Subs were a success, now the mains

[kgveteran]

Here are some pics of my Quad Adire Tumults.I'm in the process of upgrading amps from mono Adcom555's to mono QSC 1450's.I use a BFD to tame room modes and a Marchand BASSIS to counter the sealed rolloff.

I have out done my poor mini monitors as far as output.They hang in there to about 90db and then they start to give out.My next project is a nice three way using twin 6.5 woofers one inch tweeter and a five inch midwoofer.Kindof like the Aerial Acoustic CC3.

BTW the cabinets were made by Chessis woodworks in Rochester NY.They are 2" thick MDF on all sides incuding the massive internal brace structure..Combined weight of drivers and cabinets.....700lbs. No joke, I just recovered from a double hernia operation, that was after shlepping them all over the room using TrueRta to get them situated and flat.I got the scares to prove it :

[KJP]

OMFG! 8O 8O 8O 8O

Nice :T

[Bent]

Where dis you go to get a "single" Mini? or do the front three have three sisters near the rar of the room?

[ThomasW]

Sub look good, seem like I've seen them before....

How about putting the mains on top of the subs? That would take care of the problems with reflections off the top of the cabs.

[kgveteran]

The single mini has a sister in the back of the room for an ES channel (single).

I tryed them out in the room more but the sound seemed off.I ended up with their positions where TrueRta was the smoothest and the imaging was back.I would never have thought that being against the back wall would give better imaging that out in the room but I was wrong.

You may have seen these pics over at AVScience forum, I'm a member there with the same screen name.

[Brian Bunge]

So what drivers and design are you using for your new 3-way speakers?

[kgveteran]

I had looked a a few.One was by Audax.It was a center channel kit.183.00 for the parts and I'd build a cabinet.I like the twin 6.5" woofers.I would like to get back to an 80hz xover rather than the 100hz i'm using now.

Vifa also has some kits.I've alway like the vifa textile dome tweeters.Their 6.5" woofers are used by quite a few companies.All the schematics are published so building their xovers would save a couple bucks.

I would like to see some real headroom out of my LCR.Listening at 90db requires at least 105-110 peaks.I know that sounds loud but it is never sustained.Thats all it takes is one good peak to distroy the moment.Thats why I overkilled the crap out of my subs.I got tired of hearing the drivers fail.Now that they are covered I'll shop around.

If you can suggest any kits like this I'll be glad to look around.I'll be selling off some amps and buying other ones so theis project is new and I probably wont be building anything for some time.The subs kicked my wallet hard and the family wants to start eatting again (LOL).

[Brian Bunge]

Well, since I see that you have a projector and don't have to worry about putting a speaker on top of a TV I think you'd be hard pressed to find a design much better than this one. The tower design isn't finished yet, but the center has several different designs currently posted. You could always build 3 identical towers as well if you have enough space under your screen to accomodate a tower design for a center.

http://htguide.com/forum/showthread.php4?t=15323

It uses the new Dayton RS drivers from PE, and from all the testing and initial designs posted on the various forums, appear to be great performers, especially for the money. If you don't mind sourcing the crossover parts I'd bet you'd have a much nicer speaker than anything using the Audax or Vifa drivers. Also, with the fact that the Audax drivers will not be available for much longer I don't know I'd want to use them unless you bought extras just in case you have any failure issues.

I'm probably going to build that center channel (with a larger cabinet for lower Q) to go with my 3 way towers as I doubt I'd be able to build a full on center version of that tower.

[kgveteran]

Why was there such a concern to drop the frequency the tweeter was producing ? Was the mid in that design having a problem with the upperlimits of it operating range.

My thought was a simple (ya right, simple) 700hz-2.5khz . Now to find drivers to fit the bill.Thanx for the heads up on the audax stuff.

[Owen Bartley]

Quad Tumults, damn.

That might just be the craziest HT sub setup I've seen (short of the 12 Shivas and some IB installations). Congratulations sir! I tip my hat to you.

[GrahamT]

Welcome to HTG Owen,

I'm from the Toronto area too. Every once and a while myself and other DIYers in the Toronto area get together to share our projects. You should come sometime.

[cjd]

Why was there such a concern to drop the frequency the tweeter was producing ? Was the mid in that design having a problem with the upperlimits of it operating range.

It has to do with keeping the drivers operating in the range where they don't have bad harmonic distortion (note, this is not necessarily *audible* distortion all the time).

