swissy

I thought about moving my old pair of KG 4's to my home theater. How well would these match up with my RC $ RB 25? Or should I stick with the RB-35. I want to move the RB-35's to my study, but only if the KG 4's will work well in the HT.

I think this thread has convinced me to buy the RF-25. I assume these can be set to large? I do have what I would consider a nice DIY sub. It is an Adire DPL12 in a 54L box and I am making a vented 85L box to see how I like that. At any rate, it sent out a good range and dB level. I guess what you are saying is that the room would be better served if the RC,RS-25 set to small. BTW, I already had the RS & RC planned that way. The RB and RF is all that is left to decide on. At any rate, can the RF-25 be set to large? If not, I would probably be better served by saving a few bucks and getting the RB-35.

I did contact Kyle from acoustic visions and we are working on figuring it out now. He thinks it may be the amp but I'm working on some theoretical models to see if I can figure it out. I am also testing the amp for a dc offset. This may lead to the answer. I did notice that there is a point at which I turn the gain knob up on the amp that the cone jumps about half or more of its excursion in. I slowly turned the knob until it made the jump. There was a point that just made the thing go crazy. The 20 Hz signal looked good when I did this, but the 30Hz signal had a LARGE jump. This is why I am testing for a DC offset.

I wouldnt say Im dissatisfied with the level. I did not mean to give this impression. I was just curious about what seemed to be an anomaly. I tried it again and was able to get 100% turn on the gain knob @ 20 Hz for a reading of 112 dB. However, a 30 Hz signal would bottom out at 30% gain turn. The sound is two magnets slapping together. I jumped the first time I heard it. I am positive it is bottoming out. Again, its not the level, and I know that the room acoustics will give me a bump in the response at the 30-45 Hz range. I just cannot understand why the driver would bottom out at 30 Hz and not 20 Hz. I did find that one of the tinsle leads was hitting the spider. This solves the rattling issue but not the bottoming out one. Thank you again for your help.

Here is the procedure I used: Set receiver to calibrated volume for other speakers (-30) and sub amp to 50% played 20Hz and recorded the readings. Then I moved up to 25, 30, ect. When I reached 30Hz, the sub made a slapping sound. I turned down receiver until it went away. Then turned the receiver up slowly until slapping sound came back (-41) then decreased 3dB to (-44). Then I took all of the readings from there starting over again at 20Hz. Here is my first thought after some time to think about it: The polyfill I used was the type for stuffing pillows. I then secured it, so it did not fall, with ¼ thick roll polyfill. I stuffed this between the braces and made a floor out of the roll polyfill. Hence, the polyfill sits on top of the roll style. I suppose it is possible that this is negatively affecting the volume of the box. If I model the box so that it gives a net volume of 25 L, I get a response curve that matches that of my readings. Then I check the power response and @ 30-40 Hz, it shows the displacement being limited by the driver instead of the thermal limit. This would account for the driver bottoming out at the louder levels. If you model a 25 L box, you would see a response curve with a large hump in the response. Exactly as the data taken shows. Ill try it without the polyfill and see what the response is then. If any of this sounds crazy, please slap me upside the head and knock some sense into me. If I did not hear it, I would not believe it either.

Last night I tested my DIY 54L DPL12 w/ 16oz of polyfill. The results were encouraging and frustrating. Parameters: Sine waves from 20-70 @ 5 Hz intervals until 40 Hz In corner of room with SPL meter @ 1 meter away Phase set to 0 Crossover set to ~90 Hz Sub Volume @ 40-50% Amp PE 250W Yamaha RX-V2300 set to -44 (Found 30 Hz started to bottom out at -40.5) Pioneer DV-440 for movie and test signals Results: dB Freq 95 20 104 25 102 30 102 35 111 40 112 50 103 60 103 70 DPL12 bottomed out at 30-35 Hz before any other frequency. A little strange since it played 20 Hz well. Played several tracks on Avia and calibrated the sub. I had to turn it down a little during the asteroid chase in Episode 2. The second sonic charge hits the 30-35 Hz range while braking asteroids and sub was bottoming out. Conclusions: Probably should have tested this in the center of the room or outside to try to match the response curves. In addition, the strange shape and size of the room (as seen in attachment) makes me think the ported might give me a better response. However, for best results, I think a second sub might do a good job of pressurizing the room. Budget does not allow for this, however. Sub volume must be set at 25-30% for audio calibration. Receiver cannot exceed -30 without affecting sub performance. This is the Avia calibrated volume for my system. However, actual listening will not exceed -35. I may attempt to move sub to a different location, but this corner has always been the best location. What do you think? Should I expect more? Why would it bottom out at 30-35 Hz?

I have a sub. In fact I made my own with some help from people on the powered subwoofer forum. I guess what you are saying is that the RB-35 can handle the mid and low ranges with clarity even if the bass frequencies are sent to them?

