Choosing a design, a little help please : )

[NEO Dan]

Hi all,
this is my first post here. I think i've come to the right place

I really like what I've seen here so far. The design work you all do here is inspiring.

I've been pondering two different designs in my head lately:
1: An WMTMW 2.5way RS180-4 & 27TBFC/G
2: A system with a MTM using a pair of Dayton RS52AN-8 as the mids and possibly a ribbon for the tweeter like the Statements. I'm thinking of going to 4-8" or 10" for the bass array portion. This would be of modular construction.

The goal is to build something that's 2.83v sensitivy is as high as possible. I don't mind going to 4ohm nominal impedance to get it.


Hi again, and thanks for looking this over
Dan

[servicetech]

The goal is to build something that's 2.83v sensitivy is as high as possible. I don't mind going to 4ohm nominal impedance to get it.

Have you considered using pro Drivers?

[---k---]

Are you looking for a completed project you can build, or are you looking to design one from scratch?

If you're looking for a completed project, not exactly what you asked for, but you should be looking at:
1) Khanspires - CJD has said he's willing to do a Seas crossover and has the data. Or, take a look at his new HT design in progress.

2) Look at the Modula Neo or Lineup R44.

If you're looking to design from scratch, this place likes to go all out when designing speakers - this means full measurements and simulations. This is a very helpful if this is your style too.

[NEO Dan]

Serivcetech,
PHL 1120 come to mind. But I'm not looking to go that extreme. I should have said I want to buld something that's big on bang for the buck, mid 90db's @ 2.83v is enough for me.

---k---,
I think i'm looking for more peak SPL capability than 2-RS180 can offer, otherwise I might have built your Khanspires, or the Modula.

The RS52 idea is bassed on it having lower HD and being more efficient than the W4-1337.

Your Khanspires are really ;x( what is the 2.83v sensitivity?

*****

Is there any specific Free software I should look into for acoustic measurement? I do have a ecm8000 and usb preamp that I use with REW for basic subwoofer tuning.



Thanks
Dan

[ThomasW]

Hi Dan and welcome... :T

It's problematic doing a modular system with a MTM section that uses domes. This is a function of the relatively highish XO point needed to protect the domes and the distance between the domes and a modular woofer/midwoofer section.

This is one reason why designs like the Statements and the Kanspires use cone mids that are able to play lower.

A customized version of the NeoDcc using a wider baffle with a ribbon tweeter would IMO be pretty sweet. It could set on top of some bass bins to increase the overall output.

[cjd]

I think i'm looking for more peak SPL capability than 2-RS180 can offer, otherwise I might have built your Khanspires, or the Modula.

Khanspires don't use the RS180... They're 90+dB sensitivity...

[rc white]

It helps if you elucidate precisely why you want the nominal efficiency to be as high as possible.

[---k---]

---k---,
I think i'm looking for more peak SPL capability than 2-RS180 can offer, otherwise I might have built your Khanspires, or the Modula.

The RS52 idea is bassed on it having lower HD and being more efficient than the W4-1337.

Your Khanspires are really ;x( what is the 2.83v sensitivity?

*****

Is there any specific Free software I should look into for acoustic measurement? I do have a ecm8000 and usb preamp that I use with REW for basic subwoofer tuning.

Thanks
Dan

As CJD pointed out, the Khan's use an RS225, not the RS180.

I think you are over estimating your SPL needs and putting to much value in to highly efficient designs. This seems to be a common thing around the net these days. People really think that a speaker needs to be able to do 115db continuous. In a real room, this is far from the case. And efficiency? They make really powerful amps for a reason. Just my opinion.

Not sure how you'll get to where you want to go with an RS52 mixed in.

Sounds like you're wanting to design from scratch. Good luck. For measurements and design software, take a look at Speaker Workshop.

