Looking for suggestions ...

[dpc rep]

My Dad is a long time, way back (HI FI) kind of guy. He is very intelligent and still goes to work every day at the age of 78, but the last speakers he built were 9 c.f. enclosures,ported to 35 Hz using an occilloscope, holding a single 12" Electrovoice (Knight) coaxial driver. He drove them for years with a 2 channel tube amp (that he built) that put out 16 watts per side and I have to say that while growing up, they were the best speakers that, at that time, I had ever heard.

Fast forward to present. He has a set of Advent Prodigy towers that he bought almost 20 years ago to replace the speakers that he had built due to not only space constraints, but also the fact that the drivers needed re-coning. Since I installed an IB sub in my ceiling and am planning on building a set of speakers for music and HT, he seems to have caught the bug again but times have changed. The Advents are in need of repair and we ordered a couple of cheap 8 inch drivers from PE to replace the rotted out drivers in his current speakers, but he is now thinking of building a new set of front speakers and moving the repaired Prodigy's to rear surround duty. The problem is, he has an Onkyo receiver (from me when I moved up little by little) that will not hold a 4 ohm load. I think it will push down to 6 ohms, but I am unsure. Are there any nice 8 ohm DIY designs out there that will compete with or better the Prodigys (8" 2 ways)?

There seems to be plenty of 4 ohm options, but not a lot of 8 ohm that I have found. He might buy a new receiver, but the old "finnesse it; walk softly and carry a big stick" mantra that he subscribes to might preclude this.

Any suggestions?

[kevinp.]

I'd suggest a ported version of the Modula MT's

[cjd]

I drive my RS150 MTM's with an amp that should theoretically be unstable at 4ohm - they run out of excursion before I have amp problems. And I've run my big towers (3ohm) on this same amp and *have* caused it to go thermal shutdown.

Though, I use an older rev of the crossover in the MTM's that's a little more even-keeled. However, the Series crossover variants (posted in the thread in Missions Accomplished) might be just the ticket...

C

[dpc rep]

What about the TriTrix designs? They have an 8-ohm design and seem simple (cheap) enough to build.

Would there a significant difference between the TL and the ported bass extension, or sensitivity?

If possible, I would like to get the parts ordered and the speakers built before Christmas.

[dpc rep]

Anyone? ........... Anyone? ............. Bueller?

[dpc rep]

I drive my RS150 MTM's with an amp that should theoretically be unstable at 4ohm - they run out of excursion before I have amp problems. And I've run my big towers (3ohm) on this same amp and *have* caused it to go thermal shutdown.

Though, I use an older rev of the crossover in the MTM's that's a little more even-keeled. However, the Series crossover variants (posted in the thread in Missions Accomplished) might be just the ticket...

C

Which design is the one that you are talking about? Does the Series variant that you are talking about have a higher impedance?

Sorry for the seemingly dumb questions, but past designing an enclosure, I am lost ... one day I might be able to figure out all the voodoo that you guys do on crossover design ...

[ThomasW]

Would there a significant difference between the TL and the ported bass extension, or sensitivity?

Not much difference.

Which design is the one that you are talking about? Does the Series variant that you are talking about have a higher impedance?

http://www.htguide.com/forum/showthread.php4?t=19887

[dpc rep]

Thanks, Thomas. I thought that was the thread, but I was unsure.

[Curt C]

What about the TriTrix designs? They have an 8-ohm design and seem simple (cheap) enough to build.

Would there a significant difference between the TL and the ported bass extension, or sensitivity?

If possible, I would like to get the parts ordered and the speakers built before Christmas.

The TriTrix is a 'high value' design, that is the Dayton drivers it uses are great bang for the buck drivers. The RS series drivers are a step higher in motor design. The TriTrix in vented form will probably meet or exceed the quality of the Advent's, but I suspect Chris's design using the RS drivers will sound even better.

C

[dpc rep]

Thank you for your input, Curt. I personally plan on building the Statements and variants thereof for my family room/HT, but I think something on a smaller order is what my father is looking for. I will look further into the RS MTM that has been mentioned earlier.

I like the design of a TL because it seems to call back to a design of "days gone by" (for my dad) and that might be something that my father might be interested in since he a huge proponent of "making more from less" and that seems to hearken from the days where wattage was expensive and 100 watts per channel was unheard of and drivers were "cheap". I also think that the TriTrix might very well fit the bill, since I would like to meet the performance of his Advents, but since I pulled the grills off and found out that the foam surrounds are totally rotten on the 8" drivers on his sealed Advents, I think almost any speaker design should seem to trounce the sound of what he currently has.

I will look further into the RS MTM that has been mentioned earlier, especially the tower design.

Thank you,
Brad

[dpc rep]

Look at that ... this thread has become a "hot thread" as noted by the little red envolope on the left ... impressive 8)

[Hank]

I still have my original Large Advents that I bought about 1972. Earlier this year I replaced the foam surrounds on the woofers with a kit I bought - don't remember the company name, but it could be found with a search of various DIY speaker forums. If your father wanted to re-foam his, assure him it's an easy job. Or, you could do it in secret and surprise him for Christmas :E When you build him new speakers he can have a sound system in two different rooms.

[Undefinition]

If your father wanted to re-foam his, assure him it's an easy job. Or, you could do it in secret and surprise him for Christmas :E When you build him new speakers he can have a sound system in two different rooms.

Actually, although I do love DIY, I 2nd Hank's suggestion. My dad has heard some of my DIY stuff, but I think he's most impressed with his old Cerwin Vegas that I re-foamed. :roll:

[geno742]

I'd suggest a ported version of the Modula MT's

Or Natalie P's which are GREATTTTTTTTTTT bang for the buck if you build the enclosures.

[ThomasW]

The NatP's are a real world 4 ohm load, so one must be careful using them with receivers that aren't happy driving lower impedance loads