New DIY MTM Towers designed by Dennis Murphy and Paul Kittinger

[jonas]

Thanks for the reply. It is always nice to know that people still enjoy the item years afterward. I'm definitely leaning toward the dome version from what I've read so far. I drive my Dittons with a Bryston b100sst which, to my ears, has enough sparkle. And, even though the Dittons are a bit too dark and boomy, I still really enjoy their sound. I don't really know what is pulling me toward this er18 build as I originally wanted to build the Zaph waveguide TMM, although I must admit that I am interested to hear a ML-TL. If they go almost as low as the Dittons I would be happy, and astonished!

Just attempting to source parts at the moment and fretting over every variable. I am totally new to this! Thanks again for your listening impressions...

 

[mattsk8]

I've never heard that Bryston, but from what I have heard from them I'm sure it's a phenomenal amp. I was using an Adcom 5500 amp and a B&K Reference 50 pre for mine, I just replaced those with a Carver 1.5t amp and a Spectral preamp. I'll say again these are incredibly transparent speakers, and the difference is stunning. The Carver has a tad more forward midrange than my Adcom did (in a good way). And that Spectral is an amazing preamp that doesn't color the sound at all, it just plays everything insanely well. My B&K had great sound, but that Spectral lets so much through that I'm hearing my CDs for the first time again.

These have great sensitivity so you don't need huge power to make them sing, but IMO they play a lot better if you have a decent size amp with some headroom.

 

[Swerd]

… although I must admit that I am interested to hear a ML-TL.

Just attempting to source parts at the moment and fretting over every variable. I am totally new to this! Thanks again for your listening impressions...

jonas – Once you hear the bass from the ML-TL ER18s, you will be glad you went to the effort of building them. At first, compared to the "dark and boomy" sound that you are used to hearing, the ER18s may sound like something is missing in the bass. As you listen to your music collection you will eventually find something that startles you, bass you hadn't heard before. Nothing is missing in the ER18's bass, except the muddy boominess that shouldn't be there.

As you have questions, just ask here .

I have the ribbon version, and I still consider swapping to the the dome because if I had to dig, my only complaint is the highs are maybe a tiny bit too sharp. But I can't say if one is better, I've never heard the dome version.

matt – Instead of replacing the tweeter (that really requires a new cabinet and crossover), try adding a 1 or 2 ohm resistor at the plus terminal of the ribbon tweeter. Maybe a slight change in the balance between the tweeter and woofers is all you need.

 

[jonas]

Swerd, would the same tweak apply for the dome as well? That is, adding a 1-2ohm resistor on the positive side of the tweeter terminal to tame it a bit? Thanks, Jonas

 

[Swerd]

Swerd, would the same tweak apply for the dome as well? That is, adding a 1-2ohm resistor on the positive side of the tweeter terminal to tame it a bit? Thanks, Jonas

Yes, that can be done for any tweeter.

 

[mattsk8]

matt – Instead of replacing the tweeter (that really requires a new cabinet and crossover), try adding a 1 or 2 ohm resistor at the plus terminal of the ribbon tweeter. Maybe a slight change in the balance between the tweeter and woofers is all you need.

I could def do that. The main reason I wanted to try it is just to hear the dome version. But you're right, the baffle rebuild is why it'll probably never happen, the Fountek is quite a bit bigger than that Dayton.

 

[mattsk8]

Jonas, just remembered something from a while ago. My cousin and I have both been hugely into stereos since we were kids. About 6 months ago I told him I wanted to try to build something that sounded better than the ER18s. His response was... "That's going to be really hard, first you'd have to be able to find something that needs to improve". Just thought that was a pretty classic response, for what it's worth

 

[tom.terrific]

I completed my ER18 MTM build a year ago last December, so while the "new" has worn off, we're still stoked every time we put music on. My wife enjoys Classical, New Age, and vocalists like Il Divo, Jackie Evancho, & Josh Groban. I lean toward Fusion Jazz and Progressive Rock. Pink Floyd, Steely Dan, Rush, Weather Report, Return to Forever, etc… But we have a substantial music library and enjoy many genre.

The sound quality from these speakers is superb. There are no funny colorations that i can discern to make them "sound amazing”. Just clean and accurate sound. They do exactly what they're supposed to do. They disappear and leave you with just the music.

Historically, ribbon tweeters sounded "buzzy" to me, and/or give me a headache with prolonged listening. But Dennis and Paul both know their stuff, and I elected to go with the ribbon tweeter build. I doubt that I'd have been disappointed with the soft dome, but I'm very pleased with the ribbon. There’s no buzz and I can listen for hours on end without fatigue.

