Question: High Level vs unbalanced RCA input on Subwoofers?

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Joey_V wrote: »

I am using Cary SLP05 which does not have bass mgmt, essentially I would be using one of the unused outputs from the pre into the subwoofer.

Or go hi level and hook it from the speaker terminal end or the amp section.

Looking at JL Gotham or Rel 25.

I played with high (speaker) level and low (rca) level connections on my 2 channel sub. High level always sounded a bit better, so that's what I use. Velodyne, REL and Rythmik still come with high level, but unfortunately most don't.

This is one bad a$$ sub that should be on your list. http://velodyneacoustics.com/subwoofers/digital-drive-plus-18.html

I’m not exaggerating when I say I spent at least 30 hours integrating my JL into my two channel system using interconnects from my preamp. I followed the Sub Set up recommendations on RELs website and I was able to dial the sub seemless into my system using high level inputs from the amp. I run my JL from the 4 ohm binding posts on my tube amp. I built special cables using military surplus twisted, shielded silver wire, with furutech gold spades, soldered with silver solder. I run my mains full range with the little monster JL, cross over set at 40ish HZ.

For the best blend high level is king. But I guess fancy DSPs built into subs these days correct for that.

Joey_V wrote: »

WLD and Mikey - I would probably rather get the Gotham use it singly and then save up for a 2nd.
It is the Rel No 25. I could start with 1 then bridge out to 2 later on.

Man, I guess you are set at dropping some serious coin on JL , Rel or two.

Yeah, the idea of clean output from a DIY 24" sub is a bit of a stretch for some in the 2 ch crowd. However, there are some REALLY good subs out there. One can get 2-3 Rythmik F18's for the price of a single No. 25 or 4-5 for the cost of a single Gotham.

The F18 is AWESOME! They are touting lower distortion and equal or more output than the DD18+! ($1850 in Piano black)
http://www.rythmikaudio.com/F18.html

Test & Measurements
https://data-bass.com/data?page=system&id=145

Rythmik Audio wrote:

The independent test lab site www.data-bass.com has published the max distortion numbers for F18. The F18 has lower distortion and yet more output than Velodyne DD18+ for 1/3 of the price. In addition, the test results also include the impulse response of 18hz high damping which shows minimal ringing, a testament of F18 articulation bass sound.

And in a Dirac Live unit for room correction - https://www.minidsp.com/products/dirac-series/ddrc-24

The Rythmik is a solid suggestion. The reason I like the Velodyne is the front display and remote control capability, which I've found useful.

Dan, you and I don't agree on much, but you nailed that one!

mantis wrote: »

I can clear the dust here which is easy to do IF you actually have experience setting up subwoofer in different rooms.
As you mentioned a subwoofer is an integration into ones living space. It pressurizes the space to recreate bass. The issue usually one doesn't have the proper amount of space to complete lower frequencies. So what you end up with is delayed signals which slap you after they bounce around in the room or intill completion of the wave.

Without experiencing this yourself, this is all nonsense I'm babbling to the untrained.

Everyone here has their own experiences. Mine starting with actually playing music and then later the pursuit of stereophonic sound with much trial and error along the way. No I never worked in or owned an audio store or owned a $50K-$100K stereo system. However, I've ALWAYS loved music and have an ear for good sound.

As a kid in the 70's-80's I learned about room interaction and response trying to get my bass drum to sound good in different spaces. Later years I learned even more about acoustics playing in different types of bands in all types of venues. Setting up instruments and adjusting PA systems, etc. There's low frequency content coming from live instruments rather it be an acoustic jazz trio or a large orchestra. I've played in bedroom sized rooms as well as 100,000 seat stadiums.

Later years Tom Nousaine, and others taught me a little something about subwoofers. While Richard Clark and David Navone taught me a little bit about speaker level inputs driving amps. My first subwoofers for my car and 2 ch home system were raw sub drivers I ordered from Madisound. In both scenarios the subs were connected using passive crossovers driven by the same amp driving the main speakers. In my car I had a three-way system with two subs, two mids, and to tweeters using custom passive components driven by a single amp.

The Lucio Proni / JL Audio SQ Ford Mustang was the inspiration:

http://www.caraudiojunkies.com/showthread.php?1254-Lucio-Proni-1987-Mustang-GT-1990-CSR

I've ALWAYS been a DIY'er, tinkerer that likes to experiment and do things with my hands. I've learned that I preferred a dry low Q type of sub bass sound that does not bring attention to the sub or its location. I didn't start using preamp inputs to feed a sub until I put together a home theater system. I've even been asked before by an auto engineer friend to lend my ears and expertise on an OEM sub integration truck project he was working on.

It makes sense for someone with a high end full range system like Joey to consider speaker level inputs to drive his subs. He has very resolving equipment and is more likely to pick up on the benefits. However, given the wide range of preamps, amplifiers out there its very possible that there are preamp driven subs that can sound good and resolving. Unless one has done an A-B test of the Rel No. 25 vs. the Gotham connected to his system comparing both line level and speaker level inputs how can one really know the outcome? Everyone's experiences vary and some have not been able to hear a difference between the two.

Using this same "purist" logic the ultimate matched signal setup would to use identical amps / Amp manufacture for both the mains and sub fed by preamp signals. Mate this with an ultimate low distortion mechanical marvel like that 24" monster that I posted. However, many steer clear of subs all together or they opt for options like the REL, and JL. Why is that? Are the "purist" really getting their money's worth going this route?

There are always compromises in this hobby. There is no one empirical path to the audio holly grail that is going to work for everyone. So, respect the path of others and stay humble and enjoy the music because that's what its all about!

F1nut wrote: »

Joey_V wrote: »

I am using Cary SLP05 which does not have bass mgmt, essentially I would be using one of the unused outputs from the pre into the subwoofer.

Or go hi level and hook it from the speaker terminal end or the amp section.

Looking at JL Gotham or Rel 25.

This is one bad a$$ sub that should be on your list. http://velodyneacoustics.com/subwoofers/digital-drive-plus-18.html

I whole-heartedly agree with this recommendation. I am now the fortunate owner of two (2) DD18 subs and a DD12. The servo control and GUI allow for infinite adjustment and flexibility of every aspect of the sub, including an 8 band parametric eq. The supplied microphone and RTA program show exactly what affect your adjustments are having.

I have been spoiled to the point that I would not consider a sub that did not incorporate servo control - I feel it truly indispensable in a quality sub, especially for 2ch music.

Just my .02

Prob on the bottom here with the catfish but I recently hooked up the SVS with XLR’s and love the stereo integration it offered. The +6db was easy to balance and using HT bypass I lost the pure LFE but I don’t regret for the 2.1 listening.