Always late to the party: Another ER18 build (Rosewood & Maple, Experiments with Joinery)

[lsiberian]

You are not a novice let's get that one clear. You have more natural talent woodworking than most of the builders in this hobby. Your cabinet looks way better than anything I've built. Boominess in a speaker does can indicate a high tuning, but it can also be the recording. Good speakers punish bad recordings. I know you used fill, but you might try adding a bit more to see if that helps. FYI most of us cut the driver holes before we glue the box together then if something goes wrong you aren't out the entire box. I've had a baffle go wrong before too.

 

[Swerd]

They are currently driven by an old Harmon Kardon AVR20ii, 50 or 60 wpc, alleged…

What would be the ideal amount of power to put into these, given the option?

Your Harmon Kardon receiver ought to be enough power to drive the ER18 MTMs. They are relatively easy to drive – high power is not required. But the good thing about these speakers is that they are capable of handling much higher power without trouble. I've heard them driven with 200 wpc, and I would guess that 300 wpc wouldn't be too much. So I'd say anything from 50 to 300 wpc would be great. That should give you plenty of latitude if you look for bargains in used amplifiers.

The major audible difference I would expect to hear from more power, let's say about triple what you now have, would be that bass sounds cleaner and more "solid".

Is there an ideal angle-in for the ER18s, or recommended placement away from the walls? It almost feels like I want to toe-in quite a bit when I'm sitting in the listening position and enjoying an album, and then angle them back out when I'm doing other things in the house and they're on for background music.

Feel free to play with toe-in angle and placement away from walls. There is no defined rule, as rooms and listening positions vary widely. Whatever you like is what's best.

… a friend of mine who records the Baltimore Symphony…

Dennis is never one to brag, but I'll do it for him .

Last July at the Capital AudioFest, Dennis met a classical music recording engineer who does work for the Baltimore Symphony Orchestra as well as for the Washington NPR classical radio station, WETA. He loved the Philharmonic 3 speakers and wants to buy a pair, and sell his overpriced German-made horn speakers. I believe Dennis, a classical musician himself, is justifiably proud of that.

 

[pkitt]

Dennis alerted me to the questions about boomy bass. First, though, the cabinets are absolutely gorgeous and you should be very proud of your handiwork. As far as the boomy bass is concerned, I have the very same problems on some CDs and I suspect the boominess is occurring around 100-125 Hz. The reason I mentioned this frequency range is because that's exactly where I have a room resonance that's excited by my right-channel speaker with the boomy sound identical to what was described. I do have the same compositions on more than one CD and while one may be boomy, the other won't when playing the very same score. The amount of boom is dependent not only on the CDs but the music content. You could increase the stuffing density and probably mitigate this a bit, but then you'd also be increasing F3 and lowering the output in the 30-40 Hz range, which might then sound a bit weak on the larger quantity of your CDs that don't boom. My speakers are located with their backs only about 6" away from the wall, and if I pull them out to a couple of feet away, the boom goes away. Maybe only one of your channels is being affected due to a similar room resonance. You could determine this by playing a boomy piece in mono and use the balance control on your driving amplifier to go back and forth from right to left for comparison. Maybe just a location tweak will make it all better!? But if it doesn't, I guess you'll just have to replace some of your CDs.
Paul Kittinger

 

[Irvrobinson]

You are not a novice let's get that one clear. You have more natural talent woodworking than most of the builders in this hobby.

I'll say. This is amazing work. If I had his talent I'd make a career out of it. Not with speakers necessarily, but with furniture-making in general.

 

[mattsk8]

I'll say that adding more power made a difference on my ER18s. I started out w/ a Pioneer SX-1050 and the sound was great, but no remote and I was constantly dealing w/ the little quirks that go along w/ using vintage equipment.

So I sold my Pioneer, and I purchased a Harman Kardon HK3490 (this is my music only system). The argument about whether or not power matters or you can hear the difference between amps is endless; but these speakers sounded incredibly better through the Pioneer (everything flat on both receivers, and no loudness used). I remember when I first plugged in the HK, and was mildly disgusted, wondering what I was thinking.

