MB Quart QL S830's lacking bass

[nightflier]

I have been listening to a newly acquired pair of MB Quart QL S830's that are connected to a HK3480 amplifier (150W / channel into 4 ohms). I am using a standard Onkyo DVD changer and am using the sub outputs to power a Monitor Audio sub. I've kept everything as simple as possible.

Now I've had a lot of speakers in my home and must say that I expected more out of the MB Quarts. While the speakers are fantastic in the mid and upper frequencies and the sub is able to pick up the very low frequencies w/o problems, I seem to be hearing a hole in the mid-bass as if the speakers aren't able to meet the sub. The speakers should be able to reach down to 33 Hz comfortably and I have the sub set to cross over at ~50Hz., but I still feel like there is a whole octave missing there. If I remove the sub out of the equation, the speakers just sound like they have very little bass at all.

I am using Audio Quest Sidewinder interconnects and I am using 16 gauge Radio Shack speaker wire crimped with generic banana plugs. I have some AQ bedrock speaker wire on order, but is that really the cause of the problem? I don't have any other 4 ohm speakers on hand, so I can only compare it to several pairs of 8 ohm speakers I have, and while none of them sound as good in the mids and upper range, they all have better bass response.

I prefer a warm sounding speaker, so these MB Quarts are becoming a bit of a dissapointment. I have not opened them up and looked inside, but before I do that, I wanted to post my question to the forum to see if I was missing something. I don't have much other equipment or wire to swap out right now, so I can't try too many things. So to recap:

- Am I using the wrong speaker wire?
- Is this the typical character of these speakers?
- Am I connecting something wrong?
- Is the HK3480 the problem?

Thanks.

[topspeed]

It's likely your room acoustics, it could be your amplifier, and it sure ain't your interconnects or wires (although 16g is pretty thin). Ohms have nothing to do with bass response so don't worry about that either. Your HK may not be a good synergistic match with the MB's, but the only way to tell is by switching it out with another amp and seeing what happens. BTW, even though MB's spec's rate the 830's to 33hz, they don't state whether this is in-room, anachoic, down -3dB or -6dB. In other words, don't take it as gospel that they will play this low in your room.

You need to start playing with the positioning of the speakers and get a spl meter and test disc to start measuring your in-room response. Every speaker will interact with a given room differently. Try placing them closer to the corners to get some reinforcement, but don't make them equidistant from the back and side walls. Do a search for Richard Greene on this forum and you'll learn everything you ever wanted to know about room acoustics, nodes, etc. The info is invaluable and required reading for anyone remotely interested in optimum performance.

Hope this helps.

[abstracta]

Can I be honest?

According to MB's home page, that speaker goes from 33Hz - 32kHz with two poly 6.5 drivers and a metal dome tweeter.

Sorry, but that's not happening with those drivers. I thought only Definitive Tech exagerated that much, but I guess MB's guilty as well. With a sensitivity of 87db I'm also scratching my head because that usually means the mid-woofers are running in parallel, or something isn't handing it's frequency range correctly so everything else was padded down to make up for it. Call it a 3 way speaker that really should have stayed a 2-way.

By looking at the driver config and ignoring the marketing I'd guess these speakers are good down to about 60-70 before they get really inefficient, resulting in that big hole. When you say you think there's a whole octave missing, you might be pretty darn close.

Bump the sub crossover up, and/or experiment with moving your sub around till it finds a spot where it can smooth out that big hole a bit better.

[nightflier]

Can I be honest?

OK, OK, I wasn't looking for an MB Quart bashing, here. I did a lot of research on these speakers and while the specs are not listed on their website, they are supposed to be fully capable to 33Hz. +/-3dB, in-room. I purchased these speakers because they were made in Germany (where typically warm speakers are prefered) and have very highly regarded tweeters that are capable of much higher freqencies than your typical CC or GG speaker; I wanted something to test the higher resolutions of SACD. I am upgrading my system and am awaiting better equipment that should be here in the next month or so (B&K Preamp, PS Audio amp, AudioQuest cables, Phillips SACD).

Unfortunately I sold most of what I had before I could test the speakers and all I have left is the HK3480 receiver and some extra speakers. In the mean-time I wanted to start listening to some music and was rather surprised at the bass-response of these speakers. Specifically:

- While the room acoustics may be a factor, then it should also be a factor with my 8 ohm speakers, but it isn't.