[NEO Dan]

Thomas,
thanks for the welcome. The threads are so long here that i've had some issues tracking things down. So much to read.
I'd gladly skip the modular style build if it got things working correctly, form follows function is good enough for me.
If a cone driver is the way to go then I'm all for it. I was thinking it would be ok when I read 850hz in the ZDT3 writeup.
I did find the NeoDcc, I'm looking to go much bigger.

cjd,
thanks for pointing out the Khan's having the RS225's.
Would a SEAS(H1212) variant of the Khanspires pick up any more sensitivity.
I'd like to go with 4-Dayton SD270-88 for the bass section. This will give me the excursion cushion I want. I know the SD270 is not the same class as the RS series but there is no leaky VC gap around the phase plug and the cost is nearing half. 8-SD270's and 4-RS150's 2-27TBFC/G= $405.64, just $3.38 more than the current pricing for the drivers in the Khanspires.

rcwhite,
The short answer is my 89db rated speakers don't have the short term output ability i'm looking for on the amp i'm using. The speakers sound stressed durring some louder passages in movies. I really don't want a bigger amp I've got ~200 wpc at 8ohms.

****

I've read nearly the first 300 posts of the Khanspire build thread, I've got to get some sleep.

Dan

[rc white]

If you bi amp with a crossover at around 300Hz., ( most average music has equal power above and bellow this frequency), doubles the total effective power available, and can increase it up to four times for some signals.
A twin driver offset mtm module with a waveguide metal dome tweeter, (the tweeter needs a 3kHz. crossover for sufficient power handling), above 300Hz. in conjunction with a two by or twelve or 10inch module for 300Hz. down will give you a stereo pair capable of peaks of over 116db. if 2x12, (such as Peerless xls), down to 20Hz.withought strain, especially if a filter assisted alignment is used.

[---k---]

cjd,
thanks for pointing out the Khan's having the RS225's.
Would a SEAS(H1212) variant of the Khanspires pick up any more sensitivity.
I'd like to go with 4-Dayton SD270-88 for the bass section. This will give me the excursion cushion I want. I know the SD270 is not the same class as the RS series but there is no leaky VC gap around the phase plug and the cost is nearing half. 8-SD270's and 4-RS150's 2-27TBFC/G= $405.64, just $3.38 more than the current pricing for the drivers in the Khanspires.

rcwhite,
The short answer is my 89db rated speakers don't have the short term output ability i'm looking for on the amp i'm using. The speakers sound stressed durring some louder passages in movies. I really don't want a bigger amp I've got ~200 wpc at 8ohms.

Dan

I shouldn't speak for CJD, but I'm going too. :P

The RS28 is rated at 91db and the Seas 91.5db. There isn't any padding on tweeter in CJD's designs, so the sensitivity is the same as the tweeter. Likely not enough difference to notice. This is about as sensitive as you're going to get in a standard design. Only way to get higher sensitivity is with horn loaded or wave guided tweeters.

The SD-270 is the 10" Dayton DVC Sub. First, it is 10", which is 2" wider than an 8", and that would require a baffle change, which is a new crossover design. Second it is a totally different driver, which will require a complete redesign of the crossover. Third, the crossover point in the Khans (and most 3-ways) is 350hz, you're not going to want the DVC playing that high.

CJD spent a ton of time taking the measurements, designing the crossover, taking more measurements and then tweeking the crossover. I think most of the people posting these questions underestimate the work that goes into these designs, and how much work it is to redesign it for someone.

I'm not trying to talk you into the Khans for my own ego. I could care less. These things make me extremely happy, and that is all that matters to me. I just think you're misguided.

Again, I think you're over rating sensitivity. There is lots of reasons that your current speakers sound stressed, not just sensitivity. They're likey running out of xmax and have less suppressing crossovers.

If you still want 96db sensitivity, you're going to have to go horn or waveguide loaded. Nothing wrong with that. Its just there arn't any current projects here that would fit the bill.

So how big is your room and what are your current speakers?

[cjd]

Yeah, questions to be answered: what do you have now speaker-wise, how big is your room, how far away are you.

These will better identify how to solve your problem.

