Set-up with two subs and an integrated amp

REL subs use the SPKON connection which utilizes your amps outputs. No RCA sub-out needed.

Unfortunately there is no good solution if there are no line level outputs. You are left only with subs that have speaker level inputs which leaves you without a high pass filter a situation totally unacceptable. I would wait on subs until you have the appropriate electronics.  

+1 on the REL solution. REL integrates perfectly with the SPKON conection. If you get a preamp with an RCA sub-out later, REL can do that too. Wireless optional.

What ever you buy you need speaker high level inputs.

The REL has a high level input.  From your integrated speakers output, to the high level REL inputs via a SpeakOn cable with one end bare. The bare wire goes to you speaker terminals on the amp, as per instructions, Red right, positive, Yellow left, positive, black left or right Negative. 

Then out of your bass bins, high level outputs to you speakers, binding post..

Happy hunting

Regards

Another vote for REL. Through High Level Input, the sub integration with your main speakers is straight forward and seamless. There are plenty of YouTube video from REL on the high level connectivity.  

https://rel.net/tube-not-tube/

This is what you need:

https://www.crutchfield.com/S-BZsGXIya5Pj/p_543ADP12/Russound-ADP-1-2-Speaker-level-to-Line-level-Ad...

All you need is what we call a Line Out Converter or LOC. A simple circuit comprised of 2 resistors drops your Line Magnetic speaker level output to line level. In case you’re interested here is the best circuit diagram and electrical explanation on the internet.https://www.epanorama.net/circuits/speaker_to_line.html


Option 1, total cost $2, mod your amp to convert an unused line in into pre-out: scroll through the pictures until you get to the one showing the resistors inside the amp https://systems.audiogon.com/systems/8367 This is a picture of the actual mod. What this does is convert already existing RCA inputs that I did not need into a pre-amp out that I did need for my subs. Here you will see the same two resistors per channel indicated in the epanorama circuit diagram. This mod takes less than an hour all-in.

Option 2, total cost $20, but a LOC from Parts-Express. These are cheesy looking which is why I did my mod. You can pay a lot for an LOC but all you are getting is cosmetic, as inside they are all just the same two cheap resistors.

Option 3, same as Option 1 except you put the resistors inside the sub. If you search around for sub plate amp circuit diagrams you will find they all use this exact same circuit, two resistors, same cheap quality and everything.

Sorry for all the misleading advice. I got the same bad advice asking the exact same question a year ago. I did the research, found the answers, and did the mod. You can do it too. Then please share good information and not be telling people to spend thousands when $20 will do just fine.

rbach +1
I have 2 REL subs and connect them via a 'speakon' high level input from my amps speaker terminals. I found this connection is by far the best way to connect a sub.  

OP:

I have a Line Magnetics LM-508ia and there are no line/sub outs. Can anyone help me out with possible solutions?

rbach:

I think the OP received great advice, REL has the perfect solution for the OP's problem.  mattmiller, wlutke, oldhvymec and lalitk all gave great advice...you are the one giving misleading advice.

Actually no, you must not be reading, because some of that advice is wrong. The OP does not have to buy a sub with speaker level inputs. He can simply do as both myself and imhififan said and use a LOC.

Question for you, rbach, you really think "the perfect solution" is to sell two subs in order to buy two subs? You really think that is better than a $20 LOC? 

Really???!

If your budget is tight you may want to try this subwoofer:
https://www.parts-express.com/bic-venturi-v1020-10-160-watt-powered-subwoofer--303-430?gclid=CjwKCAjwh472BRAGEiwAvHVfGpz2RVPHoH2yMYFGKiB1fOotJTCDVHRtxqW7K0zbm3wgTTKQcUuGrxoCJNAQAvD_BwE

I've had one for about a year and I like it very much.
Very tight and musical.

Millercarbon,

That is wonderful information. Thanks. Why is no one listening? Oh, I know, they're too busy listening to  themselves.

I've noticed by some of your comments that we may have more in common than one would think. Besides a shared appreciation of the RSL 3600s I should tell you that I also go by SpdYlw993.

Yes call Svs they Have them Or can recommend the only thing you need is a 2 Pr of either spade or bananas crimp on and some awg 16 wire that plug in the speaker terminals   just Velcro’s 
to hold on I have a pair of Rca from there that plug into the sub.It’s also more accurate signal direct from speaker outputs

Call crutchfield for the subwoofer subwoofers adapter.
it has several small resistors under $30 ,you can buy 2 pair of
screw or crimp on bananas or spades you need to hookup
tp the loudspeaker terminals..

