Flatback or Roundback?

[Jeremy Morgan]

I would be interested to know what the differences are between Flatback and Roundback (i.e. carved back) basses.

I understand that flatback basses are generally cheaper to make because they use less raw material & require less labour time in their construction (no carving/hollowing out required).

But what about the sonic differences? Which tend to produce a brighter/darker sound? Is one type more suitable for jazz or orchestral playing? How about sound projection? Player comfort? Is a roundback less prone to soundpost cracks?

I have only owned roundback basses up to now so only have experience on these, plus I realise that individual basses may behave differently to the agreed norm.

My searches on the forum haven't really helped to fully answer these questions so far, so I'd appreciate your comments.

[Chris Fitzgerald]

I prefer roundback basses. In my (admittedly limited) experience with flatbacks, they have a resonance to them that is compelling and powerful at first glance, but tends to sound unfocused to me once other instruments are playing - and I'm speaking in terms of my experience with jazz only here. Plus, as a seated player, I don't care for the way the bracing kills the vibrations that I normally feel through the back against my legs and belly.

[xwtb]

You're bound to be referrred to the work of Andrew Brown on the topic, which can be found at http://www.awbmusic.com/acoustics/

[Eric Hochberg]

Round backs are more trouble free than flatbacks that need to be rebuilt from time to time.

[larry]

Originally Posted by Chris Fitzgerald

I prefer roundback basses. In my (admittedly limited) experience with flatbacks, they have a resonance to them that is compelling and powerful at first glance, but tends to sound unfocused to me once other instruments are playing - and I'm speaking in terms of my experience with jazz only here. Plus, as a seated player, I don't care for the way the bracing kills the vibrations that I normally feel through the back against my legs and belly.

I have a flat-back hybrid Lascala (I know you have a roundback of the same). Man, I wish we could compare ours in the same room.

It's funny because I used to think mine sounded too focused - like I wanted a little more bloom or puff to it. I have listened to your recordings and I really get what you are saying. Your bass sounds very focused and it sounds great. I think that direct-ness in sound translates well to typical ensemble situations as you essentially said.

I was starting to get frustrated with my sound, so I took a different string direction and I fell in love again. (I took off the Oliv/Eudoxa combo and put on a full set of Belcantos). My Lascala has never sounded better. It has more puff to it now (which seems odd that I got it from going from gut core to steel), but it still cuts through the band.

Regarding the long-term problems - Arnold's hybrid seems the best of all worlds. My top and sides are carved, but the back is more durable ply. Arnold also has some unique bracing that is supposed to hold up better than other flatbacks.

[Chris Fitzgerald]

Originally Posted by larry

I have a flat-back hybrid Lascala (I know you have a roundback of the same). Man, I wish we could compare ours in the same room.

It's funny because I used to think mine sounded too focused - like I wanted a little more bloom or puff to it. I have listened to your recordings and I really get what you are saying. Your bass sounds very focused and it sounds great. I think that direct-ness in sound translates well to typical ensemble situations as you essentially said.

I was starting to get frustrated with my sound, so I took a different string direction and I fell in love again. (I took off the Oliv/Eudoxa combo and put on a full set of Belcantos). My Lascala has never sounded better. It has more puff to it now (which seems odd that I got it from going from gut core to steel), but it still cuts through the band.

Regarding the long-term problems - Arnold's hybrid seems the best of all worlds. My top and sides are carved, but the back is more durable ply. Arnold also has some unique bracing that is supposed to hold up better than other flatbacks.

Great story, and a perfect example of why everyone's mileage will vary. On the LaScala flatback ply that I sold recently, everybody loved the "bloom" but me. I used to wedge my leg against the back to dry it up a bit. Oddly enough, it was both bigger and fuller sounding *and* more focused than her previous bass to the student who bought it, so it was win-win all around. I'm curious to see how the LaScala ply roundback compares!

[Gearhead43]

Fat-back.

[pathdoc2]

I have 2 uprights, one Romanian flatback 1/2 scale and a round back Jim Labb 3/4 Hamburg Korean roundback.
They both sound fine to me. The larger bass, the 3/4 sounds fuller but I believe that is due to its larger size and not is round back.

[Bijoux]

I have both. the poll didn't let me vote twice.
They sound very different and I love how they sound with their unique voice. I give very little if any thought about their backs though...

[Gponyy]

round back for sure!!!!

[MIKMAN]

I have three rounbacks and i cherish their sound. I found, however, some flatbacks of German or Czech origin, which were real canons in terms of volume and atack. One of my closest friends bought one of them, built in Markneukirchen in the 60's. An excellent jazz instrument it served him perfectly, needing only some minor repairs during the last 20 years. Probably they need a bit more care than roundbacks in hot, dry climates.