At this point I decided to spend some coin. I purchased a used Adcom GFA 5500 amp and a B&K processor and finally got back to the Pioneer's sound. I guess all I'm saying is, more power did make a difference on mine. I almost can't tolerate them through my garage stereo, which is a circa 1990 Kenwood stereo receiver that's rated at 85w/ch.

The irony is, the Pioneer I had is rated at 120w/ch @ 8ohms, while the HK is also rated at 120w/ch @ 8 ohms. I think the Adcom is 200w/ch @ 8 ohms and the ER18s handle the abuse well . Not trying to talk you into spending loads of cash on new equipment, just some food for thought. These ER18s are great sounding speakers, I've heard them stacked up next to many different speakers that I would also consider very good, and the ER18s hold their own for sure (and in many ways they out-perform IMO).

All that said, I do still catch a little weirdness on the lowest part of the bass line in Fleetwood Mac's, The Chain (regardless of the recording, I have 2; one is Rumors on SACD and one greatest hits on standard). Listen specifically between 3:04 and 3:20. This might still be Fleetwood Mac's doing, but I'm just throwing it out there.

[video=youtube;ep3bZD2lpTU]http://www.youtube.com/watch?v=ep3bZD2lpTU[/video]

 

[mattsk8]

The cabinet work and your speakers are stunning BTW, well done . If you're ever anywhere near MI, hit me up. Otherwise, I suggest attending some DIY get togethers; at these get togethers you really get a taste for what's available (and an appreciation for what you have there w/ your ER18s). It also gets you over the most difficult part of DIY speakers, which IMO is the inability to listen before you purchase. I actually went to AXPONA last year w/ my son, and that gave me an even greater appreciation for our ER18s (and that's after spending an entire day listening to "cost is no object" systems).

That said, if you got bit by the DIY speaker bug, its a good thing you're a bachelor because its a downward spiral . I'm working on my 5th set of speakers now (I actually have my 4th and 5th going at the same time).

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[djbachelor]

WOW thanks for all the positive encouragement, guys. It really means a lot, as I have gained a lot of respect for the vast knowledge present in the forum (as you can see, I have been a member since 2009. I'm a wallflower.) I should have posted a little earlier in the process for times when my confidence wavered (like, between March and August)! My goal was to experiment and push the envelope on things I’ve wanted to try, and ideally come up with a neat-looking design which my wife would allow in the living room for years to come (that’s right, I am a Bachelor--just not by marital status!) Plan B was to spend so much time on them that she’d feel too guilty telling me they weren’t good enough for the living room! Either way, I’d win.

I don't think I'm familiar with your recording of the Crown Imperial. Do you know who the recording engineer was?

Dennis alerted me to the questions about boomy bass. First, though, the cabinets are absolutely gorgeous and you should be very proud of your handiwork.

Dennis and Paul, Thank you both for the compliments on my work so far, and thank you so much for sharing your expertise and efforts with us through this fantastic design. It's an honor to have you weigh in on my version of your speakers.

As far as the recording of Crown Imperial, it's of the Chicago Symphony Orchestra Brass on the CSO Resound label, which I found on Spotify… so far, I can’t find information which identifies the recording engineer.

I listened to the same recording through the best headphones I have on hand, Sennheiser 280s (reputedly pretty flat--even if “unexciting” and an underwhelming low-end, far as I understand) and I noted two things. One--I definitely can hear what I had identified as a “ringing” in the bass drum. I think this is accurate and I should have thought of this as “sustained decay” instead of ringing; of course orchestral bass drums are very large, not like a marching drum or kit drum, and they do reverberate for a long time if not manually dampened (which they usually are). Hmm, maybe they’re not manually dampened in this passage, I wish I could check the score! (Except I was a clarinetist, and I have no idea what percussion notation represents.)

2[SUP]nd[/SUP]--Although I could identify the sustained decay in my “better headphones,” the overall balance was completely reasonable--it wasn’t overpowering in the least. This leads me to believe that I might still find benefit in stuffing the speakers a tiny bit more, and trying some testing with positioning/angle/running each speaker in mono, as Paul advised. I’d hate to lose the “oomph” on the low-end from overstuffing, of course.

Wow! The Rosewood and Maple cabinets are wonderful. Very well done. What kind of finish are you planning. Something like a clear coat?