Yamaha recommends setting mains to small if their driver is 6" or less. However, the RB-35 has an 8" driver. Which should I use, large or small setting. Actually, I am choosing between the RF-25 and the RB-35. The price difference is enough that I am having a hard time getting justification for the RF-25. The WAF is sticking its nose in. However, if I can get good reproduction from the RB-35, I don't mind saving the cash. This is for 90% HT.

I was looking at my DPL12 that arrived today (bigger than I imagined BTW) and noticed the foam that protects the surround is loose. Is there a problem if I just add a dab of glue to the this and reattach it? The part I am talking about is the ring of foam that helps space the surround from the ground if you set it woofer facing down. I assume after mounting this could even be taken off. (Not that I intend to do this)

fire pinch- Adire said the vented will give a tuning of 20Hz. I ran calculations on this and it seems to work out pretty well. There is a small bump of about 1.4dB @ 35Hz. The optimum size is 145L tuned to 16.4Hz. That's a big box! A Sonotube may work better for this driver if ported. I guess I'll see if this makes a difference. I ordered the DPL12, 3" flared port and 300794 PE 250W amp. All I have left is to put the parts together for the 54 L box. Like I said, by building two boxes I should get a good feel for which is better (for my tastes of course). Thak you again for all your help.

Adire did not say to go with Shiva or DPL12 for the vented, they just stated the same as fire pinch that the DPL12 will go a bit lower. They recommended the Tempest, but I did not want to go that big. As I said, I will probably go with the DPL12 and PE 250W. In addition, I will make both vented and sealed boxes and check them both with Avia and some sound tracks. I would think after listening to them both, the choice should become clear. I hope...

Thank you to both of you for your responses. I calculated my Qts with the sealed.xls spreadsheet from The Subwoofer DIY Page v1.1. fire pinch- I was asking about a Vented 85L enclosure. This question came up because I got a response from Adire and they said the vented 85L design w/ a 3 flared port would be better (Tuned to around 20Hz). Here is my plan Make both and see which I like better. Making the boxes is not that hard and since I can move the amp and driver from one to the other, this should be easy. The only drawback is not being able to directly AB. However, what is the worse that could happen (I start a never-ending comparison of drivers and enclosures and end up like Ear!!!) I think the winner is the DPL12. I am worried about the lower end because my current crappy 50W distorts and bottoms out on scenes that have footsteps. Like when the Ents (sp?) are walking with the Hobbits on his shoulders in LOTR2T. I have no doubt the Shiva would work, but it would be nice to see what the lower range is all about. I am ordering today so any comments are still welcome. BTW, I figured on a PE 250W or the Adire 250W. Suggestions here?

I was considering building the 54 Liter Shiva Box and was curious if the DPL12 would be a good fit? A better question would be, which driver would be best for HT applications. The DPL12 would seem to need a larger enclosure, however, I was told if given the choice on the Rava, to take the DPL12 instead of the Shiva. From my calculations, I see the net box size needing to be 70 L(2.48 FT^3) for the DPL12, however, this box size is only 54 L (1.91 FT^3). Will the insulation bring the system Q down from 0.775 to .707? Or should I look at the 85L Vented DPL12 or Shiva design? Finally, if I build the 54 L box will I have a subwoofer equal to the Rava?

The least expensive I could find the RW-12 was $430, but the shipping was an additional $55. Not a real deal when they make it back on shipping. Besides that, it is an Unauthorized dealer. Not that I mind that, but there are only a few UD's that I trust. At any rate, the Rava seems like a good choice. I imagine anything is better than my current sub. How about it matching the RB-35? Is the RF-15 better?

Thanks for the reply Frankie. That post is what got me on this alternate sub kick. I looked up the Rava earlier and it was listed at $399 or $424 w/ DPL12. This was an attractive offer and people here and on other forums seem to like it. The only problem is not being able to test drive it. I have a Klipsch dealer within an hour and can test the RW-10, but going back to my first post, this may be a faith-based purchase. Thank you again and the Rava w/ the DPL12 is starting to take the lead.

After many hours of research, I think I have narrowed it down to the RW-10. However, I am still open to suggestions for subs. Unfortunately, my proximity to a LR is limited. Therefore, many of my choices are faith based. I am into Klipsch and have been for a while. My setup currently is: RC-25 Frazier Fronts Model #? (These are hand me downs. Changing to RB-35. Also a $400 limit on fronts) Junky Sony Rear (RS-25 coming in this month) Junky Sony 50W sub Yamaha V2300 (Formally Sony STR-DE475) As you can see, this is a large upgrade from my initial system. While it might not be Home Theater Extreme, it does have the WAF. She may not understand, but the budget has been set. I wanted an SVS 20-39 PCi, however, this price was shot down and there is no compromise on the fronts to make up the difference. I can't imagine going to RB-15 in order to get the SVS. This is for 80% HT, but treat it as 100%. Please do not say Well, for $500 you could get the XXXXXX. The budget is set and can only move for shipping. There is a sketch of the room attached. As you can see, it is a little challenging. Any suggestions are welcome, even on the fronts. Sorry about the misspelled topic header.