LSiM Home Theater Amp Advice

hlshure · December 2017

Hey everyone. First time posting. Just picked up a 7 speaker LSiM kit from Adorama (707, 706c, 703, 702F/X) and a Yamaha rx-a2070. From all the research I've done I believe I'll need to get an amp to get the best out of this setup. My question is whether or not I need a 2 channel for the 707's only or a 3 channel and run the 706c off the amp as well. Let me also say that I am 90% movies and tv although that may change after I get this setup. As far as brands I think most of what I have read leads me to Emotiva or Parasound.

Room is 18x15 with a slope vaulted ceiling starting at 12' left and raising to about 15' on the right. Room is also about 60% open on the right side.

I appreciate any and all advice.

Thanks!

txcoastal1 · December 2017

2chnl parasound

hlshure · December 2017

@txcoastal1 - thanks for the response. Is there a particular one that you would recommend? Preferably one I might be able to find pre-owned to save some $$. What about the Parasound 2250 v2 ? Would that work well?

Nightfall · December 2017

It's too bad you were so far into the line on that B&K.

hlshure · December 2017

Another quick question. Would you guys run the 707's full for the HT or small and cross over at 80hz. I've always run small and crossed at 80hz but I've also never had speakers of this caliber before.

hlshure · December 2017

Nightfall wrote: »

It's too bad you were so far into the line on that B&K.

I know! I was pretty bummed. Would have been perfect.

txcoastal1 · December 2017

hlshure wrote: »

@txcoastal1 - thanks for the response. Is there a particular one that you would recommend? Preferably one I might be able to find pre-owned to save some $$. What about the Parasound 2250 v2 ? Would that work well?

If you can the budget for the A21 that would be great, but nothing wrong w/ Model 2250 v.2

As for large or small would only depend if you're running a sub
Large=no sub
Small=sub

If you have a sub, and you're watching a movie, cross at 80, when listening to music play with it and blend sub to speakers and music...you may find 60 might blend well since the 707 can handle curve pretty well

Good luck

TNTsTunes · December 2017

I would personally use a 3 channel amp for voicing reasons with the speakers set at large and a healthy sub meant to dig deep crossed over at around 50-60hz.

The LSIM7's subwoofer crossover point is at 100hz and their -3dB spec is 50 Hz – 30 kHz

ken brydson · December 2017

hlshure wrote: »

Another quick question. Would you guys run the 707's full for the HT or small and cross over at 80hz. I've always run small and crossed at 80hz but I've also never had speakers of this caliber before.

Do you have a sub? If so, let it handle the low stuff. If not, run them full range.

rooftop59 · December 2017

As a general rule of thumb, speakers that can hit 35hz @ -3db can and probably should be run full range for HT. Per professional reviews the LSiM707 are -3db @34 and -6 @ 30, so I would run them full range. Let your sub handle the LFE track and then lows from the other channels.

https://www.soundandvision.com/content/polk-lsim707-surround-speaker-system-ht-labs-measures

rooftop59 · December 2017

As for an amp, I think I would just get a good 2 channel. If you decide the center using quite cutting it, either get a minoblock or upgrade to a 3 or 5 channel.

Earthy · December 2017

Not trying to hijack you thread, but similar question. My HT is 15x14x8 enclosed. I picked up a Denon AVR-x6400h before finding the deal on a full 7 speaker LSiM 707 kit. Will the 140 watts be enough to drive those 707's in my smallish space or do I need to go snag my A21 from my SDA setup on movie nights?

hlshure · December 2017

Thanks everyone for the great feedback. I should have mentioned that I have a HSU sub which I love and highly recommend. I think I’m going to try running the system both ways and see which one sounds better to me, but running the 707’s full range seems to make sense. As for The amp, I’m leaning towards a Parasound 2250 v2 as I can’t afford the a21 right now.

By the way, I’m upgrading from TSx440t towers,TSx250c center, and a Yamaha rx-A730. I’m guessing that alone should be a huge difference. Just curious if anyone has actually heard both and can give me their opinion since I’ve not actually heard the LSiM series speakers before.

hlshure · December 2017

Earthy wrote: »

Not trying to hijack you thread, but similar question. My HT is 15x14x8 enclosed. I picked up a Denon AVR-x6400h before finding the deal on a full 7 speaker LSiM 707 kit. Will the 140 watts be enough to drive those 707's in my smallish space or do I need to go snag my A21 from my SDA setup on movie nights?

No worries. Ask away! I’m jealous of your a21. Hoping my rx-a2070 will be good enough for a little while until I can get an amp.

hlshure · December 2017

rooftop59 wrote: »

As a general rule of thumb, speakers that can hit 35hz @ -3db can and probably should be run full range for HT. Per professional reviews the LSiM707 are -3db @34 and -6 @ 30, so I would run them full range. Let your sub handle the LFE track and then lows from the other channels.

https://www.soundandvision.com/content/polk-lsim707-surround-speaker-system-ht-labs-measures

Thanks for the link. I enjoyed reading the review.

