Between these two LCR options

C

curlyjive

Audioholic Intern
I'm looking at upgrading my current LCR setup. I have Polk RT600i LR and a CS400i Center.

I'm running a 7.2.2 setup with 2 SVS PB10 subs. I have a very limited set of options due to the space requirements of having both a LG C8 65 and a motorized tab tension screen being lit up by a JVC RS540. This makes speakers sizes and placement tricky.

Due to the fact that my co-worker works part time at Best Buy (yeah I know) I can get most speakers there for around 30-40% off.

I have on order a pair of SVS prime towers and an Ultra center. This will require me to raise up the towers about 2 inches and the center is gong to be a very tight fit in my semi-open AV shelf. The tweeter will be very close to the upper support bar of the shelf...as it is now with my CS400i

The other option would be the KEF Q750 and Q650c setup. This would place the towers are the right height and since the concentric driver is center mounted, the vertical spacing and interference from the upper part of the shelf is less of an issue.


This setup is really 100% movies/tv. I don't really do any critical 2 channel music listening.

My gut says the KEF would better for music and the SVS better for my use. I've looked the other popular ID options, ascend 340's, emotivas, but the above two options just "fit" the space the best.

Which would you guys go with?
 
Last edited:
TLS Guy

TLS Guy

Audioholic Slumlord
I'm looking at upgrading my current LCR setup. I have Polk RT600i LR and a CS400i Center.

I'm running a 7.2.2 setup with 2 SVS PB10 subs. I have a very limited set of options due to the space requirements of having both a LG C8 65 and a motorized tab tension screen being lit up by a JVC RS540. This makes speakers sizes and placement tricky.

Due to the fact that my co-worker works part time at Best Buy (yeah I know) I can get most speakers there for around 30-40% off.

I have on order a pair of SVS prime towers and an Ultra center. This will require me to raise up the towers about 2 inches and the center is gong to be a very tight fit in my semi-open AV shelf. The tweeter will be very close to the upper support bar of the shelf...as it is now with my CS400i

The other option would be the KEF Q750 and Q650c setup. This would place the towers are the right height and since the concentric driver is center mounted, the vertical spacing and interference from the upper part of the shelf is less of an issue.


This setup is really 100% movies/tv. I don't really do any critical 2 channel music listening.

My gut says the KEF would better for music and the SVS better for my use. I've looked the other popular ID options, ascend 340's, emotivas, but the above two options just "fit" the space the best.

Which would you guys go with?
Especially since you are using this system for HT almost exclusively, then the KEF option is by far the best. A coaxial design gives far and away the best speech clarity and quality. The MTM centers with the two bass mids either side of the tweeter are absolutely to be avoided. You do not have room for a three way center which is another option. So the choice is clearly in favor of KEF.
I selected a coaxial driver from SEAS licensed from KEF for my center and I could not be happier with it. I did extensive experimental and design work, before building that center. Center speakers are very hard to design, and successful center designs are way in the minority.
 
C

curlyjive

Audioholic Intern
Especially since you are using this system for HT almost exclusively, then the KEF option is by far the best. A coaxial design gives far and away the best speech clarity and quality. The MTM centers with the two bass mids either side of the tweeter are absolutely to be avoided. You do not have room for a three way center which is another option. So the choice is clearly in favor of KEF.
I selected a coaxial driver from SEAS licensed from KEF for my center and I could not be happier with it. I did extensive experimental and design work, before building that center. Center speakers are very hard to design, and successful center designs are way in the minority.

The SVS ultra is a 3 way center. Does that change your thinking? Most center channels out there in most Home Theaters are not Coaxial designs.
 
TLS Guy

TLS Guy

Audioholic Slumlord
The SVS ultra is a 3 way center. Does that change your thinking? Most center channels out there in most Home Theaters are not Coaxial designs.
Not really. I think a coaxial design is actually the best. I have designed and built both. I think the coaxial design is actually optimal for HT. KEF speakers are very good also. Those speakers do not have the deepest bass response, but adequate, and you have good subs. I have heard those KEF coaxials on a number of occasions now, and I'm very impressed with them. When all is said and done, it is the midband response that aces everything else.
 
C

curlyjive

Audioholic Intern
Not really. I think a coaxial design is actually the best. I have designed and built both. I think the coaxial design is actually optimal for HT. KEF speakers are very good also. Those speakers do not have the deepest bass response, but adequate, and you have good subs. I have heard those KEF coaxials on a number of occasions now, and I'm very impressed with them. When all is said and done, it is the midband response that aces everything else.
You're point about coaxial deigns makes sense.

