MiniDSP 2x4 HD Connection with Dual REL S/3 SHO Subs

[ssanford69]

Hello all. I am new to the Hi-Fi world and I'm diving into this wonderful "sport" with great fervor. I trying to produce the best sound possible in my listening space using the system that I've peiced together over the past few years. To that end, I've downloaded REW and ordered the MiniDSP 2x4 HD to help.

I would absolutely love your input about know how to connect my system correctly. I have the Marantz SR7011 AVR running to a Parasound A21+ Power Amp. It drives the PSB Imagine T3 Towers. It also passes a "high level" signal through a set of Speakon cables to dual REL S/3 SHO Subs (these also have low level inputs). I use the sub pre-outs of the SR7011 for the LFE signal to the REL's. I hate to give up the High Level connections to the REL's because they "HIGHLY" recommend that everyone use them.

1. Is there a way to manage the bass and do room correction using the MiniDSP 2x4 while continuing to use the High Level REL connections from the power amp?
2. Is there another piece of equipment that I might consider to help acheive my goal? FYI ... I want to add a Music Server/Streamer/Ripper in the near future too (maybe the Innuos Zen Mk 3, the Cocktail Audio X50(D), or the NAD M50.2). So feel free to offer more input on my setup and new/additional equipment as you see fit.

I sincerely apologize if I'm jumping into this forum improperly. I know that most of you are experienced and well versed in the Hi-Fi language, so please forgive my ignorance and questions if they are out of place.

Thanks so much,
Scott

 

[Wayne A. Pflughaupt]

Welcome to the Forum!

This is pretty simple, really. You can connect the mini as seen in the diagram at the link below, and get full-range signal processing. The Speakon connection won’t change.

https://www.minidsp.com/images/documents/Product%20Brief-miniDSP%202x4%20HD.pdf

Regards,
Wayne

 

[ssanford69]

Thanks for the reply Wayne. I found this PDF when I was researching the miniDSP's. The diagram is the reason that I posed the question. REL says that you should NOT connect both the High-Level and Low-Level inputs on their subs at the same time. Here's the basic connection video for REL.

Fast forward to the 1:50 time stamp to see what I mean. Am I misunderstanding something?

 

[Wayne A. Pflughaupt]

There are a couple of options.

You can get two miniDSPs if you want full-range EQ – one for the mains and one for the subs.

Alternately, you could get a stereo to mono converter box and send the combined miniDSP low output to the REL’s LFE input.

Regards,
Wayne

 

[SeanK]

I had a REL subwoofer and I couldn't tell any difference between the Speakon connection and the RCA connection.

 

[ssanford69]

Thanks again Wayne. Also Sean for the input. I know that I'm showing my ignorance here, but I have to ask...

Would it be silly to run two of the miniDSP outputs to the low level inputs of the REL's. Then run my Marantz Pre-Outs to the LFE inputs of the REL's (I'm doing this now). In other words, I would be "skipping" the miniDSP for the LFE signal. but would it matter a lot if I did? I really appreciate your help fellas!

 

[Wayne A. Pflughaupt]

Sorry, there’s no way I can give an answer on that. Except to say that everyone else who doesn’t own this sub has had no problem getting great results EQIng via line level in front of the sub.

Regards,
Wayne

 

[ssanford69]

I'm so sorry Wayne. I don't mean to be so stupid, and I'm not questioning you or your expertise or anything like that. This is purely an ignorance thing on my part. In the end, it seems that I don't understand the the terminology and/or all the different cables and signals. I assume Line-Level and Low-Level are the same thing? Also, is there a difference between Low-Level/Line-Level and LFE? I was under the impression that LFE is a completely separate channel from the others and only carried information that was explicitly included in a movie soundtrack? My subs each have a single LFE input, two Low-Level inputs for Left and Right on each sub, plus one High-Level input (the Speakon).

Currently I'm using the Speakon (from the Parasound to the REL) and the LFE (from the Marantz's L and R Subwoofer Preouts to the REL). If I skip the Speakon and go Low-Level, is that the same as Line-Level? Do I need/want LFE inputs while I'm using the Low-Level inputs?

Holy Cow ... I know that I'm lame guys. I sincerely apologize to the entire forum.

