Whatever happened to DCM's Steve Eberbach? - Page 37

If he's looking at the same schematic that I have it does list C4-100uF, C5-6.8uF and C7-47uF all as non polar electrolytics, but looking at your photo C5-6.8uF has to either be the large light blue one in the middle of the board (which should be a Mylar) or it's the yellow one which looks like another film cap, possible polypropylene. A 6.8uF electrolytic would be smaller.

So the only thing that I would change for sure would be C4-100uF and C7-47uF electrolytic capacitors.

So to find the answer to your question do a search for “replacing caps” in this thread. It's been covered about quite a bit here with others. While I mean no disrespect and I do enjoy helping where I can, it seems that a lot of the same question are being asked. A simple search first would save time. Post #1052 was the most recent discussion on the matter.

I hope this helps.

Hello, Mr. Hauser. I have read a bunch of posts here and you seem like a ridiculously knowledgeable person regarding DCM.
I would like just your quick opinion on placement when you have a minute.
I have a pair of TF-350s, a pair of TW-1As, and 2 pair of TF-600s. I just picked up my second pair and am reconditioning them with new grills right now. They seem to perform well. I have created a 'theater' room with a concrete floor 25 ft square. I cannot place these near the back wall as indicated in the DCM manual.
1. My main concern in if I use all four as fronts, IYO how far apart should they be at minimum to get enough out of the rear firing tweeters? 2. Should I aim them at same inward angle or should I try to create 2 hot spots with slightly different angles?
I am driving them with a reference Carver 300 series tube CD player, through a Carver c-11 preamp, into an Carver M-500t for 1 pair, and a Carver TFM-35 for the other pair.
Thanks for your input and I am glad there is still the enthusiasm out there for DCM.

Jamie - Thanks for your reply to my questions and pointing out the other posts regarding replacing caps. Admittedly, I have not read through the entire thread as it is fairly lengthy and deals with various DCM models, so in haste, I just charged to the end of the thread and posted my ??s.

It sounds like you have a very strong knowledge in speaker electronics and the DCM models. I have been reading up on capacitor designs http://www.sound.westhost.com/articles/capacitors.htm, which attempts to dispel some of the hype regarding the various dielectric materials and how effective they really are in audio. A quote from the article states:

"One thing that may be very important for passive crossover networks is the material used for the 'plates' of the capacitor. Metallised film caps may not be the best choice because of the resistance of the film itself. The film is usually extremely thin, and it may not have a low enough resistance to allow the full current required. I have not experienced any problems with this, but a film and foil type is more suited to high current operation than a metallised film construction. "

"Bipolar (non-polarised) caps are (IMO) simply unsuitable for use in passive crossovers, because they are so small for their capacitance that heating is far more likely ... whether because of power lost in ESR or dielectric losses. Wide tolerance also means that the network will probably not be right unless it is tweaked, and it will change with time anyway. "

Do you agree with this?
Based on your post #1052, the higher cap values of 47uf and 100uf are less critical than others and why electrolytic caps are used initially (plus their size and costs favor the manufacturing process).

So, my question is since the speakers aren't "broken" and sound pretty darn good. I have read that the electrolytics break down overtime and there will effect the sound quality. Is there anyway to gauge or determine EOF of those caps?

Thanks for your help!

Bill K.

Hey Bill. I'm not sure if your EOF abbreviation was a typo and you were referring to EOL (End-Of-Life). If so, Jamie has said that the electrolytic caps are good for 10-12 years. (See post 1057 on the previous page).

I just purchased a pair of TW3's that Jamie helped me out with regarding the caps. I changed the electrolytics first and then swapped the mylar caps for polypropylene. You can start at Post 1043 on page 35 to follow along on the help that Jamie gave me. It might answer some of your questions.

Changing the electrolytic was a dramatic improvement. I changed them on one of the speakers and then plugged it in and compared it to the other speaker with the original caps. The original speaker sounded like it had a wet blanket over it compared to the one with the new electrolytics.

After I got the electrolytics changed on both speakers I swapped out the mylar ones. I did the same thing where I swapped them in one speaker and then compared it to the other. I feel I could hear a difference, but it could just be that I knew they were changed in one of the speakers. I'm not sure if someone else would be able to hear the difference if they weren't specifically trying to listen to them to hear the differences between them. I feel that it did make a difference although it was very subtle.