Thanks! I lack patience when it comes to the later stages of projects (that's why there are projects all over the house which are 90% complete, I don't want to do a poor job on that last 10%!) So finish will be something easy, no 5 step application processes here! I have used tru-oil in the past (a very durable gunstock finish) and I thought I might try waterlox on this one.

I know professionals that wouldn't even attempt this. ... I don't suppose you have the equipment to run a frequency test?

Heh, and for good reason, I am sure--with experience comes wisdom! I had the privilege of being delightfully oblivious when I started about the perils and headaches that my imagination and stubbornness had set in my path.

As far as the frequency test-- I actually purchased a SPL meter (one of the ~$100 recommended models) when I was trying to dial in my sonosub; but I haven't figured out how to make use of it yet. Feel free to post a link to the tutorial, again...

Those inlaid dovetail joints will reduce hardwood resonances due to the use of two different types of wood

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Besides it appears that the hardwood is really a thick veneer over an inner MDF cabinet.

That was my plan with the two types of wood, exactly. I even used two types of glue, just to make sure!! ;-) It’s true that the inner cabinet is .5” MDF (.75” for the front baffle and bracing); the resawed hardwood is planed to ~.30”, except for the front baffle and top piece, which are about ~.70”. Final width is about .25” wider than spec’d on the plans. Speaking of which, I wondered if I shouldn’t have cut the chamfer a little deeper around the front baffle. Would there be an acoustic advantage to making it a little more pronounced, or am I just waffling over aesthetics at this point? (It would be tougher to modify the chamfer on the curve at this stage, because the center for the radius was cut out with the speaker hole.)

I'll say. This is amazing work. If I had his talent I'd make a career out of it. Not with speakers necessarily, but with furniture-making in general.

Thank you, also, for the generous compliment. As far as being a novice--I guess we could say that I am an ambitious, stubborn novice; but I don’t get paid, and I am self-taught (/academy of youtube), usually figuring most things out for the first time as I go--if you watched me in the shop, it would probably seem pretty funny and clumsy. Plus a lot of down time, sitting on the stool while trying to figure out the next step. Furniture-making is a fun idea, except that I can’t even get around to re-gluing those two chairs which have fallen apart and are sitting on top of a workbench in the background of one of these pictures!


Mattsk8, I’d love to get a dedicated 200wpc or so behind these as you’re saying, like an XPA-2 or XPA-200, etc; I think that will be my next upgrade. I’m also a little bewildered looking into pre-processors, external DACs etc (as I’m mostly streaming music and playing albums ripped to the Hard Drive)--but I’m supposing that the greatest advantage would come with running the pre-outs on the HK to an external amp.

 

[panteragstk]

Novice. Right. I'll show you novice when my build starts. Great job so far.

 

[Swerd]

A couple of unrelated thoughts…

I have a recording with a very loud concert bass drum. Aaron Copeland's Fanfare for the Common Man by the Atlanta Symphony Orchestra on Telarc. If you can get a hold of that, does it resemble what you have previously described as bass ringing or resonance?

For a little inspiration for applying a finish, try wetting a cloth with mineral spirits and wiping a part of the cabinets. While wet, it simulates the color you might get with a clear finish. I would hope that a clear penetrating oil would make the rosewood grain visually pop out, while making the maple a little warmer, but not too yellow. You probably have plenty of scrap pieces to test finishes.

Thanks for showing us your spectacular speaker cabinets. I hope you enjoy listening to them for a very long time.

 

[pkitt]

On stuffing changes...

I took a look at the cabinet design info and I used a stuffing density of 1 lb/ft3 in this design. This is the highest stuffing density whose effects I can confidently predict and more than this should not be required. On a personal basis regardless of the stuffing density of any design I've created, then built, I've never felt any need to tweak the density from what I modeled, and my personal builds sound essentially identical in my home as at the various DIY venues I go to. Many people do tweak the stuffing density as part of the voicing process, and that's fine, but I honestly don't recommend it.
Paul

 

[pkitt]

I wasn't quite as clear as I wanted about increasing the stuffing density. You certainly could increase it just to see if it solves your problem, but I don't think it will without possibly also causing other problems. I use Martin King's software for all of my TL modeling and Martin limited his validation of stuffing effects to a maximum density of 1 lb/ft3. The software does not prevent using a higher density, however, and will predict performance based on whatever is used, but Martin simply cannot stand behind it. Frankly, though, if a TL design seems to require a significantly higher density, there may be problems with the design that should be addressed first. Stuffing density and location in a TL are meant to be used to optimize the performance, not cover up design defects. As to stuffing in my personal designs and builds, I meant to say "regarding" instead of "regardless".
Paul