Humbled and trying my best to learn about this,
Scott

 

[Wayne A. Pflughaupt]

Gosh Scott, I didn’t mean to make you feel all beat-down! I feel dumb because I don’t get what that speaker-level thing on that sub is all about! It just seems to mainly serve up confusion, and it’s doing a good job of that!

Yes, for all practical purposes LFE and Line In are both line-level inputs. Basically, if it’s an RCA jack it’s line-level, aka low-low level. Speaker connections from an amplifier are considered high-level, or speaker-level.

And sometimes the manufacturers add to the confusion. For instance, most receivers don’t have an output labeled LFE. Typically they are just labeled “subwoofer,” as your Marantz is. However, that “subwoofer” output will be carrying the so-called LFE from movie soundtracks. Now that I think about it, we seem to typically find a jack labeled LFE only on subwoofers.

As far as the REL goes - I don’t know, perhaps the LFE input has no crossover filtering, assuming that the AVR will be doing that. I can’t find a manual for it. Maybe you have one?

To better answer your previous question, there’s no good reason to send signal from both the miniDSP and your Marantz to the sub. If you want the sub equalized via the mini, it should feed the signal to the sub. Adding an unequalized signal from the Marantz can’t be doing anything good. I would HOPE that the sub was designed so that both those inputs would not be active at the same time!

Anyway, hope this helps...

Regards,

 

[ssanford69]

Thank you ... I really do appreciate your help Wayne. Maybe I don't feel so silly for not understanding this clearly. I thought that all these terms/signals had the same functions and were treated the same way by all the speaker and receiver manufaturer. But after looking at the attached REL S Series Subwoofer manual, it seems that they (REL) don't do it the "common" way. I'm going to read it more closely to see if I can understand how this works, but again Wayne/ AV NIRVANA Forum, all your input and guidance is GREATLY appreciated.

 

[JStewart]

I would absolutely love your input about know how to connect my system correctly. I have the Marantz SR7011 AVR running to a Parasound A21+ Power Amp. It drives the PSB Imagine T3 Towers. It also passes a "high level" signal through a set of Speakon cables to dual REL S/3 SHO Subs (these also have low level inputs). I use the sub pre-outs of the SR7011 for the LFE signal to the REL's.

This is exactly the right way to connect the sub per the manual as I suspect you knew. Set the front speakers in the Marantz to Large as stated in your REL manual and set all other speakers to small. Start with the crossover in the Marantz set to 80Hz as recommended by THX. The frequencies below 80Hz (a simplification but close enough for this discussion) will then be routed to the REL through the Marantz LFE output along with the actual LFE channel. The REL will do a better job of producing the low bass than your other speakers and this is referred to as the Marantz processor's bass management system.

Follow the directions in the REL manual to blend the REL with your mains using the REL crossover and hi-level volume control as well as for its placement in the room.

For the record this is a unique way to wire a sub. Some would disagree with its efficacy, but REL is well known and popular product so who knows.

Is there a way to manage the bass and do room correction using the MiniDSP 2x4 while continuing to use the High Level REL connections from the power amp?

Yes and you basically already have it. Connect the LFE out from the Marantz to input 1 of the minidsp. Connect line 1 out from the minidsp to the LFE .1 in on the REL.
Note that with this configuration however there will be no mindsp processing of the mains low frequency signals as the REL is getting the signal for the mains though the hi-level connections. This may or may not be a concern and you will not know what is best until you become familiar with REW and measuring.

To explain the signal terminology simply:

Hi Level is an amplified signal such as that coming form the speaker terminals on your parasound.

Line level is a signal coming from a pre-amp. For example the outputs from the Marantz that connect to the Parasound.

LFE out from the Marantz IS ALSO A LINE LEVEL SIGNAL. Really there is no difference between connecting the Marantz LFE out to the REL line level in OR the REL LFE.1 in EXCEPT that the LFE.1 in on the REL bypasses the line level crossover on the REL which is what you want. Remember you've already set the crossovers in the Marantz bass management system. You don't want a crossover on top of another crossover that's already doing its job correctly.

I should also add that helping each other is a part of this community so ask away when you have a question. Good chance that one of us will know the answer.

 

[ssanford69]

OK ... that helps a lot JStew! Man - I REALLY appreciate the details immensely. Now it's making more sense. The way the REL handles all it's inputs is much clearer and the signals are making more sense. But I'm going to "ask away" because I know that I can understand a lot more.

