Highlevel subwoofer connection

shektau6 · « **on:** 17 Feb 2019, 04:03 pm »

Just wondering for Nuprime class D amp, do one need to follow the below instruction if connecting subwoofer using high level output?

https://relsupport.zendesk.com/hc/en-us/articles/115004486607-Class-D-Amp-Connection-Methods

Thanks!

mick wolfe · « **Reply #1 on:** 17 Feb 2019, 04:54 pm »

Can I assume this applies to any subwoofer/class d amp relationship? I've always hooked my HSU subs high level in a conventional manner with my Classdaudio amp. Maybe disaster awaits

Thx for posting this.

mick wolfe · « **Reply #2 on:** 17 Feb 2019, 08:06 pm »

Just a quick followup....at least in my case. First off, my HSU subs have no grounding lug either at the end of their power cord or the IEC recepticle at their plate amp. The only way for the sub to function speaker level is for both + and - binding posts of the amp connected. According to Tom at Classdaudio in regard to his amps and the HSU subs......"hook them up speaker level like you would any other amp". This is what I've done for years with no issue. Now with this all said, best to contact Nuprime and your subwoofer manufacturer (if isn't REL) in regard to the REL link.

rustydoglim · « **Reply #3 on:** 18 Feb 2019, 02:37 pm »

https://nuprimeaudio.com/ufaqs/can-the-amplifiers-speaker-terminals-be-used-as-source-inputs-e-g-to-rel-subwoofer/

But REL said that their sub now have no problem with class D amps.

Phil A · « **Reply #4 on:** 18 Feb 2019, 03:08 pm »

I use two Rel Storm III subs with my class D amp - no issues - just have it connected via the postive inputs of the amp.

MttBsh · « **Reply #5 on:** 18 Feb 2019, 04:50 pm »

Quote from: Phil A on 18 Feb 2019, 03:08 pm

I use two Rel Storm III subs with my class D amp - no issues - just have it connected via the postive inputs of the amp.

I’ve always had my two subs hooked up to an audio out from my preamp. I use a class D amp - is there any advantage to your method of hooking your subs up to the positive inputs of your amp (maybe because you don’t use a preamp?)

shektau6 · « **Reply #6 on:** 19 Feb 2019, 06:29 am »

Quote from: rustydoglim on 18 Feb 2019, 02:37 pm

https://nuprimeaudio.com/ufaqs/can-the-amplifiers-speaker-terminals-be-used-as-source-inputs-e-g-to-rel-subwoofer/

But REL said that their sub now have no problem with class D amps.

Thx Jason for posting the link above. I am using IDA-8 so I will need to use the method as described in REL website. I planned to get the REL sub and according to their advice speaker level output will achieve the best sounding result. I also use the sub in separate HT setup and that will give me more flexibility as well.

MttBsh · « **Reply #7 on:** 19 Feb 2019, 04:36 pm »

I've never experienced any problem connecting my subs to an audio out from my preamp, but it makes sense that by connecting them to the speaker terminals of my amp (Highlevel subwoofer connection) the subs are receiving the improved signal generated by my amp - the same signal that's sent to my speakers - instead of from my preamp. This just means two sets of wires (speakers and subs) connected to the amp's speaker terminals.

rustydoglim · « **Reply #8 on:** 21 Feb 2019, 08:36 am »

Our advice is that the sub should get signal from preamp.
Please, how can the amp "improve" the signal from the preamp or source? I think we know a thing or two about amp design.
The amp amplifies the signal and the noise too. And you want to feed that to your sub?
What's a sub? It is just a low pass filter with amp and speaker.

Phil A · « **Reply #9 on:** 21 Feb 2019, 12:44 pm »

Quote from: MttBsh on 18 Feb 2019, 04:50 pm

I’ve always had my two subs hooked up to an audio out from my preamp. I use a class D amp - is there any advantage to your method of hooking your subs up to the positive inputs of your amp (maybe because you don’t use a preamp?)

That's the recommended set-up for Rel (and I have 4 Rels, which at the present are used in 3 systems, and have them 15+ years). Yes I use a preamp (most of my systems are listed). Rels have two sets of inputs (high and low level) with separate volume controls and a crossover for the high level input. So that in my main system, which is an integrated AV system, I have the LFE output from the receiver going into the subwoofer as well and the crossover is determined in the receiver for movies. I have one two channel system with a Rel Strata III and it is connected to both the positive and negative amp terminals as it is a Class AB amp (Hegel 190 Integrated). The theory behind it is that the high level input steals a bit of signal (and it's more like an interconnect vs. a speaker lead) from the amp and gets a similar sonic quality of the amp. Many moons ago I also had a Dahlquist sub with the Dahlquist electronic crossover. There are many ways of doing things and it's a matter of what equipment one uses and their preferences.