Don't bother with the 10" you pointed to - we talking SQ or SPL? You go on about leaks around the phase plug - you have ANY experience to suggest why? I can say I've pushed my RS270's WAY beyond their xmax (I've hit xmech, and let me tell you, it's not easy) and never a whisper of issue from the VC gap and being phase plugged.

The weak link in all of these designs is, as far as I know, the tweeter.

Going with more woofers will not do a thing to solve this. If bass output is an issue, you need to build mains that can cross 50-80Hz to a quality sub (or subs). The Khans can be built with a slightly reconfigured cabinet to sit on top of a sub (or to have a sub on either end so it's a SWMTMWS). It should start to run into power compression issues around 105dB and probably will max out around 110dB. That's one speaker @ 1M. That's with pink noise. Peaks they'll be capable of even more since power compression is less an issue with transients. I'm pulling numbers out of the air here, not absolutely sure.

I continue to use this design simply because it is convenient, not because I think it's what you need. I may be working with someone local to me on a HT system using pro drivers.

C

[ThomasW]

I did find the NeoDcc, I'm looking to go much bigger.

The addition of sealed box bass bins turn the NeoDcc into an impressive fullrange speaker. Doing this requires bi-amping...

[---k---]

Thomas,
I'm sure in a normal home environment the Modula NeoDcc has enough power. Just for my own curiosity, do you know off hand at what point the RS52 runs out of gas?

[---k---]

I may be working with someone local to me on a HT system using pro drivers.

C

I was wondering if anything ever came of that or if it was just another internet dreamer. I hope it does come about. I think there is a lot of potential in pro drivers, but most of the stuff I see around the net is just thrown together - little in the way of measurements, etc.

[Jim Holtz]

Since everyone is kicking in advice, here's mine. Your 200 watt amp has enough power to handle about 115 db with true 89 db speakers. Many if not most commercial speakers are way over rated from their actual sensitivity. If you're stuck on high sensitivity speakers, check out Legacy Focus. They're about 93 db actual rather than the rating but they will get loud. However, if you play them really loud a lot, you'll start to loose the Eton midranges they use.

I agree that the Dayton drivers you mentioned have poor sound quality and are poor choices. If you want effortless dynamics and ground shaking bass, it will require a sub or subs to accomplish it. For best sound quality, cros the sub(s) to mains that roll off around 50 Hz. and let the sub(s) handle the bass below that.

Here's a link to a post from a friend of mine that built the Statements design Curt and i developed. Click here You could do the same thing with the Kahnspires. I'm not sure where Chris came up with his figures but based on the Statements modeling, they should handle 115 db peaks with out breaking a sweat.

Good luck!

Jim

[ThomasW]

Thomas,
I'm sure in a normal home environment the Modula NeoDcc has enough power. Just for my own curiosity, do you know off hand at what point the RS52 runs out of gas?

[---k---]

I was thinking about max SPL.

[cjd]

they should handle 115 db peaks with out breaking a sweat.

Peaks, yup. Khan's will easily bump 115dB peaks too. I've done 120dB peaks on the 3-ways I've got.

I was talking continuous playback with nominal levels.

C

[Jim Holtz]

Peaks, yup. Khan's will easily bump 115dB peaks too. I've done 120dB peaks on the 3-ways I've got.

I was talking continuous playback with nominal levels.

C

Thanks Chris,

That sounds like what we came up with too. I can't believe anyone would try listening at 115 db continuous. That hearing damage in nothing flat.

Jim

[---k---]

And I can't believe that there are organized competitions to see how loud of a subwoofer you can put in a car, but there are! I learned recently it is called "BassRacing". Wow!

I don't think anyone actually does listen at 115db continuous. Very few people actually get an SPL meter out and see. I think it is just a lot of people guessing that the levels they listen. The amount of misconceptions repeated on the internet is amazing to me at times.

