Need some perspective - 2 way or MTM kits

[gaglers]

I think I need some perspective from the wealth of expertise on this forum. I have been reading and researching for a while and I'm having trouble deciding on a project. I'd like to build some speakers that will work in our home theater but also enjoyable for listening to music. The HT currently consists of an Audax center channel I built approximately 15 years ago, 2 15 inch Ultimax subs sealed, in-ceiling AT surround speakers, and 20 year old JBL P30s I plan to replace. These will be driven by a Marantz sr5008, so I can't go below 6 or 8 ohms. I also need to keep the budget around $500 or less. The speakers will sit on a shelf so towers are out.

I'm excited to return to speaker building after a long hiatus, and hope to build some new mains with striking clarity in the upper end, a smooth warm sound and tight punchy bass. I have great access and experience with woodworking in electronics, but I'm far from an engineer and definitely plan to rely on the expertise of those with more of a head for it. I was all set to order the Seas Idunn kit, but then I found Matt Sobie's MTM blues kit, Jeff Bagby's mandolins, and several others. This all started when I heard my friend's ML Theos panels, then auditioned some two-way monitors from B&W and Monitor. I was reminded that the use $1,500 speakers did not sound a lot better than the Vifa 2 way monitors I built 20 years ago.

So after months of research I find myself more confused and almost questioning whether to invest $500 on a kit such as this, almost... I know this question will invite a lot of opinions and personal preferences but I welcome any perspective you can offer, particularly if you have any experience with the kits mentioned above in this price range. Thanks in advance.

 

[Inductor]

Do you know most speaker kits? Speaker Kits https://www.madisoundspeakerstore.com/speaker-kits/

 

[Michael92]

The way I look at it is...MTM is more than likely better. You are putting less stress on each woofer during intense scenes and therefore are able to keep a little more clarity.

The hairy area is...If you are buying a MTM kit for $500 and a TM kit for the same $500 I'd put cash on the later sounding better overall.

So the real question is are you prepared to spend more to get the same quality drivers? Hopefully that made sense.

Also, I read that if you do a MTM setup the two mids will sound like they are coming from the center of the box by the tweeter. No idea if that is true..I am hoping someone can chime in on that. <----Really unless someone else has a fact on this ignore it...

 

[nannoo]

I'd go for a basic WT over WTW (or MTM if you like).
Reasons:
$500 is a tight budget
keeping impedance acceptable is a lot easier with single woofer
will allow decent quality drivers

When you say woodworking skills, do you mean we can factor out costs of cabinets beyond raw material?

 

[nannoo]

Also, with that kind of budget you could consider a nice 3-way, on the basis that cabinetry isn't going to cost you too much and you're happy not to have mundorf silver/gold/oil caps

 

[ODougbo]

MTM's are perfect for HT if you can set them up high enough.
Been working a few sets for a couple of years now, all 4 ohms though.

 

[gaglers]

This is really helpful, and I've been reviewing kids on both Madisound and Meniscus for quite a while. I have long coveted the Scandinavian kits and would love to resolve this question by ordering the Froy, but that is 4 ohm and financially unreasonable for me. I should add that I've always been interested in working with the D'Appolito design based on everything I've heard about its imaging and efficiency, but most kits are 4 ohm. I guess part of my hope is the reviews of less-inexpensive high-performing drivers from HiVi, Dayton, SB, etc. I know we get what we pay for, but I'm hoping the HiVi L6 woofers and SB or Dayton RSVP tweeters offer a bargain and can perform comparably to more expensive drivers. Is that a reasonable expectation?

 

[LineSource]

1) Excellent Speaker! Under Bugdet!
TM alignments are more coherent than mixed midrange sources from MTM. Most MTM designs produce lobing around the Xover, which also distorts the soundstage image. A single 6.5" midrange like the SB17NRXC35-8 has about 89db sensitivity. Since your amp requires near 8 ohm loads, both the 8-ohm tweeter and (M+M) series resistance will limit the MTM efficiency to ~91db with twice the M cost and box size.

A proven, well reviewed TM like Jeff Bagby's Mandolins using SB Acoustics drivers will easily meet your budget. You could gut the JBL P30 cabinet, or construct/purchase a new 1 cuft box which can support both ported and sealed alignments. You can purchase Jeff's kit for $350/pair, or purchase separate parts for about the same cost. Unless you have a collection of Xover parts, most kits are a reasonable deal. (DIY Speaker Components | Replacement Speakers | and Speaker kits from Meniscus Audio Group) I like the uncoated cone SB17NRC35-8UC version.

