first diy tqwt fullrange speakers

[bernardodda]

hello everybody,
First of all sorry for my English.
Second, congratulations for this great forum.
I'm new in this hifi diy things so please be pacient
I'm looking for some full range speakers and i've got some questions but I'm not sure if they make sense,

-if one purpose of fullrange speakers is not being out of phase why should I go for back loaded horn? doesn't the sound comes out of phase? the distance traveled by the sound from the drive and from his back is not the same...

-from all the designs I've seen TQWT is the one that makes more sense to me
but I'm too confused with what driver to choose...
first I thought of fostex fx120 but then I listened to some fostex monitors NX-6A and I really hated the sound of them, they were very metallic, not soft at all, so I really got scared about buying these fx120, then I saw the the tang band drivers but I read somewhere that the w8-1808 where not suitable for TQWT, but didn't said why...

-These are just a few of my questions...
thanks for your patience

just for the record, I like all kinds of music but some kinds I just listen in good systems like opera, my father has a pair of b&w 805, and I really like them, but I don't have the money (or the status ) , neither is fun to buy something already done...
I like a "relatively powerfull" bass, but what I really like is a fast stopping bass (that doesn't get too much around himself) and detailed treble

thanks
bernardo

[chrisb]

A few thoughts re Fostex drivers / etc:

Fostex is one of the larger audio transducer manufacturers around and produces a substantial line of loudspeaker drivers for DIY/OEM markets as well as finished speaker models, using a wide range of design goals, engineering details and combinations material technologies. They don't all sound the same, and probably very few folks have sampled even a small percentage of the entire spectrum.

The models you heard were a self-powered small near field monitor - there could be lots of reasons you didn't care for what you heard, not all of which might be entirely the speaker's fault - and that shouldn't dissuade you from considering Fostex for a DIY project.

As you mentioned the FX120 - this is a driver that many folks here have had experience with, myself included, and price considerations aside (it's not what I would classify as "entry level"), it's quite suitable for a DIY build - I've only heard it in a couple of designs other than the "factory recommended" DBR. For the FX120, you might want to take a look at this one:

Fostex FX120 DIY ML-TQWT (Transmission Line) Speaker Project

disclaimer: I could be accused of being a long time fan-boy for Fostex - there are lots of other manufacturers of very decent sounding, affordable drivers for FR DIY speaker projects - Dayton, Fountek, Mark-Audio, Tang-Band, and numerous others that could be suggested to you.

[bernardodda]

thanks for the fast reply.
that fostex project was what made me think about fx120 I really think it's a nice project
I know it's a strange question to ask but what's your opinion about the fx120 drivers?

Although it's my first diy speaker project i'm always looking for more in terms of sound so I really want something good, I'm really patient, this project started in my mind 4 months ago and I'm trying to read as much as I can.

I speak a lot with sound engineers friends but they mix hifi with stage sound and I'm more and more confused each time...
what speakers would you advise me I think I can go up to 400€ but is it worth it or is this kind of price some muddy terrain between HiFi (lowther) and Cost-Effect (like the fx120)

[ra7]

The TQWT is a great first project. It is a very flexible and forgiving cabinet. That is, it will work with a number of different drivers. Build this cabinet once and then you can swap in and swap out different drivers. The choices are endless - fostex, audio nirvana, lowthers and so on.

[chrisb]

Originally Posted by bernardodda

thanks for the fast reply.
that fostex project was what made me think about fx120 I really think it's a nice project
I know it's a strange question to ask but what's your opinion about the fx120 drivers?

not strange question at all - much of these forum posts deal with intangible subjective opinions -

I quite like the FX120, and while I haven't heard it in the design cited, am reasonably confident I' could live with them.

Although it's my first diy speaker project i'm always looking for more in terms of sound so I really want something good, I'm really patient, this project started in my mind 4 months ago and I'm trying to read as much as I can.
I speak to a lot of sound engineers friends but they mix hifi with stage sound and I'm more and more confused each time...
what speakers would you advise meI think I can go up to 400€ but is it worth it or is this kind of price some muddy terrain between HiFi (lowther) and Cost-Effect (like the fx120)

At the risk of offending any "sound engineers" -(whether of the recording / mixing, Public Address / live concert sound, or home audio system varieties), the reason many of us DIYers spend decades in this hobby - often after many more consuming commercial products - is dissatisfaction with same.