[NEO Dan]

Dang fellas,
Bass Racing is a bit of a stretch, just because I wanna build some 300l behemoths :lol: . My car stereo is stock non premium, and I'm OK with that.
My speakers are B&W CDM 9NT. I have a sub but I don't even have it hooked up in this system. I sit about 11' back. I get great bass from the speakers, but the dynamics are on the strained side sometimes. I have a fair amount of experience designing (Scott's dual RL-p18 in your DIY gallery is a good example) and building sub woofers. And my goal is to be on the amp limited side of driver excursion while meeting my peak SPL requirements. I want line array bass loading in the room. As for the leaky gap, yes I've personally experienced it with the N.805 and CDM CNT. It happens around box tuning, sometimes it would be very distracting.

I have serious doubts that the dual RS225 alignment in Da Khanspire would exibit lower distortion levels at 40v input VS a quad of SD-270 in 300l tuned @~32hz with 12db per octave HPF @ 40 Q.707. That particular alignment has a peak excursion of about 5.3mm @ 50hz. Not that they would ever really be pushed that hard, after being padded down to match the RS150's. Actually the more I think about the whole idea it is very lopsided, 40v drive levels would likely be pushing the tweeters to an early grave.

Basically I need to quit bothering you guys about this idea. Go Man up and learn to use some acoustical measurement software. :T


Dan

[joecarrow]

Also, do you have an SPL meter?

I received one as a gift (my wife is so awesome to understand a nerdy request like that 8) ) and I was kind of surprised to find out that I listen to music in the mid to low 60 db range, and movies are more like 75 db during loud dialog and music sequences. Big action sequences and dramatic crescendos hit a little under 90 db peak at my couch when I'm watching movies in "reference" mode, and although I've pushed it up past 95 db peaks to see what it was like, I felt like I was going to have to speak with the police if I kept it up.

If I lived in a house and not an apartment, I could see turning certain things up to 105 db peak just for fun, maybe with short transients a little higher, but I really don't feel the need to hear it as loud as a live concert. I go to rock concerts once in a while, and if I don't wear earplugs then my ears ring the next day. That's an indication that some damage has occurred, I'm sure. My hearing is already 10 db worse than "normal", so I really don't need to make it worse.

I agree with Jim Holtz regarding speakers' overblown efficiency/sensitivity ratings. Likewise, amplifier manufacturers aren't always the most trustworthy sources for true ratings of their gear.

A final thing I would like to mention- are your main speakers set to "large" mode, or do they have an active filter to prevent the lowest frequencies from being sent to them? There can be some benefit of subwoofer integration if they're set to large, but if you're hearing bad sound in loud passages, you could really take a load off them by setting them to "small" and running the subwoofer higher. If they're really running out of excursion, this will cut down on that. Like I said, in apartment life I don't have to worry about this much, but when I was first getting this set up I gave it a try.

[Brian Bunge]

I've got 4 RS270's I'll sell you for cheap pretty soon!

[NEO Dan]

Joe,
I don't have a working SPL meter ATM, thanks for the suggestion. I might look into having an old RTA calibrated to the ECM8000 mic I have. The RTA has an SPL meter function. I know I don't listen at very loud SPL sustained levels. I just want strain free sound.

Brian,
Let me know what you want when the time comes to sell.


Thanks
Dan

[cjd]

I have serious doubts that the dual RS225 alignment in Da Khanspire would exibit lower distortion levels at 40v input VS a quad of SD-270 in 300l tuned @~32hz with 12db per octave HPF @ 40 Q.707.

If they're within their excursion limits, I don't have any doubts on the matter at all. The RS225's start out so significantly far ahead distortion-wise. In the bass department, we're talking drivers that tend to out-measure the Seas W22's (but don't do as well as the W22 as frequency goes up). That said, why a quad of one but not the other? 4 RS225's would be fun. I should be able to work up a WWMTMWW if that's what you're shooting for. The data I have should work perfectly, just need to series-parallel the woofs and rework the crossover.

But yeah, at 40v input sustained the tweeters are where I'd expect to see failure.

