System Overhaul Thread

[luvdunhill]

so, I googled that gadget.. yeah, i see why that would be the proper tool for the job.

I can try and find that weird metric thread. Am I basically looking for a threaded rod that could be cut down? The stock ones look like Delrin.

[swt61]

Steve,

I could loan you a Nova for a while...

Thanks Nate, I'll let you know once Marc has settled on what woods he's going to be using.

Marc, either threaded rod or a bolt. The bolt head could be recessed into the piece, and that would keep the rod from turning.

[luvdunhill]

in case there was doubt, CNC cut horns FTW

[n_maher]

Very cool, Marc.

[swt61]

Wow! That sure makes it simple. So the driver is fully enclosed I guess?

[swt61]

Update.

I was at Marc's this last weekend, and got to listen to the corner horns. In short they sound fantastic. Such a full, weighty sound from a single 6 1/2" driver is a real surprise. They really throw a large soundstage too, and without a narrow sweetspot. I could be very happy with these just as they are, but Marc wants to fill in some of the lower octaves. Actually the bass is there, but not in large supply.

So we set out to assemble us some 'paint by number' subwoofers Friday evening. Within 45 minutes we had both subs glued and assembled, save the outer pieces and the drivers. This guy builds a beautiful kit, that the most inexperienced hobbyist can easily navigate. The next evening we finished them off in short order, and even took the opportunity to play some 50 Hz. and 20 Hz. test tones through them. These long throw 7'' subs move some serious air through the tapped horn enclosures. I was gobsmacked at the amount of low end, visceral bass. We did find a small leak in our glue joint on one sub, and it created a different frequency note when not plugged. The pressure really was unexpected for me, Marc of coarse was not at all surprised. I'm sure he'd already calculated how far they could throw a ping pong ball at X Hz.

I believe he delivered the corner horns and subs to the painter for prep and paint before he left today for the land of Crumpets and Crowns. Then we'll finish them off with some solid Wenge trim.

Stealing your thunder again Marc, but I had to talk up these brilliant speakers.

[johnwmclean]

I love the idea of Pass driven full ranges and nice to know you're getting good initial results from the subs.

Once I have my EUVL's F5X up and running I may do something similar. What sub kits did you use?

Looking forward to seeing pics of those painted beasties.

[swt61]

I think Marc said that he got them from a gentleman on the AV123 forums. It's a one man outfit for sure, but his attention to detail is really great.

I believe he's working on a larger version with a 10" IIRC.

[luvdunhill]

Need more time to update this thread, but Steve I decided to figure a way to seal that leak and it turns out that 2 part epoxy worked very well. Now I have a small leak on the center of one of the binding posts, but it's minor. Didn't get them to paint as I want to obsess over them for the next couple weeks until we leave for Russia.

The subs do hit 20 Hz. I pushed them even harder. But, I'm running into the thermal limit and power rating of the drivers earlier than I would like. They do sound very sweet. I did some measuring at can cross them over at 80 Hz -6dB with a 24dB/octave slope at the highest, which is impressive.

[swt61]

OK, you've proved your point...a guy can get an averaged sized unit to to produce a good effect.

[luvdunhill]

OK, you've proved your point...a guy can get an averaged sized unit to to produce a good effect.

Just need a high out output stroker and 7" is plenty.

In all seriousness, I think two 7 inchers or nice 10 inch is more what I need. Wait. Hm. Too late to call a do over?

Edited March 23, 2012 by luvdunhill

[swt61]

Well as I said previously, I could always mount a panel amp on them and use them in my main, two channel speaker rig.

[deepak]

Care to share more details on the subs? People are telling me to go OB for subs that will work well with the 63s

[CarlSeibert]

Ditto. A new sub for the home theater of the absurd is a long overdue project. These sound interesting.

[Dusty Chalk]

Tritters. I missed this thread due to be being on sabbatical when it was posted. Please do post moar impreshunz.

[luvdunhill]

So, I will return a question with a question. How audible do you believe time delay is (for subwoofer integration)?

