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Lilmike's Cinema F-20 - Page 35

post #1021 of 1695
In my case, it kills two birds. One, I really like the Rythmik subs and I'd like to keep using them. They need more output to stay though. Two, I just wanna!

Bracing - similar to what you've done, just perhaps a little bit more of it. I never was a "follow the recipe" kind of cook! I'll have to look at those threads. Got a link?
post #1022 of 1695
I used mine as a shelf for my entire front stage for months. And I was pushing the tempests with 650 watts a piece, absolutely no problems. The small brace lilmike added in the latest edit is all that you'll need if at all.
post #1023 of 1695
Thread Starter 
Quote:
Originally Posted by paulspencer View Post

In my case, it kills two birds. One, I really like the Rythmik subs and I'd like to keep using them. They need more output to stay though. Two, I just wanna!

Bracing - similar to what you've done, just perhaps a little bit more of it. I never was a "follow the recipe" kind of cook! I'll have to look at those threads. Got a link?

Think it was this one, but it is not a small thread. Lotsa good bits of info in there though, plenty of actual building and testing.
post #1024 of 1695
Thread Starter 
Quote:
Originally Posted by superedge88 View Post

What driver would be recommended for a narrow f-20? I appreciate any help, I'm trying to integrate two horn subs into a built in shelving/entertainment center.

Oops - missed this. Sorry.

Sorry, don't really have any suggestions. Look for a lowish Qes, a fairly high Vas, and a low Fs, around 20 Hz. I have not done a lot of modeling of narrower cabinets. Do you have a width in mind? I can post a model for you.
post #1025 of 1695
Quote:
Originally Posted by lilmike View Post


Oops - missed this. Sorry.

Sorry, don't really have any suggestions. Look for a lowish Qes, a fairly high Vas, and a low Fs, around 20 Hz. I have not done a lot of modeling of narrower cabinets. Do you have a width in mind? I can post a model for you.

I was hoping for about 18" wide. I Don't know much about the woofer specs needed as far as your recommendations, so I am at the mercy of those more knowledgeable than I.
post #1026 of 1695
Thread Starter 
Quote:
Originally Posted by superedge88 View Post

I was hoping for about 18" wide. I Don't know much about the woofer specs needed as far as your recommendations, so I am at the mercy of those more knowledgeable than I.

No worries.

At 18", that is 16.5" internal. A 15 will still fit, but things are getting snug and compression is getting a bit high. Let me take a look at a few things.

Edit...

OK, at 16.5" internal, 15's definitely look better than 12s. Compression is higher than I'd like, but not that high, a driver with a strong cone should be fine. The JBL GTO1514 car driver looks pretty good, and is priced right at around $125 shipped if you shop a bit, street is closer to $150. Not at all bad for a cast-frame 15 with 14.5 mm of xmax. The new Kicker Comp 15 (single 2-ohm) also looks OK. The Dayton Titanic looks OK, as do the usual suspects, the DVC and the Reference HF 15, but their cones may not be as tough as the car drivers. No experience with any of these firsthand - all based on specs provided and modeling alone.
post #1027 of 1695
lilmike: I built an F20 last fall, which I have not used yet as the focus on the winery was switched to the outside. Now that I am getting back to the speaker making; I see there is talk of extra bracing. Is this extra bracing just for peace of mind, or has additional use and/or testing show that it is needed? I am getting ready to build three more F20s; as four of them will be put together under a 180" acoustically transparent screen that conceals 4pi LCRs. I just don't want to regret not having done the extra bracing if it is shown to be needed. Thanks in advance for the feedback.
post #1028 of 1695
F20 ....