Also, I think you're being exceedingly unfair to phase-plug drivers on the whole. I've not run the larger ones ported (only my MTM's with dual RS150's are ported - the rest I've done are all sealed) so maybe that plays a role - Jim should be able to speak to that. But never a whisper of an issue from the VC/PP gap. I tend to be sensitive to that kind of odd thing too.

On the B&W's - I'm not surprised they seem to strain, entirely. Build and materials seem targeted to a different kind of sound. Loud isn't it. More of a "smooth vocal with airy highs" sound best heard at around 80dB.

[Jim Holtz]

If they're within their excursion limits, I don't have any doubts on the matter at all. The RS225's start out so significantly far ahead distortion-wise. In the bass department, we're talking drivers that tend to out-measure the Seas W22's (but don't do as well as the W22 as frequency goes up). That said, why a quad of one but not the other? 4 RS225's would be fun. I should be able to work up a WWMTMWW if that's what you're shooting for. The data I have should work perfectly, just need to series-parallel the woofs and rework the crossover.

But yeah, at 40v input sustained the tweeters are where I'd expect to see failure.

Also, I think you're being exceedingly unfair to phase-plug drivers on the whole. I've not run the larger ones ported (only my MTM's with dual RS150's are ported - the rest I've done are all sealed) so maybe that plays a role - Jim should be able to speak to that. But never a whisper of an issue from the VC/PP gap. I tend to be sensitive to that kind of odd thing too.

On the B&W's - I'm not surprised they seem to strain, entirely. Build and materials seem targeted to a different kind of sound. Loud isn't it. More of a "smooth vocal with airy highs" sound best heard at around 80dB.

I would agree 100% with Chris. The RS225's are very, very low distortion and the DVC woofers aren't. They aren't even in the same neighborhood sound quality wise at any volume. The RS225's are seriously good drivers that are way over achievers.

I often play movies back loud. I want realistic playback. My Statements are ported with a F3 of 34 Hz and I use a 15" AV15 sub that has a similar F3 for movies. That combination will shake my good sized 2 story house enough that my 16 year old daughter has come down from her bed room on the top story to my home theater room in the basement and complained. I've never heard any strain or any phase plug noise.

The statements replaced line arrays with a 12" AV12 sub built into the base of each cabinet plus my 15" sub. I've not missed the arrays at all.

If you want a different perspective, email my friend Chris (CBS) that I posted the link to his post and ask him how the RS225's handle high volume. He has a very big room and likes very big dynamics. :T

Good luck with what ever you decide.

Jim

[NEO Dan]

Chris,
4-RS225's in 200l ported looks like they might just get the job done.

I still have my doubts about using drivers with an open gap due to the whistling or squeaking noises i've heard in the past.

I'll leave you the last word on the B&W


****
Jim ,
Is there any info(or a link to) on your former linearray?
I am always currious, especially now after seeing the Statements. IMO building proper array with common drivers is a real challenge.


****
All,
I'm considering purchasing the SoundEasy v14 software. For the money are there any other software packages that I should consider?

Anyone know how much PRAXIS really goes for?



Thanks
Dan

[ThomasW]

All,
I'm considering purchasing the SoundEasy v14 software. For the money are there any other software packages that I should consider?

Anyone know how much PRAXIS really goes for?

Basically $1000 for the software with the pod

[NEO Dan]

Thomas,
thanks for the info. I think I'm going with SoundEasy then.

****

Anyone have a recomendation on design or measurement software?



Thanks
Dan

[Jim Holtz]

Chris,

Jim ,
Is there any info(or a link to) on your former linearray?
I am always currious, especially now after seeing the Statements. IMO building proper array with common drivers is a real challenge.

Thanks
Dan

Hi Dan,

My line arrays are a custom design by Selah Audio. Here's a link to the PICTURE in his gallery. His line arrays have received exceptional reviews.

Jim

[NEO Dan]

Jim,
those look nice. So I've got to ask, what is it about the Statements that makes them a Superior speaker? I can't remember ever looking at the gallery there before, lots of exceptionally good looking stuff in there.