Before I built these, my main system speakers were DCM TimeWindow 3’s. Another Transmission Line design. They sound great too, and I never got tired of them. But I always ran them with a sub. They didn’t have the authority on the bottom end. The ER18 MTM doesn’t need a sub. The bass is effortless and natural, and plays plenty deep.

My listening room is 15’x20’ and these are a good fit, giving me the best sound I’ve ever had in my home. I couldn't be more pleased.

 

[Swerd]

Thanks for your owner's impressions, always valued.

People will always ask, what amp or receiver do you use to drive them?

 

[jonas]

Thanks everyone,
My ER18 build is somewhat stalled these days, buried under a list of other chores at the moment. I appreciate your comments though and am looking forward to putting a pair together someday. Trying my best to be patient!!

 

[MALIK_BRODER]

Good looking project. Might build one.... Really looking for a single driver design, though.

 

[Researcher]

Hello to everybody, this is my first post here. I'm very interested in building a pair of these for a small room, still had not bought any parts. Recently I got this amp which outputs 8 watts per channel and has an impedance selector in the backside from 4 to 6.3 ohm and from 8 to 16 ohm.

I wonder if the ER18's could be a good match for this amp, I tested a good variety of speakers and it seems to work best with those around 89 db or more in sensitivity, anything below that simply lacks power, does anyone has measured the efficiency of the ER18s??

Thanks!

 

[slipperybidness]

Hello to everybody, this is my first post here. I'm very interested in building a pair of these for a small room, still had not bought any parts. Recently I got this amp which outputs 8 watts per channel and has an impedance selector in the backside from 4 to 6.3 ohm and from 8 to 16 ohm.

I wonder if the ER18's could be a good match for this amp, I tested a good variety of speakers and it seems to work best with those around 89 db or more in sensitivity, anything below that simply lacks power, does anyone has measured the efficiency of the ER18s??

Thanks!

I'm gonna steer you away from tubes for these speakers. You are gonna spend a lot of time, sweat, and $ to build some really accurate speakers---then you are gonna color the sound by using a wimpy tube amp

I own a pair of the Alexis-branded Philharmonitors, designed by Dennis Murphy (same designer). I had planned to run those on my cloned Dynaco ST-70 tube amp with true 35WPC. What I found is that at moderately high volumes, I could hear the amp struggling to keep up.

My suggestion is that if you want to build ER18s, then get a solid state amp from ATI, Outlaw, or many other brands.

On the other hand, if you are set on getting a low power tube amp, then get sensitive and more forgiving speakers to match.

 

[Swerd]

Hello to everybody, this is my first post here. I'm very interested in building a pair of these for a small room, still had not bought any parts. Recently I got this amp which outputs 8 watts per channel and has an impedance selector in the backside from 4 to 6.3 ohm and from 8 to 16 ohm.

I wonder if the ER18's could be a good match for this amp, I tested a good variety of speakers and it seems to work best with those around 89 db or more in sensitivity, anything below that simply lacks power, does anyone has measured the efficiency of the ER18s??

I agree with slipperybidness. 8 wpc will produce sound from these speakers, but won't be nearly enough to drive them well. Probably the mid range and treble will sound alright, but the bass output will suffer.

These speakers are 4 ohms and have a conservatively estimated sensitivity of about 88 dB. Basically similar to the Salk HT2-TLs. They aren't a tough load to drive (they don't go under 4 ohms) and most any AV receiver can easily drive a pair of these speakers.

If I had to pick a low power limit, I'd think any amp that can deliver an honest 50 wpc could drive them. But they can easily handle – and sound very good – with higher powered amps, up to about 250 wpc. But an 8 watt tube amp probably won't cut it.

 

[Researcher]

Thanks for replying, some years ago I bought this crappy speaker system according to the manufacturer the front towers have 89 db, and can be loaded from 4 to 8 ohms. I've been playing the tube amp hooked to these speakers and they fill the small room (about 18L x 13D x 10H feet) without too much effort, it depends on the recording/kind of music but usually I never need to surpass the 12 o'clock position; however the bass output it's not the big deal, not that I need a lot anyway!.

I had planned to run those on my cloned Dynaco ST-70 tube amp with true 35WPC. What I found is that at moderately high volumes, I could hear the amp struggling to keep up.

So what did you finally hooked to the Dynaco? I'm curious!

These speakers are 4 ohms and have a conservatively estimated sensitivity of about 88 dB. Basically similar to the Salk HT2-TLs. They aren't a tough load to drive (they don't go under 4 ohms) and most any AV receiver can easily drive a pair of these speakers.

