Rather than making a center WMTW center channel, would it be possible to use a single woofer next to the midrange and tweeter as shown in the attached pic? or would this not be a very good idea.
Also when measuring the FR should I place the speaker in the actual location it is to be used when designing an XO? (ie: on top or below TV or a simulated equivalent)
Also when measuring the FR should I place the speaker in the actual location it is to be used when designing an XO? (ie: on top or below TV or a simulated equivalent)
Attachments
If you set the woofer crossover low enough it will be just fine to use that configuration. What you need is for the woofer to be acting like a subwoofer and it will cost you more for the crossover parts because lower crossover points require larger values.
However, if you set the crossover below 120 - 130 Hz it should not be a problem. Now with the midrange going lower than before you will need to have a larger chamber of air with it if it is in a seperate enclosure.
Hezz
However, if you set the crossover below 120 - 130 Hz it should not be a problem. Now with the midrange going lower than before you will need to have a larger chamber of air with it if it is in a seperate enclosure.
Hezz
If I would have to cross that low to get good results I would be better off to just go 2 way or all out with a WMTW since I will have separate subs on the LFE channel likely up to near 100hz. I figure the best way to match everything would be for all 5 speakers to have a similar rolloff in the bass area. (my L/R fronts are sealed boxes with an Fsc of about 72 hz and a Q near .71).
(edit:BTW my HT amp isn't very flexible with crossover settings...the lowest setting is 100hz lowpass and the higpass can only be set to 100hz)
I really would prefer a 3-way to get keep the XO out of the vocal range. This of course is probably beyond my abilty to design myself and I am unlikely to find a center channel design to match my specs. So I guess I will have to go 2-way in the end. (all other channels will be 2-way anyway)
By chance, does anybody know of a good WMTW center channel project that would get me what I am looking for?
(edit:BTW my HT amp isn't very flexible with crossover settings...the lowest setting is 100hz lowpass and the higpass can only be set to 100hz)
I really would prefer a 3-way to get keep the XO out of the vocal range. This of course is probably beyond my abilty to design myself and I am unlikely to find a center channel design to match my specs. So I guess I will have to go 2-way in the end. (all other channels will be 2-way anyway)
By chance, does anybody know of a good WMTW center channel project that would get me what I am looking for?
I would except that most people say that MTM's aren't made to put on their side because they don't sound that great when you are off the vertical axis (or the horizontal axis when it's laying on it's side). So I would think I'd be better off just doing a simple 2-way with a single woofer over an MTM design.
Having used the MTM design and originally having it in a horizontal configuration and then switching to a vertical configuration. I would say that unless you have room to put a MTM in the vertical configuration it would be better to go with the standard two way.
If you watch a lot of old films and want to use only the single center channel I would built a three way. But for modern movies a two way is quite sufficient in the center. One thing though is that if you are still using Dolby surround instead of dolby digital there is still a lot of bass information in the center channel and you may want to cover it.
Unless you have test equipment you are better off to buy a kit with crossover already designed or Madisound can design a LEAP crossover for you for about 25 USD. It is well worth it as it will be a better crossover than you can get without spending a lot of time and money with different parts values.
If you are using the center channel with a TV stand you might check out the integrated TV/center channel speaker I built. It works rather well.
I personally feel that the center channel should be designed with vocal reproduction in mind and as long as you cover that well the speaker should be just fine. I also think that silk dome tweeters are better for HT unless you have really high end gear as the metal domes can amplify some of the bad sound of mass market digital playback.
A DIY speaker company name Zalytron used to have a really good WTMW center channel kit. You can search for it. Madisounds MTM VIFA center channel is quite good for the money if you run it in a vertical orientation.
Hezz
If you watch a lot of old films and want to use only the single center channel I would built a three way. But for modern movies a two way is quite sufficient in the center. One thing though is that if you are still using Dolby surround instead of dolby digital there is still a lot of bass information in the center channel and you may want to cover it.
Unless you have test equipment you are better off to buy a kit with crossover already designed or Madisound can design a LEAP crossover for you for about 25 USD. It is well worth it as it will be a better crossover than you can get without spending a lot of time and money with different parts values.
If you are using the center channel with a TV stand you might check out the integrated TV/center channel speaker I built. It works rather well.