• Does the Marantz Sub Pre-out send a full range signal; or is it clipped at a certain frequency?
• I know the REL LFE.1-in's crossover is hard-set at 120 Hz. So I just have to make sure that I don't remove any frequencies less than 120 Hz with filters in the DSP ... right?
• Would it make sense to set the crossover on the REL to its max? I understand that we want to take some of the bass load off the mains, but I don't understand where and how to do it through the various crossover settings on the REL, the Marantz and the DSP. I feel like I can let the Marantz and the DSP handle the crossovers, but is that a good idea?
• In the Marantz setup menu under Speakers, the Bass menu has an option called "Subwoofer Mode". It allows for LFE+Main or LFE only. There's also a crossover setting under this menu Labeled "LPF for LFE" ranging from 80 Hz to 250 Hz. I understand the meaning of all the acronyms, but not the functionality of the settings. I'ts confusing when we're setting crossovers in multiple places. There are alos independent Crossover settings in the "Speakers" menu for the Front, Center, and Surround speakers. Plus there's another menu with other duplicate settings in the "2ch Playback" menu (i.e. Front = Small or Large, SW Mode = LFE or LFE+Main, Crossover = 40 Hz-250 Hz, plus distance and level adjustments for the Fronts). I assume the 2ch Playback is only in effect when I'm in stereo mode, but the LFE+Main setting here is confusing, especially when there are crossover settings under the "Bass" menu AND and the "Crossovers" menu. There's a lot of questions in there - but not a single question mark. Hopefully there's any easy explanation about the different settings, their functionality, and when/why they do or don't counteract one another?

OK ... that's a major regurgitation on my part. I can only pray that someone is in the mood to compose the novel that will likely be the "whole story"!

Thanks again JStew,
Scott

 

[JStewart]

Whew. Be careful what you ask for!

If you are at all unsure of the BASS MANAGEMENT purpose and function check out this brief article https://www.audioholics.com/subwoofer-setup/bass-management-basics-2013-settings-made-simple

Next, we've established that REL has different thoughts about how to connect a sub to the Mains (the right and left front speakers).and how that wiring is done.

Does the Marantz Sub Pre-out send a full range signal; or is it clipped at a certain frequency?

It sends the signal from the movies "low frequency effects" channel PLUS the signal below the crossover you have set for all the other channels you have designated as SMALL.
In the Marantz there is a setting LPF FOR LFE. 1) it only applies to the LFE Effects Channel track on the disc/stream your playing. 2) It does NOT affect the bass below the crossover for any channel marked as small. 3) There should only be LFE below 120Hz anyway as recorded by the artists. I've never understood a purpose for the settings existence although I'm sure must be one. Set it at 250Hz and forget about it.

I know the REL LFE.1-in's crossover is hard-set at 120 Hz. So I just have to make sure that I don't remove any frequencies less than 120 Hz with filters in the DSP ... right?

The crossover control on the REL should NOT have any effect on the .1/LFE input. It's an LFE input. Its already being fed what you want to have fed to it. REL knows this. That's why they put it there. Also explained in my first post.

Would it make sense to set the crossover on the REL to its max? I understand that we want to take some of the bass load off the mains, but I don't understand where and how to do it through the various crossover settings on the REL, the Marantz and the DSP. I feel like I can let the Marantz and the DSP handle the crossovers, but is that a good idea?

The crossover on the REL is there to blend the output form the HI-Level from/for the fronts to the low output capability of the Mains. Or look in the PSB owners manual and find the -3db point they likely provide for the low frequency output. Set the XO on the REL to that number as a starting point. IIRC there is a procedure in the REL manual to facilitate this blending.
.

In the Marantz setup menu under Speakers, the Bass menu has an option called "Subwoofer Mode". It allows for LFE+Main or LFE only. There's also a crossover setting under this menu Labeled "LPF for LFE" ranging from 80 Hz to 250 Hz. I understand the meaning of all the acronyms, but not the functionality of the settings. I'ts confusing when we're setting crossovers in multiple places. There are alos independent Crossover settings in the "Speakers" menu for the Front, Center, and Surround speakers. Plus there's another menu with other duplicate settings in the "2ch Playback" menu (i.e. Front = Small or Large, SW Mode = LFE or LFE+Main, Crossover = 40 Hz-250 Hz, plus distance and level adjustments for the Fronts). I assume the 2ch Playback is only in effect when I'm in stereo mode, but the LFE+Main setting here is confusing, especially when there are crossover settings under the "Bass" menu AND and the "Crossovers" menu. There's a lot of questions in there - but not a single question mark. Hopefully there's any easy explanation about the different settings, their functionality, and when/why they do or don't counteract one another?

