Choosing between budget RS150 MT builds.

[oldloder]

Hey Folks, I've been reading quite a lot here lately on a small budget MT to build and it's boiling down to a few choices that maybe you all can help me decide on.

For space constraints, I'm limited to a .375 or .25 cu.ft. cabinet that will hopefully be paired soon with a powered subwoofer. My young son loves to play drums and keyboard along with music, so I thought we'd build a little setup together for him to go in the room he plays his drums in for listening and playing along. Ideally, on the wall or near wall (within a foot or so) would be best and great for listening to all types of music .... but accurate. It'd be nice if at some point they could be incorporated into an H/T setup down the road, but that's not critical. I'll be running them off of the "B" speakers of my 100Wpc integrated home amp with at some point a sub (like a 10" Dayton HF in a cube sealed) on a 240W plate amp managing the crossover between it and the MT's.

So, I seem to be down to the following choices:

- Jeff Bagby's Dreydels: it seems near/on wall could be a venting issue and BSC issue?
- Paul Carmody's Girl from Ipanema - seems to fit the bill, small, made for the bookshelf - he certainly doesn't listen to hard rock, but fatigue may set in at times? What would happen if I just dropped in the TDFC instead? Would it need a crossover adjustment?
- Mudjock's RS150/BGNeo3: - This sounds really good to me being described as laid back detail? I actually have these tweets in my truck and I really love them. It'd be nice not to have to run a sub in the near future and these with the slightly larger cabs running down into the upper 40's sounds good. But near/on wall and BSC could be an issue and if driver mounting was on the side of the cabinets like the two above, it would fit better. It seems from reading that just covering the port might not be a good way to handle near wall placement.

Questions:

- One poster commented that RS150 sealed runs out of excursion at 99dB - so they are somewhat output limited or just output limited below a certain frequency?
- Seas tweeters - TBFC/G vs. TDFC/TV - do I understand correctly that the silk dome would be more forgiving of different program material, but the H1212 could be slightly more accurate? My ears are old and abused, but would young ears be even more susceptible to the fatigue?

My only education on the subject is what I've gleaned from all of your posts here. I certainly don't have a golden ear, but maybe an uneducated bronze. I'm sure these speakers are better than anything I've heard before, so maybe I'm splitting hairs here around wall placement, etc. and any or all would be more than great. But if your experienced ears have any thoughts, maybe there's a clear winner here that I'm not seeing! Thanks folks ... what you do here is really cool. :T

[Mudjock]

If you can be about a foot away from the rear wall, I don't think you'll have a problem with the RS150-Neo3PDR's rear-ported. I run mine about that close without hearing any ill effects.

If you are using the PE cabinet, like I did, you would find it very difficult to find room for a front port due to the faceplate size for the Neo3PDR. If you are building a cabinet from scratch, a slot port at the bottom might be a viable option.

[oldloder]

Thanks, Mudjock!

I will be making the cabinets from scratch ... the slot port sounds like a good idea. I think I read somewhere your tube length was about 8" ... and if I used a port calculator right, that means the tube diameter is about 2 inches ... how might I convert that to slot dimensions? Does this mean I could now mount this on wall or would there need to be BSC adjustment?

[Undefinition]

Well, personally I like all three of those designs a lot :W

But I feel obligated to derail this thread a bit... I've been playing drums for over 15 years now (my bachelor's degree was in music, and my instrument was percussion). For purposes of practicing, he MUST wear headphones. Ideally, he should wear headphones that cover his entire ear (in the old days, you might call them "cans") and block out as much outside sound as possible. It doesn' thave to be expensive. For many years I used a pair of Sony CD750, which were very nice, but parts kept breaking on me. Eventually, I got tired of the high cost of keeping them up and bought some $30 Koss headphones like these:

http://www.amazon.com/Koss-UR29-Collapsible-Portable-Headphones/dp/B00008RS97

No, they're not the Ne Plus Ultra in sound quality, but they do a pretty good job of blocking out the outside world, and they play the music in my ears at a [still] safe volume.
Trying to play drums using headphones that don't cover your entire ear is an almost useless pursuit because drums are so freaking loud the required dB level in your ear is well past the "dangerous" level.
The same dilemma happens when you try to "play along with the stereo." Again, drums are really loud, so whatever your playback system is, it'll have to do prolly 110 dB. (That's what PA systems are for) Drums in a room are loud enough as-is--trying to overpower them with a playback system means dangerous SPL levels. Whenever I rehearse with a band in a small-to-medium sized room, I have to wear earplugs.

So getting to the point... if your goal was to make something for him to play drums along with, I'd say do not pass go do not collect $200, and get him a set of closed-ear headphones. But if there is some good listening you'd like to happen in the room, then we can talk some more about designs.

...oh, one quick note. The RS150 is a bit of a bugger to run vented. The bass you can get from it is really nice, but they really can't take much power at all. According to Unibox, they run out of xmax at 3 watts, around 90 dB. Vented, they can handle more power... maybe 10 watts ~ 95 dB.