[Paul Warburton]

To my knowledge nobody has ever proven that one type of back sounds or plays better than the other....pizz or arco.
I agree with Eric and MIKMAN in that flat back basses, especially older ones, are more prone to need repairing now and then. The glue in between the plate and the braces sometimes drys out and causes buzzing.
My two favorite basses in my life....one of each.

Obviously I couldn't vote.

[Jeremy Morgan]

Thanks to all those who took the time to respond. Some interesting comments...

I don't think that I can alter the poll to add a 'Both' category for those who like/own both - sorry!

I wonder if it would be fair to say, based on comments, particularly those from Mr Fitzgerald, that a flat back instrument might project the sound towards the front in a more directional manner?

If the back of a roundback bass is designed to vibrate, some of the sound energy will be radiated to the rear of the instrument. If/as this doesn't happen in a flatback I would imagine that this same energy (that would be lost towards the rear on a roundback) would be directed forwards. Maybe this explains the 'cannon' volume & projection comment regarding some flatbacks.

I suppose this might also explain the phenomena of a bass that sounds quiet to the player (from their playing position) but loud to a listener stood in front of the instrument.

[Ken McKay]

Jeremy,
I agree wholeheartedly with Paul W.

Both types are successful and although there are some differences in projection and sound, the fact that both types are in all major orchestras throughout the world is a testament them being equal.

Read Andrew Brown's dissertation if you want to know the specifics. It is all there. Look earlier in this thread for the link. Andrews work is extremely important if one takes the time to understand it.

[drurb]

Originally Posted by Jeremy Morgan

Thanks to all those who took the time to respond. Some interesting comments...

I don't think that I can alter the poll to add a 'Both' category for those who like/own both - sorry!

I wonder if it would be fair to say, based on comments, particularly those from Mr Fitzgerald, that a flat back instrument might project the sound towards the front in a more directional manner?

If the back of a roundback bass is designed to vibrate, some of the sound energy will be radiated to the rear of the instrument. If/as this doesn't happen in a flatback I would imagine that this same energy (that would be lost towards the rear on a roundback) would be directed forwards. Maybe this explains the 'cannon' volume & projection comment regarding some flatbacks.

I suppose this might also explain the phenomena of a bass that sounds quiet to the player (from their playing position) but loud to a listener stood in front of the instrument.

If it were only that simple.

[bankruptselling]

I prefer roundbacks, if only because I find them to be more comfortable to lean against me, and more attractive. Let's be honest, looks ARE important in a bass. If you're really passionate about it, don't you want it to look nice, too?

I read on a website: "Roundbacks with their arched shape and harder wood construction almost never crack. The braces on the flatback don't allow for the wood to expand and contract and eventually the back breaks free from the braces or cracks or both."

[CellarDweller]

About two weeks ago, I had the opportunity to play a lot of different basses in one very nice large room. I was the only player there, so I could really hear what I was doing. There must have been close to 40 basses there. It was overwhelming, of course, and I did not play them all. I did play a Prescott (my first time to actually play one), as well as some other basses made by very well-known makers, both older and newer.
I had been looking at web pictures prior to my visit, and I had an idea of what phusical characteristics I thought I would like.
None of my notions were borne out by the actual experience. Flat or round back did not seem to matter. Size of bass was not determinative, either. My favorite bass was a 5/8 size that had personality and power to spare. It was more than five times my price range, though, but I could understand why.
The bass I bought is a carved flat back of Tyrolean origin, estimated to be from the 1880's. It has had the (flat) back replaced at some point. Although strung with Spirocore Mittels, it has a dark and commanding sound (also surprisingly warm) with the bow. There is a complexity to its sound I never heard with my Epiphone, which will remain my main jazz and gigging bass. The Tyrolean is extremely lightwieght, too, and is probably blockless according to the seller. It has the hatpeg tuners and looks old, with fairly wide ribs, big shoulders, and that large expanse of flat back. The projection and resonance is remarkable to me. When trying instruments out, one against the other, it seemed to me that all the phyisical characterisics take second place to sound and playability, and are actually lost in the total personality of each bass. YMMV, IMHO, etc.
Tom

[drurb]

Originally Posted by CellarDweller

When trying instruments out, one against the other, it seemed to me that all the phyisical characterisics take second place to sound and playability, and are actually lost in the total personality of each bass. YMMV, IMHO, etc. Tom

Amen!

[Herbie 80's]

I've been curious about this too.

My teacher has a flat back, and I have a roundback. Different basses aside, his seems to project fuller, in a wider direction than mine, where mine is more focused to someone in front of me.

That might be because of the Rabbath end pin though.

[drurb]

Originally Posted by Herbie 80's

I've been curious about this too.

My teacher has a flat back, and I have a roundback. Different basses aside, his seems to project fuller, in a wider direction than mine, where mine is more focused to someone in front of me.

That might be because of the Rabbath end pin though.

Different basses aside? I thought you were focusing on the difference in the two basses.

Now, different basses aside, I'd say what about strings, setup, players, etc.?