Im looking to build a line array for a big home theater.
My main speakers cant keep up with the 8000 watt (Peavey 4080's) sub system.
I was thinking side by side 4" Dayton RS100-4 (8 of them) with XT25/60's Vifa tweeters (8 of them also per side). In a 2 cubic foot box it should extend to -3db at 55hz but will be crossed actively to the subs over 80hz LR4.
Tweeter crossed over at 2700 to 3000hz 4th order (active crossover with separate amps). I figure the use of 8 of them will also lower distortion by a fair amount.
How would the XT25 sound? Most who slam it seem to have issues from the crossover being too low. I can go with a more expensive tweeter if I have to but I dont want to. I have 2 new XT25s already but havent heard them yet.
My main speakers cant keep up with the 8000 watt (Peavey 4080's) sub system.
I was thinking side by side 4" Dayton RS100-4 (8 of them) with XT25/60's Vifa tweeters (8 of them also per side). In a 2 cubic foot box it should extend to -3db at 55hz but will be crossed actively to the subs over 80hz LR4.
Tweeter crossed over at 2700 to 3000hz 4th order (active crossover with separate amps). I figure the use of 8 of them will also lower distortion by a fair amount.
How would the XT25 sound? Most who slam it seem to have issues from the crossover being too low. I can go with a more expensive tweeter if I have to but I dont want to. I have 2 new XT25s already but havent heard them yet.
A guy asks a question about the SQ of a tweeter and you suggest compression drivers for SPL?
The system is also for low level music where accuracy is wanted. Line arrays have been described as pinpoint imaging. It has to be musical.
I appreciate the input but not what I'm looking for. Im looking to 16 tweeters to handle the power that I have two doing now.
Its funny to read that because I have read many opinions that say line arrays are actually inaccurate designs that cause too much lobing, etc.
Also the directivity isnt great at all. For HT I would not consider a line array at all. Build a quality waveguide design and have the best of both worlds.
I just built a set of arrays with twelve 5" woofers and forty-eight 10mm dome tweeters and have a few thoughts.
The first thing is the drivers must be packed together tightly, the giant flange on the XT25 causes the tweet to be larger than the woofer. It measures out at 4.125" which would cause beaming issues. For this reason, most 2-way arrays use the smallest tweeters possible packed together. Mine are packed at about 1.45" center to center and crossed at 4,300 Hz to make about a 6 foot tall vertical line.
The 2-way arrays are very efficient, very loud beasts with a huge sound stage and overpower early reflections in my garage. I would not describe them as pin point imaging, that is not "their thing". A great design for bad acoustical spaces when SPL is required with minimal floor space available--I would gather more of a PA type speaker than one for critical listening. When doing actual work in the garage, my ears can be near the floor, sitting down or standing up and the 6 foot tall array works well for that application over point source. It is hard to critically evaluate a speaker in a metal garage with cement floors and sound reflecting off mowers, tool boxes and various things in the rafters.
In your research, read information from people that have actually built, tested and measured the things to help clear up the smog. The best thing would to actually listen to a set but they are a rare site to behold. Arrays are more of a PA speaker type device and Keele's CBT system is still in prototype it seems. They are entertaining to listen to psycho-acoustics in action though--no computer simulations for how the brain accepts, rejects or changes sound on the fly.
The first thing is the drivers must be packed together tightly, the giant flange on the XT25 causes the tweet to be larger than the woofer. It measures out at 4.125" which would cause beaming issues. For this reason, most 2-way arrays use the smallest tweeters possible packed together. Mine are packed at about 1.45" center to center and crossed at 4,300 Hz to make about a 6 foot tall vertical line.
The 2-way arrays are very efficient, very loud beasts with a huge sound stage and overpower early reflections in my garage. I would not describe them as pin point imaging, that is not "their thing". A great design for bad acoustical spaces when SPL is required with minimal floor space available--I would gather more of a PA type speaker than one for critical listening. When doing actual work in the garage, my ears can be near the floor, sitting down or standing up and the 6 foot tall array works well for that application over point source. It is hard to critically evaluate a speaker in a metal garage with cement floors and sound reflecting off mowers, tool boxes and various things in the rafters.