[oldloder]

I totally appreciate your concern here. :T

He uses the ear protection I use when running my chainsaws ... in fact he won't play without them ... they're very good! I'll look into those that you mentioned though. I went down to the drum studio where he may be taking lessons at and they use them there too. What could be a greater shame than to ruin the hearing of a child that wants to play music? I know how fast it can happen and I can I assure you I won't let him do that.

When he started playing along a lot with his keyboard too was when I decided to do this - not just to play along with, but these will be so great and portable that he'll be using them for listening as well in whatever room he finds himself in for years to come. It's because of his listening that he wants to play in the first place and that's one of the reasons I want him to have something "frighteningly accurate" so he can hear what people are creating. Just the other night he was playing along with some of Marcus Millers' simple bass lines the other night I had to go into the living room to hear if it was on the recording or him! It was him.

Actually, Paul, he told me he wanted to hear more jazz lately and having tuned the "Girls" for acoustic and jazz made me think I'd be on the right track with them. His likes tend more toward that than anything but he likes mellower well recorded rock like Dire Straits, but does like to cut loose occasionally with Los Lobos' "Georgia Slop" or some SRV!

Okay, everybody back in the pool!

You're good to step in like this, Paul ... I appreciate it.

[oldloder]

http://www.amazon.com/Koss-UR29-Coll.../dp/B00008RS97

They seem perfect, really.

"...oh, one quick note. The RS150 is a bit of a bugger to run vented. The bass you can get from it is really nice, but they really can't take much power at all. According to Unibox, they run out of xmax at 3 watts, around 90 dB. Vented, they can handle more power... maybe 10 watts ~ 95 dB."

Do you mean sealed, they can handle more power?

Well, that's good to know, that these designs are all relatively low volume level designs I think that's fine, though 95 dB doesn't sound like much. I'm not sure I have a great reference point for dB levels vs. normal listening levels other than 110 dB generally being considered a pain threshold! Would crossing a sub higher such as 100 or 120 Hz allow the overall output levels to go higher without breaking up? But hey, we've established we're not approaching hearing damage anyway.

[cjd]

Run them sealed with a nice 10" sub. I know, that isn't in the plans. RS265HF in a nice big box vented to 22Hz would do superbly. (I like big boxes! what can I say...)

The RS150 does amazingly well with bass, especially when you let the box size live to the size these drivers want - I love the sound. But they run out of excursion SO fast, and I have MTM's! I've bottomed mine out searching for that "oh, I want this just a little bit louder..." and not reached the SPL I really wanted.

If a sub is not an option, give the Modula MT some serious thought. The RS180 can handle a LOT more in the bass department.

C

[oldloder]

If only I had the room! That's one of the reasons I figured these designs and driver combinations would be worthwhile, because in the end they could match up well with Modulas and your MTM in an HT setup in a bigger room someday and then the HF could move to a ported box. In the end, though, I've been lucky enough to get the boy's music in this room - small and tucked away is about all I'll get away with before my wife goes :M .

[Xander]

Sorry to be a little off topic, but I have some input on headphones. I mix live concerts and wanted my own headphones. I did a ton of research and ended up buying a pair of Sennheiser HD280 Pro cans. $100 with free shipping from Sweetwater.

I bought them because of their external noise reduction and sound quality.

Very flat response. Initially to me it seemed they were a bit...dead sounding. Not sure how to explain it. They aren't enhanced in any frequency. However, they are now my favorite thing to listen on. I love how I can hear everything in the music at even very low volumes because they block out everything else. They do go very low too, you definitely don't miss out on any bass. It's just not boosted.

[Mudjock]

I cross to a sub at 80 Hz (It's only one sub and it's not centered, so I decided lower was better.) This does allow the RS150's to handle a lot more power. I think the slot port will allow on wall placement without the sound thickening up too much due to BSC issues. I can try plugging the rear port on mine and pushing them against the rear wall as a test.

If you decide to run the RS150-Neo3PDR with some version of Modulas and/or CJD's MTM eventually, I would suggest that you use the RS-28 as the tweeter. It's character is closer to the Neo3PDR than the Seas tweeters (CJD and I have both worked with and listened to RS150 based MT's with either the RS-28 or Seas 27 series tweeters).

[Jonasz]

I think you should go with the Neo3 bc it's an awesome tweeter. If not the RS28 has a similar non fatiguing character. I have both of them and I like them very much.

Here's Lou C's MTM with Neo3: http://www.lonesaguaro.com/speakers/.../RS150MTM.html

[oldloder]

I cross to a sub at 80 Hz (It's only one sub and it's not centered, so I decided lower was better.) This does allow the RS150's to handle a lot more power. I think the slot port will allow on wall placement without the sound thickening up too much due to BSC issues. I can try plugging the rear port on mine and pushing them against the rear wall as a test.