I also have a pair of 1000's that I purchased in 1989. They still sound great even though I have never done anything to them. But after my experience with changing the caps on the TW3's I am definitely going back and replacing the electrolytics in the 1000's. I am not going to mess with the mylar ones in them.

Unfortunately ERSE currently does not have the 47uf or 100uf cap in stock. But you can use a 22uf and 25uf wired in parallel to replace the 47uf. See the picture on post 1063 on page 36 where I did that on the TW3's where the blue caps are stacked on top of each other. Likewise you can combine other lower value caps to make a 100uf.

47uf 100v NP
http://www.erseaudio.com/s.nl/it.A/id.4594/.f?sc=15&category=833 (not currently in stock)

Or combine

http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-22-0-PB
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-25-0-PB

100MFD 100V NP
http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-100-0-PB

or combine four of these

http://www.erseaudio.com/Products/NonPolarElectrolyticAll/ANP10A-05-25-0-PB (unfortunately they don't have higher uf value caps in 3% DF in stock that can be combined).

I had sent Erse an email yesterday about when they will have the 47uf and 100uf caps in stock. I need some for my TW7's and the 1000's. I got a response today telling me it would be 2-3 months before they are back in stock.

I hope this helps. I'm just relaying info that I got from Jamie. I'm sure if he wants to add to this he will. I'm just trying to lighten his load a bit - he's helped me out a lot!
Edited by TonyTW3 - 3/1/13 at 9:13am

Hi Tony -
Thank you for your informative reply and yes you are correct that I meant End Of Life (not End Of File ) Based on your upgrade experience, I'm convinced to go ahead with the cap upgrade. I have been thinking that I will need to go with multiple caps in parallel to achieve the 47uf and 100uf values. I hope that this approach will also help out with the packaging of the caps on the existing PCB due to the enormous size of the polypropylene caps (which is why I was considering going with external crossovers).

I'm also looking into building out the stands of the TF1000 to create a larger platform and adding some weight and then add some sorbothane feet for better stability and isolation. My TF1000s are sitting on tile flooring and are pretty stable, yet I think this will help with tightening up the low end.

So it looks between upgrades to the speaker crossovers, bases and installing another new toy (Marantz NA7004 Music Server), I'll be busy for a number of weekends.

Good luck on your TW3 upgrades!

Thanks again.

Bill K. / So Cal.

I had the chance to sit down with Steve for awhile yesterday and I ask him what his thoughts would be on your questions. I'm assuming you are planning on a 7.1 channel system using the 2nd pair of TF-600 as "width channel" speakers.

Steve suggested that the front channel speakers should be 8'-12' apart and 2'-3' off the back wall, both looking straight ahead. The width channels should be moved forward and also 2'-3' off the side walls but need to have a toe-in so that the sweet spot (see insert in the middle of the diagram) points towards the listening area. You could use the TimeWindows as side surrounds, again with the same distance of the side wall but have the apexes looking at each other. The Tf-350's could be used a back surrounds in you like. He also suggested that you could put the TimeWindows in the back and to set the crossover for the TF-600 for 40-50 Hz.


You did not mention a center channel speaker. Also, if you were planning on using two of the TF-600's on just one channel, Steve said he would not recommend that.

First, I have no formal training in electronics. My opinions would be based on what I have read (the link you provided was one of the first that I had read trying to educate myself), what I've learned through my conversations with Steve, and hopefully some common sense.

While I do agree with the article (I don't have the knowledge to disagree), I do disagree with the statement
"Bipolar (non-polarised) caps are (IMO) simply unsuitable for use in passive crossovers".

Obviously, Steve's designs prove otherwise. We did talk about this yesterday. In a perfect world where there is no consideration for cost or space constraints, by all means I would use a Solen polypropylene (a $60.00 cap that's 2-5/8" x 4-3/8") over ERSE BP electrolytic (a $2.65 cap that's 7/8" x 1-3/4"). I would like to see what the gentleman that made that statement use when you need a bipolar cap with large values.

I believe Tony answered the rest of you question very well.

Good luck with your speakers.

WOW, Sir. Thank you very much for the time and detail. It is very much appreciated.

I am using a KX-Center. I have built the room wired for 7.1, however I am using a Carver CT-17 as the pre-pre-amp for 'video audio', and as such it only supports 5.1 which is ok with me for now.

