Speaker issue or Receiver?

[Dean Shias]

Hi all! ...I just purchased a used pair of KEF R700 from a credible source (KEF Employee). These speakers sound great to my ears! I noticed that when I try to listen to them loud with bassy or dance music the speakers cant seem to handle it, especially the bass. The sound starts to break down. So Im not sure if I need to upgrade my amp (Arcan AVR400), or is this how the speakers are? I previously had Def Tech 2006TL towers. They are over 15 years old.. loved them too but it was time (still kept them.. couldnt let go). At the moment they are biamped, but sounded this way before biamping. If it is a power thing... would keeping my Arcam as a preamp and maybe adding a Emotiva, Marantz, or Monoprice do the trick? Any suggestions would help! Thanks!

 

[lovinthehd]

Kinda depends how you define loud...and what distance you are from the speakers and the bass content of the music (and if you've got any eq boosting said bass). No experience with those speakers but they could max out at your high spl levels, too, especially without the support of a sub for bass heavy music. The avr looks to have reasonably good power into 8 and 4 ohms. Passive bi-amping from an avr is pretty much just extra wire rather than anything else, not a power thing. An external amp may not add much to the situation.

 

[Dean Shias]

Kinda depends how you define loud...and what distance you are from the speakers and the bass content of the music (and if you've got any eq boosting said bass). No experience with those speakers but they could max out at your high spl levels, too, especially without the support of a sub for bass heavy music. The avr looks to have reasonably good power into 8 and 4 ohms. Passive bi-amping from an avr is pretty much just extra wire rather than anything else, not a power thing. An external amp may not add much to the situation.

Im about 12 feet from front L&R&Sub. No EQ. The only setting on is whatever the mic found for room correction. Sub is crossed at 80hz. but speakers are set to Large (even when set to Small they handle just a tad more). I use to almost bring this receiver to the max with the def techs, lets say to 95 on the volume with no problem and they were more sensitive, but they do have built in subs to crossover low frequencies.. now I cant go past 74 to 80 without the KEFs sounding like they cant handle it. But again, Im not sure if its the speakers or receiver. The sound is so good on the KEFs that I dont mind if the KEFs cant handle bass or loud volumes this much, but just want to make sure they don't need to be serviced or not or if the receiver cant keep up. I listen to all types of music.. but the ones that I'm having a problem with at loud volumes is more like house, dance, and heavy metal music.

 

[lovinthehd]

Confused. The sub is crossed at 80 but set to large is usually contradictory but some avrs do have settings to enable both. I wouldn't set the low pass filter on the sub to 80 and still use a crossover in the avr, if that's what you mean.

What is the difference in sensitivity for the speakers? I didn't look it up....but will have a great impact on spl for the same amp power....

 

[Dean Shias]

Confused. The sub is crossed at 80 but set to large is usually contradictory but some avrs do have settings to enable both. I wouldn't set the low pass filter on the sub to 80 and still use a crossover in the avr, if that's what you mean.

What is the difference in sensitivity for the speakers? I didn't look it up....but will have a great impact on spl for the same amp power....

This receiver has both settings. Its basically running the main speakers at full range with the sub on. Its what the mic always calibrates it to. Even with the def techs. I had a tech from a high end audio store come to my house and told me to leave it to this position with the def techs. Not sure about the KEFs. They do sound better when set to large and sub at 80hz. Crossover is off on sub and receiver set it to 80hz. Sensitivity of Def Tech is 92db and KEF says its 89db (most source say actually its 87db). Would that make that much of difference?

 

[NINaudio]

Try setting your speakers to small with an 80 or 90 Hz crossover to see if that alleviates the issue.

 

[Dean Shias]

Try setting your speakers to small with an 80 or 90 Hz crossover to see if that alleviates the issue.

Tried that. No difference really.

 

[NINaudio]

Tried that. No difference really.

Have you tried an even higher crossover?

 

[Dean Shias]

Have you tried an even higher crossover?

Yes. It only makes a difference by one or two levels on the volume. Not even worth it. Too much emphasis on the sub in the corner. Im still more concerned with the mains playing at full range. I usually listen in stereo direct mode (with no sub). The whole point is if the speakers can handle high volumes and bass. I just havent heard anywhere of anyone having a problem with the KEFs, thats why im wondering if its a power issue from the receiver.