I personally feel that the center channel should be designed with vocal reproduction in mind and as long as you cover that well the speaker should be just fine. I also think that silk dome tweeters are better for HT unless you have really high end gear as the metal domes can amplify some of the bad sound of mass market digital playback.
A DIY speaker company name Zalytron used to have a really good WTMW center channel kit. You can search for it. Madisounds MTM VIFA center channel is quite good for the money if you run it in a vertical orientation.
Hezz
Right now my DVD player is, dare I say, a Playstation 2 (my real one died) so I only have a stereo signal going to my amp and the amp converts it to the 5 speakers. When watching movies like this does the subwoofer channel get the bass from all the other channels?
When I do get a new DVD player (and I watch in 5.1 dolby digital) what channels get the bass routed to the subwoofer channel then? I'll have all the channels set as large.
My amp has only the most basic of features, its a Technics SA-DX750.
When I do get a new DVD player (and I watch in 5.1 dolby digital) what channels get the bass routed to the subwoofer channel then? I'll have all the channels set as large.
My amp has only the most basic of features, its a Technics SA-DX750.
One other thing I just thought of when looking through kits. If an MTM were designed as a 2.5 way with 1 woofer just to cover for BSC would it suffer from the same problems when put horzontally?
Also, wouldn't the BSC be different since it will essentially have one wide side if it's on top of the TV and even worse if it's below the TV?
I have too many questions as usual.
Also, wouldn't the BSC be different since it will essentially have one wide side if it's on top of the TV and even worse if it's below the TV?
I have too many questions as usual.
Merlinx76,
There are some differences in home theater stereos but most of them running in dolby digital send the entire frequency spectrum to all of the speakers when you have large selected. This means full range but is meant to be a simplification.
The subwoofer channel is derived from the others with dolby surround but with dolby digital it is a seperate channel with it's own content. Usually the dolby digital subwoofer channel is a mix from the main speakers so that if you don't have a subwoofer you still get some of the bass effects.
The biggest problem with the MTM is that it gives good wide midrange and midbass energy distribution in the horizontal plane when oriented in a vertical arrangement. When you put it sideways it does the opposite of what you want to happen. Some manufacturers of higer end speaker attempt to compensate for this with a crossover designed slightly different and placing the tweeter high between the two midbass drivers. But more often than not it is an asthetic consideration because most people don't like an asymetrical looking speaker.
Because of the physical requirements of your tv viewing room and space the first thing that you need to determine is where you are going to put the speaker and how big it can possibly be. After you know that you can decide on a design. There is no reason why you could not get very good performance from the three way that you posted at the beginning of the thread.
In my opinion next to having natural timbre sound in the vocal range the most important thing that the center channel can do is have three dimensional imaging. This means that the sound doesn't sound like it's coming from the speaker. For a small speaker this is easier to realize in a two way design.
In my opinion, the best sounding configuration for a center channel speaker would be a two way design build into a narrow pyramidal enclosure and up on a good stand. Like the upper speaker on a Wilson Watt/Puppy. This usually only works on a front projection screen arrangement because most people don't like the looks of this in front of the TV and unless the TV is high enough it won't work. Therefore other compromises have to be made.
It would not be very hard to design a crossover for your original three way with a low crossover point. You can have Madisound do it for your for 25 USD. I designed my main high end watt/puppy clones this way because I wanted the mi-bass speaker to cover all of the fundamental frequencies. I think it has a lower crossover point around 150 Hz. I think that this would work just fine for you. Also, a well made two way would work just fine. The center channel speaker is more forgiving than the others because it generally doesn't have to play full range music.
Hezz
There are some differences in home theater stereos but most of them running in dolby digital send the entire frequency spectrum to all of the speakers when you have large selected. This means full range but is meant to be a simplification.
The subwoofer channel is derived from the others with dolby surround but with dolby digital it is a seperate channel with it's own content. Usually the dolby digital subwoofer channel is a mix from the main speakers so that if you don't have a subwoofer you still get some of the bass effects.
The biggest problem with the MTM is that it gives good wide midrange and midbass energy distribution in the horizontal plane when oriented in a vertical arrangement. When you put it sideways it does the opposite of what you want to happen. Some manufacturers of higer end speaker attempt to compensate for this with a crossover designed slightly different and placing the tweeter high between the two midbass drivers. But more often than not it is an asthetic consideration because most people don't like an asymetrical looking speaker.