WLDock · December 2017

The OP did say 90% movies right? What's the average listening level? Movies at reference? Near reference? or normal levels where you can still have a conversation during an action movie?

That 2070 is an awesome unit that many will be just fine with running, 5, 7, 9 channels. However, if one thinks the towers need external amps why stop there for a 90% movie/tv system? About 70% of movie dialog, effects, music, etc can come from the center at times. The 706C is a SERIOUS center speaker... I've had one and listened to an Emotiva demo system using the 707 & 706C upfront. It will come alive as well with power reserve on tap and it won't distort during the big effects scenes from movies like Pacific Rim, Transformers, etc. In my system it even help center the bass effects. Here is the Emotive demo system that played if a fairly large space.

Get at least a 3 channel or 5 channel. Go for 200W a channel! Something like this:

Parasound HCA-2003
https://www.ebay.com/itm/Parasound-HCA-2003-3-Channel-Power-Amplifier/202151023793?hash=item2f1123d4b1:g:l28AAOSwTm9aNtb~

B&K 200.5
https://www.ebay.com/itm/B-K-Components-Reference-200-5-Power-Amplifier-5-Channel-AMP/252933077838?hash=item3ae3fc7b4e:g:ywUAAOSwqfpZwrHa

Sunfire Cinema Grand
https://www.ebay.com/itm/sunfire-cinema-grand/282776354899?hash=item41d6c8c053:g:Sg4AAOSwYxBaNsbi

cfrizz · December 2017

I totally agree with WLDock! Just watch the volume level and save more money and get a 5 channel 200wpc amp and be done with that upgrade.

I'm partial to the Sunfire, since I have one myself, but the B&K would get the job done as well.

hlshure · December 2017

@WLDock @cfrizz
Thanks for the advice. I really appreciate it. It’s funny that you mention the HCA-2003 because I was just looking at that last night. It’s actually the one you linked. I might have to snag that.

Everyone has been really helpful and I appreciate everyone taking the time.

Happy Holidays!

hlshure · December 2017

Ok. Didn’t take long and I’m back for more. I have an opportunity to pick up a parasound 5125 for about $500. I believe it is 125 wpc x 5 channels and I’m not sure if that’s enough to power the 707’s. Any thoughts? Am I better getting the HCA-2003?

TNTsTunes · December 2017

HCA-2003 for the win

EndersShadow · December 2017

hlshure wrote: »

Ok. Didn’t take long and I’m back for more. I have an opportunity to pick up a parasound 5125 for about $500. I believe it is 125 wpc x 5 channels and I’m not sure if that’s enough to power the 707’s. Any thoughts? Am I better getting the HCA-2003?

Buy both

. HCA-2003 for front 3, 5125 for surrounds (with one channel unused).

Also, how much wattage you need depends on how loud you listen and how big your room is. 125 wpc for your front three MAY be enough, may not.

If your unsure, its ALWAYS better to have more power than you think you'd need, so I'd go with the HCA-2003 for your front 3.

And if it was me, I'd look (at a later date when I could afford it) buying a second amp to run the surrounds. Your fine running them off the AVR to start with, and maybe to do that forever, but a dedicated amp for your surrounds should provide some improvements and you don't need it to have a ton of power either.

PS: Welcome to Club Polk, and also the big league. Those are some really nice speakers and your doing it right by looking for a dedicated amp for them. They will reward you in kind

hlshure · December 2017

Thanks @EndersShadow. I just received everything today and hooked up the the 707’s and 706 to the 2070. Sounds good, much better than my TSx440t’s, but I can tell they are wanting more power. Gonna try and get that HCA-2003 soon and go for something smaller in the near future for the surrounds.

cfrizz · December 2017

Congrats and enjoy.

tonyb · December 2017

hlshure wrote: »

Thanks @EndersShadow. I just received everything today and hooked up the the 707’s and 706 to the 2070. Sounds good, much better than my TSx440t’s, but I can tell they are wanting more power. Gonna try and get that HCA-2003 soon and go for something smaller in the near future for the surrounds.

Let the receiver handle the surrounds. Surround information is mostly ambient sounds and not too taxing on receivers. Plus once you take the load off the receiver with an amp for the front 2 or 3 speakers, the receiver will have ample power for just the surrounds.

WLDock · December 2017

I concur with Tony. With just a 5 channel theater, the 2070 might do well just driving the 702's. Most would be just fine with this setup.... Don't bother getting a smaller 100W x 2 or something amp later.

However, If you do decide to get a second amp or a massive 5 channel amp , again go for a 200W-250W x 2 two channel or a 200W-250W 5 channel like that B&K 200.5, Parasound 5250, etc. These are $1500, 28lbs, Polk's flagship dedicated surround speakers. These are have 88dB efficiency. Push then hell out of them! heavy HT hitters use more efficient speakers and horn technology to get there. That's what a high powered mega buck surround system is all about. Polk knows about filling a room with BIG expansive sound.... look at its heritage SRT, SRS, SDA, etc...