I took a look at the cabinet design info and I used a stuffing density of 1 lb/ft3 in this design. This is the highest stuffing density whose effects I can confidently predict and more than this should not be required. On a personal basis regardless of the stuffing density of any design I've created, then built, I've never felt any need to tweak the density from what I modeled, and my personal builds sound essentially identical in my home as at the various DIY venues I go to. Many people do tweak the stuffing density as part of the voicing process, and that's fine, but I honestly don't recommend it.
Paul

 

[Irvrobinson]

All that said, I do still catch a little weirdness on the lowest part of the bass line in Fleetwood Mac's, The Chain (regardless of the recording, I have 2; one is Rumors on SACD and one greatest hits on standard). Listen specifically between 3:04 and 3:20. This might still be Fleetwood Mac's doing, but I'm just throwing it out there.

Just out of curiosity I listened to The Chain in that time interval, and it sounds like John McVie on an electric bass plugged into the mixing console, hitting some notes in the 40Hz range. On my system that passage sounds perfect and well-defined, and not especially powerful either, just a pretty typical electric bass line for the 1970s. (Back then bass was mixed to be more subtle than is typical in more recent popular recordings. Nowadays it seems people want to hear and feel ridiculous thumping on their car audio systems.)

 

[djbachelor]

I wasn't quite as clear as I wanted about increasing the stuffing density. You certainly could increase it just to see if it solves your problem, but I don't think it will without possibly also causing other problems. I use Martin King's software for all of my TL modeling and Martin limited his validation of stuffing effects to a maximum density of 1 lb/ft3. The software does not prevent using a higher density, however, and will predict performance based on whatever is used, but Martin simply cannot stand behind it. Frankly, though, if a TL design seems to require a significantly higher density, there may be problems with the design that should be addressed first. Stuffing density and location in a TL are meant to be used to optimize the performance, not cover up design defects. As to stuffing in my personal designs and builds, I meant to say "regarding" instead of "regardless".
Paul

Thanks for the clarification. I divided 32oz (roughly) between the two cabinets--so I am probably just a little shy of the 1 lb/ft3 density in at least one of the cabinets.

Another variable and I'm not sure about it's impact here: I used a port from Meniscus with an outer and inner flare... This means that there is essentially no length of 3" tube--just two big flares fastened together. Might this be undermining the design of the MLTL?

 

[pkitt]

I don't know how much it might affect what you're hearing, but the port diameter and length I specified is only applicable if neither end is flared. A flare on either or both ends requires the port to be longer in order to create the same tuning frequency for the same diameter. So if your port's length is as I specified for a non-flared port, your system is tuned higher than what I designed it to be, unless Meniscus took that into account and provided the flared port with the correct (?) longer length.
Paul

Edit #1: I just checked the original design and I specified a 3" diameter port 2-3/4" long. If the flared port you've used is also 2-3/4" long, and 3" in diameter, it's too short, but if it's longer, it's probably okay. A too short port would increase the tuning frequency and cause a peak in the response at the knee in the curve, gradually sloping down to flat before 100 Hz.
Paul

Edit #2: I just looked at the Parts List for the kit for this design at Meniscus Audio. The port was described as having a 3" diameter with a 4-1/2" length. So, it would appear the length of the supplied port was increased appropriately by Meniscus.
Paul

Thanks for the clarification. I divided 32oz (roughly) between the two cabinets--so I am probably just a little shy of the 1 lb/ft3 density in at least one of the cabinets.

Another variable and I'm not sure about it's impact here: I used a port from Meniscus with an outer and inner flare... This means that there is essentially no length of 3" tube--just two big flares fastened together. Might this be undermining the design of the MLTL?

 

[TheWarrior]

Beautiful! But on the subject of sound, I am curious how a multi-piece baffle sounds? Its looks are exceptional, but I wonder how you feel about the sound after several hours of listening and break in. Please keep chiming in with updates, but for now, just go listen and enjoy your work!