What is considered a "cost-effective" driver certainly varies among individuals, and often due to vagaries of global marketing/pricing. The FX120 retails in US/Canada for approx $125 ea - there are several approximately same sized drivers within the Fostex line that can perform very well in an easily constructed enclosure for less than half that amount - the first that come to mind would be the FE126E or FF125WK. I've heard both, and the former really wants a BLH enclosure, while the latter works very well in a moderate sized vented enclosure, perhaps something very much like the MLTL posted earlier - although dimensions would need to be revisited.

[planet10]

Originally Posted by bernardodda

-if one purpose of fullrange speakers is not being out of phase why should I go for back loaded horn? doesn't the sound comes out of phase? the distance traveled by the sound from the drive and from his back is not the same...

-from all the designs I've seen TQWT is the one that makes more sense to me
but I'm too confused with what driver to choose...

What you say is true. Do consider that a standard TQWT is a variation on a tapped horn. As well, most small horns get the lowest parts of their range from TL action, so these 2 designs are not far removed from each other. Mass-Loading a TQWT (as in the link from Chris), restricts the terminus bandwidth and makes it much more of a TL.

FX120 is a fine driver. It won't go as low, or provide as much LF grunt as W8-1808 (which should be out of your budget range anyway), but i'd give it the lead everywhere else. (for the price difference a pair of nice woofers could be added, if you really need the bass weight). 1808 should be workable in an ML-TQWT but will be big.

To really help out, you'll need to answer the standard room size, amplifier, listening sytle questions.

dave

[bernardodda]

thanks for all the answers, I'm quite tempted to go for something like the fostex fx120 ML-TQWT but adapted to the TB w8-1808, the impression I have is that with this kind of case design the bass will stay more controlled/dry , is this true?
as to the speakers are these a good choice or are there other options for these amount of money?
as I said a really clean bass is what I like, and (like most of us) a linear sound trough mids and HF.

as for the room size, amp and listening style,

-well, I have a old granite house with a big living room ( 5x12 meters) where I want to put these..

-I really don't have a good amp but that will be my next diy project, although I've seen some interesting things on ebay, "topping tp40 or tp60" I'm curious about these.

- My listening style goes from Opera to Classic Music, Dead can dance, Lhasa, Jazz, World Music etc
thank you
Bernardo

[planet10]

Originally Posted by bernardodda

something like the fostex fx120 ML-TQWT but adapted to the TB w8-1808

Start from scratch is a better description than adapt. Only the idea of the basic folding can be retained.

dave

[chrisb]

Originally Posted by bernardodda

thanks for all the answers, I'm quite tempted to go for something like the fostex fx120 ML-TQWT but adapted to the TB w8-1808, the impression I have is that with this kind of case design the bass will stay more controlled/dry , is this true?
as to the speakers are these a good choice or are there other options for these amount of money?
as I said a really clean bass is what I like, and (like most of us) a linear sound trough mids and HF.

as for the room size, amp and listening style,

-well, I have a old granite house with a big living room ( 5x12 meters) where I want to put these..

-I really don't have a good amp but that will be my next diy project, although I've seen some interesting things on ebay, "topping tp40 or tp60" I'm curious about these.

- My listening style goes from Opera to Classic Music, Dead can dance, Lhasa, Jazz, World Music etc
thank you
Bernardo

For a room that size and your listening tastes, I'd suggest that you might want to consider other driver / enclosure styles - this sounds like a room eminently suited to a larger BLH and more efficient driver - i.e. FE166E / BIB / Vulcan etc.

Woden Design | Victor



as to amps, these babies don't need much more than 10-15W to get started - how far beyond depends on the room and your pain threshold

[ODougbo]

I did some experimenting with FX 120 speakers. I was tempted to build a T-line enclosure but the author’s review concerning the bass was worrisome. However, I do plan on building a pair one day.

Too much to type but the cabinets shown work well; e.g. fantastic bass, mid and highs. The imaging is almost eerie, (my eyes keep looking at a blank wall). There are actually 8 chambers, four per side, also 4 drivers are used; one pair forward, one pair back.

The speakers are not metallic sounding at all; many have said that they need 6 months to break in (which these have). I will say, the FX120 are very nice; not the easiest speaker to work with, although it will perform nicely.