I like the RS150's I'm using crossed at 2100Hz. I think they still add an edge of harsness (for example, they're more harsh on some particularly harsh sections than the RS180/RS28A combo crossed at 1600Hz). Trying to get things working where they work best, rather than trying to get things to work where you have arbitrarily chosen them to work.

Paper/poly cones often smudge the distortions (and harshness issues) that are clearly apparent in metal cone drivers. Many things. Dig around and read some of the longer threads/older posts around here and you'll pick up a LOT of this information.

It is simply one approach to the hobby, to picking where to cross, etc.

700Hz is pretty high (IMO), by the way. I would stick to 300-400hz at the most. Keep the range where you have the advantage of a vertically aligned TM working fully, not compromised by horizontal comb filter issues.

C

[Owen Bartley]

Welcome to HTG Owen,

I'm from the Toronto area too. Every once and a while myself and other DIYers in the Toronto area get together to share our projects. You should come sometime.

Thanks Graham, I noticed some references to a Toronto DIY meet in one of your other posts I think and I was pleasantly surprised to see that there was one. I'd love to come and take a look at least the next time.

[kgveteran]

I really like the two and a half way design of using a WTW with both woofers operating the bass region and one of the woofers choked off at about 200hz. I never cared for the sound of the WTW with both woofers working the same frequency above and below the tweeter.


Tweeter about 2.5Khz
Woofer above the tweeter 20-2.5Khz
Woofer below the tweeter 20-200hz (just to reinforce the bass)

My thought is to biamp with a stereo B&K ST-140 and give the twoway one channel and the second woofer the other channel.I have three B&K's on hand for the front LCR.I can just "Y" into the B&K for each channel.

Thanx for the comments about the Tumults.I really worked hard on this project to "NOT" build another subwoofer anytime soon.I think the best part was to draw the plans and then take them to a cabinet maker.Those guys laugh at how easy these projects are.And then laugh at how much the cabinets weigh with 2" MDF.Each cabinet cost 350.00 including materials.


My advice to anyone who doesn't cut straight lines is to get in touch with a small woodworking shop and let them at it.I ordered it on a tuesday and picked it up the next tues.Chessis woodwork Rochester NY.

[ThomasW]

Here's a suggestion based on the dispersion characteristics of each design...

2.5 way = TMM
2 way = MTM

Also it's a good idea to use a lower XO point with a MTM given the spacing of the midwoofers.

You might want to consider a MTMWW. That way you aren't stressing the midwoofer trying to get good output down to 20Hz. Though the idea of mains with output that low seems a bit redundant when there are 4 Tumults in the room.

[cjd]

Are we talking horizontal cabinets for sure here?

If so, I just don't know how you can do better (for the dollar) than the WTMW previously mentioned (Dayton RS stuff - RS225/RS150/RS28A) in sealed enclosures. The dispersion characteristics of the TM vertically just can't be beat, though a 2.5 TMM wouldn't be too bad.

Or, of course, another similar project.

My HT may eventually get slightly smaller variants (RS28/RS125/RS180 pair).

But, take your time exploring the options.

The other thing to remember - if you're not doing the design work yourself and you want to do something that's not already designed, make sure you can do good measurements.

C

[kgveteran]

The 20hz on the mains are just a number.I use bass manegement to cross them over at 100hz.I found that in their new position they are flat out to 100 so I let them do it.

I prefer 80hz but my little 6.5" woofers don't. With the subs infront of the LCR there isn't a location problem as far a locatability (new word ).

[cjd]

I would push for a 50 or 60Hz cross then. :P

You talking vertical or horozontal?

[kgveteran]

I would like to do three horizintal LCR's. I would do a Aerial Acoustic CC3 clone. I like the vertical TM and flanked by woofers.If the woofers flank then they need to be xover lower than the vertical design.

I'll take suggestions using my three B&K ST-140's. 100wpc is not alot, but they sound sweet.Biamping each LCR with one B&K may give you guys some more idea's.

[cjd]

I find 40W more than sufficient. *shrug*

WTMW only restricts low point a little. Other "rules" of design tend to push it low enough anyhow, unless you choose to cross to the tweeter really high.

C

[ThomasW]

Posted by kgveteran on AVS.....

I think the moderators suck over at htguide. I was ready to get into some design thoughts and they stick their nose in all over.The one guy tommie jumped all over me about Marchand electronics.OK...I'm all better now...