Lots of questions.

Set it for LFE only. Everywhere you find it. LFE + Main duplicates the LFE on the main channels too. There may be reasons to do this. For your set up (and most any other) it will be detrimental.

LPF for LFE already explained earlier this post.

Not knowing what all your speakers are I'll stick with the generic THX recommendation to for any speaker designated as small set the XO to 80. Who am I to argue with THX?

Yup. Marantz gives you a lot of options that some may use for some obscure or just preferential reasons. Start by thinking the Artist wanted you to hear their work a certain way. They mixed the sound already to the speaker they want it to go to. Why would we want to change it. I wouldn't go to a museum and look at paintings with blue lens eyewhere on. Not what the artist intended.

Bass Management is a recognition that the artist may have wanted to play a sound in your center channel that is to low for your center channel to re-produce. Bass below 80hz is omni-directional and most normal humans can't tell where its coming from. The artist wanted us to hear it => center channel can't do it => send it to the subwoofer then, it can do it. => sounds right to us, we can't detect where it came from anyway.

 

[JStewart]

@Wayne A. Pflughaupt
A like from someone with your credentials is an honor. Thanks!

 

[ssanford69]

Thanks JStew - I think you responded in less time than it took me to write all the questions. This is soooooo VERY cool to get so much useful and understandable information! Here is what I found on the PSB Frequency Response Specs Page. Should I set the REL XO as low as 24 Hz? I guess that's the starting point, then I adjust it based on the REL "How To" videos on this page

How To Tune Videos (ALL)

How to tune my subwoofer using the High or Low Level inputs How to tune a Stereo Pair of Rels How to tune my subwoofer for Home Theater What is the LFE input...

www.youtube.com

Frequency Response
On Axis @ 0° ±3dB 24-23,000Hz
On Axis @ 0° ±1 1/2dB 30-20,000Hz
Off Axis @ 30° ±1 1/2dB 30-10,000Hz
LF Cutoff -10dB 20Hz

I've got a much better understanding of how to connect and set things up. Once I've positioned everything properly, I will probably follow up with another thread about taking measurements with REW, calibrating and doing room correction with the miniDSP. Before I start all that, can I get some directions regarding the order of operations? I'm curious about the order I should perform all the taks that I've been learning about. To that end, I've got REW, the Dayton Audio UMM-6 USB Mic, and the miniDSP 2x4 HD, and an SPL meter at the ready. I've hooked it all up and done some random measurements just to see if I could make it work - and I did. Now I think that I need to understand how to proceed from here. These are the tasks that I need to perform, but I'm very unsure about the order, and I'm even more ignorant about the things that I'm missing. So a general outline of the proper steps would be very helpful.

• Positioning the speakers and subs. I know about the bass crawl for the subs but I'm wondering if there is a better way to find the best room position by taking measurements vs. listening and moving stuff around?
• Gain Matching the subs and speakers? Is this as simple as taking setting the Volume on my Marantz and adjusting the gain on the AVR, the REL's and/or the DSP?
• Phase Matching? This is not clear to me. I understand the phase switch on the REL's (0 or 180 Degrees). It seems like listening to the difference is pretty simple, but I know that there's a lot more to this and I would love some general guidance.
• Running Audyssey on the Marantz (I also have the MultiEQ app). Is this something that I need/want to do? I understand that I need to time align all the speakers, but again, I'm REALLY behind the curve on this concept. So general guidance can get me started in my understanding and the order that I should perform all of these tasks.
• Should I take Measurements using REW and make adjustments? Should I run Audysses before, during, after, or not at all? Should I jump right into Dirac Live? Or is there some combo that makes the most sense?

Again, for the moment I'm looking for general guidance on the order of all these tasks along with practical guidance as to whether or not I should be using all these tools and/or if I should use any/all of them together, separate, or piecemeal. Once I understand the order I will do my best to research, learn and perform trials before I hammer the forum with more and more questions.


With my humble gratitude,
Scott

 

[JStewart]

Positioning the speakers and subs. I know about the bass crawl for the subs but I'm wondering if there is a better way to find the best room position by taking measurements vs. listening and moving stuff around?