SB, SB17NRXC35-8-UC $63
SB, SB29RDNC $61
crossover ~ $40

2) "I'm going to ROCK your WORLD!" for about $650 + boxes (JBL P30 box not wide enough)
EconoWave speaker designs are very popular for HT. SERIOUSLY! Give this option some study and thought. Effortless Dynamics! Waveguide 90-degree horizontal controlled directivity covers family couch. 40-degree vertical directivity removes most floor/ceiling bounce. HEY, you only live once, and many HT are excited with Econowave.

The Fusion-12: Tempest uses the Eminence Delta Pro12-A woofer due to its high 97db sensitivity and very linear response. The Tweeter is the Denovo DNA-360 compression driver mounted to the SEOS-12.
--14.5" wide x 26" tall x 14.25" deep box with double thick baffle
--37Hz ported, up to 18Khz from wave guide compression driver.

Fusion-12 DIY Sound Group

 

[eriksquires]

Hmmm, I would say keep it simple. Also, how much shelf space do you really have?

If you wanted to "hack" a kit idea a little bit, you could start with the Scanspeak Resiscovery Kit. It's a little more but totally worth it.

I am using the 4 Ohm version of that woofer in an ported enclosure. The enclosure is rather large, but wow, if you want full room filling clear bass you'll have it.

The plans are for a tower, but you just need to match the internal volume and port specs. If you are going to insist on using a subwoofer, you can redesign this in a sealed enclosure for about half of the volume. Here's a pic of a similar design, for you to get an idea of the size of the ported version so you can get an idea.

 

[ODougbo]

You won't be disappointed with D'Appolito designs, even with the limitations.
Here's a best in class woofer: Anarchy Woofer DIY Sound Group
Buy 8, 3 pairs for up front and use a pair for a sub-woofer. Crystal clear mids and rock solid bass. The boxes are un-complicated and easy/fast to build.

This tweeter is mesmerizing, and used commonly used with the Anarchy.
Dayton Audio RS28F-4 1-1/8" Silk Dome Tweeter

This is really helpful, and I've been reviewing kids on both Madisound and Meniscus for quite a while. I have long coveted the Scandinavian kits and would love to resolve this question by ordering the Froy, but that is 4 ohm and financially unreasonable for me. I should add that I've always been interested in working with the D'Appolito design based on everything I've heard about its imaging and efficiency, but most kits are 4 ohm. I guess part of my hope is the reviews of less-inexpensive high-performing drivers from HiVi, Dayton, SB, etc. I know we get what we pay for, but I'm hoping the HiVi L6 woofers and SB or Dayton RSVP tweeters offer a bargain and can perform comparably to more expensive drivers. Is that a reasonable expectation?

 

[gaglers]

I meant to add that the budget is not hard ceiling of $500 and I am not factoring in cabinet costs, I can absorb MDF & hardware. I'm also not that concerned about bass volume, I'm running the two Ultimax in four foot sealed enclosures driven by a Behringer amp, their response is both musical and impressive. I had looked at the rediscovery kit, it looks great as well and I'm most interested in the picture you posted with the ribbon tweeters. I've never worked with ribbon tweeters and was just thinking about domes, should I consider a ribbon kit using Fountek or Airborne? I heard a friend's Martin Logan monitors with the folded ribbon and they were impressive.

 

[gaglers]

I forgot to say, I love those slot ported MTMs ODougbo posted and have a pretty open shelf space to adapt as Erik suggested. I suppose my perfectionism is coming out, and I want to get the most out of my effort.

 

[eriksquires]

I meant to add that the budget is not hard ceiling of $500 and I am not factoring in cabinet costs, I can absorb MDF & hardware. I'm also not that concerned about bass volume, I'm running the two Ultimax in four foot sealed enclosures driven by a Behringer amp, their response is both musical and impressive.

I had looked at the rediscovery kit, it looks great as well and I'm most interested in the picture you posted with the ribbon tweeters. I've never worked with ribbon tweeters and was just thinking about domes, should I consider a ribbon kit using Fountek or Airborne? I heard a friend's Martin Logan monitors with the folded ribbon and they were impressive.