This is all part of an 11 amplifier system I have put together over the last 20 years, totaling almost 5500 watts. All of the front 8 are Carvers, supported by the second pre-amp, a C-11. The center and rears are Marantz mono-blocks. I have four dedicated bass (crossed over) amplifiers, so if placement at the back wall is for low frequency response, that's not entirely necessary. If its for tweeter reflection, then I may have to rethink some things.

I will be dedicating 2 (250x2) amplifiers for the 600s. So when you mention "if you were planning on using two of the TF-600's on just one channel, Steve said he would not recommend that." do you mean one amplifier channel(which is definitely not a problem), or one stereo channel (which would definitely be a problem)?

I am more concerned with 'pure stereo' front channel and creating an audio sound stage without surround or center, (simulated or otherwise)
Do you think there would be much difference in set-up?

When you mention 'width channel' I assume we are still talking about the main stereo front channel, right and left.

Thanks again for your attention. I can't tell you how surprised I was to see this. I am super impressed by your attention to detail in building that center channel. I have scanned a few of your posts.

Btw, I live in the Grand Rapids area. If you or Mr. Eberbach are ever in West Michigan, look me up.

No, I was referring to channels different than left front and right front. I was talking width (left width and right width). You would have to have a Pre/Pro or AVR capable of providing the extra channels. Here's a couple of links to explain.

http://www.hometheater.com/content/extended-surround-sound-boldly-go-beyond-51

http://www.audyssey.com/audio-technology/audyssey-dsx-2

What Steve would not recommend taking the left front channel and feeding it to the both TF-600's on the left side of the room and doing the same with the right. Even if you split the signal and send it to separate amps for each speaker.

I made sure to clarify this with Steve because I had the feeling this may be what you were planning on.

I personally don't find a need for width channels in my system. The TW7's already provide a wide sound stage, but better yet. they can image well between front TW7's and side surround TW7's speakers. In other words, if your familiar with phantom center image that your stereo speakers provide, imagine that same phantom image between say right front and right surround.

I guess what I'm missing is are you only setting up the room for 2 channel audio? When you mention theater room, I assumed you were looking at a 7.1 system.

Shoot. Thanks for clarifying.
This is very important to me and its obvious you and Mr. Eberbach are the only ones on this planet that can lead me in the right direction.

I have the room set up for Dolby surround for video, but I am a 'purist' when it comes to stereo audio as cd or vinyl audio tracks are usually not encoded with Dolby. I have dedicated by best equipment to front right and left channel audio.
I have other speakers in the room that I engage when watching video, as I don't like to stress my better components with the distortion and transient peaks that are inherent with movies and such. I watch movies pretty loudly. :-)

I love the sound that the 600s produce, I was just hoping to increase it. I happened on the second pair rather inexpensively and it be an easy way to do so.

I would assume by placing the two next to each other I would run the risk of phase cancellation or nodal points from the rear tweeters? As this will be an integral part of my sound room for the next decade, I am willing to slightly modify the 600s to eliminate this possibility (ie. disconnect or cover a rear tweeter, possibly the ones that face each other.??)

As stated, I run a Carver Reference tube cd player directly into the second pre-amp, a C-11 Carver. I like a short signal path for sound quality, but I do use the Sonic Holography generator, which I think augments the DCM design perfectly as they are rt and left specific.

No hurry, sir. I have the system apart right now for cleaning and bulb replacements.

I think a thousand watts peak into four TF-600s would sound very nice, if I could make them work without phase problems.

Jamie can you please take a look at this wiring diagram I got from Penny Hole at DCM?



The red marking are how my crossover was wired. You can see in the following picture that mine was wired differently.



This picture was taken before I ever removed any wires from my crossovers and both of the speakers are wired in the same manner. I am wondering if it could be possible that the previous owner took them apart and miswired them.

After I changed all the caps I wired them as they were when I got them (I did not have Penny's wiring diagram). So they are currently wired as shown in the wiring diagram in red ink.

From the looks of Penny's wiring diagram:

1. My red and green wires should be swapped.

2. My brown and orange wires should be swapped.

Keep in mind that I do have what appears to be a different crossover setup (see our discussion starting on Post 1059 on the previous page).