Looking at the the other aspects of the SVS Prime Towers/ Ultra Center vs the KEF Q750, what else would you see as pros and cons of each?
 
TLS Guy

TLS Guy

Audioholic Slumlord
You're point about coaxial deigns makes sense.

Looking at the the other aspects of the SVS Prime Towers/ Ultra Center vs the KEF Q750, what else would you see as pros and cons of each?
I have not heard an SVS speaker for some time. However when I did I remember the bass as being somewhat over resonant. The SVS has a lower F3 than the KEFs. However that may well be its undoing. An F3 of 30 Hz is pretty low for 6.5" drivers. Now I have now been designing my own speakers for 67 years. Now this low F3 suggests what is known as an extended bass alignment as opposed to an optimal one. This is where the marketers put the hammer down on good designers to boast the most eye catching spec. My point is the bass quality aces bass extension.

The other issue, is that the SVS three way, crosses to the tweeter at 2.1 Hz, still right in the middle of the speech discrimination band. I can tell you this is a negative for speech clarity. If I go to the trouble of designing and building a three way then I make sure that the mid handles the whole of the speech discrimination band. For instance the mid in both my in wall and my family room cover 400Hz to 4 KHz and 350 Hz to 4 KHz respectively.
Otherwise a three way is generally at a disadvantage over a good two way design.

So to me the design of the KEFs seems to be the better engineering approach, especially for HT were voice quality is essentially of paramount importance. The reason is obvious, as it is understanding the speech at good conversational levels that is paramount about telling a story. Movies and TV programs are all about telling stories. So in any AV system natural speech should be at the very top in the design of any system, but especially for AV, and it so seldom is.
 
C

curlyjive

Audioholic Intern
I have not heard an SVS speaker for some time. However when I did I remember the bass as being somewhat over resonant. The SVS has a lower F3 than the KEFs. However that may well be its undoing. An F3 of 30 Hz is pretty low for 6.5" drivers. Now I have now been designing my own speakers for 67 years. Now this low F3 suggests what is known as an extended bass alignment as opposed to an optimal one. This is where the marketers put the hammer down on good designers to boast the most eye catching spec. My point is the bass quality aces bass extension.

The other issue, is that the SVS three way, crosses to the tweeter at 2.1 Hz, still right in the middle of the speech discrimination band. I can tell you this is a negative for speech clarity. If I go to the trouble of designing and building a three way then I make sure that the mid handles the whole of the speech discrimination band. For instance the mid in both my in wall and my family room cover 400Hz to 4 KHz and 350 Hz to 4 KHz respectively.
Otherwise a three way is generally at a disadvantage over a good two way design.

So to me the design of the KEFs seems to be the better engineering approach, especially for HT were voice quality is essentially of paramount importance. The reason is obvious, as it is understanding the speech at good conversational levels that is paramount about telling a story. Movies and TV programs are all about telling stories. So in any AV system natural speech should be at the very top in the design of any system, but especially for AV, and it so seldom is.

Well I switched my order to the KEF Q750 and Q650c. My gut was to go with the KEF over the SVS. I think I was drawn to having more active drivers on the SVS but like the UniQ concentric array on the KEF. The KEF center places the tweeter further away from the top of the shelf it will be in and it doesn't have ports so that may be a plus as well

I worry that the KEF will be better suited to music when I am using them for home theater, but I also worried that the SVS will sound too harsh.

Given that I currently have the Polk RT600i and CS400i I would hope either would be an upgrade?
 
Pogre

Pogre

Audioholic Overlord
Yeah, if the focus is home theater it's hard to argue against KEF's concentric drivers. It is the better design for a center channel, tho the Ultra center is no slouch. It's a 3 way design with a tweet above the midrange, flanked by the woofs.
 
William Lemmerhirt

William Lemmerhirt

Audioholic Warlord
I’d buy the KEF’s too, but I don’t feel the need to differentiate between HT and music. I’m a fan of both, and a good speaker is a good speaker.
 
C

curlyjive

Audioholic Intern
I’d buy the KEF’s too, but I don’t feel the need to differentiate between HT and music. I’m a fan of both, and a good speaker is a good speaker.
In theory this seems logical to me too. Music can be just as dynamic as a move surround track.
In practice I don’t know if it’s fair that some speakers might be better suited to one task or the other.

I hope I made the right choice over the svs prime towers and ultra surround. I also hope this is an upgrade over my my rt600i cs400i fronts currently.