Building with some cheap formply that ended up costing the same as MDF and it's much lighter which is a huge plus. Quite surprising how light this thing is as a result. Quite easy to assemble lying on the side, constructive adhesive, screw fixing as clamps. The other side will go on last and I'll cut up some braces before it goes on. Should be pretty simple, using some offcuts angled with the mitre saw. There will be a bass GTG at my place soon to compare a pill of bass boxes. TD18H sealed, some Eminence Magnum 18" drivers, my T20 Rythmik tapped and F20.
post #1029 of 1695
Thread Starter 
Quote:
Originally Posted by dutchswan0311 View Post

lilmike: I built an F20 last fall, which I have not used yet as the focus on the winery was switched to the outside. Now that I am getting back to the speaker making; I see there is talk of extra bracing. Is this extra bracing just for peace of mind, or has additional use and/or testing show that it is needed? I am getting ready to build three more F20s; as four of them will be put together under a 180" acoustically transparent screen that conceals 4pi LCRs. I just don't want to regret not having done the extra bracing if it is shown to be needed. Thanks in advance for the feedback.

Wondered where you'd been...

The pieces of bracing that I have suggested can be retrofit into existing cabinets by working through the driver access panel, the driver hole, and through the mouth. I did not really feel the need for it when I designed the cabinet, and noticed no real issues with mine during testing and use. I presented it as a suggestion about how to apply effective bracing (that can be retrofit into an existing cabinet) for those that are more concerned than I am.

Certainly, the F-20 can be improved upon, I'm not denying that at all. I felt it was more than adequate to share without the added complexity of bracing. At what point will the audible results of the additional level of effort required reach diminishing returns? That's for each individual builder to decide.
post #1030 of 1695
Bracing is easy to add with offcuts:



There are all kinds of opinions about bracing. Some even feel there should be no spans greater than 4"! I prefer to do the most bracing that can be done easily. The method I use here is quick and easy. Simply overlay an offcut, draw on the angle and cut with the mitre saw. Dead easy.

This one is now assembled, it just needs a hatch, drivers and cabling installed. Built with 17mm formply which is very light. Two people could lift this easily. One person can move it around on the corners.
post #1031 of 1695
Quote:
Originally Posted by paulspencer View Post

There are all kinds of opinions about bracing. Some even feel there should be no spans greater than 4"! I prefer to do the most bracing that can be done easily.

This should be just enough bracing to ensure the F20 is still standing after the house has already collapsed!
post #1032 of 1695
Well, I've now had a chance to listen. Initial impression is that it had a pro sound style of chunkiness, turns out the box is nice and solid also, happier with it now. After a quick integration it now works quite well and disappears in the system. This will be featured in a little bass GTG soon, compared to my Rythmik tapped horns and some other bass bins. Will be fun.

Initial impression is also that it doesn't really like to run high. Others may differ, but I tend to think the best use for these beasts is to use one monster for the low HT stuff and cross to a pro woofer. I also do that because I have to with my Synergy horns that require woofers running up to 220 Hz or so. A big peak in my room at 44 Hz means a sealed pro woofer will get down low and a crossover around 44 Hz works well, I can use the high and low pass filters to coincide with the 15 db peak.

I'll probably have more to say about it when I've spent more time with it. Of course, this is a bit of a different F20.
post #1033 of 1695
here's mine; going to pick it up on saturday. 12 hour road trip for a sub.

build thread is here: http://forums.klipsch.com/forums/t/159382.aspx

post #1034 of 1695
I think you will be impressed. It definitely has some thump.
post #1035 of 1695
Quote:
Originally Posted by thaddeussmith View Post

here's mine; going to pick it up on saturday. 12 hour road trip for a sub.

build thread is here: http://forums.klipsch.com/forums/t/159382.aspx


Nice wood work and if thats MDF its gonna weigh a ton.....
post #1036 of 1695
heh.. it is indeed MDF and weighs around 200-250 on the scientific "oh sh*t, my back" scale. I wanted to make sure that no tipping risk existed with my first kid coming around the corner, pets, etc.

I have no plans to leave this house any time in the next 30 years, so once it is placed and set, we're good to go - so excess weight wasn't much of a factor.
post #1037 of 1695
lilmike (or anyone)...

I am thinking about purchasing HuskerOmaha's two F20s, as he is getting different subs and will be driving past my house anyway getting from Omaha to ED in Newton, IA. I have a couple of questions:

(1) As you may remember, it is my plan to employ four F20s under our 180" screen. Due to aesthetic considerations, these four subs will be grouped together, or spaced as much as can be under the screen (in the wall). Would there be any issues with two of the F20s having the 390HF, and the other two having the MFWs that are currently in HuskerOmaha's F20s?

