Lack of 2.1 support is grinding my gears

[coonmanx]

Maybe this doesn't accomplish everything that you want but it is definitely designed with 2.1 in mind...

Fosi Audio BT30D Pro Bluetooth Stereo Audio Receiver Amplifier Mini HiFi Home | eBay

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[Timcognito]

Yes it does but it only controls the feq. that go to the sub woofer & all feq. still go the mains, it's simply a 2 feq filter for the sub output. My thought is that a true hi pass/low pass filter or some type of crossover will get the real low bass freq. out of mains and let the sub handle those.

Wait, wasn't I just told what you are saying was bad and led to some timing issues? I'm no expert and confused. The guy just wants to try a sub with $2400 AVR. Did Marantz screw up?

 

[Yorkshire Mouth]

Yes it does but it only controls the feq. that go to the sub woofer & all feq. still go the mains, it's simply a 2 feq filter for the sub output. My thought is that a true hi pass/low pass filter or some type of crossover will get the real low bass freq. out of mains and let the sub handle those.

Yes, as most subwoofers have their own crossover, its use is fairly limited.

 

[mdsimon2]

Last I read, setting the subwoofer LPF applies an identical frequency/slope HPF to the powered output. This will not result in good sub/main integration as it ignores impact of the main speaker roll-off in the crossover.

Cheers. Where did you read that?

Originally here -> https://forum.wiimhome.com/threads/wiim-amp.1322/page-7#post-19617.

Once the sub-out is connected, you have the ability to set the cut-off frequency. This adjustment will subsequently impact the powered output to align with the chosen cut-off frequency. Thank you!

Also, here -> https://forum.wiimhome.com/threads/my-wiim-amp-experience.1931/

The crossover frequency also acts as a high pass filter with the low frequencies going to the subwoofer, and only the higher frequencies going to the speakers as already been answered both in Darko’s article and here in the forum by @onlyoneme.

Michael

 

[Yorkshire Mouth]

Originally here -> https://forum.wiimhome.com/threads/wiim-amp.1322/page-7#post-19617.



Also, here -> https://forum.wiimhome.com/threads/my-wiim-amp-experience.1931/



Michael

Thank you.

Please expand on why this is an issue.

 

[Timcognito]

Yes, as most subwoofers have their own crossover, its use is fairly limited.

Yes all the subwoofer developers put a lot more controls in the sub. Maybe they are just selling snake oil and don't understand what they are doing. I think somewhere in this post there is a lot over thinking of a old and common issue.

 

[levimax]

Yes all the subwoofer developers put a lot more controls in the sub. Maybe they are just selling snake oil and don't understand what they are doing. I think somewhere in this post there is a lot over thinking of a old and common issue.

Poor subwoofer integration is certainly a long standing issue but putting controls in the sub woofer instead of upstream in front of both the mains amp and subwoofer amp do not help things and probably confuse a lot of people as they think they are doing everything correctly but they are missing 2 huge issues of not high passing the mains and not being able to time align the mains and the sub. It looks like the Wiim amp does thing correctly but the Marantz 40n, where the sub-outs appear to be only a low pass filtered output and without pre-amp out and amp-in capability it seems to be very sub-optimal for subwoofers.

 

[mdsimon2]

Thank you.

Please expand on why this is an issue.

All speakers have acoustic high pass behavior on the low end, sealed speakers have 2nd order (12 db/oct) and ported speakers have 4th order (24 db/oct) roll-off.

Let's say you have a sealed speaker with LR2 @ 60 Hz acoustic high pass behavior, and you add an electrical LR2 @ 80 Hz HPF to this speaker and a matching electrical LR2 @ 80 Hz LPF to the sub. Your speaker now has 4th order acoustic high pass behavior (combination of acoustic LR2 @ 60 Hz + electrical LR2 @ 80 Hz) and your sub will roughly have 2nd order acoustic low pass behavior. This will result in poor integration between your main speakers and subwoofer due to poor phase matching.