The speakers to me still sound flat compared to both the TW7's and the 1000's I have. Not much detail in the high frequencies. Maybe that is why the cal pots were all set wide open in both of the speakers - they were miswired and someone tried to "fix" it with the cal pots.

TW-7 Clones?? You are an animal. :-))

Zoomin............Jamie is way passed animal. He's a Jedi knight and his teacher is The Force - Steve E!

You guys are funny. LOL

There's no practical way to try and modify them with any amount of success. I would use the extra set a TF-600 as side channel speakers.

Yours are wired correctly. If you look at the drawing that was sent you and numbered the terminals on the left side starting with the top one (blue) as #1 and work your way down to #6, then the calibration pots connect as follows:

Cal #1 (yellow/red) to terminals #2 and #3
Cal #2 (blue/green) to terminals #1 and #4
Cal #3 (brown/orange) to terminals #5 and #6

It doesn't matter if the wire colors are swapped from each of the cal pots as long as they go to the same to 2 terminals. In other words the brown wire could go to terminal #5 or #6 and the orange to terminal #5 or #6 as shown in the drawing. The wires for cal #1 on my set are swapped different on the right and left speaker.

The modification on your crossover doesn't matter in this case. If all the cal pots are in the max resistance position, I would think someone mess with them. I would put them in the middle position. For that matter the 3 pots at the top of the speaker should also be in the middle setting and only tweaked if you feel the need.
Edited by Jamie Hauser - 3/4/13 at 10:45am

Hmmmmm....If I could place them anywhere in the room, two rights and two lefts pure stereo, where would you put them?

I am looking into four fresh caps per your link, but Erse charges a ton for shipping if under $20. Yikes.

Thanks Jamie.

Awe crap! I need some too. There isn't enough room in my TW-1a's to go stacking smaller values either as the two 47uF caps in each crossover are already stacked on top of one another. I could get away with stacking smaller values in my TF-500's (or use a non-blue Ersa electrolytic), but I'll probably hold out.

By the time I get my TW-1a and TF-500 speakers refurbed it'll be time to start on my TF-700 and TW-3 speakers.
Edited by Doctor Morbius - 3/5/13 at 12:16am

Jamie, I'm curious to know what Steve Eberbach thinks about high dollar speaker cables, interconnect cables and even boutique power cords by companies such as Kimber Kable, AudioQuest, Analysis Plus, Cardas and others. Have you ever discussed this with him?

I sent a follow up email to ERSE after I made my post on this. They confirmed that if you place an order now then the caps will be shipped out to you "the same day we get them".

Jamie, thanks for confirming the correct wiring on the TW3's. Yesterday I took them apart and messed around with the cal pots. All of them on both speakers were set all the way counter-clockwise (to their lowest resistance values).

I carefully measured each one with an ohm meter as I adjusted them to the middle of their variable resistance value.

Just as I was getting them fired up with some music my buddy walked in. He took one look at me and said, "You fixed them!".

I am curious how you would say that your TW3's sound as compared to the TW7's. Particularly in the higher frequencies.

I spent a good amount of time comparing my TF1000's, TW3's and TW7's last night. Of the three of them the 1000's certainly are the most lacking in the lower end. I've only ever ran a 2 channel stereo through them and have often thought that pairing them with a good sub would really help them out. In my mind they do a better job than the TW3's in bringing the higher frequencies to life.

The TW3's have a much better low end and much deeper, and richer, sound stage. To me, the 1000's have more of an in-your-face sound which can be a lot of fun. The TW3's give me more of a sense of wanting to get into the music and really listen to how the interplay of the instruments is put together.

The TW7's are simply in a league of their own. The seem to combine everything I love the most about the TW3's and 1000's into one incredible sound. I have an extremely hard time prying myself away from them.

A buddy of mine was listening with me last night as we compared the different speakers. We both had a gut sense that if the 1000's were paired with a good sub that resulted in the low end getting tighter and deeper then that combo would more closely match the tonal qualities of the 7's than the 3's do with regard to how the highs and lows sound together. However, in my opinion, the 1000's with the sub would still not create the depth of sound stage that the 3's and 7's do.
Edited by TonyTW3 - 3/5/13 at 5:46am

Thank you. While that's good to know, I'll probably order the generic ones through Parts Express as I am placing an order through them for some other stuff anyway, plus I would like to get these two DCM projects finished up before the blue Ersas will be in stock.