This definitely Step 1.
For REL the positioning is suggested in a front corner. REL's idea is to keep it near the mains. I would agree with this as a start and only move it from their if you get bad measurements with REW. Do you have additional subs? If so then I would use REW with one of two methods to accomplish the positioning. Each works equally well. Use whichever is easier.
1. position the mic at the main listening position (MLP) and position the sub in the location you want to test. Run a REW frequency sweep. Repeat for any other position you want to check.
2. Put the sub in the MLP. Put the microphone where the sub will be. Run a REW sweep. Move the mic to the next position you want to check.

Gain Matching the subs and speakers? Is this as simple as taking setting the Volume on my Marantz and adjusting the gain on the AVR, the REL's and/or the DSP?

Step 2
We are talking about the LFE here right? Because you will follow the instructions in the REL manual to match the REL to the mains.
For the LFE I would volume match all the subs. You can do that be using the Marantz test signal for the LFE channel and an SPL meter. With the SPL meter at the MLP you will set the volume control on each sub so the SPL is the same at the MLP. The question is what to set it for and this will vary with the number of subs. Start by sending the Marantz test signal to the left or right speaker and getting a reading. You want set the volume on each sub so 1) they are the same and 2) the combined response is within a dB or 2 of the main you tested. The result will be the combined SPL of all the subs together will equal the SPL (volume) of one of the mains. There may be some fine tuning later that Audy does or you do manually later and that's OK.

Phase Matching? This is not clear to me. I understand the phase switch on the REL's (0 or 180 Degrees). It seems like listening to the difference is pretty simple, but I know that there's a lot more to this and I would love some general guidance.

Step 3
Phase matching, for purposes of this exercise, is equivalent to setting the distances. As a start let Audy set it for the LFE channel on the marantz for the Sub group (again assuming you have more than 1). The phase adjustment dial on the REL does nothing for its.1/LFE connection. It will be used to match the distance of the REL to your mains. The REL manual should have some guidance on this. I would start there. How well it works can be checked after with REW when you get there. REW can also be used to check how well Audy has done with the LFE distance setting. But it should be fairly reliable from the start. Most often its just a tweak for better alignment of subs to mains for music and this will not apply here because your mains are not using the LFE channel to augment bass. The REL hi-level connection is handling this.

Running Audyssey on the Marantz (I also have the MultiEQ app). Is this something that I need/want to do? I understand that I need to time align all the speakers, but again, I'm REALLY behind the curve on this concept. So general guidance can get me started in my understanding and the order that I should perform all of these tasks.

Step 4
Yes run Audy. It will do a good job setting the distances and relative volumes in the Marantz. You can check with measuring tape or laser after for distance correctness and with the Marantz test tones and SPL meter for volume afterward to double check it if you wish. Then in the Marantz you can listen to the system without the Audy room correction (frequency response adjustments) engaged, if you want to. Audy may do a good job for you. Listen and decide for the moment which is best. Either way, the distance and volume settings will remain intact in the Marantz after Audy unless you manually change them.

Should I take Measurements using REW and make adjustments? Should I run Audysses before, during, after, or not at all? Should I jump right into Dirac Live? Or is there some combo that makes the most sense?

I think this is basically answered above except for the Dirac Live. If you were to get Dirac Live, how would you intend to use it with the Marantz? Anyway, I'd personally save that decision for later and start by getting things set up the way they should be and if there was a deficiency go from there.

Regarding the REL crossover setting. Your PSBs are -3dB at 24Hz so 24 or 25Hz will be your starting point on the REL crossover dial. Nice speaks by the way.

A quick summary here... everything we've discussed is to get things set up the way they should be according to the REL manual for the REL and standard procedures for the rest. After its done take a minute to use and enjoy the system. When your ready you can start testing and fine tuning with REW and/or the MiniDSP.

 

[Wayne A. Pflughaupt]

@Wayne A. Pflughaupt
A like from someone with your credentials is an honor. Thanks!

Ha! If my credentials were all that, you wouldn’t have needed to post on this thread! Thanks for jumping in and saving the day.

Regards,
Wayne

 

[ssanford69]

Much appreciation to both Wayne and JStewart! You guys are awesome. I'm sure that I'll be back soon with more inquiries, but you've got me started - plenty to do for now!