Note, even the acoustic high pass behavior of the subwoofer will result in some integration issues if not considered in the main speaker. Ideally you would also add an additional HPF to the main speaker that matches the subwoofer acoustic high pass behavior.

Linkwitz models some of these integration issues (including delay which we have not discussed) here -> https://www.linkwitzlab.com/frontiers_5.htm.

Michael

 

[Timcognito]

Thanks for the responses to clarify this. Doesn't the "upstream" filter in LFE compensate for those issues and what about DSP in $2400 Marantz AVR

 

[Yorkshire Mouth]

All speakers have acoustic high pass behavior on the low end, sealed speakers have 2nd order (12 db/oct) and ported speakers have 4th order (24 db/oct) roll-off.

Let's say you have a sealed speaker with LR2 @ 60 Hz acoustic high pass behavior, and you add an electrical LR2 @ 80 Hz HPF to this speaker and a matching electrical LR2 @ 80 Hz LPF to the sub. Your speaker now has 4th order acoustic high pass behavior (combination of acoustic LR2 @ 60 Hz + electrical LR2 @ 80 Hz) and your sub will roughly have 2nd order acoustic low pass behavior. This will result in poor integration between your main speakers and subwoofer due to poor phase matching.

Note, even the acoustic high pass behavior of the subwoofer will result in some integration issues if not considered in the main speaker. Ideally you would also add an additional HPF to the main speaker that matches the subwoofer acoustic high pass behavior.

Linkwitz models some of these integration issues (including delay which we have not discussed) here -> https://www.linkwitzlab.com/frontiers_5.htm.

Michael

Thanks, that’s appreciated.

I’d still say that this is an issue dwarfed by the advantages of (a) taking the stress off the amp and (b) not playing the full range of frequencies (as far as they’re able to reproduce them) on the mains and sub simultaneously.

As I say, we shouldn’t make the perfect the enemy of the good.

 

[LouB]

Wait, wasn't I just told what you are saying was bad and led to some timing issues? I'm no expert and confused. The guy just wants to try a sub with $2400 AVR. Did Marantz screw up?

The Marantz model 40n is not an AVR it's a 2.1 channel amp with an HDMI input. I'm sure there AVR's are a completely different design.
Overall I feel this is a very simple concept (but just no easy way around it) the way I see it is, adding a sub to a 2 channel system and still sending all the low freq. to the mains is not ideal & you need some way to fix that weather its a hi/low pass filter in the amp or some type of added device that will separate the freq.

 

[Timcognito]

The Marantz model 40n is not an AVR it's a 2.1 channel amp with an HDMI input. I'm sure there AVR's are a completely different design.
Overall I feel this is a very simple concept (but just no easy way around it) the way I see it is, adding a sub to a 2 channel system and still sending all the low freq. to the mains is not ideal & you need some way to fix that weather its a hi/low pass filter in the amp or some type of added device that will separate the freq.

Thank you for everyone's patience with me and the OP too. I understand now what the issue has little to do with the subwoofer. But instead, the AVR's amp's lack of a high pass filter to the speakers for proper integration which must take place some where before the separate speaker inputs independent of sub. Seems like Marantz should have known this if they are offering subwoofer connectivity. It may not be ideal but adding a sub and keeping the low pass low (guessing < 50 Hz) going to sound bad?

 

[Weeb Labs]

I find this and the many similar boards like this, this and this to be perfectly adequate for my 2.1 needs. They are extremely functional and don't have to replace your existing DAC if you add a SPDIF expansion for the main channels. They are not particularly fancy or designed to appeal to conventional audiophiles but they work well.

 

[mdsimon2]

Thanks, that’s appreciated.

I’d still say that this is an issue dwarfed by the advantages of (a) taking the stress off the amp and (b) not playing the full range of frequencies (as far as they’re able to reproduce them) on the mains and sub simultaneously.

As I say, we shouldn’t make the perfect the enemy of the good.

