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Classe Amp/B & W 702 S2/Rotel Sounds Horrible

20K views 125 replies 29 participants last post by  giteshb 
#1 ·
I have a Classe CA-200, B & W 702 S2 and a Rotel RC-1070 in a carpeted 24' x 13' basement room. It sounds horrible and ear fatigue within an hour.

Should these components pair well and my sights be set on room treatment? Or, is the Classe & Rotel outdated?

Thanks for any and all replies!
 
#2 ·
I would blame lack of room treatments/acoustic treatments and then the speakers. Some people do not get along with aluminum dome tweeters very well. Unless there is something wrong with your amp and preamp, I would blame those last as they will have less of an affect on the sound than the speakers and room do.
 
#9 ·
The upper midrange and treble of B&W loudspeakers cause me listening fatigue, too.

Unfortunately your Rotel preamp does not have a tone control to reduce the treble (the Contour control increases treble). Have you tried angling the speakers away from the listening seat and/or sitting in a much taller chair?
 
#10 ·
Before spending any money, learn something about speaker placement, experiment first before blaming anything. It really make a big difference. Before I do speakers placement experiment, I did buy a panel, thought that helped, BUT after I played with the speakers placement, the panel doesn't improve the sound anymore.


Speaker placement is very very critical, turning the speaker a few degrees make a difference in the sound. I am not in position to advice, someone more experience definitely can help you.
 
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#11 ·
I had new black carpet installed 2 days ago and it's still empty except for a large counter high cabinet. Also, my components are flush mounted through the wall and ready to go. Is there an advantage to find the best speaker placement now and fine tune after adding seating and misc or complete the setup before starting?

Are these 702's junk?
 
#16 ·
I had new black carpet installed 2 days ago and it's still empty except for a large counter high cabinet. Also, my components are flush mounted through the wall and ready to go. Is there an advantage to find the best speaker placement now and fine tune after adding seating and misc or complete the setup before starting?



Are these 702's junk?

Yes.

And despite the common conception that everyone “thinks” they have their own preference in sound signature from speakers, you don’t.

Blind ABX tested, speakers with flat(er) listening window responses (and with bass not a factor) are preferred 99.5% of the time.

B&W speakers are far from this. Try out a pair of Revel speakers, or the Ascends I mentioned which are indeed flat response speakers.

The response is good from the get go, no EQ, no physical devices to tame the response, etc.

The anemic bass is also a problem. If there was more bass from the speaker itself, it would cause a spectral shift for the speaker to sound warmer and less harsh.
 
#12 · (Edited)
They are not junk. Everyone has their own taste in sound. It yes you need to setup your listening space and then position your speakers and treat the room if needed.

By the way there’s a good review of the speakers in Stereophile from 2018.
 
#13 ·
Draping thin carpet over hard walls isn't going to do much for the acoustics in any room, much less one that has little or no furniture and other soft items that can help absorb harsh highs. You should get the room set up the way you intend to use it before condemning the speakers. I've read that the B&W 702's are rather harsh, and lack decent bass response. I've never heard them so I can only go by what other have to say. Good luck with your setup.
 
#14 ·
Thanks for the "not so gloom" comments and advice.

The thin wall carpet was a cheap way to enhance a poker room some 15 years ago. I hope the new floor carpet helps and will order some acoustic diffusers & absorbers. I think one can find pros and cons for any component combo on the net and feared I paired a real looser after hearing.

Any suggestions for acoustic panels with a cap of around $1500?
 
#15 ·
As MSchott said about your B&W loudspeakers, "They are not junk. Everyone has their own taste in sound."

