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

Reading all this discussion makes it all the more clear that the gear is as much an instrument in the music you listen to at home as anything that's recorded on a given disc. Talk about transparency or neutrality or specifications is kind of bunk. A stereo is a machine that makes the music sound better. 

can't believe it's not enough power unless you're in a monster size room. Systems have oomph if they're dynamically linear and that can be limited by a speaker with a lousy impedance load and/or an amp that can't handle the load. My gut feeling is it's the speakers.

That plot labeled “graph 5”  in the link looks like -5dB at 100Hz... and headed south.

 

Before you change equipment I too strongly recommend playing with speaker placement AND listening position. I too had this exact same issue when I got my floorstanders (Spendor D7.2) and thought a sub could fix it, it didn’t sound ‘better’, I could just hear an exaggerated boomy bass that was separate to the speakers. So I spent hours moving the speakers around and at the same time moving my listening position around. What you might have is a null where you are sat which is cancelling out the bass. If you find standing in different places gives you more bass, then there is bass in your setup, you just need to find the listening position coupled with speaker placement that is the bass sweet spot. I have the Hegel H390 and personally love it, the bass it produces has a wonderful tone that is addictive. I am not suggesting it is THE amp or that it will improve things, just that I’m a happy owner of one of the amps you mentioned.

Room treatments will help the bass response further but just make sure if you are going to use them you get something that will actually make a difference. For the lower frequencies it is all about the depth of the trap, thin traps will do nothing to slow down the lower frequency waves which can be cancelling each other out.

Finally once I had found my preferred speaker and listening position, I purchased a basic app called HouseCurve and that was a super cheap way to get some feedback on the in room frequency response. This app is in no way professional like REW, however it did give me the frequency ranges that I had bass dip in which I then boosted with parametric EQ and reduced slightly the upper frequency peaks. Together that massively balanced out the sound bringing the bass through even more. If the highs are dominant you’ll notice them more and reducing them slightly can bring through more bass perception.

My big takeaway is there is a lot you can do, which really is the fun of owning a system, the tweaking and trialing things. Simply replacing the amp may not bring any improvements if it’s actually the room and placement of speakers and seat that are the issue. Try all of the above first and if there are no improvements then you may need to upgrade. I’m from the UK and we tend to try and not run subs, your floorstanders will have enough bass and it is better (imo) to get it out of them rather than just over-boosting the bass with subs that aren’t integrated properly. I now don’t use a sub for music as my setup has it all following the work I carried out above, the sub only gets turned on for films and at this point only provides rumble.

@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