 

[lovinthehd]

The results of an auto setup sometimes need to be changed. Hard to believe double bass (using speakers as large plus some sort of redirected bass setting, like LFE+Main) sound same as using the crossover. How did you choose sub location?

 

[Dean Shias]

The results of an auto setup sometimes need to be changed. Hard to believe double bass (using speakers as large plus some sort of redirected bass setting, like LFE+Main) sound same as using the crossover. How did you choose sub location?

There is a big difference in sound, more bass with both on, but it didn't change the volume level in which the speakers started sounding like they couldn't handle it. I tried the auto setup 5 times. I listen more in direct stereo. So the sub is not on most of the time. Sub location was setup by the tech that came to my house. Im not so concerned about the sub as much as why the speakers cant handle the volume levels.

 

[TLS Guy]

I think you need a power amp.

Your speakers are not 8 ohm. The spec is 3.2 ohm minimal impedance. You can bet that will be where the power is in 80 to 400 Hz range. So the best rule of thumb to the impedance is minimal impedance + 10% which puts your speaker impedance around 3.5 ohms. The performance of your receiver is not specified at any impedance load. So there is no clue how it would perform into a load like that.

The speakers have a reputation of being capable. The amps in receivers are not very capable. Your receiver has preouts. I would strongly recommend using powerful external amplification before you blow up your receiver.

 

[Dean Shias]

I think you need a power amp.

Your speakers are not 8 ohm. The spec is 3.2 ohm minimal impedance. You can bet that will be where the power is in 80 to 400 Hz range. So the best rule of thumb to the impedance is minimal impedance + 10% which puts your speaker impedance around 3.5 ohms. The performance of your receiver is not specified at any impedance load. So there is no clue how it would perform into a load like that.

The speakers have a reputation of being capable. The amps in receivers are not very capable. Your receiver has preouts. I would strongly recommend using powerful external amplification before you blow up your receiver.

Thats what I was thinking too.. Didn't think I can possibly blow my receiver though. I guess Ill get on that suggestion... Fast! Thanks! (Good thing my wife is here to see you say it and not me

 

[Dean Shias]

I was looking at the Emotiva amps to add to the Arcam AVR400 receiver. Not sure which one to pick. I dont want too much or too little power. Is there one that is just right that you or anyone would suggest? Itll be for a 7.1 system. But I can also use the power from the Arcam for the surrounds if need be. I was looking at the Emotiva A-5175, A-700, or the XPA7 Gen3.

 

[lovinthehd]

Was thinking this would be a good alternative but out of stock for the next 8 months or so....https://www.monoprice.com/product?p_id=14566

The A700 isn't much more than you've already got, keep in mind it takes a doubling of power to gain 3dB...

If going to an external amp I'd personally add a Crown XLS1502 or two...

 

[Dean Shias]

Why the Crowns? Do they handle the 3.2 ohms? I see only 4 ohms on their specs. What would make them a better choice than the Emotiva or Monoliths? And for now until I get a separate amp is it ok to drive these with the Arcam AVR400 at low volumes? or should I just not use them until? Am i wrong to say that the Crowns distort more than the Emotiva? I dont want too much power where I might run the risk of blowing these speakers... like drinking too much wine one night and thinking I can crank it more than usual.

 

[NINaudio]

The crowns are stable down to 2 ohms, so you'd be fine there. Not sure how to help you out with the pushing it too far issue though....

 

[lovinthehd]

The Crowns are good even with 2ohm loads, they're more powerful than the amps you listed, have good connectivity options and some nice features like a clipping indicator and a limiter to protect your speakers and cost less...they're not as pretty, tho and don't have a lot of "0"s in the distortion specs. The level of distortion doesn't bother me in use (I have three of the 1500s from the first generation)....your speakers have more.

 

[Dean Shias]

With the Crown being that much more powerful but more distortion, would it matter so much considering I wouldnt have to turn it up so loud for the same volume? When does that distortion in the amplifier actually start becoming noticeable? If the Crown is definitely the better option then Ill order it today. (btw... Thanks for all the info from everyone)

 

[lovinthehd]

Not sure what you mean about turning it up to achieve the same volume....

Generally I think I've read you can hear something like 1% THD, think for IMD it's less. I haven't heard anyone complain about the distortion levels on these....several members here use these or other pro amps rather than consumer amps...can't guarantee your experience, tho