Because of the physical requirements of your tv viewing room and space the first thing that you need to determine is where you are going to put the speaker and how big it can possibly be. After you know that you can decide on a design. There is no reason why you could not get very good performance from the three way that you posted at the beginning of the thread.
In my opinion next to having natural timbre sound in the vocal range the most important thing that the center channel can do is have three dimensional imaging. This means that the sound doesn't sound like it's coming from the speaker. For a small speaker this is easier to realize in a two way design.
In my opinion, the best sounding configuration for a center channel speaker would be a two way design build into a narrow pyramidal enclosure and up on a good stand. Like the upper speaker on a Wilson Watt/Puppy. This usually only works on a front projection screen arrangement because most people don't like the looks of this in front of the TV and unless the TV is high enough it won't work. Therefore other compromises have to be made.
It would not be very hard to design a crossover for your original three way with a low crossover point. You can have Madisound do it for your for 25 USD. I designed my main high end watt/puppy clones this way because I wanted the mi-bass speaker to cover all of the fundamental frequencies. I think it has a lower crossover point around 150 Hz. I think that this would work just fine for you. Also, a well made two way would work just fine. The center channel speaker is more forgiving than the others because it generally doesn't have to play full range music.
Hezz
You should download Svante's xDir and play around with it. W-TM style can work fine but there will be a lobe off to the left or right. If the lobe is wide enough (read: you are crossing low enough) you may be able to play with the placement such that the main seating area is well covered. This may be significantly better than MTM-on-a-side in terms of lobing.
Because of my design constraints I need to cross relatively high, 300-400Hz range. As a result, I really had no choice but to go W-TM-W to force the lobe to center about the 0 degree axis.
Pretty much everything about a center channel is a compromise if you have to work around a screen/TV so you need to make the best of it. Fortunately there are a lot of potential workarounds.
Because of my design constraints I need to cross relatively high, 300-400Hz range. As a result, I really had no choice but to go W-TM-W to force the lobe to center about the 0 degree axis.
Pretty much everything about a center channel is a compromise if you have to work around a screen/TV so you need to make the best of it. Fortunately there are a lot of potential workarounds.
Merlinx76,
If I was using a direct view TV and I could place my components on the right or left wall then I would build a center channel like this. It is a TV stand with a two way built into it. The front baffle slopes back so the speakers are angled at the listener. The speakers are mounted as close together as possible near the top.
Because the enclosure is large for a two way and has non parallel walls it will give the best sound possible. If the enclosure is well built this design will outperform nearly every high end center channel on the market.
The enclosure is large enough in volume so that it is critically damped at about .5 which does not have the best bass response but has the highest transient response possible from the speaker and will be the best sounding for vocal timber. Also you can get very high sound quality from a modest costing speaker.
Hezz
If I was using a direct view TV and I could place my components on the right or left wall then I would build a center channel like this. It is a TV stand with a two way built into it. The front baffle slopes back so the speakers are angled at the listener. The speakers are mounted as close together as possible near the top.
Because the enclosure is large for a two way and has non parallel walls it will give the best sound possible. If the enclosure is well built this design will outperform nearly every high end center channel on the market.
The enclosure is large enough in volume so that it is critically damped at about .5 which does not have the best bass response but has the highest transient response possible from the speaker and will be the best sounding for vocal timber. Also you can get very high sound quality from a modest costing speaker.
Hezz
Attachments
Have you built a speaker like that? or do you know of any reputable existing designs by someonle else? How do you deal with the BSC or is it not such a big deal because of the pyramid shape? And one last question.... What about a 3 way done vertically in this fashion... Then could I cross the woofer higher without much problem? (I just don't see the point of going 3 way and only using the woofer for 1 octave 70-150hz and at 150hz a little 40 Watt midbass may still be strained fairly easily)
Mostly I am concerned about the upper regions of the voice being handled by the tweeter because in my main speakers I find I can sorta hear where the transition from woofer to tweeter occurs and while having the tweeter crossed that low (1700hz) makes for great clarity in the upper midrange it doesnt seem quite right with voices (especially female). I wanted to use a good small midwoofer as a midrange so I could XO at least up around 2500hz but I think a 5 1/2" would be lacking on the low end
I guess if a 7" woofer MTM is good enough for me for music, a 7" woofer in a 2-way shoud be good enough for an HT center channel.
