Connecting a subwoofer to an active Linn system

[foxwelljsly]

Can anyone advise the best way to connect a subwoofer up to a Linn active system comprising an (non-DA) Exotik pre-amp, a 5125 power amp and a pair of katans?

My sub is not a Linn sub, but it does have mono phono, stereo phono and neutrik connections.

I'd rather not use the sub out from the Exotik as enabling it removes everything under about 100hz from the pre-out signal and I really only want the sub to fill out below the 60-70hz range where the katans roll off.

cheers

 

[linnfomaniac83]

Can anyone advise the best way to connect a subwoofer up to a Linn active system comprising an (non-DA) Exotik pre-amp, a 5125 power amp and a pair of katans?

My sub is not a Linn sub, but it does have mono phono, stereo phono and neutrik connections.

I'd rather not use the sub out from the Exotik as enabling it removes everything under about 100hz from the pre-out signal and I really only want the sub to fill out below the 60-70hz range where the katans roll off.

cheers

It’ll work just fine from the regular pre-out, the sub should have all the filtering needed to integrate it nickels into your system.

 

[cjyosemite]

I am not familiar with your kit but on a general note of getting the cross-over right I have never been happy whenever I have tried to use a sub on a system with HiFi speakers until earlier this year when I bought a pair of ProAc tablet anniversary speakers, a quite small stand mounter with a good amount of bass for their size but not the real deep bass from organ. I have a Castle Classic sub (ATC design) which only has a pair of phono inputs so no choice of connectivity method which was possibly an advantage as there were fewer options to try out. Firstly I played the music without the sub to get an overall idea of the ProAc's capability. Then I played it again with only the sub with maximum crossover point & sound level to get a feel of the frequency range of the sub & relative volume levels compared with the ProAcs & was a bit surprised by how much crossover there was. I was then a case of gradually lowering the crossover level & sound level on the sub until I got to the point where there was very little crossover. It was only at that stage that I played the music through the ProAcs & the sub together, followed by a bit of rechecking with ProAcs only & then with sub only with a bit more fine-tuning. Previously I had always followed the recommended method of playing through both together but never satisfied that I had it right for different recordings. Now I am happy that it is right & never been tempted to make further changes & have been a bit surprised by how little is required from the sub with only the really deep stuff not there from the ProAcs.

I do not really understand why using the pre-outs on your amp cuts off below 100 Hz but if that is the case you really only have the option of using the neutrik connections.

 

[foxwelljsly]

Thanks all. I have figured this out. For info (LM look away now), the Exotik is an analogue only surround pre that most configure to use as a stereo pre. It only has one set of stereo pre outs, so a sub HAS to be connected via the sub out or using the high output neutrik leads to the speaker outs on the power amp.

When you enable the sub channel on an analogue Exotik, it routes all frequencies below 100hz to the sub channel, there is no way of changing this. On the later digital versions of this pre amp, the Exotik DA and the first Akurate Kontrol (Both actually identical) you can set the sub crossover point at many different frequencies. I had planned to upgrade the Exotik to an Exotik DA or Akurate Kontrol to reduce box count and get a better DAC, so this is yet another reason to do so.

 

[linnfomaniac83]

Could you not daisychain from the power amp to the sub? I’m pretty certain you can on a 5125 with active card installed and you definitely can with LK140s. Failings that, you can use a pair of RCA Y splitters.

 

[foxwelljsly]

Could you not daisychain from the power amp to the sub? I’m pretty certain you can on a 5125 with active card installed and you definitely can with LK140s. Failings that, you can use a pair of RCA Y splitters.

I won't have Y adapters anywhere near my stereo, but, yeah, I could connect it to the line outs from the bass channels or the connect the Neutrik cable to the bass speaker terminals, but I wanted a digital pre and such a device properly supports this functionality I'm looking for, which makes me happier than using a workaround.

This was very much a speculative query as I'm only running passive at the moment and, having now used the Katans in my room for a few days, I'm wondering how much I will need the sub, TBH.

 

[linnfomaniac83]

Nothing wrong with Y adapters if you use quality parts but you should be able to daisychain in the short term anyway. Of course the Akurate Kontrol has all the flexibility you need.

 

[foxwelljsly]

OK, if anyone comes back to look at this thread:

Even if your Linn Pre has a sub out, I have found that it’s best to use the high level connection to the bass channels on the power amp. reason being that Linn Katans don’t roll off perfectly in line with the preset crossover points in the pre (60 or 80hz) - in fact they seem capable of going quite a bit lower, so it’s best to let the full signal go to the speakers and set the crossover point manually (in my case to 55hz) and tweak with gain and phase on the sub.

Note, this may not apply if you’re using a matched Linn sub, which, I understand, has some kind of proprietary DSP.

 

[DNM]

Don't Katans have reflex ports? If so, the ports are probably tuned close to 55hz so if you crossover there, your sub will be out of relative phase below the tuning freq. If you invert the sub, it will be in relative phase below the port tuning freq but out of relative phase above the tuning freq.

You could try inverting the sub 180deg and set the Xover at approx. 40hz then slowly adjust upwards to around 45hz.

or

Bung the ports and start at say 80hz working up to 85hz, although with one sub in mono the sub may be localisable if you crossover too high.

If you haven't got a measuring mic, I'd strongly advise getting one. It will save you a great deal of time and hassle. Measure the speakers, with and without high pass filter, close up and at the listening position. Do the same with the sub. Then you'll know exactly what you're dealing with and can then attempt to find the best compromise through a combination of measuring and listening.