I just got caught up on this thread. i would not recomend this AT ALL. you would end up with uncontrollable phase issues unless you could situate these in an equidistant arc around you sweet spot. Outside that finite position you would still have issues with phase. Aside from phase, you would introduce twice the issues with crosstalk that you already have. Not a good setup either way. this would have little if anything to do with the rear firing tweets. the only wa I could possibly see this would be to maybe place the pairs side bi side but reverse the positioning of the two outside speakers (using the insides in the normal right and left positions, but the outsides being the left on the right side and the right on the left side ) so as to focaus the normal radiating pattern of the intended sweet spot at roughly 90 degrees to the inside cabinets. (similar but not exactly like the time windows do) This would probably create a situation where the outsides speakers would need to be level adjusted so as to be 6 db lower than the insides (again like the TW3's and 7's). This would block two of the rear firing tweets on each side.

This is just an idea based on the direction of the intended sweet spot as shown in jaime's previous diagram. But i do not think it would work well since these cabinets are set on a flat baffle (unlike the TW's) I am sure the intentiaonal diffraction control on these units would effect this greater than I can picture. This would be a question for Steve but I am sure if the idea was a good one he probably would have mentioned it before.

Sorry for the rambling and i know i just shot my own idea down. i was just trying to work my thoughts through all processes I could come up with.

Tony, I think you hit ithe nail on the head, i don't think you were just imagining an improvement. My reasoning is that when i purchasedmy Polk SDS SRS's I performed some of the crossover updates as well as some other mods (I wont get into here for the sake of time). When doing the crossovers i would also do one side at the time and listen. With this in mind I thought that I may be imagining the improvements myself somewhat. So, I brought my wife in to listen and compare. I did not tell her which speaker I had done what to. She could hear the same things I heard (thoguh she couldn't describe them in what we may call readily understandable terms). I did this when replacing electrolytics, Mylars, and when upgradieng each to metalyzed poly's, some to film and foil, and updateing resistors to the newer non inductive resistors. I did these in steps and each time she could hear it. Sometimes easily and sometimes subtelly. But she could hear it and she didn't know what she was listening for or really even care except that her husband was asking for her assistance. Since then she has been slowly coming around though.

My recomendations from my personal experiences are to use film and foil where one can afford them, secondly metalized polys, and lastly newerr electrolytics. i am not knocking anyones caps or personal choices but have heard improvements in using the caps in the order of prefernce i have listed here, which also seems to follow common thoughts throughout the industry. Budget is a BIG factor in affordable caps. i, like Jaime mentioned earlier would use $60+ caps if i could afford them, but I cant so I mix and match. I have also found that components in series with the drivers are more crucial than the ones in parrallel with the drivers.

I also recomend upgrading the resistors. i doubted their benifits before i tried it myself but they create more of an unveiling or like you are removeing that wet blanket you described. I might not say balnket but a knapkin may be appropriate. mills resistors are great and not extremely expensive. if out of budget, dayton has some that work fairly well that are a litlle less.

keep in mind that when these speaker were built component technology was not where it is today. steve placed a lot of thought and testing into these but i'm sure if he had available then what is available now he may change some component types. (though maybe not, he is way more intellignet than myself i am sure). The speakers were also designed around a budget and projected cost to be able to sell where they wanted them to sell. They had to make a profit. component cost was a lot of that., even with small items like caps, and resistors.

Mr. B.
Thanks for your input. I know I am grasping at straws here, as I am willing to try about anything to place four 600s in this room. Two sound great. And I have the clean amplifier power to accomplish it.


I cannot place them as Jamie/Steve have suggested (at the back of the front wall) since I have bass cabinets in that area ((when I get rowdy or listen to noisy movies I shut my DCMs off, I dont like sending distortion or extreme transient peaks through them when I can't single them out with my ear, as I can't hear clipping)) So what I am trying to say is if the initial reflection from the rear firing tweeters is based on that front-wall distance, the reflection is delayed slightly more than the design allows anyway. Also, I am a stickler with distances. I measure side and back wall distances and speaker angle at least once a month, since I venture behind my system from time to time for tweaking, and sometimes I bump a speaker.

Can you explain how I might have phase problems if they are all placed on the same relative plane?.This might make it easier for me to understand how either to eliminate it or talk myself out of the situation. :-)).