MttBsh · « **Reply #10 on:** 21 Feb 2019, 03:49 pm »

Thank you Phil for your explanation

And Rusty:

Quote from: rustydoglim on 21 Feb 2019, 08:36 am

Our advice is that the sub should get signal from preamp.
Please, how can the amp "improve" the signal from the preamp or source? I think we know a thing or two about amp design.
The amp amplifies the signal and the noise too. And you want to feed that to your sub?
What's a sub? It is just a low pass filter with amp and speaker.

I had read several articles describing advantages of connecting subs to amps instead of preamps, here's a quote from PS Audio:
"each power amplifier has its own sonic signature. If you use the amp’s output (rather than the preamp's) to feed the sub amp, you maintain sonic consistency and improve system synergy."
As you state, you know a thing or two about amp design, probably a lot more than PS Audio and certainly a lot more than I do, so I will keep my subs connected to my preamp.

Phil A · « **Reply #11 on:** 21 Feb 2019, 03:59 pm »

I should add that while I've had my main system Rel Storm IIIs connected by both the high and low level inputs, I currently only use them for music via the high level input. I have a Power Sound Audio HT subwoofer (which of course is made to put out more output). In a 2-channel system, I use the Rel Strata III via the high level only and then I have a Rel Q150 in another system which is connected by both the high and low level inputs. I don't use that system tons for music as it's basically my 4k HT system.

witchdoctor · « **Reply #12 on:** 21 Feb 2019, 05:10 pm »

Quote from: Phil A on 21 Feb 2019, 03:59 pm

I should add that while I've had my main system Rel Storm IIIs connected by both the high and low level inputs, I currently only use them for music via the high level input. I have a Power Sound Audio HT subwoofer (which of course is made to put out more output). In a 2-channel system, I use the Rel Strata III via the high level only and then I have a Rel Q150 in another system which is connected by both the high and low level inputs. I don't use that system tons for music as it's basically my 4k HT system.

Hey Phil, have you considered connecting your various systems through your network or have you already done it?

Phil A · « **Reply #13 on:** 21 Feb 2019, 06:01 pm »

Quote from: witchdoctor on 21 Feb 2019, 05:10 pm

Hey Phil, have you considered connecting your various systems through your network or have you already done it?

I have all my music on an NAS (Synology - RAID 1) with Minimserver. I have a Lumin U1 in the main sytem which uses the same library. I already had JRiver for Windows for a long time. My main (Windows 10) PC as does the old Windows 7 one in the bedroom. I have two fanless Windows 10 (started as Windows 8 ) PC music servers, one of which I used in the main system prior to getting the Lumin U1. So I have JRiver on those now in secondary systems and they all use the same library on the NAS. Before getting the Lumin (and NAS), I used local hard drives with my Windows music servers and now they are for back-up duty.

One secondary system has a Hegel H190 Integrated Amp/DAC/DLNA streamer and I initially used it via ethernet with the Bubble UPNP App. The USB in the Hegel (it is their $4k list entry level) is very limited. I could change the settings on my main PC (or one of the music servers) and use it via DLNA, however doing that I can't adjust the sampling frequencies (similar problem with the Bubble UPNP App as it dumbed by DSD files down to something that didn't sound good and had dropouts). The Hegel will do up to 192kHz via coax so the simple solution was to buy a Wyred4Sound USB to coax converter on close-out and now I just use JRiver with the little PC to convert DSD to 176.4 and PCM files greater than 192. I only use the secondary systems on a limited basis (my main back-up system is used 10-12 times/year) but I like having different speakers technologies (the back-up system uses Ohm Microwalsh talls). If I upgrade something, I'll rotate it to a secondary system and if not sell it if it is worth selling or give it away if it is not.

shektau6 · « **Reply #14 on:** 6 Mar 2019, 01:34 pm »