Millercarbon,

That is wonderful information. Thanks. Why is no one listening? Oh, I know, they're too busy listening to  themselves.

I've noticed by some of your comments that we may have more in common than one would think. Besides a shared appreciation of the RSL 3600s I should tell you that I also go by SpdYlw993.

Porsche Panorama Technical Editor Alan Caldwell had the most perfect 914 you ever saw. Speed Yellow over black. Al also had a Speed Yellow over Black SC. When he showed up at a concours with a brand new 996 I looked it over real good, walked up to Al and said, "Speed Yellow and Black?" Without missing a beat he said, "Is there anything else?"
When one day my wipers stopped returning to park I went looking for answers. None of the (seriously good) Porsche techs new for sure what it was. Unwilling to start throwing money at the problem but running out of ideas I turned to Al. "There’s a little copper tab inside the switch. It loses its spring after a while. With a toothpick you can bend it back." Sure enough. Saved me a thousand dollars. At least.

Pays to listen. It really does. Some of us figure it out.

Instead of using resistors, could a step down transformer be used on the amplified output?
For an example Jensen might have one off the shelf that could work?
I would certainly check the voltage with a multimeter after dropping the voltage for use with the sub.

Also, the sub itself has a volume control?

Your first response from "mattmiller" is a good one. First off I have several REL subs and they all have no peer in their price / performance category. Actually a pair of the entry level subs will do an amazing job when carefully set up. "Speaker level" connections are always the best way to go. Virtually all audio critics will agree to that. The REL's come with a cable that has a "speakon" connector to plug into the sub. The amplifier end can be connected parallel with the sattelite speakers. One sub parallel with each channel. The REL manual will provide info on the correct connectivity. There are also after market cables designed and terminated with quality connectors, that would be a slight upgrade from the ones supplied by REL. Also the supplied cables are quite long to accommodate almost any possible setup. Once you have determined the ideal locations for the subs, you should be able to buy the aftermarket version cut to a more appropriate length, unless you prefer to do it yourself. That's my recommendation !
"SPEAKER LEVEL CONNECTIONS" 

Congrats on interpreting the OP's query millercarbon. Good answer.

Maybe....
the OP states he owns the LM.
sometimes it is useful to ask a ? Or three before leaping...

so Dave the OP do you own the 2 subs yet ?

btw I prefer the 993 in Euro trim Adventurine Green a switchblade to the 996 X-50 Machine gun 

But it of course also leaves out the more delicate yet important surgery of high passing the amp, which if done right ( integrated w sub XO slope ) will yield incredible sonics....

in which case, I would pick a Vandersteen sub or two

davkobza4 posts05-14-2020 1:22am

I just placed my order for a pair of 4-10 subs with high-gloss obsidianschwarz (jet black) finish. These will accompany my Tekton Encores with same finish.

I found it from another thread. BTW, those 4-10 sub has speaker level input, so adapter is not needed.

https://www.tektondesign.com/uploads/9/8/4/7/98478018/4-10-amp-plate_orig.jpg

imhififan

Great to know! Thank you for pointing this out. And thank you everyone for your insight and information. 

millercarbon 

Great story hitting both subjects in one shot. Nicely done. Al is right. After you have one there is nothing else. Makes you smile every time you see it.

+1 rixthetrix, Contact Jensen transformers 

info@jensen-transformers.com

I had the same issue with an LTA integrated. They will give you exactly what you want, need in a quality unit for about $150.
very personable on the phone. (818) 374-5857

It took me a year to make a decision on choosing a subwoofer.  I decided to go with a pair of REL S2 SHO's and it was definitely the right way to go.  Their high level connection allows them to act as an additional woffer on my towers.  Takes time to dial everything in, but when you do it correctly they are seamless.  The only other sub I would go with would be Rythmik.

I run matching and separate amps and preamps to my mins and subs.  This gives total control of th bass without adding phase shift or tone control ramps. 

I would use a miniDSP SHD as the system front end and then use your Line Magnetics LM-508ia as a power amp. This will give you 100% control of crossovers, time delays, levels, room correction, etc.......  Dirac Live 2 correction puts the topping on the cake.