Underpowered?


Hi guys.  Newbie here asking for advice. 

I recently purchased a pair of B&W 702 Signature (8Ω, 30-300W, 90 dB) to replace my old faithful 683s (8Ω, 20-200W, 90 dB).  I am running them with a McIntosh MA252 (100W into 8Ω, 160W into 4Ω).  I purchased them thinking they would complete my end-game system.  However, my excitement turned into disappointment when I realized the lows were somewhat lacking.  For all their faults, the 683s had a great dynamic low kick (no sub) that I was looking to take one step further.  Unsurprisingly, the highs and mids on the 702s were indeed more detailed and separation was clearer, but I couldn't get over the uninspiring lows.  I found myself listening at higher volumes chasing for that bass oomph.  Neither playing with the EQ at the source nor the amp was satisfactory.  So, I did the research that perhaps I should've done before purchasing the 702s and found out they are quite power hungry despite the specs being similar to the 683s.  I emailed B&W and McIntosh and they agreed the amp is probably underpowered for the 702s.  B&W described the sound of an underpowered speaker as one lacking low response and details, which is spot on. McIntosh suggested the MA352 (200W into 8Ω, 320W into 4Ω).

Of note, I love the MA252 and really wish there was a way to make this work.  I don't need a DAC/streamer/etc so I'm happy to put all my money on better sound vs tech features.  But I also think the speakers sound amazing even when somewhat underpowered and I'm considering upgrading to a MA352, Michi X3, Hegel 390.  Another option could be to get a sub? But I feel that would defeat the purpose of having a 3way standing speaker and then I might as well get a pair of bookshelf speakers (805 D4s, LS50 metas?).

So what do you guys think? Is it normal for a speaker that's rated 30-300W to be underpowered with a 100W amp?? What would you do:

  1. Sell the 702s and look for a better match for my MA252?

  2. Upgrade the MA252 (MA352? Michi X3? NAD 33?)?

  3. Get a subwoofer?

I would really appreciate your thoughts/advice!

dridel

@dridel Congratulations on your new speakers! 

 

I grappled with a similar problem over the past three years. Having moved to a new house my B&W801M S2s didn't sound the way they used to. I upgraded the XOs, then the preamp. Had my Krell KSA-250 recapped. All to no avail: the bottom octave was still AWOL. Then I had a lightbulb moment: maybe the problem was the room. I lugged one of my BK subs downstairs and hooked it up. Result! The bass was back.

 

Ordered two new subs and dialled them in. Now the system sounds better than it ever has.

 

I reckon your room doesn't play nice with the new 702s. They aren't speakers that are hugely difficult to drive, I don't think your MA252 is the problem and a new amp is not going to fix things. If changing the 702s' room placement doesn't improve their bass response and apart from that you like they way they sound, the quickest, easiest, and most satisfying way to address that issue would be to install two subs. Been there, done that...

 

REL (and BK) subs feature a high level connection which I prefer for a two channel connection. You do not hear my subs, you only feel their "foundation", along with a wider, deeper sound stage. A friend who popped in for a listen didn't even notice them sitting in the background as the music was playing...

 

Good luck!

Adding subs will be my number one ☝️ choice or buy Class D amp to bi-amp

Class D for lows and McIntosh for highs 

Tricky situation and logical way out not always a help. If you was satisfied with your three way sound signature adding subs could not be solution. I would go with amp or speakers replacement. 

The first thing to do is if you have standard wires, you will need a jumper if there is 4 posts and you have 2 wires to connect( plus and minus)

Second, play some music walk around the room.  Do you hear boomy bass in some places and none in others.  Go to the corners, is it boomy there?  If you hear this then you should try moving your speakers around.  I point them right at me and sit back the same distance as the speakers sit apart.  Some speakers only need to be tilted in slightly.

Third, even if the room is not too bad for acoustics, a sub is a real helper here.  Very few speakers go down low enough  in the bass.  Especially, since you said you liked bass.  But you may find once you fix positioning and room problems your speakers are OK.  Try sitting a sub right beside a speaker.  Point it toward you or the wall.  If you have a second sub put it along the wall by you. 

Fourth, you are used to the B&W sound so I would not ditch these speakers...yet.  Same with the amp.  Depends on how loud you like your music.  But amp replacement is after you try a sub.  A powered sub has it's own amp and bass takes the most power, so your 252 may be enough.  Also, less excusion of the woofers reduces distortion of midrange frequencies.

Don't feel bad, they always say build your system around your speakers.  :)

 

I ran into a very similar thing but I knew that lack of power had nothing to disclose with it. Started out with what turned out to be an amazing thing I bought a pair of furutech wall outlet plugs all of a sudden I had some base out of my Levinson 33s. I then put a set of furutech plugs on the end of the captive power cords better again. Then I fooled around with room placement. Each time I got more base. Also thinking of you have two sets of binding post on the back of the speaker's it is time to replace the flat tin jumper bars and go to a true jumper. Easy to get that  before you buy just try it with some copper wire of a heavy gauge of you think it does a bunch then get a good one. Also I bought a cable break-in ma home that was made by siltech that made a huge difference on every piece of wire on the system. The tonal range got bigger at bother ends. It didn't matter if the wire had been used regularly for twenty years. The range got bigger the sound fuller etc. When you setup the room I personally like the speakers setup on odds vs evens. On evens you tend to accentuate mid bass. A real rock and roll set up the speakers a quarter of the way into the room and a sixth of the way from the side of the room and the chair a quarter of the way into the room from the back wall. Personally I set the speakers a their of the way onto the room and a fifth for the side walls. I Then.make fine adjustment from either one of those places. Make sure the speaker s are level to each other  and they are at the exact same height.  Do you have spikes down to the floor? Did you change any placement of the gear? Different stands can make a huge difference as well. Personally I think your base is there you just have to find it. 

 

Regards