Heavy curtains and drapes with a lining work well. I use the Sonora acoustic wall panels linked below in our theater and music rooms. They come in many colors and sizes and are very attractive.

http://www.acousticsfirst.com/sonora-wall-panels.htm

http://www.acousticsfirst.com/guilford-of-maine-fr701-style-2100-color-chart.htm

http://www.acousticsfirst.com/docs/ (see Material Price Sheet, page 9)
 
#18 · (Edited)
I'm not sure why everyone is ragging on the B&W 702-S2. I've auditioned these speaker several times and am absolutely not hearing what other people are claiming. They do have a crisp detailed Mid/High but at the same time maintain a smoothness and lack of harshness that can be found in some speakers. To my ear, which are admittedly old, these speakers came off very clear and well balanced. I've definitely heard better but for considerably more money.

As others are suggesting, the problem is either the wiring or the room. For every system the first thing I recommend is that you ABSOLUTELY BEYOND ANY SHADOW OF A DOUBT make sure the speakers are wired correctly. That in every case the Amp(RED+) goes to the Speaker(RED+). Nothing will suck the life out of a speaker like one of them being wired backwards.

Next where are the speakers in the room? If they are on the 24ft wall playing into the 13ft space, that could explain a lot. If they are on the 13ft wall playing into the 24ft space that is certainly better.

The next aspect that must be asked is, where are the speakers place relative to nearby walls. Placement is always a big issue. If the speaker are against the back or side wall then that explains a lot. If you put your speaker near a boundary surface, that boosts the bass, but what you hear is the Mid/High becoming more recessed and muddy. Placement issues are easy to determine. As a test, simply pull the speakers forward about 3 to 4 feet into the room and at least 3ft away from the side wall. If the speakers now sound better, then you have a Placement problem. Once that is determined, start working the speaker back until you find a workable compromise.

Most people, for some odd reason, push their speaks way too far back against the wall. For myself, I simply move the speaker forward even with the front of my equipment stand which is itself about 8" forward of the wall behind. That gives me in the range of 14" behind the speaker, which, while not perfect, works for me.

Also, you might try plugging the Port if the speakers must be relatively closely placed. That will soften the bass profile of the speakers, and as the bass is softened, the Mid/High becomes more clear.

Classe are good amps from what I can determine. The Rotel Pre-Amp should be fine. And in my opinion, the B&W 702-S2 are fine speakers, though we each have our own taste. That means that something else is probably the problem.

- Speaker Wiring - Even the best of us get this wrong on occasion. Absolutely verify it.
- Speaker Placement - the most often made mistake. As indicated, a simple test can verify if this is the problem.
- Plug the Ports - this can soften the bass, and clear up Mid/High
- Room Acoustics - Highly reflective walls can definitely blur the sound.

Also if you can explain how the speakers are not sounding right? Too much bass, not enough bass? Blurred muddy Mid/High? Other? Understanding how the speakers don't sound right would help us understand why the speakers don't sound right.

Just a few thoughts.

Steve/bluewizard
 
#19 ·
Can't say it any better on the speaker placement. I never thought it's that critical until I was talking to Scott3886 a while back. It was amazingly different, I just don't feel comfortable to make suggestion. I started out with equilateral Triangle with the two speaker and me forming the triangle. Make sure the speakers are away from the wall, then move it a little at a time, turning the speaker a little at a time. What ended up is not exactly equilateral triangle, but it's a good starting point.



Someone here gave me some sort of dimension calculation, should ask about this here. Strange thing is turning the speakers to face directly to me does NOT give the best sound, one speaker has to be a little off. That's when I found the sound panel lost the effect and I put it away. Don't jump into spending a lot of money on panels, experiment on speaker placements first. It really made a big difference for me.
 
#21 ·
.... Strange thing is turning the speakers to face directly to me does NOT give the best sound, one speaker has to be a little off. ....
The Angel or Toe-In of of the speakers is variable from speaker to speakers. Some perform better when they are angled toward the listener, some are better when facing straight forward. This seems to apply primarily to Highs. If the speakers are sounding a bit bright, face them straight forward to soften it a bit.

High frequencies tend to beam, that is to project in a narrow beam, the bean or arc becoming increasingly more narrow as the frequencies go up.