- If I am only running 12' of cable to each speaker, is 16GA wire really too thin?

- Top, what did you mean by the "HK may not be a good synergistic match with the MB's"?

[topspeed]

While the room acoustics may be a factor, then it should also be a factor with my 8 ohm speakers, but it isn't.I beg to differ. As I mentioned, every speaker will interact with a given room differently. Ohms have nothing to do with it. After speakers, room acoustics have a more profound affect on sound than anything else. Eliminate both of these as the problems before you start looking at your front end.


- If I am only running 12' of cable to each speaker, is 16GA wire really too thin? There was a great graph that showed the losses over certain distances with specific wire gauges. Do a search here and you should be able to find it. The bottom line is that the lower the gauge, the safer you are. Whether or not it's discernable is a whole 'nother debate.


- Top, what did you mean by the "HK may not be a good synergistic match with the MB's"?System synergy is the "black art" of audio. What I mean is that you can take two pieces of equipment that both have steller specs, put them together and end up with horrible sound. Why? Who knows, but it happens all the time. Some things simply don't like to play together. To simplify, you can go one brand all the way, such as RGA's beloved Audio Note. AN TT to an AN integrated thru AN speakers. This approach makes sense as you know the pieces were designed and voiced to work with each other. However, what happens if you think ClearAudio makes a better TT than AN? Do you compromise for the sake of system synergy?

Unfortunately, the only way to find system synergy is through trial and error. When looking for an amp, I tried so many freakin' brands it took me 6 months! Thank goodness for very understanding dealers and friends who loaned me their gear. The good news is that when the pieces fit together correctly, it's readily apparent.

[abstracta]

OK, OK, I wasn't looking for an MB Quart bashing, here.

Not bashing MB Quart. I'm bashing their marketing dept for relasing such absurd specs. You simply aren't going to get decent bass response from that driver/speaker by looking at it's config, and/or there's a hidden 8"driver in the side. Does the speaker sound fine other than the bass problem? You tell me.


they are supposed to be fully capable to 33Hz. +/-3dB, in-room.

Yeah....Maybe at -12/18 db down.....

I noticed your MB's are also front ported, which typically results in 'drier', more clinical bass response over rear ports which tend to get a lot of rear wall boosting. Personally I prefer front ported designs because they are cleaner, but unless you get them real close to a room boundry they can sound rather flat in the lower bass *if* you are working with small drivers, and you are. I'm also guessing you have them in either a large room, or fairly distant from the walls. By looking at this speaker I'm guessing it would have more 'weight' in the bass region if it were in a smaller room near the corners.


MB can make all they claims they want about their tweeter hitting 33khz, but that poly 6.5" driver isn't going to be very efficient below 50hz, and the fact the speakers are 87db efficient kind of tells you something.

So, I still suggest fixing the problem by moving your sub around and tweaking the X-over point a bit. The other comments I'm seeing here about speaker wire and ohm ratings are almost hysterical, but I think you are figuring that out.

[nightflier]

I had some time to move the room around last night. It was originally set up length-wise which was a problem because I had the dining area (ie. open area) to my left. I now have the speakers along the long wall, with the dining area behind the sitting position. I also went to RS and built some new 14 gauge speaker cables because I needed about 20 extra feet to reach the far corner. The speakers are toe'd in a little but about 20" away from the side and rear walls (force of habbit; I didn't think about these being front ported so I'll have to change that tonight).

The sub was removed from the system and I changed out the AQ cables for borrowed Monster ones because the AQ's were too short. For comparison I am using Polk Audio RT600i's, which have a flared, down-firing port and have just the best bass I ever found in a budget speaker (bought for $600 new, but wish I would have bought the 800's instead). Despite the bass, they leave a lot to be desired in the mids and aren't engaging in any other way. Like so many budget speakers, they are "just there."