The Mundorf AMTs are absolutely delicious sounding and as another DIYer has measured, incredibly low distortion, but they are also the single most expensive part of the kit and blow your budget all by themselves. They're like everything good about Berylliums without ringing anywhere and to my ear, even more natural sounding. I have not done a major survey of drivers, but I'm so incredibly happy with how these turned out I feel no need to do so.

On the other hand, the Scanspeak 7" drivers are the least expensive part of that speaker which is why I am recommending you look for kits built around that. Listening to movies it took me a week to realize my subwoofer was off. Until I played Godzilla and realized the windows weren't rattling. For everything in music though, there's nothing they miss.

I would suggest however, that your learning experience will be half of the pleasure. Don't go for perfectionism yet. Go for done! You'll learn a lot along the way, including that your tastes may not be what you thought they were when you started.

Best,

Erik

 

[chrisb]

you might want to give this one some consideration as well

with dome tweeter

Creative Sound - Product Details

and ribbon

Creative Sound - Product Details

 

[ODougbo]

What I'm seeing is a need for 3 medium size mtm's, $166 each, they must be 6 - 16ohm.
This is the direction I'd head:
2 sf 6.5" 4ohm 2x30 = $60
SB 29 RDC =$51
$55 for xo parts

https://www.madisoundspeakerstore.c.../silver-flute-w17rc38-04-ohm-6-1/2-wool-cone/

https://www.madisoundspeakerstore.c...b-acoustics-sb29rdc-c000-4-ring-dome-tweeter/

I've been taking the dust caps off and making phase plugs, several ways to make them easily.
Maybe later today i'll put one together and measure (active).

These are incredible sounding HT speakers, the power and clarity is amazing.

 

[norman bates]

My buddy got into using felt dustcaps.
I'm thinking the 8" sf would be as good as my flatish 6.5's if the dustcap was removed.

I'd love to see a before and after freq graph for the phase plug vs dust-cap.
Can you make a bullet shaped phase plug ?

In the white, that's a nice looking speaker there.

Is the rendition better when both crossed at say 100hz ?


Norman

 

[eriksquires]

I meant to add that the budget is not hard ceiling of $500 and I am not factoring in cabinet costs, I can absorb MDF & hardware. I'm also not that concerned about bass volume, I'm running the two Ultimax in four foot sealed enclosures driven by a Behringer amp, their response is both musical and impressive. I had looked at the rediscovery kit, it looks great as well and I'm most interested in the picture you posted with the ribbon tweeters. I've never worked with ribbon tweeters and was just thinking about domes, should I consider a ribbon kit using Fountek or Airborne? I heard a friend's Martin Logan monitors with the folded ribbon and they were impressive.

Hi Gaglers, I've created a new thread where I have posted the crossover for a 2 way which uses the Dayton AMT, much cheaper. Take a look here.

Best,

Erik

 

[chrisb]

gaglers - at the risk of a flame war, if you want to get the most out your efforts, think high quality plywood ( Baltic Birch, Apple, etc) rather than MDF - the labour time is about the same, and there are many who consider MDF a less than ideal material sonically.

 

[gaglers]

Thanks, I had not considered that. I had planned on MDF as I understood that to be the standard, but from a woodworking/finish perspective I might prefer laminate plywood.

 

[chrisb]

Trade & local generic terminology for materials can get a bit confusing once you start talking anything but MDF . There's probably far more variation in quality and pricing among plywoods so than MDF. Not all birch or maple veneer faced plywood scare created equal - but the most important observation I can make based on 23yr in the commercial millwork trade is- avoid the Asiatic imports except for pre-finished birch for kitchen cabinets, etc, or the "meranti" types for non critical substrate /carcasses when to be skinned with a thin MDF prior to laminating with plastic or veneers.

This has been discussed countless times over the past dozen or so years, with, surprisingly no final consensus


To be clear, I'm talking about the high ply count -11 or even 13 for nominal 3/4" / 18mm sheets- generally close to void free. There are numerous NA domestic trade/brand names for this type - a common one being "Apple-ply"
I happen to use a product by Murphy Plywood of Oregon, and with the current exchange rate on the Canadian - I'll call it "loon-so" ( as in peso) - a 4x8 ft sheet of the 18mm is over $100 Cdn . That's at least 30% more than when I first started using it after seeing a marked deterioration in QC on the Russian sourced 5x5 Baltic birch I'd used previously.