I just bought the REL T5i and what a surprise to find out I got no sound using the supplied Neutrik Speakon high level input to my IDA-8 int amp. I followed REL advice to float the ground wire. I also checked the Neutrik connector with a multimeter and confirmed the wiring is all fine. Not sure if it's because the Nuprime and REL are not compatible or my subwoofer is faulty? if I connect via sub-out which works fine but it seems to defeat the main advantage of using the REL....I can't imagine bringing the 30 lbs sub back for servicing though...sigh. Has anyone has problem using REL high level connection with IDA-8 ? (I have also tried to connect the ground wire using conventional method and that doesn't work as well)

Phil A · « **Reply #15 on:** 6 Mar 2019, 02:06 pm »

Quote from: shektau6 on 6 Mar 2019, 01:34 pm

I just bought the REL T5i and what a surprise to find out I got no sound using the supplied Neutrik Speakon high level input to my IDA-8 int amp. I followed REL advice to float the ground wire. I also checked the Neutrik connector with a multimeter and confirmed the wiring is all fine. Not sure if it's because the Nuprime and REL are not compatible or my subwoofer is faulty? if I connect via sub-out which works fine but it seems to defeat the main advantage of using the REL....I can't imagine bringing the 30 lbs sub back for servicing though...sigh. Has anyone has problem using REL high level connection with IDA-8 ? (I have also tried to connect the ground wire using conventional method and that doesn't work as well)

That's surprising (I'd guess your Rel has two RCA inputs, one for LFE and one for a preamp out?). I don't use a sub with my IDA-8 on my desktop system with big bookshelves (pic below) but I have a spare system (among several) that is in my upstairs bonus room (basically a guest bedroom), while not used often, had a Sunfire, Jr. sub that needs repair. I got a deal on a Rel T5 copy (a Sumiko, which used to distribute Rel, S.5 - wanted the model above it as the room is big but got in too late). I had the system apart (took the Teac UD-501 DAC over to someone's house to let them hear it) and got my Sumiko S.5 about 1PM yesterday. Had to do stuff in the afternoon and brought it upstairs and went into my garage bin for upgrade Speakon cables I've made but all I had in there was ones for use with two Rel subs (wired in mono). So I made one last night and probably sometime this weekend will get to setting it up for music and HT. Remember that for class D, Rel has recommendations that only the positive inputs to the amp are connected.

Desktop speakers (why I don't use a sub with my IDA-8)

shektau6 · « **Reply #16 on:** 6 Mar 2019, 02:30 pm »

Quote from: Phil A on 6 Mar 2019, 02:06 pm

That's surprising (I'd guess your Rel has two RCA inputs, one for LFE and one for a preamp out?). I don't use a sub with my IDA-8 on my desktop system with big bookshelves (pic below) but I have a spare system (among several) that is in my upstairs bonus room (basically a guest bedroom), while not used often, had a Sunfire, Jr. sub that needs repair. I got a deal on a Rel T5 copy (a Sumiko, which used to distribute Rel, S.5 - wanted the model above it as the room is big but got in too late). I had the system apart (took the Teac UD-501 DAC over to someone's house to let them hear it) and got my Sumiko S.5 about 1PM yesterday. Had to do stuff in the afternoon and brought it upstairs and went into my garage bin for upgrade Speakon cables I've made but all I had in there was ones for use with two Rel subs (wired in mono). So I made one last night and probably sometime this weekend will get to setting it up for music and HT. Remember that for class D, Rel has recommendations that only the positive inputs to the amp are connected.

Desktop speakers (why I don't use a sub with my IDA-8)

My T5i has 2 RCA inputs and I did follow Rel recommendation to connect to the 2 positive output on the amp and leave the ground wire floats. I think i am just got unlucky getting a faulty Rel subs...

kaka89 · « **Reply #17 on:** 7 Mar 2019, 09:15 am »

I have REL T Zero connected to my ST-10 and it works perfectly.

Try turn the REL's high level cable plug, it has a locking mechanism.

shektau6 · « **Reply #18 on:** 7 Mar 2019, 12:25 pm »

Quote from: kaka89 on 7 Mar 2019, 09:15 am

I have REL T Zero connected to my ST-10 and it works perfectly.

Try turn the REL's high level cable plug, it has a locking mechanism.

Thx Kaka, the connector is turned and locked correctly. Can I ask which connection method you choose? Did you float the ground wire as suggested by REL?

kaka89 · « **Reply #19 on:** 7 Mar 2019, 03:40 pm »

The black (ground) wire is connecting to ST-10's ground output. ST-10 has it in the back panel. Not sure does the other models has it.