I had about one hour left for listening so I played some jazz (Coltrane, Brubeck) and vocals (Brightman and McKinnit). I must say that the more I listen to the Quarts the more I like the exquisite details in the mids and highs. I can place the instruments exactly where I believe the recording engineers intended them to be. There is also a tremendous amount of spaciality where I can hear (or at least I think I can hear) that certain sounds in the band are behind others. That said, they don't have the upper & mid bass I remember hearing when I auditioned other speakers (the Axiom M50s, PSB 4T, Dynaudio 72s, and even the tiny Polk LSi15s stand out as most memorable). I know the Danes are in a different league, here, but I've just never heard anything that well balanced in my home, and I am still looking for a less expensive alternative.

So I was hoping to get some of this performance from the Quarts, but I think this isn't going to be the case when it comes to the bass response. I suppose in my current budget setup, both speaker sets offer something the other lacks. Also, the Polks need to be as far from the walls as possible, so using all four speakers wouldn't really work either, especially since there is no way to adjust the volume seperately for the B speakers. Besides, I'm trying to sell them. I suppose I should wait for the amp to arrive, since the HK3480 has preamp outs. I'm borrowing a PS Audio HCA-2, but I don't know if it will add that lower-mid and upper bass that isn't there now. Any opinions on this?

I will move the Quarts closer to the corners tonight (I'll be scoring some WAF points for that anyhow). I suppose, if I could find a pair of speakers that would complement the Quarts by excelling in the upper bass, that would be ideal. Someone posted a pair of Dynaudio Contours on eBay that would fit the bill but they will likely be priced out of my league by the time they sell. Any other speaker recommendations?

[topspeed]

I will move the Quarts closer to the corners tonight (I'll be scoring some WAF points for that anyhow).LOL! :D Well that's always a good thing!

When you move them, just make sure they aren't equidistant from the back and side walls otherwise you'll encounter out-of phase waves that will cancel each other out and leave the response thin. Read this to understand why. (http://forums.audioreview.com/showthread.php?t=2461)

As for your amp question, my guess is that you will hear a difference. How big? I dunno. When going from a Denon 3803 to the HCA2, the improvement in bass response on my B&W's was profound. I actually checked to see if the sub was still on (it wasn't). No joke. That's one of the HCA2's trademark strengths, so you may find the MB's to be exactly what you were looking for after all.

For speaker recommendations, there's a "What's the best speaker?" thread about every other hour here. Just do a little research for more opinions than you'll ever need :).

Hope this helps.

[Kursun]

that poly 6.5" driver isn't going to be very efficient below 50hz, and the fact the speakers are 87db efficient kind of tells you something.
I don't think your theory, less efficient speakers being not efficient at bass frequencies, is correct.
On the contrary,
You can manufacture a highly efficient woofer (http://forums.audioreview.com/editpost.php#) by putting a powerful magnet at the back. It will be more efficient but its cone's motion will be highly damped, producing thin sound and rolling down earlier than a woofer with an optimum magnet. Such a speaker will resonate more severely at its resonance frequency with a higher Q and will typically produce "one-note" bass.

Whenever I see a woofer with higher than usual sensitivity I wonder if it has been achieved at the expense of low frequency extension.
(I'm an amateur speaker builder. http://www.geocities.com/rakursun/loudspeaker.html )

[nightflier]

For speaker recommendations, there's a "What's the best speaker?" thread about every other hour here. Just do a little research for more opinions than you'll ever need :).

My criteria for speakers is pretty narrow:

- Preferably bookshelf
- 4 ohm & lower sensitivity (86-88 dB to match the towers)
- not at all bright
- good bass extension
- mid-fi (dynaudio audience level)

and just to add a little spice to it all:

- under $1000

Now I know I could probably find a really low-quality pioneer speaker to do that, but I would still like something that can tango with the Quarts. Since the HCA-2 won't have independent channel volumes (actually it only has one set of speaker hookups), I need to match the Quarts as best as possible output-wise, but with added bass to make up for their shorcomings.

Turning up the cross-over on the sub is not an option here, either. The sound then becomes too directional, and I really want to avoid that.

[nightflier]

(I'm an amateur speaker builder.

Kur,

What's your opinion of the Quart's 6" woofers? I've read that they are highly rated in the auto market, but they're rather new to the home audio crowd.

[topspeed]

Correct me if I'm misunderstanding you, but you want to run two sets of mains?? This configuration can't possibly work. It's an acoustical nightmare rife with cancellation issues.