Mostly I am concerned about the upper regions of the voice being handled by the tweeter because in my main speakers I find I can sorta hear where the transition from woofer to tweeter occurs and while having the tweeter crossed that low (1700hz) makes for great clarity in the upper midrange it doesnt seem quite right with voices (especially female). I wanted to use a good small midwoofer as a midrange so I could XO at least up around 2500hz but I think a 5 1/2" would be lacking on the low end
I guess if a 7" woofer MTM is good enough for me for music, a 7" woofer in a 2-way shoud be good enough for an HT center channel.
Merlinx76,
You could easily make this into a three way speaker with a 4.5 or 5.25 midrange and an 8 inch woofer. If you do this you can relax the lower crossover point but bear this in mind. Voice is right in the 150-600 Hz range so if your crossover is in this range it must be very well designed.
It would be more desirable to have the tweeter crossover frequency moved up to 2500 or 3000 which can be more easily done with a smaller midrange.
A couple of pointers to get really good high range sound. Of course you will need shielded drivers but find a tweeter with a low free air resonance around 700 - 900 Hz. And then if you can realize a 2500 - 3500 upper crossover you will have the tweeter covering only the musical overtones. This is desirable because when a tweeter is covering upper midrange tones you get a very poor timbre quality this is especially true with low cost tweeters. They can reproduce the sound but not with accurate timbre below 2000 - 2500 Hz.
You will need to get a midrange speaker with a very natural sound and that has smooth response up to at little above the upper crossover frequency. To get good timber quality from the midrange it is absolutely imperative that it is not put into too small of an enclosure. Often a small enclosure is placed over the midrange but this will kill the quality of the sound. This speaker needs to breath. It's best if you think of the midrange speaker as a fullrange that can't do the top two and bottom most octave.
It is a mistake to think that it is a waste to use the woofer for only one or two octaves. This is what it does best and the most natural and coherant sound comes when you have one speaker reproducing all of the fundamentals. So the midrange should ideally cover 70 - 5000 Hz but more realistically it will cover 70 - 2500 or 140-2500. There are good designs that forego this methodology but they require extensive testing and development. You are more likely to succeed as a DIY'er if you try to stay close to this goal and find drivers that will work for you.
By going to a three way you have far less chance of critically damping the speaker but you should be able to get very good sound anyway. You can widen the bottom of the pyramid shape to give more volume for the woofer. I would create a seperate chamber for the midrange and tweeter by having a solid MDF shelf separate the two. You can then tune the woofer for the most desired bass performance and it's acoustic energy will not modulate the midrange speaker.
I feel that aperiodic enclosure is best for the midrange as it gives the best transient response in a smaller chamber. Therefore the timbre will be more natural.
Hezz
You could easily make this into a three way speaker with a 4.5 or 5.25 midrange and an 8 inch woofer. If you do this you can relax the lower crossover point but bear this in mind. Voice is right in the 150-600 Hz range so if your crossover is in this range it must be very well designed.
It would be more desirable to have the tweeter crossover frequency moved up to 2500 or 3000 which can be more easily done with a smaller midrange.
A couple of pointers to get really good high range sound. Of course you will need shielded drivers but find a tweeter with a low free air resonance around 700 - 900 Hz. And then if you can realize a 2500 - 3500 upper crossover you will have the tweeter covering only the musical overtones. This is desirable because when a tweeter is covering upper midrange tones you get a very poor timbre quality this is especially true with low cost tweeters. They can reproduce the sound but not with accurate timbre below 2000 - 2500 Hz.
You will need to get a midrange speaker with a very natural sound and that has smooth response up to at little above the upper crossover frequency. To get good timber quality from the midrange it is absolutely imperative that it is not put into too small of an enclosure. Often a small enclosure is placed over the midrange but this will kill the quality of the sound. This speaker needs to breath. It's best if you think of the midrange speaker as a fullrange that can't do the top two and bottom most octave.
It is a mistake to think that it is a waste to use the woofer for only one or two octaves. This is what it does best and the most natural and coherant sound comes when you have one speaker reproducing all of the fundamentals. So the midrange should ideally cover 70 - 5000 Hz but more realistically it will cover 70 - 2500 or 140-2500. There are good designs that forego this methodology but they require extensive testing and development. You are more likely to succeed as a DIY'er if you try to stay close to this goal and find drivers that will work for you.
