Hey guys...we need a little rallying here... - Page 189

Theresa., I also like active xovers better. Very good amps are available inexpensively (gain clone or class d) and minisp isn't hard if you have measurement capability. And you can arbitrarily adjust driver delays and parametric eq comes as a free addition. No worries about driver impedance effects on the crossover circuit. Driver sensitivities don't need matching (you can even use a tweeter that is less sensitive than the woofer if you want). And the cost is quite competitive now -- just look at what a low dcr large air core inductor costs!

So, there's some encouragement.

Going to replace my SHO-10s with something similar to Brad H's effort.

I've been told some good stuff is coming so I'll just keep drooling over the thread!

I know little to nothing about speakers so this is quite the learning curve.

i have a idea, send me 1 of everything and ill take pictures of it all for you

Don't you want to take pictures of them all in pairs?

Your pictures look fine so far. It's not like you're selling Breitling watches.

You have no idea man! It's been non stop this year, I just don't mention it here. Maybe I act too nice at first and I'm not taken seriously. Maybe I should go back to my flat top military style hair cut and act meaner! Oh well. If I didn't know Bwaslo and you guys here, this project would have been marked 'complete' right when the waveguides were made up in fiberglass. But I'm charging onward and taking it the the next level......no photographer will stop that!

But yes, I will be getting the stuff back from him. It wasn't much anyway because I wanted to see how good his pictures were first. But he does have one of the poured one piece glossy baffles!

Yeah Erich I think your pictures are more then enough.

I agree! Erich your pics serve the purpose and they look great. Snap away and move on brother.

+3
Retrieve your stuff from the photographer and do your own thing - which will likely be easier than his hassle!

i also agree, the photos you have look fine.

lol werent you using a flash to bounce off the ceiling? i like how he wants to borrow your "lights", sounds like the guy has no idea what hes talking about (although to be frank thats 99% of photographers on craigslist who are responding to photographer wanted ads)

logos take me no time.. what exactly are you looking for?

Bill,

An additional reason for going active would seem to be making steeper XO's feasible, which would minimize power response anomalies in the XO region, make the woofer "shut up" sooner, and increase power handling/reduce distortion of the CD.

Question is, does that give an appreciable audible improvement.

Have you experimented with this?

Here is example of driver with stiff suspension that struggle when crossed below 1kHz.

Mummy_4_crossover_dist.png 744k .png file

Yes... I need small. I mean, I was considering in wall speakers!

Thanks for your review of the SAM1. I am going to get on the tour. We need more West Coast listeners!

What do you think of that Little Mayhem vs the SAM1? Size is then comparable and while of course bass extension is not comparable at all... If you think the SAM1 benefits from a subwoofer (AJ said maybe/maybe not and said they'd go into the 20s Hz by themselves), do you think a Little Mayhem pair with a sub would give them a run for their money?

I am looking for the right combination of small and affordable with the best audio quality I can muster. A SAM1 pair plus center is shy of $2,000. And yes, I totally know that they have the huge advantage of being finished by someone competent (vs me: cabinetry is something I have zero expertise in).

I haven't heard the SAM1. I trust DS-21 when he says it is very nice speaker. With that said, I would definitely suggest something like the Little Mayhems instead. The Little Mayhems will give up some extension, but that is a moot point if you are going to use subs (which you should with any speaker if possible). They will be capable of far cleaner sound at high levels and will give you much better dynamic capability. Beyond that, they will do a better job of controlling directivity than the SAM1 coax.

Of course, they will be a flatpack which you will need to assemble and paint or veneer and if that is not a viable option than something like the SAM1 wins out even though it won't win on performance. Given the likely price difference, you could probably find an auto body shop that would bondo and spray the Little Mayhems and you would still spend less than the SAM1s. I'm a terrible woodworker myself so I usually find others to pick up the slack for me on that end when I want it look nice.

Active can be great. Unfortunately most of the time people are not willing to take the necessary steps to do it right. You are obviously taking measurements (you'd be surprised the number of PMs I get asking for help with a DSP crossover and the person is either not measuring or doesn't know how to measure properly). Since you are enjoying the "journey" the MiniDSP is a great option.

The main point I make is that an active DSP crossover won't give appreciable performance gains over a good passive for speakers like a SEOS design. Unless someone just likes to tweak stuff, there isn't a financial, ease of use or performance case for going DSP over a well designed passive. DSP is best used for odd cases (some speaker designs are not reasonable to execute with passives), people who want to learn crossover design. It is not a shortcut as I'm sure you have found.

IME, this is unnecessary and much of the time is a detriment to performance. More is not always better and much of the time is simply worse. Yes, in some cases a very steep crossover would be needed and in those cases DSP is the way to go. Fortunately, with speakers like SEOS-12 or 15 and quality 12 or 15" pro woofers you are better off with relatively shallow slopes. Look at Bwaslo's design for the SEOS-12/DNA-360/Deltalite12. He uses 2nd order electrical slopes which sum to something greater than that acoustically. Take a look at the polars, they are exceptional. The polars would actually look worse with steeper slopes. I haven't asked him, but I doubt he was simply trying to save on one or two components.

More is simply not better.

One of the advantages of a simple 2-way directivity matched speaker whether they are Pi speakers or a SEOS-12 or 15 design is that the passive crossovers are not ridiculous or expensive. There is a confluence of factors that comes together to make this type of speaker both high performance and high value. About the only compromise with this type of speaker is its size. IMO, to exceed the performance of a SEOS speaker you would need to increase complexity greatly (aka Synergy clone) or use a far larger horn with uber-drivers which makes them far too large and expensive for most (likely doubling footprint and price would be at least 5-10x higher).