However, if we assume an arc or fan-out of 15° (±7.5°), at a distance of 10ft, that is an arc of prime sound is 2.7 feet. Most Tweeters are tested at 15° off the Center Line. This produces a slight but generally not significant attenuation. They are also tested at 30° off the Center Line, where attenuation is more noticeable. However, in my case, I'm only 7.5° of the Center Line, which means I'm still pretty much in the prime working span of the tweeter.

To estimate the Fan-Out at a specific distance for any tweeter, simply multiply the distance by the TAN of the selected Angle. And make a distinction between the Full Fan-Out and Off the Center Line. In my case, the full fan is 15°, but off the Center Line is 7.5°. If using off the center line, to get the Full Fan-Out double the number.

Fo = D x TAN(a)



Steve/bluewizard
 
#20 ·
The B&W 702 S2 sounds great in a demo room with a lot of other speakers, but after listening to them for 10-15 minutes I could already tell that they'd possibly be fatiguing. Personally, I wouldn't make a lot of expensive "room corrections" just to get those speakers tamed. A fatiguing speaker will always be fatiguing IMO.

The frequency response of 46Hz - 28kHz ±3dB is not great for such a tower speaker (on the low end). How do 3, 6.5" woofers in a tower enclosure only hit 46Hz at -3db? They seem geared more toward HT than 2-channel.
 
#22 ·
I will check out the wiring again and work on the speaker placement.

Blue & Alan, I really appreciate the thought you put into my problem!

As for what I'm not hearing is a crispness and defined notes as if you was watching someone playing right in front of you. The "sound stage" is somewhat there but weak. I find myself trying real hard to like it but the highs seem to overwhelm the details of the lower frequencies and my ear fatigue is very noticeable.

As I said in an earlier post, the 35" high counter runs the length of the front of the room and is approx. 30" deep. So, behind the towers the counter sits 24" away and the wall is stepped back to 54" away. Not sure if this is big problem or not but the counter can not be moved. I'm in the middle of carpeting other rooms in the house (what a mess...it's like moving) but will jump on this as soon as I can.
 
#23 · (Edited)
I will check out the wiring again and work on the speaker placement.

Blue & Alan, I really appreciate the thought you put into my problem!

As for what I'm not hearing is a crispness and defined notes as if you was watching someone playing right in front of you. The "sound stage" is somewhat there but weak. I find myself trying real hard to like it but the highs seem to overwhelm the details of the lower frequencies and my ear fatigue is very noticeable.

As I said in an earlier post, the 35" high counter runs the length of the front of the room and is approx. 30" deep. So, behind the towers the counter sits 24" away and the wall is stepped back to 54" away. Not sure if this is big problem or not but the counter can not be moved. I'm in the middle of carpeting other rooms in the house (what a mess...it's like moving) but will jump on this as soon as I can.

That's the very thing I got quite an improvement with the speaker placement and angle. Of cause my experience only applies to my speakers, but worth a try. With my right placement, I can literally hear the singers in front of me, a little in front of the plane of the speaker. It's just sweet.


I remember just two days ago, I felt the sound is a little off, the sound stage was less. I checked, my big boss moved the left speaker a little farther and turn the speaker slightly because it blocked the tv a little. I moved it back and everything is A OK again. It's that critical, she never told me, I just heard the change and I have to move it back. I am talking about 2" farther and slight change of the angle!!!! It's that sensitive.


Until you exhaust the placement experiment, don't even spend a penny just yet. Don't quote me on this, My experience and from what I read, all the room treatment are more effective on the bass or lower frequency, if you are complaining about the high is fatigue, I am not sure those room treatment can get you there. But, what do I know on this.


Yes, check the wiring. I thought I knew better, one time when I was testing amps with people, it just did not sound as good, NOBODY realize the problem. I use bi-wiring, that is I have separate speaker cables to drive the woofer and separate cable driving the mid/tweeter. I had the woofer wired correctly, but mid/tweeter was off phase. It really not as obvious as people think. The most obvious of off phase is the bass, if the bass is correct, it's a lot harder to tell. It just didn't sound as good.
 