By going to a three way you have far less chance of critically damping the speaker but you should be able to get very good sound anyway. You can widen the bottom of the pyramid shape to give more volume for the woofer. I would create a seperate chamber for the midrange and tweeter by having a solid MDF shelf separate the two. You can then tune the woofer for the most desired bass performance and it's acoustic energy will not modulate the midrange speaker.
I feel that aperiodic enclosure is best for the midrange as it gives the best transient response in a smaller chamber. Therefore the timbre will be more natural.
Hezz
I know this will sound like I am a heretic, but an MTM on its side is not necessarily going to beam.
In the Early 80s Joe D'Apolito published an article in speakerbuilder (now Audio Express) showing that with a 3rd order acoustic slope a vertically arranged MTM would have quite even vertical polar response. Even orders will beam, but odd orders give good vertical dispersion.
It stands to reason that if you are careful to get a third order acoustic slope a horizontal MTM will have good horizontal dispersion. I have had good results using horizontal MTMs as center speakers. I mount the drivers as close together as my woodworking skills allow - about 1/8" between frames.
Hezz - what was the crossover configuration and driver positioning in your MTMs?
In the Early 80s Joe D'Apolito published an article in speakerbuilder (now Audio Express) showing that with a 3rd order acoustic slope a vertically arranged MTM would have quite even vertical polar response. Even orders will beam, but odd orders give good vertical dispersion.
It stands to reason that if you are careful to get a third order acoustic slope a horizontal MTM will have good horizontal dispersion. I have had good results using horizontal MTMs as center speakers. I mount the drivers as close together as my woodworking skills allow - about 1/8" between frames.
Hezz - what was the crossover configuration and driver positioning in your MTMs?
Guys,
I don't mean to imply that a horizontally oriented MTM can't sound good. In fact it can and if the crossover is properly designed it can suceed rather well.
I think this is not the best approach for a first time DIY'er unless space and layout constraints demand it.
The crossover in my center is the one designed by Madisound for the Vifa center channel. I think this speaker was designed to be a universal solution but it obviously sounds better in the vertical orientation. Because I didn't actually design the crossover myself I can't remember what it's topology is.
The driver topology was the standard tweeter in the middle. I used the speaker horizontally for a long time and it sounded OK, but I like it much more now. It has a much more full robust sound which is in part due to the larger enclosure, part due to energy distribution differences.
The reason I like the integrated TV speaker two way above is because it offers so much sound quality for the money spent. With a high end cabinet build quality it will humble many more complex speakers. It is also useful as a home theater design organization because it leaves room to project on the wall above the TV with a front projector in the future.
Hezz
I don't mean to imply that a horizontally oriented MTM can't sound good. In fact it can and if the crossover is properly designed it can suceed rather well.
I think this is not the best approach for a first time DIY'er unless space and layout constraints demand it.
The crossover in my center is the one designed by Madisound for the Vifa center channel. I think this speaker was designed to be a universal solution but it obviously sounds better in the vertical orientation. Because I didn't actually design the crossover myself I can't remember what it's topology is.
The driver topology was the standard tweeter in the middle. I used the speaker horizontally for a long time and it sounded OK, but I like it much more now. It has a much more full robust sound which is in part due to the larger enclosure, part due to energy distribution differences.
The reason I like the integrated TV speaker two way above is because it offers so much sound quality for the money spent. With a high end cabinet build quality it will humble many more complex speakers. It is also useful as a home theater design organization because it leaves room to project on the wall above the TV with a front projector in the future.
Hezz
Let's consider drivers for this if I were to go 3 way. The midrange is obviously the most important so I would guess that would be the best place to start. What's a good midwoofer or widerange speaker that I could use from 150 hz to at least 2.5khz, preferably 3khz. It needs to have these qualities:
1 - very natural sounding over this range
2 - relatively easy to work with
3 - decent SPL capabilities for moderate listening levels (I will use this occasionally for 5 channel music. The power handling of a lot of widerange drivers has me concerned although it seems it is often made up for with high sensitivity)
4 - preferably 6 or 8 ohm (I do use 4 ohm on my amp on the other channels but it's only rated for 6 to 8 ohm)
I was looking at some Fostex wideranges and the some of the 6-6.5" ones don't look that bad to me up to 3khz on one of them the response was better 30deg off axis than at 0 deg.
