stereo-power-amplifier.25067/

The moral of the story here is take nothing at face value. Dig into the story behind the products before you lay out a chunk of cash.

I have been looking at the A800 from Behringer but seemed to only cost £150 last year compared to £280 now.

Power levels seem to be decent too according to this review but can’t find anything on the used market and don’t want to spend hundreds at this point to get the subs running.

Behringer A800 Stereo Amplifier Review

This is a review and detailed measurements of the Behringer A800 Class D Stereo Amplifier. It is on kind loan from a member. The A800 costs US $299 including free shipping from multiple sites. The member who loaned it me has done a youtube video of it which you can see by clicking on this...

audiosciencereview.com

I wonder if the Yamaha dsp2070 comes close to pushing it’s stated numbers and if I should just stick to that for now.

 

[lucid]

The 2070 and the 3090 are both monster amps. They are rated conservatively and deliver tonnes of seemingly bottomless power for stereo use. I've had good examples of each here. They're a lot of fun.

What I haven’t done though is what you're planning, which is to run them purely for subwoofer bass. I can't predict exactly how they'll behave when trying to keep up with the 7011 running the main speakers. I think a lot depends on how loud you routinely run your system, and the size of your room, and whether those subs are run in ported or sealed enclosures.

I have a couple of REL Stadium II subs here. They're only 100 Watts a piece and based on 10" drivers, but the cabs are large ported boxes similar in size to BK Monoliths (BK used to manufacture for REL). Just one in my room - a shade over 12×15, but opens into a similarly sized room beyond - is enough to create thuds and rumbles that can be felt through the floor with the main system volume at -35dB.

In all honesty, I think you've just got to suck it and see.

The two Yams I sold for my customer (yes, he owned both!) were in mint condition, boxed and with manuals etc. IIRC, the 2070 went for £300 and the 3090 for closer to four. I have seen less loved examples go for far lower prices.

People who don't understand these simply dismiss them on the basis that they're 'just old AV amps', but they're missing a trick. Their loss is your gain.

 

[5rivers79]

The 2070 and the 3090 are both monster amps. They are rated conservatively and deliver tonnes of seemingly bottomless power for stereo use. I've had good examples of each here. They're a lot of fun.

What I haven’t done though is what you're planning, which is to run them purely for subwoofer bass. I can't predict exactly how they'll behave when trying to keep up with the 7011 running the main speakers. I think a lot depends on how loud you routinely run your system, and the size of your room, and whether those subs are run in ported or sealed enclosures.

I have a couple of REL Stadium II subs here. They're only 100 Watts a piece and based on 10" drivers, but the cabs are large ported boxes similar in size to BK Monoliths (BK used to manufacture for REL). Just one in my room - a shade over 12×15, but opens into a similarly sized room beyond - is enough to create thuds and rumbles that can be felt through the floor with the main system volume at -35dB.

In all honesty, I think you've just got to suck it and see.

The two Yams I sold for my customer (yes, he owned both!) were in mint condition, boxed and with manuals etc. IIRC, the 2070 went for £300 and the 3090 for closer to four. I have seen less loved examples go for far lower prices.

People who don't understand these simply dismiss them on the basis that they're 'just old AV amps', but they're missing a trick. Their loss is your gain.

I think I might just give it a shot if it’s still available. The two subs I have are in sealed enclosures, but since they are really car subs they are in small enclosures designed for 12 inch subs.

The home cinema setup is in a bedroom that measures 2.7m high x 3.5m wide x 5ish m long. Not a massive room but not particularly small either.

 

[5rivers79]

Out of curiosity do you know of Inter M amps? A local shop has a used 500 Plus model for £100 and claims to be ‘500rms’ at 4ohms so a theoretical 250 into each channel.

 

[lucid]

I'm aware of the Inter M brand, and AFAIK the products were/are supplied with the split 5 year warranty (3yrs P&L, then 2yrs parts only) so that's a reasonable indicator of their confidence in build quality. IDK though if anyone has done any in-depth testing of their amps to see if the numbers stack up. The other complication could be that, like Behringer, the performance of some models is better than others.

If this is the amp I'm thinking of at £99, then it comes with a 12 month warranty. You'd need to look at the Ts & Cs of that, but at least you have some confidence that there's back-up for a year if something goes wrong. I dare say too that you could run it for a year and then sell it on with little or no loss.

 

[5rivers79]

I'm aware of the Inter M brand, and AFAIK the products were/are supplied with the split 5 year warranty (3yrs P&L, then 2yrs parts only) so that's a reasonable indicator of their confidence in build quality. IDK though if anyone has done any in-depth testing of their amps to see if the numbers stack up. The other complication could be that, like Behringer, the performance of some models is better than others.

If this is the amp I'm thinking of at £99, then it comes with a 12 month warranty. You'd need to look at the Ts & Cs of that, but at least you have some confidence that there's back-up for a year if something goes wrong. I dare say too that you could run it for a year and then sell it on with little or no loss.

Thank you once again for the detailed response.

Looks like I may go for the inter m amp..but it has two inputs, one for each channel. Does this mean that I can’t connect one cable to my Marantz avr to get the signal to it? Would I need some kind of splitter as one of the sub outs has my Mission Sub connected to it and the second is the free one that I wanted to use for the Pioneers? Thanks

 

[lucid]

Thank you once again for the detailed response.