Then put on a BluRay like Pacific Rim, Transformers, The Great Wall, Gravity, Tron, The Dark Knight, Master and Commander, etc. and come back and report your thoughts. If the added power does not present itself then you can always go back to a 3 channel.

Earthy · December 2017

I watched Guardians of the Galaxy with my Denon X6400h 140wpc driving my 707's 706c and 703's. No sub. It had no trouble sounding amazing. I don't know how to tell if it's struggling but the sound was crisp and clean.

EndersShadow · December 2017

tonyb wrote: »

hlshure wrote: »

Thanks @EndersShadow. I just received everything today and hooked up the the 707’s and 706 to the 2070. Sounds good, much better than my TSx440t’s, but I can tell they are wanting more power. Gonna try and get that HCA-2003 soon and go for something smaller in the near future for the surrounds.

Let the receiver handle the surrounds. Surround information is mostly ambient sounds and not too taxing on receivers. Plus once you take the load off the receiver with an amp for the front 2 or 3 speakers, the receiver will have ample power for just the surrounds.

WLDock wrote: »

I concur with Tony. With just a 5 channel theater, the 2070 might do well just driving the 702's. Most would be just fine with this setup.... Don't bother getting a smaller 100W x 2 or something amp later.

However, If you do decide to get a second amp or a massive 5 channel amp , again go for a 200W-250W x 2 two channel or a 200W-250W 5 channel like that B&K 200.5, Parasound 5250, etc. These are $1500, 28lbs, Polk's flagship dedicated surround speakers. These are have 88dB efficiency. Push then hell out of them! heavy HT hitters use more efficient speakers and horn technology to get there. That's what a high powered mega buck surround system is all about. Polk knows about filling a room with BIG expansive sound.... look at its heritage SRT, SRS, SDA, etc...

Then put on a BluRay like Pacific Rim, Transformers, The Great Wall, Gravity, Tron, The Dark Knight, Master and Commander, etc. and come back and report your thoughts. If the added power does not present itself then you can always go back to a 3 channel.

I dont disagree, but I want to point out he's running 2 sets of surrounds now (7 channel setup bought from Adorama).... 703's and 702's... if he wants to go Atmos at some point then you'd really start to tax the AVR IMHO.

I've seen the impedance graphs of the LSiM's and they are a 8 ohm load, but there are parts where the dip lower. It "shouldn't" be an issue as most of those areas are sub 80hz (where you would cross over surrounds), but its worth mentioning.

hlshure · December 2017

Appreciate the responses! To clarify, I’m probably gonna sell the 703’s and just run a 5.1 for right now and then eventually add atmos speakers for a 5.1.2 or 5.1.4 as I don’t have wall space for a 7.1 system. My main focus are the 707’s and the 706. Anyone have any thoughts on bi-amping and whether or not it’s worth the effort? Does that effectively double the power to the left and rights using the 2 unused channels in my receiver? Just checking into this option to hold me over in case I can’t find an amp within my current budget. Read a few threads with conflicting info and figured since you guys know my situation I’d get your take on it.

@Earthy - I haven’t had a chance to watch too much yet but I will definitely watch Guardians of the Galaxy tomorrow and check it out.

rpf65 · December 2017

Guess you can spend the money on a 5-channel amp and give it a shot. Some people hear a difference, others don't.

With the 707's, if you run a conventional, single set, of wires to your speakers, probably about 75 percent of the available current will be directed to the woofers. The tweeters will use about 1 or 2 percent.

Running a 2-channel amp to the each set of woofers, and the AVR to the mids/tweeters, will probably degrade sound quality. Again, you can give it a shot, but I think conventional wiring will be the better bet.

Either way, you'll only be out the extra cost of the wire to experiment.

Personally I would invest the money from the extra set of wires on good quality wires and jumpers, but that's just me. Your ears, are different than mine.

EndersShadow · December 2017

Bi amp isn’t worth it. Forget the idea and move on. I’ve don’e it and it’s wasn’t noticeableuntil beyond stupid levels

WLDock · December 2017

Leave Bi-Amping to the guys with the mega buck $50K-$500K systems, $1K-$10K cables, in treated dedicated rooms that state that they can hear a different.

Polk LSiM driven by 200W x 2 in the average home...why bother with bi-amping?
If you have never tried it, do it at least once to see for your self. I've never had home audio gear I felt was worthy. However, I have done in in car audio for various reasons. Was mainly running an all active system with independent DSP on all channels. That's a totally different thing.....

...Just don't get caught up in Bi-Amping, Get a 2, 3, or 5 channel amp and enjoy!

LSiM Home Theater Amp Advice

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