I’ve been back and forth and as soon as I think I’m good with my choice I doubt it again.

the svs speakers tend to be more favored for home theater use. I’m hoping the kef q650c isn’t an afterthought center compared to the ultra. The prime towers get knocked for harshness and being over priced. They do have more active drivers but that doesn’t make them better. The cabinets of the svs seem more solid. That may be because they isolate the drivers where kef can’t as much because of the passive radiators.

I like the concentric driver concept and the overall flat black look. I did order grills.

i just upgraded to a Denon 4700 with svs prime elevations ceiling mounted for atmos. So that led me to look svs first. I know marching surrounds is less important and in reality the elevations blend fine with my 4 Polk rti4 surrounds despite being very different.

needless to say I’m still Second guessing myselfas I was when I had the svs on order.
 
C

curlyjive

Audioholic Intern
Well i didn’t think of this but I think lower driver (not just the lower radiator) on the right speaker will be partially occluded by the side couch. I hope that won’t be too much of a problem. There is 3 feet between the speaker and couch.
Deal breaker or not that big of an issue?
https://share.icloud.com/photos/0SnU0mIhSQ7mcR4JfBvLn3GsA#Abington
 
Last edited:
C

curlyjive

Audioholic Intern
Well, might be going to plan A (SVS) I don't know that the mid bass being occluded like that is just not going to work out well.
 
C

curlyjive

Audioholic Intern
I have not heard an SVS speaker for some time. However when I did I remember the bass as being somewhat over resonant. The SVS has a lower F3 than the KEFs. However that may well be its undoing. An F3 of 30 Hz is pretty low for 6.5" drivers. Now I have now been designing my own speakers for 67 years. Now this low F3 suggests what is known as an extended bass alignment as opposed to an optimal one. This is where the marketers put the hammer down on good designers to boast the most eye catching spec. My point is the bass quality aces bass extension.

The other issue, is that the SVS three way, crosses to the tweeter at 2.1 Hz, still right in the middle of the speech discrimination band. I can tell you this is a negative for speech clarity. If I go to the trouble of designing and building a three way then I make sure that the mid handles the whole of the speech discrimination band. For instance the mid in both my in wall and my family room cover 400Hz to 4 KHz and 350 Hz to 4 KHz respectively.
Otherwise a three way is generally at a disadvantage over a good two way design.

So to me the design of the KEFs seems to be the better engineering approach, especially for HT were voice quality is essentially of paramount importance. The reason is obvious, as it is understanding the speech at good conversational levels that is paramount about telling a story. Movies and TV programs are all about telling stories. So in any AV system natural speech should be at the very top in the design of any system, but especially for AV, and it so seldom is.

I was looking at the KEF Specs. They have the crossover listed as 2.5kHz, not sure how much that helps dialogue? I have not been able to find out the crossover to the lower bass driver, no one there seems to be able to tell me.

A common statement made by several has been the SVS are "more dynamic" and therefore better for home theater while the KEFs are better for music. I dont know how to quantify "dynamic" in this sense. I do see a lot of peoples KEF setups are 2 channel music only.

Then there is the view expressed in this thread that a good speaker is a good speaker. Also seems true, but are certain speakers just better for certain uses? Do some work better for movies and handling loud music, dialogue and effects all at the same time?

I know SVS is a better known company in the US, so I just dont know as much about KEF. I am really intrigued by their design. I do wonder about the cabinet construction as the SVS seem to be more braced and less hollow. I will say both have answered my questions and KEF even called me to discuss the concern I had about the couch being in the way. I think both offer good support. Honestly other than abuse a speaker usually doesn't just fail.

Bottom line is I'm still stuck. The two people I have heard from that are reputable recommending the SVS for HT use stick in my head, but there is also something about the KEF design that appeals to me.
 
James S.

James S.

Audioholic Intern
I can't speak to the KEF as I have never heard them. I have SVS Prime Pinnacles and an Ultra center and I love them for my home theater.
 
C

curlyjive

Audioholic Intern
I can't speak to the KEF as I have never heard them. I have SVS Prime Pinnacles and an Ultra center and I love them for my home theater.

The pinnacles are a bit better than the standard Prime Towers. I can't fit those height wise.
 
Last edited:
C

curlyjive

Audioholic Intern
I went with the KEF q750/q650c setup. So far there is no way to classify these are bright. They are laid back compared to the SVS and the Polks I have. The sound stage is very large.

I am having issues with detail and dialogue. In looking at what Audyssey is measuring (and for what its worth this lines up with what I am hearing) The natural response of these in my room has a lot of high frequency slope. This makes them sound a bit flat or dull especially for movies. The example I really noticed it on is the Atmos demo "Shatter" which is a baseball chattering a window. The glass breaking sounds dull and not at all like glass. With Audyssey limited to 300Hz or off, this is the case. If I let Audyssey run full range those details are much better and glass sounds like glass. This also creates some brightness in the upper mid of dialogue in certain voices. Its not SSS sibilance, just a sharpness. Seeing the target rolloff curve to #2 helps a bit, but I do plan to run it again and play with some different Mic placements.