Well, then...can you fit SEOS12 baffles in your walls?

I can't really answer that, as I've heard the SAM1 but not the LM. MTG90 and AJ are both speaker designers who know what they're doing and back up their work with measurements. The LM will have a narrower pattern in the midrange and treble, and be a lot more efficient.

As for needing a sub, I say that yes, the SAM1 requires at least two subs far away from the mains for high-fidelity bass reproduction in most rooms. The SAM1 will get low and plenty loud for most uses, but "full range" speakers just don't cut it for me in room. Look at the listening position measurements in my review for an indication of why "full range" speakers sound so awful down low.

I seriously thought about one of MTG90's earlier designs as my new mains, the one with the Celestion woofer, though I like the Little Mayhem better. The issue for me was bass extension. I never seem to manage to blend vented mains with subs well, so I stick to closed boxes. The Little Mayhem closed would have an F3 of 140ish Hz, if the woofer is what I think it is. (I could be wrong by a little.)

Funny thing is, had I taken better measurements of my room earlier, I would've realized that the only way to get smooth response in the 100-300Hz range in this room would be to blend low-mounted woofers with the tops, and that would've put MTG's 8" 2-ways right back in contention.

Hehe, I know that feeling. I don't even try any more. I'll draw up a design, and then find a local artisan who's willing to take on a small commission. (My efforts at cabinetry are best hidden far from view.) That said, as with anything, bespoke commissions are expensive. My new cabinets (five in total - three mains, two "flanking subs"/speaker stands) are going to be quite a bit more than $2k...

I am offering the E-Wave Delite cabinets over on DIYaudio:

http://www.diyaudio.com/forums/swap-meet/170253-eds-shameless-comerce-division.html

I have, and see that the midrange develops dips in the vertical off-axis response; would steeper slopes not improve this?

I'm thinking of the the NHT Xd, which got great reviews and whose performance I believe was related to its use of 96 dB/oct XO IIRC.

It would make them narrower, but not any less deep. So the null would still be there, but maybe only across 250hz instead of 500hz or something (depends on a lot of things). Shallow slopes help with directivity hand off if there is not an ideal directivity match.

Yes, you would effectively widen the nulls in the vertical, but there would be issues in the horizontal which is more important. Of course if the CTC spacing were wider a steeper slope would help, but that is not an issue with SEOS.

There are situations where steep slopes are advantageous. I don't see it with typical SEOS applications. DSP is good for situations where large acoustic center differences exist or the designer simply likes to tweak. I simply don't like it as a shortcut for newbs to get around passive crossovers. I also generally question that it will give appreciable performance gains for most simple speakers.

I wouldn't read too much into reviews on a speaker especially like the NHT Xd. I just read the Stereophile fluff and the the measurements. The main advantage of the steep slopes is that they could use a small dome tweeter down to around 2khz which wouldn't be possible with a passive. Of course, that doesn't apply to any potential SEOS designs. Can you program the Xd's DSP?

One nice thing about the SEOS (or similar) paradigm is that it doesn't require crazy crossover work.

Fair enough.

It's also the answer I like, as I prefer to avoid the complexity, time, and expense.

Big expense; I just got a Trinnov box off of ebay, and I glad not to have to pay for licenses for 3 more channels.

Would really like to know how you like Trinnov in your setup. Shame Outlaw couldn't pull through.

You should really check out the Trinnov and Sherwood R-972 threads. Trinnov's no joke as long as you can put up with the R972's quirks.

The real deal? Sweet.

Sounds like I need to put something on my "saved searches" list on eBay now. Never occurred to me that people would list full-bore Trinnov there.

More or less:

http://www.ebay.com/itm/Trinnov-Optimizer-Loudspeaker-Room-Optimization-and-processor-/170939505848?pt=Home_Theater_in_a_Box&hash=item27ccc9dcb8&nma=true&si=TXdLMY3efX6ZghqWuJBGjA7KKm4%3D&orig_cvip=true&rt=nc&_trksid=p2047675.l2557

Before swooning at the amazing deal (for those thinking "huh?", I think the cheapest multichannel Trinnov box is $12K), I'll have more than triple that into it after upgrading the s/w to current, buying A/D/A converters, cables, licenses for 4 more channels (for a total of 12), a Trinnov mic, and get a nicer faceplate made for it.

Still about half the price of new, so I figure I can break even if I decide it's not worth that much.

This will be the most I've spent on anything other than houses and cars, so it's a psychological hurdle.

yep, that's what I did
Edited by noah katz - 11/21/12 at 2:11pm

Wow, I didn't know those were so expensive (talking about your $12k price). Having owned a Sherwood Newcastle R-865 and loving it, I've always lusted after the R-972. Wouldn't that be a better way to go? I'm assuming the dedicated unit has more resolution/capability/adjustability...?

Would what be better than what?

Anyway, the 972 has a few pre-programmed target curves, one mic position, no channel level control w/Trinnov engaged, and 8-ch.

The "real" Trinnov units have full user discretion of target curves, setup using multiple mic positions weighted as desired, up to 16 ch in my unit (which can be used for active speakers), and a dizzying array of contrlollable parameters like phase etc.

I meants, wouldn't getting an R-972 be a better way to go because it's all in one, but your post answers the question. The dedicated unit is obviously much more capable. Interesting, thanks.

See now I wish I didn't move away from the bay area cause I would have snuck over to your house for a listen.

Sounds like you need an advanced degree to operate that thing.