I do have the availability of the Sonic Holography circuit in Carver's C-11 preamp, (one of his cleanest solid state designs) which further enhances the stereo image and creates 'soundfield depth'. It is the ONLY enhancement I ever use in the signal path. I believe this augments the current TF600 setup well, since they are obviously designed with stereo imaging in mind.

I have also a pair of TW1a's and a pair of TF-350's, but they cannot hold their own in this room, since the amount of power required would overwhelm them. My wife likes the TW's in the master bedroom better, anyway.

The main reason I won't let this go at this point is if I can create more 'headroom' in this system, for transient peaks and such, the easier it will be on the equipment in the long run. And I love headroom. At higher volumes you can still hear every piece of the music. Every piece.

Thanks again for your input. And happy listening.

Zoomin,

The phase issues i mentioned would be due to the speakers being placed at different (even ever so slightly) from your ears. if in the same plane it means that the ouside speakers are slightly farther from your ears than the inside ones this will allow the same information to arrive at your ears at 2 different times which menas that the signal arriveing at your ears at any given time is slightly out of phase with itself. This is heard as distortion and or cancelling or boosting of certain sounds. that is why I mentioned placeing them in an equidistant arc around the listening position. This would be the only way to control this phase shift without using an electronic delay. Think of yout HT system and the channel delays it uses. This is the same principal.

Another idea i had for you is the possibility of placeing them both in front but exactly back to back agin with sides reversed. this could possibly create a bipolar type setup similar to what other brands use with a single cabinet. It still introduces anomolies with phase, diffraction, etc that would be hard to account for without proper testing equipemnt. This would be another one Steve would be much better at giving a definitive answer to and why or why it wouldn't work.

TW's are excellent for HT I have both the TW and the TW3 I don't use them in my HT currently because of positioning and space issues. I am currently running my HT with TFV-8.0's as fronts, CX27's as rears with a CX17 center. I also have used my TF600's and my TF1000's as fronts but again currently do not have the spaceing for either of those. however I believe I prefer the TFV's for the HT as they seem to have a stronger bottom end however for 2ch they are not as detailed and clean sounding.

I agree headroom is great and I find myself looking for ways to increas the dynamics aas well as headroom in my HT a lot of the time. the crossover mods mentioned in this thread will help give you the impression of more dynamics by opening up more of what these speakers are actually capable of. the best i can say for headroom is use the cleanest most powerful amps you can. A speaker can handle a lot more clean wattas than are rated at most of the time (though not necessarily for long periods) vs haveing fewer watts with clipping. headroom is all about short term reserves anyway. be sure everything in your chain is very clean with as little distortion as possible and the speaker will handle a lot of power especially as transients.

To this point the TF350's would do fine as rears, centers, etc. No matter what you will be using a sub/s for HT as these maodels are not capable of handleing or producing the low frequency infromation rrequired for HT With this in mind a high pass on the other speakers could be used with very little loss of information being noticeable for HT use. This will allow the mid/bass drivers in the TF's to handle more power (headroom). the weak link would be the tweets as these are not the strongest tweets in the world. But agin some crossover upgrades to very high quality components in the tweeter circuit will reduce the crossover induced distortion in that circuit and make them able to handle more of the power you have. Again just be sure it is as clean as possible. not to knock your gear i also have a good bit of carver gear and like its warm sound. however that warm sound comes from some high end rolloff and distortion the carvers have. Though they are clean they are not as clean as a lot of other gear and most of the amps have less damping than others as well. I limit my carver gear to my bedroom 2ch rig. with no HT use at all.

Ok, I think I'm getting this.
For my 'pure stereo' rig I am using a Carver reference 300 series tube cd player, straight into the C-11, then have available a TFM-35 (250x2) and an M-500t (250X2) for the DCM600s. I use older Straight Wire Laser Link and Rhapsody interconnects with deoxit on all connections. My speaker wire is a twisted pair.
I use a Monster 3500 line conditioner. The rest of the system consists of 6 other Carvers, four of which are dedicated bass amps, used when I choose to get rowdy. As such I have dedicated 2 20 amp breakers in my electric box for the theater circuit.
I do understand some of the limitations of the Carvers, most of which occur at the limits of their performance envelop. I try to circumvent these limitations by.....extra headroom ;-). More power, less gain.
I also understand this equipment isn't the most exotic. I have a pittance into it compared to the performance, which wide open with all 11 (8 Carver, 3 Marantz) amplifiers pushes almost 5500 watts peak. I have purchased almost none of it new, preferring to spend just a little each year in upgrades.