(2) If there is an issue with mixing drivers, I can purchase Husker's F20s without the drivers, but then there is the question as to whether or not the hole allignment is the same betweetn the MFW and the HF.

Thanks in advance for any guidance that is provided!
post #1038 of 1695
Thread Starter 
Quote:
Originally Posted by dutchswan0311 View Post

lilmike (or anyone)...

I am thinking about purchasing HuskerOmaha's two F20s, as he is getting different subs and will be driving past my house anyway getting from Omaha to ED in Newton, IA. I have a couple of questions:

(1) As you may remember, it is my plan to employ four F20s under our 180" screen. Due to aesthetic considerations, these four subs will be grouped together, or spaced as much as can be under the screen (in the wall). Would there be any issues with two of the F20s having the 390HF, and the other two having the MFWs that are currently in HuskerOmaha's F20s?

(2) If there is an issue with mixing drivers, I can purchase Husker's F20s without the drivers, but then there is the question as to whether or not the hole allignment is the same betweetn the MFW and the HF.

Thanks in advance for any guidance that is provided!

Never measured the RSS390 in an F-20, so I have to say that I don't know how they'll play together. The horn should largely dictate the response though - should not be too much of an issue.
post #1039 of 1695
I had the same thought - that must be heavy! Antripodean and I used cheap formply. It's very light for the size, if not for being so big the average person could lift it. Standing it up vertical it's not difficult for one person to walk it around, on carpet at least.
post #1040 of 1695
I asked Bill whether mixing an RSS in a THT with an MFW in another THT would be OK, and he replied that "response is almost identical" - a THT isn't an F-20, but similar design, so by the commutative property, you'll be fine.

I missed the boat on the MFW deals, so I ended up doing one with an RSS and the other with the recommended DVC driver. No audible or measurable difference for those two for me.
post #1041 of 1695
it's home. it's big. it's HEAVY. but even after just a quick and dirty audyssey calibration (it was 10pm by the time i got things setup) and the gain on my oAudio 500w set to only 1/2 way - it's awesome
post #1042 of 1695
Quote:
Originally Posted by dutchswan0311 View Post

lilmike (or anyone)...

I am thinking about purchasing HuskerOmaha's two F20s, as he is getting different subs and will be driving past my house anyway getting from Omaha to ED in Newton, IA. I have a couple of questions:

(1) As you may remember, it is my plan to employ four F20s under our 180" screen. Due to aesthetic considerations, these four subs will be grouped together, or spaced as much as can be under the screen (in the wall). Would there be any issues with two of the F20s having the 390HF, and the other two having the MFWs that are currently in HuskerOmaha's F20s?

(2) If there is an issue with mixing drivers, I can purchase Husker's F20s without the drivers, but then there is the question as to whether or not the hole allignment is the same betweetn the MFW and the HF.

Thanks in advance for any guidance that is provided!


In case you need them, I've got two unused MFW's that are sitting in my garage. I'd make you a good deal.

Jim
post #1043 of 1695
Quote:
Originally Posted by zora View Post


In case you need them, I've got two unused MFW's that are sitting in my garage. I'd make you a good deal.

Jim

Zora check pms....
post #1044 of 1695
Lilmike...I am trying to make my wall that conceals all of my speakers and sub not protrude 36" as it is currently designed. I thought I once read that the F20 can have the horn come out of the side on the wide side stead of the narrow side. This would shave 10" off the intrusion of the wall into our ballroom. Will doing that have any affect on the horn's performance?
post #1045 of 1695
Thread Starter 
Quote:
Originally Posted by dutchswan0311 View Post

Lilmike...I am trying to make my wall that conceals all of my speakers and sub not protrude 36" as it is currently designed. I thought I once read that the F20 can have the horn come out of the side on the wide side stead of the narrow side. This would shave 10" off the intrusion of the wall into our ballroom. Will doing that have any affect on the horn's performance?