One driver that is all over this forum that I would like to hear is the Vifa P13 and it's nice and cheap.
Will the midrange have to be shielded at this distance? because that really limits the choices. I have a speaker that's quite close to my TV now with no problems (magnet about 9" from the picture tube, quite close to where the midrange would be). Is there another way to shield the driver or enclosure?
1 - very natural sounding over this range
2 - relatively easy to work with
3 - decent SPL capabilities for moderate listening levels (I will use this occasionally for 5 channel music. The power handling of a lot of widerange drivers has me concerned although it seems it is often made up for with high sensitivity)
4 - preferably 6 or 8 ohm (I do use 4 ohm on my amp on the other channels but it's only rated for 6 to 8 ohm)
I was looking at some Fostex wideranges and the some of the 6-6.5" ones don't look that bad to me up to 3khz on one of them the response was better 30deg off axis than at 0 deg.
One driver that is all over this forum that I would like to hear is the Vifa P13 and it's nice and cheap.
Will the midrange have to be shielded at this distance? because that really limits the choices. I have a speaker that's quite close to my TV now with no problems (magnet about 9" from the picture tube, quite close to where the midrange would be). Is there another way to shield the driver or enclosure?
Hezz,
I wasn't trying to invalidate your experience, I just wanted to see if it matched theory. I never measured my center channels' dispersion, so I don't know for sure that i had no lobing. All I can say is they sounded the same in any seat on the couch.
My beef is really with the naysayers who automatically rule out a horizontal MTM. Repeat anything often enough unchallenged and it becomes the truth. I just didn't want that to happen.
I do like your TV stand concept and when my projector is done my center channel will probably be rebuilt into a laid back TMM version similar to yours.
I wasn't trying to invalidate your experience, I just wanted to see if it matched theory. I never measured my center channels' dispersion, so I don't know for sure that i had no lobing. All I can say is they sounded the same in any seat on the couch.
My beef is really with the naysayers who automatically rule out a horizontal MTM. Repeat anything often enough unchallenged and it becomes the truth. I just didn't want that to happen.
I do like your TV stand concept and when my projector is done my center channel will probably be rebuilt into a laid back TMM version similar to yours.
Thanks Bob,
We all know that in the real world nothing is totally cut and dry and good sounding examples exist of nearly every configuration.
Let me know how your center channel goes if you decid to build it.
Merlinx76,
Of course the choice of drivers is up to you but I will tell you what I would do and then you can think about it.
I think it's best if you can use all shielded drivers but often it's hard to find a shielded woofer.
For a two way I would use a 6.5 or 7 inch mid bass.
For a three way I would use a 4.5 inch or somthing close to that midrange and a 8 inch woofer.
Unless you are using really high end gear it doesn't make much sense to use really expensive speakers. But it doesn't make sense to use the cheapest either.
I like VIFA silk dome tweeters because they are forgiving and sound great for about 35 USD try to get the tweeter in a double chamber shielded kind with a free air resonance of about 700 - 900 Hz. This will keep the tweeters resonance further away from the crossover frequency. Also, tweeters that have too small of a sealed chamber behind them have less natural timbre quality.
Ok the mid range is where you will probably have the most choice and I think for good sound where you should spend the most money. I like the Audax carbon fiber cast frame speakers but I don't know if they are available in a shielded version. They have outstanding timbre quality and are a little expensive but not outragous. Foxtex drivers are very high priced and they make some good full range dirvers but I think you should stay away from a driver that is intended to be a full range driver. Unless you are only going to have one driver.
Look at SEAS and AUDAX and VIFA. Audax aerogel polymer cast speakers are very cost effective and sound good. Focal makes some really nice speakers. What you need to do is find one of the correct size that has a smooth frequency response up to the crossover frequency that you want. Most mid-bass drivers have cone breakups between 2000 - 4000 Hz and you want this breakup zone to be as far above the crossover point as possible.
If you want the upper crossover to be at 2500 or above the speaker needs to be smooth up to a bare minimum of the crossover point better if it is higher.
Parts express has some good quality inexpensive speakers shielded woofers that might work out for the 8 inch. If these were the main speakers I would say to put more money into the woofers but for a center channel it is not very important. The speakers are called Dayton.
Before you select the woofer you need to know about what box volume that you have and how big it can be. This is going to complicate the design process a lot because you haven't got that much volume to play with in a center channel design.
another reason to go with the two-way.