#25 ·
Stereophile's John Atkinson had this to say about your B&W's measured performance (link below): "...these graphs suggest that experimenting with speaker toe-in and the listener's ear height will be necessary to get the most neutral treble balance from this speaker."

Indeed, as already stated in this thread, experiment first with positioning to find out if you can achieve an enjoyable sound quality.

https://www.stereophile.com/content/bowers-wilkins-702-s2-loudspeaker
 
#34 ·
Having read Mr. Atkinson's reviews over the years let me translate the quote above. First some general help with translations:

o In review - in normal words

o Uniformly excellent - excellent

o Excellent, but a small item - very good at most

o Consistent or uniform or good engineering - average

o Overall good, but his concerned me - avoid

o More than one problem noted, or takes care in setup, experimentation required, etc. - run, don't wank away - This appears to be where the 702 S2 falls...


OK, why is that?

o Non-uniform response on axis, which is the most important factor in speakers according to Floyd Toole. This means don't buy the speaker. There are better choices. This isn't a family member or a losing local sports team. Walk away...

o Very uneven response off axis. It would be necessary to a absorb all of the off axis response. This is unacceptable.


What to buy?

o Revel make some excellent speakers starting with the F208. Used Salon2's can often be had for only an arm, not an arm and a leg.

o Most speakers, higher end Revels excepted, tend to be uneven off axis at say 45 degrees at least in the horizontal plane. This is due to a change in the dispersion characteristics between woofer (or mid-range) and tweeter. Two-way speakers (think bookshelf's) are often particularly bad. Speakers with a 1st or 2nd order crossover to the tweeter, which results in the crossover to the tweeter being at a high frequency, accentuate this issue. The elevated response from the tweeter off axis is in the frequency range where the ear is most sensitive adds to the problem. In turn the response from the mid-range or woofer has fallen off axis before the crossover to the tweeter.

The off-axis response of the 702 S2 in Fig. 5 of the Stereophile piece clearly shows this effect. This is likely the most common reason why many speakers sound harsh.

3-way speakers with 4th order crossovers are usually more expensive, but have some inherent advantages. Treatment of the side walls at reflection points with 4" of fiberglass would be a good idea for far too many speakers.
 
#26 ·
I purchased a very expensive set of speakers years ago,

After the "honeymoon phase" was over (a few days) I detected something "off" in the midrange--wondered if it was room acoustics, setup etc. Just in any math problem, get rid of the unknowns so I set up my pair of speakers outside on a calm day for a listen. They did sound better outside although the bass was weaker (of course) I really, really wanted it to be a room issue--because I spent big bucks but... that issue with the midrange was till there. I had another pair of much smaller speakers that I liked, took them outside and they sounded better also. Logic dictated that I could use more room treatments and positioning--and a touch of EQ but my expensive towers would never sound right. Put the speakers back in the dwelling and although I was in denial, it became obvious my super speakers did not do it for me. I ended up selling them a week or two later-llive and learn. Over the years, I've listened to all of my speakerz outside either on a table or on the ground to listen for anything weird. I'd try EQ which worked for some speakers but others not so much. Then I move them in a room so it can destroy the response as rooms do but I save a ton of time knowing what I am fighting.

This works very well when evaluating subwoofers--the room will drive you nuts! If it is eneven outside, forgot about it when throwing it in a room! EQ will help you with some things, give it a shot outside and get desperate and actually measure it! ;) Also, be aware that subwoofers actually get better with more of them--don't work that way for mains but grab the advantages you can first.