Here's one discussion:

http://sound.westhost.com/pcmm.htm

oh and also, this design is not really a OB, but a tapped horn design. And, because I'm curious, what OB was recommended? perhaps a H-frame?

[deepak]

So, I will return a question with a question. How audible do you believe time delay is (for subwoofer integration)?

Here's one discussion:

http://sound.westhost.com/pcmm.htm

oh and also, this design is not really a OB, but a tapped horn design. And, because I'm curious, what OB was recommended? perhaps a H-frame?

Yup one recommendation for H-frame. There isn't a whole lot of info out there for stuff that will work well with the ESLs.

[Dusty Chalk]

So, I will return a question with a question. How audible do you believe time delay is (for subwoofer integration)?

Me, personally, I think it's crucial. I tuned my Sunfire Jr. by hand...er...by ear, rather... when trying to integrate it with my Spendor S3/5's. I really want that again.

[luvdunhill]

For whatever reason, I'm intrigued about this problem Deepak. Budget? Do you want stereo subs? Is a separate amp (not a plate amp) okay?

For HT, I'd definitely recommend these TH. For ESLs, I'm not sure I would, due to delay issues. In fact, this is one of the main reasons I'm not sure how they will integrate with my horns. I'd assume that whatever would work for my horns would work for the ESLs.

The reason I ask about group delay, phase, etc. is that the reason that many people go with ESLs is to avoid these issues that they believe to be paramount. Adding a sub and maintaining these goals is difficult.

Edited August 8, 2012 by luvdunhill

[swt61]

So, I will return a question with a question. How audible do you believe time delay is (for subwoofer integration)?

Here's one discussion:

http://sound.westhost.com/pcmm.htm

oh and also, this design is not really a OB, but a tapped horn design. And, because I'm curious, what OB was recommended? perhaps a H-frame?

That's somewhat of a loaded question, because bass is so over accentuated in much modern music and music playback systems, that so many younger people have no idea what properly reproduced music should sound like. However, among the more discerning I think delay is pretty audible in all but the lowest frequencies.

[deepak]

For whatever reason, I'm intrigued about this problem Deepak. Budget? Do you want stereo subs? Is a separate amp (not a plate amp) okay?

For HT, I'd definitely recommend these TH. For ESLs, I'm not sure I would, due to delay issues. In fact, this is one of the main reasons I'm not sure how they will integrate with my horns. I'd assume that whatever would work for my horns would work for the ESLs.

The reason I ask about group delay, phase, etc. is that the reason that many people go with ESLs is to avoid these issues that they believe to be paramount. Adding a sub and maintaining these goals is difficult.

Marc, I don't have a set budget in mind. I guess under $1000 in parts (not including the crossover)?

I know I have an uphill battle and may forgo the sub idea altogether. Linkwitz's H-frames look interesting to me, and those Peerless subs aren't very expensive, so if it sucked I wouldn't be heart broken: http://www.linkwitzl...x-proto.htm#PW1

As for stereo vs mono, I was thinking about initially starting with 1 then maybe going for a pair if I wasn't satisfied. I haven't thought about the amps for them yet. Mostly trying to wrap my head around designs and the math.

I am definitely not doing this to get more boom, I want subs that "disappear". I don't even need a ton of extension... 35 Hz will be fine with me.

[swt61]

It's really hard to find a dynamic driver fast enough to sound right with planar speakers.

I've wondered if turbine style subs might be the solution, but they don't seem to have gone anywhere.

[luvdunhill]

I agree. But most subs fall into two categories, sealed and ported. I tend to think that these other designs might prove to be less problematic. Just an intuition though but one I'd like to confirm.

[CarlSeibert]

In my case, the mains in that room are horn-ish (quarter-wave pipes), which made me think these might do well with them. Well, one of them. Space constraints put stereo out of the question.

[skullguise]

If you just want some extra extension with speed, Deepak, what about investigating the concept of multiple smaller drivers? I remember some subs from the 80's (Audio Pro, maybe?) that used 4 x 6.5" drivers, and sounded very fast and tight, even without huge air movement, to my ears..... With a plate amp with level and variable phase, it may work well.....