Should not have a significant effect at all. Just make the area of the cutout equal to the area of the mouth.
post #1046 of 1695
Ok, I read all 35 pages of this thread to make sure I didn't ask something that was already covered. I have to say this is an amazing community for sure. Thanks lilmike for giving all of this away and everyone else that participated for giving all of the great advice. It's kind of funny that so many have already moved on and I'm just now finding out about this and considering building one. I bought the plans for the THT and after reading them and actually measuring my area there's no way I could fit a cab that wide up there. This one will fit with everything else and work out just great for me. My WAF isn't a problem as I'm already using Cerwin Vega E-715's for mains and this is only a foot or so taller than those are. It will be tight but will work just fine.

That said, lilmike what do you think about using a Titanic 15" and something like an inuke1000dsp to power it?

I only saw that driver mentioned in one other post but he was looking to narrow the cab and you said that driver was ok for his use but I was wondering about it's use in general for a standard size cab. Would there be any increased spl with the extra xmax and the higher wattage or are the gains so negligible that it isn't worth the extra expense?

I could go with the rf390 and a 300-500 watt bash plate just as easily but I was kind of hoping for something major with my first diy. If there aren't any reasons to go like that I will just build as suggested in the first post. The inuke 1000 gives up 300 watts x2 in 4ohm and supposedly 1000 bridged 4ohm mono. I'm sure the bridged rms is closer to 500 and by using the dsp I can save the $125 on a minidsp to use for the hp. Either way I'm sure it will crush the month old Klipsch RW12d I just got. It seems all it did was spark my curiosity in the hobby again and now I'm ready for something more substantial. I got it off the newegg $299 sale though so I'm sure I can unload it without a loss.

Hopefully I can start cutting wood next weekend... Thanks for everything so far and in advance for looking at this combo for me. If it's not worth it, what do you think the best combination is out there right now to use in this?

TIA.
post #1047 of 1695
Lilmike is going to say something to the affect that it is a bandwidth limited enclosure and that if you use a higher wattage driver that you should still limit your output to 300 watts. To this novice, a Dayton Reference HF capable of 500W RMS is going to generate the same SPL at 300W as the MFW driver it was designed for. I am using theReference HF drivers in four F20s and am going to drive them with 700W amps....but at Lilmike's suggestion, I probably won't put much more than 300W through them (unless they sound better by doing so). So far, no one has measured the response of the F20 using that driver. Hope that helps.
post #1048 of 1695
I was thinking that might be somewhat the case. I figured it was worth asking to be sure. If there's no benefit I'll probably use a Dayton RSS390HF and a bash 500 watt plate (for a little headroom to keep it cool). That is unless someone can come up with a combination that actually shows any benefit.

Thanks for the response.
post #1049 of 1695
Quote:
Originally Posted by ovrrdrive View Post

Either way I'm sure it will crush the month old Klipsch RW12d I just got.

I've had the klipsch rw-12 and the rt-10d, and there is absolutely no comparison to this sub. you will not be disappointed.

Quote:
Originally Posted by dutchswan0311 View Post

So far, no one has measured the response of the F20 using that driver. Hope that helps.

i've gotten the dayton driver in mine and it is nicely integrated into my system using Audyssey, but i can still hear some issues related to my room. i'm currently gathering tools in order to measure room response and will be using a BFD to minimize those effects.

I haven't done any ground plane measurements with which to compare against the MFW, but i can tell you the combo performs very well. i'm using the oAudio 500w bash amp and had to reduce the gain to around 10-15% in order for Audyssey to set my LFE trim at -2.5. After that I only turn it up between 15-30% and it's more than enough clean bass than my room/house can handle.

lilmike did very well on this one and it is most certainly a keeper.
post #1050 of 1695
After I realized the inuke1000 is actually putting out less wattage than the bash 500 I went ahead and ordered one of the Oaudio Bash 500 plate amps. I'll hold off on the driver until it looks like no one has any better suggestions than the rss390hf. I'm sure with limited time it will take me a few weeks to be ready to fire it up anyway.
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