I had an idea they were between 88-89 db, but wasn't so sure, thanks for the info. Maybe I should shoot for something like this?

 

[slipperybidness]

So what did you finally hooked to the Dynaco? I'm curious!

Actually, I found that the Dynaco ST-70 sounds dang good driving a pair of Definitive Technology SM-350! It drives these very well and the sound is excellent.

Furthermore, there was another member on this site that ended up going with the larger DT SM-450 for his Dynaco after I rec'd the SM-350. He came back to report that he could not be happier with the sound quality that he was able to get for something around $300 for the 450 on sale.

 

[Swerd]

… some years ago I bought this crappy speaker system according to the manufacturer the front towers have 89 db …
I had an idea they were between 88-89 db, but wasn't so sure, thanks for the info. Maybe I should shoot for something like this?

That brings up the always interesting question of just how optimistic or pessimistic a speaker designer is when rating a speaker's sensitivity. It's difficult to know if the 89 dB rating of those speakers you bought was honest or too optimistic. Many manufacturers have been known to exaggerate sensitivity, but few if any underestimate it.

I do know that Dennis's designs are usually rated on the conservative (far-from-optimistic) side. So the ER18 MTM might compare well against those speakers you now have.

I would guess that Curt's DIY designs also might be similarly conservative in their sensitivity rating. So 92 dB would be significantly more sensitive than 88 or 89 dB.

You seem to be wedded to that 8 watt amp. Because I have no experience with such low powered amps, I couldn't guess how the ER18 MTMs might work with it. I've heard SongTowers (a similar design to the ER18 MTM, but less sensitive) driven by a 35 wpc tube amp, and it was surprisingly good.

 

[Researcher]

You seem to be wedded to that 8 watt amp. Because I have no experience with such low powered amps, I couldn't guess how the ER18 MTMs might work with it. I've heard SongTowers (a similar design to the ER18 MTM, but less sensitive) driven by 35 wpc tube amp, and it was surprisingly good.

I like very much the sound of this 8 watt tube amp, even with those crappy Pure Acoustics the sound is quite pleasant. In the past I used an old Pioneer receiver, a Marantz receiver and a NAD 2 channel amp with this same pair of speakers and according to my ears none tops the quality of the tube amp...and perhaps I like watching those glowing tubes too...

So I think I'll finally build the ER18's maybe next year, need to save some funds first!. If they don't work well for the tube amp, they will for the NAD or the Marantz. Besides price, there's any difference in sound between the dome tweeter version vs the ribbon? I read somewhere the ribbon was quite "bright" compared to the dome version, has anyone listened both?...I recently built a pair of P. Carmody's Speedsters and I like how the ribbon (NeoCD 1.0) was voiced in that particular design, however I'm doubtful about which would be the advantage (if any) of going ribbon with ER18s.

 

[Swerd]

Besides price, there's any difference in sound between the dome tweeter version (of the ER18 MTM) vs the ribbon? I read somewhere the ribbon was quite "bright" compared to the dome version, has anyone listened both?...I recently built a pair of P. Carmody's Speedsters and I like how the ribbon (NeoCD 1.0) was voiced in that particular design, however I'm doubtful about which would be the advantage (if any) of going ribbon with ER18s.

I heard single examples of both the ribbon tweeter and dome tweeter versions, back when Dennis was developing these designs. My strongest memory was that it made little difference to my ears. Dennis did two versions with different tweeters primarily to offer a choice in prices for builders. It took an effort for me to tell the difference.

Both designs integrate tweeters with the mid woofers as smoothly as possible, and sounded excellent across the crossover range. The ribbon tweeter was ever so slightly less hissy sounding in the higher treble range on certain music passages, and the dome tweeter measured with less distortion at its somewhat lower crossover frequency. So I thought it was a toss-up.

When Dennis voices his designs, he carefully chooses the crossover frequency to minimize any tweeter distortion, and to maximize mid woofer off-axis dispersion. He also works carefully to keep mid woofers and tweeter in phase with each other within about an octave of the crossover frequency. In my experience & opinion, those design features tend to make more of an audible difference in sound quality than the actual nature of the tweeter.

 

[spaeny10]

Hello everyone,

I am new to speaker building and I need a little guidance on the cross-over. I purchase the shopping list provided on this first page of this thread and it had a .10mH air core that needs to be unwound to read .06. I do not have a way to unwind and measure it. Does anyone know about how many winds would need to be removed to get it within the 10% specification of .06mH?

In the notes below it says "XX coils" but I am not sure what that is suggesting.

Any help on this is appreciated.

Shawn