which diy speaker?

[powens]

I am wanting to begin construction on a pair of speakers soon. I started a thread a couple of weeks ago about GR-Research speakers, but the general consensus seemed to be that there were better options out there.

I currently have Ascend speakers and would like to build something that will outperform these speakers. Right now I am looking at both cjd's RS150 mtm and the Modula MT. I am focusing on these speaker options due to a small budget after all the tools have been purchased. I know both speakers are excellent, but I am really just interested in hearing opinions on which speaker yall would build if you were doing it and why?

Also, both speakers have the option to use either the RS28a or 27TDFC for the tweeter. I greatly prefer a nuetral sound as compared to bright. In addition I have a live room with wood floors. So I was wondering which tweeter would provide a more nuetral sound.

Thanks for your time.

[cotdt]

i think this will be the 5th RS28A versus Seas 27TDFC/27TDCFG debate on this forum. Anyway, answer is RS28A. Cheers!

[Hdale85]

I believe there are more that prefer the rs28-a and im guessing the 2 MT's sound very simaler while the Modula uses a bigger mid so it'll have more low end bass extension and what not. Thats what i would guess of course i havnt listend to them I can tell you that I'm building the TMWW 3 ways and I've chosen the Modula MT's for my surrounds, Unless someone wants to create a 3 way bookshelf speaker which im concidering getting some help for creating one.

[WillyD]

Actually, from what I have gathered, the RS28a will provide a more "neutral" sound. Everyone says that it does sound like the aluminum tweeters they had grown to hate but that it sounds quite good.

Edit: If you want to really outperform the Ascends, then build the Modual MT. You will not be dissapointed with them. :twisted:

[Jim Holtz]

i think this will be the 5th RS28A versus Seas 27TDFC/27TDCFG debate on this forum. Anyway, answer is RS28A. Cheers!

I've built Modula M/T's with the 27TDFC, Natalie P's with RS28 and Dennis Murphy's Rs 3-way with the 27 TBFC/G so I have them all in house and have spent a lot of time listening to each. All are very nice tweeters but my favorite is the 27 TBFC/G. It has the full bodied sound of the RS28 but has the top end air of the TDFC. The RS28 is a little dead on top to my ears. YMMV... Neutral is in the ear of the beholder.

Jim

[cjd]

IMHO, there are two key differences to consider when choosing the Modula MT vs my MTM - what (if anything) you're crossing to and where for low bass duty, and what kind of output you want.

The Modula MT will have a bit fuller bass and can handle being pushed harder, BUT it also starts out about 7dB lower per watt input.

So.

If you're crossing 80Hz to a sub and want loud, I think the MTM will better supply this.

If you don't need loud, you're on your own. I haven't compared these two directly. Jim has though.

You mention budget - my pick would be the TDFC. They're all exceptional tweeters and it really is personal pick. TBFC is last on my list personally, but that's because it doesn't get along with my ears quite as well. But between the cost of the tweeter and crossover, the RS28A bumps up cost a handy bit for a pair.

C

[powens]

I plan on trying to crossover to a sub at around 60 hz. So as far as bass output as long as either can handle that I will be satisfied.

As far as tweeters go, I saw a post with JonMarsh mentioning that the 25xt and RS28a are basically drop in replacements for each other. What do yall think about using the 25XT tweeter instead with these designs. I know that most people thgink this tweeter is not as good as the RS28a, but I have heard this tweeter and found it to be quite pleasing to my ear. In addition, I could always swap it out with the RS28a if I was happy with the performance or to compare performance.

[cjd]

Don't bother with the XT25 IMHO. It's granier in the lower frequencies where these designs push without specific attention, and I'm not sure the attention is there (mine certainly doesn't have it )

60Hz is workable, though perhaps not quite as ideal. Will require you to go ported with either (I was thinking sealed before) which means a stock receiver crossover may not do this quite as well...

C

[powens]

CJD,

What do you mean by the reciever's crossover not quite being ideal for 60 hz? I definitely had planned on going ported so that is not a problem. Do you think the mtms could handle a 60 hz crossover?

Also, I will be driving these speakers with a HK 635. Do you think the reciever can handle the mtms or would I need to get an additional amp for them?

[cjd]

The issue is that many receivers default behavior is to roll off your "small" mains 2nd order, and toss a 4th order on the sub, assuming additional 2nd order slope from a sealed box.

I think 60Hz is reasonable 4th order, though pushing the RS150 a little bit if you crank it. It's really best suited to 80Hz (or even 100Hz). The RS180 is better suited at 60Hz ported, though not by much. I'm not sure you gain much total SPL either way though, since the MT sensitivity starts out so much lower.

60Hz really screams for something bigger.

Just my thoughts.

Again, I do not think you would find yourself disappointed either way. I'm being picky and suggesting on the conservative side of things. I've cranked ~95dB out of mine running full range with some VERY bass heavy stuff and no troubles - even crossing 60Hz will probably get you another 10Hz of range, though I really should go run the numbers to know for sure.

C

[powens]

CJD,

I'm new at this so forgive me if I am way off base. Could I adjust LT2 in the crossover of your mtm to a stlightly higher inductance in order to slightly adjust the upper frequencies of the 27tdfc?

[cjd]

Yes - If you go to .1mH it'll roll off a bit more starting ~10k, but off-axis suffers as well. I would not go bigger than that. I tested with and without that inductor - going with it in the first place was a bit of a tough call.