In your research, read information from people that have actually built, tested and measured the things to help clear up the smog. The best thing would to actually listen to a set but they are a rare site to behold. Arrays are more of a PA speaker type device and Keele's CBT system is still in prototype it seems. They are entertaining to listen to psycho-acoustics in action though--no computer simulations for how the brain accepts, rejects or changes sound on the fly.
8 bilion watts, now that has to be loud -> or not.
Prior investing into this,
maybe you could post how many dBL does that sub manages.
Most probably you do not need 16 alien ant farm sized tweeters and 16 trucks of midbass units.
Besides, the more sources you have the most likely it is hard to make them work well along.
Allso do make sure to post the filter slope and corner freq. for that sub.
Along with an unfiltered response graph.
probably afterwards some handy advice could be given.
8000 watt does not describe how loud is should be.
Prior investing into this,
maybe you could post how many dBL does that sub manages.
Most probably you do not need 16 alien ant farm sized tweeters and 16 trucks of midbass units.
Besides, the more sources you have the most likely it is hard to make them work well along.
Allso do make sure to post the filter slope and corner freq. for that sub.
Along with an unfiltered response graph.
probably afterwards some handy advice could be given.
8000 watt does not describe how loud is should be.
Its kind of irrelevant how it measures. The fact is, the limit was the burning tweeter I had. I just need more power handling on the mains.
Thanks to all who posted.
I appreciate the logistical warnings as to line array theory but Im not asking those questions here. I wish I could edit the first post to delete everything and replace it with this one question:
HOW WOULD A VIFA XT25 SOUND CROSSED OVER AT 2700-3000HZ with an active crossover using 24 to 48db/octave?
I appreciate the logistical warnings as to line array theory but Im not asking those questions here. I wish I could edit the first post to delete everything and replace it with this one question:
HOW WOULD A VIFA XT25 SOUND CROSSED OVER AT 2700-3000HZ with an active crossover using 24 to 48db/octave?
Interesting points.
People have used 5" woofers with 6" tall ribbon tweeters in their arrays so I didnt think the 4.125 tweeter would be an issue.
I guess a 94mm faceplate would make a better choice like a Morel MDT30S but the cost is double on the tweeter side and I dont think it has the top end of a ring radiator. Im willing to go more money. I'd still like to know about the XT25. I have 4 of the RS100's and 2 of the XT25s already. I threw together a .28 cubic foot test box to run one of each and will see for myself if its worth pursuing. It will be measured but I need 2 for listening tests. I guess I was looking for a confirmation not to waste my time if someone factually already did a 2700 24db/oct build with them. I guess I was thinkinbg that each of 8 XT25's doing 1/8 the work would sound way better than singles crossed at 2000-2500.
Dare I say that Zaph's test of it with it not doing well under 2k for HD is likely 80% of the hate of the tweeter by people who never used it themselves. Zaph has always been right. He warns of ribbon tweeter issues and I ignored that. I built it and like it while im in the sweet spot and hate it everywhere else. He used this XT25 in what he calls a referece level system so it has to have merit. Im with him on this one and have no intention of using a 2k crossover point hence the RS100 for the midbass.
Can you post pics of what you built? It sounds awesome.
Last edited:
One interesting tidbit of info: Im at 6800 feet elevation and speakers dont play as loud here due to air density being 28% less. Less air to move= less sound made from shaking it.
Thus, my system eats more watts to make the same SPL at sea level. This makes you hit the thermal limit of any driver sooner with less spl.
Thus, my system eats more watts to make the same SPL at sea level. This makes you hit the thermal limit of any driver sooner with less spl.
That somewhat defies my logic. Correct me if I'm wrong but isn't SPL the deviation from ambient air pressure, and elevation would not matter in the sensitivity of a speaker.
well mesurements would still help-
one way to get it louder is having more power, the other one is to have a more efficient driver.
Given what SPL you need, and given the sensitivity of the tweeter will yield how many "whats" it demands. (sorthsof.)
Crossing freqvency of a tweeter indeed influences how many of those "whats" it can handle safely.