If you are the type that slaps speakers down in some random location, don't try moving them around, forget about measuring--they should always sound good no matter what--acoustics don't work that way. If you learn about acoustics, learn about speaker setup and such--that will solve most of your problems. Some rooms are so poor acoustically (like a high school gym or rooms with a wall of windows) you really are screwed at the start because of room acoustics. If you have a working knowledge of acoustics, that will save a ton of time by not using acoustically poor rooms (perfect squares/cubes or highly reflective) Then the problem becomes standing waves, floor bounce/ceiling bounce, wall splash and so on as typical. If you listen to your speakers outside first, anything that you find new and annoying is the rroom. Changing amps, speaker wire, DACs or power outlets won't fix the problem if it is speaker, setup or room related--sure wich it would! Alas, no magic box and there is no app for that but that is what makes it fun! This stupid thing we do is fun--right? :D

Sure hope it is warm enough for your weekend take the speakers outside listening test--hope the weather helps you out in your quest. Good luck! :)
 
#29 ·
Alas, no magic box and there is no app for that but that is what makes it fun! This stupid thing we do is fun--right? :D

Sure hope it is warm enough for your weekend take the speakers outside listening test--hope the weather helps you out in your quest. Good luck! :)
Lol, I wish.......I have a few simple dreams before my big check-out-of-life and just sitting back listening to the sound track, on a decent musical level, of my life, is one.

Alex F. The link you referenced was a major reason for before choosing the 702's. They sounded great in the demo room, was in my price range and I was sold.

alan0354, I will give it a shot if all else fails....like you said, nothing to lose.

Thanks to everyone for the help and thoughts!
 
#27 ·
OK, this is a wild swing if all else failed. I had experimented when I was working inside the speaker and the tweeter was getting a little loud. I hide a little cloth in front of the tweeter, something that is porous. The idea is like grill cloth, people kept removing the grill in front of the speaker because it just muffles the treble very slightly. In this case, if the tweeter still loud, what do you have to lose? I experimented a little, it seems to work. Just try and see.....Hopefully it's free, just find some scraps.
 
#28 ·
One thing not discussed: If the B&Ws were purchased recently and still can be returned to the dealer for a refund or exchange.
 
#35 ·
As a hifi amp designer, I am not sure recapping is what it's hyped to be. Few years ago when I first got into designing amps, I bought a Nakamichi Stasis PA-7 designed by famous Nelson Pass. It's like 30+ years old, I took pictures of the noise and ripple of the big filter caps and asked on DIYaudio forum and confirmed that it's time to change those caps. I spent $120 buying the new caps and changed them myself. NOT A DAMN OF A DIFFERENCE IN THE SOUND.


My Acurus has been in constant use (5+hrs/day) for 16 years before I retired it. Sounded as good the last day as the first day. Far as I concern, I look at those caps, if it is not leaking or bulging out on the top, I would not be dying to change them.


As an engineer for decades, if it's not broken, don't fix it!!!


One question I need to ask Timestoo, what speaker cable you use. You have very nice amp and speakers, I hope you use something better than just any 12 gauge wires. It's my opinion from engineering and practical point of view the speaker cables is AS IMPORTANT as the speakers and amp. The system is only as good as the weakest link of the system. I am not the one that push for more expensive the better. I don't believe in spending a lot of money on those RCA interconnect, but I do pay a lot of attention on the speaker cable. I am born cheap, I build my own speaker cables from engineering point of view and I got tremendous result.
 
#36 ·
This is what I have and noticed it is only 14 AWG....

AudioQuest X-2 bulk speaker cable - 14 AWG

The negative thoughts and comments have me tossing and turning at night. Why would such a great MFG as B & W design and market such a speaker as what is being described?

I'm trying to get things finished here so I can experiment with positioning.
 
#39 ·
i own some klipsch towers that can be harsh. even with eq like -5 treble they can still be harsh. its more than measurements or positioning that cause ear fatigue. with all that I can still get my klipsch to sound fantastic, just at very reduced volumes.
 
#42 ·
So far, quite a few people had given suggestion, what have you tried so far and how did that work out?


This is a trial and error type of thing, you need to try the suggestions as long as you don't have to spend money.
 
#44 ·
Alan, Today is the last rooms getting carpet installed. We have more stuff than needed and my back pain proves it. It will be a week before "my room" gets attention.

I have an Anthem MRX 720 driving the theater side. I really wanted to use the Classe but do you think the MRX would be better because I can set the values going to the 702's?
 
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