My advice is that if you can't get the Quarts to satisfy you even after you've addressed room acoustics and the front end, you're simply going to have to audiogon them and start all over. You'll have a bigger budget (not that you can't find excellent speakers for under $1K) which will give you more options.

I'm also confused as to why you keep bringing up ohms. All that tells you is the resistive load they present to an amplifier and even then, ohms swing all over the place depending on the frequency. As you know, the higher the number, the easier the load so if you're going to try to drive four speakers off one stereo amp, the less resistive the better. Thankfully, the HCA2 is load invariant, but it's still better to not push your luck.

A lot of good recommendations were made in this thread. (http://forums.audioreview.com/showthread.php?t=10906)

Hope this helps.

[Geoffcin]

- Top, what did you mean by the "HK may not be a good synergistic match with the MB's"?

Although your receiver is rated to 4 ohms, and the speakers are nominally 4 ohms, the bass may dip to 3 ohms or even LESS! If this is the case the receiver's amp might starve those frequancys for current. This would make the speakers appear bass shy, but if you hooked them up to an amp capable of delivering curring into low impedance loads you might be shocked.

You should try moving the speaker back toward the wall to pick up some room gain in the mean time.

A speaker with dual high excursion 6.5" woofers should be able to make good bass into the low 30's. I've heard it, it is very possible.

[nightflier]

Correct me if I'm misunderstanding you, but you want to run two sets of mains?? This configuration can't possibly work. It's an acoustical nightmare rife with cancellation issues.

I was referring to an amp I had borrowed from a friend a while back, a Parasound 2125 (I think), that had four speaker terminals for two sets of speakers and an A/B switch on the front. Another solution is to run two amps bridged together with regular RCA cables. I haven't tried this, so I can't say how well it works.

Now I don't know if that's going to be an acoustical nightmare. I've always only run a single pair of speakers from the amps I've auditioned (even the Parasound). If you say that will sound terrible, then that's something I need to know.


I'm also confused as to why you keep bringing up ohms. All that tells you is the resistive load they present to an amplifier and even then, ohms swing all over the place depending on the frequency. As you know, the higher the number, the easier the load so if you're going to try to drive four speakers off one stereo amp.

I was only bringing up the ohms & sensitivity because it will affect volume. If I was going to use an amp like the Parasound, I would not want to have two sets of speakers playing at a different volume, that's all. Also, Parasound does not recommend driving 4 and 8 ohm speakers together; their amp will support it, but it's not recommended.

So provided that having four speakers adequately driven with good amps is not an acoustical nightmare, is there a bookshelf speaker out there that can fill in the bass a little? I can't really do that with another pair of Quart bookshelves because they will not fill in the bass. If there are no other speakers out there for this purpose, then you're probably right that I made the wrong decision in buying these Quarts. That said, I really like the clarity and spaciality of these speakers. It's been a long time since I heard that in my living room.

[nightflier]

My advice is that if you can't get the Quarts to satisfy you even after you've addressed room acoustics and the front end, you're simply going to have to audiogon them and start all over.

Audiogoning is a verb?

Not so fast.... I hooked up the B&K Reference 4420 amp and everything is better now: deep rich bass from a whopping 350W of power. I've also tried a PS Audio HCA-2, but it still needs to burn in for a few days. For now, the B&K is driving these speakers and I'll have more to say about these two amps after a couple of weeks. Currently I'm using the HK3480 as a pre-amp until my B&K pre comes in. LSS, the HK, while being a great receiver, really isn't designed for low sensitivity 4 ohm speakers. I have to admit, this is the first real weakness I have found in this receiver (you'd think HK would know how to drive fellow Geh'man-speakers).

I'm also comparing the Quarts to a pair of studio monitors and the two are very close. I think the monitors suffer somewhat from not being powered by a large amp (they are active monitors), but even in the mids they are only slightly better than the Quarts, which is saying a lot. While being just a tad less detailed than the monitors, they have more richness and warmth and with the B&K, they have ample bass. Regarding that bass extension, it's true that those are not 10" woofers, but for what they do deliver, it is very well done. To my ears, they are very transparent and I quickly forget that they are there (although moving them deep into the corners of the room may have something to do with that too). And when I finally pluged the sub back in to complete the bass, the sound was astoundingly good. Coltrane never sounded so full and rich and even Mahler's 5th sounded better than ever.