If you decide to run the RS150-Neo3PDR with some version of Modulas and/or CJD's MTM eventually, I would suggest that you use the RS-28 as the tweeter. It's character is closer to the Neo3PDR than the Seas tweeters (CJD and I have both worked with and listened to RS150 based MT's with either the RS-28 or Seas 27 series tweeters).

I'd love to know how they sound plugged and against the wall. And are you suggesting, here, that if thinking HT down the road going to the RS-28 for the MT (like Darren Kuzma's Encore)? Or just using RS-28's for an MTM and the Modulas to go with the Neo3 MT?

I think you should go with the Neo3 bc it's an awesome tweeter. If not the RS28 has a similar non fatiguing character. I have both of them and I like them very much.

Here's Lou C's MTM with Neo3: http://www.lonesaguaro.com/speakers/.../RS150MTM.html

Gee, thanks ... makes me wonder if I went with Scott's design, why not do Cryolites as mains eventually and the MTM for a center? Funny, he compares his Cryolites to the ACI Jaguars ... my stereo setup is with the ACI Spirits.

[eyekode]

In this thread there was some discussion of power handling of RS150 vs RS180.

If you are comparing an MTM RS150 to a single RS180 the MTM will be able to output a higher SPL before bottoming out.

That being said neither of these combination can handle significant power.

Modeling them in WinISD the RS180 (ported with a tune of 40hz) will run out of Xmax with only 4W at 20Hz.

The MTM RS150 ported with a tune of 47Hz bottoms out with only 7w at 20Hz.

The RS150 MTM is playing at 99db to ~50hz and the single RS180 is playing at 93db ~45hz.

I don't see any significant power handling advantage for the single RS180.

The good news is I have a pair of Cryolites and with typical non-HT material I can play them as loud as I can handle it. This doesn't mean that 93db is amazingly loud, it just means that _most_ program material there is no real content down at 20hz.

For HT I cross them at 80hz to a 12" sub in a 4 ft^3 ported box.

[oldloder]

Sounds plenty loud enough for my application. What do you think of the Cryolites? And just out of curiosity, why don't you use the sub for listening material too? Any idea where you'd cross them if you did?

Santa and the itch are getting to me ... I'm starting to lean toward a .25 cabinet - just seems more flexible in terms of space and fitting in wherever they may be used.

But I do have a question regarding baffle sizing, though. It seems that the width of the baffle seems spec'd carefully by designers. Does the height matter as much? specifically below the mid in an MT? I'm wondering, because of I do decide to go with Scott's design, could I make the baffle taller to accommodate a slot port and make the box shallower to keep the same volume?

[HareBrained]

Don't do a MTM for the center channel because of the lobing of the response, especially if you have MT main speakers. A third MT would work great for the center.

[Xander]

But I do have a question regarding baffle sizing, though. It seems that the width of the baffle seems spec'd carefully by designers. Does the height matter as much? specifically below the mid in an MT? I'm wondering, because of I do decide to go with Scott's design, could I make the baffle taller to accommodate a slot port and make the box shallower to keep the same volume?

As far as I know, spacing below the mid should have no audible effect on speaker response.

[cjd]

Who tunes the RS150 that high? :P I tune to 39Hz on my MTM...

I have some nice measured responses off-axis on the MTM which will tell you just why it's a bad idea to place horizontal.

I'd guess you'll hit mid 90dB at one meter... possibly on the quiet side for a teenager because by the time they've got them tucked away wherever they'll go, that'll max out around 90dB.

Sealed, cross to a sub at 80Hz, standard receiver fare works about perfectly with these.

Baffle height has some impact in a TM, but not as much. Given standard placement as most people go and you've got much bigger problems than a little change in baffle size. All relative...

C

[eyekode]

Sounds plenty loud enough for my application. What do you think of the Cryolites? And just out of curiosity, why don't you use the sub for listening material too? Any idea where you'd cross them if you did?

I think it is mostly preference. I EQ my sub with something like a house curve. I actually could dial in a flatter eq for listening to music (my BFD has more than one memory slot of course...). But I find the Cryolites fine for music at the level I listen.

I cross to my sub at 80hz. I cannot localize it. But it is between my mains...

Santa and the itch are getting to me ... I'm starting to lean toward a .25 cabinet - just seems more flexible in terms of space and fitting in wherever they may be used.

You simply cannot go low in a .25 ft^3 cabinet.

But I do have a question regarding baffle sizing, though. It seems that the width of the baffle seems spec'd carefully by designers. Does the height matter as much? specifically below the mid in an MT? I'm wondering, because of I do decide to go with Scott's design, could I make the baffle taller to accommodate a slot port and make the box shallower to keep the same volume?

Technically distance between the woofer and the bottom of the cabinet will matter. But it will matter half as much as the distance from side to side. So not so much of a big deal.

But if you have a receiver that does automatic EQ the baffle widths won't matter so much.

[eyekode]

Who tunes the RS150 that high? :P I tune to 39Hz on my MTM...

I just threw it in WinISD and took what it gave me

[cjd]

39Hz isn't flat either... it works really well near boundaries though.