Dan

[Jim Holtz]

Jim,
those look nice. So I've got to ask, what is it about the Statements that makes them a Superior speaker? I can't remember ever looking at the gallery there before, lots of exceptionally good looking stuff in there.


Dan

Hi Dan,

It's the Statements midrange. The Omegarrays as they were named, use 10 Aurum Cantus 5 1/4" AC130 MII drivers and 8 Fountek JP2 ribbons with a 12" AE AV12 sub powered with a 500 watt PE amp in each cabinet. The AC130 MII's are a Kevlar/Carbon Fiber blend so they have a very stiff, light cone. They are very, very detailed and clear sounding that provides a very neutral sound quality.

The TB W4-1337SA Titanium mids we used in the Statements simply take the mid range up a notch. The detail and clarity is second to none, IMHO, plus the open back transmission line design gives more than a little of the spacious di-pole sound but with out the placement issues that di-poles frequently face.

Simply put, you have to spend really, really big money on drivers to get as good a sound as the W4-1337SA, IMHO. I expected the dynamics to suffer with the Statements in comparison to the Omegarrays but they are extremely close.

Two aspects make me smile every time I seriously listen to the Statements, the spacious mids and the level of detail. They are real sounding with top notch recordings. :T They've killed my desire to build more speakers. Curt and I have a monitor sized Statement under development but that'll be it for some time, for me. I'm infatuated with what I have. :B

Jim

[cjd]

On software:

If you have MS Excel, you can use the free tools over at the FRD consortium to dip your feet into the waters. If you want measurement and working with live data, Speaker Workshop handles the basic data-gathering fairly well and is also free. A bit of a headache (and that may be an understatement). Use the cables setup (seek out Claudio Negro's excellent write-up).

SoundEasy or LSPCad would be the next step up. Both top notch. Probably not worth stepping beyond that, unless you understand exactly why you're diving deeper.

Note, the software won't actually do any design work for you - that's up to you to understand what you're doing, what the software is doing. But it can optimize, and certainly helps a HUGE amount in getting the job done.

If you're ever in the Chicago area for some reason, give a shout to come hear (or not hear? ) these RS drivers at high excursion on the bass end. Or buy one and listen to it free-air, no network. Maybe knock together a quick'n'dirty sealed box. You can learn tons of things doing this kind of stuff anyhow.

I don't think anyone is intentionally pushing you in any one direction, just speaking out of our current project-list and mindset.

Jon has done arrays in the past, and his latest have been the NeoCD and the Isiris: a compact flexible 3-way and a large open baffle.

There are things you can't achieve by "loud" - open baffle is something entirely on its own. Jim's Statements seek this out in the midrange (upper end mostly). I have this set of dirt-cheap leftoverparts (i.e. the crossover has a nice bit of problem with it!) $10 open baffles I made ages ago, and there's still something they manage to do presentation-wise that just isn't there on a monopole (I want to say there's an intimacy and immediacy that dipole brings).

C

[Brian Walter]

They've killed my desire to build more speakers. Curt and I have a monitor sized Statement under development but that'll be it for some time, for me.
Jim

Come now Jim, you don't actually expect us to believe this now do you? Don't wimp out on us, you've got a reputation to uphold. ;x( I can understand being totally satisfied with your Statements, but why would that stop you from building more speakers?

If you keep this kind of talk up, Thomas is going to eject you from here

Brian Walter

[Jim Holtz]

Come now Jim, you don't actually expect us to believe this now do you? Don't wimp out on us, you've got a reputation to uphold. ;x( I can understand being totally satisfied with your Statements, but why would that stop you from building more speakers?

If you keep this kind of talk up, Thomas is going to eject you from here

Brian Walter

Hi Brian,

I appreciate your compliment and I know that making that comment is heresy but I'm just really happy with the speakers I now have. Assuming I go to work soon (I've been interviewing quite a bit) I'm going to focus on upgrading some of my electronics rather than building speakers for a while. I just advertised my line arrays and center finally. I'd had other things going on and just hadn't gotten around to it. If you know of anyone, please send them my way.

Jim