If I place all four in front for now, iyo would I be sacrificing stereo imaging or dead sound areas (nodal points) in my room?

Thanks for the explanation. I might not be the purist I have thought. Some of these guys are really fanatical.

Zoomin,

IMO I would not do what you are suggesting.

You definately would scarifice some of the imaging , soundstage, and also clarity due to the phase shift and crosstalk issues that you will be adding. It seems like you are pretty much committed to do this at this point and are try9ng to justify it. let me say strongly; this equipment and system is yours and the only person you must please with it is yourself. try and see how you like it. If you like it great, if you dont remove a pair or try one of the other situations I mentioned before or any other that you may come up with for that matter. See what you like and use that.

Good luck and let us know what you come up with.

I in no way wanted to sound like I was taliking down on your Carver gear. I personnaly own the C-11, C-2, TX-11A,(2) M400A'S, M200, M1.0T, M4.0T w/ Silver Seven transfer function. I also own tons of vintage Marantz (one of my weaknesses). I use a Marantz AV9000 AND (2) MM9000'S in my HT. The older marantz and Superscope Marantz is similar to the Carver with a warmer sound (again due to roll of and distortion characteristics). They sound great , but for me are not as good for high volume listening because of their distortion characterisitics and damping factor. Carver and Marantz are great gear.

Mr. B
So let's say what I have currently set up is a 'soundstage rig' and a HT or 'rock and roll rig'. What I often find, and its sooo frustrating, is fantastic sounding systems have no balls, and very loud systems have poor sound quality.

Previously I had mentioned my two pair of 600s, with the accompanying Carvers, this is my 'soundstage rig'.

Don't cringe, but my HT 'rock and roll rig' front three pair are AT series Cerwin Vegas, two pair AT-10 and one pair AT-12. I also use 2 SW-12 cabinets I push them with a pair of M-200t s, the SW cabs with a M-400t, and a M-1.0t. I am switching the TFM-35 from the AT-12 pair to the second pair of 600s. The AT-12s will be getting a spare PM-900 I have laying around. This circuit I will actually be coming from a EV 8 channel board so friends can plug in if necessary. The tweeters are great, they have boomy bass, but the mids suck. They sound nice with enough clean power. And they will handle an absolute BEATING. I am not afraid to walk out of the room at a party.
I also have 2 EV S-181 enclosures - they aren't great for sub frequencies, but they are thunderous for rock and roll from 50 hz up to 150 or so. I dedicate 2 Carver PM-1200 s, one bridged mono to each. Those Carvers make those EV cabinets spit insulation out the ports :-) My wife found a scosche hand held decibel meter in a pawn shop for $5. Again, this was for fun, as my goal is not SPL. While there is little frame of reference here, I can currently produce over 117db at 15 feet. This is with no horns, or pro cabinets (except my 2 EV s)

My favorite setup is the M-500t with two 600s, occasionally flipping on up to four woofer cabs. But you are right, when I run it all, I get weird dead spots in the room.

What I am after is a balance of them both. A very strong, loud, accurate system with lots of dynamic headroom, without spending $100k.

I am crawling toward this setup already, as I have stated I use the louder pieces for the HT, and the more accurate pieces for pure audio listening. I simply switch between the two by flipping power switches on amplifiers.

Now. my strengths being in mechanical and not audio engineering,
1. Is there a way I can 'mike' this system in an effort to identify weak areas of the room?
2. Or is it just a given that I will have dead nodes because I have different sources (drivers) for the origination of the audio and I have to put up with them?
3. Have you seen any success with a modified arc type placement? My room is 25 x 25 feet square with a concrete floor and front wall.

I guess what I am after is a way to be subjective rather than objective in measuring the results, so I can be realistic when I post them.

Thanks again for the attention. I have hit a wall, and the next steps won't be pretty.
What I really want eventually is a pair of Silver Sevens. I've seen Bob Carver is planning on reintroducing them. I can't swing new ones, but it might bring the price down on some old ones. And if you ever want out of that 4.0t, I am your man. )))