By the way a good two way system in a larger than average enclosure will have better bass performance than you think. So you are not gaining all that much by putting a 8 inch speaker in a smaller volume t han is ideal over a 6.5 inch woofer in an ideal volume. You will move more air but the bass quality will not be as good.
A bump in the bass at about 50 Hz which most speakers have is actually not desireable in a center channel speaker and this is what you are likely to have by using a 8 inch woofer in this volume of cabinet. Though with enough time you may find the right woofer.
Hezz
We all know that in the real world nothing is totally cut and dry and good sounding examples exist of nearly every configuration.
Let me know how your center channel goes if you decid to build it.
Merlinx76,
Of course the choice of drivers is up to you but I will tell you what I would do and then you can think about it.
I think it's best if you can use all shielded drivers but often it's hard to find a shielded woofer.
For a two way I would use a 6.5 or 7 inch mid bass.
For a three way I would use a 4.5 inch or somthing close to that midrange and a 8 inch woofer.
Unless you are using really high end gear it doesn't make much sense to use really expensive speakers. But it doesn't make sense to use the cheapest either.
I like VIFA silk dome tweeters because they are forgiving and sound great for about 35 USD try to get the tweeter in a double chamber shielded kind with a free air resonance of about 700 - 900 Hz. This will keep the tweeters resonance further away from the crossover frequency. Also, tweeters that have too small of a sealed chamber behind them have less natural timbre quality.
Ok the mid range is where you will probably have the most choice and I think for good sound where you should spend the most money. I like the Audax carbon fiber cast frame speakers but I don't know if they are available in a shielded version. They have outstanding timbre quality and are a little expensive but not outragous. Foxtex drivers are very high priced and they make some good full range dirvers but I think you should stay away from a driver that is intended to be a full range driver. Unless you are only going to have one driver.
Look at SEAS and AUDAX and VIFA. Audax aerogel polymer cast speakers are very cost effective and sound good. Focal makes some really nice speakers. What you need to do is find one of the correct size that has a smooth frequency response up to the crossover frequency that you want. Most mid-bass drivers have cone breakups between 2000 - 4000 Hz and you want this breakup zone to be as far above the crossover point as possible.
If you want the upper crossover to be at 2500 or above the speaker needs to be smooth up to a bare minimum of the crossover point better if it is higher.
Parts express has some good quality inexpensive speakers shielded woofers that might work out for the 8 inch. If these were the main speakers I would say to put more money into the woofers but for a center channel it is not very important. The speakers are called Dayton.
Before you select the woofer you need to know about what box volume that you have and how big it can be. This is going to complicate the design process a lot because you haven't got that much volume to play with in a center channel design.
another reason to go with the two-way.
By the way a good two way system in a larger than average enclosure will have better bass performance than you think. So you are not gaining all that much by putting a 8 inch speaker in a smaller volume t han is ideal over a 6.5 inch woofer in an ideal volume. You will move more air but the bass quality will not be as good.
A bump in the bass at about 50 Hz which most speakers have is actually not desireable in a center channel speaker and this is what you are likely to have by using a 8 inch woofer in this volume of cabinet. Though with enough time you may find the right woofer.
Hezz
Thanks guys for all the great input so far!
Here's a couple of fostex 6.5" wideranges that look pretty good up to 3k. One thing that concerns me is that these drivers have high fs and low qts will they sound good in a sealed enclosure if I cross them at 150 hz?
this one actually looks best at 60deg off axis... ff165k
here's another... fe167e
Here's a couple of fostex 6.5" wideranges that look pretty good up to 3k. One thing that concerns me is that these drivers have high fs and low qts will they sound good in a sealed enclosure if I cross them at 150 hz?
this one actually looks best at 60deg off axis... ff165k
here's another... fe167e
Something I am noticing is that I will likely need to go with a 6.5" -7" woofer if I want the sealed box to match my mains in the low end. With the crossover at 150hz, the woofer is attenuated quite a bit in the passband. Even with a pair of woofers, the midrange will have to be attenuated quite a lot if it's efficient.
So I guess high efficiency for the mid is not required for this design. Would having to pad the mid a lot be a bad thing since it is playing into the midbass region?
So I guess high efficiency for the mid is not required for this design. Would having to pad the mid a lot be a bad thing since it is playing into the midbass region?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.