Music can be hit or miss with Audessey, as some tracks sound better with and some without.


The other issue is dialogue in general especially streaming and cable sources. They have much more noticeable what I would describe as almost a rustling of paper sound...like a compression artifact. I'd almost think there was a problem with the speaker but I don't hear it on most disc based sources. I think I noticed it a bit watching the Game of Thrones UHD discs though. Of course I know compressed sources are a problem and can't blame the speaker, it just wasnt as problematic with the Polk CS400i I was using for decades.


So I'm left wondering. Are the KEFs just a more revealing speaker? Are they just not as good as the Rt600i CS400i I had....which I am loath to believe. Is the 650c just not a well designed center? Are they really designed to be so rolled off as to lack detail or is it my room absorbing those frequencies and needing Audyssey to correct?


I've attached the graphs and while I know the corrected graph is merely a prediction, and even the measured side may not be the best accuracy, it does line up with what I am hearing. you can see the drop-off from 1khz on.

6B79FA87-0CDE-4E84-8BD2-ED6649686E69.png

0ECFDED5-0209-40A0-A5D3-28BB9AE981F2.png

59288F4B-1410-4492-B9A9-C20B309AEA75.png
 
TLS Guy

TLS Guy

Audioholic Slumlord
I went with the KEF q750/q650c setup. So far there is no way to classify these are bright. They are laid back compared to the SVS and the Polks I have. The sound stage is very large.

I am having issues with detail and dialogue. In looking at what Audyssey is measuring (and for what its worth this lines up with what I am hearing) The natural response of these in my room has a lot of high frequency slope. This makes them sound a bit flat or dull especially for movies. The example I really noticed it on is the Atmos demo "Shatter" which is a baseball chattering a window. The glass breaking sounds dull and not at all like glass. With Audyssey limited to 300Hz or off, this is the case. If I let Audyssey run full range those details are much better and glass sounds like glass. This also creates some brightness in the upper mid of dialogue in certain voices. Its not SSS sibilance, just a sharpness. Seeing the target rolloff curve to #2 helps a bit, but I do plan to run it again and play with some different Mic placements.

Music can be hit or miss with Audessey, as some tracks sound better with and some without.


The other issue is dialogue in general especially streaming and cable sources. They have much more noticeable what I would describe as almost a rustling of paper sound...like a compression artifact. I'd almost think there was a problem with the speaker but I don't hear it on most disc based sources. I think I noticed it a bit watching the Game of Thrones UHD discs though. Of course I know compressed sources are a problem and can't blame the speaker, it just wasnt as problematic with the Polk CS400i I was using for decades.


So I'm left wondering. Are the KEFs just a more revealing speaker? Are they just not as good as the Rt600i CS400i I had....which I am loath to believe. Is the 650c just not a well designed center? Are they really designed to be so rolled off as to lack detail or is it my room absorbing those frequencies and needing Audyssey to correct?


I've attached the graphs and while I know the corrected graph is merely a prediction, and even the measured side may not be the best accuracy, it does line up with what I am hearing. you can see the drop-off from 1khz on.

View attachment 47116
View attachment 47117
View attachment 47118
Actually it looks very good. When you measure at a distance, you will and should see a downward sloping HF response. This is because of the change of balance between direct and reflected sound. So I do not correct for this, as you would not if someone was talking in the room.

A lot of your problems I have noted here are related to center speaker placement. So a picture of your speaker layout would be very helpful. The fact you have a nice wide soundstage is very encouraging.

One of the big issues with centers is that for obvious reasons the center speakers gets placed too low. So I have my theater center above the screen.

This is my center response. The coaxial driver is very similar to yours in many respects.



This is the total system response at the main listening position. There is no Audyssey correction, and I don't use it. You will see there is a sloping HF response at this center second row seat. Voice clarity is excellent as well as very natural.



This is the layout.



The center has a sloping front panel directed at the seating area.

So from the look of what you posted, my first guess is probably interference from boundary effects near your center speaker.
 
C

curlyjive

Audioholic Intern
That's encouraging. I still fee like without correcting for that drop-off the sound is too dull. So I am OK with letting Audyssey correct for it since it pulls out those details without making things harsh.

