Currently have Modula MT bookshelves (Jon Marsh design from 2006). How much have things improved?

[Shrek6]

My current main set of bookshelf speakers are a DIY project from ~2006 by Jon Marsh (using Dayton RS180 woofers and Seas 27TDFC tweeters).

I'm looking to upgrade but I'm wondering how much things have improved since this design. The biggest issue with these is that they have incredible harsh distortion if you bottom them out, and adding a subwoofer is not something I particularly want to do at this time (despite a lot of my music being bass heavy).

Specifically I'm looking at the CSS Criton 2td-x towers or MTMs.

 

[alex-z]

In terms of driver + crossover quality there is minimal difference upgrading to modern parts in the same price category.

The biggest change with modern designs is the integration of tweeter waveguides and optimized baffle geometry. This drastically improves the off-axis response, and therefore room reflections. Most CSS kits lack these things, which IMO is unacceptable given the pricing.

Not having a subwoofer is fighting with both hands tied behind your back. Even a small sealed 10" sub will dramatically improve the dynamic range and distortion profile of your system, beyond what tower speakers can achieve. In residential sized rooms the proper location for stereo imaging and bass quality often conflicts.

Parts Express sells just such a kit. I would toss one in each front corner and hook up a good amp like a Hypex NC252MP to power them.

Dayton Audio 10" Reference Series HO Subwoofer and Cabinet Bundle 600 Watts

Dayton Audio 10" Reference Series HO Subwoofer and Cabinet Bundle 600 WattsAbout the CabinetThis particular cabinet is designed specifically for the Dayton Audio 10" Reference Series High Output subwoofer, but works for any subwoofer with an overall diameter of 10-9/16" or less, and a cutout...

www.parts-express.com

 

[Heinrich]

Specifically I'm looking at the CSS Criton 2td-x towers or MTMs.

I'm preaching a third possibility *g* A three way.

MTM was an attempt to realise the d'Appolito concept (asking for third (!) order x/over and small driver to driver distances etc). But then the industry departed from the proper path and issued barely working designs w/ crazy off axis resonses, very much a problem as experienced with lying center spearkers. So, MTM wasn't on top of my recommendation list.

A (single) subwoofer won't help that much either. Erin does IM tests that reveal the in cases irrelevant returns in regard to clarity of midrange, what many are actually after.

Depending on your budget you may want to investigate the feasibility of a true three-way design. Add an in enclosure and position separated bass for each speaker, running up to 160Hz++ instead of that common 80Hz, in stereo, means one each, two in total. That would technically stand as a three-way conversion, but w/o the hassle.

To waveguide the tweeter may be beneficial, but an alternative is to lower the x/over frequency. SEAS is known for robust and otherwise competent designs. But, obviously, no plan is public for such. If the tweeter burns, the loss may be not too bad in the grand perspective, as you planned for something new anyway ;-) On the technical problems w/ DIY'ing the x/over, get a grip on measuring equipment, as a final test of any build would be a good move anyway.

edit: looked up the CSS speakers. Budget?! Get yourself a pair of KEF R3 (meta), be happy for the next decade or so ...

 

[JohnnyNG]

Erin does IM tests that reveal the in cases irrelevant returns in regard to clarity of midrange, what many are actually after.

I have to admit to being surprised at how relatively small the improvements seem in those tests. Is this perhaps due to the 80Hz high-pass used and why you recommend 160Hz++ for separate bass enclosures? And would any improvements seen be due to a reduction in excursion or other factors?

 

[Heinrich]

I have to admit to being surprised at how relatively small the improvements seem in those tests. Is this perhaps due to the 80Hz high-pass used and why you recommend 160Hz++ for separate bass enclosures? And would any improvements seen be due to a reduction in excursion or other factors?

Improvements seem to be a rare bird in his tests. There are many reasons I could assume, but not verify. The recommendation for 160Hz relies on my personal, subjective impression - yep, I should have told.

For one, a sub would most likely extend bass to lower; without detrimental effects whatsoever. Big plus for many (except KEF R3 for instance).

What else to say? I cannot reasonably discuss Erin's set-up. Regarding the multitone I doubt, the spectrum is well chosen. It goes too low in frequency, as like 20Hz are very rare on orderly made recordings, and if they are present, are also low in amplitude (-10dB the least). The equal weigh on lowest bass and low/mid bass/mids doesn't reflect the actual demand from electronic dance music (EDM) which is often used to show-case bass quality. To mirror the needs with even hard rock / metal one would better chose a pre-filter that amplifies the bass by 10 to 20 (!) dB relative to the mids, while treble can be kept way lower in amplitude. But such is not yet standard, and probably won't ever be, so the industry, and informed consumers stick to what is not representative, as to not lose grounds in the comparison.

Why 160Hz? Because it works for me. I can place the extra woofers like 2..3 feet besides the mains, and still get well integrated sound. Crossing higher would tend to blurr the picture due to distortion components (!), that eminate "from somewhere else", me thinks. When well coupled together I feel that the mids get very much clearer, more impactful, sharper edges to a sonic 'gestalt' if you will. And not the least, the bass benefits either, in that bass lines distinguish more from the mids, in-room frequency response maintained to be equivalent. But that's all anecdotal.

 

[JohnnyNG]

Improvements seem to be a rare bird in his tests. There are many reasons I could assume, but not verify. The recommendation for 160Hz relies on my personal, subjective impression - yep, I should have told.

For one, a sub would most likely extend bass to lower; without detrimental effects whatsoever. Big plus for many (except KEF R3 for instance).

What else to say? I cannot reasonably discuss Erin's set-up. Regarding the multitone I doubt, the spectrum is well chosen. It goes too low in frequency, as like 20Hz are very rare on orderly made recordings, and if they are present, are also low in amplitude (-10dB the least). The equal weigh on lowest bass and low/mid bass/mids doesn't reflect the actual demand from electronic dance music (EDM) which is often used to show-case bass quality. To mirror the needs with even hard rock / metal one would better chose a pre-filter that amplifies the bass by 10 to 20 (!) dB relative to the mids, while treble can be kept way lower in amplitude. But such is not yet standard, and probably won't ever be, so the industry, and informed consumers stick to what is not representative, as to not lose grounds in the comparison.

Why 160Hz? Because it works for me. I can place the extra woofers like 2..3 feet besides the mains, and still get well integrated sound. Crossing higher would tend to blurr the picture due to distortion components (!), that eminate "from somewhere else", me thinks. When well coupled together I feel that the mids get very much clearer, more impactful, sharper edges to a sonic 'gestalt' if you will. And not the least, the bass benefits either, in that bass lines distinguish more from the mids, in-room frequency response maintained to be equivalent. But that's all anecdotal.

Thank you!

 

[JoshK]

I built the Modula MTM back in the day. Jon Marsh is a smart dude, a power engineer in his day job. These speakers punched well above their weight. However, I can't say much about the off-axis performance as I didn't measure that nor have I've seen such measurements.

I wished I kept those speakers but sold them to one of my buddies when I moved.