So, yes, the Quarts are hard to drive (as my checkbook quickly found out), but they are phenominal speakers when you get them set up in the right system. So at the risk of sounding like a president, any Quart naysayers out there, bring it on...

[m500]

Audiogoning is a verb?

Not so fast.... I hooked up the B&K Reference 4420 amp and everything is better now: deep rich bass from a whopping 350W of power. I've also tried a PS Audio HCA-2, but it still needs to burn in for a few days. For now, the B&K is driving these speakers and I'll have more to say about these two amps after a couple of weeks. Currently I'm using the HK3480 as a pre-amp until my B&K pre comes in. LSS, the HK, while being a great receiver, really isn't designed for low sensitivity 4 ohm speakers. I have to admit, this is the first real weakness I have found in this receiver (you'd think HK would know how to drive fellow Geh'man-speakers).

I'm also comparing the Quarts to a pair of studio monitors and the two are very close. I think the monitors suffer somewhat from not being powered by a large amp (they are active monitors), but even in the mids they are only slightly better than the Quarts, which is saying a lot. While being just a tad less detailed than the monitors, they have more richness and warmth and with the B&K, they have ample bass. Regarding that bass extension, it's true that those are not 10" woofers, but for what they do deliver, it is very well done. To my ears, they are very transparent and I quickly forget that they are there (although moving them deep into the corners of the room may have something to do with that too). And when I finally pluged the sub back in to complete the bass, the sound was astoundingly good. Coltrane never sounded so full and rich and even Mahler's 5th sounded better than ever.

So, yes, the Quarts are hard to drive (as my checkbook quickly found out), but they are phenominal speakers when you get them set up in the right system. So at the risk of sounding like a president, any Quart naysayers out there, bring it on...


I also have a set of new MB Q S830 from 2 month ago. Found out the hard way just like you did. Have to spend a lot more to get my NAD352 to drive my Quarts. Move my Brand new Yamaha RX-V650 to karaoke room since it doesn't have enough juice to powered my Quarts and I can't returned it due to I bought it from auction. My Quarts is now starting to break-in with some nice bass coming out of it. I'm thinking about getting a sub as well but only the best can acommendate my Quarts. So, it'll be sometime before I pick up a SVS or HSU mid line. I really don't want to settle for the entry level SVS or HSU as I know that I will grow tired of it quick. I'm trying very hard to not start impulse buying until I have enough free funds. Maybe I should take my kids out of summer school and use the fund for my new SUB. HEHE.

[nightflier]

I really don't want to settle for the entry level SVS or HSU as I know that I will grow tired of it quick. I'm trying very hard to not start impulse buying until I have enough free funds. Maybe I should take my kids out of summer school and use the fund for my new SUB. HEHE.

If you have an extra receiver or amp laying around (an old NAD will do just fine), you might want to consider the passive SVS 25-31CS. At $379, it's a steal. It is rated to 25 Hz, but it doesn't really have a major drop-off until it reaches 18Hz. A friend of mine was balking at paying $600 for a cube sub a couple of years ago, so he bought this model since he had an old Technics receiver that he wasn't using. He liked it so much he bought a second one two months later and his HT setup sounds extremely good now (even with that old Technics powering the subs).


(That said, a good amp will bring out a lot of bass out of the Quarts, more than you may need.)

[topspeed]

(you'd think HK would know how to drive fellow Geh'man-speakers). HK is North American. IIRC, Harman Int'l is Canadian.


So, yes, the Quarts are hard to drive (as my checkbook quickly found out), but they are phenominal speakers when you get them set up in the right system. So at the risk of sounding like a president, any Quart naysayers out there, bring it on...
I don't think there is such a thing as specific speaker naysayers (except for Bose, and that's just because they are overpriced). Speakers are purely subjective so they will either work for you or not. It sounds like the MB work for you now that they are properly driven. Congrats and enjoy the music!

[nightflier]

HK is North American. IIRC, Harman Int'l is Canadian.

I always thought they were German. I guess you learn something new everyday (in my case, every hour or so...)
:p