As for the center, no it is not an ideal placement. Same went for my Polk. Is on an AV shelf below the TV. There is no easy way around this. While I do expect this to cause some issues, the emphasis on that rustling sound in the dialogue seems odd. With my Cs400i, I had to get creative with Mic placement but I eventually got a calibration that made dialogue and center in general completely acceptable to me. Also feel like the q650c is drawing attention to itself more as a point source.


I'm sure you'll cringe at the placement. If I move it up, the TV sill need to be raised as well and I'm not a fan of doing that. Above pointed down isn't an option because I have a screen than comes down for my projector. The polk was probably worse off as the the tweeter was up much higher instead of being centered. The problem with the Polk was overly sibilant diaogue, which made sense since Audyssey XT "heard" an off axis response and overcompensated. XT 32 did a much better job and didn't introduce nearly as much of that.

It's odd with the Q650c. It can sound great, and then bad. Even amongst the same dialogue sequences. Some of it I have to think is due to it being a more revealing speaker and making the flaws of streamed sources more noticeable. Some of it is placement and I am going to try some of the same "tricks" I used to get the Polk sounding good.

But I also wonder, have I actually downgraded my LCRs? Is this a better speaker than the CS400i? I have a hard time believing that. But I had the dialogue pretty perfect and the mains never lacked for detail with the polk, even limited to 200hz correction.

IMG_7576.jpeg
 
TLS Guy

TLS Guy

Audioholic Slumlord
That's encouraging. I still fee like without correcting for that drop-off the sound is too dull. So I am OK with letting Audyssey correct for it since it pulls out those details without making things harsh.

As for the center, no it is not an ideal placement. Same went for my Polk. Is on an AV shelf below the TV. There is no easy way around this. While I do expect this to cause some issues, the emphasis on that rustling sound in the dialogue seems odd. With my Cs400i, I had to get creative with Mic placement but I eventually got a calibration that made dialogue and center in general completely acceptable to me. Also feel like the q650c is drawing attention to itself more as a point source.


I'm sure you'll cringe at the placement. If I move it up, the TV sill need to be raised as well and I'm not a fan of doing that. Above pointed down isn't an option because I have a screen than comes down for my projector. The polk was probably worse off as the the tweeter was up much higher instead of being centered. The problem with the Polk was overly sibilant diaogue, which made sense since Audyssey XT "heard" an off axis response and overcompensated. XT 32 did a much better job and didn't introduce nearly as much of that.

It's odd with the Q650c. It can sound great, and then bad. Even amongst the same dialogue sequences. Some of it I have to think is due to it being a more revealing speaker and making the flaws of streamed sources more noticeable. Some of it is placement and I am going to try some of the same "tricks" I used to get the Polk sounding good.

But I also wonder, have I actually downgraded my LCRs? Is this a better speaker than the CS400i? I have a hard time believing that. But I had the dialogue pretty perfect and the mains never lacked for detail with the polk, even limited to 200hz correction.

View attachment 47120
As I suspected, your entire problem is due to placement. Unless you correct that, you will continue with unresolved problems. No amount of tinkering will make up for that, or correct it.

If you can't correct it, you may well be better off without a center. How does is sound without a center? I have a sense it will be an improvement.
I'm certain there are a lot of systems downgraded by having a center. BBC engineering thinks so as well. They refuse to include a center channel in multichannel broadcasts.
 
C

curlyjive

Audioholic Intern
As I suspected, your entire problem is due to placement. Unless you correct that, you will continue with unresolved problems. No amount of tinkering will make up for that, or correct it.

If you can't correct it, you may well be better off without a center. How does is sound without a center? I have a sense it will be an improvement.
I'm certain there are a lot of systems downgraded by having a center. BBC engineering thinks so as well. They refuse to include a center channel in multichannel broadcasts.

Which issues are you saying are placement related and what would their sonic impact be? I'm not so sure I can't get acceptable results tinkering....I've done it before and ran that way for over 10 years with the Polks and to my ears it was pretty darn good. Worst case I have to go back to them. I have a hard time believing the rustling artifacts in the dialogue are due to placement. Also the dullness I hear above 1K in the mains isn't due to placement.

You're certainly not the first person to point out the placement issue, yet I've made it work sonically. So while it may not be textbook pretty I've had success even with this compromise. Maybe I'm used to hearing those compromises. But there is something different up here and even when I had the 650c on a stand in front of the tv to test it before I placed it in the shelf, I still heard the same thing.

I won't ditch the center. I've never found that acceptable. Again worst case is I got back to the using the Polks‍:eek:
 

newsletter
  • RBHsound.com
  • BlueJeansCable.com
  • SVS Sound Subwoofers
  • Experience the Martin Logan Montis
Top