Looks like I may go for the inter m amp..but it has two inputs, one for each channel. Does this mean that I can’t connect one cable to my Marantz avr to get the signal to it? Would I need some kind of splitter as one of the sub outs has my Mission Sub connected to it and the second is the free one that I wanted to use for the Pioneers? Thanks

Use a Y splitter cable on the second sub out on the 7011. Take the two signals to the Inter-M amp to run the two Pioneer subs.

 

[hornetstinger]

Are you eqing the subs?

 

[5rivers79]

Are you eqing the subs?

Wouldn’t the Marantz AVR help with that?

 

[lucid]

Wouldn’t the Marantz AVR help with that?

The Marantz will do the basics of sub set-up, but @hornetstinger is talking about a whole other level. He'd like to take you down a rabbit hole where you'll spend £400-£800 on a fancy box of tricks which applies special EQ curves to each sub based on readings from a £100 calibrated mic connected via USB to a laptop running some sound measuring software.

Now, all of that is absolutely valid.... IF... you're spending big Buck$$$ on beefy subs. But that's not you. He hasn't quite twigged that this is you throwing a couple of extra non-HT subs in just for a laugh to see what happens.

At some point in the future you may decide to follow Alice. I'm about to eat the cake or drink the potion (can't recall which is which) if I can get one of the more tweaked mics that's calibrated down to 10Hz rather than just 20Hz. I already have dual matching subs which is one of the prerequisites to getting a decent result.

At this level, multiple subs isn't about sheer bass level. It's about getting an even dispersion through the room. This is a massive topic and pulls in stuff such as room treatment too. But that's not what you're doing yet. Maybe. One day. But not today.

 

[5rivers79]

The Marantz will do the basics of sub set-up, but @hornetstinger is talking about a whole other level. He'd like to take you down a rabbit hole where you'll spend £400-£800 on a fancy box of tricks which applies special EQ curves to each sub based on readings from a £100 calibrated mic connected via USB to a laptop running some sound measuring software.

Now, all of that is absolutely valid.... IF... you're spending big Buck$$$ on beefy subs. But that's not you. He hasn't quite twigged that this is you throwing a couple of extra non-HT subs in just for a laugh to see what happens.

At some point in the future you may decide to follow Alice. I'm about to eat the cake or drink the potion (can't recall which is which) if I can get one of the more tweaked mics that's calibrated down to 10Hz rather than just 20Hz. I already have dual matching subs which is one of the prerequisites to getting a decent result.

At this level, multiple subs isn't about sheer bass level. It's about getting an even dispersion through the room. This is a massive topic and pulls in stuff such as room treatment too. But that's not what you're doing yet. Maybe. One day. But not today.

Doesn’t the Audessey feature of the Marantz kinda do that itself? I definitely don’t want to spend that kinda money on my setup..I mean even my 8 inch mission sub makes my room rumble but as these pioneers were lying around I just want to throw them in the mix to get a bigger rumble lol.

 

[lucid]

Doesn’t the Audessey feature of the Marantz kinda do that itself? I definitely don’t want to spend that kinda money on my setup..I mean even my 8 inch mission sub makes my room rumble but as these pioneers were lying around I just want to throw them in the mix to get a bigger rumble lol.

It does, but as @hornetstinger has shown us numerous times, he's not happy unless a user is hemorrhaging cash to get bleeding edge solutions


You've got Audyssey XT32 in the 7011. There's a review of it from the ASR site. It comes out quite well, but tipping up for the mobile phone app is recommended in order to tweak some settings. Have a read of the review. It'll give you the pointers you need.

Have fun

 

[5rivers79]

Just got home after picking up the Yamaha 2070. Wow didn’t think it would be this heavy! Gives my Marantz a run for its money!

There’s a couple of scuff and dings on the top but the face itself looks very clean. Looking inside through the air vents it also looks very clean and dust free. Ended haggling down to £50 as there’s no box or manual..so all good as long as it works..( guy was waiting for me at the door with it ready to take ).

Next is how to get these subs and my Marantz connected to it. What would be the best way? Thanks

 

[5rivers79]

 

[lucid]

Next is how to get these subs and my Marantz connected to it. What would be the best way? Thanks

We've been through all that, in detail, in the posts further up.

Now you have the hear in front of you have another read, it will make more sense.

 

[5rivers79]

We've been through all that, in detail, in the posts further up.

Now you have the hear in front of you have another read, it will make more sense.

So a Y cable from the Marantz sub out to the one of the inputs such as “Phono” and then the output would be “Center” as it says 4ohm?

I understand how I’d connect it to a amp like the inter m but this with all its connections has me confused. Sorry.

 

[lucid]

So a Y cable from the Marantz sub out to the one of the inputs such as “Phono” and then the output would be “Center” as it says 4ohm?

I understand how I’d connect it to a amp like the inter m but this with all its connections has me confused. Sorry.

Yes, a Y splitter cable, one end at the Marantz and two at the Yamaha end, but Phono is for a record player. Don't use Phono.

Remove the bridging links and connect direct to Power amp in.

You just want to set this up as plain stereo POWER AMP, so you've got two channels (right and left, not centre) connected to the subs.

The manual for the Yamaha can be downloaded from Yamaha and a few other sites. Do that. Have a read.