It is not irrelevant. But if You must, grab 4 of the tweeters your mains hand originaly, and connect them series-paralell, and you can use the combined tweeter with the original crossover and other "stuff" (more or less, some error will be present but thats not to worry you)
What you get is higher power handling. Just what You need.
Look at it this way, the most efficient speaker playing in space makes no sound because there is no medium to conduct the sound waves to vibrate your ear drum. Sound is the vibration of air. As you climb in altitude there is less and less air until you are in space and there is thus no sound. Sterophile mag is based in Santa Fe NM and they are at altitude with a 18% loss in SPL. Its explained there, wikipedia, and in several papers. Read the ones you will credit but all say that SPL is inversly proportional to altitude. I lived in NY and you cant hit 131db in the car in colorado like you do at sea level. When my home subs that I came here with could only hit 100db at its full output with a 1000watt amp and a 15inch woofer, I knew I had issues. In your definition of ambient air pressure being used, the dynamic range is whats affected. The piston of the speaker cone moving air is less efficient as you climb higher so yes it varies pressure but by a lesser amount.
The exact same thing is what happens in a car's engine. It has less air to compress so cylinder pressures drop. My corvette makes 822rwhp at sea level and has a 28% correction factor at 6800 feet making about 600rwhp here in colorado. The psiton moves from the bottom of the cylinder upward but has less air to compress thus making less peak cylinder pressure. My cranking compression at sea level is 205 and its 155 here.
I could quote various web sources on the topic but simply search for 'sound pressure vs altitude' and find the sites you will credit. I dont want to start posting sites and having them be the topic of debate here rather than the input on the XT25 tweeter.
Last edited:
You'd be surprised at what CD and horn/wg can do
And for sure better directivity.
Actually Im willing to look at it but what I gain in horn efficiency, I lose in power handling from a lower crossover point.
Has anyone crossed the XT 25 over at 2700-3000? How does it sound?
Hi,
Burning tweeters are very seldom due to a speaker being too small.
Amplifier clipping or a poor crossover are usual causes of burnout.
No good reason to have more than one tweeter in most cases.
The XT25 should be fine c/o actively anywhere above 2KHz.
Note that simple active crossovers are disaster when it comes
to speaker building c/o's, the result is nearly always wrong.
The MMTMM design here should be interesting :
Zaph|Audio - ZA5 Speaker Designs with ZA14W08 woofer and Vifa DQ25SC16-04 tweeter
Shouldn't be too difficult to substitute the XT25 tweeter.
rgds, sreten.
Last edited:
I've had them crossed at 2500 lr2e and they weren't bad at all. I've recently switched to B&G Neo3 pdrs in my mains, but I have plans to implement the XT25s into my surround speakers as I was always quite pleased with them.
that altitude and SPL level thingy keeps me bugging.
for some reason i was allways thinking that less densid air is not as hard to move than densid.
given equal power, i would had been thinking it would yield same SPL.
then again a bit reading shown that altitude has its effects.
on the otherhand, i did find a comparism meurement.
difference between sealevel and ca 2150m got the results of:
no mre than a decibel difference.
now thats intresting, isin't it ?
for some reason i was allways thinking that less densid air is not as hard to move than densid.
given equal power, i would had been thinking it would yield same SPL.
then again a bit reading shown that altitude has its effects.
on the otherhand, i did find a comparism meurement.
difference between sealevel and ca 2150m got the results of:
no mre than a decibel difference.
now thats intresting, isin't it ?
Does the Neo3 have top octave air? I was worried it would sound closed in up top. I love the idea of using tweeters that have the diaphram really close like that.
The tweeter is a 5" ribbon and it stretched and was in contact with the felt behind the foil. It literally smoked up and burned the felt. The amp isnt clipping.
The crossover opinion is one I dont share because the slopes I would use actively would be rediculous to build as a passive.
Thanks for the input on the tweeter and the Zaph project. I like the idea of multiple drivers for the dynamics you can get with each driver handling a small portion of the signal. I really wish I could hear a well executed line array to have first hand knowledge on the approach. Anyone near Denver/Colorado Springs CO?
Thanks for the excellent opinions so far.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.