I get it, we all have areas we would be comfortable compromising in if needed.

I much prefer a device like the miniDSP 2x4HD (or the ADAU based ali express boards @Weeb Labs posted) which has all of the x-over, PEQ and delay capabilities needed for proper sub integration even though it has slightly lower DAC performance. However, I understand the appeal of an all-in-one streamer, DAC, amp, DSP that the Wiim offers.

I just think it is a bit unfair to hold the Wiim amp up as an example given its very compromised DSP capabilities and other growing pain issues (humming noise).

Michael

 

[312elements]

This seems to be a DAC issue to me. Am I correct in assuming that for a DAC to manage something like a high pass and low pass crossover we would need 2x the converters? And then also some kind of SHARK processor or similar to manage filters? Then we would at minimum want some kind of web interface for controlling the filters. It’s almost 2024, that should probably be an app. While we’re at it, throw in 10 bands of PEQ? Would it be hard to add Roon endpoint support? What about BT? The feature creep gets real and we probably don’t want to sacrifice the analog stage either. Oh and what about the vinyl crowd. We need ADC too.

Minidsp flex is looking pretty affordable and attractive at this point. For the record, I’m all for a device like this. It’s the RIGHT way to do it. Adding features like this to an amplifier is a giant leap in the wrong direction. Give it a little more time. I could see one of the big DAC companies like topping or smsl taking a big swing at something like this, but it’s going to have a four figure price tag.

 

[Timcognito]

This seems to be a DAC issue to me. Am I correct in assuming that for a DAC to manage something like a high pass and low pass crossover we would need 2x the converters? And then also some kind of SHARK processor or similar to manage filters? Then we would at minimum want some kind of web interface for controlling the filters. It’s almost 2024, that should probably be an app. While we’re at it, throw in 10 bands of PEQ? Would it be hard to add Roon endpoint support? What about BT? The feature creep gets real and we probably don’t want to sacrifice the analog stage either. Oh and what about the vinyl crowd. We need ADC too.

Minidsp flex is looking pretty affordable and attractive at this point. For the record, I’m all for a device like this. It’s the RIGHT way to do it. Adding features like this to an amplifier is a giant leap in the wrong direction. Give it a little more time. I could see one of the big DAC companies like topping or smsl taking a big swing at something like this, but it’s going to have a four figure price tag.

Its here look at Lyngdorf TDAI 1120 or miniDSP SHD Power with super good test specs

SoundStage! Hi-Fi | SoundStageHiFi.com - miniDSP SHD Power Integrated Amplifier-DAC

www.soundstagehifi.com

 

[Romario]

Interesting read. I was wondering if a wiim mini conected to the sub only can be configured for the peq low frequencies only while the wiim pro in the main system can use it"s own peq for the LR speakers. When paired you can calibrate the delay to line up. The sub is then wireless.

If I disrupted the conversation, please forgive me.

 

[Timcognito]

Two good short reads on things that have been discussed here. The second is more on topic.

SoundStage! Access | SoundStageAccess.com (GoodSound.com) - Integrating a Single Subwoofer into a Two-Channel System for Beginners

www.soundstageaccess.com

SoundStage! Access | SoundStageAccess.com (GoodSound.com) - Integrating a Single Subwoofer into a Two-Channel System . . . for Those Unafraid to Take Measurements, Fiddle with Filters, and Apply EQ

www.soundstageaccess.com

 

[Chrispy]

Yes, as most subwoofers have their own crossover, its use is fairly limited.

Actually most subwoofers only have a low pass filter labeled as crossover.....

 

[EDMoser]

Sony STR-DH590 is a 5.2 channel AVR that you can set the speaker config from 2.0 to 5.1. It has a selectable HPF from 40-160 Hz for the mains. It is $250 USD and sounds transparent to my ears. Experiment with it and see if you can hear a difference between it and separates. Return it if not satisfied.

Don't care for Sony? - There are other sub-$500 AVRs that will do a 2.1 system easily.

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